MonoChloramine Chemistry

Chloramines are formed by the reaction of ammonia and aqueous chlorine (i.e., HOCl). At first, chloramines were utilised for taste and also odour control. However, it was quickly recognised that chloramines were much more secure than free chlorine in the circulation system and consequently were found to be reliable for regulating bacterial regrowth. During the past two decades, concern regarding chlorinated organics (e.g., THM and HAA formation) in water treatment and distribution systems raised interest in chloramines since they form few byproducts (DBPs).

Chloramines are formed from the reaction of chlorine and ammonia. The resulting blend may have monochloramine (NH2 Cl), dichloramine (NHCl2 ), or nitrogen trichloride (NCl3 ). When chlorine is distributed in water, rapid hydrolysis occurs according to the following reaction:

Cl2 + H2O → HOCl + H + Cl 

The equilibrium constant (K eq) at 25 ° C is 3.94 x 104 M¯¹ for this reaction. In diluted water solutions, at a pH of more than 3, the forward reaction is complete. Hypochlorous acid (HOCl) is a weak acid that dissociates as it adheres to:

HOCl OCl + H+ pKa  = 7.6

Relative proportions of HOCl and OCl are dependent upon pH. Both chlorine species in the above reactions are powerful oxidants, efficient in responding to many substances existing in water. In aqueous solutions with pH 7.0 to 8.5, HOCl reacts swiftly with ammonia to form inorganic chloramines in a series of contending reactions (White, 1992).

The simplified stoichiometry of chlorine-ammonia reactions are as follows: 

NH3 + HOCl → NH2 Cl + H2O (monochloramine)
NH2Cl + HOCl → NHCl2 + H2O (dichloramine)
5NHCl2 + HOCl → NCl3 + H2O (nitrogen trichloride)

These competing reactions, and several others, mainly depend on pH and are managed to a considerable degree by the chlorine: ammonia nitrogen (Cl2 : N) proportion. Temperature and contact time also contribute to the reaction process. Figure 1 reveals the standard connections between the chloramine species at different Cl2 : N proportions for pH ranging from 6.5 to 8.5.  

Figure 1:Theoretical Breakpoint Curve

This number indicates that monochloramine is predominately developed when the used Cl2 : N proportion is less than 5:1 by weight. As the used Cl2 : N ratio rises from 5:1 to 7.6:1, breakpoint response occurs, lowering the residual chlorine level to a minimum. Breakpoint chlorination causes the development of nitrogen gas, nitrate, as well as nitrogen chloride. At Cl2 : N ratios over 7.6:1, free chlorine and also nitrogen trichloride are present. 

Figure 2 reveals the partnership between chloramine types as the pH modifications (Palin, 1950). The number shows that dichloramine becomes a dominant species at low pH. 

Figure 2: Distribution Diagram for Chloramine Species with pH

To avoid breakpoint reactions, utilities should keep a Cl2: N ratio between 3 and 5 by weight. A proportion of 6 is optimum for disinfection. However, it is challenging to preserve a stable operation at that point in the breakthrough curve. As a result, a Cl2 : N proportion of 4 is usually accepted as optimal for chloramination.

Additionally, over a day approximately, with no modification of pH or Cl2: N proportion, monochloramine will certainly weaken gradually to dichloramine to a ratio of 43 percent NH2 Cl to 57 percent NHCl2 . Dichloramine is relatively unstable in the presence of HOCl; therefore, pure options of this form of monochloramine are challenging to generate and retain. According to the above formulas, chloramines are developed by the reaction of hypochlorous acid to ammonia. Table 1 below summarises the theoretical doses of chlorine as well as ammonia based upon these solutions. 

Reaction mg Cl2/mg NH3
Monochloramine (NH2Cl) 4.2
Dichloramine (NHCl2) 8.4
Nitrogen Trichloride (NCl3) 12.5
Nitrogen (N2) 6.3
Nitrate (NO3) 16.7
Free residual reaction 9
Table 1: Chlorine Dose Required for NH3  – Cl2 Reaction 

Monochloramine is the preferred chloramine species for disinfecting drinking water. This is due to preference and smell issues associated with dichloramine and nitrogen trichloride. To guarantee that these compounds are not created, standard practice was to limit the chlorine to ammonia proportion to 3:1. However, because of problems such as nitrification and biofilm formation, which can be brought on by excess ammonia, the present technique uses a Cl2 : N ratio in the range of 3:1 to 5:1, with a typical worth of 4:1. 

Table 2 below illustrates the calculated response times for monochloromine development at 25 ° C and at chlorine: ammonia ratio of 3:1 (White, 1992). The rate of reaction of monochloramine formation is sensitive to pH.

pH Time (seconds)
2 421
4 147
7 0.2
8.3 0.069
12 33.2
Table 2: Time to 99 Percent Conversion of Chlorine to Monochloramine

Monochloramine is utilised in drinking water treatment for disinfection and also organism control. Factors of application are based on treatment goals and also contact time disinfection requirements. 

EPA Guidance Manual April 1999 Alternative Disinfectants and Oxidants

Monochloramine generators designed by Nanotech

Primary Use of Monochloramines


The primary use of monochloramine in water systems is as a secondary disinfectant for maintaining a residual in the distribution system. Chloramines are an excellent choice for secondary disinfectants because of the following potential benefits: 

  • Chloramines are not as reactive with organics as free chlorine in forming THMs. 
  • The monochloramine residual is more stable and longer-lasting than free chlorine, providing better protection against bacterial regrowth in systems with large storage tanks and dead-end water mains. 
  • The monochloramine residual is more effective in controlling biofilms because of its superior ability to penetrate the biofilm. Controlling biofilms also tends to reduce coliform concentrations and biofilm-induced corrosion. 
  • Because chloramines do not react with organic compounds, many systems will experience less taste and odour complaints when using chloramines. 

Water systems typically found that conversion from free chlorine to monochloramine as the secondary disinfectant significantly reduced coliform concentrations in the distribution system.

The standard dosage range for monochloramine is in the range of 1.0 to 4.0 mg/L. The minimum residual of monochloramine in the distribution system is typically regulated at 0.5 mg/L. To prevent nitrification in a distribution system, a minimum monochloramine dosage of 2.0 mg/L is recommended. 

Advantages and Disadvantages when using Chloramine: 


  • Chloramines are not as reactive with organics as free chlorine in forming disinfection byproducts (DBPs).
  • The monochloramine residual is more stable, lasting longer than free chlorine. This provides better protection against bacterial regrowth in systems with large storage tanks and dead-end water mains. However, excess ammonia in the network has the potential to cause biofilm. 
  • Chloramines do not tend to react with organic compounds. Several systems will experience fewer taste and odour challenges when using chloramines. 
  • Chloramines are reasonably priced. 
  • Chloramines are manufactured on-site and consumed immediately.


  • The disinfection properties of chloramines are not as strong as other disinfectants found in the market, such as chlorine, ozone, and chlorine dioxide. 
  • Chloramines are unable to oxidise iron, manganese, and sulfides. 
  • When using chloramines for secondary disinfection, it may be necessary to periodically convert to free chlorine for biofilm control in the water distribution system. 
  • Excess ammonia in the distribution lines may lead to nitrification challenges; this occurs mainly in dead-ends and other areas of low disinfection residual. 
  • Monochloramines are less effective as disinfectants at high pH than at low pH. 
  • Dichloramines have treatment and operation challenges. 
  • Chloramines must be made up on site. 

Frequently Asked Questions (FAQ)

How long has monochloramine been used to disinfect potable or drinking water?

  • Monochloramine has been utilised as a drinking or potable water disinfectant for longer than 90 years.
  • Monochloramine has proved to be an effective anti-bacterial cemented by decades of use in Canada, the U.S., Canada, and Great Britain.
  • Typically, monochloramine is used alongside chlorine or chlorine dioxide as part of the drinking water treatment process.
  • Monochloramine helps protect individuals from waterborne illness.

How is monochloramine normally used?

  • Monochloramine is most often made use of to maintain water quality in the pipes.
  • Monochloramine offers a durable defence of water quality.
  • Monochloramine works as an anti-bacterial since it does not dissipate rapidly.
  • Monochloramine aids lower degrees of potentially unsafe disinfection byproducts compared to chlorine.

How is monochloramine used in the disinfection of drinking water? 

  • Monochloramine is used as a secondary disinfection, giving longer-lasting water treatment as the water moves with pipes to customers.
  • Additional disinfection maintains the water’s high quality by eliminating potentially hazardous organisms that might get into the water as it travels through pipelines.
  • Monochloramine may be more beneficial than chlorine in killing specific potentially dangerous organisms in pipes such as those that cause Legionnaire’s disease. 

Can monochloramine be an effective primary disinfectant? 

  • Monochloramine takes a lot longer than chlorine to kill most potentially harmful organisms.
  • Monochloramine can be used as a primary disinfectant, yet the time required for treatment makes it impractical for most utilities.
  • However, because it is much longer-lasting than chlorine, monochloramine is often used as a secondary disinfectant.

Can combinations of disinfectants be used for primary disinfection?

  • Primary disinfection usually includes numerous disinfection steps that may start as the water enters the treatment plant.
  • When used as a primary disinfectant, monochloramine performance is boosted by incorporating it with other disinfectants.
  • The option of which combination of disinfectants to use varies for water utilities based on their demands and requirements. 

Does monochloramine have advantages over chlorine as a secondary disinfectant? 

  • Monochloramine is a lot more chemically stable than chlorine.
  • Monochloramine produces less potentially dangerous regulated disinfection byproducts than chlorine.
  • Monochloramine is longer-lasting than chlorine, making it helpful in killing particular harmful organisms located in pipes such as those that cause Legionnaires’ illness. 

Ultra Filtration

The Ultra Filtration (UF) system is containerized inside a modified shipping container. UF systems remove turbidity, suspended solids, some viruses, and most bacteria. The unit will not remove dissolved solids (TDS). Additional process steps can be added to remove TDS. The unit requires a flat surface with feed and filtrate storage tanks. These tanks usually form part of the site set-up. Nanotech Ultra Filtration system capacities range between 50 – 240 m3/day.

Ultra Filtration Pre-Treatment vs Conventional Pre-Treatment

UF Membrane Pre-Treatment Conventional Pre-Treatment
Provides a physical barrier to particles, thereby giving consistently high quality and reliable feed water to the RO. Removes a proportion of particles but produces poor and inconsistent feed quality to the downstream RO. Operational and feed-dosing problems as well as backwashing operation of sand filters can result in long periods of poor RO feed quality.
Good quality feed to RO means lower frequency of RO cleaning and therefore extended on-stream time. More frequent RO cleaning is required due to poor feed quality, resulting in downtime.
The lifespan of RO membranes is extended hence RO replacement cost is lower. RO membranes may need to be replaced more regularly, resulting in higher operational costs.
Lower requirements for chemical dosing and for RO cleaning, resulting in lower chemical costs. Chemical dosing is required in conventional pre-treatment and with more frequent RO cleaning, more chemicals are also used.
Lower environmental impact. Extensive use of concrete, large footprint, higher energy use, and high chemical waste disposal.

Containerized Ultra Filtration System – Congo
Capacity of 80 m3/day
Compliance requirement – SANS 241

Why should you choose Nanotech?

  • Focused on COMPLIANCE!
  • After-sales service can be provided.
  • Skills transfer to maintain the system.
  • System designed and fabricated following ISO 9001 parameters.
  • System guaranteed to provide the quality as required – Complete scope of contaminants addressed.
  • Process selection based on system requirements carefully and accurately designed to cater to the end-user needs.

Ultra Filtration & Reverse Osmosis – Ghana
Capacities: UF – 300 m3/h & RO – 200 m3/h
Tailings wastewater recovery system

Contact our capable team today for a consultation.

Reverse Osmosis

Understanding Reverse Osmosis

Reverse Osmosis is commonly referred to as RO. The process involves the removal of total dissolved solids (TDS) from a feed water stream by driving water through a semi-permeable RO Membrane.

Nanotech’s RO Units

Reverse Osmosis technology is used to remove dissolved solids from water.  The removal mechanism of RO systems is different from the removal mechanism of filtration. Physical holes do not exist in the RO membrane. It is more likely that water molecules diffuse between the structures of the membrane polymer by bonding through segments of the polymers’ structure.

The dissolved salts and organics are retained on the concentrate side of the membranes. Reverse Osmosis is a process of separation. The feed stream entering the membrane is separated into the clean water stream, also called the permeate stream. The second stream is known as the concentrate stream, also called the brine stream. As the water passes across the membrane surface the water permeates the membrane. The water molecules permeating the membrane leave behind the solids. This is creating a concentration of salts in the brine side.  The permeate stream for the RO system is used in the process while the brine stream is discarded to waste. The brine stream typically accounts for 20 – 25% of the feed stream. After a detailed design, the simulated water stream qualities will be available.

Containerized Sand Filter RO System
Capacity of 15 m3/h – Angola
Compliance requirement – SANS 241

Benefits of Reverse Osmosis

  • Easy to operate.
  • Flexibility in the production of water to the required specification.
  • Increased membrane water production rates (flux rate) reduces footprint.
  • Developments in membrane technology allow for increased water recoveries.
  • Can be containerized and mobile for the production of potable water in arid regions where no suitable potable water source is available.

RO System – Sasol
Capacity of 210 m3/h
Internal Sasol standards and quality requirements

Why should you choose Nanotech?

  • Focused on COMPLIANCE!
  • After-sales service can be provided.
  • Skills transfer to maintain the system.
  • System designed and fabricated following ISO 9001 parameters.
  • System guaranteed to provide the quality as required – Complete scope of contaminants addressed.
  • Process selection based on system requirements carefully and accurately designed to cater to the end-user needs.

Contact our capable team today for a consultation.

Chlorine Dioxide

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Chlorine Dioxide (Cl02) was discovered in 1817 by Sir Humphrey Davy. In the early 1900s the chemical was recognised as an antimicrobial biocide, and since then has been widely known for its disinfecting properties. Chlorine Dioxide Ready-toUse kills microorganisms by disrupting the transportation of nutrients across the cell wall and because of that it has been labelled and recognised as a superior disinfectant. Further recommended by the EPA as a solution to trihalomethanes (THM’S), applied by Nanotech as: Clear

Clear (Chlorine Dioxide Ready-to-Use) is a neutral chlorine compound, different to chlorine in both its behaviour and chemical structure. The green-yellowish synthetic solution is a volatile and very strong molecule. When diluted, Cl02 is a free radical but at high concentrations, the gas reacts with reducing agents. When comparing Chlorine Dioxide Ready-to-Use to other biocides (chlorine, ozone, hydrogen peroxide, hypochlorous acid) it has a significantly lower oxidation capacity, however, it is strong enough to attack bacterial and biological material bonds.

Chlorine Dioxide Ready-to-Use is effective against Giardia and Cryptosporidium, bacteria, viruses, mould, fungi, and algae. The chemical applications span from both domestic and  industrial applications:

Clear has been successfully applied in the following industrial applications:

  • Power and Industrial
  • Food and Beverage
  • Water Utilities
  • Oil and Gas
  • Hospitality
  • Agriculture
  • Healthcare
  • Abattoirs
  • Aviation
  • FMCG

Clear Performance

  • Up to 66% reduction of TOC in the clarification process
  • 5 times more powerful per ppm (according to WHO CT values)
  • Reduction in trihalomethane (THM) formation potential
  • Control of contaminant bacteria and organics
  • Effective through a broad range of pH
  • Increase in water Micro Compliance
  • Enhanced disinfection contact time
  • Colour, odour and taste removal
  • Ion and manganese reduction
  • Biofilm reduction and removal
  • Residuals over long distances
  • Broad-spectrum disinfection
  • Combating legionella
  • Hard surface sanitiser
  • Selective oxidizer
  • Inactivates virus
  • Less corrosive

Download Chlorine Dioxide MSDS

Clear Ready-to-Use packaging:

Clear Powder packaging:

Clear 8kg Powder Kit
The Clear Powder formulation makes up 440 Litres of 3 000 ppm Chlorine Dioxide RTU
Safe and ready-to-use within 30 minutes

Download Mixing Instructions

Grease Trap Treatment

Why you should care about the maintenance of your grease trap?

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The problem is that fats, oils, and grease (FOG) that enter the grease trap, are flushed out with time into the drainpipe network. The FOG congeals inside the pipes and starts blocking the pipes.

In your kitchen, it causes drain water to push back into your kitchen and foul odours (hydrogen sulphide emission (H2S), creating very unhygienic conditions.  Downstream of your kitchen, the FOG that did make it past the blockages, cause blockages over time, failure of pumping stations in the sewer network, increased maintenance, and challenges on the sewage treatment system. 

Why is that a problem?

Well simply stated, blocked drains mean the water from the drains and everyday use cannot flow freely to the sewer network, pushing back into the pipes, and finally into the washbasin.  This causes havoc in the kitchen. The following happens:

  • Someone needs to attend to the problem, this is time-consuming and costly.
  • The dishes start mounting as the basin cannot be used.
  • The waste might push back into floor drains, and the floor might be covered in drain wastewater.
  • The kitchen starts smelling foul and unhygienic conditions prevail.
  • Plumbers are called out if the problem persists. This is costly.

The drain is cleared by the plumber, and all returns to normal, UNTIL THE NEXT TIME…

How can this cycle be prevented?

There is a solution that can continuously attend to the problem so that you don’t have to.

With bio-augmentation, the FOG in the grease trap can be liquified and digested to harmless components that can flow through the drain network, and out to the local sewage system.

Your grease trap is one of your kitchen’s most valuable assets. Keeping it properly maintained prevents a whole host of issues, from unpleasant odours to blocked drainpipes, kitchen shutdowns, and even fines.

It’s estimated that across South Africa, millions of Rands are spent each year on unclogging drain pipes from FOG.

What is FOG – (Fats, Oils, and Grease)

FOG is an acronym for the fats, oils and greases coming from vegetable, plant or animal sources during cooking. It exists as:

  • Yellow grease that results from deep frying,
  • Brown grease that contains FOG that floats or settles into solids.

Both types of grease can cause challenges in your drain system and grease traps.

How does it look in your piping system?

Well, blockages start forming and only get worse with time. See the pictures below:

Grease Trap Treatment

Below is an indication of a blocked sewer and blocked pipes:

Grease Trap Treatment

No problem, we can help!

The solution is Bio-augmentation, a well known and applied solution all over the world.

What does Bio-augmentation mean?

Well, Bio-augmentation is the process of using selected microbes and enzymes to biologically digest and clean up a specified contaminant, in this case, FOG in your fat trap.

This is a 2-step approach to degrade FOG’s in grease traps. Specific non-pathogenic microbes are formulated and introduced into the grease traps. These microbes selected form enzymes, primarily lipase, which break down fats and oils (triglycerides) to fatty acids and glycerol. However, fatty acids tend to form colloidal particles that may aggregate and precipitate from solution as a result of environmental changes (pH, temperature) and can cause clogging. Additionally, in the bioaugmentation process, the microbes introduced digest (metabolise) the fatty acid and glycerol further, (in the presence of oxygen) to carbon dioxide and water. During the process, they use simple and complex carbohydrates as a food source, and after complete digestion. See below image:

Grease Trap Treatment

For your grease traps, the bioaugmentation treatment process is used to ensure that the microbes that are selectively chosen are the best to digest FOG, they remain the dominant population in the system and by changing the microbial community to include specific microbes, the characteristics of the entire microbial community is improved. 

As mentioned above, the correctly chosen microbial strain can produce enzymes, including lipase. In simple terms, microbe and enzyme treatment converts unsaturated fats (containing double bond) to saturated fats (containing single bond), resulting in increased biodegradability. Thus, it splits long-chain fatty acids and double bonds.

The microbe strain produces enzymes, with specific tasks, as required. The following enzymes have the following job:

  • Lipase – Breaks down fats/grease (triglycerides) into glycerol and fatty acids. This Enzyme is applicable to the product for FOG treatment. This enzyme breaks down the FOG in the grease trap, and assists in the prevention of downstream blockages, due to deposits.

Other enzymes in the product include:

  • Protease – These enzymes break down proteins (e.g. meat products) into amino acids.
  • Amylase – These enzymes catalyse the break-down of starch into sugars which are then further used as a food source for the microbes. Starch acts as a glue for dirt.
  • Cellulase – breaks down cellulosic material.
  • Urease – catalyses the hydrolysis of urea into break-down products.
  • Xylanase – help in breaking down plant cell walls.

The market requires a reliable and easy to operate solutions.  For this reason, Nanotech has packaged a bioaugmentation solution, NanoTrap, that utilizes microbes and enzymes in our product,  suited for the following applications:

  • Restaurants,
  • Hospital kitchens,
  • Hotels + Holiday Resorts
  • Mining Camps, Hostels, Lodges
  • Industry
  • Shopping centres and Retail shops – Anywhere food is prepared and served.

Would you like to see Evidence of this?

When correctly applied the treatment will yield results in 3-6 weeks, depending on the contamination.

The below image indicates a grease trap before and after treatment.

When hot water is flushed down the trap, the layer will be liquified and flushed out, only to settle in the piping system downstream

Grease Trap


Contact us for a consultation

As a summary, what should you consider, before using the product?

  • The product is applied as a maintenance process to treat FOG’s in the grease trap and to prevent build up in the sewer system.
  • The treatment must be considered as a drain cleaner, not a drain opener.
  • It is used in places were food preparation and processing produce large quantities of wastewater with high quantities of FOG’s.
  • Left untreated the FOG can block drainage systems.
  • The preparation area or kitchen starts smelling foul and unhygienic conditions prevail, which eventually leads to expensive and inconvenient cleaning of the blocked drain.
  • The product will yield the best results when the effluent pH is around 7.
  • The flow through the grease trap provides mixing and oxygen supply, which is required for effective results. This is important, as no flow, will result in poor results.
  • Sufficient Hydraulic retention time is required. What does this mean? The time the effluent spent in the grease trap and piping system needs to be sufficient for the microbes to start digesting the FOG. We will assist in determining if your grease trap has optimum HRT.

Very important – Please note the following:

  • Reduce the use of non-biodegradable detergents, as far as possible. Bio-degradable alternatives are available and have proven to be advantageous. Contact us to try out the Nanotech range
  • Do not use anti-bacterial or biocidal products, as this will prevent the treatment from working.
  • Do not use any harsh chemicals such as strong acids or bases as this will kill the bacteria.

What are the key features we like you to know?

  • All our ingredients are readily biodegradable and comply with the standard test method specified under OECD 301.
  • They contain active natural bacteria.
  • Compatible with downstream water treatment and re-use systems.
  • Competitive exclusion of pathogenic or undesirable microbes.
  • Global Green Tag Certified (by technology partner)
  • Our product is long-lasting and has a 24 months shelf life.
  • Product is very safe:
    • Non-hazardous.
    • Non-carcinogenic.
    • Non-genetically modified.
    • Non-pathogenic

What is the next step? Why should you buy from Nanotech?

Our grease trap treatment is proven in the market, and the benefits to you are evident. In addition to our expertise in assisting with your challenge, we can offer you a  30-day 100% money-back guarantee, if the product does not perform as required, after correct application, and optimisation by us.

This is us, putting our money, where our confidence lies…. No risk to you….


Contact our capable team today for a consultation.

Chlorine Dioxide Generators

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When you think of clean water, you think about a water disinfectant. But how do you disinfect water? What do you use? And how can you tell if your water is properly disinfected? We think chlorine dioxide generators.

Chlorine dioxide (ClO2) can fully disinfect your water because it is a broad-spectrum biocide that is an extremely effective disinfectant against all bacteria, viruses, mould, fungi, algae, and spore formers such as Giardia and Cryptosporidium.

At Nanotech, we have rebranded our chlorine dioxide as “Clear”. It is a proudly South African-engineered solution providing the entire continent with a locally formulated disinfectant that produces world-class results.


Have you or your children ever felt sick or weak? Impurities that enter our bodies often have that effect on us. Our natural resources are being polluted and our rivers now carry diseases like typhoid fever and cholera. We need to address the deterioration in our water quality by ensuring all our water is properly disinfected. If you generate chlorine dioxide, you know your water is free from all harmful bacteria and viruses.

Nanotech has been involved in producing chlorine dioxide for years, building chlorine dioxide generators locally and extensively testing all the available chemical technologies. Each one of these disinfection technologies has its own unique advantages and disadvantages. Nanotech has completely re-engineered the generation of chlorine dioxide. We have adapted the process to changing customer requirements and our specially formulated chlorine dioxide as disinfectant is called Clear for a reason – we have removed all those dangerous by-products and contaminants with their nasty side-effects that are part of some other manufacturers’ processes. That is why the Clear chlorine dioxide is your number one alternative disinfectant technology.

Clear chlorine dioxide acts by first destroying the cell membrane of the bacteria and then the nucleus by chemical oxidation, not chlorination. Because the organism is destroyed, no resistant strains can develop, and chlorine dioxide can be used on a continuous basis without the need for alternating biocides.

Secondly, chlorine dioxide is a fast-acting and extremely effective disinfectant, functioning as a highly selective oxidiser with a reduced environmental impact.

Many disinfectants or alternatives have wasteful reactions that produce several disinfection by-products (DBPs), but chlorine dioxide minimises wasteful reactions, which means that it is a far more proficient disinfectant and oxidising agent for your water treatment processes.

Clear has been successfully proven in:

  • The disinfectant of choice in waste and potable-water treatment plants to improve water’s micro bacterial compliance.
  • Preferred disinfectant at municipalities and boreholes for maintaining the disinfectant residual [ClO2] over the reticulation or network.
  • The improvement of the colour and the removal of odour and taste.
  • The oxidation of iron and manganese.
  • Cooling-tower biocide replacement.
  • Process improvements for industrial clients, with disinfection in CIP procedures, quality control of incoming water, and microbial process compliance.
  • Improving the compliance requirements of swimming pools.

After numerous trials later, we have found the perfect balance between reliable components, cost-effective precursor chemicals, performance-based methodologies, and good maintenance practices to manufacture chlorine dioxide generators. This delivered disinfected water that is 100% compliant with the regulations of local authorities in terms of the consumption of potable water.

The Lotsane Dam in Botswana is a shining example of how our chlorine dioxide, as a superior disinfectant, assisted the client in achieving 100% compliance. The dam feeds 22 villages ranging in distance from 4,2 to 128 km from the point of disinfection. After only five weeks of disinfection with chlorine dioxide, compliance levels rose to 100% from the previously unacceptable level of 37%. The total coliforms, faecal coliforms, E.coli, and faecal streptococci readings were <1 CFU/100 ml at a pH of between 7,42 and 8,54.

These results prove that the disinfection technologies developed by Nanotech is not only efficient but also superior to other similar technologies currently available in the market. Nanotech’s market-leading expertise have made it the front runner in supplying performance-enhancing solutions to a variety of problems relating to the production of compliant potable water.

The choice of a proper functioning and safe disinfectant can be confusing, so here are a few frequently asked questions about chlorine dioxide:

Clear 2C Chlorine Dioxide generator

Is chlorine dioxide expensive?

When you compare the cost of your current disinfection regime and the results that it delivers, wouldn’t you pay a bit more to get satisfactory results? In a one-to-one comparison, it may appear to be more expensive; however, if you need five, 10, or 30 times less than your current disinfectant, it clearly becomes the more cost-effective option.

Can I store chlorine dioxide solutions safely?

At a concentration of 2500 to 3000 ppm and packaged correctly, the solution can be stored for several months with little to no change in original concentration, if it has minimal space to off-gas and not subjected to UV radiation.

What are chlorine dioxide’s advantages?

As a disinfection chemical, chlorine dioxide is very effective against bacteria – even more so than chlorine for the disinfection of water that contains viruses.

Over the last couple of years, chlorine dioxide has become more popular, as it is so effective at deactivating the chlorine-resistant pathogens Giardia and Cryptosporidium.

Clear not only removes biofilm but it also ensures a cleaner process, system, and reticulation[CLO2] , as it prevents biofilm from reappearing.

Moreover, another advantage of chlorine dioxide as a disinfectant alternative is that it can destroy phenols that cause odours and taste problems.

Where can I use chlorine dioxide?

Clear can be used in a vast range of applications.

  • Water utilities
  • Food and beverage
  • Abattoirs
  • Farming
  • Hospitals
  • FMCG
  • Hospitality
  • Aviation

Is chlorine dioxide a gas?

Yes, and one of its most important qualities is that it is highly soluble in water. Chlorine dioxide does not hydrolyse when it comes into contact with water; it remains a dissolved gas in solution. It is approximately 10 times more soluble in water than chlorine.

Is chlorine(CL2) and chlorine dioxide (CLO2) the same thing?

Chlorine dioxide is a neutral chlorine compound. It is very different from elemental chlorine, both in its chemical structure and behaviour.

Can chlorine dioxide oxidise manganese?

Though chlorine can be used to control manganese in water[Ci1], it reacts so slowly that there may still be manganese ions left in the water-distribution system even after 24 hours. Chlorine dioxide reacts much more rapidly with manganese, oxidising it to manganese dioxide. Manganese dioxide is insoluble in water and can furthermore be filtered out before the water leaves the treatment plant.

Can chlorine dioxide oxidise iron?

Chlorine dioxide rapidly oxidises Fe2+ to Fe3+, which precipitates as Fe(OH) (iron hydroxide).

How much chlorine dioxide should I dose?

We always recommend performing a demand test, whether it be for potable water, sewage, effluent treatment, or other processes. A demand test will determine how much you would need to dose.

Do you want a disinfectant that works? A solution that yields results? Change to Clear chlorine dioxide as your disinfectant of choice.

Clear CC Chlorine Dioxide generator

Contact us to simplify your life. Our disinfectant strategy promise:

  • Fewer components that can fail;
  • A significant reduction in corrosiveness;
  • Better safety;
  • Ease of use;
  • Remote monitoring;
  • Data logging and referencing; and
  • SMS notifications.

With not a single failed project and a long list of successful chlorine dioxide generator installations, the list of references from our satisfied clients grows daily.

These successful installations include Eskom, British American Tobacco, Virgin Active, SAB AB InBev, Sun International, City of Tshwane, Botswana Water Utilities Corporation, Botswana Meat Corporation, Chubby Chick, Magalies Water, and many more.

You know you cannot go wrong with Clear.

Results wait for no one, so contact us today!

Our projects are coming in at a rapid rate as the difference that we are making on the continent becomes obvious. Don’t delay; schedule a meeting with our experienced staff, explore the chlorine dioxide generator, and to see how we can make a difference for you as well. 

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Sodium Hypochlorite

Dosing with sodium hypochlorite is money down the drain. Find out why.

Have you been looking for a reliable water disinfection solution? A robust treatment regime that gives you the results you are looking for?  At Nanotech, we have the alternative disinfectant to the age-old sodium hypochlorite dosing solution. Our disinfectant is far better at addressing your problems.

We can replace your sodium hypochlorite treatment with a disinfectant solution that really works. In fact, the only reason sodium hypochlorite is so widely available as a disinfectant is because it is a by-product of the main process of producing chlorine gas.

Do you want some by-product like sodium hypochlorite to form the basis of your disinfection regime or a product that was formulated from the outset to be a disinfectant? That is why our award- winning technology in chlorine dioxide is fast becoming the disinfectant of choice.

So many of our clients tell us about their challenges and the prohibitive cost of the chemicals they are currently using – and which are simply not giving them the results they are looking for. Does your disinfectant add value or is it just costing you money? Are you looking for something better? If you could get top results for once at a price that does not break the bank, wouldn’t that be absolutely worth it?

We can offer you alternative, scalable disinfectant solutions that offer you peace of mind. Over many years, Nanotech has positioned itself as the technology leader with a knack for understanding clients’ problems and solving them with an array of advanced technologies. It all comes down to ensuring clients get the results they need.

We have the ideal disinfectant for microbial control and residual challenges covered for clients in all these industries:

  • Water utilities
  • Food and beverage
  • Abattoirs
  • Farming
  • Hospitals
  • FMCG
  • Hospitality
  • Aviation

With our in-depth understanding of which technologies to deploy, combined with our expertise in understanding process requirements, we can resolve your problems and meet all your challenges.

Our sodium hypochlorite alternative can offer you:

  • Improved safety for your employees;
  • Less human intervention;
  • A more autonomous experience;
  • An integrated process;
  • Excellent results; and
  • Lower Hazchem transport costs.
Sodium Hypochlorite Alternative: Front View

Sodium Hypochlorite Alternative: Back View

Doesn’t this sound like just the solution you have been looking for?

We are versed in a vast spectrum of client and process requirements, each requiring the deployment of tailored treatment regimes. We have delivered countless successful projects and brought about cost savings for many of our clients with our alternative to sodium hypochlorite disinfectant solutions.

With every solution we provide, our customers have the peace of mind that their problems are a thing of the past and they can focus on their core business and see it grow. You can contact us for comprehensive reference lists and client testimonials.

Why do people use sodium hypochlorite?

The common misperception is that sodium hypochlorite is an effective disinfectant with a broad range of applications, which is why it is so commonly used in water-treatment systems. On the face of it, it appears to offer the best mix of low cost, ease of use, safety, and efficacy in areas where there is enough water that is not excessively turbid to drink. But this is not accurate.

Why does sodium hypochlorite struggle to maintain a residual?

When sodium hypochlorite dissolves in water, two substances form that both play a role in oxidation and disinfection. These are hypochlorous acid (HOC?) and the less-active hypochlorite ion (OC?-). In potable-water applications with a pH of 7,5 to 8,5, between 50 and 90% of the sodium hypochlorite solution converts to the hypochlorite ion, the less-active component and hence, the one that is relatively poor at maintaining a residual and achieving the results you seek.

Why is Hypochlorite so corrosive?

Because of the high pH of sodium hypochlorite, it attacks metals. It also generates hydrogen gas when coming into contact with aluminium.

Why is Hypochlorite so expensive?

  • As soon as sodium hypochlorite comes into contact with water, it hydrolyses, immediately losing much of its efficacy.
  • It is a non-selective disinfectant and reacts with metals and organics in the water. Therefore, most of it ends up not being used for its intended disinfection purpose, leaving one to dose more and more in order to see results.
  • Sodium hypochlorite can degrade significantly within two to three weeks so, if purchased in bulk, within a month it becomes relatively ineffective and you would have to overdose to get the same residuals as at the initial dosage set points. This is when it becomes an expensive exercise.

Why does Hypo form so many disinfection by-products (DBPs)?

It readily reacts with inorganic and organic materials and forms up to nine different disinfection by-products.

Why do I experience scaling when dosing with Hypochlorite?

The high pH of hypochlorite reacts with calcium and magnesium in diluted water that precipitates as carbonate scale.

Why are my maintenance costs so high when dosing with Hypochlorite?

  • It readily attacks metals and, over a period, you would experience issues throughout your processes and reticulation.
  • Normal glue uses fumed silica (finely ground glass) as thickening. The high pH of the hypochlorite solution can dissolve the silica, leaving the glue joint porous and susceptible to leaks.

Why is it not safe?

  • Mixing anything with hypochlorite can be extremely dangerous. Contact between hypochlorite and other treatment plant chemicals such as alum, iron-based  [Ci1] compounds, or sodium bisulphate can cause an uncontrolled, explosive release of energy, heat, and chlorine gas.
  • Unless flushed, drained, or vented, offline equipment may build up significant pressure from gasification that may be released explosively.
  • Splashes, spills, and leaks may occur. When hypochlorite comes into contact with clothing, it causes bleaching and holes.

You just want something that works, so that you can focus on running your company. At Nanotech, we have the perfect balance of technologies, engineering expertise, support and an understanding of clients’ processes to make a huge difference to your disinfection and water treatment requirements.

Do you have a current disinfection regime?

  • Let us have a look and see how we can improve and enhance the disinfection strategy and get you compliant.

 Battling with poor after-sales service?

  • Nanotech has a dedicated service team and on-call helpdesk staff. We have national representatives at multiple branches if you need assistance.

 Concerned about Hazchem costs?

  • We take your concerns into consideration and provide cost-effective solutions.

Not sure you will get the results?

Let us perform a demand test, demonstrate to get you microbial compliance, and provide you with the residual you need. We can overcome your day-to-day safety issues and give you the desired results. What do you have to lose? We are offering a free audit on any sodium hypochlorite installation for a limited time. Do you want to see how you can get better results? Book a free audit and get Compliant.

Chlorine Gas

Nanotech developed On-Site manufacturing of chlorine gas with liquid pre-cursors as input chemicals, efficient, reliable and SAFE.

Chlorine gas is mass-produced from established industrial processes. It’s stored in high-pressure vessels ranging from typically 70 kg to 990 kg of chlorine in containers. The chlorine gas is in a liquid form inside these pressure vessels and is transported all over the continent on Hazchem delivery vehicles.


The transporting and handling of the cylinders is inherently dangerous as these are manhandled. Therefore, Incidents are recorded continuously. Leakages of these pressure vessels can cause a significant number of deaths and subsequently extensive and permanent harm to mankind.

Therefore, The equipment designed and used to convert the chlorine liquid to a gas phase needs to be inspected regularly and should be well maintained to prevent any spillages and leakages.

The capital costs for installation are significant if all safety regulations are adhered to. For example, well-ventilated buildings, extraction fans, scrubber systems, and good quality warning devices that shut off the supply of the liquid or gas chlorine to the environment or process.

As a result, In most cases, the condition, quality and safety issues are not up to minimum safety standards due to lack of regular maintenance and lack of experienced personnel to manage these installations.

The most significant safety factor in these installations is the inventory of chlorine gas, liquid or gas on site. When something goes wrong, this inventory will escape into the environment. consequently, cause huge harm to everyone and everything in its way, subsequently  KILLING all living species.

The “On-Site” chlorine manufacturing idea was born to address significant risks associated with chlorine gas and the stringent legislation of SANS 10298:2009

About On-Site Manufacturing

On-Site manufacturing of chlorine gas with liquid pre-cursors as input chemicals, efficient, reliable and SAFE.

Therefore, The “On-Site” manufacturing idea was born to address significant risks associated with chlorine gas and the stringent legislation of SANS 10298:2009

Unique benefits of the technology:

  • Compact design
  • Modular systems
  • Two Chemical System
  • Auto Control System
  • Ph Control
  • Flow Control
  • Free chlorine measurement and control
  • Remote Login Facility
  • Gas Leaking device optional
  • Technology Support
  • SLA Agreement

Process description of Technology

The technology is a chemical process. Two pre-cursors are mixed in a predefined ratio and fed into a chemical reactor chamber for the reactions to take place. These two pre-cursors are Hydrochloric Acid (HCl) and Sodium Chlorate (NaClO3).

The chemical reactions are that of the oxidation and reduction of the pre-cursors. Therefore, The sodium chlorate is reduced to chlorine and the hydrochloric acid is oxidised to chlorine.

When chlorine output is required, the basic chemical formula is the following:

NaCLO3 + 6HCL = 3CL2 + NaCL + 3H20

This concentration is diluted with water to a safe level.

When chlorine and chlorine dioxide output is required the basic chemical formula is the following: 

2NaClO3 + 4HCl = 2ClO2 + Cl2 + 2NaCl +2H20


Firstly, The main advantage of this technology is the on-site manufacturing of chlorine gas dissolved in water and then used in the process for disinfection. In addition, The pre-cursors are hydrochloric acid and sodium chlorate which are injected into a chemical reactor chamber. This produces a final concentration of chlorine of 2000 to 3000 ppm in water.

Secondly, Added to this technology package, the process water pH will be controlled within a pre-determined range of typically 6.0 -7.5, to maximise the full disinfection potential of disinfectant, on-site chlorine generation.

Finally, the SLA agreement will take care of the maintenance of the system and components, delivery and stock management of pre-cursor chemicals and consistent final product delivery (chlorine) with minimum process availability of 98%.

Chlorine Gas on-site Manufacturing Technology

Ag-R Disinfection Technology

No chlorine. No-Risk. No Red eyes. No irritated skin. No handling of chemicals. Just RESULTS!

The “passive” Disinfection Technology killing microorganisms [Ci1] effectively.

Media-filtration systems are designed to filter out suspended solids and debris from closed water systems. These are typically swimming pools, evaporative-cooling towers, or side-stream filtration systems. These filter systems are usually not designed to facilitate a high enough backwash volume to lift the media, to maximise backwash efficiency, or to remove the filtered mass.

Over time, this leads to massive contamination and recontamination of the bulk-water system. The filtered mass that gets stuck inside the filtration media over time becomes toxic and this media needs to be replaced frequently to maintain filtration efficiencies. The same applies to carbon filtration columns where organic removal is required; however, large-scale bacterial activity inhibits efficient removal.

The main challenge is the disinfection of these vessels and to treat the bacterial contamination and recontamination of a system without resorting to aggressive chemical treatment.

The disinfection solution is to maintain sterility inside the vessel and effectively have a “killing zone” during the process inside the filtration media. The target is to achieve a disinfection target of 2- to 4-log reduction in bacterial and viral activity inside the vessel and to significantly extend the life of the filtration media and minimise the risk of contamination.

There are only two reliable methods and chemistries recommended for effective disinfection, especially for Legionella, in these recirculation systems. One is chlorine dioxide (CLO2) and the other is silver (Ag). These disinfection technologies are recognised internationally as the most effective disinfection technologies to kill the notorious and challenging Legionella.

There are two ways to apply these disinfection technologies:

  1. Chlorine dioxide in solution, with continuous injection while in operation, or elevated levels of chlorine dioxide in the backwash process.
  2. Silver ions in contact with the bacteria and viruses for effective disinfection, while at the same time preserving this extremely expensive commodity.

Nanotech developed the technology using silver by coating an ion-exchange resin with silver ions and then combining it with a very efficient filtration media, namely zeolite, to effectively kill the bacteria and filter the debris during the disinfection process. The resin beads, which are between 0,8 to 1,4 mm in diameter, are coated with a layer of silver ions at an ionic level which, when the silver  comes into surface contact with bacteria and viruses, immediately starts the killing and log-reduction processes. These silver-coated resin beads are typically mixed at a concentration of between 10 to 20% by volume (process dependent) with the filtration media. This media vessel allows for a residence time to ensure an efficient CT value.

It is important for effective disinfection to position the Ag-R mixed media of zeolite and silver-coated resin beads after the main filtration system. The first filtration vessel is the first line of filtration to clean up the water and backwash it when maximum delta pressures are reached. Only then will this technology primarily act as the disinfection step. The Nanotech Ag-R disinfection vessel is only backwashed when required. In this slow backwash process, the debris and dead bacteria are removed and pumped away.

Nanotech’s offering includes the validation and confirmation of correctly designed primary filtration vessels and their efficiency. This Nanotech Ag-R disinfection technology is then sized for a specific residence time to allow for desired contact time and log reduction.

What makes this disinfection technology and application unique?

  • No chlorine or chemicals added.
  • No handling of dangerous chemicals.
  • No burning of skin or eyes.
  • No overdosing.
  • No by-product formation.
  • No bleaching of hair or skin irritation.
  • The process can be automated.
  • Solves a challenging problem.

Contact Nanotech to get this technology installed and evaluated for your peace of mind. Get access to technology that really works, while you enjoy the benefits it provides.

Go the Nanotech Ag-R way!

Sewage Treatment

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Sewage Treatment Plants 100% Compliance

How much is non-compliance of your sewage treatment plant costing you?

Here is what you shouldn’t be paying for:

  • Fines for legal non-compliance.
  • Lawsuits from individuals made ill by improperly treated sewage.
  • Lawsuits from environmental and conservation groups.
  • Absenteeism of sick employees.
  • Boycotts of your products.
  • Lost revenue due to environmentally legal stop-work orders.

The cost of non-compliance is far greater than that of a quality sewage treatment system.

Sewage treatment SAFF technology

The law requires that all sewage be treated

  • Water is a precious resource. Wildlife and fisheries depend on sufficient water. By law, all sewage must be treated.
  • You want to be a good corporate citizen. Your brand suffers when people complain about the smell from your sewage treatment operation.
  • Health and safety. If your employees and the people that live near your operations get sick, you do not only suffer reputational damage, but you can be liable for huge fines and levies if your sewage is not treated in compliance with regulations.

The law requires it! Non-compliance costs much more than our sewage treatment systems.

What is sewage treatment compliance?

Compliance is the ability to consistently achieve results aligned with the requirements of the government, your clients, and the community.

When you work with Nanotech, compliance takes on a bigger meaning:

  • Compliance with reliability standards – your sewage treatment system will be reliable in operation, with maximised uptime and maintained outlet compliance.
  • Compliance with maintainability standards – your system will be assembled from equipment that is easily maintained, with readily available spare parts.
  • Compliance with quality standards – as a company working in compliance with ISO 9001-2015, Nanotech ensures that your system will comply with fabrication and operational quality requirements. Your sewage treatment system is a capital expense and our adherence to the relevant standards ensures that it will achieve its design life and be money well spent.
  • Compliance with ease of operations – your system will be easy to operate, so that your operators can spend their time working instead of managing your sewage treatment system.

We define compliance the way you need it to be!

Can a septic tank produce compliant effluent? No, it cannot.

Many institutions use only a septic tank to treat their sewage but that does not produce compliant effluent. Compliant effluent requires significant reductions in organic contaminants measured by chemical oxygen demand (COD) and biological oxygen demand (BOD).

It also requires significant reductions in nutrients like ammonia (NH3), nitrates (NO3), and phosphates (PO4).

A septic tank on its own cannot achieve compliance with the specifications.

Can you upgrade your septic tank to be compliant? Yes, you can!

If your business produces sewage and you are currently only treating it with a septic tank, there is a solution.

Our packaged sewage treatment systems include a septic tank as one of the several steps needed to produce compliant effluent. We can add our package system to your upgraded septic tank, bringing your system into compliance.

Septic tank view for wastewater plant

How do you need to treat your sewage to comply with the law?

In short, the specifications require a reduction in chemical oxygen demand (COD) and biological oxygen demand (BOD), total suspended solids (TSS), and nutrients like ammonia (NH3), nitrates (NO3), and phosphates (PO4).

Our turnkey packaged sewage treatment systems are based on the preferred technology known as a submerged aerated fixed film (SAFF) system. This uses an attached growth process consisting of:

  1. Initial screening via a septic tank where large solids are separated from the liquid.
  2. Carbon removal and nitrification performed in the recycle tank and SAFF unit.
  3. Smaller solids removed in the secondary settlement tank.
  4. Chlorination is the final step, where the effluent is disinfected.

We supply SAFF units because:

  • They are easy to operate, requiring little operator intervention.
  • They use less power than other methods.
  • They offer consistent effluent quality.
  • They produce very little sludge, and
  • They are extremely well suited to remote operations.

Why is activated-sludge (AS) technology NOT ideal for packaged sewage treatment units?

While some companies may use activated sludge instead of SAFF, it requires far more energy, produces a lot more sludge, and requires constant operator attention. That’s why Nanotech chose SAFF as the preferred technology for our packaged sewage treatment plants.

SAFF is a more efficient solution.

SAFF gives a 95% reduction in BOD/COD and a 60% energy saving over AS plants.

The SAFF sewage treatment system is a biological treatment process using a submerged aerated biofilter with attached growth process. The high-rate biological oxidation process is performed using an extremely efficient SAFF with a very high specific surface area. The SAFF sewage treatment plant can deliver a final effluent that is low in COD/BOD, total suspended solids, ammonia, nitrogen, and phosphates.

Sewage Treatment Plant
Control room for sewage plant

The most typical applications of Nanotech’s Compliance SAFF sewage plants

The market requires a robust, reliable, and easy-to-operate solution. Our SAFF units are ideally suited to the following applications:

  • Hospitals
  • Schools
  • Shopping centres
  • Hotels and holiday resorts
  • Mining camps
  • Hostels
  • Lodges

Our SAFF sewage treatment units do not require skilled personnel. Typically, only one operator is required to do checks during the day.

Our SAFF technology is, without a doubt, the best solution for your sewage treatment needs.

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Settler and disinfection view