Chlorine Dioxide - Disinfectant - Disinfection

Chlorine dioxide

Chlorine dioxide (CLO2) is both an oxidant and disinfectant for drinking and industrial water and widely accepted as the preferred alternative to chlorination. Chlorine dioxide is stable and highly soluble in aqueous solutions up to 20 g/l. In addition to its biocidal properties, chlorine dioxide improves the quality of drinking water i.e. odour neutralisation, colour removal, iron and manganese oxidation and a very effective biocidal efficacy over a pH range between 3 and 9.

Chlorine dioxide is ultraviolet light sensitive and exhibits increasing oxidative capacity with increasing acidity. Chlorine dioxide is used in many industrial water treatment applications as a biocide, including cooling towers, process water and food processing.

Chlorine dioxide is a stronger disinfectant than chlorine and chloramine. Ozone has greater microbiocidal effects, but limited residual disinfection. ClO2is more effective than chlorine against viruses, bacteria and protozoa including the cysts of Giardia and the oocysts of Cryptosporidium as an oxidant for phenol destruction in waste water streams and for odour control in the air scrubbers of animal byproduct plants.

Chlorine dioxide exists in the water as CLO2 (little or no dissociation) and thus is able to permeate through bacterial cell membranes and destroy bacterial cells. Its action on viruses involves adsorbing onto and penetrating the protein coat of the viral capsid and reacting with the viral DNA. As a result, the genetic capability of the virus is damaged. In comparison to chlorine, chlorine dioxide can be more effective as a disinfectant due to the fact that chlorine exists in the water as HOCL or OCL. As a result, bacterial cell walls are negatively charged and repel these compounds, leading to less penetration and absorption of the disinfectant into the membranes.

The Nanotech chlorine dioxide range of generators produces chlorine free ClO2 at high efficiency by reducing sodium chlorate in a strong solution of sulphuric acid as the reducing agent in the presence of hydrogen peroxide.

The chemical reaction of sodium chlorate reduction with sulphuric acid:

2NaCLO3 + H2O2 + H2SO4 reacts to form 2CLO2 + O2 + 2H2O + Na2SO4

For a free consultation, please contact Jakes on jakesj@nano-tech.co.za , or phone 083 570 8267

Applications:

Chlorine dioxides safety features and versatility make it ideal for a spectrum of applications, including healthcare and hospital facilities, food and beverage processing, ultra pure water treatment, Legionella control, cooling towers and loops, water hygiene, potable water treatment, wastewater treatment, residential, commercial and industrial facilities.

Control of THMs
Cooling water treatment
Cyanide destruction
Iron and manganese oxidation
Legionella control
Organic odour control
Phenol destruction
Potable water disinfection
Sulphide odour control
Taste and odour control
Treatment of biofilms
Treating industrial plant water
Wastewater disinfection

Nanotechs chlorine dioxide generators are unique for the following reasons:

Generators ranging from 100 to 1500 g/hr.
Safe production of CIO2.
Eco-friendly biocide.
Cost-effective, highly potent biocide.
Simple and easy to use generating system.
Generates 25% more CIO2 than traditional methods.
Point of use generation, on demand.
Chlorine free CIO2.
Excellent alternative to bleach, ozone and bromine.
No hypochlorite or chlorine gas required.
Not pH dependant.
No pipe corrosion.
Not generating harmful byproducts

Chlorine dioxide is an extremely reactive gas, which because of its instability cannot be stored, and must only be produced in the required quantities in special plants on the site where it is to be used. Chlorine dioxide offers a number of advantages for water disinfection compared with chlorine, the disinfectant mainly used. The disinfecting power of chlorine dioxide actually increases slightly with increasing pH, whereas with chlorine the disinfecting power reduces. Chlorine dioxide remains stable in the pipeline system over a long period and ensures microbiological protection of the water for many hours, or even several days. Ammonia and ammonium, which cause significant chlorine depletion, are not attacked by chlorine dioxide, so that the dosed chlorine dioxide is fully available for bactericidal action. Chlorophenols, compounds with intense odours, which can be produced during water chlorination in some circumstances, are not formed when chlorine dioxide is used. Trihalomethanes (THMs), a group of substances, which, like their best known example, chloroform, are suspected of being carcinogenic, are produced when chlorine reacts with natural water components (humic acids, fulvic acids, etc.). Measured THM concentrations, if present at all, are drastically reduced when chlorine dioxide is used as an alternative disinfectant.

Advantages of chlorine dioxide:

Disinfection power is independent of pH.
High residual effect thanks to long-term stability in the pipeline system.
Reduction of the biofilm in pipelines and tanks, hence reliable protection of entire water systems against legionella contamination.
No reaction with ammonia or ammonium.
No formation of chorophenols and other intense odour compounds which can be produced in water chlorination.
No formation of THMs and other chlorinated hydrocarbons, no increase in the AOX value.

For every new project, our engineers draw on experience accumulated since 1976, in the following applications:

Municipal drinking water and wastewater plants

Disinfection of drinking water
Disinfection of wastewater

Hotels, hospitals, retirement homes, sports facilities, etc.

Combating legionella in cold and hot water systems
Water disinfection in air conditioning system cooling towers

Food and beverage industry

Disinfection of product and service water
Bottle cleaning, rinser and pasteuriser
Cold sterile bottling
Disinfectant in CIP systems
Condenser water treatment (condensate) in the milk industry
Disinfection of wash water for fruit, vegetables, seafood, fish and poultry

Horticulture

Disinfection of irrigation water used in plant growing

Industry

Cooling water treatment
Combating legionella in cooling circuits
Disinfection of process water
Removal of odorous substances in air scrubbers
Combating slime in the paper industry

For a free consultation, please contact Jakes on jakesj@nano-tech.co.za , or phone 083 570 8267