Chemviron offers an array of purification solutions for municipal drinking water– all delivered through a comprehensive global service network.
These can be used independently or in combination to meet your needs and/or regulatory standards in the most economical way possible.
Municipal and Industrial Drinking Water
Chemviron is the largest supplier of granular activated carbon to the water industry and was a pioneer in the development of its use in Europe. The FILTRASORB®range of carbons have been installed in municipal water treatment works for over 30 years, with over 220,000m3 installed at over 1,000 sites globally.
Drinking Water Treatment
The Calgon Carbon group, including Chemviron in Europe, is a leading supplier of activated carbons to the global drinking water industry, supplying in excess of 100,000 m3 of material per year for this important application.
Granular Activated Carbon in Potable Water Production
Granular Activated Carbon can be used in rapid gravity filters, Slow Sand Sandwich filters and mobile and fixed pressure rated adsorbers.
Today, Granular Activated Carbon is the standard for the treatment of surface sourced drinking water and contaminated ground water in Europe. GAC will improve the quality of drinking water by removing:
- Taste and odour forming compounds (compounds such as MIB and geosmin)
- Pesticides including byproducts (e.g. atrazine)
- Trihalomethanes and other disinfection byproducts (DBP removal)
- Algal toxins
- Chlorinated hydrocarbons and other volatile organic compounds (VOC removal)
- Endocrine distrupting compounds (EDC removal) and other micropollutants
- Pharmaceutical and personal care products (PPCP removal)
GAC for drinking water treatment needs a pore structure to allow the adsorption of a wide range of organic compounds including specific micro-pollutants and natural organic matter. The GAC must also possess a suitable amount of transport pores which allow the molecules to be transported to the adsorption sites. The adsorption capacity for drinking water applications is very difficult to quantify by laboratory evaluation. Parameters such as the iodine number indicate the overall porosity of the carbon, but cannot be used to estimate the performance in drinking water applications. This is illustrated by the fact that FILTRASORB® 200 has a higher capacity than FILTRASORB® 400 for the removal of chlorinated compounds from ground water, even though it is less active. The best way to evaluate the performance of GAC is to carry out on-site pilot tests directly modelling the proposed plant. Alternatively, the design should be based on experience and references.
The pore structure of carbon is strongly influenced by the raw material and the activation process. For example, coconut shell-based activated carbons have very few transport pores. This means the high adsorption capacity of these activated carbons is not utilised very well in drinking water. In contrast, the Chemviron FILTRASORB® range of coal-based GAC have a very good balance of both adsorption and transport pores, making them optimal for the treatment of drinking water.
FILTRASORB® 200 has an adsorption capacity suited to the removal of specific organic compounds in the presence of low concentrations of natural organic matter. In addition, this product is suitable for taste and odour removal.
FILTRASORB® 300, 400 and TL830 have a pore structure and greater number of transport pores making the GAC suitable for the adsorption of a wide range of organic compounds, both specific micro-pollutants and natural organic matter.
FILTRASORB® type carbons have a high density, which means a higher capacity per unit volume. This also ensures the granules do not float and therefore minimises the filter/service loss of GAC.GAC in drinking water requires high mechanical strength for:
- Air scouring
- Handling and transport
If the carbon is not strong enough, it can result in operating losses and the formation of fine carbon particles in the adsorber which can cause high pressure drop. The hard coal base of FILTRASORB® carbons ensures good mechanical strength and, in general, the operating losses from a well designed adsorber are negligible.
FILTRASORB® is a renowned range of granular activated carbons, which are installed in over 1,000 water treatment plants in Europe, the United States and Asia.
FILTRASORB® carbons are produced by steam activation of selected grades of bituminous coal that have first been pulverised then agglomerated.
Chemviron has been at the forefront of the development of GAC for drinking water treatment from its first application as a sand replacement for taste and odour removal to more recent developments such as the GAC Sandwich for the installation of GAC in slow sand filters. In addition, Chemviron has pioneered the use of large scale reactivation centres to provide a complete service for water works. Once granular carbon is saturated or the treatment objective is reached, it can be recycled, by thermal reactivation, for return and reuse in the original water works.
PAC in Potable Water Production
Powder activated carbon (PAC) is used in potable water production for seasonal or short to medium term problem solving. Chemviron has developed a range of products, under the PULSORB® brand, which are similar in adsorption characteristics as the FILTRASORB® granular carbon range. These powders are made from bituminous coal and are available in big bags, sacks or in bulk.
The recent application of powdered activated carbon in combination with ultrafiltrationmembranes has become an alternative and effective technology for the removal of organic compounds in drinking water. Chemviron has developed products with specific characteristics for this type of application.
Home water treatment
Chemviron supply special silver impregnated coal and coconut carbons for Point of Use (POU) and Point of Entry (POE) water filters. The silver impregnation provides a safe and effective method of controlling/preventing bacterial growth.
AQUACARB AGC products are high quality silver impregnated activated carbons for use in specialist water treatment applications, which require their proven bacteriostatic properties. They are manufactured from specific high purity grades of coconut shell and impregnated with silver using a unique process developed by Chemviron. This method produces a high quality activated carbon that inhibits the growth of bacteria on the carbon surface. The levels of impregnated silver in AQUACARB AGC have been optimised to provide maximum bacteriostatic protection, and because of this the frequency of sterilisation of deep bed filters is reduced or eliminated.
AQUACARB AGC is ideal for use in point of use (POU), domestic jug and tap filters, where the build-up of bacteria must be prevented. It is also employed in soft drink bottling plants, breweries and the food industry, for similar reasons.
Users of AQUACARB AGC will experience low controlled levels of silver leach into the water because of the unique manufacturing process that Chemviron utilises, which chemically fixes the silver to the carbon. Thus silver leach levels are far lower than US EPA Drinking Water Standards but sufficient to provide maximum bacteriostatic action with extended product life cycle.