Pulse-Chlorination®, the Best Available Technique in Macrofouling Mitigation Using Chlorine
In 1998, KEMA developed a new chlorination method called Pulse-Chlorination®. It enables optimal antifouling treatment with a minimum use of chlorine. This technology is based on the principle that in general mussels and clams have a re-covery period after exposure to chlorination before opening fully and restarting filtration. The method takes advantage of this recovery time by using short successive periods of chlorination, alternating with periods without chlorine. The tests undertaken between 1998 and 2001 resulted in chlo-rine savings up to 50% on a yearly basis, compared to re-gimes applied in earlier years. Results on site after one year with Pulse-Chlorination® show improved control of macro-fouling and a better overall performance of the cooling water system. This in turn allows longer intervals between planned outages, thus spreading the running costs over three years rather than two years. There are additional advantages for power plants that use electrochlorination plants to produce hypochlorite. As the Pulse-Chlorination® reduces the hy-pochlorite dosage up to 50%, only part of the installed equipment is used at any one time allowing maintenance of the unused electrochlorination plants. Because less hy-pochlorite is dosed, there is a reduction in chlorination by-products discharged and thus less environmental impact.