Engineers at the University of Calcutta have found that flyash is an excellent catalyst for treating toxic and non-biodegradable chemicals in effluents from the pesticide industry. The results are based on the fact that flyash is nothing but a mixture of oxides. Almost half of its contents are silica or oxide, yet another time-tested catalyst. The effluents are loaded with organic chemicals which are removed during treatment by chemical oxidation as they are non-biodegradable. The choice of the oxidising agent used for this purpose is hydrogen peroxide.