Application of cleaner production technology in chemical industry: a near zero emission

The main objective of this study is to investigate and evaluate opportunities for implementation of pollution prevention and waste minimization in a chemical industrial company producing poly sulfonated naphthalene formaldehyde which is used as a super plasticizer for concrete. Environmental problems encountered were mainly the highly polluted wastewater and a semi-solid cake containing considerable amount of the final product. Possible modules for remedial measures and their cost estimation were investigated. The proposed remedial modules included recycling of retained water discharge in filter press, recycling of washing water of reaction vessels (reactors), closed circuit cooling system for high-pressure pump, good housekeeping through control of leakage of raw material, products and water and finally utilization of retained residual product from the solid waste. The implemented pollution control measures proved to be cost effective and have short payback periods. Also, minimization of the hydraulic and organic loads in the final effluent was achieved.