MEP releases the Emission Standard of Pollutants for Caustic Alkali Industry

It was learned that the new standards raise control requirements for air pollutant emission, adjust water pollution discharge control projects, tighten related control requirements, and cancel the provisions for level-to-level administration based on sewage directions. Upon the implementation of new standards, it is predicted that the chemical oxygen demands (COD) of waste water and five-days biochemistry, as well as emissions of total mercury and chloroethylene will be cut by 77%, 67%, 67% and 87% respectively compared with the implementation of existing standards; in comparison with the implementation of existing standards, the emissions of exhaust particulates, chloroethylene and non-methane hydrocarbon (NMHC) will be cut by 51%, 72% and 58% respectively. 

Compared with the old standards issued in 1995, new discharge standards have multiple significant revisions: increasing control requirements for air pollutant emission, including ten pollutant projects, such as particulates, sulfur dioxide, nitric oxide, chlorine, hydrogen chloride, mercury and compounds thereof, chloroethylene, dichloroethane, non-methane hydrocarbon and dioxin in total; increasing 14 water resource pollutant projects, such as petroleum, ammonia nitrogen, total nitrogen, total phosphorus, total barium and total nickel; further tightening the water pollutant discharge control requirements, such as five-day BOD, suspended matter, active chlorine, chloroethylene, total mercury and benchmark displacement; improving special discharge limiting values of water and air pollutants; canceling the provisions for level-to-level administration based on sewage directions. 

According to Zou Shoumin’s presentations, the conventional pollutant discharge limiting value of waste water in the new standard is at the middle or relatively strict level in comparison with the international standards. With regard to air pollutant discharge, the discharge limiting values of mercury and compounds thereof are stricter than the relevant provisions made by Germany and the World Bank, the limiting value of chloroethylene is wider than that made by the US and The World Bank, the limiting value of dichloroethane comply with the relevant provisions made by the World Bank, and the limiting value of TCDD is in consistent with the provisions made by EU and the World Bank. In general, the standards are not low. The implementation of new standards can greatly cut down the pollution caused by particulates in the chlor-alkali industry, nitrogen oxides, sulfur dioxide, especially mercury. As a result, introduction of enterprise to make technological progress will result in industrial transformation and upgrading. 

Zhang Wenlei, Vice President and Secretary General of China Chlor-Alkali Industry Association, pointed out that the promotion of emission on standard and green development in the chlor-alkali industry depends on scientific and technological innovation and progress of technical equipment. For the purpose of enhancing popularization and application of membrane polar distance ion membrane electrolysis bath, domestic ion exchange membrane and low mercury catalyst, it is proposed to further accelerate research on mercury-free catalyst, build industrial demonstration projects for acetylene and dichloroethane mercury-free processes, strongly promote development and application of oxygen cathode technology of ion membrane electrolysis bath for caustic soda, novel chlorine preparation process, improve clean production level, and advance energy and water resource use efficiencies, in order to reduce pollutant discharge at the source.