丙烯腈生产废水的组成对膜吸收去除氰化物的影响

Influence of Acrylonitrile Wastewater Composition on Cyanide Removal by Gas Filled Membrane Absorption (GFMA)

以吉林某石化公司的实际丙烯腈生产废水为研究对象,考察了丙烯腈生产废水的组成对膜吸收去除氰化物的影响.结果表明:丙烯腈生产废水中的氰化物基本为易释放的氰化物,共存的挥发性丙烯腈对膜吸收法去除氰化物的影响可以忽略不计;废水中的丙酮氰醇对膜吸收法去除氰化物的影响最大.丙烯腈废水采用膜吸收除氨-除氰工艺,由于碱性环境以及适当的加热,促进了丙酮氰醇分解转化为HCN,氰化物的去除率可以从40%～70%提高到82%～90%,同时氨氮的去除率达到93.3%以上.气态膜吸收法能够有效去除并回收丙烯腈废水中的氨氮和氰化物,有效降低后续处理负荷,并为后续生物处理提供可能的条件.

The influence of wastewater composition on the cyanide removal efficiency by a promising treatment method called gas filled membrane absorption （GFMA） was investigated in this study using real acrylonitrile wastewater, which was produced from Jilin Petrochemical Industry Company. The results showed that the cyanide in the acrylonitrile wastewater mainly existed as free cyanide. The volatile acrylonitrile coexisting in the effluent had little effect on the cyanide removal by GFMA. However, high concentrations of acetone cyanhydrin had great influence on the cyanide removal efficiency. If GFMA were applied to aerylonitrile wastewater treatment successively in the sequence of ammonia and cyanide removal, the cyanide removal efficiency could increase from 40% -70% to 82% - 90% due to the heating and alkali aqueous solutions, which benefit acetone eyanhydrin decomposition to volatile HCN. In the meantime, the ammonia removal rate ~ould reach as high as 93.3% in the same process. In conclusion, GFMA can remove and recover the ammonia and cyanide from acrylonitrile wastewater effectively, which benefits the subsequent treatments and makes biological treatment possible.