城市污水处理过程中微塑料赋存特征

Occurrence, characteristics of microplastic during urban sewage treatment process

以上海某污水厂为例,研究了中国沿海城市污水厂进出水、污泥中微塑料的赋存特征及微塑料排放量.结果表明,污水厂进出水中微塑料形态主要为纤维状.进水含量最高的种类依次为人造丝(36.84%)、合成革(21.05%)和聚酯纤维(18.42%),出水中的种类依次为合成革(26.67%)、人造丝(24.44%)、聚酯纤维(17.78%)和聚乙烯(15.56%).微塑料在总进水中的丰度为117n/L(n为微塑料个数),调配水中为90n/L,总出水中为52n/L,污泥中为180n/50g(湿重).该污水厂日出水量为280万m^3/d,据此估算微塑料量由总进水中3276亿n/d降至总出水中1456亿n/d,去除率为55.6%.污水厂根据实际进水水质确定剩余污泥量150t DS/d,含有5.4亿个微塑料.此外,根据本研究结果讨论了有关国际刊物中对我国大陆范围内个人护理用品中微塑料入海量的不准确估算.

By extracting microplastics（MPs）in the water and sludge samples,the occurrence of MPs in a coastal municipal sewage plant in Shanghai was studied.This study firstly investigated the characteristics and emissions of MPs in the coastal WWTP of China.Fiber was the most common shape.Rayon was the most common polymer type in the influents.In the effluents,synthetic leather accounted for the largest porpotion followed by rayon,polyester and polyethylene.The abundances of MPs in the influents,mixed water,effluent and sludge stages were 117n/L,90n/L,52n/L and 180n/50g（wet weight）,respectively.The removal efficiency of microplastics in the WWTP was 55.6%.Cursory calculations estimated the abundance of MPs in the waters decrease from 3.276 trillion in the influents to 1.456 trillion in the effluents,and the excess sludge contain approximately 54million MPs.Moreover,a miscalculation of personal care product MP discharge from the China's Mainland to the ocean was also be discussed.