Geng Jinju

A review of membrane fouling in municipal secondary effluent reclamation

Reclamation of municipal secondary effluent for non-potable purposes is considered vital in alleviating the demand for existing limited water supplies while helping to protect remaining water sources from being polluted. In recent decades, reverse osmosis and nanofiltration membrane technologies have become increasingly attractive for reclamation of municipal secondary effluent because they are highly efficient, easy to operate, and economical. However, membrane fouling is a major obstacle in the development of membrane technology in municipal secondary effluent reclamation. This paper reviews three types of membrane fouling in municipal secondary effluent reclamation, namely, effluent organic matter (EfOM) membrane fouling, microbial membrane fouling, and inorganic membrane fouling, as well as their correlation. Membrane fouling by EfOM and microbes are found to be severe, and they are significantly correlated. Most previous studies conducted laboratory-scale experiments of membrane fouling with model organic matters and bacteria, but these model organic matters and bacteria might still be unrepresentative. More studies on membrane fouling in municipal secondary effluent reclamation with actual wastewater are essential.

Speciation of Cd and its relationship with the bioaccumulation of Corbicula fluminea in the sediments of Lake Taihu

A simulated experiment exposing Corbicula fluminea in the Cd contaminated sediment of Lake Taihu was conducted in laboratory to study the bioaccumulation of Cd in Corbicula fluminea and the distribution regularity of Cd in water.The speciation of Cd extracted by DGT and BCR and the releasing regularities were determined in sediments of Lake Taihu to obtain the applicability of predicting sediment quality guidelines.When the contaminated concentration increased,the concentration of Cd extracted by DGT and BCR in overlying water and accumulated in Corbicula fluminea increased.The results showed that the content of Cd in Corbicula fluminea was significantly correlated with the results measured by two methods after 14 days and 28 days exposure.It offered theoretical statistics for the prediction of sediment quality guidelines of Cd.