Preparation of a PASi-P(AM-ADB) hybrid flocculant and efficiently removal bio-refractory organics from coking wastewater

Abstract

Bio-refractory organic contaminants (BOC) originating from coking wastewater is a severe threat to the environment and human health. The efficient pretreatment of coking wastewater is necessary to decrease the stress of the biological treatment stage. For pretreatment, the development of effective flocculants is needed. In this work, a novel inorganic–organic hybrid flocculant, polyaluminum silicate chloride–polyacrylamide–acryloyloxyethyl dimethylbenzyl ammonium chloride (PASi-P(AM-ADB)), was prepared and its flocculation behavior for raw coking wastewater were investigated. Flocculation results showed that this hybrid flocculant exhibited significantly higher removal efficiency than two other common flocculants, polyaluminum chloride and cationic polyacrylamide. Gratifyingly, the PASi-P(AM-ADB) can also efficiently remove refractory organic contaminants during the process of flocculation, as demonstrated by gas chromatography–mass spectrometry (GC–MS). Particularly, several polycyclic aromatic hydrocarbons, defined as persistent organic pollutants, are removed completely. Here, we demonstrated that this new hybrid flocculant presented outstanding flocculation properties as well as high-efficient removal of some special BOC from raw coking wastewater. This work might provide new insights into the design of functional inorganic–organic hybrid flocculants and enhance the treatment of complex industrial wastewater.