关键词: 含醇污水, 羧甲基壳聚糖, 聚合氯化铝, 复配絮凝剂

Abstract: Chitosan, as a natural polymer flocculant, is a well-sourced, safe, environmentally friendly, biodegradable and eco-friendly material. Due to poor solubility in water, chitosan needs to be dissolved in dilute acid, which increases operating procedures and application costs. In this paper, chitosan was modified to carboxymethyl chitosan to make it water-soluble. The carboxymethyl chitosan (CMC) was mixed with poly aluminum chloride (PAC) to treat the alcohol wastewater in a gas production plant of Changqing Oilfield. Transmittance was used to evaluate the effect of wastewater treatment with CMC-PAC complex flocculant. The experiment shows that as dosage ratio of carboxymethyl chitosan and poly aluminum chloride is 1:7, the reaction temperature is 70℃, the reaction time is 2.5h, the transmittance of alcohol containing wastewater can reach 98.7%. As compared with PAC and CMC alone, the transmittance of wastewater treated by CMC-PAC increase by 13.6% and 12.3% respectively. CMC-PAC composite flocculant played a good flocculating effect in alcohol containing wastewater by adsorption neutralization, adsorption and bridging, double electric layer compression and net capture.

Key words: alcohol wastewater, carboxymethyl chitosan, polyaluminum chloride, complex flocculant