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

摘要： 壳聚糖作为天然的高分子絮凝剂，其来源广泛、安全环保、可生物降解、环境友好。由于壳聚糖水溶性差，需要溶解于一定的稀酸才能使用，增加了操作程序和应用成本。本文将壳聚糖改性为羧甲基壳聚糖，使其具备水溶性。壳聚糖改性后得到可溶于水的羧甲基壳聚糖（CMC），将其与聚合氯化铝（PAC）进行复配，处理长庆油田某采气厂含醇污水，通过透光率来考察CMC-PAC复配絮凝剂对污水的处理效果。实验表明，羧甲基壳聚糖与聚合氯化铝投加量比为1∶7，反应温度为70℃，反应时间为2.5h，含醇污水透光率可达98.7%。与单独投加PAC和CMC相比，含醇污水透光率分别提高13.6%和12.3%。CMC-PAC复配絮凝剂通过吸附电中和、吸附架桥、双电层压缩、网捕等作用在含醇污水中起到了良好的絮凝效果。

关键词: 含醇污水, 羧甲基壳聚糖, 聚合氯化铝, 复配絮凝剂