高温季节深度处理水厂二氧化碳控铝研究

Carbon Dioxide for Aluminum Control in Water Treatment Plant with Advanced Treatment Process in High Temperature Season

高温季节原水中藻类大量繁殖,导致其pH升高,对水厂出水的铝控制带来了挑战。惠南水厂新建了44×10^(4)m^(3)/d的二氧化碳调节pH工艺,在2022年8月开展了二氧化碳控铝试验,并对全过程水质进行分析。结果表明:以青草沙水库为水源的臭氧/生物活性炭工艺水厂在原水水温超过29℃的高温季节,通过投加二氧化碳气体使沉淀池出水pH控制在7.2±0.1,避免了混凝剂聚铝的过量投加,确保沉淀池出水的铝控制在0.20~0.30 mg/L,出厂水平均pH为7.41,出厂水的铝稳定低于0.08 mg/L。通过对该水厂各工艺段出水的pH和铝等指标进行检测,探究了臭氧/生物活性炭深度处理水厂对铝的去除机理,为高温季节自来水厂控铝提供了技术支撑。

Algae blooms of raw water in high temperature season lead to the increase in raw water pH,which poses a challenge to aluminum control in water treatment plant.Huinan Water Treatment Plant has built a new carbon dioxide pH regulation process with scale of 44×10^(4)m^(3)/d.The carbon dioxide aluminum control test was carried out in August 2022,and the water quality of the whole process was analyzed.When the temperature of raw water from Qingcaosha Reservoir exceeded 29℃in high temperature season,the pH of precipitated effluent was controlled at 7.2±0.1 by adding carbon dioxide gas,which avoided the excessive dosage of coagulant(polyaluminum),and ensured that the aluminum in precipitated effluent was controlled between 0.20 mg/L and 0.30 mg/L,the average pH of the product water was 7.41 and the aluminum in the product water stabilized below 0.08 mg/L.The removal mechanism of aluminum in ozone/biological activated carbon advanced treatment process was explored through the detection of pH and aluminum in each unit of the water treatment plant,so as to provide technical support for the control of aluminum in water treatment plants in high temperature season.