水华微囊藻混凝沉降去除过程中铝盐回收及循环使用  

STUDY ON THE ALUMINIUM SALTS RECOVERY AND RECYCLING DURING MICROCYSTIS FLOS-AQUAE REMOVAL USING COAGULATION SEDIMENTATION

作　　者：于桐泊 李莉莉 程绍哲 张海阳 张学治 YU Tong-Bo;LI Li-Li;CHENG Shao-Zhe;ZHANG Hai-Yang;ZHANG Xue-Zhi(College of Fisheries and Life Science,Dalian Ocean University,Dalian 116023,China;Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China)

机构地区：[1]大连海洋大学水产与生命学院,大连116023 [2]中国科学院水生生物研究所,武汉430072

出　　处：《水生生物学报》2022年第3期419-426,共8页Acta Hydrobiologica Sinica

基　　金：国家重点研发计划中美国际合作项目(2018YFE0110600)资助。

摘　　要：以水华微囊藻(Microcystis flos-aquae)为研究对象,对用聚合氯化铝和阳离子聚丙烯酰胺收获后的生物质进行酸洗处理回收铝盐并进行多次循环使用,以降低混凝沉降工艺中吨水处理成本。研究结果表明,总铝盐回收效率随酸洗次数增加而增大随后达到最大,而在较高的盐酸浓度或较高的液-固比条件下可最快达到较高的铝盐回收效率。回收铝盐可循环使用5次,且在相同Al^(3+)浓度下其用于水华微囊藻去除的效率始终高于新配制的聚合氯化铝。进一步对回收铝盐具有较高的去除效率进行分析,发现被同时洗脱的胞外聚合物(Extracellular polymeric substances,EPS)起到了助凝作用。通过经济技术分析发现,与不回收循环使用铝盐的0.60元/m^(3)含藻水的药剂成本相比,铝盐回收循环使用吨水药剂成本大幅降低,达到了0.30元/m^(3)含藻水。Coagulation-sedimentation process has been increasingly used in the treatment of algae-laden water,however,the cost share of coagulant is still the largest,which makes the cost of algae-laden-water treatment remain high.In this study,the harvested Microcystis flos-aquae biomass which contain polyaluminum chloride(PAC)and cationic polyacrylamide(CPAM)were washed to recover aluminum salts for the purpose of coagulant recycling.The purposes of this study were to reveal whether the presence of CPAM in the coagulation harvested biomass affect aluminum recover,to explore how does HCl concentration and liquid-solid ratio of HCl-biomass affect the aluminum recover efficiency,and to disclose the relationship between the HCl dosage and the amount of Al^(3+)recovered.The results showed that the recoveries of total aluminum salt increased with washing time,and then reached plateau after a certain number of washings.The highest recovery achieved at a higher concentration of HCl or a higher liquid-solid ratio.The recovered aluminum salt could be reused for 5 times,and its removal efficiency was always higher than that of the newly prepared PAC at the same concentration.Further analysis revealed that the extracellular polymeric substances(EPS)were eluted at the same time which enhanced the coagulation.Technical and economic analysis found that PAC recovery and recycling could significantly reduce the chemical cost during algae laden water treatment,from 0.60 to 0.30 RMB/m^(3).The results of study would be helpful to guide the practice of coagulation based microalgal harvesting for the purpose of coagulant recycling and biomass purification.

关 键 词：混凝沉降 聚合氯化铝 混凝剂回用 水华微囊藻 

分 类 号：X524[环境科学与工程—环境工程]