Investigating the coagulation of non-proteinaceous algal organic matter: Optimizing coagulation performance and identification of removal mechanisms

作     者：Jana Naceradska Katerina Novotna Lenka Cermakova Tomas Cajthaml Martin Pivokonsky 

作者机构：Institute of Hydrodynamics of the Czech Academy of Sciences Institute of Microbiology of the Czech Academy of Sciences 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2019年第31卷第5期

页      面：25-34页

核心收录：

学科分类：08[工学] 0815[工学-水利工程] 

基　　金：supported by the Czech Science Foundation (No. GA18-14445S) by the institutional support of the Czech Academy of Sciences (RVO: 67985874) 

主　　题：Algal organic matter Chlorella vulgaris Coagulation Flocculation Non-proteinaceous matter Water treatment 

摘      要：The removal of algal organic matter(AOM) is a growing concern for the water treatment industry worldwide. The current study investigates coagulation of non-proteinaceous AOM(AOM after protein separation), which has been minimally explored compared with proteinaceous fractions. Jar tests with either aluminum sulphate(alum) or polyaluminium chloride(PACl) were performed at doses of 0.2–3.0 mg Al per 1 mg of dissolved organic carbon in the p H range 3.0–10.5. Additionally, non-proteinaceous matter was characterized in terms of charge, molecular weight and carbohydrate content to assess the treatability of its different fractions. Results showed that only up to 25% of non-proteinaceous AOM can be removed by coagulation under optimized conditions. The optimal coagulation p H(6.6–8.0 for alum and 7.5–9.0 for PACl) and low surface charge of the removed fraction indicated that the prevailing coagulation mechanism was adsorption of non-proteinaceous matter onto aluminum hydroxide precipitates. The lowest residual Al concentrations were achieved in very narrow p H ranges, especially in the case of PACl. High-molecular weight saccharidelike organics were amenable to coagulation compared to low-molecular weight( 3 k Da)substances. Their high content in non-proteinaceous matter(about 67%) was the reason for its low removal. Comparison with our previous studies implies that proteinaceous and nonproteinaceous matter is coagulated under different conditions due to the employment of diverse coagulation mechanisms. The study suggests that further research should focus on the removal of low-molecular weight AOM, reluctant to coagulate, with other treatment processes to minimize its detrimental effect on water safety.