A new indicator of ionic polymeric flocculants for the removal of heavy metals anions: Specific charge density. (9th May 2019)

• Record Type: Journal Article
• Authors: Hou, Rong; Zhao, He; Cao, Hongbin; Ning, Jingheng
• Is Part Of: Water environment research. Volume 91:Number 9(2019)
• Page Start: 888
• Page End: 897
• Publication Date: 2019-05-09
• Subjects: Aanionic pollutants -- Flocculation -- Ionic polymer flocculants -- PDADMAC -- Removal efficiency -- Specific charge density; Water quality management -- Periodicals; Water -- Purification -- Periodicals; Water -- Pollution -- Periodicals; Water -- Pollution; Water -- Purification; Water quality management; Sewage; Water Pollution; Periodicals; Electronic journals; Periodicals; 628.16
• DOI: 10.1002/wer.1126
• Languages: English
• ISSNs: 1061-4303

Abstract

Abstract : Abstract: Ionic polymeric flocculants, as useful and widely used technology, have been applied for heavy metal pollution control. However, although molecular weight is an important indicator, it is not a comprehensive indicator for evaluating flocculation efficiencies of ionic flocculants. Herein, specific charge density (SCD), defined as charge density of unit molecular weight, is a new indicator to evaluate the performance of ionic polymer flocculants. Polydiallyldimethylammonium chloride (PDADMAC) as coagulant aid is investigated to flocculate different anionic pollutants. The results indicate that PDADMAC with a high SCD value could benefit to the flocculation efficiency of anionic pollutants. According to statistical analysis, the average pollutants residual could decrease to 8.64%–32.27% by that with high SCD value, especially for high valence pollutants with a decrease from 58.97%–60.40% to 27.35%–32.27%. The indicator of SCD values not only could characterize the performance of polymer flocculants but also provide a new sight of the flocculation mechanism of polymeric flocculants. Practitioner points: Specific Charge Density (SCD) is defined as charge density of unit molecularweight. SCD as a new indicator to evaluate comprehensively the performance of flocculants. Removal efficiencies by flocculation increase with SCD value of PDADMAC increase. Effect of SCD of PDADMAC on removal of pollutant with high valence is significant. SCD of PDADMAC is less indicative for removal of pollutant with low valence. Abstract : Specific Charge Density (SCD) is a new indicator to evaluate the performance of ionic polymeric flocculants. Polymeric flocculants with a high SCD value could benefit to the flocculation efficiency of anionic pollutants. The valence of pollutants would have an impact on removal by different SCD values of PDADMAC.