Abiological Granular Sludge Formation Benefit for Heavy Metal Wastewater Treatment Using Sulfide Precipitation. Issue 4 (22nd March 2017)

• Record Type: Journal Article
• Authors: Yan, Xu; Chai, Liyuan; Li, Qingzhu; Ye, Lijun; Yang, Bentao; Wang, Qingwei
• Is Part Of: Clean. Volume 45:Issue 4(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-03-22
• Subjects: Metal sulfide precipitation -- Settling performance -- Solid–liquid separation -- Heavy metal wastewater; Water quality -- Periodicals; Water -- Pollution -- Periodicals; Pollution -- Periodicals; Bioremediation -- Periodicals; Sewage -- Periodicals; Water chemistry -- Periodicals; 333.7205
• DOI: 10.1002/clen.201500730
• Languages: English
• ISSNs: 1863-0650

Abstract

Abstract : Solid–liquid separation is a fundamental and ubiquitous process in water purification. Previously, an abiological granular sludge (ABGS) formation strategy was developed to improve the solid–liquid separation in heavy metal wastewater treatment. Although this strategy can be effectively applied in hydroxide precipitation, it remains challenging to apply it to other precipitation processes and real wastewater. Here, conditions for ABGS formation in the sulfide precipitation were first optimized. The effect of pH, seed dosage, and flocculant dosage on settling velocity and metal removal was systematically investigated. The results showed that the settling velocity of ABGS reached up to 3.7 cm/s and the volume of ABGS was compressed to one fifth of the original under optimal conditions, that is, pH of 8.5, seeds dosage of 0.25 g/L, and polyacrylamide dosage of 10 mg/L. Moreover, the ABGS formed in the process was analyzed for morphology and phase composition to provide insight into the formation mechanism, involving surface nucleation and aggregation, flocculation, and rearrangement. Under the optimized conditions, real Pb–Zn smelting wastewater was treated. The settling velocity (3.4 cm/s) of ABGS formed in real wastewater was as high as that in synthetic wastewater. Therefore, the ABGS strategy is potential to be scaled up to industrial application. Abstract : Metal sulfide precipitation features low sludge settling performance in heavy metal wastewater treatment. To solve this problem, an ABGS formation strategy is developed. The sludge settling performance can be significantly increased from 0.4 to 3.7 cm/s under optimal conditions. Besides, a surface nucleation and aggregation mechanism for ABGS formation is first proposed in this study.