title: Formation of abiological granular sludge - a facile and bioinspired proposal for improving sludge settling performance during heavy metal wastewater treatment.
abstract: Heavy metal contamination in wastewater poses a severe threat to the environment and public health. Chemical precipitation is the most conventional process for heavy metal wastewater treatment. However, the flocculent structure of chemical precipitation sludge raises the problem of poor sludge settling performance that is difficult to overcome. Inspired by the biological granular sludge (BGS) formation process, we report here a facile and effective strategy to produce abiological granular sludge (ABGS) to solve this problem. In this procedure, controlled double-jet precipitation was performed to simulate the cell multiplication process in BGS formation by controlling the solution supersaturation. Meanwhile, ZnO seeds and flocculant polyacrylamide were added to simulate the role of nuclei growth and extracellular polymeric substances in BGS formation process, respectively. This procedure generates ABGS with a dense structure, large size and regular spherical morphology. The settling velocity of ABGS can reach up to 3.0cms(-1), significantly higher than that of flocculent sludge (<1cms(-1)).
authors: School of Metallurgy and Environment, Central South University, Changsha 410083, China.
authors: Xu
authors: X
authors: Yan
authors: School of Metallurgy and Environment, Central South University, Changsha 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha 410083, China.
authors: Qingzhu
authors: Q
authors: Li
authors: School of Metallurgy and Environment, Central South University, Changsha 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha 410083, China. Electronic address: lychai@csu.edu.cn.
authors: Liyuan
authors: L
authors: Chai
authors: School of Metallurgy and Environment, Central South University, Changsha 410083, China.
authors: Bentao
authors: B
authors: Yang
authors: School of Metallurgy and Environment, Central South University, Changsha 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha 410083, China.
authors: Qingwei
authors: Q
authors: Wang
mesh_terms: D011232:Chemical Precipitation; D005427:Flocculation; D019216:Metals, Heavy / Q000737:chemistry*; D008956:Models, Chemical; D012722:Sewage / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015034:Zinc Oxide
chemical_list: D019216:Metals, Heavy; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical; D015034:Zinc Oxide
keywords: Abiological granular sludge; Controlled double-jet precipitation; Heavy metal wastewater; Settling performance