title: The removal characteristics of natural organic matter in the recycling of drinking water treatment sludge: Role of solubilized organics.
abstract: To clarify the role of solubilized organics derived from drinking water treatment sludge (DWTS) in the elimination of natural organic matter (NOM) in the DWTS recycling process, a probe sonoreactor at a frequency of 25 kHz was used to solubilize the organics at varied specific energies. The coagulation behavior related to NOM removal in recycling the sonicated DWTS with and without solubilized organics was evaluated, and the effect on organic fractionations in coagulated water was determined. The study results could provide useful implications in designing DWTS recycling processes that avoid the enrichment of organic matter. Our results indicate that DWTS was disrupted through a low release of soluble chemical oxygen demand (SCOD) and proteins, which could deteriorate the coagulated water quality under the specific energy of 37.87-1212.1 kW h/kg TS. The optimal coagulation behavior for NOM removal was achieved by recycling the sonicated DWTS without solubilized organics at 151.5 kW h/kg TS specific energy. Recycling the sonicated DWTS could increase the enrichment potential of weakly hydrophobic acid, hydrophilic matter, and <3 kDa fractions; the enrichment risks could be reduced by discharging the solubilized organics. Fluorescent characteristic analysis indicated that when recycling the sonicated DWTS without solubilized organics, the removal of humic-like substances was limited, whereas removal of protein-like substances was enhanced, lowering the enrichment potential of protein-like substances.
authors.affiliation: The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China. Electronic address: yangyanling@bjut.edu.cn.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Yang
authors.affiliation: The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Xing
authors.initials: X
authors.lastname: Li
authors.affiliation: The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Siyang
authors.initials: S
authors.lastname: Ji
authors.affiliation: The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.affiliation: The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Qingping
authors.initials: Q
authors.lastname: Zeng
authors.affiliation: The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Xinghang
authors.initials: X
authors.lastname: Han
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D060766:Drinking Water / Q000737:chemistry*; D005110:Extracellular Space / Q000737:chemistry; D042541:Intracellular Space / Q000737:chemistry; D009930:Organic Chemicals / Q000737:chemistry* / Q000302:isolation & purification*; D059027:Recycling; D012722:Sewage / Q000737:chemistry*; D012995:Solubility; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*
chemical_list: D060766:Drinking Water; D009930:Organic Chemicals; D012722:Sewage; D014874:Water Pollutants, Chemical
keywords: Coagulation; Drinking water treatment sludge; Enrichment potential; Natural organic matter; Organic solubilization; Recycling; Ultrasound