title: Influences of D-tyrosine on the stability of activated sludge flocs.
abstract: The sludge floc stability is essential for the solid/liquid separation in biological wastewater treatment. In this study, the effect of an exogenous d-tyrosine on the shear stability and surface characteristics of activated sludge flocs was investigated. Sludge flocs were found to be less stable in the addition of d-tyrosine. d-Tyrosine inhibited the production of extracellular polymeric substances (EPS) especially for the proteins. A high correlation coefficient was observed between the composition of EPS fraction and d-tyrosine content. In addition, the hydrophobicity of sludge flocs was reduced and the zeta potential was more negative with the content of d-tyrosine increased. A linear relationship between the extracellular polymeric substances and surface characteristics for sludge flocs indicated that the inhibited EPS production may be responsible for the instability of sludge upon the addition of d-tyrosine.
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, China.
authors.forename: Yi-Fu
authors.initials: YF
authors.lastname: Wang
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, China. Electronic address: xuefeisun@sdu.edu.cn.
authors.forename: Xue-Fei
authors.initials: XF
authors.lastname: Sun
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, China.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Xia
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, China.
authors.forename: Su-Fang
authors.initials: SF
authors.lastname: Xing
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Song
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, China. Electronic address: wsg@sdu.edu.cn.
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Wang
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D001704:Biopolymers / Q000096:biosynthesis; D005427:Flocculation / Q000187:drug effects; D008970:Molecular Weight; D011134:Polysaccharides / Q000032:analysis; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D055672:Static Electricity; D013499:Surface Properties; D014443:Tyrosine / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D001704:Biopolymers; D011134:Polysaccharides; D012722:Sewage; D014443:Tyrosine
keywords: Microbial extracellular polymeric substances (EPS); Sludge flocs; Stability; Surface characteristics; d-Tyrosine