石灰石对磷的吸附影响因素及其在污水深度处理中的应用.docVIP

 Influencing Factors of Limestone Sorption and Its Usage in Advanced Wastewater Treatment for Phosphorus Removal# 5 10 15 20 25 30 35 40 Li Linyong1, Zhang Hua2, Wang Dunqiu2* (1. School of RoadBridge, Zhejiang Institute of Communication, Hangzhou 311112; 2. College of Environmental Science and Engineering , Guilin University of Technology, Guilin 541004) Abstract: The aim of this article was to investigate the influencing factors of limestone(LS) adsorption for phosphorus(P) removal and the effect of treating the effluent from a municipal wastewater treatment plant(MWTP). Firstly a series of batch experiments were conducted to study the influencing factors of LS for P removal. Consequently, the P removal efficency increased with the temperature and was higher during the initial 3 h; the efficency was as high as 75% even at initial P content 50 mg/L or corresponding P/LS 3 mg/g; smaller LS particle size enhanced the adsorption of limestone; the efficiency was over 90% when pH was below 6.37 and decreased sharply with pH when it was above 8.15; sodium chloride as background electrolyte decreased the adsorption; organic acids including tartaric acid, oxalic acid, and citric acid suppressed the adsorption, and citric acid showed the strongest effect which proved to be effective material for the regeneration of saturated limestone. Then column study was conducted to evaluate the effect of the continuous vertical-flow limestone bed treating effluent from a MWTP with varying hydraulic retention time(HRTs). Over 80 days the effluent pH was between 7 and 9 which was suitable for growing plant; running period while effulent TP≤0.5 mg/L increased with HRTand shorter HRTs such as 1 or 1.5h was recommended. It showed that LS as a effective absorbent, was suitable for the substrate in constructed wetland for advanced treating effluent from MWTPs. Key words: Limestone; Environmental Engineering; Phosphorus; Substrate 0 Introduction Phosphorus(P) is one of the main triggerin