强化混凝技术处理东太湖原水研究

在常规混凝工艺确定的最佳处理条件下,考察了单独高锰酸钾(KMnO4)和次氯酸钠(NaClO)预氧化、单独投加粉末活性炭(PAC)以及KMnO4和PAC联用对混凝处理东太湖原水的强化效果。结果表明,聚氯化铝和硫酸铝的最佳投加量分别为20mg/L和30mg/L,聚氯化铝的混凝效果明显优于硫酸铝;投加KMnO4对浊度、CODMn和UV254的去除均有一定程度提高,但不利于原水氨氮的去除;投加PAC有显著的强化混凝作用,各指标去除率均有所提高;KMnO4和PAC联用能进一步提高水中UV254的去除率;预氧化大大提高了混凝对氨氮的去除效果,投加1mg/L NaClO对氨氮去除率可达100%。     

砂滤前置或后置对消毒副产物生成潜能的影响

采用常规一深度处理工艺处理东太湖原水,对比砂滤前置与后置对各工艺流程出水消毒副产物生成潜能去除效果的影响。研究发现,无论砂滤前置还是后置,生物活性炭工艺对有机物都有着良好的去除效果,整套工艺出水COD和uV。的去除率分别稳定在74．2％～87．1％和75．0％～80．2％。两套工艺对二甲基亚硝胺生成潜能（NDMAFP）的去除效果没有明显差别,出水NDMAFP降低35％～41％。砂滤前置工艺对三卤甲烷生成潜能（THMFP）和卤乙酸生成潜能（HAAFP）的控制效果优于砂滤后置工艺,砂滤前置工艺活性炭单元出水和砂滤后置工艺砂滤单元出水的THMFP分别降低31．0％～37．4％和28．2％～35．3％,HAAFP分别降低20．0％～24．6％和16．3％～23．2％。     

响应面分析法优化太湖原水作为水厂水源的预处理工艺

针对太湖水质,采用响应面法(RSM)优化臭氧-混凝工艺.在单因素试验的基础上,选取臭氧(O3)投加量、混凝剂投加量和停留时间为影响因子,CODMn去除率、浊度去除率和运行成本为目标响应,利用Box-Benhnkendesign(BBD)进行3因素3水平实验设计,研究各自变量间的单独与交互作用及对响应值的影响.根据拟合的线性二次回归方程得到臭氧-混凝的最佳工艺条件为:以硫酸铝作混凝剂时,O3投加量0.9 mg/L,混凝剂投加量35mg/L,接触时间17 min;以聚合氯化铝作混凝剂时,O3投加量0.9 mg/L,混凝剂投加量24 mg/L,接触时间17 min.该条件下可使臭氧-混凝过程中CODMn和浊度的去除率达到最大,同时运行成本费用最低.     

由混凝或气浮构成的组合工艺处理太湖原水比较

针对低温东太湖原水,考察常规+臭氧-生物活性炭(O₃-BAC)处理中气浮和沉淀两种工艺对出水水质的影响．结果表明:气浮工艺对原水浊度的去除效果明显优于沉淀工艺,平均去除率高约10.1％,无论是气浮还是沉淀工艺,经O₃-BAC深度处理后出水浊度均稳定在1 NTU以下;气浮工艺对有机物的去除效果略优于沉淀工艺,CODMn和DOC平均去除率分别高约5.4％和1.6％,常规处理工艺后出水有机物含量不能达标,O₃-BAC工艺出水CODMn稳定在0.5～2.1 mg／L,DOC稳定在0.3～2.0 mg／L;沉淀／气浮工艺只对腐殖质略有去除效果,砂滤对荧光物质几乎无去除作用,而O₃-BAC工艺是去除水中荧光类物质的主要手段;气浮工艺对藻类的去除效果略优于沉淀工艺,深度处理后出水硅藻活性和叶绿素浓度降为0,蓝藻仍保有部分活性．     

Quantitative analysis of trace levels ofβ-ionone in water by liquid-liquid- phase extraction-gas chromatography-mass spectrometry (LLE-GC-MS)

A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.