Invertebrate community characteristics in biologically active carbon filter

Biologically active carbon (BAC) system was set up in a water plant of South China during January to December 2007,to study the invertebrate community characteristics of BAC filter.Thirty-seven invertebrate species were found,of which 28 belonging to rotifers.Filter operation could lead to an output of invertebrates in high abundances with the filtrate,and the maximum density could reach 5608 individuals/m 3.Average abundances in the effluent water increased in 27-33 folds in comparison to the influent water during the sampling period.Invertebrate community succession had the following trend:filter-feeding animals → small benthic invertebrates → large benthic and resistant invertebrates.Abundances of large-sized invertebrates (copepod adult and oligochaete) at bigger-media column were significantly higher than that at small-media column.The results implied the abundant species diversity of invertebrate in BAC filter.The relationship between invertebrate and biofilm still remain to be studied in detail.     

Contributions of biofilm and suspended sludge to nitrogen transformation and nitrous oxide emission in hybrid sequencing batch system

Hybrid system combines the nature of suspended growth and attached growth has been widely applied to wastewater treatment. In this research, the contributions to N transformation and N2O emission by biofilm and suspended sludge in the hybrid sequencingbatch reactor for a simultaneous nitrification, denitrification and phosphorus removal process were investigated. For the hybrid system, nitrification occurred mostly in the suspended sludge, while the biofilm played the major role in denitrification. The interaction of the biofilm and the suspended sludge in the same reactor resulted in a better overall nitrogen removal performance with simultaneous nitrification and denitrification. However, N2O emission was the main end product of nitrogen removal for the hybrid system; while it was N2 for the biofilm. The relative low N2O emissions from the pure biofilm and the pure suspended sludge corresponded to the relatively high nitrate at the end of the aeration period compared with the hybrid system.     

DPB污泥浓度对反硝化除磷的影响

为了进一步了解反硝化聚磷菌（DPB）污泥质量浓度（MLSS）对反硝化除磷过程的影响,进行一系列厌氧、缺氧模拟试验．研究考察DPB污泥的MLSS对厌氧释磷、缺氧反硝化吸磷的影响。结果表明：MLSS越高,释、吸磷速率及反硝化速率越高;MLSS对释、吸磷比速率和反硝化比速率的影响较小;厌氧总释磷量由污水中可利用COD的多少决定,DPB污泥的MLSS只影响到达释磷平衡的时间：污水中含氮量偏低引起反硝化吸磷段NO3^-不足时,DPB污泥厌氧释磷量高于反硝化吸磷量．MLSS越高经缺氧反硝化吸磷处理后水中含磷量越高。     

悬浮填料与好氧颗粒污泥脱氮对比试验研究

常温连续流条件下,分别在两个反应器中投加悬浮填料和接种好氧颗粒污泥,通过控制工艺条件,两个反应器中均实现了同步硝化反硝化(SND)。改变进水溶解氧DO浓度、碳氮比(C/N)、有机负荷和NH4+-N负荷,分析比较了两个反应器脱氮的重要工艺条件。试验结果表明,在相同的工艺条件下,悬浮填料脱氮最佳DO浓度为1.0mg/L左右,最佳C/N为12;好氧颗粒污泥脱氮最佳DO浓度为1.5mg/L,最佳C/N为5。提高进水有机负荷,两个反应器COD去除率均稳定在较高的水平。NH4+-N浓度升高时,反应器脱氮效率均降低,好氧颗粒污泥比悬浮填料更耐冲击负荷。     

DASB反应器处理生活污水的试验研究

DASB反应器作为新型现代厌氧反应器,具有结构简单、运行方便,处理效果好等优点,在处理生活污水方面有着广泛的应用前景。研究了常温条件下,DASB处理生活污水的启动运行,得出在最佳水力停留时间6h时,COD和SS的平均去除率分别达到81．48％和86．07％。     

水生高等植物对水中悬浮固体去除效果的研究

文章研究了含不同浓度悬浮物的水流,在流经由长江中下游典型水生植物风车草、石菖蒲、菱、金鱼藻、轮叶黑藻、亚洲苦草所构建的水生高等植物群落时悬浮固体浓度的变化规律,分析了群落及群落中每种水生高等植物对悬浮固体的去除效果。结果表明,所构建的水生高等植物群落能够有效地降低水体中悬浮固体的浓度,但不同种类的水生高等植物对悬浮固体浓度降低的效果相差很大。     

Numerical simulation of a horizontal sedimentation tank considering sludge recirculation

Most research conducted on the concentration distribution of sediment in the sedimentation tank does not consider the role of the suction dredge. To analyze concentration distribution more accurately, a suspended sediment transportation model was constructed and the velocity field in the sedimentation tank was determined based on the influence of the suction dredge. An application model was then used to analyze the concentration distribution in the sedimentation tank when the suction dredge was fixed, with results showing that distribution was in accordance with theoretical analysis. The simulated value of the outlet concentration was similar to the experimental value, and the trends of the isoconcentration distribution curves, as well as the vertical distribution curves of the five monitoring sections acquired through simulations, were almost the same as curves acquired through experimentation. The di erences between the simulated values and the experimental values were significant.     

毛细压力法对水处理滤料亲油亲水比的研究

基于Washburn方程,定义了滤料的亲油亲水比(LHR),利用毛细压力法测定了果壳、锰砂、陶粒、石英砂和瓷砂的润湿速率,计算了LHR值,并对滤料的表面微观结构进行了研究.实验表明,直线拟合程度较好,结果重现性较高.实验方法可行.数据可靠.其中果壳的LHR值最大,达到66.87,表现出了最强的亲油性,其次是锰砂、陶粒、石英砂,三者的亲油性略好于瓷砂,其LHR值分别为1.24、1.22、1.16和0.80,与XPS和FTIR分析结果一致,证实了滤料LHR值的差异主要取决于滤料表面微观结构的不同.     

西江上游河水悬浮物中稀土元素的地球化学特征

采用改进的BCR逐级提取法和ICP-MS测试技术,对西江上游河流悬浮物中稀土元素进行了研究。结果表明:河流悬浮物稀土元素总量的含量变化范围在188～402mg/kg之间,并主要来源于流域内岩石的风化,反映了源区的物质特征。西江上游河水悬浮物中三种非稳定态(即酸可提取态、铁锰氧化物结合态和有机物硫化物结合态)稀土元素页岩(PAAS)标准化配分模式均显示出中稀土富集的特征。这种配分模式可能是由于流域内广布的海相沉积岩中磷酸盐矿物的风化所造成的。稳定态(即残渣态)的配分曲线较为平直,没有体现出明显的稀土分异。悬浮态稀土各赋存形态含量的顺序为:残渣态有机物硫化物结合态、铁锰氧化物结合态酸可提取态。中稀土元素Sm、Eu、Gd相对于轻、重稀土元素的稳定态所占比例偏低,而相对于三种非稳定态所占比例偏高,反映了其潜在的地球化学活性。     

小球藻来源溶解有机质的光化学降解特性

利用三维荧光光谱-平行因子分析(EEM-PARAFAC)手段结合吸收光谱分析,研究了小球藻指数期和稳定期培养液中溶解有机物(DOM)在秋季天然太阳辐射作用下的光降解动力学特征.结果表明,小球藻生长过程中除能产生短波激发类腐殖质组分C1(其荧光峰的激发/发射波长位置为240,335 nm /406 nm)及类蛋白质组分C3(225,275 nm/334 nm)外,还会形成长波激发类腐殖质组分C2(260,395 nm /502 nm),表明C2组分并非仅有传统认为的陆源属性,同时也具有自生源属性.稳定期培养液的吸收光谱在250~300 nm范围内出现的肩峰,可用于指示水环境中现场自生源的贡献.不同生长时期培养液中DOM的吸收系数和荧光组分的降解动力学都符合一级反应方程.稳定期类腐殖质荧光组分(C1和C2)的光降解程度略高于指数期,但指数期类色氨酸组分(C3)的光降解程度略高于稳定期.经太阳辐照6 d后,小球藻培养液的吸收系数a₃₅₀及各荧光组分的平均损失率分别达到83.0%、84.0%、64.8%和80.0%,对应的半衰期只有1.6~5.0 d,揭示出藻类自生来源的DOM具有很强的光化学降解活性.