Carrousel氧化沟处理工业和生活混合污水的应用

昌邑城西污水处理厂根据工业和生活混合污水的水质特点及进水量,选用Carrousel氧化沟处理工艺,并在氧化沟前增设厌氧池和缺氧池,提高脱氮除磷的效果。工程调试及运行的实践表明,该工艺运行稳定且处理效果好,出水水质达到GB18918-2002《城镇污水处理厂污染物排放标准》的二级标准。     

微孔曝气Carrousel氧化沟脱氮除磷效果研究

七里店污水净化厂采用微孔曝气Carrousel氧化沟工艺。在日处理量约为改造工程设计规模的2倍条件下,氧化沟水力停留时间仅为5 h,系统出水各项指标均达到GB 18918—2002《城镇污水处理厂污染物排放标准》的二级标准。氧化沟内存在同步硝化反硝化过程,但硝化不彻底,脱氮效率不高,氧化沟内没有严格的厌氧分区,但生物除磷效率高。系统存在二沉池尾水氮磷含量增高问题。通过改变运行条件,增加氧化沟水力停留时间,调整曝气分区,辅助投药除磷等手段可以进一步提高出水水质,实现高标准排放。     

AOR工艺的设计研究

AOR是传统活性污泥法与氧化沟结合的一种新型生化反应器。具有较高的脱氮除磷功能,同时独特的污泥恢复区的设计,使得回流污泥集中适当充氧,另外采用同心圆结构,使每个区形成循环流态,因此是一种高效、节能、适应性强的污水处理工艺。在对AOR反应器分析研究的基础上,提出满足生物脱氮除磷的动力学设计研究方法,并对其设计计算公式进行推导。     

氧化沟脱氮除磷改造工程实例分析

结合城镇污水处理厂脱氮除磷技术改造工程实例,对老氧化沟进行功能区划分,确定明显的缺氧区和好氧区,采取措施增加好氧区溶解氧浓度,降低缺氧区溶解氧浓度.运行结果表明,系统出水主要指标稳定达到GB 18918-2002<城镇污水处理厂污染物排放标准>一级A标准.     

生物脱氮除磷技术及其发展趋势

文章系统地概述了废水生物脱氮除磷的机理，分析了城市污水生物脱氮除磷的成熟工艺技术，阐明A2／O系列、SBR系列和氧化沟系列的工艺流程和脱氮除磷的作用，探讨了城市污水生物脱氮除磷技术在碳源需求、短程生物脱氮和反硝化聚磷菌等方面的发展趋势。     

辽河流域15万m~3/d城市污水处理工艺设计

对于含有大量的BOD_5,COD,SS,NH_4-N、磷等污染物的某城市污水,采用设置厌氧、缺氧段的Carrousel氧化沟(即A~2/C氧化沟)工艺进行处理。运行结果表明,该工艺实现了无动力回流,流程简单,脱氮除磷效率高,处理出水达到了《城镇污水处理厂污染物排放标准》(GB 18918-2002)中的一级B标准。     

养猪废水氮磷污染及其深度脱氮除磷技术探讨

通过对规模化养猪场废水氮磷污染监测，揭示氮磷污染现状；研究生物脱氮除磷的机理和途径，指出传统A/O工工氮除磷局限性；探讨养猪业废水在沼气厌氧发酵基础上进行深度脱氮除磷的水生生物氧化塘工艺的可行性。     

新型AOA工艺脱氮除磷效果研究

从系统内碳源有效利用出发,将兼氧区混合液分流至缺氧区,利用PAO(聚磷菌)储存的内碳源PHA(聚羟基链烷酸)作为缺氧区碳源,开发出新型后置反硝化除磷AOA工艺。本文系统研究了污泥回流比(R)、混合液分流比(F)等对脱氮除磷效果的影响,探讨了新型AOA工艺脱氮除磷的过程特征,测定了污泥的吸磷速率,分析了系统内碳源转化、利用和氮磷平衡,结果表明,新型AOA工艺具有较好的除磷脱氮功能。     

多级厌氧缺氧好氧活性污泥法新工艺研究

多级厌氧缺氧好氧活性污泥法是由若干个厌氧缺氧好氧串联的形式组成,利用分段厌氧进水,形成多级厌氧-缺氧和多级缺氧-好氧同时交替运行,具有反硝化除磷和高效脱氮功能,采用无内回流技术,通过调节流量比值实现强化除磷与强化脱氮的控制目标,并具有污泥浓度高、抗冲击能力强、污泥减量、优化利用碳源、节省运行能耗和曝气量等特点,是节能型高效除磷脱氮新工艺,为城市污水高效除磷脱氮提供新的思路及途径。     

Carrousel~氧化沟技术发展研究

本文阐述了Carrousel氧化沟系统的主要优点、工艺演变形式和原理,认为现代脱氮除磷理论的发展是Carrousel氧化沟技术的发展推动力,同时讨论了Carrousel氧化沟技术的未来研究方向。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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