Fenton-曝气生物滤池深度处理柠檬酸废水中试

柠檬酸废水(二级出水)具有可生化性差,难生物降解的特点,可采用Fenton氧化-曝气生物滤池组合工艺进行处理。试验表明:当H2O2投加量为最优化条件下的0.6m L/L时,Fenton氧化-曝气生物滤池组合工艺对COD有着良好并且稳定的去除效果。其中,Fenton起到改善废水可生化性作用,通过去除废水中的类腐殖酸、类富里酸组分,可以将废水ρ(BOD5)/ρ(COD)从0.26增加到0.75,后续曝气生物滤池继续对COD进行生物降解,组合工艺在15 d的连续运行条件下,COD去除率稳定在85%以上,出水ρ(COD)<50 mg/L。     

柠檬酸生产物废水处理工艺及展望

柠檬酸在我国行业应用中较为广泛,但由此产生的废水不容忽视.本文通过柠檬酸废水来源及水质状况分析,就光合细菌法、乳状液膜法、生产饲料酵母法和Fenton试剂氧化法四种工艺优点和不足以及实践运用进行详细论述,并对工艺发展方向进行了简要展望.     

柠檬酸中和废水回用技术研究

本文研究了柠檬酸中和废水回用工艺技术。中和废水经碱（ＮａＯＨ）沉淀和酸（Ｈ２ＳＯ４）中和预处理措施，直接用于发酵配料。实验用菌株Ｃ－９８自黑曲霉ＣＢＸ－１２分离获得。最佳发酵条件：总还原糖１４％￣１６％，麦麸２．５％，初始ｐＨ６．５，乙醇１．５％，同传统的柠檬酸废水处理工艺比较，该工艺在投资和运转成本方面具有潜在的优势。     

生物膜法处理柠檬酸废水的研究

针对柠檬酸废水可生化性差、成分复杂等特点,采用生物膜法进行处理.实验结果表明：该工况对COD、NH3-N具有较好的去除效率,去除率分别为93％、97％,达到《污水综合排放标准》（GB8978-1996）一级标准.     

印染废水回用的反渗透预处理技术

针对印染废水回用时水中有机物浓度、盐度和色度高等问题,以苏南某污水处理厂中试试验基地(70%以上为印染废水)二级生化出水为研究对象,对混凝沉淀-超滤(以下称组合工艺1)、BAC(生物活性炭滤池)-超滤(组合工艺2)和混凝沉淀-BAC-超滤(组合工艺3)3种工艺进行比较研究,系统考察其作为反渗透预处理技术的可行性. 结果表明:组合工艺3对印染废水二级生化出水中COD_Cr、TCU(真色)及浊度的平均去除率分别为53.0%、49.2%和99.5%,UV₂₅₄下降了50.0%,均高于其他2个组合工艺. 对超滤膜表面污染阻力分布的测定可知,组合工艺3中不可逆污染造成膜污染的程度最轻. 此外,3种组合工艺的出水通过反渗透装置后的平均脱盐率分别为98.0%、97.5%和98.2%. 可见,针对该研究中涉及的二级生化出水,组合工艺3预处理工艺是反渗透预处理的最佳工艺.      

柠檬酸生产废水的治理

我国是世界上最大的柠檬酸生产和出口国，柠檬酸也是我国最大的生物出口产品，柠檬酸生产过程产生的大量高浓度有机废水引起的环境问题，长期以来一直是制约行业发展的主要因素之一。本文总结了柠檬酸生产废水治理的经验和问题，希望能给柠檬酸等高浓度有机废水的治理和环保管理提供一些帮助。     

生化燃料综合废水处理改扩建工程

某生化燃料综合废水处理改扩建工程采用"上旋流厌氧IC反应器和一体式氧化沟"主体工艺处理柠檬酸废水和综合废水,原水COD浓度在10 000~30 000 mg/L,经上旋流厌氧IC反应器处理后出水COD在2 000~2 500 mg/L,经一体式氧化沟处理后出水COD在200~250 mg/L,稳定达到排放标准:ρ(COD)≤300 mg/L。     

强化混凝与Fenton试剂氧化处理含聚采油废水的中试研究

采用强化混凝加Fenton试剂氧化技术组合工艺研究其对含聚采油废水的处理效果。分别考察了混凝反应pH及混凝药剂投加浓度和Fenton试剂氧化反应中H2O2以及Fe2+的投加浓度对含聚采油废水处理效果的影响。试验结果表明,在最佳反应条件下,废水的COD达到48 mg/L,SS达到9 mg/L,色度达到16倍,能够达到GB 8978—1996《污水综合排放标准》一级排放标准。强化混凝加Fenton试剂氧化技术组合工艺对含聚采油废水具有良好的处理效果。     

曝气生物滤池组合工艺处理肉类加工废水生产性试验研究

以实际工程调试为依据,阐述了曝气生物滤池组合工艺的原理和特点,通过运行结果分析及运行费用核算得出结论:该套组合工艺对地处北方的肉类加工企业,是一个技术可行、比较经济的废水处理方案     

利用光合细菌处理柠檬酸废水

利用光合细菌处理柠檬酸废水南通发酵厂管希夷，王济生南通市发酵厂与上海交通大学生物技术研究所在日本小栋正泰先生的帮助下，进行了利用光会细菌处理柠檬酸废水的大量试验，并建立了日处理！５０～ｓ００ｔ柠檬酸废水的装置，但由于仍有明显不足之处，该厂大胆采用了新...     

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.     

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.     

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.     

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.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

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

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Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.