改性活性炭催化臭氧深度处理化工废水的研究

采用非均相催化臭氧氧化工艺深度处理化工废水二级生化出水,探索负载不同活性组分的活性炭催化剂及该工艺处理化工废水的影响因素。结果表明:当进水COD为85~110 mg/L,臭氧投加量为60 mg/L,催化剂投加量为200 mg/L Cr时,臭氧氧化、ACCA-1、ACCA-2和ACCA-3催化臭氧氧化对出水COD的平均去除率分别为22.46%、32.7%、40.5%和35.7%,3种催化剂均可强化臭氧氧化效果。活性炭催化剂能提高臭氧利用率,叔丁醇对ACCA-2抑制效果最明显。     

制革含硫废水脱硫的预处理

通过催化氧化法和化学混凝法预处理制革含硫废水的脱硫探索试验,发现单一催化氧化法的曝气时间太长;单一化学混凝法,处理后出水不能符合后续生物处理含硫<40mg/L的容许浓度。为此,提出了催化剂投加量为100～200mg(Mn~(2+)/L(废水)、催化曝气1h、续加混凝剂聚合铁1.5mg/L的催化氧化—化学混凝法,处理含硫浓度100～200mg/L的废水,硫化物去除率达90％以上,出水含硫<40mg/L。     

臭氧催化氧化处理苯酚废水研究

采用臭氧催化氧化法处理苯酚废水,用自制的催化剂--活性炭负载金属氧化物(Fe/AC,Cu/AC,Mn/AC)对模拟苯酚废水进行臭氧催化氧化比较,并对影响催化氧化效果的几个因素:不同的活性组成分、初始COD、反应时间、pH值进行了分析。结果表明:在每次处理量为500mL苯酚废水时,负载铁氧化物的活性炭催化剂用量为15g、反应时间为40min、COD初始浓度为1000mg/L、pH值为9、臭氧投加量为10mg/L,催化氧化具有较佳的效果;催化剂的重复利用性较好,连续使用11次,COD的去除率仍可达70.4%;通过GC-MS的检测,推测其反应机理为:苯酚→苯二酚类及苯醌类化合物→醛酮类化合物→羧酸类化合物→CO2,H2O     

催化臭氧氧化预处理垃圾渗滤液

采用浸渍法制备载铜活性炭催化剂,系统地研究了催化氧化法对垃圾渗滤液中的COD和氨氮去除效果,对臭氧氧化和催化臭氧氧化效率进行了对比。在该方法下制备的催化剂中,活性组分金属铜的含量为2.89%。结果表明:在投加催化剂的情况下,COD的去除效率可得到显著提高。实验结果表明:处理COD为4980mg/L,氨氮为2100mg/L的垃圾渗滤液废水,在室温、pH为3、反应时间为120min、催化剂投加量为150g/L、臭氧的流量为5.2mg/min的条件下,废水中的COD及氨氮的去除率分别达到达81.9%和99.04%。     

高浓度食品添加剂废水中试研究

根据食品添加剂废水水质变化大,成分复杂特点,提出了"水解酸化—接触氧化—臭氧催化氧化—曝气生物滤池(BAF)"的组合工艺。废水COD从进水2000～7000mg/L降到100mg/L以下,最低为33mg/L,排放水质达到国家排放标准。水解酸化系统使废水平均COD从5290mg/L降到2323mg/L,并使大颗粒难降解分子部分转化为小颗粒可降解分子,为后续的接触氧化系统处理提供良好的条件,接触氧化出水平均COD为268mg/L。接触氧化出水含较多难生物降解有机物,经O3氧化预处理后在COD下降45%的情况下其BOD5/COD由0.3升为0.44,更易于生化降解。废水经曝气生物滤池平均出水COD为66mg/L。中试研究表明,水解酸化系统和臭氧催化氧化(负载MnO2的陶粒为催化剂)-曝气生物滤池深度处理系统是该工艺处理高浓度废水稳定达标的关键。     

微波辅助均相催化氧化处理吡虫啉农药废水

对微波辅助均相催化氧化处理吡虫啉农药废水进行了研究,通过考察H2O2投加量、均相催化剂Fe2＋浓度、微波辐照时间及功率、废水温度、废水pH值等因素对该农药废水COD处理效果的影响,获得了最佳工艺条件：即100ml初始COD浓度为268mg／L的农药废水,H202投加量为26．52g/L,均相催化剂Fe2＋浓度为109．8mg／L,在微波功率119W,辐射时间为4min,pH为6的条件下,COD去除率可达78．51％。     

组合工艺在制药废水处理中的应用研究

制药废水成分复杂、毒性大、含难生物降解物质,是较难处理的工业废水,本文针对制药废水的特点,选用铁屑过滤-催化电解-生化-复合催化氧化的组合工艺对此废水进行针对性处理.实验数据表明：采用铁屑过滤-催化电解-生化-复合催化氧化的组合工艺处理农药废水,可以使废水COD从17 954 mg/L降至86mg/L,去除率达到99％以上,出水COD降至100 mg/L以下,达到《污水综合排放标准》（GB 8978-1996）一级排放标准要求.     

含酚废水α-Fe2O3催化臭氧氧化参数优化及机理分析

传统工艺对含酚废水的处理效果有限,催化臭氧氧化技术能够有效处理含酚废水。α-Fe₂O₃在试验中表现出了高臭氧催化活性,催化产生的·OH可对苯酚及中间产物进行无选择性矿化,显著增强了污染物去除效果和臭氧利用水平。为明确催化臭氧氧化过程主要影响因素并优化工艺参数,以苯酚模拟含酚废水,设计了L₁₆(4⁴)正交试验。结果表明,臭氧投加量、催化剂投加量、pH、反应时间是COD去除率及单位臭氧COD降解量的主要影响因素,其中,臭氧投加量与反应时间的影响较为显著。方差分析与试验验证表明,催化剂投加量对COD去除率影响较小,pH对单位臭氧COD降解量影响较小。通过权矩阵计算得到优化后的反应条件：臭氧投加量为5 mg/(L·min),催化剂投加量为0.10 g/L,pH为9,反应时间为45 min。叔丁醇屏蔽试验表明,·OH显著促进了催化臭氧氧化进程。     

催化臭氧氧化处理煤化工高盐废水COD研究

针对某企业因高盐废水COD过高造成膜易污堵和蒸发结晶效果不好等问题,研制了4种臭氧催化剂,对高盐废水小试和侧线研究后得出结论:(1)4种催化剂对COD均有去除效果,催化剂C的去除率最高为51%;(2)采用催化剂C小试确定最佳反应条件为:臭氧投加量300 mg/L、空速1 h-1、p H值8,臭氧转移率为81%;(3)开展现场侧线研究,进水COD在124～144 mg/L时,出水COD小于85 mg/L,平均去除率大于40%。研究表明,催化臭氧氧化处理高盐废水技术上可靠、工业化可行,该技术成果可以在高盐废水处理改造提升和新建项目的废水处理方案中借鉴和应用。     

催化臭氧氧化去除模拟海产养殖废水中氟苯尼考

氟苯尼考(Florfenicol,FF)是海产养殖中应用的一种抗生素。但是,残留的FF用常规方法难以去除,导致海水污染。以负载Mn-Ce氧化物的γ-Al_2O_3为催化剂,采用催化臭氧氧化技术去除模拟海产养殖废水中的FF,考察了臭氧浓度、催化剂用量等工艺参数以及海水中高锰酸钾指数(COD_(Mn))和氨氮浓度对FF去除率的影响。运用液相色谱-质谱(LC-MS)联用技术对FF降解中间产物进行定性分析以确定FF的降解途径,并对处理前后的废水进行生物毒性研究。研究结果表明:Mn-CeOx/γ-Al_2O_3催化体系中臭氧浓度为12. 86 mg/L,催化剂投加量为200 g,初始ρ(FF)为25mg/L,反应20 min,FF去除率可接近100%;随着COD_(Mn)和氨氮浓度的增加,会使FF去除率降低;经Mn-CeOx/γ-Al_2O_3催化臭氧氧化,FF最终转化为CO_2和H_2O,废水的生物毒性得到有效下降。     

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.     

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.