气浮-水解酸化-SBR工艺在屠宰废水处理中的应用研究

屠宰废水具有有机物含量高、可生化性较好等特点,因此生化处理是屠宰废水的主要工艺。某公司对屠宰废水采用"气浮-水解酸化-SBR"工艺进行处理,废水处理结果表明,当废水进水SS、COD cr、BOD5、NH3-N平均浓度分别为580 mg/L、1 900 mg/L、1 140 mg/L、54 mg/L时,出水SS、COD cr、BOD5、NH3-N平均浓度分别为45 mg/L、55 mg/L、15 mg/L、10 mg/L,出水水质指标满足《肉类加工工业水污染物排放标准》(GB 13457-92)的一级排放标准要求,废水中SS、COD cr、BOD5、NH3-N平均去除率分别为92%、97%、98.5%、72%。     

水解酸化/生物膜法SBR处理印染废水实验研究

针对印染废水污染物浓度高、种类多、色度高、可生化降解性差等特点,对印染废水采用水解酸化/生物膜法SBR进行处理,结果表明,该处理工艺处理效果较好,出水COD、色度、BOD5、NH3-N浓度分别为60~100 mg/L、50~70倍、20~24 mg/L、5~10 mg/L,平均去除率分别达到92.1%、86.5%、95%、90%。     

二级水解酸化-好氧工艺处理炼油废水的中试实验

用二级水解酸化-好氧工艺对某炼油厂废水进行了工业中试实验.在不设二沉池、污水不回流、H1池进水COD＜550mg/L时,本工艺O2池出水可使COD、Oil、Ar-OH、NH3-N、S2-的降解率分别达到94.1%,98.7%,99.3%,86.5%,100%,出水达标率100%.     

O_3-MBR法深度处理煤气废水

以经多级生物处理后的煤气废水为原水,采用O3-MBR组合工艺对其进行深度处理,以满足回用要求.结果表明:采用臭氧氧化工艺,当废水pH为11和臭氧投加量〔ρ(臭氧)〕为189.2mg/L时,CODCr和色度的去除率分别为46.5%和80.2%,ρ(BOD5)/ρ(CODCr)由0.02升至0.29,废水的可生化性得到明显改善;臭氧氧化工艺出水再通过MBR作进一步处理,CODCr,NH3-N和色度的去除率分别达23.0%,76.3%和70.0%,且出水水质稳定;总体上,废水经O3-MBR组合工艺处理,CODCr,NH3-N,色度和浊度的平均总去除率分别达到58.7%,76.3%,88.6%和95.1%;处理后出水的ρ(CODCr)50mg/L,ρ(NH3-N)5mg/L,浊度0.2NTU,色度约为30度,出水水质满足生产工艺回用的要求.     

水解酸化-SBR工艺处理印染废水的研究

用水解酸化-SBR工艺处理印染废水的实验结果表明,出水COD平均为102mg/L,COD去除率平均为89.9%,色度去除率平均为70%.在实际工程中应用水解酸化(A)-好氧(O)-SBR工艺处理印染废水,出水COD平均为67mg/L,COD去除率平均为81.5%,色度去除率平均为66.7%.表明以水解酸化为预处理手段可有效提高印染废水的可生化性,提高整个工艺的COD去除率.     

水解酸化-MBR组合工艺处理雏鸡孵化场废水

文章介绍了采用水解酸化-MBR组合工艺处理雏鸡孵化场废水的应用实例。结果表明,当进水COD、BOD5、NH3-N和SS浓度分别为1 230、268、22和456 mg/L时,污染物去除率依次分别为96.7%、97.5%、82.7%和98.6%。经该工艺处理后的出水水质稳定,并达到了《城镇污水处理厂污染物排放标准(GB 18918—2002)》一级A标准。     

PACT-A/O工艺处理尼龙66化工废水

采用PACT-A/O工艺处理神马尼龙化工公司尼龙66化工废水。运行结果表明:在进水COD和NH3-N平均浓度分别为1237.02mg/L、60.33mg/L时,去除率分别为90.9%和67.66%,出水COD和NH3-N浓度分别可达到112.53mg/L和19.51mg/L,均达到排放标准;并且系统的抗冲击负荷能力强,污泥沉淀性能及二沉池剩余污泥的脱水性能良好,进行机械脱水时无需投加调质的化学药剂。     

水解酸化-两级厌氧工艺处理高浓度甲醇废水

采用水解酸化-两级厌氧工艺处理高浓度甲醇废水,结果表明:该工艺具有良好的处理效能,当进水COD在7000～11000mg/L时,出水COD浓度可降低到600mg/L以下;两级厌氧系统总的COD去除率可达到90%～92.5%;同时该工艺具有启动速度快,耐冲击负荷能力强的特点。     

水解酸化预处理颜料企业废水实验研究

针对鞍山某颜料生产企业实际生产废水,通过微生物驯化、水解酸化实验,验证了水解酸化预处理该废水的可行性。通过考察处理过程中COD、B/C、pH、NH3-N等监测指标随反应时间的变化,获得了处理该实际废水的最优条件:MLSS=4 500~5 000 mg/L,pH=6.5~7.5及HRT=24 h,COD去除率为31.1%,B/C从0.18升至0.69,可生化性明显增加。为该企业内部废水处理厂设计、工艺参数选取提供了基础数据。     

UASB+A/O+BAF处理高浓度氨氮废水

在丙烯酰胺生产过程中产生的高浓度氨氮有机废水,采用UASB+A/O+BAF组合工艺处理该废水。结果表明:系统稳定运行后,在进水COD浓度为3 800～4 600 mg/L,NH3-N浓度为390～520 mg/L时,COD、NH3-N去除率分别达到98.2%和96.4%,出水各项指标均达到GB 8978—1996《污水综合排放标准》二级标准。     

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

ＲｅｍｏｖａｌｏｆｈｅａｖｙｍｅｔａｌｓｆｒｏｍｓｅｗａｇｅｓｌｕｄｇｅｂｙｌｏｗｃｏｓｔｉｎｇｃｈｅｍｉｃａｌｍｅｔｈｏｄａｎｄｒｅｃｙｃｌｉｎｇｉｎａｇｒｉｃｕｌｔｕｒｅＷｕＱｉｔａｎｇ，ＮｙｉｒａｎｄｅｇｅＰａｓｃａｓｉｅ，ＭｏＣｅｈｕｉＦ...     

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.