粉煤灰对印染废水的吸附处理研究

研究了粉煤灰对印染废水吸附脱色处理效果,确定了最佳脱色条件和穿透曲线的特征,并探讨了其对印染废水CODcr的去除率。结果表明：对色度都为700倍、CODcr分别为664.2 mg/L、947.1 mg/L的红、蓝色印染废水,粉煤灰处理的最佳用量分别为18 g和16 g,最佳吸附接触时间分别为2.0 h和2.5 h,最佳pH5－7,穿透体积分别为115 mL和120 mL,脱色率均可达到95（以上;CODcr的去除率分别为81.5%和41.1%。     

铁炭微电解法在印染废水处理中的研究

采用铁炭微电解法对印染废水进行顸处理,对影响铁炭微电解效率及LCOD、色度去除率的各种因素进行了研究。结果表明：铁炭微电解法预处理印染废水的最佳初始pH值为3,最佳混凝pH值为7．5,最佳铁炭比为1：1．1,铁屑的最佳投加浓度为10．8g／L,适宜的反应时间为30min,COD去除率最高可达38．2％,色度的去除率大于95％;通过铁炭微电解预处理后的印染废水其可生化性明显提高,BOD／COD比由0．16提高到0．45,为后续的生物处理提供了有利的条件。     

UASB厌氧反应器预处理印染废水的中试研究

对厌氧上流式反应器(UASB)预处理难降解印染废水进行了中试研究。结果表明,厌氧上流式反应器稳定运行2个多月,在进水COD波动较大的情况下(最高1020.0mg/L,最低593.6mg/L,平均755.4mg/L),厌氧上流式反应器出水平均COD409.3mg/L,平均去除率为45.5%。厌氧上流式反应器对色度去除效果较佳,进水平均色度342倍,出水平均色度78倍,平均去除率为77.2%。印染废水B/C由0.29提高到0.46,提高了0.17,废水可生化性明显改善。     

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.     

HCR技术在印染废水处理改造中的应用

通过对某印染公司原有设施的改造,把HCR技术应用在废水改造中。进水量为11000m3/d,COD2200～2500mg/L,pH12左右,色度600～800倍,改造后运行稳定,废水处理效果有大幅提高,出水COD为360mg/L、色度为300倍均能达标排放,其去除率分别为86%、50%。     

利用粉煤灰处理造纸中段废水的实验研究

采用保定热电厂粉煤灰处理某小型造纸厂中段废水,考察了粉煤灰处理造纸中段废水的效果,结果表明废水pH值为12、灰水接触时间为2h、原水COD(浓度为1200mg/L)稀释3、水灰比15:1、粉煤灰粒径71～100μm,粉煤灰含碳量为15%时,造纸中段废水中COD的去除率可达到76.2%～89.7%.     

电化腐蚀－还原降解－混凝吸附法处理印染废水的研究

为了处理印染废水,介绍一种以铁屑、烟道灰或瓦斯灰为处理剂的新方法,探讨了处理机理,给出了适宜的处理条件和工艺流程。实验结果表明,当处理剂用量比在4：6左右,铁屑过滤和混凝吸附的pH值分别控制在4～5和8～9时,处理20min,经处理后的印染废水,COD去除率和脱色率均可达90％以上,出水COD全部低于100mg/L,水质清澈透明,各项水质指标均符合国家排放标准。该法适用于中小型纺织印染厂的废水治理。     

基于活性炭纤维处理印染废水方法优选

印染废水是当前工业废水处理的难点,污染物质主要来自各种染料、化学药剂等,具有污染浓度高、色度大、水质变化大等特点。分别用生物活性炭纤维法、活性污泥-生物活性炭纤维联合法处理印染废水,并对两种方法的处理效果进行比较。试验结果表明,活性污泥-生物活性炭纤维联合法处理印染废水,COD去除率为94.3%,色度值降至40倍,悬浮物浓度降至40 mg/L,氨氮浓度降至2.2 mg/L;生物活性炭纤维法处理印染废水,COD去除率为86.0%,色度值降至520倍,悬浮物浓度降至240 mg/L,氨氮浓度降至1.5 mg/L。活性污泥-生物活性炭纤维联合法对废水COD、色度、悬浮物的处理效果优于生物活性炭纤维法。     

优势菌强化印染废水脱色及污染物降解研究

以曝气生物滤池为核心工艺研究优势菌强化印染废水脱色及污染物降解。从印染废水处理厂活性污泥中分离得到染料脱色菌15株、苯胺降解菌2株、印染助剂降解菌10株。试验进水平均色度为400倍,平均COD浓度为1295mg/L,厌氧段以组合填料为载体,水力停留时间10h,菌种投加量为0.2%;好氧段以煤渣填料为载体,水力停留时间25h,菌种投加量为0.1%。结果表明:系统连续进出水一周以后出水COD浓度稳定在130¹10mg/L,平均浓度为118 mg/L,去除率90.9%;出水色度在40倍左右,去除率90%;出水苯胺浓度低于4mg/L。     

物化＋生化处理印染废水

文章介绍了物化＋生化处理工艺在印染废水中的应用。运行结果表明,当进水BOD5为250-400mg／L,COD为800-1100mg／L时,出水达到《江苏省纺织染整工业水污染物排放标准》（DB32／670—2004）一级标准。该工艺具有适应性强、运行稳定、有机物及色度去除率高等特点,因此在印染废水处理中具有良好的前景。     

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.     

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.     

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

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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.     

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.     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.