钼酸铵工业废气、废水综合治理技术开发与应用

以钼酸铵厂产生的废气和废水综合治理技术的开发应用实例,采用酸性生产废水吸收含氨废气,NH3去除率达95%;将高浓度含氨废水通过汽提工艺处理,NH4+-N去除率达到99.99%,达标排放。     

生化法处理煤气废水的工艺选择及中试研究

通过对三种生化工艺处理处理煤气废水的比较,确定了水解酸化-好氧两段生物法处理煤气废水,并对该工艺进行了中试实验研究,实验结果表明,在进水COD＜2500mg/L,NH3-N＜150mg/L时,COD去除率可达到80%,NH3-N去除率可达到50%,BOD去除率在96%以上.     

铵饱和天然钙型沸石基质人工湿地对模拟养猪废水的处理效能

针对养猪废水中有机污染物和氨氮(NH4+-N)浓度高、悬浮物含量高的特点,采用循环流人工湿地工艺对其进行处理,研究以天然钙型沸石为基质的人工湿地对模拟养猪废水的处理效能。结果表明:历时22个月的高NH4+-N负荷运行,已使人工湿地中的钙型沸石对NH4+-N的吸附达到饱和。在天然钙型沸石填料铵饱和条件下,湿地系统对模拟养猪废水中NH4+-N的处理效果仍可达61%~76%,对TN的去除率可达66%~80%,对CODCr的去除率一直维持在78%~92%之间。     

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。     

微电解-电/Fenton-曝气池工艺预处理高浓度亚麻废水

高浓度亚麻废水不宜直接进行生化处理。试验采用"Fe-C柱微电解-电/Fenton-曝气池"工艺对其进行预处理,即先采用Fe/C微电解,然后基于Fe2+的生成几乎同步引入电/Fenton反应,之后再调节流出液pH至碱性并鼓入空气以除去部分NH3-N。相应优化工艺条件为:Fe/C柱微电解时mFe/mC为2:1,废水停留时间为1.5 h;电/Fenton时双氧水(30%)滴加速度为0.025 mL/min;调节水样pH10并在空气流速为1.5 L/min的条件下空气吹脱1.5 h。采用该工艺预处理高浓度亚麻废水后,出水几乎为无色;固体悬浮物的去除率可达94.2%,NH3-N去除率可达71.4%,COD去除率可达51.8%,BOD5去除率可达28.3%,为后续生化深度处理创造了有利条件;BOD5/COD值由原来的0.12上升至0.19,废水的可生化性得到较明显的改善。电/Fenton反应的处理效果好于普通的Fenton反应,其原因可能是由于电/Fenton既有"原位"的均相/非均相Fenton反应发生,又有在微电解电场协助下的"电催化Fenton"反应发生。     

IC＋A/O＋BIOFOR处理高浓度有机废水工程实例

江西某生物化工有限公司在生产乳酸的过程中产生大量高浓度有机废水,采用IC＋A/O＋BIOFOR联合工艺进行处理。当进水ρ（COD）平均为5 483 mg/L,ρ（NH3-N）平均为97.83 mg/L时,出水ρ（COD）平均为84 mg/L,去除率达98%;出水ρ（NH3-N）平均为12.07 mg/L,去除率为88%...     

去除焦化废水中COD、NH_3-N的生物处理技术

在焦化废水生物处理技术各种工艺中 ,A1-A2 -O工艺是比较好的一种 ;采用高效反应器—生物流化床技术提高微生物浓度并选用特殊菌种可提高焦化废水中COD、NH3-N去除率。影响焦化废水COD、NH3-N去除效率有多种因素。在实际工程应用中该工艺处理焦化废水的成本低于 3 5元 /吨。     

光合细菌两段流化床处理鸡粪粪水的研究

光合细菌对高浓度有机废水具有较好的适应性和处理能力,特别是作为一个预处理工艺对后续污水处理可以产生重要的影响。鉴于光合细菌生长时间相对较长,为提高光合细菌对高浓度有机污水的处理效率,本研究利用光合细菌两段流化床反应器对鸡粪粪水进行降解。试验结果表明:经过60 d的启动运行后,反应器进入稳定状态,在进水pH值6.0,COD小于10000mg/L范围内,流化床水力停留时间(HRT)为48 h时,对废水COD去除率为88.10%,TN去除率为68.29%,NH3-N去除率为94.42%,NO3-N去除率为65.43%。     

气浮／生化工艺在炼油废水中的应用

通过对石油化工企业炼油废水水质特性的分析,采用隔油一浮选一曝气-A／0生化工艺处理锦西石化的炼油废水。实践表明,二级气浮＋二段生化处理工艺对炼油废水COD和NH3-N的平均去除率为96．7％和99．2％。使外排水水质远优于辽宁省《污水综合排放标准》中规定的CODcr〈50,NH3-N〈8的标准。     

催化氧化-A/O工艺-生物滤池处理高浓度有机胺废水中试

试验采用催化氧化-A/O工艺-生物滤池组合工艺,以高浓度有机胺废水为研究对象,重点考察了该工艺对进水COD、氨氮和总氮的去除效果。结果表明:采用催化氧化预处理工艺,能有效降低废水中的抑制性物质,提高废水的B/C;A/O工艺能去除大量的有机物和总氮,但出水氨氮有所升高;末端采用生物滤池处理该废水,能有效降低废水中的氨氮和COD。当进水ρ(COD)为3 000～4 000 mg/L、ρ(NH3-N)为15～60 mg/L、ρ(TN)为350～450 mg/L时,出水水质可达当地环保要求的排放标准:ρ(COD)≤300 mg/L、ρ(NH3-N)≤35mg/L,表明该工艺可应用于高浓度有机胺废水的处理。     

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.     

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.     

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.     

Effect of sorbed and desorbed Zn(Ⅱ) on the growth of a green alga (Chlorella pyrenoidosa)

Toxic effect of Zn(Ⅱ) on a green alga (Chlorella pyrenoidasa) in the presence of sepiolite and kaolinite was investigated.The Zn-free clays were found to have a negative impact on the growth of C.pyrenoidosa in comparison with control samples (without adding any clay or Zn(Ⅱ)).When Zn(Ⅱ) was added,the algae in the presence of clays could be better survived than the control samples,which was actually caused by a decrease in Zn(Ⅱ) concentration in the solution owing to the adsorption of Zn(Ⅱ) on the clays.When the solution system was diluted,the growth of algae could be further inhibited as compared to that in a system which had the same initial Zn(Ⅱ) concentration as in the diluted system.This in fact resulted from desorption of Zn(Ⅱ) from the zinc-contaminated clays,although the effect varied according to the different desorption capabilities of sepiolite and kaolinite.Therefore the adsorption and desorption processes of Zn(Ⅱ) played an important part in its toxicity,and adsorption and desorption of pollutants on soils/sediments should be well considered in natural eco-environmental systems before their risk of toxicity to aquatic organisms was assessed objectively.