1株脱氮除磷菌的筛选及其特性研究

采用YG培养基,结合蓝白斑筛选、异染粒染色及好氧除磷能力检测等实验,从城市生活污水处理厂好氧生化池的活性污泥中分离出7株好氧除磷菌;再经硝酸盐还原产气和缺氧培养实验,筛选出1株高效脱氮除磷菌;通过16S rRNA基因同源性比较和生理生化鉴定,初步将其鉴定为Pseudomonas grimontii,命名为C18.菌株C18在好氧培养24h后,培养基中上清液磷浓度从38.7mg/L降低到2.28mg/L,除磷率达94.1%.C18在缺氧培养24h后,培养基中上清液磷浓度从44.5mg/L降低到5.21mg/L,除磷率达88.3%;上清液硝酸盐氮浓度从184.2mg/L降低到30.6mg/L,脱氮率达83.4%.菌株C18最适脱氮除磷温度为30℃;最适脱氮除磷pH为7.5.     

碳源变化对降解2,4-D的好氧颗粒污泥性能及形态的影响

在长期运行的序批式生物反应器(SBR)中,考察了以葡萄糖和2,4-二氯苯氧乙酸(2,4-D)为混合碳源培养的好氧颗粒污泥在转换为2,4-D唯一碳源废水后,其形态、结构及对目标污染物去除功能的变化.结果表明,基质转换为2,4-D单一碳源后,好氧颗粒污泥仍保持了对目标污染物高效的去除能力.当进水2,4-D浓度为361～564mg/L,其去除率为99.2%～100%,COD平均去除率达到85.6%.混合碳源向2,4-D单一碳源转换对原好氧颗粒结构产生一定破坏作用,使其发生部分解体,粒径由513μm下降到302μm.但好氧颗粒污泥良好的耐负荷冲击使其保持了颗粒主体,通过一段时间适应调整后能够重新聚集生长,最终获得能够利用2,4-D为唯一碳源生长并具有良好沉降性(SVI20～40mL/g)的好氧颗粒污泥,粒径为489μm.扫描电子显微镜(SEM)观察结果表明,混合碳源转向单一碳源使好氧颗粒生物相丰富度降低.     

焦化废水处理工程调试运行研究

针对焦化废水处理调试运行存在的问题,以实际运行中的焦化废水处理工程为例,介绍了其调试运行过程.指出焦化废水调试及稳定运行的控制要点,并提出调试运行过程中可能出现的问题及解决措施,为同类废水的调试和运行提供参考.     

Effects of Cu（Ⅱ） and humic acid on atrazine photodegradation

This work was designed to explore the characteristics of photodegradation of herbicides in the copper-polluted water body. The results showed that Cu(II) alone could induce a photo Fenton-like reaction to enhance the degradation of atrazine, in which hydroxyl radical ( OH) was a main active species. Humic acids restrained atrazine degradation, nevertheless, when introducing Cu(II), the photodegradation was accelerated, in which singlet oxygen (1O2) replaced OH acting as the prevailing species. A feasible mechanism for the photochemical process was also proposed, which is helpful for better understanding the environmental photochemistry of atrazine in the copper-polluted water.     

Methanotrophic community structure of aged refuse and its capability for methane bio-oxidation

Aged refuse from waste landfills closed for eight years was examined and found to contain rich methanotrophs capable of biooxidation for methane. Specially, community structure and methane oxidation capability of methanotrophs in the aged refuse were studied. The amount of methanotrophs ranged 61.97 103–632.91 103 cells/g (in dry basis) in aged refuse from Shanghai Laogang Landfill. Type I and II methanotrophs were found in the aged refuse in the presence of sterilized sewage sludge and only Type I methanotrophs were detected in the presence of nitrate minimal salt medium (NMS). The clone sequences of the pmoA gene obtained from the aged refuse were similar to the pmoA gene of Methylobacter, Methylocaldum, and Methylocystis, and two clones were distinct with known genera of Type I methanotrophs according to phylogenetic analysis. Aged refuse enriched with NMS was used for methane biological oxidation and over 93% conversions were obtained.     

Efficacy of natural biocide on control of microbial induced corrosion in oil pipelines mediated by Desulfovibrio vulgaris and Desulfovibrio gigas

We compared the efficacy of a natural biocide with four chemical tetrakishydroxymethyl phosphonium sulfonate, benzyl trimethyl ammonium chloride, and formaldehyde, glutaraldehyde, to control microbial induced corrosion in oil pipelines. The efficacy of biocides were monitored against Desulfovibrio vulgaris and Desulfovibrio gigas in experimental pipes by measuring cell counts, H2S production, Fe(II) production, production of extracellular polymeric substances and structure of biofilm. The treatment with cow urine had minimum planktonic cell counts of 3 102 CFU/mL as well as biofilm cell counts of 9 101 CFU/mL as compared with tetrakishydroxyl methyl phosphonium sulfonate, benzyl trimethyl ammonium chloride, formaldehyde and glutaraldehyde. Sulfide production was the lowest with cow urine (0.08 mmol/L), followed by tetrakishydroxymethyl phosphonium sulfonate 0.72 mmol/L. On day 90 of treatment, Fe(II) production was also found to be the lowest with cow urine. The scanning electron microscopic studies indicated that the biofilm bacteria were killed by cow urine. These results demonstrate the cow urine mediated control of microbially induced corrosion, and this is indicative of its potential as a viable substitute of toxic biocides. To the best of our knowledge, this seems to be the first report which screens possible biocidal activity by cow urine as compared to the most common biocides which oil industry is currently using.     

Effect of C/N ratio, aeration rate and moisture content on ammonia and greenhouse gas emission during the composting

Gaseous emission (N₂O, CH₄ and NH₃) from composting can be an important source of anthropogenic greenhouse gas and air pollution. A laboratory scale orthogonal experiment was conducted to estimate the effects of C/N ratio, aeration rate and initial moisture content on gaseous emission during the composting of pig faeces from Chinese Ganqinfen system. The results showed that about 23.9% to 45.6% of total organic carbon (TOC) was lost in the form of CO₂ and 0.8% to 7.5% of TOC emitted as CH₄. Most of the nitrogen was lost in the form of NH₃, which account for 9.6% to 32.4% of initial nitrogen. N₂O was also an important way of nitrogen losses and 1.5% to 7.3% of initial total nitrogen was lost as it. Statistic analysis showed that the aeration rate is the most important factor which could affect the NH₃ (p = 0.0189), CH₄ (p = 0.0113) and N₂O (p = 0.0493) emissions significantly. Higher aeration rates reduce the CH₄ emission but increase the NH₃ and N₂O losses. C/N ratio could affect the NH₃ (p = 0.0442) and CH₄ (p = 0.0246) emissions significantly, but not the N₂O. Lower C/N ratio caused higher NH₃ and CH₄ emissions. The initial moisture content can not influence the gaseous emission significantly. Most treatments were matured after 37 days, except a trial with high moisture content and a low C/N ratio.     

Preliminary report on methane emissions from the Three Gorges Reservoir in the summer drainage period

Considerable variations may exist in CH4 emissions from the Three Gorges Reservoir.     

响应面法优化复合微生物吸附剂对低浓度Cr3+的吸附

根据已有4种微生物吸附剂的吸附基团存在的差异特征,将其复配成复合吸附剂,借助统计学方法研究其对低ρ(Cr3+)废水的吸附性能.在单因素试验基础上,利用P-B(Plackett-Burman)法筛选出吸附过程4个主要影响因素分别为pH,初始ρ(Cr3+)及微生物吸附剂XB和TQ的投加量,应用最陡爬坡试验接近主要因素最优水平,采用Box-Behnken试验设计和响应面分析得到对低浓度Cr3+吸附过程的二阶模型.结果表明,最优吸附条件为pH 4.0,初始ρ(Cr3+)为4.86mg/L,XB和TQ的投加量分别为0.20和0.13 g/L,实际吸附率达到87.54%,与理论预测值(87.68%)接近,且高出单一吸附剂吸附率7.79%～17.35%.FT-IR扫描显示,复合微生物吸附剂性能提高与表面基团增多有关.通过响应面分析法优化复合微生物吸附,吸附性能明显提高.     

基于服务式GIS的流域水质目标管理技术平台架构设计

针对流域水质目标管理与GIS集成技术,对比分析传统模式与服务式GIS模式的优劣,提出了基于服务式GIS的流域水质目标管理技术平台的层次结构、总体架构及建设步骤;基于具体建设需求分析,构建了辽河流域水质目标管理技术平台的详细架构。