接种物浓度和负荷对餐厨垃圾消化性能及产气动力学的影响

为探析接种物浓度(Biomass concentration,BC)和负荷(Organic loading rate,OLR)对餐厨垃圾厌氧消化性能及产气动力学的影响,在中温批次厌氧消化反应器中进行BC和OLR梯度试验,采用理化分析探析各反应器的性能参数,并采用一阶模型和modified Gompertze模型评价各反应器的产气动力学特征.试验结果表明,超负荷会降低反应器运行效率,影响过程稳定性,而提高BC可以减少单位细胞承受的有机负荷,有利于优化厌氧消化过程.产甲烷阶段是餐厨垃圾厌氧消化的限速步骤,各实验条件下水解速率常数(k)始终大于产甲烷速率常数(R_m').OLR和BC对k和R_m'的影响是波动的,从两个参数的数值上无法判断反应器的稳定性.相比之下,高效运行的反应器k/R_m'保持在(2.54±0.62),k/R_m'随OLR的增加及BC的下降单调递增,而随着k/R_m'增加,反应器运行效率下降.这从反应动力学上证实了增加OLR会加剧产酸和耗酸过程的不匹配,引起反应器失稳;而提高的BC浓度有利于缓解这种失衡,对保证反应器的过程稳定具有重要意义.     

施氮对小麦硒(Ⅵ)吸收、转运和分配的影响

为揭示施氮对小麦硒吸收,转运和分配的影响,通过合理施氮提高小麦硒的利用效率提供理论参考,本研究通过盆栽试验,设置Se1(0.74 mg·kg~(-1))和Se2(2.60 mg·kg~(-1))两个硒酸盐处理;每个硒水平又设为N1(100 mg·kg~(-1))和N2(200mg·kg~(-1))两个氮水平,分别测定了小麦拔节期和成熟期各器官生物量及硒含量.结果表明,升高氮水平使Se1和Se2处理小麦籽粒产量分别提高了13.2%和24.0%.与氮素施用量无关,升高外源硒水平能显著提高小麦各器官中硒含量(P0.01),且以N1处理时效果更显著;Se1处理升高氮水平对小麦硒吸收的促进作用大于Se2处理,Se1和Se2处理升高氮水平使得小麦籽粒硒含量分别提高了22.6%和12.1%.各器官中硒总量占植株硒总量的百分比的大小顺序与富集系数相同,依次为茎叶籽粒颖壳根,升高氮水平促进了小麦根部对硒的吸收和富集,以及营养生长阶段硒向地上部的运移,并使Se1和Se2处理小麦籽粒中的硒总量占植株硒总量的百分比分别提高了11.1%(P0.05)和25.9%(P0.05).因此,施用氮肥可以调控硒的有效性,缺硒地区合理升高氮水平提高了小麦产量及硒含量,而在富硒或硒中毒地区合理施氮肥可缓解硒对小麦的毒害作用.     

异味污染评价与治理研究进展

本文对国内外异味污染评价技术,包括异味污染评价指标、采样技术和测定方法、异味污染预测模型以及异味间相互作用进行了综述,同时对异味污染治理技术进行了简要介绍.     

An optimization approach for sustainable release of e-flows for lake restoration and preservation: Model development and a case study of Baiyangdian Lake, China

In this paper, we describe the development of a model for the sustainable release of e-flows from the regional water resource infrastructure (e.g., reservoirs, rivers with available water) for lake restoration and preservation, and use the model in a case study of Baiyangdian Lake, China. First, we define the sustainable environmental flows (e-flows), with an emphasis on the ecological importance of temporal variation in factors such as water level (depth). By analyzing historical data on the suitable range of water levels in the lake, we evaluated fluctuations using canonical correspondence analysis and frequency distribution analysis. The temporal variations required by the ecosystem of the lake were also assessed. Based on this approach, we developed an optimization model for sustainable release of e-flows. We used the adaptive genetic algorithm approach to solve the model and determine the required release of e-flows. Scenario analysis then provided a range of potential management strategies for the e-flows. The optimal results are helpful to the lake managers to establish sustainable e-flow release schemes for the lake restoration and preservation.     

A flounder (Paralichthys olivaceus) gill cell line as in vitro acute assay system of nonylphenol cytotoxicity

A cell line (FG cells) derived from a gill of the flounder, Paralichthys olivaceus were used to determine the cytotoxic effects of nonylphenol (NP). Cytotoxicity was measured by three endpoint systems: neutral red (NR) uptake assay, methyl thiazolyl tetrazolium (MTT) assay and cell protein assay. The result showed that NP was cytotoxic to FG cells at all tested concentrations, and toxicity increased as the concentration of NP was progressively increased. The 24 h-IC₅₀ values of NP were 39.81, 37.76 and 38.22 ??mol/L for NR uptake, MTT assay and cell protein assay, respectively. Moreover, the morphological changes of FG cells were also studied at the concentration of 30 ??mol/L for 24 h. Cells morphology were markedly altered by NP observed under a scanning electron microscopy, as evidenced by swelling cells, two and more nucleolus and an increased number of lipid particles. This would suggest that the FG cell line is a suitable bioindicator for the screening of the acute toxicity of NP.     

自动监测设备比对监测合格率统计方法的探讨

参照污染源达标率统计方法,得出自动监测设备比对监测的合格率统计方法,并具体介绍了企业单个项目合格率统计方法、区域单个项目合格率统计方法和区域综合合格率统计方法。     

微丝菌(Microthrix parvicella)原位荧光杂交(FISH)定量过程的条件优化

微丝菌(Microthrix parvicella)是世界范围内诱发活性污泥膨胀现象的主要丝状菌之一,它在活性污泥中准确的原位定量解析对污泥膨胀现象及控制策略研究具有非常重要的意义.由于微丝菌自身的特殊生理生化性质(如表面高疏水性及较厚细胞壁)易导致常规荧光原位杂交(FISH)过程中定量结果偏低.本研究针对FISH过程中存在的探针渗透率低、荧光信号偏弱等现象,从活性污泥样品前处理、杂交过程条件等方面对Microthrix parvicella的FISH定量过程进行了优化.结果表明,在前处理使用溶菌酶(浓度为36 000 U·m L~(-1)),探针浓度为4.5 ng·μL~(-1),杂交时间延长至4 h的条件下,Microthrix parvicella的FISH定量结果可从1.12%提高至96.70%,并与定量PCR(q-PCR)结果和EikelboomJenkins法(镜检观察)定量结果更为趋近一致.     

石油降解菌群构建的研究

本实验通过初步有序组合方法将筛选得到的原油降解菌株A5、A6、YA5、YA6,十六烷降解菌株B3、YB3,萘降解菌株C3、YC3,石蜡降解菌株及产表面活性剂菌株D4共9株优良菌株进行组合后分别做液态原油降解实验,排除拮抗效应,优化互生效应,结果发现A5、YB3、YC3、D4配伍组合为最佳组合方案,此时的原油降解率达到58.6%,然后再通过正交法确定这四种菌株的配比,结果发现当A5:YB3:YC3:D4为0.5:1:0.1:0.5时对原油的降解效率最高为61.3%。     

深圳大鹏湾海域表层沉积物和生物体中多环芳烃残留及其风险评价

为了研究深圳大鹏湾海域沉积物和生物体中多环芳烃的污染状况,2011年10月在大鹏湾采集表层沉积物及鱼类、虾类和贝类等生物样品,采用气相色谱-质谱法(GC-MS)分析了16种优先控制多环芳烃(PAHs)的含量.结果表明,大鹏湾海域表层沉积物和生物样品中PAHs总量范围分别为216.56~1 314.92 ng·g-1(干重,下同)和70.88~251.90 ng·g-1(湿重,下同);生物样品按平均含量计,鱼类最高(171.52 ng·g-1),贝类次之(134.75 ng·g-1),虾类最低(123.35 ng·g-1).与全球其他海域相比,大鹏湾海域表层沉积物和生物体PAHs污染处于中等水平.沉积物中PAHs的组成以4环为主,来源分析表明该海域PAHs污染主要来源于化石燃料燃烧源和石油污染源的共同输入.生物体中PAHs主要为2~3环PAHs,这与其生活习性和污染物的生物可利用性等因素有关.风险评价表明,大鹏湾表层沉积物中的PAHs在一定程度上可能会对该海域生物产生不利影响;生物样品PAHs的苯并(a)芘等效浓度值相对较高,长期食用这些水产品可能会有潜在的健康风险.     

人工湿地植物对高盐废水中COD的去除作用

针对经生化处理的石油和精细化工工业区的工业废水盐含量较高、氮磷营养盐含量较低和COD含量较高的特点,构建了高盐度进水条件下表面流人工湿地的中试试验装置,考察了水葱、芦苇和香蒲在此类高盐废水中的生长状况,比较了三种植物混合试验单元与无植物试验单元对此类高盐废水中COD的去除效果,研究了高含盐量工业废水湿地系统内植物生长对微生物量的影响,以及植物在微生物去除COD过程中的作用。结果表明,高含盐量的工业废水对水葱、芦苇和香蒲的生长有一定的抑制作用,植物单元对工业废水中有机物的净化效果明显好于无植物单元,且植物生长越好,人工湿地内水体中的COD净化效果越好。混合植物单元对高含盐量工业废水中COD的总去除量约为无植物单元的4倍,证明植物的存在可以增强湿地单元内土壤微生物对有机物的去除能力。