T-RFLP方法分析城市污水处理厂中细菌群落的动态变化

采用基于16SrRNA基因的末端限制性片段长度多态性技术(T-RFLP),分析了功能稳定的2个城市污水处理系统中(系统A及系统B),细菌群落结构在105d中的动态变化.在研究中,系统A和系统B功能稳定,BOD出水浓度均在8mg/L左右,总氮(TN)出水浓度分别在25mg/L和23mg/L之下.T-RFLP图谱分析表明,系统A中,115、118、123、471、482和835bp等T-RFs的相对丰度变化显著,系统B中,123、471、750和835bp等T-RFs的相对丰度变化显著.移动窗口分析表明,系统A中细菌群落的平均变化率Δt(15d)为21.5%±5.7%,系统B的平均变化率Δt(15d)为22.6%±5.0%.洛伦兹曲线分析表明,系统A中20%的微生物的累积相对丰度为43%～50%;系统B中20%的微生物的累积相对丰度为47%～52%.结果表明,在城市污水处理厂中,稳定的功能并没有藕联着稳定的细菌群落结构.     

浅谈区域开发环境影响评价存在的主要问题与对策

分析了目前区域开发环境影响评价（REA）还存在的主要问题：进行环境影响评价的开发区域少,且其环境评价介入时间晚;理论体系尚未建立;应用研究不足;公众参与力度不够;专业人才不足。提出了建立健全法律法规、加强科研力度、加大投资、加强国际交流与合作、强化公众参与力度、加大人才的培养与引进等建议。     

班组安全自主管理

班组管理是企业一切工作的基础。企业若想真正做到"安全第一,预防为主",最终要落实到班组安全管理上。没有班组的安全自主管理,就谈不上企业的安全自主管理。如何实施班组安全自主管理?关键是要设立好班组安全管理持续改善的目标,利用好班组的现有资源及外部资源,落实对策,在实施改善的过程中进行目标诊断,对改善的结果进行确认,并提出下一步改善目标,形成PDCA循环。     

基于GIS的油品储罐区风险评价及应急资源优化调运系统

为对油品储罐区事故进行迅速的风险评价和应急救援,在详细分析油品储罐区危险特性的基础上,建立了区域风险评价模型、应急资源优化调运模型和实时在线应急培训模型,将其作为功能模块与GIS技术加以整合,构建了基于GIS的油品储罐区风险评价及应急资源优化调运系统.当油品储罐区发生突发事件后,针对不同的事故类型和事故级别,该系统可对其区域风险进行评估,划分不同伤害等级范围,并在最短的时间内,通过带有"单程最大运输能力"约束的两目标连续消耗应急资源优化调运模型计算,给出合理有效的应急资源优化调运方案.无事故发生时,也可进行相应的事故模拟演练及实时在线应急培训.在西部管道油品储罐区的实例应用表明,该系统可为油品储罐区制定应急救援活动方案,提高危害防护水平提供技术支撑.     

裂隙对雾龙洞岩溶发育及地下径流的影响分析

尝试利用裂隙测量结果探究区域岩溶发育规律。采用统计窗口法对湖北鄂西地区雾龙洞岩溶流域的碳酸盐岩地层进行了大量的裂隙测量,分析了流域内裂隙发育的情况,研究了裂隙的几何参数——倾向、倾角、隙宽、线密度、面裂隙率等在不同层位、不同裂隙分组内的变化情况;结合构造、岩溶洼地发育方向、洞穴野外探测结果,综合分析了裂隙发育对本区岩溶发育的影响;运用渗透张量理论对岩溶流域裂隙的各向异性和非均质性进行了研究,并分析了雾龙洞岩溶流域地下水的主要渗流方向形成的原因,对查明雾龙洞岩溶流域岩溶发育规律以及地下水的运移、赋存规律具有一定的指导作用。     

1，4-二氯苯降解菌的分离及其降解特性研究

从某污水处理曝气池的活性污泥中分离出一株能够以1,4-二氯苯为唯一碳源和能源生长的菌株DEB-1,通过形态特征和生理生化试验初步鉴定为黄杆菌属（Flavobacterium sp.）。实验结果表明,该菌株最适降解温度为32℃、最适降解pH为7.8,24 h对100 mg/L的1,4-二氯苯的降解率达94.5%。菌株DEB-1的降解谱较广,对5种氯苯类物质具有较高的降解率。并进一步研究了DEB-1的1,4-二氯苯降解酶粗酶液的性质,其最适反应温度和pH分别为30℃和8.5。对处理含氯代芳香化合物的有机废水具有一定的意义。     

Alkali borosilicate glass by fly ash from a coal-fired power plant

The possibility of using coal fly ash as a silica source for alkali borosilicate glass was investigated. Alkali borosilicate glasses were prepared from the coal fly ash mixed with 30 wt.% reagents composed of Na(2)O and B(2)O(3) by susceptor-induction heating. Their densities ranged from 2.24 to 2.55 g cm(-3) and decreased as the amount of B(2)O(3) addition increased. However, the Vickers microhardness showed a different tendency with the density since the glass network connectivity improved by boron anomaly, which was identified by a nuclear magnetic resonance analysis. The Vickers microhardness of the glass product, with the addition of 15 wt.% B(2)O(3) and 15 wt.% Na(2)O, was about 4030 MPa. Furthermore, the changes in microstructure were consistent with those in the chemical stability by the toxicity characteristic leaching procedure (TCLP).     

Determination of partition and diffusion coefficients of formaldehyde in selected building materials and impact of relative humidity

The partition and effective diffusion coefficients of formaldehyde were measured for three materials (conventional gypsum wallboard, "green" gypsum wallboard, and "green" carpet) under three relative humidity (RH) conditions (20%, 50%, and 70% RH). The "green" materials contained recycled materials and were friendly to environment. A dynamic dual-chamber test method was used. Results showed that a higher relative humidity led to a larger effective diffusion coefficient for two kinds of wallboards and carpet. The carpet was also found to be very permeable resulting in an effective diffusion coefficient at the same order of magnitude with the formaldehyde diffusion coefficient in air. The partition coefficient (K(ma)) of formaldehyde in conventional wallboard was 1.52 times larger at 50% RH than at 20% RH, whereas it decreased slightly from 50% to 70% RH, presumably due to the combined effects of water solubility of formaldehyde and micro-pore blocking by condensed moisture at the high RH level. The partition coefficient of formaldehyde increased slightly with the increase of relative humidity in "green" wallboard and "green" carpet. At the same relative humidity level, the "green" wallboard had larger partition coefficient and effective diffusion coefficient than the conventional wallboard, presumably due to the micro-pore structure differences between the two materials. The data generated could be used to assess the sorption effects of formaldehyde on building materials and to evaluate its impact on the formaldehyde concentration in buildings.     

跨海大桥主墩桩基钢护筒腐蚀损伤识别

跨海大桥主墩桩基施工过程中采用的钢护筒被保留作为桩基的外层,容易受到海洋环境的腐蚀破坏。提出一种基于插值曲率模态指纹库比对的桩基损伤识别方法,为解决测试数据不完备的问题,采用三次样条函数几何插值得到扩展后的桩基振型,然后在扩展振型的基础上采用中心差分计算得到曲率模态指标。以金塘大桥为工程背景,建立索塔-基础多尺度有限元模型,考虑海水腐蚀造成桩基钢护筒局部损失情况,以损失减薄区域的位置、轴向长度、深度为损伤参数,设置多种损伤工况样本,计算并建立基于插值曲率模态的桩基损伤识别指纹库,最后通过指纹库以外损伤工况与库内样本比对的方式,验证损伤识别效果。研究表明,为保证三次样条函数几何插值得到扩展振型对真实振型的拟合精度,至少需要沿桩基均布6个位移插值点。通过指纹库比对,能够准确识别桩基钢护筒减薄区域的位置与轴向长度。     

Heavy metal resistance and genotypic analysis of metal resistance genes in gram-positive and gram-negative bacteria present in Ni-rich serpentine soil and in the rhizosphere of Alyssum murale

Forty-six bacterial cultures, including one culture collection strain, thirty from the rhizosphere of Alyssum murale and fifteen from Ni-rich soil, were tested for their ability to tolerate arsenate, cadmium, chromium, zinc, mercury, lead, cobalt, copper, and nickel in their growth medium. The resistance patterns, expressed as minimum inhibitory concentrations, for all cultures to the nine different metal ions were surveyed by using the agar dilution method. A large number of the cultures were resistant to Ni (100%), Pb (100%), Zn (100%), Cu (98%), and Co (93%). However, 82, 71, 58 and 47% were sensitive to As, Hg, Cd and Cr(VI), respectively. All cultures had multiple metal-resistant, with heptametal resistance as the major pattern (28.8%). Five of the cultures (about of 11.2% of the total), specifically Arthrobacter rhombi AY509239, Clavibacter xyli AY509235, Microbacterium arabinogalactanolyticum AY509226, Rhizobium mongolense AY509209 and Variovorax paradoxus AY512828 were tolerant to nine different metals. The polymerase chain reaction in combination with DNA sequence analysis was used to investigate the genetic mechanism responsible for the metal resistance in some of these gram-positive and gram-negative bacteria that were, highly resistant to Hg, Zn, Cr and Ni. The czc, chr, ncc and mer genes that are responsible for resistance to Zn, Cr, Ni and Hg, respectively, were shown to be present in these bacteria by using PCR. In the case of, M. arabinogalactanolyticum AY509226 these genes were shown to have high homology to the czcD, chrB, nccA, and mer genes of Ralstonia metallidurans CH34. Therefore, Hg, Zn, Cr and Ni resistance genes are widely distributed in both gram-positive and gram-negative isolates obtained from A. murale rhizosphere and Ni-rich soils.