低进水浓度CASS工艺沿程污染物去除特征及微生物群落变化

南方部分城镇污水浓度偏低,而循环式活性污泥法(CASS)能较好地处理低浓度污水,处理性能与微生物群落特征密切相关,但鲜有研究涉及其沿程微生物群落结构变化。本研究选取广东省某CASS城镇污水厂作为典型案例,分析其沿程污染物去除特征和微生物变化,从微生物学角度探讨污染物的去除机理。结果表明：低进水浓度CASS生化池沿程耗氧有机物(以COD计)、TN、NO₃⁻-N、TP主要在污泥选择区被吸附降解,进水1 h COD和TP值降至最低,NH₄⁺-N主要在主反应区被氧化降解,生化池可去除污水中56.42%的耗氧有机物(以COD计)、41.71%的TN、77.78%的NH₄⁺-N、99.59%的TP。生化池主要优势菌门有变形菌门、拟杆菌门、绿弯菌门和浮霉菌门,变形菌门是影响微生物多样性变化的关键菌门。属水平上,进水1 h选择区Zoogloea、Aeromonas和Thauera丰度较高,主反应区Nitrospira丰度较高;进水结束选择区Nitrospira丰度较高,主反应区Terrimonas和Lactobacillus丰度较高;沉淀1 h选择区Thauera丰度提高,主反应区Nitrosomonas丰度较高,主要发生氨氧化;闲置结束选择区脱氮菌类型多丰度高,主反应区Sulfuritalea、Haliangium、Zoogloea丰度较高。沿程功能性微生物丰度变化与污染物浓度变化相对应。NO₃⁻-N对微生物群落结构的塑造影响最显著(解释度为38.92%)。氮代谢途径表明沿程主反应区均发生全程硝化反硝化,选择区均发生短程硝化和全程反硝化,除进水1 h外,其余阶段选择区的反硝化功能基因丰度均比主反应区高。     

环境污染物的分子毒理机制研究进展

以分子生物学技术为基础研究污染物的毒理机制．从分子水平揭示了污染物毒作用的本质。综述了国内外分子毒理机制的研究进展。详细阐述了毒理芯片、单细胞凝胶电泳等分子生物学技术应用与毒理学研究中的特点、应用前景以及存在的问题。提出了分子毒理机制今后的研究方向。     

江苏海岸湿地水质污染特征与海陆一体化调控

2000年江苏海岸湿地人海河流河口淡水监测断面有30％的水质处于劣Ⅴ类,满足Ⅲ类水质的仅占10％;近岸海域海水监测断面有50％的水质处于Ⅳ标准。人类扰动的频率与强度的日益加大是水质污染的主要原因,而河流携带大量污染物是水质污染的主要途径。江苏海岸湿地水质污染防治的关键在于流域海陆水环境系统的一体化调控,侧重点是调控技术路线和水质污染控制层次的设计。环境管理控制区划的方案是：横向上由陆向海划分为上游流域、近岸陆域、海岸湿地和离岸海域4个环境控制带;纵向上自北向南以水系汇流特征、行政区划特征、海域特点划分为Ⅳ类环境功能区及若干亚区。     

Air pollutant concentrations near three Texas roadways,Part I: Ultrafine particles

Vehicular emitted air pollutant concentrations were studied near three types of roadways in Austin, Texas: (1) State Highway 71 (SH-71), a heavily traveled arterial highway dominated by passenger vehicles; (2) Interstate 35 (I-35), a limited access highway north of Austin in Georgetown; and (3) Farm to Market Road 973 (FM-973), a heavily traveled surface roadway dominated by truck traffic. Air pollutants examined include carbon monoxide (CO), oxides of nitrogen (NO_x), and carbonyl species in the gas-phase. In the particle phase, ultrafine particle (UFP) concentrations (diameter < 100 nm), fine particulate matter (PM_2.5, diameter < 2.5 μm) mass and carbon content and several particle-bound organics were examined. All roadways had an upwind stationary sampling location, one or two fixed downwind sample locations and a mobile monitoring platform that characterized pollutant concentrations fall-off with increased distance from the roadways. Data reported in this paper focus on UFP while other pollutants and near-roadway chemical processes are examined in a companion paper. Traffic volume, especially heavy-duty traffic, wind speed, and proximity to the road were found to be the most important factors determining UFP concentrations near the roadways. Since wind directions were not consistent during the sampling periods, distances along wind trajectories from the roadway to the sampling points were used to study the decay characteristics of UFPs. Under perpendicular wind conditions, for all studied roadway types, particle number concentrations increased dramatically moving from the upwind side to the downwind side. The elevated particle number concentrations decay exponentially with increasing distances from the roadway with sharp concentration gradients observed within 100–150 m, similar to previously reported studies. A single exponential decay curve was found to fit the data collected from all three roadways very well under perpendicular wind conditions. No consistent pattern was observed for UFPs under parallel wind conditions. However, regardless of wind conditions, particle concentrations returned to background levels within a few hundred meters of the roadway. Within measured UFP size ranges, smaller particles (6–25 nm) decayed faster than larger ones (100–300 nm). Similar decay rates were observed among UFP number, surface, and volume.     

炼油厂恶臭污染物的防治

论述了炼厂恶臭气体的防治方法，主要从密闭的生产装置、酸性水储罐及污水处理系统几个方面进行了分析并提出了目前为解决恶臭污染采取的方法。     

高速飞机弹射救生时的气流吹袭及其防护

飞行员在高速弹离飞机时,会受到气流的吹袭。如何防护高速弹射时受到的气流吹袭,是各国航空救生业一直致力解决的问题。本文介绍了高速气流吹袭的危害性和对人体的影响,以及可以采取的一些防护措施,供科研人员参考。     

Research and application of method of oxygen isotope of inorganic phosphate in Beijing agricultural soils

Phosphorus (P) in agricultural ecosystems is an essential and limited element for plants and microorganisms. However, environmental problems caused by P accumulation as well as by P loss have become more and more serious. Oxygen isotopes of phosphate can trace the sources, migration, and transformation of P in agricultural soils. In order to use the isotopes of phosphate oxygen, appropriate extraction and purification methods for inorganic phosphate from soils are necessary. Here, we combined two different methods to analyze the oxygen isotopic composition of inorganic phosphate (δ¹⁸O_P) from chemical fertilizers and different fractions (Milli-Q water, 0.5 mol L^?1 NaHCO₃ (pH = 8.5), 0.1 mol L^?1 NaOH and 1 mol L^?1 HCl) of agricultural soils from the Beijing area. The δ¹⁸O_P results of the water extracts and NaHCO₃ extracts in most samples were close to the calculated equilibrium value. These phenomena can be explained by rapid P cycling in soils and the influence of chemical fertilizers. The δ¹⁸O_P value of the water extracts and NaHCO₃ extracts in some soil samples below the equilibrium value may be caused by the hydrolysis of organic P fractions mediated by extracellular enzymes. The δ¹⁸O_P values of the NaOH extracts were above the calculated equilibrium value reflecting the balance state between microbial uptake of phosphate and the release of intracellular phosphate back to the soil. The HCl extracts with the lowest δ¹⁸O_P values and highest phosphate concentrations indicated that the HCl fraction was affected by microbial activity. Hence, these δ¹⁸O_p values likely reflected the oxygen isotopic values of the parent materials. The results suggested that phosphate oxygen isotope analyses could be an effective tool in order to trace phosphate sources, transformation processes, and its utilization by microorganisms in agricultural soils.     

应用地累积指数评价鞍山市夏季PM2.5中元素的污染

2014年夏季在鞍山市的6个站点进行了PM2.5的样品采集,对其载带的15种元素进行了检测。通过地累积指数、相关分析和聚类分析等方法分析了鞍山市夏季PM2.5中15种元素的污染来源。结果表明:Ca、Zn、Pb、Ni和Cd这5种元素的质量分数在各站点之间存在较大的差异;地累积指数结果显示,Cd为极强污染程度,可能的来源是钢铁冶炼和刹车及轮胎磨损,Pb和Zn污染程度在强污染以上,Pb可能的主要人为来源是钢铁冶炼和窖炉煤的燃烧,Zn可能主要来自钢铁冶炼和机动车,Cu、Ni、Cr和Ca中到强污染以下;聚类分析将中度污染及以上元素分为Zn-Cd-Pb,Ni-Cu-Cr和Ca 3类,分别指示钢铁冶炼、机动车尾气及刹车、轮胎磨损,建筑尘;相关性分析显示,Cr与Ni、Cu可能来自同一污染源,Zn、Cd和Pb可能来自同一种源。     

聚合物水凝胶的制备以及吸附废水中铅离子

以2-丙烯酸羟乙酯(HEA)和L-半胱氨酸(L-Cys)为单体,采用辐射共聚法制备了对Pb2+具有高效吸附性能的水凝胶,利用改性剂(乙酰胺基-L-半胱氨酸)对共聚物水凝胶进行了改性,应用SEM、FT-IR、XPS等方法表征了水凝胶的性能,研究了改性后水凝胶在不同pH以及不同温度条件下对Pb2+的吸附效果,探讨了水凝胶吸附Pb2+的吸附机理,并且采用EDTA二钠为脱附剂,探索了水凝胶的重复利用能力。     

聚醚砜小球负载Comamonas sp.(bdq06)生物降解水中的喹啉

以聚醚砜为原料制备了一种具有多孔道的小球载体,负载睾丸酮丛毛单孢菌(bdq06)降解水中喹啉。制备的小球直径约3 mm,表面光滑,存在厚度约20μm的致密层。经过浸蚀去掉致密层后,露出粗糙表面,有助于细菌粘附和生殖。同时出现大量直径约1.5μm的孔道,且由外向内,孔径逐渐增大,细菌可以通过表层孔进入球内生殖。在pH为5、10和温度为40℃的条件下,负载菌的小球对水中喹啉的降解效果优于游离菌。小球具有良好的溶胀性和机械强度,经过多次重复使用后,球形完整而未破裂,细菌在球表面大量生殖形成生物膜,显著提高降解效率,能够在1 h内完全降解100 mg/L喹啉。以聚醚砜为原料制备的小球在废水处理中具有潜在应用前景。