大宝山矿区水体中重金属的行为研究

广东大宝山矿区矿山废水的排放使周边生态环境遭受了严重的破坏。水体中重金属Cu、Zn、Cd和Pb的溶解态浓度分别达到13.82、50.83、0.103和2.91 mg.L-1。Cu、Zn、Cd和Pb的溶解态和悬浮态含量沿河流主干道断面呈相似的空间分布规律,上游都是沿水流方向降低,下游因吸附于悬浮物中的重金属重新释放略有增加。悬浮物中重金属元素的化学形态提取和扫描电镜能谱分析(SEM/EDAX)表明:4种重金属元素都以残渣态为主要存在形态,其次为可还原态,个别断面的Cd可还原态甚至超过了残渣态的含量,说明该水体这4种元素对环境都有一定的潜在威胁性。     

Effects of cerium on growth and physiological mechanism in plants under enhanced ultraviolet-B radiation

Effect of cerium （Ce^3＋） on the growth, photosynthesis and antioxidant enzyme system in rape seedlings （Brassica juncea L.） exposed to two levels of UV-B radiation （T1： 0.15 W/m^2 and T2：0.35 W/m^2） was studied by hydroponics under laboratory conditions. After 5 d of UV-B treatment, the aboveground growth indices were obviously decreased by 13.2%-44. 1%（T1） and 21.4%-49.3% （T2）, compared to CK, and except active absorption area of roots, the belowground indices by 14.1%-35.6%（T1） and 20.3%-42.6% （T2）. For Ce＋UV-B treatments, the aboveground and belowground growth indices were decreased respectively by 4.1%-23.6%, 5.2% -23.3%（Ce＋T1） and 10.8%-28.4%, 7.0%-27.8%（Ce＋T2）, lower than those of UV-B treatments. The decrease of growth indices appeared to be the result of changes of physiological processes. Two levels of UV-B radiation induced the decrease in chlorophyll content, net photosynthesis rate, transpiration rate, stomatal conductance and water use efficiency by 11.2%-25.9%（T1） and 20.9%- 56.9%（T2）, whereas increase in membrane permeability and activities of antioxidant enzymes including superoxide dismutase（SOD）, catalase （CAT） and peroxidase （POD） by 6.9%, 22.8%, 21.5%, 9.5%（T1） and 36.6%, 122.3%, 103.5%, 208.9%（T2）, respectively. The reduction of the photosynthetic parameters in Ce＋UV-B treatments was lessened to 3.2%-13.8%（Ce＋T1） and 4.9%-27.6%（Ce＋T2）, and the increase of membrane permeability and activities of antioxidant enzymes except POD in the same treatments were lessened to 2.4%, 8.4%, 6.6%（Ce＋T1） and 30.1%, 116.7%, 75.4%（Ce＋T2）. These results indicate that the regulative effect of Ce on photosynthesis and antioxidant enzymatic function is the ecophysiological basis of alleviating the suppression of UV-B radiation on growth of seedlings. Furthermore, the protective effect of Ce on seedlings exposed to TI level of UV-B radiation is superior to T2 level.     

国外道路声屏障结构形式的研究进展

介绍了不同结构形式新型屏障的降噪基本原理、性能特征及发展动态，并对它们降噪性能进行了比较。     

瓦里关山大气CO2及其δ13C本底变化

利用 1991— 2 0 0 1年期间实测资料 ,分析了瓦里关全球基准站大气CO2 及其δ13 C本底特征 ,并探讨了与源汇过程的关系 .结果表明 ,瓦里关大气CO2 及其δ13 C本底变化主要反映了北半球中高纬度大陆自然生态系统源汇的周期性季节特征 ,而海洋的作用相对较弱 ;大气CO2 及其δ13 C本底浓度范围与所处纬度带平均状况基本吻合 ,年平均值以及年际间涨落与全球水平的一致性反映出化石燃料燃烧等人为排放对大气圈的全球性影响 ;瓦里关站提供的主要温室气体本底观测资料 ,既能体现亚洲内陆地域特点又具有全球代表性 ,配合以其它相关资料 ,还可进一步揭示中国内陆高原大气CO2 及其δ13 C本底特征的成因 .     

生物电耦合对活性炭-超滤工艺处理地表微污染水的影响机理研究

利用生物电化学系统处理地表水时，弱电压不但会刺激电活性菌的呼吸作用，而且会引起氧化胁迫导致胞外聚合物（Extracellular Polymeric Substance，EPS）过量分泌.为确认在地表水处理中弱电压对膜污染和净水效率的影响，本研究设置了外加1.0 V直流电压（记为"BES系统"）和无外加电压（记为"CK系统"）的两组平行对照生物活性炭-超滤系统.经过50 d的运行，BES系统（36.1 kPa）相比CK系统（19.1 kPa）跨膜压差（Trans Membrane Pressure，TMP）增加更为显著，膜污染更严重.电路电流、电极电势和循环伏安（Cyclic Voltammetry，CV）曲线显示，随着装置运行，两系统生物膜逐渐稳定，并且产生具有氧化还原活性的EPS导致阳极电容增加.相比之下，BES系统产生了更多EPS，具有更高的阳极电容.水质指标显示，BES系统中比紫外吸光度（Specific Ultraviolet Absorbance，SUVA）、NH₄⁺-N和PO₄^3--P的去除增强但总有机碳（Total Organic Carbon，TOC）去除减弱；三维荧光光谱（Excitation-Emission-Matrix，EEM）和尺寸排阻色谱（Size Exclusion Chromatography，SEC）分析结果表明，BES系统膜池中产生了更多的生物聚合物，但腐殖质类有机物明显减少.活性炭表面EPS含量和腺嘌呤核苷三磷酸（Adenosine Triphosphate，ATP）含量的测试结果证实，弱电压刺激了生物膜的生长，同时增加了氧化还原活性EPS的含量.对膜表面累积多糖、蛋白质含量的测试分析进一步揭示了多糖类大分子生物聚合物在膜表面的累积是导致严重膜污染的直接原因.研究可为生物电化学系统在微污染水处理的研究和应用提供新的见解.     

乙草胺、铜污染共存对土壤甲胺磷蚯蚓降解过程的影响研究

为揭示利用蚯蚓活动强化甲胺磷降解的可行性,采用了微宇宙培养方法,通过有蚯蚓和无蚯蚓的对比实验,考察了乙草胺和铜分别与甲胺磷共存条件下污染黑土中甲胺磷降解过程的动态变化.结果表明,无论是否加入蚯蚓,甲胺磷单一污染的土壤中甲胺磷的降解符合一级反应动力学规律;蚯蚓活动能促进甲胺磷降解过程的进行.土壤中乙草胺或铜与甲胺磷共存时,均明显地干扰了甲胺磷降解过程随时间的动态变化;根据化学结构分析,推测两者对甲胺磷降解规律的影响机制可能类似.铜与甲胺磷复合污染的土壤中甲胺磷含量明显高于乙草胺与甲胺磷复合组,说明铜较乙草胺对土壤甲胺磷降解过程的延缓作用更强.     

纳米TiO2光催化脱色效果的影响研究

采用偶联剂法制备负载型纳米TiO2光催化剂，对染料废水进行脱色试验研究。结果发现，将废水pH值控制在10～11，通过曝气、添加H2O2、Fe^3 等措施能有效提高废水脱色效果，脱色率在95％以上。     

Aquafluor藻细胞活体分析法在三峡库区次级河流回水区Chla测定中的校准及应用

从三峡库区次级河流大宁河、小江、汤溪河及梅溪河139m回水区中段采集水样,经实验室培养后,用丙酮萃取分光光度法和Aquafluor藻细胞活体分析法测定Chla浓度.通过对Chla萃取值(y)和活体值(x)进行回归分析,得到其回归方程为y=4.15x 2.48,t检验显示回归方程具有线性.在库区次级河流139m回水区富营养化监测中,Chla模拟值与萃取值基本吻合,相对误差＜±7%,故可以采用Chla模拟值对水体富营养化程度进行评价.     

Toxicity assessing for chlorpyrifos-contaminated soil with three different earthworm test methods

Earthworm toxicity tests are useful tools for terrestrial risk assessment but require a hierarchy of test designs that differ in effect levels (behavior, sublethal, lethal). In this study, the toxicity of chlorpyrifos contaminated soil on earthworms was assessed. In addition to the acute and chronic tests, an avoidance response test was applied. Earthworms were exposed to sublethal and lethal concentration of chlorpyrifos, and evaluated for acute toxicity, growth, fecundity and avoidance response after a certain exposure period. The test methods covered all important ecological relevant endpoints (acute, chronic, behavioral). Concentration of 78.91 mg/kg, chlorpyrifos caused significant toxic effects in all test methods, but at lower test concentrations, only significant chronic toxic effects could be observed. In the present study, chlorpyrifos had adverse effect on growth and fecundity in earthworm exposed to 5 mg/kg chlorpyrifos after eight weeks. The avoidance response test, however, showed significant repellent effects concentration of 40 mg/kg chlorpyrifos. For chlorpyrifos, concentration affecting avoidance response was far greater than growth and fecundity, it seemed likely that earthworms were not able to escape from pesticide-contaminated soil into the clean soil in field and hence were exposed continuously to elevated concentrations of pesticides.     

中空纤维膜脱气工艺处理给水的试验研究

研究了中空纤维膜脱气工艺，测定了在不同的液相流速、流量下，膜的氧传质系数、脱氧脱二氧化碳的效率变化以及膜管的放置方式对脱气效率的影响。