Application of polyacrylamide to reduce phosphorus losses from a Chinese purple soil: A laboratory and field investigation

Use of anionic polyacrylamide (PAM) to control phosphorus (P) losses from a Chinese purple soil was studied in both a laboratory soil column experiment and a field plot experiment on a steep slope (27%). Treatments in the column study were a control, and PAM mixed uniformly into the soil at rates of 0.02, 0.05, 0.08, 0.10, and 0.20%. We found that PAM had an important inhibitory effect on vertical P transport in the soil columns, with the 0.20% PAM treatment having the greatest significant reduction in leachate soluble P concentrations and losses resulting from nine leaching periods. Field experiments were conducted on 5 m wide by 21 m long natural rainfall plots, that allowed collection of both surface runoff and subsurface drainage water. Wheat was planted and grown on all plots with typical fertilizer applied. Treatments included a control, dry PAM at 3.9 kg ha^?1, dry PAM at 3.9 kg ha^?1 applied together with lime (CaCO₃ at 4.9 t ha^?1), and dry PAM at 3.9 kg ha^?1 applied together with gypsum (CaSO₄·2H₂O at 4 t ha^?1). Results from the field plot experiment in which 5 rainfall events resulted in measurable runoff and leachate showed that all PAM treatments significantly reduced runoff volume and total P losses in surface runoff compared to the control. The PAM treatments also all significantly reduced water volume leached to the tile drain. However, total P losses in the leachate water were not significantly different due to the treatments, perhaps due to the low PAM soil surface application rate and/or high experimental variability. The PAM alone treatment resulted in the greatest wheat growth as indicated by the plant growth indexes of wheat plant height, leaf length, leaf width, grain number per head, and dried grain mass. Growth indexes of the PAM with Calcium treatments were significantly lesser. These results indicate that the selection and use of soil amendments need to be carefully determined based upon the most important management goal at a particular site (runoff/nutrient loss control, enhanced plant growth, or a combination).     

膨胀珍珠岩负载Eu3+-TiO2催化剂的制备及其催化性能

以膨胀珍珠岩(EP)为载体,采用溶胶-凝胶法制备了Eu3+-TiO2/EP催化剂.通过XRD和SEM等方法对催化剂进行了表征,以对硝基苯酚溶液为目标物,进行了催化剂活性的研究.实验结果表明,Eu3+的掺杂有效抑制了TiO2晶粒的增长,减小了晶粒尺寸,提高了晶粒的分散性,明显提高了催化剂的活性.在Eu3+掺杂量(Eu3+与Ti的摩尔比)1.0％、焙烧温度500℃、催化剂加入量6 g/L的最佳条件下,对硝基苯酚去除率达87％.     

元谋干热河谷植物功能性状组合的海拔梯度响应

植物功能性状能够显示对环境变化的响应,不同的适应对策呈现出不同的功能性状组合。干热河谷地区水分是最主要的限制性环境因子,之前的大部分研究都是集中关注于干热河谷局部地段,对于从垂直海拔上来研究不同植物在环境梯度下的变化的研究较少。干热河谷地区由于梵风效应,水分胁迫沿海拔梯度发生变化,一般表现为随海拔高度升高,气温降低,湿度和降水量增加,而蒸发量减小,辐射增强。以云南元谋干热河谷4个海拔梯度（1491.33、1730.20、1850.00、1925.57 m）中的植物为研究对象,选取叶片干物质含量（LDMC）、叶面积（LA）、比叶面积（SLA）、叶片厚度（LT）和叶密度（LD）5个功能性状,研究它们的相互关系,比较了海拔间的差异。结果表明：1）5个功能性状在不同海拔间均呈现出一定差异,变异系数由高到低为LD>LA>SLA>LT>LDMC（分别是101%、64%、56%、41%和19%）;方差分析结果也表明,5个功能性状在不同海拔之间差异显著（F=56.218,P<0.01;F=7.829,P<0.01;F=11.21,P<0.01;F=7.429,P<0.01;F=19.213,P<0.01）,尤其是在最低（1491.33 mm）和最高（1927.57 mm）海拔之间,各性状均具有极显著的差异;2）性状之间存在组合关系, LD与其他性状间相关性最为明显,除LDMC以外,LD与LA、SLA、LT均呈现出极显著负相关关系;LDMC与LA和LT呈极显著负相关;SLA与LA和LT呈正相关,而与LDMC显著负相关;LT与SLA显著正相关,与LA之间相关性不显著;3）在不同的海拔梯度之间,性状组合存在非同步变化现象。研究显示,元谋干热河谷地区,植物对水分环境的海拔梯度变化产生功能性状组合的响应,低海拔和高海拔物种对所处环境的适应策略不同,使得植物在海拔梯度上出现叶片功能性状组合的分化和差异。     

页岩气开发压裂返排液环境监管及对策建议

水力压裂技术是目前页岩气开发广泛采用的储层改造技术,但该技术的应用产生大量的返排液,返排液如何处置和监管引起了人们的广泛关注。本文收集了国内外压裂液的成分、返排液的水量和水质等资料,从深井灌注、市政污水处理厂处理后外排、现场处理后回用、现场处理后外排四种处理方式上,分析我国返排液环境监管存在的问题,针对实际问题提出对策建议,包括对化学品进行申报登记、制订污水排放的行业标准、对页岩气开发项目进行分段验收、鼓励研发污水处理新技术等。     

油类废水采样器的优化研究

一般说来,在水体中油的分布是很不均匀的,除少部分乳化状油较为均匀地存在于水体,大部分多分散浮于水面,若用普通采水器完全不能满足要求.因此,油类的环境监测采样要求必须单独使用采样器或专用采样器,并应定容或定面积采样,且不得在实验室再行分样.该研究根据永州市废水污染源的特点,设计制作出水中不均匀分布污染物油类的专用采样器,研究结果表明,其精密度和准确度方面明显优于普通采水器.     

基于模糊综合评价法的污水处理行业绩效评价研究

为弥补污水处理行业绩效评价方法的空白,从污水处理行业发展模型出发,构建了污水处理行业绩效评价指标体系,包含行业发展外部环境和行业现状与效益两个指标体系,采用层次分析法确定了指标权重,采用模糊综合评价法对2009年-2011年国内污水处理行业开展了绩效评价研究.评价结果表明,2009年-2011年期间,污水处理行业绩效越来越好,但仍有发展的空间,为进一步提高行业绩效,未来应在加大污染治理投资、做好污水处理设施与城镇建设的同步发展、加大技术研发投入等方面采用强有力的措施.     

北京平原区夏垫断裂的多源遥感影像特征

1679年9月2日三河—平谷8.0级地震在地表形成总体走向N40°~45°E,倾角60°~70°,长达10 km的破裂带。该文采用Landsat-8、SPOT-5、SAR、GDEM、Google Earth多源遥感影像研究夏垫断裂的遥感影像特征。利用ERDAS软件,对Landsat-8影像按7∶4∶2依次为R、G、B分量作彩色合成增强处理,突出影像的线性构造特征;对Landsat-8和SPOT-5影像、Landsat-8和SAR影像分别进行融合处理,丰富影像的光谱信息;对GDEM与SPOT影像进行三维叠加,突出影像的三维特征;对SAR影像进行斑点压缩、方向滤波处理,突出影像平行断裂方向的线性特征。文中分析、对比了Google Earth和SPOT-5影像上地震陡坎的特征,陡坎在SPOT-5影像上表现较明显,但在影像上表现不出较低陡坎,同时,在两种影像上容易将绿色植被、狭窄道路或其它地物误认为陡坎;SAR滤波后的影像表现出暗色的线性条带;Landsat-8和SAR融合后的影像表现出较宽的异常条带,该条带指示断裂带所在位置。     

Unexpected phenotypes of malformations induced in Xenopus tropicalis embryos by combined exposure to triphenyltin and 9-cis-retinoic acid

Xenopus tropicalis embryos were exposed for 48 hr to the mixtures of 5 g Sn/L triphenyltin(TPT), which is a well-known endocrine disruptor, and 0.25–5 g/L 9-cis retinoic acid(9c-RA), which is the natural ligand of retinoid X receptor. The phenotypes induced by combined exposure were more variable than those resulting from single exposure to either TPT or 9c-RA. The prominent phenotypes included underdeveloped head structures, abnormal eyes, narrow fins, enlarged proctodaeum, etc. Especially, combined exposure induced unexpected notochord malformations, which ranged from small swellings of the surface of the tails to the extension and extrusion of notochord out of the posterior tails. Compared with the 5 g Sn/L TPT-treated group, the index of fin deficiency was not affected, and the index of axis deficiency was significantly increased with increasing RA concentrations in the mixtures. Our results suggest that combined exposure to TPT and 9c-RA induced not only more variable phenotypes of malformations than exposure to single compound but also some new and unexpected phenotypes.     

Characteristics of secondary inorganic aerosol and sulfate species in size-fractionated aerosol particles in Shanghai

Sulfate, nitrate and ammonium(SNA) are the dominant species in secondary inorganic aerosol, and are considered an important factor in regional haze formation. Size-fractionated aerosol particles for a whole year were collected to study the size distribution of SNA as well as their chemical species in Shanghai. SNA mainly accumulated in fine particles and the highest average ratio of SNA to particulate matter(PM) was observed to be 47% in the fine size fraction(0.49–0.95 μm). Higher sulfur oxidation ratio and nitrogen oxidation ratio values were observed in PM of fine size less than 0.95 μm. Ion balance calculations indicated that more secondary sulfate and nitrate would be generated in PM of fine size(0.49–0.95 μm). Sulfur K-edge X-ray absorption near-edge structure(XANES) spectra of typical samples were analyzed. Results revealed that sulfur mainly existed as sulfate with a proportion(atomic basis) more than 73% in all size of PM and even higher at 90% in fine particles. Sulfate mainly existed as(NH4)2SO4 and gypsum in PM of Shanghai. Compared to non-haze days, a dramatic increase of(NH4)2SO4 content was found in fine particles on haze days only, which suggested the promoting impact of(NH4)2SO4 on haze formation. According to the result of air mass backward trajectory analysis, more(NH4)2SO4 would be generated during the periods of air mass stagnation. Based on XANES, analysis of sulfate species in size-fractionated aerosol particles can be an effective way to evaluate the impact of sulfate aerosols on regional haze formation.     

强化我国引进环境保护技术宏观调控的探讨

１０年来,我国引进环境保护技术近万项,总金额近千亿元。如何充分发挥引进环境保护技术的作用,推动我国环境科学技术的进步,必须对我国引进环境保护技术进行宏观调控,本文对建立和完善我国引进环境保护技术运行机制等进行了探讨。