生物质炭对溶液中Cd~(2+)的吸附

以玉米秸秆、稻壳在350~500℃制成的生物质炭作为吸附剂,研究其对溶液中Cd2+的吸附特性。通过模拟实验,考察了初始p H、生物质炭用量、吸附时间和Cd2+的起始浓度对吸附的影响。结果表明,2种生物质炭对Cd2+的吸附反应适应p H范围较宽(4.0~7.0);玉米秸秆炭和稻壳炭对Cd2+的吸附速度较快,分别在10和20 min时达到吸附平衡;玉米秸秆炭对溶液中Cd2+的吸附遵循Langmuir等温线模型,而稻壳炭对Cd2+的吸附遵循Freundlich等温线模型。在实验设定的条件下,玉米秸秆炭对溶液中Cd2+的吸附能力强于稻壳炭。     

Differential toxicity of arsenic on renal oxidative damage and urinary metabolic profiles in normal and diabetic mice

Diabetes is a common metabolic disease, which might influence susceptibility of the kidney to arsenic toxicity. However, relative report is limited. In this study, we compared the influence of inorganic arsenic (iAs) on renal oxidative damage and urinary metabolic profiles of normal and diabetic mice. Results showed that iAs exposure increased renal lipid peroxidation in diabetic mice and oxidative DNA damage in normal mice, meaning different effects of iAs exposure on normal and diabetic individuals. Nuclear magnetic resonance (NMR)-based metabolome analyses found that diabetes significantly changed urinary metabolic profiles of mice. Oxidative stress-related metabolites, such as arginine, glutamine, methionine, and β-hydroxybutyrate, were found to be changed in diabetic mice. The iAs exposure altered amino acid metabolism, lipid metabolism, carbohydrate metabolism, and energy metabolism in normal and diabetic mice, but had higher influence on metabolic profiles of diabetic mice than normal mice, especially for oxidative stress-related metabolites and metabolisms. Above results indicate that diabetes increased susceptibility to iAs exposure. This study provides basic information on differential toxicity of iAs on renal toxicity and urinary metabolic profiles in normal and diabetic mice and suggests that diabetic individuals should be considered as susceptible population in toxicity assessment of arsenic.     

鄱阳湖出流水质2004~2014年变化及其对水位变化的响应:对水质监测频率的启示

通过对鄱阳湖湖口2004~2014年以周为单位的水质指标,包括溶解氧（DO）,氨氮（NH₄⁺-N）和高锰酸盐指数（COD_Mn）的变化特征及其与水位响应关系进行分析,并对合理的监测频率进行了探讨。结果表明：（1）就DO,NH₄⁺-N和COD_Mn而言,鄱阳湖出湖水质在2004~2014年没有显著恶化的趋势,然而在年内呈现明显的周期性变化,其浓度与湖泊水位波动有较显著的负相关性（p<0.01）,相关系数分别达到-0.63,-0.67和-0.36;（2）考虑水质指标在湖相状态与河相状态存在显著的差异（p<0.01）,概率密度分布曲线进一步表明,在鄱阳湖呈湖相时,湖口NH₄⁺-N浓度小于0.25 mg/L的概率为93%,而在河相时仅为32.8%。DO与COD_Mn浓度在河湖相的特征与NH₄⁺-N相似。因此,在湖相状态下,鄱阳湖出流水质良好的概率更大,而高水位下的稀释作用可能是影响湖泊年内变化的主要控制因素;（3）时间序列分析表明DO,NH₄⁺-N和COD_Mn存在明显的自相关性,1~2月一次的监测频率基本能够准确的描述NH₄⁺-N和DO的动态变化特征,而COD_Mn仍需要1~2周一次的监测,从而避免过多的损失动态信息。能够为将来更深入的研究湖泊水情与水质定量关系提供基础和思路,从而为湖泊水环境管理和调控提供对策和建议。     

基于物种敏感性分布法的毒死蜱对稻田生态系统生态风险评价

生物敏感性分布法(Species Sensitivity Distributions,SSD)是一种基于单物种测试和概率统计学的、较高级的外推风险评估方法。该方法在国内外均被广泛应用于各种污染物风险评价中。本文选取了采用logistic和normal这2种SSD分布模型,分析了国内外毒死蜱对3组水生生物组合的毒性数据;并且获得各自SSD的HCx值。3组毒性数据分别为:浙江稻田水生生物组,长三角地区水生生物组和美国水生生物组。浙江稻田水生物SSD分布的HC5为:0.32μg·L~(-1)(logistic模型)和0.35μg·L~(-1)(normal模型);HC10为1.50μg·L~(-1)(logistic模型)和1.26μg·L~(-1)(normal模型);HC20为8.13μg·L~(-1)(logistic模型)和5.96μg·L~(-1)(normal模型);HC50为145.44μg·L~(-1)(logistic模型)和115.74μg·L~(-1)(normal模型)。据此判断水稻种植季节,稻田水域毒死蜱对食蚊鱼、鳑鲏、泽蛙蝌蚪、轮虫、常见腹足类和双壳类软体动物以及绝大多数藻类等的风险较小。利用冗余分析研究了生物物种数量、物种组成结构和拟合模型对HCx影响。结果表明:物种组成结构对HCx有较为明显的影响。具体表现为对毒死蜱较为敏感物种数量与HCx存在明显的负相关性;对毒死蜱不敏感的物种则与HCx呈现正相关性。     

Enhancing the Ability of a Soil Moisture‐based Index for Agricultural Drought Monitoring by Incorporating Root Distribution

Agricultural drought differs from meteorological, hydrological, and socioeconomic drought, being closely related to soil water availability in the root zone, specifically for crop and crop growth stage. In previous studies, several soil moisture indices (e.g., the soil moisture index, soil water deficit index) based on soil water availability have been developed for agricultural drought monitoring. However, when developing these indices, it was generally assumed that soil water availability to crops was equal throughout the root zone, and the effects of root distribution and crop growth stage on soil water uptake were ignored. This article aims to incorporate root distribution into a soil moisture‐based index and to evaluate the performance of the improved soil moisture index for agricultural drought monitoring. The Huang‐Huai‐Hai Plain of China was used as the study area. Overall, soil moisture indices were significantly correlated with the crop moisture index (CMI), and the improved root‐weighted soil moisture index (RSMI) was more closely related to the CMI than averaged soil moisture indices. The RSMI correctly identified most of the observed drought events and performed well in the detection of drought levels. Furthermore, the RSMI had a better performance than averaged soil moisture indices when compared to crop yield. In conclusion, soil moisture indices could improve agricultural drought monitoring by incorporating root distribution.     

Morphological and chemical composition characteristics of summertime atmospheric particles collected at Tokchok Island,Korea

Determination of the chemical compositions of atmospheric single particles in the Yellow Sea region is critical for evaluating the environmental impact caused by air pollutants emitted from mainland China and the Korean peninsula. After ambient aerosol particles were collected by the Dekati PM10 cascade impactor on July 17–23, 2007 at Tokchok Island (approximately 50 km west of the Korean coast nearby Seoul), Korea, overall 2000 particles (on stage 2 and 3 with cut-off diameters of 2.5–10 μm and 1.0–2.5 μm, respectively) in 10 samples were determined by using low-Z particle electron probe X-ray microanalysis. X-ray spectral and secondary electron image (SEI) data showed that soil-derived and sea-salt particles which had reacted or were mixed with SO₂ and NO_x (or their acidic products) outnumbered the primary and “genuine” ones (59.2% vs. 19.2% in the stage 2 fraction and 41.3% vs. 9.9% in the stage 3 fraction). Moreover, particles containing nitrate in the secondary soil-derived species greatly outnumbered those containing sulfate. Organic particles, mainly consisting of marine biogenic species, were more abundant in the stage 2 fraction than in the stage 3 fraction (11.6% vs. 5.1%). Their relative abundance was greater than the sum of carbon-rich, K-containing, Fe-containing, and fly ash particles, which exhibited low frequencies in all the samples. In addition, many droplets rich in C, N, O, and S were observed. They tended to be small, exhibiting a dark round shape on SEI, and generally included 8–20 at.% C, 0–12 at.% N, 60–80 at.% O, and 4–10 at.% S (sometimes with <3 at.% Mg and Na). They were attributed to be a mixture of carbonaceous matter, H₂SO₄, and NH₄HSO₄/(NH₄)₂SO₄, mostly from the reaction of atmospheric SO₂ with NH₃ under high relative humidity. The analysis of the relationship between the aerosol particle compositions and 72-h backward air-mass trajectories suggests that ambient aerosols at Tokchok Island are strongly affected not only by seawater from the Yellow Sea but also by anthropogenic pollutants emitted from China and the Seoul–Incheon metropolis, resulting in the dominance of complex secondary aerosol particles.     

一种新型光催化剂用于降解腈纶废水研究

将1,10菲啰啉和铁Fe2+溶液配成络合物负载到D113树脂上作为可见光催化剂,利用该催化剂对腈纶废水进行了降解研究,考察了该负载型铁氮配合物催化剂处理腈纶废水的影响因素。由实验结果可知,该催化剂处理腈纶废水最佳条件为：过氧化氢浓度为400 mg/L,催化剂用量为5 g/L,最佳pH值范围为4～9,COD降解率可达68.7%,实现了在温和的反应条件下,即常温、常压、宽pH范围进行反应,充分利用了可见光来处理难降解有机物。     

西安南郊采暖期大气颗粒物PM2.5的污染特征分析

为研究西安市南郊地区采暖期大气颗粒物PM2.5的污染浓度及水溶性成分,使用颗粒物采样器于2009年1月6日～2009年2月15日进行PM2.5采样.将24 h分为8个阶段,每天3 h定时采样.结果表明,西安市南郊地区采暖期PM2.5明显污染,24 h中PM2.5污染状况最严重的时段为21:00～23:59;PM2.5中NH+4、NO-3和SO2-4是其最主要的水溶性组分,在PM2.5中的平均质量混合比分别为10.225%、13.698%和15.650%,三者在PM2.5中质量混合比最高的时段分别为06:00～08:59、03:00～05:59和18:00～20:59.     

基于改进生态足迹模型的成都市可持续发展状况分析

在介绍生态足迹的概念和计算方法及目前的研究成果的基础上,分析生态足迹模型存在的缺陷和不足,提出了生态足迹改进模型,对成都市2003年至2007年的生态足迹进行了计算,并对成都市的可持续发展状况进行分析.结果表明:成都市人均生态足迹从2003年的1.1221hm2增长到2007年的1.1914hm2,人均生态承载力从2003年的0.2902hm2减少到2007年的0.2580hm2.根据在改进模型下的指标计算结果,近5年来成都市经济有了一定发展,但仍处于相对落后的阶段,而且生态压力大,生态与经济的协调性差,生态建设和经济发展的任务还很艰巨.