添加炭基材料对蔬菜废物好氧堆肥进程和腐熟度的影响

以蔬菜废弃物辣椒秸秆和树叶为堆肥原料(CK),采用密闭式好氧堆肥工艺,研究了添加5%木本泥炭(T1)、5%活性炭(T2)和10%木本泥炭(T3)等炭基材料对堆肥pH、EC、CO2累积量、物料损失率、T值、C/N和发芽率指数的影响。结果显示,T2处理的pH在60 d后维持在8~9之间;EC值随着堆肥进行呈现先下降后升高再下降的趋势,最终CK、T1、T2和T3处理的EC值(mS/cm)分别降低了1.02、0.76、0.33和0.48;T2和T3处理的CO2累积量一直高于其他处理;所有处理的物料损失率均在20%以上;4个处理堆肥产品的T值分别为0.56、0.65、0.68和0.69;堆肥产品的发芽率指数分别为63.2%、69.3%、93.5%和86.1%。T值和发芽率指数显示T2和T3处理达到了腐熟阶段。结果表明,在蔬菜堆肥处理中添加炭基材料可改善堆肥产品的理化性质,加速堆肥物料的分解,有效地缩短堆肥周期和提高堆肥产品的腐熟度。     

江苏省8个沿海造林树种的耐盐性评价研究

以江苏省盐城市大丰区沿海地区为研究区域,选择中山杉（Taxodium 'Zhongshanshan'）、白榆（Ulmus pumila）、落羽杉（Taxodium distichum）、榔榆（Ulmus parvifolia）、乌桕（Triadica sebifera）、青皮柳（Salix ohsidare）、构树（Broussonetia papyrifera）和苦楝（Melia azedarach）8个造林树种,研究不同树种造林地土壤含盐量及其与树木成活率、胸径和树高生长量的关系,并对8个树种的耐盐性进行隶属函数法综合评价,以进一步研究江苏沿海地区典型树种的耐盐性。结果表明,48个调查样地土壤含盐量为0.4~11.9 mg/g;不同样地之间的土壤含盐量差异较大;土壤含盐量较高的样地具有典型的盐分表聚现象;8个树种的成活率、胸径和树高年生长量与土壤含盐量均呈负相关。8个造林树种的耐盐性评价结果显示,其耐盐能力表现为白榆>苦楝>落羽杉>乌桕>榔榆>中山杉>青皮柳>构树。其中,白榆和苦楝可耐受6 mg/g的土壤含盐量;落羽杉、乌桕、榔榆和中山杉可耐受4 mg/g的土壤含盐量;青皮柳和构树只能耐受3 mg/g的土壤含盐量。白榆和苦楝可在含盐量较高的沿海地区造林,落羽杉、乌桕、榔榆和中山杉可在含盐量中等的沿海地区造林,青皮柳和构树只能在含盐量较低的沿海地区造林。

     

实现我国煤矸石“无废”化目标的路径研究

为解决煤矸石大量堆积造成的环境污染问题,基于“无废城市”建设理念和经验提出了煤矸石“无废”化目标。在分析我国煤矸石产生、分布及理化性质的基础上,从煤炭清洁高效利用和减污降碳2个方面论述实现煤矸石“无废”化的必要性,阐述实现我国煤矸石“无废”化的政策基础、技术现状和存在的问题。建议我国在建设绿色生态煤矿、提高煤矸石综合利用水平、研发煤矸石综合利用技术、制定煤矸石综合利用产品标准4个方面开展工作;加快实现以井下采选充一体化、矿井充填、采坑以及塌陷区回填生态修复为核心的煤矸石综合利用技术工业化应用;构建“发电—有用（价）组分回收或利用—高性能建材或农业应用或矿井充填”的资源化利用产业链,实现煤矸石中多组分梯级分质高值化利用,以保障我国煤矸石“无废”化目标顺利实现。

     

Influence of urban morphological parameters on the distribution and diffusion of air pollutants: A case study in China

Air pollution has a serious fallout on human health, and the influences of the different urban morphological characteristics on air pollutants cannot be ignored. In this study, the relationship between urban morphology and air quality (wind speed, CO, and PM_2.5) in residential neighborhoods at the meso-microscale was investigated. The changes in the microclimate and pollutant diffusion distribution in the neighborhood under diverse weather conditions were simulated by Computational Fluid Dynamics (CFD). This study identified five key urban morphological parameters (Building Density, Average Building Height, Standard Deviation of Building Height, Mean Building Volume, and Degree of Enclosure) which significantly impacted the diffusion and distribution of pollutants in the neighborhood. The findings of this study suggested that three specific strategies (e.g. volume of a single building should be reduced, DE should be increased) and one comprehensive strategy (the width and height of the single building should be reduced while the number of single buildings should be increased) could be illustrated as an optimized approach of urban planning to relief the air pollution. The result of the combined effects could provide a reference for mitigating air pollution in sustainable urban environments.     

秦岭山地丹江流域土地利用变化的土壤侵蚀效应评价

论文采用ArcGIS 10.0及InVEST土壤保持模型,分析2000—2010年秦岭山地丹江流域土地利用类型变化特征,模拟流域不同时期不同土地利用类型土壤侵蚀及土壤保持量的变化规律,并着重探讨土地利用类型方式转变对流域土壤侵蚀的影响。结果表明：1）2000—2010年间,流域裸地大比例减少90.18%（831.06 hm²）,主要转移至水域,耕地大面积减少5 197.24 hm²（4.11%）,主要流向灌丛和城镇;坡耕地还林还草初见成效,湿地的保护与恢复成效显著。2）2000—2010年间,流域土壤侵蚀状况较为严重,整体处于中度侵蚀至强度侵蚀级别,但10 a间侵蚀状况有减缓趋势;在该研究时段内,耕地大面积转为灌丛是该流域由土地利用类型变化引起的土壤侵蚀减缓的主要原因;另外,耕地转为林地以及裸地面积的减少也起到了减轻土壤侵蚀的作用;以自然生态系统为主的林地、灌丛及草地转为耕地时,土壤侵蚀强度则会明显增加。3）生态系统土壤保持功能受多方因素共同影响;2000、2010年研究区实际土壤保持量分别为5.35×10⁸、5.47×10⁸ t;占全区面积一半以上的林地和灌丛单位面积土壤保持量较为稳定,全区土壤保持功能有所提高。保证一定面积的林地、在人工干预下合理安排坡耕地还林还草区域的空间分布是秦岭山地丹江流域减少土壤侵蚀的必要措施,同时应注重对可利用耕地的保护。     

沿海城市风暴潮灾害风险评估研究述评

对风暴潮灾害形成机理、风暴潮灾害风险评估方法、灾害风险区划与等级评估、灾害损失评估等方面进行了梳理和分析,认为:①风暴潮灾害风险评估指标体系目前多为主要社会因子和经济损失因子,而忽视主要气象水文指标(最大增水、中心风速等)对风暴潮灾害的影响,研究发现,最大增水和风暴潮灾害呈正相关关系;可通过主成分分析等相关数学模型提取指标因子,避免指标选取主观随意性,又能够客观的确定指标因子的权重;②应建立统一的风暴潮灾害风险评估综合指标;提出建立灾害熵综合风险评估方法,定量的反映所研究区域灾害损失整体水平,灾害熵值也可作为划分灾害等级的分级量度。     

碱预处理污泥产酸效果及其生物群落研究

为了提高污泥水解酸化过程中的挥发酸产量,获取污水脱氮除磷所需的内碳源,以深圳市罗芳污水厂的二沉池污泥为研究对象,采用不同的碱量对其进行预处理。通过测定碱预处理污泥水解酸化过程中的挥发酸浓度,并采用聚合酶链式反应-变性梯度凝胶电泳(polymerase chain reaction denature gradient gel electrophoresis,PCR-DGGE)技术对参与碱预处理污泥水解酸化产酸过程的主要微生物种群进行分析,结果表明,当碱投加量为0.20 g NaOH/g VSS时,初始溶出的蛋白浓度为1 780 mg/L;水解酸化15 d时,挥发酸总量达到3 473 mg/L;参与产酸的主要细菌属于Firmicutes、Proteobacteria、Bacteroidetes三个门类。     

ECONOMIC AND WATER QUALITY EFFECTS OF VARIABLE AND UNIFORM APPLICATION OF NITROGEN1

ABSTRACT: Nitrogen (N) fertilizer rates for achieving optimum crop yields often vary within a field due to spatial variability in soil moisture and nitrogen content and other crop growth factors. When there is substantial within-field variability in these factors, uniform application of N (UAN) may not be economically efficient in terms of maximizing net return because N is likely to be over-applied in some areas and under-applied in other areas of the field. In addition, over-application can adversely affect water quality. A sample of fields in a Midwestern agricultural watershed is used to test for statistically significant differences in N application rates, crop yields, surface and ground water quality and net returns between UAN and variable application of N (VAN) for four cropping systems. Profitability and water quality benefits of VAN are sensitive to the distribution of soil types within a field. Water quality effects and profitability of UAN and VAN vary with cropping systems. VAN is not uniformly superior to UAN in terms of increasing net returns and improving water quality for the farming systems and watershed evaluated in this study.     

Effects of bacterial counts and temperature on the biodegradation of bisphenol A in river water

Total 15 surface river waters were collected from thirteen different rivers to investigate a relationship of bacterial counts and temperature to the degradation of bisphenol A (BPA). Autoclaved and non-autoclaved river water samples were spiked with 0.2 mg/l BPA. The spiked samples were placed at temperatures of 4, 20, and 30 degrees C and analyzed by high performance liquid chromatography. BPA was degraded at all temperatures in the non-autoclaved samples. However, BPA in the autoclaved samples was not changed at all temperatures for 20 d. These results show that the primary factor of BPA degradation in river water is bacteria. Moreover, three groups [group A (> 10000 CFU/ml), group B (2000-10000 CFU/ml), and group C (< 2000 CFU/ml)], were made on the basis of bacterial counts of the samples. Half-lives for BPA degradation in groups A, B, and C were 2, 3, and 6 d at 30 degrees C and were 4, 5, and 7 d at 20 degrees C, respectively. But at 4 degrees C, the loss of BPA was about 40%, 20%, and 10% in groups A, B, and C for 20 d, respectively. Bacterial counts exerted an influence on BPA degradation in river water with temperature. Our results also show that BPA-degrading bacteria are widely distributed in river waters.     

US Army Chemical Corps Vietnam veterans health study: preliminary results

The long-term health consequences of exposure to phenoxyherbicides used in Vietnam has been a great concern to the veterans. In addition to the Air Force Ranch Hand personnel, Army Chemical Corps personnel who served in Vietnam are thought to have had some of the highest herbicide exposures. The Department of Veterans Affairs commenced a study of veterans who served in Vietnam as members of the Army Chemical Corps and a comparison cohort of Army Chemical Corps personnel who served elsewhere. A total of 2872 Vietnam veterans and 2737 non-Vietnam veterans who served in the Army Chemical Corps were identified for inclusion in a telephone health interview survey with a random 20% sample of veterans receiving serum dioxin and other congeners assessments. In a feasibility study which included 284 Vietnam veterans and 281 non-Vietnam veterans, 100 serum assessments were conducted of which 95 were included in the analysis. Vietnam veterans with a history of spraying herbicides were found to have a statistically significant elevation in their current serum 2,3,7,8-TCDD concentrations compared to non-Vietnam veterans without a spray history (P = 0.05). Other 2,3,7,8-substituted dioxins levels were comparable to the levels found in the non-Vietnam veterans. This feasibility study demonstrated that serum dioxin concentrations from a sample of the study participants can be used to identify exposure variables in the health survey that can serve as a surrogate measure of phenoxyherbicide exposure.