阳极氧化联合电-Fenton氧化深度处理垃圾渗滤液

采用多孔碳素阴极、Ti/SnO2-Sb2O5-IrO2阳极构建电化学氧化系统用于渗滤液的深度处理。研究结果表明,所构建的电化学氧化系统通过阳极氧化和电-Fenton氧化2种机制降解有机污染物;处理过程中阴极表面形成的沉淀物对TOC和COD的衰减也产生了影响。在阴极电位为-1.0 V、Fe2+初始浓度为0.5 mmol/L的条件下,电化学处理120 min获得了58%的TOC去除;处理480 min COD去除率为55%,NH3-N去除率为99%,TN去除率为60%,色度几乎被完全去除。GC-MS分析结果表明,渗滤液中以腐殖质类物质为主的有机化合物被降解为分子量相对较小的有机物,直至完全矿化。联合阳极氧化和电-Fenton氧化机制的电化学处理方法为垃圾渗滤液深度处理提供了新的选择。     

Vinegar residue compost as a growth substrate enhances cucumber resistance against the Fusarium wilt pathogen Fusarium oxysporum by regulating physiological and biochemical responses

Environmental Science and Pollution Research - Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. cucumerinum (FOC) is the most severe soil-borne disease attacking cucumber. To assess the...     

Greenhouse gas emissions from dairy open lot and manure stockpile in northern China: A case study

The open lots and manure stockpiles of dairy farm are major sources of greenhouse gas (GHG) emissions in typical dairy cow housing and manure management system in China. GHG (CO₂, CH₄ and N₂O) emissions from the ground level of brick-paved open lots and uncovered manure stockpiles were estimated according to the field measurements of a typical dairy farm in Beijing by closed chambers in four consecutive seasons. Location variation and manure removal strategy impacts were assessed on GHG emissions from the open lots. Estimated CO₂, CH₄ and N₂O emissions from the ground level of the open lots were 137.5±64.7 kg hd^-1 yr^-1, 0.45±0.21 kg hd^-1 yr^-1 and 0.13±0.08 kg hd^-1 yr^-1, respectively. There were remarkable location variations of GHG emissions from different zones (cubicle zone vs. aisle zone) of the open lot. However, the emissions from the whole open lot were less affected by the locations. After manure removal, lower CH₄ but higher N₂O emitted from the open lot. Estimated CO₂, CH₄ and N₂O emissions from stockpile with a stacking height of 55±12 cm were 858.9±375.8 kg hd^-1 yr^-1, 8.5±5.4 kg hd^-1 yr^-1 and 2.3±1.1 kg hd^-1 yr^-1, respectively. In situ storage duration, which estimated by manure volatile solid contents (VS), would affect GHG emissions from stockpiles. Much higher N₂O was emitted from stockpiles in summer due to longer manure storage.

Implications: This study deals with greenhouse gas (GHG) emissions from open lots and stockpiles. It’s an increasing area of concern in some livestock producing countries. The Intergovernmental Panel on Climate Change (IPCC) methodology is commonly used for estimation of national GHG emission inventories. There is a shortage of on-farm information to evaluate the accuracy of these equations and default emission factors. This work provides valuable information for improving accounting practices within China or for similar manure management practice in other countries.     

铋电极差分脉冲伏安法测定水中痕量2,4-二硝基苯肼

以自制铋电极作为工作电极,建立了铋电极差分脉冲伏安法测定2,4-二硝基苯肼的分析方法。实验结果表明：以0.1 mol/L NaOH+0.1 mol/L KCl混合溶液（pH=13.0）配制测定底液,在扫描速率为100 mV/s的条件下,2,4-二硝基苯肼于-0.53 V处产生灵敏的氧化峰;在2,4-二硝基苯肼浓度为3.0×10-8~1.0×10-5 mol/L范围内,空白和试样的氧化峰电流强度差值与对应2,4-二硝基苯肼浓度的对数呈良好的线性关系,检出限达8.37×10-9 mol/L;将该方法应用于工业废水中痕量2,4-二硝基苯肼的检测,回收率为95.6%~103.1%,相对标准偏差小于3%。     

十三烷基苯磺酸钠和辛基酚聚氧乙烯醚二元复配溶液的定量分析

采用向十三烷基苯磺酸钠（STBS）和非离子表面活性剂辛基酚聚氧乙烯醚（OP-10）二元复配溶液中添加β-环糊精（β-CD）的方法,降低STBS和OP-10之间定量检测时的相互干扰。实验结果表明：添加β-CD时,可提高STBS的检测准确性,降低STBS对OP-10的检测干扰;在二元复配溶液中,STBS和OP-10的方法回收率分别在100.8%~102.0%,97.4%~102.2%之间,检测误差分别在2.0%和2.6%以内;Cl^-,SO₄^2-,Na⁺,Ca²⁺的存在对二元复配溶液中STBS和OP-10的检测干扰可忽略;将该方法应用于地层水水样中,仍可准确定量分析STBS和OP-10的含量。     

铁铈钛复合氧化物催化剂的制备及其选择性催化还原NO的性能

采用共沉淀法制备了一种新型催化剂——铁铈钛复合氧化物催化剂,研究了Fe掺加量、体积空速以及H2O和SO2的加入对其选择性催化还原NO性能的影响;采用XRD和SEM等手段对催化剂的结构和形貌进行了表征。表征结果显示,Fe的掺加使催化剂表面的颗粒更均匀,提高了催化剂的分散度。实验结果表明：以Ce（NO3）3,Fe（NO3）3?9H2O,TiOSO4?2H2O为原料、按n（Ce）∶n（Fe）∶n（Ti）=0.2∶0.8∶1配比制得的Ce0.2Fe0.8TiOx为催化剂,在反应温度250 ℃、反应时间3 h、体积空速25 000 h-1的条件下,NO去除率为99.8%,N2选择性为100%;Fe的掺加显著提高了Ce0.2Fe0.8TiOx催化剂的抗H2O和SO2的能力。     

Occurrence of free estrogens,conjugated estrogens,and bisphenol A in fresh livestock excreta and their removal by composting in North China

An efficient pretreatment and analytical method was developed to investigate the occurrence and fate of four free estrogens (estrone (E1), 17β-estradiol (17β-E2), estriol (E3), and 17α-ethinylestradiol (EE2)), four conjugated estrogens (estrone-3-sulfate sodium salt (E1-3S), 17β-estradiol-3-sulfate sodium salt (E2-3S), estrone-3-glucuronide sodium salt (E1-3G), and 17β-estradiol-3-glucuronide sodium salt (E2-3G)), and bisphenol A (BPA) in three livestock farms raising beef cattle, cows, sheep, swine, and chickens in Qi County, which is located in North China. The results demonstrated that one cow and one beef cattle excreted 956.25–1,270.41 and 244.38–319.99 μg/day of total (free and conjugated) estrogen, respectively, primarily through feces (greater than 91 %), while swine excreted 260.09–289.99 μg/day of estrogens, primarily through urine (98–99 %). The total estrogen excreted in sheep and broiler chicken feces was calculated to be 21.64–28.67 and 4.62–5.40 μg/day, respectively. It was determined that conjugated estrogens contributed to 21.1–21.9 % of the total estrogen excreted in cow feces and more than 98 % of the total estrogen excreted in swine urine. After composting, the concentration of total estrogen decreased by 18.7–59.6 %; however, increased levels of BPA were measured. In treated compost samples, estrogens were detected at concentrations up to 74.0 ng/g, which indicates a potential risk of estrogens entering the surrounding environment.     

S-K型管式混合器-微絮凝高速过滤的实验研究

基于2种传统管式混合器的特点,研究了苏尔士-凯尼斯（S-K）新型组合管式混合器在预氧化-微絮凝高速过滤技术中的应用,对苏尔士（Sulzer）管式混合器、凯尼斯（Kenics）管式混合器及s-K型管式混合器高速过滤出水水质进行了对比分析,结果表明,S-K型微絮凝方式对浊度、COD及TP的平均去除率比其他2种混合器混合方式的去除效果提高了5％～10％,分别为80．3％、64．76％和51．15％。S-K型混合器过滤形成的絮体能够充分利用深层滤料,延长过滤周期。     

钝化剂在烟草植物修复铅镉污染土壤中的作用

重金属钝化剂可以改变土壤中重金属的形态,降低其在土壤中的有效浓度、植物毒性及生物有效性,影响污染土壤中植物的生长及其对重金属的吸收。在温室盆栽条件下研究了施加羟基磷灰石（HA）、纳米羟基磷灰石（nHA）、纳米零价铁（nFe0）和纳米TiO2（nTiO2）对烟草植物修复铅镉污染土壤的作用。结果表明,HA降低土壤中Ph、cd的有效性、促进烟草生长、增加了烟草叶、茎、根中cd的吸收量和根系中Pb的吸收量,有利于Ph、cd的钝化和植物修复。nHA也可以降低土壤中Pb、cd的有效性,增加了烟草叶中cd的吸收量,有利于Pb、cd的钝化和cd的植物提取。nFe0和nTiO2：对于土壤Pb和cd的钝化作用和植物修复均没有显著影响。综合来看,HA最适合应用于烟草植物修复铅镉污染土壤。     

长江中游城市群综合发展水平时空分异研究

区域可持续发展理念已被社会各界所接收,并逐步深入到社会发展计划及区域政策制定中。以区域差异分析为基础的区域格局优化是促进区域发展的核心内容。从经济发展、资源利用、环境保护、人口与公共服务和科技创新等5个方面选取23个指标,构建其监测评估指标体系综合分析长江中游城市群综合发展水平时空格局演变,有助于认清长江中游城市群综合发展格局形成的过程,出现的问题及产生的原因,从而制定相应的区域调控政策,这对于促进长江中游城市群内部区域之间协调发展及推进中部崛起战略具有重要的现实意义。基于2005年和2011年长江中游城市群37个地级市的统计数据,借助SPSS、GIS软件,采用全局主成分分析法评价分析其综合发展水平及时空分异,并对其成因进行分析。结果表明：区域综合发展分值有所提升,但增长潜力仍然很大;发展水平差异显著,且两极分化趋势明显;整体呈现出以武汉和长沙为中心,以南昌、合肥为副中心发展格局,但中心城市带动作用较弱,制约各城市群发展的因素各异。因此,未来长江中游城市群应努力提升区域经济发展总量的同时,转变经济产业结构,加强企业创新能力,寻求新的经济增长点。与此同时,应加大基础设施尤其是道路交通的投资强度;充分利用已有的地理区位及资源、科技人才优势发展第二、三产业,提高经济发展中资源的利用效率,降低能耗,保护环境;除此之外,还应加强区域宏观调控,注重城乡统筹发展,协调、平衡区域内部均衡发展,缩小区域之间及内部差异,促进技术转移和优势互补