Preparation,characterization, and Cd(II) sorption of/on cysteine-montmorillonite composites synthesized at various pH

Environmental Science and Pollution Research - Montmorillonite-cysteine could be used as the immobilizer, detector, and detoxifier of heavy metals. To further the understanding and the application,...     

西安城区大气PM_(2.5)中有机碳与元素碳的污染特征

为研究西安市夏、秋、冬3季大气细颗粒物中碳组分的污染变化规律,于2013年夏、秋、冬3季在西安市明城墙内采集大气中的PM2.5样品,测定了样品中的有机碳和元素碳的含量。结果显示,PM2.5中OC和EC的季节平均浓度冬季最高,秋季次之,夏季最低。OC/EC的比值在夏、秋、冬3季均超过2.0,说明采样期间夏、秋、冬3季均存在二次污染。OC/PM2.5的比值夏秋两季差异较小,冬季明显高于夏秋两季;EC/PM2.5的比值在夏、秋、冬3季的变化不大。OC和EC的相关性:夏季秋季冬季。OC与PM2.5的相关程度冬季秋季夏季,且随季节更替变化明显;EC与PM2.5的相关性:秋季夏季冬季。即随着季节变化PM2.5浓度水平整体升高、污染加重时,PM2.5中的OC所占比例明显升高,EC比较稳定,说明受人为影响的二次排放为主要成分的OC对PM2.5贡献更大。     

兰州市地下水氟分布规律及影响因素分析

以地下水污染调查数据为基础,分析兰州市地下水中氟分布规律及影响因素。结果表明氟含量具有浅层地下水大于深部地下水的垂直分带性,由于受人类活动的影响,水平分带性不明显。地层中含氟矿物的溶解是地下水中氟的重要来源,土壤盐渍化成为氟释放的积极促进因素;氟的富集与贫化与水化学特征关系紧密,高硫酸根、钠离子的碱性水环境有利氟的溶解与富集;受径流路径及地形条件的影响,河谷平原区氟含量大于丘陵山地及其边缘地区;工业污染源是引起地下水氟升高的潜在因素,水源地开采对氟分布具有明显的驱动作用。     

Immobilization of lead in anthropogenic contaminated soils using phosphates with/without oxalic acid

Understanding the effects of oxalic acid (OA) on the immobilization of Pb(II) in contaminated soils by phosphate materials, has considerable benefits for risk assessment and remediation strategies for the soil. A series of phosphate amendments with/without oxalic acid were applied to two anthropogenic contaminated soils. We investigated the immobilization of Pb(II) by KH₂PO₄, phosphate rock (PR), activated phosphate rock (APR) and synthetic hydroxyapatite (HAP) at different phosphate:Pb (P:Pb) molar ratios (0, 0.6, 2.0 and 4.0) in the presence/absence of 50 mmol oxalic acid/kg soil, respectively. The effects of treatments were evaluated using single extraction with deionized water or CaCl₂, Community Bureau of Reference (BCR) sequential extraction and toxicity characteristic leaching procedure (TCLP) methods. Our results showed that the concentration of water extractable, exchangeable and TCLP-Pb all decreased with incubation time. The concentration of water-extractable Pb after 120 days was reduced by 100% when soils were amended with APR, HAP and HAP + OA, and the TCLP-Pb was < 5 mg/L for the red soil at P:Pb molar ratio 4.0.Water-soluble Pb could not be detected and the TCLP-Pb was < 5 mg/L at all treatments applied to the yellow-brown soil. BCR results indicated that APRwasmost effective, although a slight enhancement of water-soluble phosphate was detected at the P:Pbmolar ratio 4.0 at the beginning of incubation. Oxalic acid activated phosphates, and so mixing insoluble phosphates with oxalic acid may be a useful strategy to improve their effectiveness in reducing Pb bioavailability.     

Controls on the spatial distribution of iodine in groundwater in the Hebei Plain,China

Environmental Science and Pollution Research - In the Hebei Plain of North China, 70% of the inhabitants depend on groundwater for drinking water. Little is known regarding high-iodine...     

论企业文化与石化行业HSE管理

结合国外石油化工企业管理的实践经验,针对我国石化企业的HSE现状,以企业文化为切入点,论述了如何建设企业健康的HSE文化,从而提升企业HSE管理绩效的问题.     

铁路编组站劳动安全联防联控可靠性模型及应用研究

从个人和群体的可靠性出发，建立了铁路编组站劳动安全联防联控的可靠性模型，论证了联防联控的可行性，提出了实施重点及对策。     

烧结烟气中CO对SO2监测的干扰分析

通过承钢烧结机脱硫出口SO2的比对监测,发现在线及手持监测设备正常但监测数据仍比对不合格。进行CO干扰实验,得出CO对采用＂定电位电解法＂的手持SO2分析仪有正干扰,并得出了干扰系数。现场实地测试后,利用干扰系数对监测数据进行人工修正,对比结果合格。应用＂定点位电解法＂监测烧结机烟气中低浓度SO2时,应人工修正或加装剔除CO影响的元件。     

浅议施工总承包企业HSE管理体系的实施

结合我国施工单位的现状,以管理水平的提升和与相关方的合作为切入点,论述了施工总承包企业如何有效实施HSE管理体系的问题.