太原市某垃圾填埋场渗滤液及周边环境重金属污染及健康风险评估

探讨垃圾渗滤液、填埋场周围土壤和地下水中的重金属污染特征及其对生态环境和人体健康的影响.采集山西省太原市某垃圾填埋场和中转站冬夏季渗滤液、填埋场周边土壤和地下水样本,测定其中重金属含量;分析渗滤液中金属污染的季节性变化;利用健康风险评估模型,估计不同暴露途径下填埋场附近重金属污染对成人和儿童的健康风险.结果表明:(1)夏季填埋场渗滤液(陈年渗滤液)中重金属检出的种类较冬季多.夏季中转站渗滤液(新鲜渗滤液)中检出重金属种类比填埋场中的少,但其金属浓度(除Cr外)较高.(2)土壤重金属平均浓度的顺序为Cu>Cr>Zn>Pb>Ni>As>Hg,地下水中重金属平均含量顺序为Zn>Ni>Cu>Cr>Pb.(3)重金属污染对成人的非致癌总风险在安全阈值内,但对儿童的非致癌总风险接近安全阈值.重金属污染非致癌风险的主要暴露途径为经饮水摄入.有潜在健康风险的重金属主要是As、Pb和Cr.(4)重金属污染对人群的致癌总风险在安全阈值内,主要暴露途径为土壤口食摄入和呼吸吸入.垃圾填埋场和中转站渗滤液中重金属的种类和浓度不同;填埋场附近土壤和地下水中重金属的种类和浓度也有差异.填埋场附近环境的重金属污染对成人和儿童没有健康风险,但有潜在安全隐患.     

Ammonia removal from low-strength municipal wastewater by powdered resin combined with simultaneous recovery as struvite

• Powdered resin was employed for ammonia recovery from municipal wastewater. • Powdered resin achievedefficient ammonia removal under various working conditions. • Co-existing cations indicated competitive adsorption of ammonia. • Ammonia was recoveredby two-stage crystallization coupled with ion exchange. Low-strength municipal wastewater is considered to be a recoverable nutrient resource with economic and environmental benefits. Thus, various technologies for nutrient removal and recovery have been developed. In this paper, powdered ion exchange resin was employed for ammonia removal and recovery from imitated low-strength municipal wastewater. The effects of various working conditions (powdered resin dosage, initial concentration, and pH value) were studied in batch experiments to investigate the feasibility of the approach and to achieve performance optimization. The maximum adsorption capacity determined by the Langmuir model was 44.39 mg/g, which is comparable to traditional ion exchange resin. Further, the effects of co-existing cations (Ca²⁺, Mg²⁺, K⁺) were studied. Based on the above experiments, recovery of ammonia as struvite was successfully achieved by a proposed two-stage crystallization process coupled with a powdered resin ion exchange process. Scanning electron microscopy (SEM) and X-ray diffractometry (XRD) results revealed that struvite crystals were successfully gained in alkaline conditions (pH= 10). This research demonstrates that a powdered resin and two-stage crystallization process provide an innovative and promising means for highly efficient and easy recovery from low-strength municipal wastewater.     

基于危险的事故场景及其形式化描述

事故场景的鉴别是复杂装备系统安全风险分析的基础,其完备性直接影响风险评估的有效性,因为任何事故场景的遗漏即意味着设计上可能存在潜在的事故隐患。提出从鉴别系统危险出发。建立危险与其原因(关联引发事件)、事件与系统要素以及系统各要素之间的映射关系,通过对这些关系的运算来获取事故场景的新方法并给出其形式化表述,以期在理论上确保事故场景鉴别的完备性。     

Combining Renewable Ethyl Cellulose and Acrylate to Fabricate Sustainable TPEs via Controlled Polymerization

Journal of Polymers and the Environment - A series of ethyl cellulose (EC) grafted copolymers were fabricated with methyl methacrylate (MMA), stearyl methacrylate (SMA) and EC grafted...     

混凝土I-II复合型断裂过程声发射特征研究

通过对不同位置预制裂缝的混凝土三点弯曲梁进行声发射试验,开展了不同预制裂缝偏移比下混凝土I-II复合型断裂的声发射过程参数、状态参数、统计参数分布规律,以及参数间相关性研究。结果表明:振铃计数—时间曲线、能量释放率—时间曲线的突变可表征I-II复合型断裂过程的临界状态,随着预制裂缝偏移比的增大,峰值荷载增大,试件脆断性增强;部分声发射过程参数间具有高度或中度相关性;随着裂缝偏移比的增大,试件起裂阶段主频均以低频占优,失稳阶段主频呈现“高—低”趋势。该研究可为混凝土损伤状态判别提供一定基础。     

动态主逻辑图--一种改进的安全风险建模方法

用主逻辑图,可以比较直观地建立起复杂系统的安全风险模型,但是这种模型运用的是布尔代数理论,所以无法模拟具有动态行为的系统.动态主逻辑图就是在主逻辑图的基础上,运用模糊数学（逻辑）的理论,分析复杂系统中的动态行为.介绍了动态主逻辑图的8种基本形态,并以利用动态主逻辑图对系统进行全面诊断和描述系统的部分失效的行为为例,简要说明了动态主逻辑图的新特点.     

水稻壮秧分蘖剂苗期抗冷效果初探

利用人工气候室在苗期施用水稻壮秧分蘖剂对水稻秧苗的形态及生理方面的表现进行了探讨。结果表明：水稻壮秧分蘖剂具有增加秧苗干物重,提高秧苗素质,降低电解质渗出率和提高脯氨酸含量的作用。同时增加了秧苗的分蘖能力和提高水稻产量。     

立体仓库故障自诊断研究

结合立体仓库结构特点 ,分析了立体仓库故障机理 ,构建了立体仓库故障自诊断系统的总体框架 ,并在分析研究其数据采集处理系统、实时监测控制系统及自诊断专家系统的基础上 ,运用VisualBasic6 0在Windows系统下 ,实现了立体仓库故障的自诊断功能     

云南楚雄市水环境对策研究

河流水污染和水资源短缺是楚雄市面临的两大水环境问题。本文将楚雄市社会经济发展、水污染控制和水资源开发利用纳入一个系统,在掌握水环境问题现状和变化趋势及其成因的基础上,探讨河流水质目标和排污控制目标,从宏观协调对策和水污染控制措施两个层次上进行水环境对策的设计和多目标优选,并得到最佳水污染控制实施计划。     

SO_2气敏电极的研制及扩大应用

本文用自制二甲基硅橡胶作为气透膜制成一种SO_2气敏电报,电极的线性响应范围与内充电解质NaHSO_3的浓度有关。CO_2气敏电极可以用SO_2气敏电极骨架将NaHSO_3内充电解质改为NaHCO_3制成。