Life cycle–based,energy-related analysis for waste management strategies: a case study of two impact indicators in Pyongyang

Environmental Science and Pollution Research - Municipal solid waste (MSW) is regarded to be an important source of greenhouse gas emissions, which could result in a significant impact on climate...     

针对高溶解氧、高锰酸盐指数的地表水水质评估方法研究

在进行水体研究的过程中,选择适当的评估方法对水体进行评估必不可少。为寻找更加适用于高溶解氧、高锰酸盐指数较高的水体的水质评估模式,在分析现有水质评估方法的基础上,对评价安全性最高的单因子评价法和最能体现生态修复能力的有机污染综合指数评价法进行了比较分析,建立了单因子-有机污染综合指数耦合方法,建立了基于两种方法联合使用的水质分析模式。利用监测数据,分析了该模型应用于高溶解氧与高锰酸盐指数的地表水水质评估的可行性。结果表明,该方法适用于高溶解氧、高锰酸盐指数的地表水水质评估。     

基于文献计量分析的长江经济带农田土壤重金属污染特征

长江经济带是我国重大战略发展区域之一,理清长江经济带农田土壤重金属污染特征与来源对区域土壤重金属污染防控和农业安全生产具有重要意义.在检索文献数据的基础上,结合空间分析和地累积指数法分析了长江经济带农田土壤重金属（Cd、Cr、Hg、As、Pb、Cu、Zn和Ni）的污染特征、环境风险和主要来源.结果表明：①农田土壤Cd、Cu、Pb、Hg、Zn和As超过农用地土壤污染风险筛选值的比例分别为39.8%、18.5%、8.3%、6.9%、6.9%和6.4%,其中土壤Cd的超标比例最高;②不同区域农田土壤重金属空间分异明显,上游土壤Cr、Cu、Zn和Ni含量高于中游和下游地区,中游土壤Cd、As和Pb含量高于上游和下游地区;③研究区8种重金属的地累积指数分别为：Cd （0.42）>Hg （-0.28）>Pb （-0.32）>Zn （-0.39）>Cu （-0.42）>Cr （-0.7）>As （-0.81）>Ni （-0.73）,其中土壤Cd和Hg地累积风险最高;④长江经济带中上游地区农田土壤重金属累积主要受地质高背景和矿山开采等因素影响,中下游地区主要受到快速城镇化、工业生产和高强度农业利用等因素的影响.针对长江经济带农田土壤重金属污染现状及管控需求,建议加强农田土壤重金属的源头防控,根据重金属污染程度、地质背景和农产品质量等进行农田土壤重金属污染的分区分级管控和分类管理,以期实现长江经济带农田土壤环境质量安全和农业绿色可持续生产.     

基于地基太阳光度计观测的长安区气溶胶光学特性变化及其与颗粒物浓度的关系

气溶胶地基观测数据和颗粒物浓度数据的同步定量评估可为了解长安区大气污染的垂直分布特征,制定合理的大气污染控制提供更有效的依据.基于CE-318太阳光度计观测数据,分析了2018年10月～2021年4月西安市长安区月均和季均气溶胶光学特性分布和变化特征,结合近地面颗粒物浓度数据,分析了不同季节、不同污染程度下气溶胶光学厚度（AOD）对颗粒物浓度的响应.结果表明：（1）观测期间长安区AOD季节变化分明：秋季（1.02）>冬季（1.00）>夏季（0.63）>春季（0.47）; AOD月度、年际差异大,2019年AOD（0.51）略高于2020年（0.48）.（2）整个观测期间长安区气溶胶主控模态存在明显的季节、月度差异,从春季到冬季气溶胶主控模态逐渐从粗模态向细模态转变;2019年气溶胶主控模态的季节变化与整个观测时段类似,2020年各季节气溶胶Angstrom波长指数（Angstrom）分布稳定,气溶胶粒子均以粗模态的形式存在;整个观测时段来看长安区气溶胶类型以混合型气溶胶为主.（3）AOD和Angstrom的关系存在明显的季节差异,春季大气污染以粗模态的气溶胶粒子为主导...     

黄土地层浅埋暗挖隧道松散围岩压力计算*

为研究黄土地层浅埋暗挖隧道松散围岩压力特征,根据既有隧道施工现场裂缝扩展情况,假定隧道开挖后的土体存在破裂区,取一半破裂区土体进行静力极限平衡分析,考虑静止土压力、侧向土压力、隧道尺寸和土层参数对半结构的影响,推导出适用于黄土地层浅埋暗挖隧道的围岩压力解析式,确定该公式下的隧道深浅埋划分界限,并结合工程实例分析隧道埋深、静止土压力系数和侧压力系数对围岩压力的影响。研究结果表明:随隧道埋深增大,围岩压力存在峰值,围岩压力曲线呈先增大后减小的趋势;围岩压力随静止土压力系数和侧压力系数的增大而减小,但静止土压力系数对围岩压力的影响较大;将新方法得到的围岩压力值分别与现场实测值和既有理论围岩压力值进行对比,计算的垂直、侧向围岩压力值均大于实测值,且新方法的计算误差相对较小。     

Gasification applicability study of polyurethane solid refuse fuel fabricated from electric waste by measuring syngas and nitrogenous pollutant gases

To recycle polyurethane foam waste generated from electric appliance recycling centers for use as fuel in a gasification process, polyurethane solid refuse fuel fabricated as pellets was analyzed for the characteristics of elemental composition, proximate analysis, heating value, and thermo-gravimetric testing. It has a high heating value of 29.06 MJ/kg with a high content of combustibles, which could be feasibly used in any thermal process. However, the nitrogen content, of up to 7 %, was comparably higher than for other fuels such as coal, biomass, and refuse-derived fuel, and may result in the emission of nitrogenous pollutant gases of HCN and NH₃. By conducting gasification experiments on polyurethane solid refuse fuel in a fixed-bed reactor, a syngas with a heating value of 9.76 kJ/m³ and high content of both H₂ and CO were produced with good gasification efficiency; carbon conversion 54 %, and cold gas efficiency 60 %. The nitrogenous pollutant gases in syngas were measured at the concentrations of 160 ppm hydrogen cyanide and 40 ppm ammonia, which may have to be reduced using proper cleaning technologies prior to the commercialization of gasification technology for polyurethane waste.     

氧化-混凝工艺处理碱性含砷废水的技术改造

针对某锑冶炼厂已有氧化-混凝法处理碱性含砷废水工艺中存在的药剂成本较高的问题,通过将氧化剂由双氧水改为次氯酸钠,将混凝剂由硫酸铁改为聚合硫酸铁,并采用二次混凝工艺,得出了废水处理效率和药剂成本的变化情况。结果表明,经技术改造后的工艺能在保证废水处理效率的前提下,使药剂成本有较大幅度的下降。     

Characteristics of typical dissolved black carbons and their influence on the formation of disinfection by-products in chlor(am)ination

● The physicochemical and structural properties of DBC were characterized. ● The effects of DBC on DBPs and DBPFP generation during disinfection were evaluated. ● The DBPs and DBPFP generation during chlor(am)ination were compared. Dissolved black carbon (DBC) released from biochar can be one of the potential disinfection by-products (DBPs) precursors in the dissolved organic matter pool. However, the physiochemical and structural properties of DBC and the effects on the development of DBPs and DBP formation potential (DBPFP) during the disinfection process remain unclear. In this study, the characteristics of two kinds of DBC, namely, animal-derived DBC (poultry litter DBC, PL-DBC) and plant-derived DBC (wheat straw DBC, WS-DBC), were investigated. The effects of different kinds of DBC on the evolution of DBPs and DBPFP in chlorine and chloramine disinfection processes were compared with natural organic matter (NOM). The results showed that the total DBPs concentrations derived from PL-DBC, WS-DBC and NOM were similar during chlorination (i.e., 61.23 μg/L, 64.59 μg/L and 64.66 μg/L, respectively) and chloramination (i.e., 44.63 μg/L, 44.42 μg/L and 45.58 μg/L, respectively). The lower total DBPs and DBPFP concentrations in chloramination could be attributed to the fact that the introduction of ammonia in chloramine inhibited the breaking of the bond between the disinfectant and the active group of the precursor. Additionally, DBC presented much lower total DBPFP concentrations than NOM in both chlorination and chloramination. However, both kinds of DBC tended to form more monochloroacetic acids and haloacetamides than NOM, which could result from the higher organic strength, higher protein matter, and nitrogen-rich soluble microbial products of DBC.     

Removal Efficiency of PM10 via Ventilation with Residential Exhaust Hood and Conditions for Reducing Human Intake Fraction

Environmental Modeling & Assessment - As the number of enclosed residential buildings increases to minimize energy consumption, research on indoor air quality is becoming more important....     

A Compatible Interface of Wheat Straw/Polylactic Acid Composites Collaborative Constructed Using KH570–Nano TiO2

Journal of Polymers and the Environment - Poor interfacial compatibility between wheat straw and polylactic acid (PLA) remains a problem that directly affects the overall performance of wheat...