气氛对垃圾焚烧中重金属迁移特性的影响

对城市生活垃圾焚烧过程中Ni、Cd、Cu、Pb、Cr和Zn 6种重金属在不同气氛中的挥发率进行了研究,同时比较了氧化性气氛和还原性气氛、中性气氛和酸性气氛以及在混合气氛中各重金属的挥发率。结果表明,氧化性和还原性气氛对Ni、Cu和Cr挥发影响较大,Cr、Cd、Pb和Zn在还原气氛下挥发率比在氧化气氛下高,而Ni和Cu则...     

Occurrence of diarrheagenic Escherichia coli genes in raw water of water treatment plants

Purpose

The high incidences of waterborne diseases are frequently associated with diarrheagenic Escherichia coli (DEC). DEC may pose a health risk to people who contact surface water for recreation or domestic use. However, there is no published report on the monitoring of DEC in drinking water sources in Taiwan. In this study, the occurrence of DEC genes in raw water for water treatment plants in Taiwan was investigated.

Method

Raw water samples were taken from water treatment plants adjacent to the Kaoping River in southern Taiwan. Each water sample was treated with membrane filtration followed by DNA extraction from the concentrate and concentrate enrichment, respectively. The target genes for various DEC strains of genes were identified, including enteroaggregative E. coli (EAEC), enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC).

Results

Among 55 water samples analyzed, DEC genes were detected in 16 (29.1%) samples. Strain-specific genes for EAEC, EHEC, EIEC, and EPEC were found in the percentages of 3.6%, 10.9%, 9.1%, and 9.1%, respectively. The specific gene for ETEC is not detected in the study. By looking at the presence/absence of specific genes and water sample characteristics, water temperature was found to differ significantly between samples with and without EHEC gene. In addition, pH levels differed significantly for EHEC and EPEC presence/absence genes, and turbidity was significantly different for water with and without EPEC genes.

Conclusion

DEC genes were detected in 29.1% of the raw water samples in the study location. The potential health threat may be increased if the treatment efficiencies are not properly maintained. Routine monitoring of DEC in drinking water sources should be considered.     

树脂吸附-Fenton 试剂氧化法预处理炼油碱渣废水

采用树脂吸附-Fenton 试剂氧化组合工艺对某炼油企业炼油碱渣废水进行预处理.实验确定的最佳工艺条件为:3 种树脂串联吸附,废水流量0.33 mL/ min,H2O2加入量0.20 mol / L,n（H2O2）1 n（Fe2 +）= 12,Fenton 试剂氧化进水pH 3,Fenton 试剂氧化反应时间120 m...     

唐山市概况和灾害潜势分析

本文概述了唐山市的基本情况及其经受的自然灾害和发展趋势,这些内容为制定唐山市综合减灾规划的前提和基础。     

AN INTEGRATED ONE‐DIMENSIONAL AND TWO‐DIMENSIONAL URBAN STORMWATER FLOOD SIMULATION MODEL1

ABSTRACT: Flash flooding is the rapid flooding of low lying areas caused by the stormwater of intense rainfall associated with thunderstorms. Flash flooding occurs in many urban areas with relatively flat terrain and can result in severe property damage as well as the loss of lives. In this paper, an integrated one‐dimensional (1‐D) and two‐dimensional (2‐D) hydraulic simulation model has been established to simulate stormwater flooding processes in urban areas. With rainfall input, the model simulates 2‐D overland flow and 1‐D flow in underground stormwater pipes and drainage channels. Drainage channels are treated as special flow paths and arranged along one or more sides of a 2‐D computational grid. By using irregular computation grids, the model simulates unsteady flooding and drying processes over urban areas with complex drainage systems. The model results can provide spatial flood risk information (e.g., water depth, inundation time and flow velocity during flooding). The model was applied to the City of Beaumont, Texas, and validated with the recorded rainfall and runoff data from Tropical Storm Allison with good agreement.     

含镍废催化剂的回收利用

介绍了从含镍废催化剂中以硝酸镍形式加收镍的方法，镍回收率为70％，硝酸镍纯度为96．6％。该工艺简单，具有较好的经济效益和环境效益。     

混凝沉淀-二氧化氯氧化法处理印染废水

介绍了混凝沉淀－ＣｌＯ２氧化法处理印染废水的反应机理,工艺流程,处理效果及经济效益分析。在２个工厂的实际应用表明,该法工艺简单,操作方便,投资少,效果好。     

炼油催化剂废渣污染及其防治的研究

对炼油厂裂化催化剂废渣和加氢精制催化剂渣的污染成分和污染状况进行了分析,结果表明,排放到大气中的裂化催化剂微粒含有０．５５％的Ｎｉ和０．１８％的Ｖ,已造成大气污染,裂化催化剂废渣经雨水淋洗后,其中部分Ｎｉ和Ｖ会进入水环境,造成污染。     

Quantifying the global fractionation of polychlorinated biphenyls

Due to the wide range of their physical-chemical properties, polychlorinated biphenyls (PCBs) have played an important role in the derivation of the global fractionation hypothesis, which predicts changes in the composition of persistent organic pollutant mixtures with latitude. Recent historical emission estimates, the derivation of an internally consistent property data set, in combination with a zonally averaged global fate and transport model, allow a quantitative investigation of the compositional shifts PCBs experience as a function of environmental compartment, latitude and time. Model simulations reproduce the higher relative abundance of lighter PCB congeners with increasing latitude, observed in air and soil, and quantify the relative importance of partitioning, persistence and emissions in establishing PCB patterns. Compositional variations consistent with global fractionation, as well as inverted concentration profiles with higher levels in the Arctic than at lower latitudes, are consistent with only minor fractions of the global PCB inventory being transferred northward.     

带防腐层在役压力容器表面磁粉探伤灵敏度的试验研究

采用人工裂纹试样的方法 ,模拟压力容器涂刷油漆防腐层的状况进行磁粉探伤 ,得出了油漆防腐层厚度与裂纹检出灵敏度的定量关系 ;结合CVDA《压力容器缺陷评定》规范 ,探讨了试验方法对一般在役压力容器带有油漆的情况下 ,进行磁粉探伤检验的可行性。研究表明 :采用交流磁化法进行探伤 ,当漆层厚度大约小于2 5 0 μm时 ,灵敏度影响较小 ,同时亦表明不宜使用直流磁化方法。该结论对承受低应力工况条件下的压力容器安全质量检验和评估 ,具有重要参考价值