苯系物事故应急救援避免环境污染的对策探讨

分析了在苯系物事故应急救援中,苯系物事故应急救援对环境造成的影响,提出了避免造成环境污染的对策。     

铅元素人为循环环境释放物形态分析

环境中铅污染物来自于物质人为循环的环境释放,铅释放物的形态差异意味着其在环境介质中迁移和转化的起始状态不同.确定铅元素人为循环环境释放物的形态,可以为环境风险评估和源头管理提供科学依据.本研究通过追踪铅元素人为循环流动过程,应用物理化学分析方法,辨识生命周期各阶段环境释放物中铅元素的形态,并以2010年为例,定量分析中国铅元素人为循环中环境释放物的形态分布特征.结果表明,2010年中国铅人为循环中环境释放物主要形态表现为PbSO4,约占总量的23.4%;其次是PbO、Pb和PbCO3,共占总释放量的46.2%.国内每消费1 kt精铅,将向环境释放547.9 t的铅,这些环境释放物中73.3%来源于产品使用阶段和废物处置与回收阶段;从形态看,PbSO4占释放物的量为128.2 t,主要来源于生产阶段和废物处置与回收阶段,PbO、Pb和PbCO3则分别主要来源于废物处置与回收、产品使用和生产几个阶段.     

苯系物污染土壤热解析实验研究

采用静态实验研究了苯系物(BTEX)污染土壤热解析的影响因素,确定了最优的热解析条件,然后通过动态实验,考察了热解析技术修复苯系物污染土壤的效果。结果表明:在加热温度为120℃、粒径水平≤2.0 mm以及加热时间为45min的条件下,污染土壤中总BTEX去除率达到97.3%,其中苯和甲苯的去除率在99%以上,乙苯、间对二甲苯和邻二甲苯的去除率在95.6%~97.2%,修复效果非常理想。     

Characteristics of ozone and ozone precursors (VOCs and NOx) around a petroleum refinery in Beijing, China

A field measurement campaign for ozone and ozone precursors(VOCs and NOx) was conducted in summer 2011 around a petroleum refinery in the Beijing rural region. Three observation sites were arranged, one at southwest of the refinery as the background, and two at northeast of the refinery as the downwind receptors. Monitoring data revealed the presence of serious surface O3 pollution with the characteristics of high average daily mean and maximum concentrations(64.0 and 145.4 ppbV in no-rain days, respectively) and multi-peak diurnal variation. For NOx, the average hourly concentrations of NO2 and NO were in the range of 20.5–46.1 and 1.8–6.4 ppbV, respectively. For VOC measurement, a total of 51 compounds were detected. Normally, TVOCs at the background site was only dozens of ppbC, while TVOCs at the downwind sites reached several hundreds of ppbC. By subtracting the VOC concentrations at background, chemical profiles of VOC emission from the refinery were obtained, mainly including alkanes(60.0% ± 4.3%), alkenes(21.1% ± 5.5%) and aromatics(18.9% ± 3.9%). Moreover, some differences in chemical profiles for the same measurement hours were observed between the downwind sites; the volume ratios of alkanes with low reactivity and those of alkenes with high reactivity respectively showed an increasing trend and a decreasing trend. Finally, based on temporal and spatial variations of VOC mixing ratios, their photochemical degradations and dispersion degradations were estimated to be 0.15–0.27 and 0.42–0.62, respectively, by the photochemical age calculation method, indicating stronger photochemical reactions around the refinery.     

北京官厅水库中农药类内分泌干扰物分布和来源

研究了北京官厅水库中农药类内分泌干扰物污染水平、分布特点和来源.结果表明,官厅水库及其支流水体受到农药类内分泌干扰物轻度污染.从农药在官厅水库中的分布推断,官厅水库以及各支流周边地区及农田排水渠是水库中农药的重要来源.底泥中农药通过底泥孔隙向表面水扩散,是表面水农药的1个污染源.由于水库周边较多的农业活动,可能导致水中农药浓度提高.为了减少污染和水生生物对内分泌干扰物的暴露,需要进行定期监测,减少农药的使用和农事操作.     

不同湿地植物凋落物对汞铊矿废弃物浸出酸性废水中重金属的吸附研究

研究了不同湿地植物(稻草(Oryza sativa L.)、风车草(Cyperus involucratus Rottb.)、芦竹(Arundo donax L.)、美人蕉(Canna indica L.)、水葱(Scirpus validus Vahl.)、香蒲(Typha orientalis C.Presl)和鸢...     

典型区域历史遗留土壤污染问题及其综合防治研究

土壤污染是历史遗留环境问题的众多表现形式之一.土壤污染引发的土壤环境质量恶化,直接影响到人居环境安全、人体健康和社会稳定.本文通过对贵州铜仁汞矿产历史遗留问题区域土壤污染综合防治方案的分析研究,明确了土壤污染综合防治原则,并分别给出了实现污染源控制、土壤污染修复治理以及农产品安全与环境健康监管的路线图,为其它历史遗留问题区编制和实施土壤污染综合防治规划提供参考.     

二级膜分离—冷凝—吸附工艺处理石化罐区废气

采用二级膜分离—冷凝—变压吸附工艺回收处理含有高浓度挥发性有机物和苯系物的炼厂罐区外排"呼吸气"。结果表明,进气的非甲烷总烃质量浓度范围41 000～182 000 mg/m~3,进气中苯、甲苯和二甲苯的质量浓度分别为400～1 400 mg/m~3,150～1 600 mg/m~3,300～2 100 mg/m~3时,尾气中非甲烷总烃质量浓度始终低于80mg/m~3,去除率均高于99.9%,苯、甲苯和二甲苯的去除率分别为99.6%、99.6%和99.8%。抗冲击负荷实验将进气量提高50%,尾气中非甲烷总烃质量浓度仍低于80 mg/m~3。二级膜单元可以高效浓缩轻烃,既回收获得可燃气,又解决了轻烃积累所造成的尾气超标难题。