填埋场矿化垃圾生物反应床在废水处理中的应用

主要阐述填埋场矿化垃圾的概念、性质和矿化垃圾生物反应床处理废水的机理,介绍了矿化垃圾生物反应床在城市污水、填埋场垃圾渗滤液、畜禽废水、化工废水、含磷废水等各类废水处理中的应用状况,可以看出矿化垃圾生物反应床废水处理技术充分体现了固体废物处理中的“资源化”的原则,既降低了废水处理的成本,又解决了生活垃圾处置的问题,最后结合现状对矿化垃圾生物反应床的前景进行了展望。     

膜生物反应器对白斑综合症病毒的去除研究

研究了不同孔径的膜生物反应器对游离白斑综合症病毒(white spot syndrome virus,WSSV)的截留效果,对不同膜生物反应器的进水、上清液、出水进行荧光定量PCR检测.结果表明,0.45 μm孔径的膜组件对磷酸缓冲液中WSSV的去除量仅0.6 lg;0.22 μm孔径的膜对WSSV病毒的去除量为1.18 lg;0.1 μm孔径的膜对WSSV的去除量为5.5 lg.进一步研究表明,在养殖废水中添加游离的WSSV时,随着时间的延长,膜组件的生物样物质对WSSV去除起了重要的作用;孔径为0.45 μm的膜生物反应器,对WSSV的去除量也达到5.35 lg;3种不同孔径膜生物反应器中运行12h后,对WSSV的去除率并没有显著差异.     

Effect of water-driven changes in rice rhizosphere on Cd lability in three soils with different pH

Pot experiments were conducted to evaluate the effect of water management, namely continuous flooding (CF), intermittent flooding (IF) and non-flooding (NF), on Cd phytoavailaility in three paddy soils that differed in pH and in Cd concentrations. Diffusive gradients in thin films (DGT) technique was employed to monitor soil labile Cd and Fe concentrations simultaneously at three growth stages (tillering, heading and mature stage) of rice. The Cd phytoavailability were generally in the order of NF?>?IF?>?CF, and higher rice Cd (over permitted level, 0.2?mg/kg) were only found in neutral and acidic soils under NF conditions. DGT measured soil labile Cd rather than total Cd was the most reliable predictor for Cd accumulation in rice. CF enhanced the formation of root plaques, which related to oxidation of large quantities of available Fe on root surfaces due to the O₂ secretion of rice root. The Cd concentration in root plaques shared the same trend with DGT-Cd. Generally, root plaques would inhibit Cd uptake by rice under CF conditions, while under IF and NF conditions, root plaques act as a temporarily store of Cd, and soil labile Cd is the key factor that controls the transfer of Cd from soil to rice. The results of principle component analysis revealed that water management had the greatest effect on soil Cd lability and rice Cd in acidic soil. Thus, it is important to consider the availability of Cd and soil pH when assessing current agricultural practices of contaminated soil in China.     

中国西北地区一次典型沙尘过程分析

基于卫星遥感资料、再分析数据、数值模式和中国环境监测数据,分析了2018年4月1～4日中国西北地区一次典型的沙尘爆发、输送过程,并探讨了该次沙尘事件对空气质量的影响。结果表明,该次沙尘事件主要是由冷锋和大风引起的,分为两个阶段:4月1～3日,翻越天山和绕流而至的冷空气与该地暖空气交汇形成冷锋,引起塔克拉玛干沙漠起沙,这些沙尘随西风向东输送,使得哈密、嘉峪关、张掖、武威和兰州等城市PM10、PM2.5质量浓度自西向东依次升高,空气污染加重;4月4日,西北风在地形的作用下风力加大,强风掠过植被稀疏地表产生较强的起沙,西北地区多个城市的PM10、PM2.5质量浓度几乎同时剧增,引发了严重的空气污染。其中,PM10是该次沙尘过程中的主要的大气污染物,是导致空气质量下降的主要原因。     

杭州青山水库沉积物中多环芳烃的垂直分布、来源及潜在生态风险

利用高效液相色谱法检测杭州青山水库沉积物中多环芳烃(PAHs)的含量,并对其垂直分布特征及来源进行分析。结果表明,青山水库沉积物中共检出属于美国EPA优先控制16种PAHs中的15种,主要单体为芘和菲,各采样点位PAHs总量的浓度在324～881 ng/g(干重)之间,平均值为453 ng/g,属低污染水平。ΣPAHs含量空间分布受人类活动影响较大,以游船码头附近点位沉积物中含量最高;垂直尺度方面,各点位沉积物中ΣPAHs含量均是沉积柱中层最高,自水库底层往上呈现增加再减少的变化过程。沉积物中的多环芳烃以高分子量组分为主,其中4环PAHs含量最高,占比34. 3%～45. 6%。通过特征组分比例可确认其主要来自燃烧源,以油料的不完全燃烧形成的污染输入为主。利用沉积物质量基准法、沉积物质量标准法分别对青山水库沉积物中PAHs的风险评价表明,青山水库沉积物尚不存在严重的多环芳烃生态风险,但按照质量标准法评价有PAHs单体含量超过临界效应浓度值,需加强监测查明污染源,并采取措施控制污染物输入。     

Mercury in soil, vegetable and human hair in a typical mining area in China: Implication for human exposure

Concentrations of total mercury(T-Hg) and methylmercury(MeHg) in soil, vegetables, and human hair were measured in a mercury mining area in central China. T-Hg and MeHg concentrations in soil ranged from 1.53 to 1054.97 mg/kg and 0.88 to 46.52 μg/kg, respectively.T-Hg concentrations was correlated with total organic carbon(TOC) content(R~2= 0.50, p0.01)and pH values(R~2= 0.21, p0.05). A significant linear relationship was observed between MeHg concentrations and the abundance of sulfate-reducing bacteria(SRB)(R~2= 0.39, p0.05) in soil.Soil incubation experiments amended with specific microbial stimulants and inhibitors showed that Hg methylation was derived from SRB activity. T-Hg and MeHg concentrations in vegetables were 24.79 – 781.02 μg/kg and 0.01 – 0.18 μg/kg, respectively; levels in the edible parts were significantly higher than in the roots(T-Hg: p0.05; MeHg: p0.01). Hg species concentrations in rhizosphere soil were positively correlated to those in vegetables(p0.01), indicating that soil was an important source of Hg in vegetables. Risk assessment indicated that the consumption of vegetables could result in higher probable daily intake(PDI) of T-Hg than the provisional tolerable daily intake(PTDI) for both adults and children. In contrast, the PDI of MeHg was lower than the reference dose. T-Hg and MeHg concentrations in hair samples ranged from 1.57 to 12.61 mg/kg and 0.04 to 0.94 mg/kg, respectively, and MeHg concentration in hair positively related to PDI of MeHg via vegetable consumption(R~2= 0.39, p0.05), suggesting that vegetable may pose health risk to local residents.     

民用燃煤排放分级颗粒物中碳组分排放因子

中国是全球碳质气溶胶最重要的贡献者之一,民用燃煤排放占有很大的比重.排放因子的不确定性直接影响碳气溶胶排放清单的准确性.本研究基于室内模拟燃烧实验和稀释通道采样系统,采用FA-3型9级撞击采样器采集了3种蜂窝煤(考虑明烧和闷烧)和包括烟煤与褐煤在内的4种块煤燃烧排放的九级粒径颗粒物,采用热光法分析了不同粒径颗粒物中有机碳(OC)和元素碳(EC)的含量,计算得到排放因子.结果表明:(1)对于蜂窝煤的明烧与闷烧,PM2.1中OC排放因子分别为0.07g·kg~(-1)和0.10 g·kg~(-1),EC的排放因子为0.002 g·kg~(-1)和0.001 g·kg~(-1);闷烧排放的有机碳颗粒物高于明烧;元素碳排放因子低于明烧.块煤排放PM2.1中OC与EC排放因子分别是1.4 g·kg~(-1)和0.02 g·kg~(-1),高出蜂窝煤排放一个数量级.(2)粒径分析结果表明,民用煤燃烧排放的颗粒物及其载带的碳组分集中在细颗粒物上,碳组分的质量中值粒径均小于2.5μm,总碳(OC+EC)的排放因子粒径分布表明蜂窝煤燃烧排放的碳组分富集于≤0.43μm粒径段,块煤富集于0.43~0.65μm粒径段.     

柴油机排放颗粒物净化技术研究进展

柴油机被认为是城市大气微粒的主要污染源.柴油机颗粒物组成复杂并且颗粒粒径甚小,大都属于亚微米级粒子和纳米级粒子.因而柴油机颗粒物对人类健康和大气环境的影响受到世人的广泛关注.本文主要对柴油机排放颗粒物的生成机理、化学组成及危害、物理性质、检测方法和净化技术等方面进行综述与探讨.     

多维气相色谱分离TCDDs和PCBs

本文描述用多维气相色谱(SE-54柱/FFAP柱)和FID/ECD并行检测系统分析TCDDs和PCBs的方法。经SE-54柱切割的目的部分立即进入FFAP柱分离,中间不需用冷捕集技术。结果表明,该方法是选择检测复杂环境样品中痕量毒物的有效方法。     

美国汽车清洁燃料研究发展

本文简要介绍了美国汽车清洁燃料和汽油替代燃料的研究和发展状况，内容涉及美国政府对发展汽车清洁燃料的战略、政策、立法和有关发展计划，清洁燃料的类型和种类及应用情况，以及存在的主要问题和未来的发展方向。