新生产空调客车内挥发性有机物浓度水平和来源分析

选取某厂家新生产的、下线时间不超过28d的53座新空调客车,在车辆处于静止状态下采用二次热解析-毛细管气相色谱/质谱联用法测量新空调车内挥发性有机物的分布特征和浓度水平.根据NIST02标准谱图进行匹配检索,结合色谱保留时间定性,共定性检出33种挥发性有机物,包括烷烃(15种、45.4%)、芳香类化合物(9种、27.3%)、醇(4种、12.1%),酮(3种、9.1%)、酯(2种、6.1%),且大多集中在C6～C10的范围内.新车内浓度最高的前5种挥发性有机物分别为癸烷(8.01 mg/m3)、3-甲基己烷(7.10mg/m3)、庚烷(5.10mg/m3)、异庚烷(4.20 ms/m3)和1-甲基,3-乙基苯(3,56 mg/3),总挥发性有机物TV012,52.5mR/m3.烷烃主要来源于空调车内部保温材料如聚氨酯(PU)发泡海绵或者聚乙烯(PE)发泡材料的释放,而车内检出的芳香族化合物主要来自汽车内饰用胶粘剂、密封胶等的释放.     

几种医疗垃圾处理技术综述

医疗废物是一类危害极大的特殊废物。自20世纪50年代起,医疗废物的处理已引起世界各国的广泛重视。目前,国内外学者对医疗废物处理技术的研究日益丰富,已经取得了一定的研究成果。在此基础上,通过综合比较焚烧处理、高压蒸汽灭菌处理、化学处理、微波处理、热解处理等几种医疗废物处理技术,综合评定了各种处理工艺的技术参数及优缺点,最后比较分析得出了高温热解法具有多方面的优点,是目前国内外首推的医疗废物处理技术。     

复合混凝剂用于夏季太湖水混凝脱浊研究

用特征粘度系列化的聚二甲基二烯丙基氯化铵(PDM)与聚合氯化铝(PAC)复合得到稳定的复合混凝剂,用于夏季高藻太湖水强化混凝脱浊处理.通过混凝烧杯实验.考察了无机/有机复合比例、PDM特征粘度对脱浊效果及絮团沉淀性能的影响.结果表明,对浊度为30-33 NTU,温度为28～30℃,藻含量为2.6×107个儿的太湖水,在与某市水厂混凝强度相近的搅拌强度下.当达到该水厂2NTU沉淀池出水的余浊标准时,PAC需7.00 mg/L的投加量.质量复合比例为5:1、10:1、20:1的PAC(以Al2O3计)/PDM复合混凝剂所需PAC投加量随PDM特征粘度0.52、1.53、2.46 dL/g的增加分别为3.00-2.83 ms/L、3.50-3.49ms/L、5.37-4.67 mg/L,相对于PAC减少投加量57.14%-59.57%、50%-50.14%、23.29%-33.29%;作为深度处理的技术准备.当沉淀出水浊度要求提高至1NTU的情况下,复合药剂依然可发挥好的作用,PAC需10 mg/L的投加量,PAC(以Al2O3计)与PDM质量复合配比为20:1、10:1、5:1的复合混凝剂需8.33-3.91 mg/L的投加量,能比PAC减少投加量16.7%～60.9%.可见,PDM明显提高了PAC的混凝脱浊效果与沉淀性能,且PAC/PDM质量复合配比越低,PDM特征粘度越高,脱浊效果与沉淀性能越好.     

高校宿舍甲醛污染健康风险评价

针对高校宿舍空间及人均面积占有量较小的特点,导致室内空气污染严重,尤其是新装修的宿舍,由装修所带来的污染不可忽视.本文以装修所带采的典型污染物甲醛为测评对象,分别测定了男女生宿舍室内甲醛含量在一天内的变化,利用SPSS软件分析得出甲醛浓度的变化规律,且女生宿舍甲醛浓度大约是男生宿舍的1.3倍,并对此给出了合理解释.利用EPA健康风险评价模型得出室内甲醛污染带来的致癌风险,最后提出了4项科学具体的预防措施,旨在提高人们对高校宿舍装修带来的污染的重视.     

焦化行业环境风险案例分析研究

焦化项目生产过程中涉及众多危险物质,存在着诸多环境风险隐患。本文主要从焦化行业特征污染物出发,以外排大气颗粒物及BaP这两种典型的行业特征污染物为例,研究山西某焦化技改项目生产事故中特征污染物的排放给区域带来的环境风险,并提出相关建议。     

丹江口水库水位抬高面临的挑战及其对策

移民与生态环境问题是丹江口水库水位抬高所面临的主要问题。移民问题是水位抬高首当其冲需要解决的难题,存在政策法规、移民资金、安置措施、脱贫致富等问题,需要以市场为导向,综合考虑诸多因素,制定可行的移民规划,确保移民的稳定和发展。生态环境问题是非常艰巨的问题,水土流失严重、污染源与污染总量日益增加、水质下降、支流库湾富营养化进程加剧等问题将困扰水库的运行与管理,后靠移民的生产生活也在一定程度上对生态环境产生影响;建议成立专门的监管机构,全方位开展水源地保护工作,确保水库水质安全和南水北调中线工程战略目标的实现。     

大学校园土壤中重金属污染研究

为研究大学校园土壤中重金属污染的状况,在西部某高校校园中选取10个采样点,分别采集了表层和下层土样,分析测定了土样中Cu,Zn,Pb,Cr四种重金属的含量。实验采用了微波消解、火焰原子吸收分光光度法对土样进行测定。结果表明待测校园土壤中重金属含量目前处于安全的范围,但大学,尤其是高等科研院校,应妥善处理科研试验过程中产生的污染物,为大学学生提供一个安全的大学校园环境。     

乳状液膜分离法预处理垃圾渗滤液氨氮的试验研究

用span-80表面活性剂制作的乳状液处理垃圾渗滤液中氨氮,考察了表面活性剂span-80用量、膜内相硫酸浓度、膜增强剂用量、油内比、乳水比、外相水pH值因素对氨氮去除率的影响。结果表明,在最佳反应条件下,用乳状液膜分离法预处理垃圾渗滤液中的氨氮,分离速度快,处理效果达到87%以上。     

Degradation of chlorpyrifos in laboratory soil and its impact on soil microbial functional diversity

Degradation of chlorpyrifos at different concentrations in soil and its impact on soil microbial functional diversity were investigated under laboratory conditions. The degradation half-lives of chlorpyrifos at levels of 4, 8, and 12 mg/kg in soil were calculated to be 14.3, 16.7, and 18.0 d, respectively. The Biolog study showed that average well color development (AWCD) in soils was significantly (P < 0.05) inhibited by chlorpyrifos within the first two weeks and thereafter recovered to the similar level as the control. A similar variation in the diversity indices (Simpson index 1/D and McIntosh index U) in chlorpyrifos-treated soils was observed, no significant difference in the Shannon-Wiener index H' was found in these soils. With increasing chlorpyrifos concentration, the half-lives of chlorpyrifos were significantly (P ≤ 0.05) extended and its inhibitory effects on soil microorganisms were aggravated. It is concluded that chlorpyrifos residues in soil had a temporary or short-term inhibitory effect on soil microbial functional diversity.     

Identification and characterization of the chromium（Ⅵ） responding protein from a newly isolated Ochrobactrum anthropi CTS-325

A Gram-negative, chromium(VI) tolerant and reductive strain CTS-325, isolated from a Chinese chromate plant, was identified as Ochrobactrum anthropi based on its biochemical properties and 16S rDNA sequence analysis. It was able to tolerate up to 10 mmol/L Cr(VI) and completely reduce 1 mmol/L Cr(VI) to Cr(III) within 48 h. When the strain CTS-325 was induced with Cr(VI), a protein increased significantly in the whole cell proteins. Liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis revealed that this protein was a superoxide dismutase (SOD) homology. The measured superoxide dismutase activity was 2694 U/mg after three steps of purification. The SOD catalyzes the dismutation of the superoxide anion (O₂^·−) into hydrogen peroxide and molecular oxygen. This protein is considered to be one of the most important anti-oxidative enzymes for O. anthropi as it allows the bacterium to survive high oxygen stress environments, such as the environment produced during the reduction process of Cr(VI).