新疆四城市大气质量及污染物变化趋势对比分析研究

对新疆四城市三种主要污染物(SO2、NO2、PM10)的年均污染水平状况、大气空气质量等级天数以及主要污染物天数进行对比分析,探讨四城市环境质量状况.通过收集2009年-2015年四城市三种污染物的质量监测数据,使用统计描述、卡方分析等对四个城市的污染特征进行评价.得到2009年-2015年四城市优良天数由高到低为克拉玛依市>伊宁市>乌鲁木齐市>喀什市.证明了2009-2015年四城市环境质量状况有所改善;大气环境中污染物SO2、NO2总体上呈下降趋势,PM10呈上升趋势.     

"十二五"期间义乌市环境空气质量及影响因素分析研究

利用环境空气质量监测数据,对义乌市2011年-2015年环境空气质量变化趋势及影响因素进行了分析.结果表明,影响义乌空气质量的主要污染物为:PM2.5、PM10、NO2、O3,且大气污染呈现为扬尘和机动车尾气并存的混合型污染.尽管PM2.5、PM10和SO2总体均呈现下降趋势,尤其是SO2下降显著,但细颗粒物污染仍然突出,NO2不降反升等问题都值得关注.这可能与义乌市城市化进程进一步加快、能源结构亟待优化以及机动车保有量不断攀升等因素有关.     

泸州市城区2004-2009年空气质量时空变化

为了掌握泸州市城区近年空气质量时空变化,对泸州市城区2004-2009年空气质量监测数据进行系统分析。结果表明,近年来泸州市城区空气质量总体良好,平均空气污染指数为80,空气质量优良率在72.33%以上。空气质量有逐步好转的趋势,SO2和PM10年平均浓度明显下降,NO2略有上升。污染物浓度时空分布不均匀,SO2与PM10夏季浓度较低,冬季较高,NO2浓度季节性变化不明显;兰田宪桥、小市上码头污染物浓度总体上高于忠山环监站。     

重庆市北碚区SO2、NO2变化趋势及影响因素分析研究

采用2006年-2013年大气自动监测站实时发布的数据,研究分析了SO2与NO2的时间变化规律以及气象影响因素的相关性分析.结果表明,空气质量年均值均低于GB 3095-2012中的Ⅱ级标准;SO2浓度年均值2013年较2006年低45.8％,下降显著,NO2浓度年均值2013年较2006年低5.9％,下降不明显;春冬季空气质量差、夏秋季空气质量好;SO2 、NO2月均值峰值分别出现在2007年11月和2009年3月;相对于SO2浓度更易受到近地面气象因子平均温度的影响而积累或扩散,而NO2浓度更易受到近地面气象因子平均相对湿度的影响而积累或扩散.     

西安市空气质量的模糊综合评价研究

模糊综合评价是以模糊数学为基础,应用模糊关系集合,对不容易定量的因素进行量化,从而进行的一种综合评价.采用模糊数学的基本原理,以西安市2012年空气质量监测的SO2 NO2和PM10三种污染物的数据为材料,对西安市每个监测点一段时期以来的空气质量进行综合评价.结合综合评价的结果和统计2012年每个月的空气质量状况,得到西安市各个区域空气质量的时间和空间分布特征.最后提出提高西安市环境空气质量的合理建议.     

济南市秋季大气颗粒物中水溶性离子的粒径分布研究

为了解济南市大气颗粒物的粒径分布特征,于2009年10月利用多级撞击式颗粒物采样器(MOUDI)进行了大气颗粒物采集,采用离子色谱仪分析了其中水溶性离子浓度.结果表明,SO42-、NO3-、NH4+和Ca2+是主要的水溶性离子,浓度总和约占总水溶性离子浓度的92%.SO42-、NO3-、NH4+、K+和Cl-浓度随时间变化较为显著,浓度变化主要原因是受风速以及气流来源方向的影响.SO42-和NH4+主要集中在细粒子中,其浓度呈单模态分布,随着颗粒物中含量的升高其峰值从0.32~0.56 μm粒径段逐渐移动到1~1.8 μm粒径段.NO3-浓度呈双峰分布,细粒子中的NO3-随着浓度的升高峰值从0.56~1μm粒径段移动到1~1.8μm粒径段,粗粒子中的峰值出现在3.2~5.6μm粒径段. NH4+可以完全中和细粒子中的SO42-和NO3-,在细粒子中主要以(NH4)2SO4和NH4NO3的形式存在.     

眉山市城区环境空气质量及变化趋势分析

根据眉山市2006—2012年空气质量数据,采用综合污染指数法对SO2、NO2、PM10进行评价。结果表明:各污染物季节变化明显,冬季污染最严重;7年年际变化中,SO2浓度先上升后下降,NO2浓度总体呈上升趋势,PM10浓度明显下降;2012年全市主要污染物污染负荷系数从大到小排列顺序为:PM10(0.39)SO2(0.32)NO2(0.29);综合污染指数表明眉山市空气质量属于轻污染。     

西安市2013年空气质量状况分析

本文收集西安市2013年环境监测站发布的空气质量指数（AQI）及环境空气状况与监测月报资料,对空气质量等级、AQI变化情况、主要污染物浓度变化趋势及采暖期和非采暖期浓度比较进行分析.研究结果表明：西安市2013空气质量二级以上的达标率为37.8％,年均AQI值为151,SO2、NO2、PM10和PM2.5的月监测浓度变化趋势无显著意义,采暖期平均浓度均显著高于非采暖期平均浓度,PM2.5采暖期均值是非采暖期均值的3.09倍.由此可见控制SO2、NO2、PM10和PM2.5的排放是改善西安市空气质量的重点工作.     

榆林市城区环境空气质量污染特征及原因分析

根据榆林城区环境空气质量监测数据,对2001～2010年间榆林城区空气质量污染特征和主要空气污染物的变化规律进行了分析。结果表明:2001～2010年间,榆林市城区的SO2、NO2和颗粒物污染总体呈下降趋势;2007～2010年间,SO2和PM10的季节性污染特征较明显,SO2浓度高值主要集中在冬季采暖期,PM10浓度高值主要集中在春季沙尘常发期的3～6月,NO2浓度全年均无超标,季节性变化较稳定。     

渝北区环境空气质量现状及污染原因分析

本文采用综合污染指数法和空气质量指数法对2014年重庆市渝北区的主要空气污染物(SO2、PM10、NO2、O3、CO、PM2.5)的现状监测值进行了评价。结果表明:对照环境空气质量标准,2014年城区内SO2、NO2均符合国家空气质量二级标准,PM10、PM2.5测定值均超标。污染物浓度时空分布不均匀,冬春季浓度较夏秋季高,出现明显的季节特征;空间分布上,两路空气质量优于空港。2014年渝北区环境空气中大部分污染物浓度均低于2013年和主城平均浓度,环境空气质量综合污染指数呈现下降趋势。2014年渝北区空气质量优良天数255天,高于2013年和主城优良天数,影响渝北区空气质量的首要污染物为PM2.5,其次为PM10、O3-8h、NO2。渝北区的环境空气污染主要受城市建设、产业结构、气象条件、交通尾气的影响。     

Evaluation of phytoextracting cadmium and lead by sunflower, ricinus, alfalfa and mustard in hydroponic culture

Soil contaminated with heavy metals cadmium(Cd)and lead(Pb)is hard to be remediated.Phytoremediation may be a feasible method to remove toxic metals from soil,but there are few suitable plants which can hyperaccumulate metals.In this study,Cd and Pb accumulation by four plants including sunflower(Helianthus annuus L.),mustard(Brassica juncea L.),alfalfa(Medicago sativa L.), ricinus(Ricinus communis L.)in hydroponic cultures was compared.Results showed that these plants could phytocxtract heavy metals, the ability of accumulation differed with species,concentrations and categories of heavy metals.Values of BCF(bioconcentration factor)and TF(translocation factor)indicated that four species had dissimilar abilities of phytoextraction and transportation of heavy metals.Changes on the biomass of plants,pH and Eh at different treatments revealed that these four plants had distinct responses to Cd and Pb in cultures.Measurements should be taken to improve the phytoremediation of sites contaminated with heavy metals,such as pH and Eh regulations,and so forth.     

Oxidation of As(Ⅲ) by potassium permanganate

The oxidation of As(Ⅲ) with potassium permanganate was studied under conditions including pH, initial As(Ⅲ) concentration and dosage of Mn(Ⅶ). The results have shown that potassium permanganate was an effective agent for oxidizing of As(Ⅲ) in a wide pH range. The pH value of tested water was not a significant factor affecting the oxidation of As(Ⅲ) by Mn(Ⅶ). Although theoretical redox analyses suggest that Mn(Ⅶ) should have better performance in oxidization of As(Ⅲ) within lower pH ranges, the experimental results show that the oxidation efficiencies of As(Ⅲ) under basic and acidic conditions were similar, which may be due to the adsorption of As(Ⅲ) on the Mn(OH)2 and MnO2 resulting from the oxidation of As(Ⅲ).     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Chlorobenzenes in waterweeds from the Xijiang River （Guangdong section） of the Pearl River

The Xijiang River is the major source of water for about 4.5 millions of urban population and 28.7 millions of rural population. The water quality is very important for the health of the rural population. The concentration and distribution of chlorobenzenes (CBs) in both water and waterweeds collected from 4 stations in the Xijiang River (Gangdong section) of the Pearl River in April and November were determined. The result showed that nearly every congener of CBs was detected. The total contents of CBs (∑CBs) in the river water ranged from 111.1 to 360.0 ng/L in April and from 151.9 to 481.7 ng/L in November, respectively. The pollution level of CBs in the water in April was higher than that in November. The contents of ∑ CBs in waterweeds ranged from 13.53×102 μg/g to 38.27×102μg/g dry weight (dw). There was no significant difference between April and November in waterweeds. The distribution of CBs in roots, caulis, and leaves of Vallisneria spiralis L. showed different patterns. The leaves mainly contained low-molecular-weight CBs(DCBs), whereas the roots accumulated more PCBs and HCBs. The average lgBCFlip (bioconcentration factor) of CBs ranged from 0.64 to 3.57 in the waterweeds. The spatial distribution character of CBs in the Xijiang River was: Fengkai County ＜ Yunan County ＜Yun'an County ＜ Gaoyao County according to the ∑CBs, and the pollution deteriorated from the upstream to the downstream of the Xijiang River. Further analysis demonstrated that the discharge of waste containing CBs may be the main source of CBs pollution in the Xijiang River.     

Degradation of 2,4-dichlorophenol with a novel TiO2/Ti-Fe-graphite felt photoelectrocatalytic oxidation process

Degradation of 2,4-dichlorophenol(2,4-DCP)was studied in a novel three-electrode photoelectrocatalytic(PEC)integrative oxidation process,and the factors influencing the degradation rate,such as applied current,flow speed of O_2,pH,adscititious voltage and initial 2,4-DCP concentration were investigated and optimized.H_2O_2 was produced nearby cathode and Fe~(2 )continuously generated from Fe anode in solution when current and O_2 were applied,so,main reactions,H_2O_2-assisted TiO_2 PEC oxidation and E-Fenton reaction,occurred during degradation of 2,4-DCP in this integrative system.The degradation ratio of 2,4-DCP was 93% in this integrative oxidation process,while it was only 31% in E-Fenton process and 46% in H_2O_2-assisted TiO_2 PEC process.So,it revealed that the degradation of 2,4-DCP was improved greatly by photoelectrical cooperation effect.By the investigation of pH,it showed that this integrative process could work well in a wide pH range from pH 3 to pH 9.     

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

The influence of coexisting copper (Cu) ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied.Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time,the analysis of the extracts from the soil was carried out using gas chromatography (GC).The photodegradation of pyrethroids in water system was conducted under UV irradiation.The effect of Cu~(2 ) on the pesticides degradation was measured with half life (t_(0.5)) of degradation.It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed.But Cu~(2 ) could accelerate photodegradation of the pyrethroids in water.The t_(0.5) for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil.As for photodegradation,t_(0.5) for cyhalothrin reduced from 173.3 to 115.5 rain and for cypermethrin from 115.5 to 99.0 min.The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms.However, it had catalyst tendency for photodegradation in water system.The difference for the degradation efficiency of pyrethroid isomers in soil was also observed.Copper could obviously accelerate the degradation of some special isomers.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.