基于OMI数据的新疆地区臭氧柱浓度研究

利用臭氧监测仪（OMI）卫星反演数据,对2005~2018年新疆地区大气臭氧柱浓度数据进行提取及分析,探讨其时空分布格局及影响因素.结果表明：在时间变化上,2005~2018年,新疆地区大气臭氧柱浓度整体呈现逐渐上升趋势.在空间分布上,臭氧柱浓度自北向南逐渐降低,高值区集中分布在阿尔泰、塔城北部以及昌吉北部等区域;低值区集中于和田、巴音郭楞蒙古自治州和喀什的南部大部分地区.在季节变化上,大体呈现出春夏季高于秋冬季,高值区在春夏季交替出现,冬季略高于秋季,但四季的臭氧柱浓度值呈现逐渐上升的趋势.稳定性分析表明：研究区域臭氧柱浓度整体呈现中部及南北部分散、东西部集聚的分布格局.自然因素中,气候因素、风场以及海拔均呈现显著正相关（P<0.01）;通过后向轨迹追踪发现,该区域西北和西部气流是臭氧外来的最主要输送路径,分别占总气流轨迹的78.59%、57.29%.人为因素中,臭氧柱浓度值与地区生产总值、煤炭消耗量、工业废气排放量及机动车保有量均表现出显著的正相关关系（P<0.05）.其中,挥发性有机物（VOC_s）主要来源于工业源,其次是交通源和居民源.总体来看,臭氧浓度的变化受到了诸多因素的综合影响,但气温、VOC_s的排放及吸收性气溶胶是大气臭氧浓度变化的主导因素.     

近14年西北地区甲醛柱浓度的时空变化研究

基于臭氧监测仪（OMI）卫星反演数据,对2005~2018年西北4省区域大气甲醛柱浓度数据进行提取及分析,探讨其时空变化特征及影响因素.结果表明：在时间变化上,14a甲醛柱浓度整体呈先上升后下降的波动变化趋势,夏秋季显著高于冬春季,且冬季均值略高于春季.在空间分布上,甲醛柱浓度自西向东、自北向南逐渐升高,高值区集中于陕西和甘肃东南部及青海西南部;低值区集中于宁夏、青海和甘肃的西北部;稳定性呈现出东部分散、西部集聚、差异显著的分布格局.影响甲醛柱浓度变化的因素包括自然和人为因素,自然因素中,甲醛柱浓度受地形影响显著,与风向、气温均呈现显著正相关;人为因素中,甲醛柱浓度与人口密度、地区生产总值、工业废气排放量及建筑房屋竣工面积均表现出正相关关系,与工业废气排放量的相关度最高.大气中甲醛分子与气溶胶粒子二者间呈显著正相关关系,这进一步说明甲醛浓度受到了诸多因素的综合影响,但气溶胶粒子、气温及工业废气的排放是主导因素.     

近12年华北五省区域对流层甲醛柱浓度时空变化及影响因素

利用臭氧监测仪(OMI)卫星反演的甲醛柱浓度产品,探讨了2005—2016年间华北五省区域对流层甲醛柱浓度的时空分布变化特征及相关的影响因子,结果表明:近12年对流层甲醛柱浓度整体呈现上升趋势,2005—2011年甲醛柱浓度呈逐渐升高趋势,最高增长达32.24×1013mole·cm~(-2),且高值区逐渐扩大.空间分布上高值区整体分布在北京、天津及周围区域,低值区分布在河北的北部、河南的南部和山东的东部区域;2012—2016年甲醛柱浓度波动较小,呈下降趋势.12年中,每年的2—4月份甲醛柱浓度出现最小值,6—8月份甲醛柱浓度出现最大值,而2005年2月份甲醛柱浓度值最小,2011年7月份甲醛柱浓度值最大.四季对流层甲醛浓度水平:夏季秋季春季冬季.风向会影响甲醛浓度的扩散方向,气温的增加导致甲醛柱浓度的升高.但12年间区域生产总值的提高、汽车保有量增加和农业秸秆焚烧是影响甲醛柱浓度增加的主导因素.     

基于OMI数据的四川盆地对流层甲醛时空分布特征

基于OMI卫星遥感反演的对流层甲醛柱浓度资料,对2005—2016年四川盆地对流层甲醛柱浓度的时空分布特征及其影响因素进行了分析.结果表明,12年间甲醛柱浓度年际变化总体呈上升趋势,年均增长率为1.17%.12年间甲醛柱浓度具有波动性,年均最低值和年均最高值分别出现于2005年和2012年.2005—2008年四川盆地甲醛柱浓度相对较低;2011年对流层甲醛柱浓度达到最大且高值区范围最大,2012年后浓度逐渐降低.四川盆地甲醛柱浓度季节变化表现为夏季春季秋季冬季.一年之中,月均甲醛柱浓度最小值基本出现在每年的11—12月,最大值则出现在6—8月.甲醛柱浓度空间分布的高值区主要分布在盆地内西南部的成都平原地区,低值区则多处于人为源排放较低的重庆东北部山区.能源消耗、生产总值及机动车保有量与对流层甲醛柱浓度具有显著的正相关关系.工业源、居民源和交通源排放对甲醛柱浓度具有重要贡献.四川盆地独特的地形及区域内风场对甲醛的扩散也有重要影响.     

昆明市臭氧污染特征及与气象因子关系初步研究

对昆明市2014—2018年空气质量和臭氧(O3)污染特征进行了分析,并结合臭氧污染观测资料和气象条件,对昆明市臭氧浓度与气象因子相关性进行了初步研究。结果表明:昆明市空气质量总体逐渐变好,臭氧浓度整体呈上升趋势,春季和夏季臭氧污染比较明显;臭氧浓度春季高,秋冬季低,高值主要集中在3—5月;臭氧污染主要出现在3—8月,7月最高;臭氧浓度与太阳辐射、气温、大气低层温度垂直分布、风速等总体呈正相关,与气压、相对湿度总体呈负相关。     

辽宁省近12年对流层甲醛柱浓度时空变化及其影响因素

基于OMI遥感反演的对流层甲醛柱浓度资料,研究了辽宁省2005—2016年对流层甲醛柱浓度的时空分布特征,并分析了对流层甲醛柱浓度的主要影响因素.结果表明:近12年辽宁省对流层甲醛柱浓度整体上波动较大,2005—2013年逐渐增大,平均增速为0.74×1015molec·cm-2,空间分布上整体表现为低值区主要分布在辽西山地丘陵地区,高值区分布在沈阳以东大部分地区,浓度在12×1015~13×1015molec·cm-2之间;2005—2008年辽宁省甲醛污染相对较轻,对流层甲醛柱浓度整体多在3级水平以下;2009—2013年之间,对流层甲醛柱浓度的3级分布区域逐渐缩小,4级分布区域不断扩大,并在2010年出现5级水平污染区域且于2013年达到最大.春季各个区域对流层甲醛柱浓度相对于其它季节较低,夏季各个地区对流层甲醛柱浓度值整体上高于其它季节,以4级及5级水平污染为主,秋、冬季各个区域的对流层甲醛柱浓度值分布居于春、夏两季之间.辽宁省对流层甲醛柱浓度的月变化特征大致符合正弦曲线分布特征,即对流层甲醛柱浓度自1月不断上升,于6月达到峰值后又不断下降.能源消耗及工业生产与大气中甲醛的浓度的变化息息相关,人口数量及生产总值与对流层甲醛柱浓度也具有显著的正相关关系.高温利于甲醛的扩散和挥发,辽宁省独特的地形地理位置对甲醛的扩散与传播产生影响.     

京津冀对流层甲醛的时空演变特征及其影响因素

依据2009—2016年OMI卫星反演的逐日数据,结合遥感图像处理技术和克里金插值法,对京津冀地区对流层甲醛柱浓度的时空特征及影响因素进行了分析.结果发现,2009—2016年8年间京津冀地区甲醛柱浓度年际变化总体呈上升趋势,年均增长率为1.01%,最大增长率出现于2009—2010年,为12.91%.8年间,甲醛柱浓度值具有波动性,最低值和最高值分别出现于2009年和2013年.研究区甲醛柱浓度季节变化表现为夏季值秋季值冬季值春季值,甲醛柱浓度月均值在每年的6月达到最高.甲醛柱浓度空间分布的低值区大多处于地势较高的京津冀地区西北部,高值区主要分布在京津冀地区南部平原.甲醛柱浓度变化不仅与自然因素的温度呈显著正相关,与气压呈显著负相关,还与社会经济因素中的煤炭消耗量、原油消耗量及工业增加值等呈正相关.京津冀地区甲醛柱浓度时空特征总体受当地自然和社会经济因素的综合影响.     

东亚地区大气整层臭氧浓度的时空变化

从TOMS臭氧全球网格资料截取主要包含中国大陆的东亚地区 (6 9 375°E— 1 39 375°E ;1 4 5°N— 5 4 5°N)的数据 ,分析大气整层臭氧浓度的变化特征 .结果表明 ,区域多年平均臭氧浓度约为 30 7DU(多卜森单位 :DobsonUnit) ;一年中 ,平均臭氧浓度有明显的季节变化 ,春季 (3月 )达最大值 ,秋季 (1 0月 )最小 ,变化幅度约 5 0DU .区域内臭氧浓度具有很强的空间 (纬向 )变化 ,低纬度地区臭氧浓度低 ,较高纬度地区臭氧浓度高 .各地臭氧浓度变化的概率分布基本为单峰型 ,低纬度地区分布较窄而高纬度地区宽 .从 1 978至 1 994年的十多年中 ,区域平均浓度呈明显的下降趋势 ,下降幅度约 1 0DU .对应于此 ,区域内各等级的臭氧浓度值以大致均匀的速率变化 ,低值的出现概率增加 ,而高值的出现概率减小 .     

近三年中国甲醛时空分布特征及影响因素分析

近年来,研究大气污染物的时空分布特征及影响因素分析已成为环境科学领域研究的热点问题.本文基于OMI甲醛垂直柱浓度数据产品,结合各省市气象、植被、人类活动等数据,对全国2015—2017年甲醛柱浓度时空分布特征及影响因素进行了研究.结果表明,全国甲醛柱浓度分布极不均衡,整体呈现自东南沿海向西北递减的趋势,此外在新疆与西藏的小部分地区存在高值区域.3年来全国甲醛柱浓度为整体上升,且变化率在-1.02～1.46之间,其中全国81%地区呈上升趋势,19%地区呈下降趋势.全国甲醛柱浓度季节性变化规律表现为夏季春季秋季冬季.甲醛柱浓度时空分布受气象因素影响,整体上与气温、降水呈正相关,但部分地区降水对甲醛有消减作用;甲醛柱浓度也与植被量呈正相关,如植被丰富的西藏地区及我国东南部,植被对甲醛柱浓度的影响显著.全国大多数省份甲醛柱量与地区生产总值、汽车保有量呈显著正相关,人类足迹分布模式与甲醛柱浓度空间分布的一致性较高,指示在城市发达地区,人类活动和经济发展、汽车尾气是导致甲醛柱浓度增高的主要原因.     

广东省对流层HCHO柱浓度时空动态分布及影响分析

本文基于OMI卫星遥感反演数据,结合趋势分析、残差分析及Hurst指数,对广东省2009—2018年对流层甲醛柱浓度时空分布特征进行了分析,并结合NDVI、工业总产值、汽车保有量等因素,进一步探究了广东省自然和社会要素结构变化与甲醛柱浓度变化的关系.结果表明,广东省近10年的甲醛柱浓度均值为15.365×10¹⁵ molec·cm^-2,处于全国前列水平,且近10年来年际间浓度变化波动较大.研究发现,甲醛柱浓度四季变化较为明显,春季高、夏季低,且季节性增长较为明显,其中,春、秋、冬三季平均增幅达到15.5%;月际变化与季节变化较为一致,受自然因素影响较为强烈.空间变化主要表现为甲醛柱浓度值由西南往东北递增,其中,高值区分布在广东省的中部和东北部地区,低值区分布在南部和西南部地区;残差研究发现,人类活动依然是影响广东省甲醛分布的主要因素,占87.64%,影响因素主要包括规模以上企业数量、工业废气排放等经济发展要素,并与能源消耗总量及工业生产总值的增加密切相关.自然因素如气温、降水、NDVI对甲醛的生成和分布有促进作用.通过Hurst指数可以发现,未来广东省甲醛柱浓度整体呈下降的趋势,但部分地区如东莞、深圳市等地未来有增加的趋势.     

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.     

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.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.     

Simultaneous removal of ammonium and phosphate by zeolite synthesized from coal fly ash as influenced by acid treatment

Zeolite synthesized from fly ash （ZFA） without modification is not efficient for the purification of NH4＋ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 （≥0.9 mol/L） resulted in a limited maximum phosphate immobilization capacity （PIC）. It was concluded that through a previous mild acid treatment （e.g. 0.01 mol/L of H2SO4）, ZFA can be used in the simultaneous removal of NH4＋ and P at low concentrations simulating real effluent.