泾河支流地表水地下水的水化学特征及其控制因素

为研究泾河支流(黑河流域)的水化学特征及其控制因素,2014~2015年先后采集枯水期及汛期地表水和地下水的水样242个,综合运用Piper三线图、相关性分析和Gibbs图等方法,分析了黑河流域水化学特征,并探讨了黑河流域的水化学演化规律.结果表明,研究区水体均呈弱碱性,2014年枯水期地表水和地下水阳离子以Na+为主,分别约占阳离子总量的56%和58%;阴离子以SO_4~(2-)为主,分别约占地表水和地下水阴离子总量的33%和39%;其它3个时期主要地表水和地下水组成阴阳离子均以HCO_3~-和Na~+为主,约占阴离子和阳离子总量的44%~46%和42%~56%.枯水期地表水TDS在上中游波动较大,汛期地表水和地下水的TDS由上游到下游沿河道逐渐增加.由枯水期到汛期,地表水的水化学类型由Na-Mg-Cl-SO4型转变为Ca-Mg-HCO3型,地下水由Mg-Cl-SO_4型转变为Ca-Na-HCO_3型.水化学样品点大部分分布在Gibbs图左中上部,说明流域水化学离子形成主要受岩石风化和蒸发-浓缩作用的影响,而人类活动对水化学的影响在枯水期较汛期更显著.     

基于水化学和氢氧同位素的东宫河流域不同水体转化关系研究

为明晰秦皇岛东宫河流域水环境特征,以该流域大气降水、地下水及地表水为研究对象,通过对水化学和氢氧稳定同位素样品测试及特征分析,揭示其时空变化特征及大气降水、地下水和地表水的相互转化关系.结果表明:①东宫河流域地下水（第四系孔隙水、岩溶水、裂隙水）和地表水（河水、泉水）的水化学类型,枯水期较丰水期丰富.丰水期水化学类型主要以HCO₃-Ca型、HCO₃·SO₄-Ca型和HCO₃-Ca·Mg型为主;枯水期水化学类型以HCO₃-Ca型、HCO₃-Ca·Mg型、HCO₃·SO₄-Ca型、HCO₃·SO₄-Ca·Mg型为主.②研究区第四系孔隙水和泉水的离子含量变化受季节影响较大,枯水期离子含量变化较丰水期显著;岩溶水和裂隙水各离子含量变幅较小,基本趋于稳定.岩溶含水层和裂隙含水层中富含石膏,为SO₄2-的主要来源;Na+和Cl-主要来源于易溶解盐NaCl,Ca2+和Mg2+主要来源于方解石的风化溶解.③东宫河流域地下水、地表水及大气降水之间存在密切的水力联系,针对氢氧同位素的组成分析表明,大气降水为地下水和河水的主要来源;不同泉水补给来源存在差异性,泉水主要接受岩溶水补给,同时也受蒸发作用影响;第四系孔隙水接受大气降水和河水的双重补给;裂隙水主要接受山区降水径流补给.研究显示,东宫河流域不同水体中离子含量受降雨量、温度和地质背景等影响,不同水体间联系密切,相互补给排泄.      

南小河沟流域地表水和地下水的稳定同位素和水化学特征及其指示意义

南小河沟流域为典型的黄土高原沟壑区,本文分析了该流域地表水和地下水的氢氧稳定同位素和水化学特征,揭示了地表水与地下水之间的相互关系.结果表明,大气降水的δD和δ~(18)O值呈现春夏高,秋冬低的季节变化特征.水库水的δD和δ~(18)O值的季节性变化规律呈现夏秋高、冬春低的特征.地下水的δD和δ~(18)O值季节性变化规律相对不显著.流域内地表水和地下水水化学类型主要为Na·Mg-HCO_3型.地表水和地下水电导率的季节性变化规律均呈现冬季高、夏季低的特点.当地大气降水和深层地下水可能是南小河沟流域内地表水(水库水、沟道水)和泉水的主要补给来源.流域内的常流泉可能主要由深层地下水补给,而季节泉,例如,董庄沟和杨家沟的源头泉则可能是由深层地下水和当地大气降水共同补给.     

丹江流域山区地表水-地下水水化学特征及其影响因素

丹江流域是南水北调中线工程重要水源涵养区,深入研究丹江流域水化学特征及其影响因素,对区域水资源保护及合理利用具有重要意义.通过对丹江流域水样采集与分析,综合运用描述性统计、Piper三线图、Gibbs图、离子比例系数法及氢氧同位素的方法,分析丹江流域水化学特征及其影响因素.结果表明,丹江流域水体整体呈弱碱性,主要水化学类型为HCO3-Ca型,中游离子质量浓度及水化学类型变化频繁.流域水体均受大气降水补给,地表水受蒸发作用影响明显,水化学组分受岩石风化溶解、离子交换和人类活动共同影响. Ca2+和Mg2+源于方解石、白云石及石膏等碳酸盐和硫酸盐矿物溶解,农业活动是水中硝酸盐的主要来源.地表水与地下水频繁转化和支流汇入影响是丹江干流空间分布特征差异化的主要原因.     

店埠河流域地表水-地下水水化学特征及其成因分析

巢湖是我国水污染防治的重点水体,但近年来一直处于较高的富营养化水平.以巢湖二级支流店埠河流域内的地表水和地下水为研究对象,测试不同水体水化学组成和氢氧同位素值,综合运用数理统计、Piper三线图、Gibbs图和离子比值等方法,分析其季节性和空间变化特征,探讨地表水和地下水的水化学特征和形成机制.结果表明,①大气降水是店埠河流域地表水和地下水的主要补给来源,地表水的蒸发分馏效应比地下水更显著.不同时期,地表水比地下水更富集氢氧稳定同位素.地表水和地下水中氢氧稳定同位素均呈季节性变化特征,丰水期相对富集,枯水期相对贫化.②店埠河流域地表水和地下水均为弱碱性水,地表水中各离子浓度明显小于地下水,地表水中阳离子以Ca²⁺和Na⁺为主,地下水中阳离子以Ca²⁺为主,水体中的优势阴离子均为HCO₃^-.地表水的水化学类型以HCO₃·Cl-Na·Ca型水为主,地下水以HCO₃-Na·Ca型水为主.③地表水和地下水主要水化学指标浓度具有一定的时空差异性.从丰水期到枯水期,地表水中TDS、K⁺、Na⁺、Ca²⁺、Mg²⁺、Cl^-和SO₄^2-浓度整体呈现上升趋势.地下水中Na⁺、Ca²⁺和Mg²⁺浓度整体变化不大,略有增加趋势,Cl^-、SO₄^2-和NO₃^-浓度整体呈上升趋势.从上游到下游,地表水中主要水化学指标浓度呈现先减小后增大的趋势,NO₃^-浓度增幅最大.地下水在径流方向上主要水化学指标浓度整体变化不大,但呈现出排泄区大于补给区的规律.④水体水化学特征的形成主要受水-岩作用控制,同时还受到人为因素影响.水-岩作用主要为硅酸盐岩、盐岩和碳酸盐岩等矿物的风化溶解.污水处理厂污水、生活污水和粪肥等污染物已明显改变了局部水体的水化学特征.⑤与2016年相比,地表水中的NO₃^-浓度已有不同程度地减少,当地政府进行的氮污染控制工作已取得一定成效,但仍需在店埠河下游、部分支流（定光河和马桥河）和部分居民点加强对污水及粪肥的污染防控.     

疏勒河上游地表水水化学主离子特征及其控制因素

在系统收集了疏勒河流域上游河水、地下水、降水和冰雪融水水样的基础上,综合运用描述性统计、Gibbs图和Piper阴阳离子三角图等方法,对疏勒河上游地表水中主离子组成特征及其控制因素进行了分析.结果表明,流域内不同水体(大气降水、河水和地下水)之间的主离子组成以及水化学类型差异显著.河水TDS的变化范围为51.7~432.3 mg·L-1,平均值为177.7 mg·L-1;河水中阳离子Ca2+、Mg2+的百分比为45%和31%,优势阴离子为HCO-3,占阴离子总量的75%,河水的水化学类型主要为HCO-3-Ca2+-Mg2+型;河水中主离子浓度值介于大气降水和地下水之间,并且十分接近地下水浓度,说明地表水同时受大气降水和地下水补给并主要依靠地下水补给;地表水样品的水化学组成落在Gibbs分布模型的中翼偏左端,表明研究区的水化学离子组成受到岩石风化作用和蒸发结晶作用的共同影响,且岩石风化作用对水化学离子组成的影响更加显著.     

乌梁素海流域水文地球化学演化及水盐运移

乌梁素海是深受国际社会关注的湿地生态系统保护区。该文以乌梁素海-地下水系统为研究对象,利用数理统计、水化学类型分析等方法探究地下水化学特征及演变规律。基于对区域水文地质资料收集、现场勘测、水样采集分析的基础上,揭示了乌梁素海流域地下水补径排特征,地表水和地下水的水力联系,进而确定出地下水对乌梁素海水分及盐分的补给量,定量分析了地下水补给对乌梁素海的影响。结果表明:(1)地下水从补给区到排泄区,TDS逐渐增加,水化学类型由重碳酸型到硫酸型再到盐酸型;(2)潜水每年约向湖泊补给2 398.7万m~3,76 785.5 t盐分;承压水每年约向乌梁素海补给889.1万m~3,15 895.4 t盐分。(3)地下水对乌梁素海补给量约占湖泊蓄水量11.0%～13.2%,盐量补给约占湖水含盐量的23.6%～28.3%。近年来开展的生态补水工程,初步抑制了乌梁素海"咸化",基本维持了湿地生态系统稳定。     

典型西北山地-绿洲系统不同水体水化学特征及其水力关系分析

开都河流域是西北内陆区典型的山地绿洲系统,其水化学信息对了解区域水文过程和优化水资源配置具有重要意义.基于2020年内不同季节山区、绿洲区多种水体样品的采集及测试,分析了该区域水化学特征及其水力联系.结果表明：(1)研究区水体整体呈微碱性,pH和TDS值呈现绿洲区高、山区低的分布特征;HCO^-₃和Ca²⁺为主要的阴阳离子,区域水化学类型多为HCO^-₃-Ca²⁺型,绿洲区地下水水化学类型较之山区更复杂;区域水化学特征受岩石风化和人类活动影响较为明显.(2)河水δ¹⁸O和δD值呈现夏季贫化、春季富集的季节变化特征,而地下水为冬春贫化,秋季富集;降水和冰川水年内变化不显著;河水及地下水的δ¹⁸O和δD值则表现为绿洲区富集、山区贫化的空间分布特征.(3)研究区地表水和地下水的相互关系密切,且在夏季转化频繁;绿洲区地表水与地下水的转化特征呈显著的时空差异性.研究结果对于我国西北内陆区水资源的优化配置具有重要意义.     

西苕溪流域地表水与地下水相互作用特征!

为探寻西苕溪地表、地下水体的来源和补排关系,对西苕溪流域丰水期和平水期的地表、地下水进行了氢氧同位素(δD和δ18O)组成分析,并结合水体的水化学参数,推断其来源和补排关系。结果表明:西苕溪流域地表、地下水体主要接受降雨补给,在上游山区中的泉水运移过程较为缓慢,上游地表水与地下水补排关系不明显;中游丘陵地区地表、地下水体相互联系紧密,具体补排关系为3号、4号、6号样点处地表水接受地下水补给,其余样点处为地表水补给地下水;下游农田密集区地下水接受河水补给较少。     

柳林泉域岩溶地下水区域演化规律及控制因素

柳林泉是山西省著名的十大岩溶大泉之一,丰富的岩溶地下水资源对吕梁地区经济社会发展具有支撑作用,开展岩溶地下水化学演化规律及控制因素研究对于流域水资源可持续利用意义重大.本研究对补给区、径流区、排泄区、深埋区的29个岩溶地下水主要离子组分进行测试分析.结果表明,水温、Na~+、Ca~(2+)、Mg~(2+)、Cl~-、HCO_3~-、SO_4~(2-)质量浓度从补给区、到径流区、到排泄区、再到深埋区,随着径流途径增加不断升高. K~+、Na~+、Cl~-主要来源于盐岩的溶解;而Ca~(2+)、Mg~(2+)、HCO_3~-、SO_4~(2-)主要来源于方解石、白云石和石膏的溶解.受控于盐岩、石膏的不断溶解,Na~+、C~l-和SO_4~(2-)质量浓度增加幅度大,最大值分别为最小值的50、80和32倍;受去白云化作用的影响,Ca~(2+)、HCO3-质量浓度变化不大,最大值仅为最小值的2～3倍.在补给区、径流区,Na~+、Cl~-质量浓度较低,Ca~(2+)和Mg~(2+)、HCO_3~-为主要阴阳子,但在排泄区和深埋区,Cl~-、Na~+明显超过了HCO_3~-、Ca~(2+)和Mg~(2+),成为最主要的阴阳离子;水化学类型由HCO_3-Ca·Mg型转化为HCO_3·SO_4-Ca·Mg型和HCO_3·SO_4-Ca·Na·Mg型,最终演变为Cl·HCO_3-Na·Ca、Cl·HCO_3-Na型和Cl-Na·Ca型.     

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.     

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.     

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.