首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
云南寻定几种农作物籽粒中重金属的比较研究   总被引:6,自引:0,他引:6  
通过对四种农作物(玉米、小麦、水箱、蚕豆)籽粒中八种重金属元素(Cu、Zn、Pb、Cd、Cr、Ni、As、Hg)的调查研究。结果表明,四种农作物籽粒中重金属元素量与土壤重金属含量呈正相关,籽粒中重金属的吸收系数大致为Cd〉Zn〉Cu〈Pb,玉米籽粒Cd〈Zn、Cu,可能由于元素间的交互作用,Cu、Zn、Pb、Cd含量均处于较高水平,由于不同农作物和物的生物学特性之间的差异,Cr,Ni、As、Hg在  相似文献   

2.
湄洲湾生物体内重金属含量及其评价   总被引:25,自引:3,他引:25  
以湿法消化和火焰原子吸收分光光度计测定了福建湄洲湾海域5种海洋生物体内Cu,Pb,Zn,Cd,Ni,Fe,Mn,Co的含量,并计算了生物对重金属的富集系数。结果表明:各种生物体内重金属含量Fe,Mn,Cu,Zn>Pb,Cd,Ni,Co。对多数其含量大小趋势为:双壳类软组织>海带>虾、鱼肌肉。牡晟对Cu,Zn,Cd的富集系数比其它生物高得多,湄洲湾生物体内重金属含量与国内外某些海域相近,远低于海洋生  相似文献   

3.
煤矸石模拟淋溶水重金属污染的研究   总被引:3,自引:0,他引:3  
通过对新旧煤矸石模拟淋溶水中重金属污染的研究认为:煤矸石淋溶水中重金属含量顺序为As〉Cr〉Pb〉Hg〉Cd;新旧矸石淋溶水中重金属的含量差别不大;汶南矿煤矸石淋溶水中As的含量明显的高于其它煤矿,不同煤矿矸石淋溶水中Pb、Cr、Hg和Cd含量无大的差别;淋溶水中Hg的含量随淋溶时间增加有一定的增加,淋溶时间长短对Pb、Cr、Cd和As含量无明显的影响。  相似文献   

4.
辽东湾双台子河海区动物体内污染物含量及时空分布   总被引:8,自引:2,他引:8  
1997年11月对辽东湾双台子河海区部分鱼类、贝类及甲壳动物体内的Hg、Cd、Pb、As、Cu、Zn和油的含量进行了调查,并对这些污染物的时空分布趋势进行了分析。结果表明:狼虾虎鱼体内的污染物的浓度分别为0.008(Hg)、0.88(Cd)、0.17(pb)、1.77(As)、0.25(Cu)、47.3(Zn)和8.36(油);贝在体内污染物的浓度分别为0.003-0.033(Hg)、1.16-1  相似文献   

5.
煤中部分潜在毒害微量元素在表生条件下的化学活动性   总被引:29,自引:2,他引:29  
利用连续化学浸取实验方法,对采自贵州省二叠经龙潭组的32个煤样中的10种潜在毒害微量元素化学的活动性进行了研究,结果表明:煤中Hg、As、Se、Cd等元素具有极强的化学活动性,其中平均83.8%的Hg、93.5%的As、80.3%的Se.63.3%的C在.1%的Cu的86.8%的Pb可以被带出煤中而进入表生环境;煤中Zn的化学活动性次之,只有平均46.6%的Zn可能迁移进行环境中;Tl、Cr、Ni  相似文献   

6.
滇池,洱海水及沉积物中重金属元素的行为   总被引:9,自引:0,他引:9  
洱海水中重金属元素的含量不同,平均值以10^-9计算:Cu1.6,Pb0.59,Zn9.8,Cd0.009,Cr0.24,水质较好;沉积物中每一样品同一元素的含量一般均趋于平均值,以10^-6计算:Cu111,Pb60,Zn127,Cd0.591,Cr130。因此,洱海至今仍是一个较清洁的湖泊。滇池水质较差,内草海段水中重金属元素含量明显上升,以10^-9计算:Cu5.8,Pb0.55,Zn32,  相似文献   

7.
上海潮滩表层沉积物重金属的分布特征   总被引:9,自引:0,他引:9  
1998年7月、11月和1999年1月、4月,对上海潮滩进行连续采样和预测的基础上,用原子吸收法测试了110个表层沉积物中的Cu、Pb、Zn、Cr和Cd的含量,结果表明:(1)上海潮滩表层沉积物重金属含量有如下顺序:Zn〉Cu〉Cr〉Pb》Cd。(2)在自然条件下,从高潮滩到中、低潮滩,沉积物重金属的含量递减。(3)不同的采样位置对沉积物重金属的含量有显著影响。(4)根据各采样点沉积物重金属的含理  相似文献   

8.
洱海水中重金属元素的含量不同,平均值以10^-9计算:Cu1.6,Pb0.59,Zn9.8,Cd0.009,Cr0.24,水质较好;沉积物中每一样品同一元素的含量一般均趋于平均值,以10^-6计算:Cu111,Pb60,Zn127,Cd0.591,Cr130。因此,洱海至今仍是一个较清洁的湖泊。滇池水质较差,内草海段水中重金属元素含量明显上升,以10^-9计算:Cu5.8,Pb0.55,Zn32,  相似文献   

9.
芜湖市城市郊区土壤重金属污染的初步研究   总被引:26,自引:0,他引:26  
通过对安徽省芜湖城市郊区四山、西江、鸠江、马塘4个典型农业区域土壤重金属As、Hg、Pb、Cd、Zn、Cr污染现状的调查与分析,建立了城市郊区土壤重金属污染研究的一般程序和方法.在分析了各典型调查区域环境背景特征的基础上,计算出各区域土壤重金属污染指数,应用对应分析技术,研究了各调查区土壤重金属的污染特征.结果表明,芜湖城市郊区土壤重金属污染已相当显著,且各区域间土壤重金属污染具有一定的差异,总体上鸠江区较其他区域污染严重.各区域间Pb、Hg污染水平差异明显,但As、Cd、Zn、Cr污染差异不大.根据研究结果分析了控制芜湖城市郊区土壤重金属污染的成因.  相似文献   

10.
重金属对大麦(Hordeum vulgare)毒性的研究   总被引:133,自引:1,他引:133  
研究了6种重金属(Hg2+、Cd2+、Pb2+、Ni2+、Cu2+、Zn2+)对大麦幼苗生长及根尖细胞遗传学毒害作用.结果表明,随着重金属浓度的增加和处理时间的延长,大麦种子的萌发率、根生长速率和有丝分裂指数下降.1×10-2mol/L的Hg2+、Cd2+、Pb2+处理24h后完全抑制了细胞分裂,Hg2+、Cd2+和Pb2+诱发的染色体畸变率显著高于Ni2+、Cu2+和Zn2+.用5×10-3—5×10-4mol/L的Hg2+、Cd2+、Pb2+处理24h和Ni2+处理48h后,核仁结构发生分解,形成许多核仁颗粒并进入细胞质中,而Cu2+、Zn2+对核仁结构没有影响.6种重金属对大麦的细胞遗传学毒性顺序为Hg2+>Cd2+>Pb2+>Ni2+>Cu2+>Zn2+.文中还讨论了重金属对植物细胞的毒害机理.  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
Decomposition of alachlor by ozonation and its mechanism   总被引:1,自引:0,他引:1  
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
Removal of cadmium using MnO2 loaded D301 resin   总被引:6,自引:0,他引:6  
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号