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1.
两株耐铅镉真菌对土壤中铅镉赋存形态及小白菜吸收积累的影响 总被引:2,自引:1,他引:2
通过土培试验,研究接种耐铅镉真菌(产黄头孢霉Cephalosporium chrysogenum和头孢霉Cephalosporium SP.)对灭菌和未灭菌铅镉污染土壤上小白菜生长及铅镉赋存形态的影响.试验结果表明:接种两种耐重金属真菌可以降低或显著降低土壤中交换态铅镉、碳酸盐结合态铅镉和铁锰结合态铅镉,且显著增加土壤中有机结合态铅镉,因此降低了土壤中铅镉的活性;在灭菌和未灭菌铅镉污染土壤上接种两种真菌均能增加或显著增加小白菜的株高和鲜重,其中在未灭土壤中接种产黄头孢霉20 mL小白菜鲜重和株高最大,分别达到6.00 cm和3.22 g·株~(-1),在灭菌土壤上接种产黄头胞霉10 m L小白菜株高和鲜重最大,分别为10.66 cm和11.07 g·株~(-1);接种两种真菌可以显著降低未灭菌土壤上小白菜体内铅镉含量和累积量,在灭菌土壤上接种10 mL产黄头孢霉可以显著降低小白菜铅含量和累积量. 相似文献
2.
Phytoremediation potential of charophytes: Bioaccumulation and toxicity studies of cadmium, lead and zinc 总被引:1,自引:0,他引:1
Najjapak Sooksawat Metha Meetam Maleeya Kruatrachue Prayad Pokethitiyook Koravisd Nathalang 《环境科学学报(英文版)》2013,25(3):596-604
The ability for usage of common freshwater charophytes,Chara aculeolata and Nitella opaca in removal of cadmium (Cd),lead (Pb) and zinc (Zn) from wastewater was examined.C.aculeolata and N.opaca were exposed to various concentrations of Cd (0.25 and 0.5 mg/L),Pb (5 and 10 mg/L) and Zn (5 and 10 mg/L) solutions under hydroponic conditions for 6 days.C.aculeolata was more tolerant of Cd and Pb than N.opaca.The relative growth rate of N.opaca was drastically reduced at high concentrations of Cd and Pb although both were tolerant of Zn.Both macroalgae showed a reduction in chloroplast,chlorophyll and carotenoid content after Cd and Pb exposure,while Zn exposure had little effects.The bioaccumulation of both Cd and Pb was higher in N.opaca (1544.3 μg/g at 0.5 mg/L Cd,21657.0 μg/g at 10 mg/L Pb) whereas higher Zn accumulation was observed in C.aculeolata (6703.5 μg/g at 10 mg/L Zn).In addition,high bioconcentration factor values (> 1000) for Cd and Pb were observed in both species.C.aculeolata showed higher percentage of Cd and Pb removal (> 95%) than N.opaca and seemed to be a better choice for Cd and Pb removal from wastewater due to its tolerance to these metals. 相似文献
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A field trial was conducted to evaluate the reduction of bioavailability of heavy metals including lead (Pb), zinc (Zn) and cadmium (Cd) in a soil contaminated by mining tailings in Shaoxing, Zhejiang, China. Three commercial phosphate (P) fertilizers including phosphate rock (PR), calcium magnesium phosphate (CMP), and single superphosphate (SSP) were applied to the plot at three P application rates, 50, 300, and 500 g/m2 with 9 treatments and control (CK). Plants, water soluble and exchangeable (WE) extra... 相似文献
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腐殖酸对土壤铅镉吸附、赋存形态及生物可给性的影响 总被引:2,自引:0,他引:2
腐殖酸(HAs)对重金属土壤环境行为及其生物有效性的影响与其组分分子量大小关系密切.通过3种in vitro试验方法(PBET、SBRC、IVG)探讨了HAs不同分子量组分(F1:<5kDa、F2:5~10kDa、F3:10~30kDa、F4:>30kDa)对土壤镉(Cd)、铅(Pb)生物可给性的影响,同时结合批量等温吸附实验、化学连续提取形态分级方法,分析了土壤Cd、Pb吸附和形态转化与生物可给性的关系.结果表明:土壤对Cd、Pb吸附能力既受HAs添加量的影响,也受到HAs分子量大小的影响.HAs添加量为0.2% C~1% C条件下,<5kDa分子量组分促进了土壤对Cd、Pb的吸附,且随着HAs添加量的增加,促进作用更强.而>10kDa的其他组分则降低了土壤吸附Cd、Pb的能力.在本试验HAs添加量范围内,不同组分均促进了土壤中酸提取态Cd向残渣态转化,且低分子量组分对其促进作用更强.土壤Pb2+主要以可还原态的形式存在,占57%~89%,随着HAs组分分子量的增加,酸交换态Pb占比逐渐下降,HAs的添加促进了活性态Pb向难利用态Pb转化,从而降低了Pb2+活性.3种in vitro方法生物可给性测定结果表明,<5k和5~10k组分均提高了胃、肠阶段土壤Cd、Pb生物可给性(BACd、BAPb),而其余组分则使土壤Cd、Pb生物可给性降低.Cd、Pb生物可给性取决于Cd、Pb在土壤中转化平衡后的赋存形态,酸交换态占比高生物可给性相应也越高,土壤对重金属的吸附固定难以反映生物可给性. 相似文献
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土壤微生物活性对石油原油、铅镉及其复合污染的响应 总被引:8,自引:1,他引:8
随着工农业生产的迅猛发展、石油原油及重金属等原材料的广泛开采与使用,使石油原油、重金属及其复合污染日趋加重,对环境及人类的危害也越来越大.采用室内培养试验,利用人工模拟污染土壤,研究石油原油、铅镉及其复合污染胁迫对土壤微生物活性的影响.试验设置4个处理:1新鲜土壤(S)作为对照;21000 mg·kg~(-1)石油原油污染土壤(SP);3500 mg·kg~(-1)铅和50 mg·kg~(-1)镉污染土壤(SH);41000mg·kg~(-1)石油原油污染、500 mg·kg~(-1)铅和50 mg·kg~(-1)镉复合污染土壤(SPH).结果表明:与对照相比,SH、SP、SPH处理土壤基础呼吸强度最高分别增加约100.99%、36.61%、25.80%,铅镉污染(SH)对土壤基础呼吸影响最显著,反映出重金属污染对土壤基础呼吸的激活作用最强;石油原油污染(SP)与石油原油及铅镉复合污染(SPH)刺激土壤微生物量碳增加,SP处理最高增加了90.25%,而铅镉污染(SH)则使土壤微生物量碳减少.不同土壤酶对污染处理的响应不同,其中,石油原油污染(SP)对FDA水解酶及脱氢酶活性表现为激活作用;石油原油或石油原油及铅镉复合污染(SP、SPH)对脲酶及过氧化氢酶活性主要表现为激活作用,而铅镉污染(SH)对脲酶及过氧化氢酶活性主要表现为抑制作用.该研究表明,石油原油及铅镉复合污染对土壤微生物活性的影响与石油原油或铅镉污染的影响不同,它们之间存在着明显的交互作用. 相似文献
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Guangxu Liu Xueliang Chai Yanqing Shao Lihua Hu Qilang Xie Hongxi Wu 《环境科学学报(英文版)》2011,23(2):330-335
Computer assisted movement tracking was used to characterize the motility of two marine microalgae, Isochrysis galbana
and Tetraselmis chui, and to investigate the toxicity of Cu, Pb, and Cd on motile percentage, curvilinear velocity, average path
velocity, straight line velocity, linearity, straightness, and wobble. Except for motile percentage, all other motility parameters di ered
significantly between I. galbana and T. chui. Based on relative motile percentage data, the median e ective concentration (EC50) of Cu
on the motility of I. galbana and T. chui was 31.4 and 1.3 mol/L, respectively, while for Pb it was 37.8 and 10.9 mol/L and for Cd it
was 121.6 and 37.8 mol/L, respectively. Compared to I. galbana, T. chui was more sensitive to all tested metals. The toxic e ect of the
heavy metals on motility exhibited the following decreasing order for both species: Cu > Pb > Cd. Our results indicate that I. galbana
and T. chui motility is sensitive to heavy metals and can be used as an indicator for toxicology bioassays. 相似文献
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Influences of phosphate nutritional level on the phytoavailability and speciation distribution of cadmium and lead in soil 总被引:1,自引:0,他引:1
IntroductionNorth-east China is one of the most importantindustrial bases and also a main agriculturalproduction area. Land disposal of wastes and irrigatingwith sewage have led to increasing heavy metalcontents in soil (Chen, 1996) and the problemsinduce… 相似文献
11.
汞、镉、铅和砷是自然界中毒性较强的金属,镉和砷已确定为致癌物,汞和铅为可能致癌物。人类活动过程的排放是汞、镉、铅和砷的主要污染来源,由这些金属污染物暴露导致的人类疾病已经引起了公众的广泛关注。研究汞、镉、铅和砷在环境中实际暴露水平,尤其是汞、镉、铅和砷复合暴露对人体健康和生态环境影响及毒性效应的机理极为重要。根据暴露途径、暴露剂量和暴露时间,汞、镉、铅和砷具有不同的代谢途径,产生不同的毒性效应,具有不同的毒性效应机理。在总结现有汞、镉、铅、砷单一和混合暴露的健康损害及毒性效应的基础上,回顾、归纳汞、镉、铅和砷诱导产生毒性效应的机理,讨论基因组、转录组、蛋白质组和代谢组学等技术在汞、镉、铅和砷单一、混合毒性效应及机理研究中的应用并探讨 来的研究方向。 相似文献
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MnO2-loaded D301 weak basic anion exchange resin has been used as adsorbent to simultaneously remove lead and cadmium
ions from aqueous solution. The e ects of adsorbent dosage, solution pH and the coexistent ions on the adsorption were investigated.
Experimental results showed that with the adsorbent dosage more than 0.6 g/L, both Pb2+ and Cd2+ were simultaneously removed at
pH range 5–6. Except for HPO4
2??, the high concentration coexistent ions such as Na+, K+, Cl??, NO3??, SO4
2?? and HCO3??, showed no
significant e ect on the removal e ciency of both Pb2+ and Cd2+ under the experimental conditions. The coexistence of Mg2+, Ca2+
caused the reduction of Cd2+ removal, but not for Pb2+. The adsorption equilibrium for Pb2+ and Cd2+ could be excellently described
by the Langmuir isotherm model with R2 > 0.99. The maximum adsorption capacity was calculated as 80.64 mg/g for Pb2+ and 21.45
mg/g for Cd2+. The adsorption processes followed the pseudo first-order kinetics model. MnO2-loaded D301 resin has been shown to
have a potential to be used as an e ective adsorbent for simultaneous removal of lead and cadmium ions from aqueous solution. 相似文献
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化学污染物通常以混合物的形式存在,其中重金属和有机化学物质是环境中常见的两大类污染物,它们的毒性效应长期受到关注。由于化学污染物混合物毒性效应的复杂性和研究方法的限制,现有研究大多关注污染物单一毒性效应和同一类化学污染物联合毒性效应,而对不同类型化学污染物联合毒性效应研究甚少。在系统分析、总结2,3,7,8-四氯代二苯并二英(TCDD)和汞、镉、铅、砷的环境来源、环境浓度、单一及联合毒性效应和分子机理研究的基础上,结合对单一和混合物诱导表达基因的转录组分析,基因表达水平的定量研究以及代谢组学、暴露组学等技术在联合毒性效应与机理研究中的应用前景,提出基于特异性基因表达水平来研究、评价联合毒性效应的方法。 相似文献
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在外源Cd^2 处理梯度下,综合探讨细胞壁的阻隔作用、细胞活性氧防御酶系作用、植物细胞的区间隔离作用及有机酸生成等几种解毒机制对抗性的贡献。结果表明:(1)细胞壁及残渣、含核糖核蛋白体的细胞溶质部分是结合镉的主要部位,细胞核、叶绿体和线粒体结合镉量较少;(2)解毒功能强的品种并非都是对镉吸收量少的品种,吸收量少的品种也并不意味着就有较强的解毒功能,解毒是多种机制综合作用的结果;(3)POD在Cd^2 处理下小麦细胞活性氧防御机制中起关键作用;(4)低浓度Cd^2 处理下,5个小麦品种有机酸生成量变化不明显。随Cd^2 处理浓度升高,有机酸生成量增加;(5)小麦品种FM27、FM29是解毒功能较强的品种,FM24、FM25居中,M较差。 相似文献
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Speciation and bioaccessibility of lead and cadmium in soil treated with
metal-enriched Indian mustard leaves 总被引:1,自引:0,他引:1
Indian mustard (Brassica juncea (L.) Czern.) has shown good potential for the phytoremediation of soil contaminated with heavy
metals. However, there is little information about the speciation and bioaccessibility of heavy metals in soil during the decomposition
of metal-rich Indian mustard leaves. Incubation experiments (1-, 3-, and 6-month) were carried out in Beijing and Hunan soil with
metal-rich Indian mustard leaves addition (1% and 3%) and the e ects of mustard leaves addition on the speciation and bioaccessibility
of heavy metals were studied. The results showed that the addition of mustard leaves led to significant increases in pH and DOC
in the Hunan soil. Both 1% and 3% of mustard leaf amendment caused the percentage of the exchangeable (F1), precipitated with
carbonates (F2), bound to Fe/Mn oxides (F3) and bound to organic matter (F4) fractions of Pb and Cd to increase dramatically, while
the percentage of the residual fraction (F5) of Cd and Pb significantly dropped in both Beijing and Hunan soils. Mustard leaf addition
caused the bioaccessibility of Pb to decrease in the gastric phase, whereas the values increased in the small intestinal phase. The Cd
bioaccessibility increased with mustard leaf addition in both the gastric and small intestinal phases. In conclusion, the metal-enriched
mustard leaves addition induces Pb and Cd concentrations and their mobility increasing in the Beijing and Hunan soils. Therefore,
heavy metal risk in metal-enriched plant leaves should be considered in phytoremediation system in which heavy metal might be
brought back to soil and changed over time. 相似文献
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菲律宾蛤仔对锌、铅的积累特征 总被引:18,自引:0,他引:18
菲律宾蛤仔(RuditapesphilippinarumAdamsetReve(Bivalvia:Veneridae))分别在不同系列Zn和Pb浓度下培养20d,每间隔5d测定菲律宾蛤仔体内Zn、Pb含量.结果表明,菲律宾蛤仔在水体Zn浓度100μg/L以下Zn积累量低,在水体Zn浓度为200μg/L时Zn积累量高.菲律宾蛤仔在水体Pb浓度为32μg/L以下暴露5dPb积累量低,但在水体Pb浓度为32μg/L中暴露15d,菲律宾蛤仔体内Pb含量可达对照组的5倍.可见,菲律宾蛤仔对Zn、Pb的积累量不仅与水体中Zn、Pb浓度有关,而且与暴露时间有关. 相似文献
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采用体内试验和体外试验方法,观察氯化镉对小鼠免疫功能的影响。免疫后不同时间,给小鼠一次灌胃30mg/kgCdCl2,未见对免疫功能产生明显影响。反复多次灌胃染毒14天,在0.3mg/ks/d组可见明显抑制小鼠脾淋巴细胞IgM-pFC,抑制率为42.1%。体外试验表明,12.5μmol/LCdCl2与淋巴细胞作用48h,25μmol/LCdCl2作用72h,对淋巴细胞增殖反应抑制率分别为38.3%和77.8%,以上结果表明氟化钢具有明显的免疫毒性。 相似文献
18.
LIN Min 《环境科学学报(英文版)》2000,(4)
IntroductionThemetalmeltingindustryisoneofthelargerindustriesworld wide ,includingironandsteelfoundriesandmills,aswellasbrassandbronzefoundries (Morgan ,1 977;Gill,1 981 ;Brooks,1 991 ;Collie ,1 984;Swarnkar,1 996 ;Peters,1 992 ;Elgersma,1 992 ) .Duringthemetalmeltingprocess,theele… 相似文献
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LIN Min 《环境科学学报(英文版)》2000,12(4):452-457
In this work, a thorough examinations on the extractability of zinc and lead present in the steelmaking dusts using alkaline leaching process and the effectiveness of the zinc and lead separation in the resultant leaching solutions using sulfide precipitation method were made. It was found that only about 53% of zinc and over 70% of the lead could be leached out of the dusts, while the other 47% of zinc and 306 of lead were left in the leaching residues. The zinc and lead in the resultant leaching solution can be effectively and selectively separated. When the weight ratio of sodium sulfide (M. W. = 222-240) to Pb was kept at 1.8, the lead in the solution could be precipitated out quantitatively while all the zinc was remained in the solution. The zinc left in the solution can be further recovered by the addition of extra sodium sulfide with a weight ratio of sodium sulfide to the zinc over 2.6. The resultant filtrate can be recycled to the leaching of dust in the next leaching process. 相似文献