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791.
污泥对樟子松生物量及其重金属积累和土壤重金属有效性的影响 总被引:2,自引:0,他引:2
采用盆栽试验研究了不同剂量污泥(体积分数,即污泥体积占污泥和沙土总体积的百分比,分别为:0、20%、33.3%、50%和100%)施用于风沙土条件下,污泥剂量对樟子松幼苗生物量及其对重金属的累积和土壤中重金属有效性的影响.结果表明,在养分含量低的风沙土中,施用污泥能够显著提高樟子松幼苗生物量,最适剂量为50%;污泥剂量的增加可促进樟子松植株对重金属的吸收和累积,在最适剂量(50%)条件下,樟子松植株中Cu、Cd、Pb、Zn的累积量分别是对照(不施污泥)的18.0、8.9、17.1、11.5倍;樟子松植株重金属吸收速率顺序为:ZnCuPbCd,而迁移系数顺序为:ZnCdCuPb;土壤中有效态重金属含量随污泥剂量的增加而增加,而植株收获后土壤中有效态重金属下降幅度均小于对照. 相似文献
792.
北京北部水系沉积物中重金属的研究 总被引:12,自引:1,他引:11
主要研究了北京市北部水系沉积物中重金属(As、Hg、Cd、Cr、Cu、Mn、Ni、Pb、Ti和Zn)含量和来源.在潮白河及密云水库流域采集了17个沉积物样品,温榆河流域采集了5个样品,重金属含量As和Hg采用原子荧光光谱法测定,Cd、Cr、Cu、Mn、Ni、Pb、Ti和Zn含量用电感耦合等离子发射光谱法测定.研究结果表明,沉积物中重金属元素没有出现明显的富集状况,只有Hg、Cd、Cr和Zn在一些采样点有较高的富集.相关性分析表明Hg、Cd、Zn和Cu互相之间呈显著正相关(r0.06;p0.01),而Hg与Cr、Mn、Ni、Pb和Ti没有明显的相关性.通过主成分分析研究重金属的来源,发现前3个主成分贡献率分别为38%、23%和17%.因此,Hg、Cd、Zn和Cu作为第一主成分被认为与人类活动的工矿业开采有关,第二主成分As和Mn与人类活动的农业生产和生活污水排放有关,第三主成分Cr、Ni和Ti与岩石风化和土壤侵蚀有关. 相似文献
793.
采用重庆同兴垃圾焚烧发电厂产生的焚烧飞灰,在感应炉上进行熔融处理实验研究,探讨了熔融温度、熔融时间、碱度等因素对熔融过程中重金属分离效果的影响.结果表明,重金属的挥发率按其熔沸点高低区分明显,Pb、Zn和Cd的挥发率较高,分别为80%、60%和95%左右;Cr、Mn的挥发率均低于10%.随着熔融时间、熔融温度和碱度的增加,Pb、Zn、Cd、Mn、Cr的挥发率变化趋势不明显;铁浴熔融方式可进一步促进Zn、Pb、Hg的挥发,有利于Cr、Cu从熔渣中分离出来,与生铁形成合金.对熔渣的浸出毒性测试结果表明,重金属元素的浸出毒性均可达标(GB5085.3-1996). 相似文献
794.
广州市污水污泥中的重金属及其农用探讨 总被引:4,自引:1,他引:3
分析了广州市6种污水污泥中重金属(Zn,Cu,Pb,Cr,Mn和Ni)质量分数及其存在形态,并对污泥农业利用过程中施用的最大量进行了估算.结果表明:广州不同来源污水污泥中.(Cu),w(Zn),w(Mn)和,(Ni)较高,变幅较大,而w( Ph )和w( Cr)低.除一种污泥中w(Cu)超标外,其他重金属基本符合国家农用控制标准(G1318918-2002),但所有污泥中重金属质量分数都超过广州市农田土壤平均值.不同重金属以及同一重金属在不同污泥中的形态分布也不同,其中Zn,Mn和Ni的潜在迁移性强,Cu和Cr中的还原态占有很大的比例,污泥中Pb主要以还原态和残渣态存在.根据广州市主要旱地赤红色土壤静态环境容量和动态环境容量计算表明,污泥农用过程中Cu和Zn是主要监控污染元素,不同来源污泥的最大施用量有明显差异.为保证土壤环境的安全,建议将Cu和Zn作为控制城市污水污泥农用过程中最高施用量的计算参考指标. 相似文献
795.
Gallic acid和SDS对黑麦草体内重金属亚细胞及形态分布的影响 总被引:2,自引:1,他引:1
通过盆栽试验,研究了投加螯合剂没食子酸gallic acid(5mmol·kg-1)与表面活性剂十二烷基磺酸钠SDS(1mmol·kg-1)对黑麦草(Lolium perenneL.)体内重金属亚细胞及形态分布的影响.结果表明,单独投加gallicacid增强了黑麦草对Cd、Pb的区室化作用及对Zn的细胞壁沉积作用;复合投加gallic acid和SDS增强了黑麦草对Cd的区室化作用和细胞壁沉积作用,以及对Zn的细胞壁沉积作用.单独投加gallic acid使黑麦草体内Cd、Zn总量分别增加了33.5%和6.0%,其中,惰性态Cd、Zn所占比例分别增加了6.2%、6.3%;复合投加gallic acid和SDS使黑麦草体内Cd总量增加了35.6%,Zn总量减少了1.1%,其中,惰性态Cd、Zn所占比例分别增加了7.2%、8.6%,增强了植物对Cd、Zn的螯合作用.各处理对Pb的亚细胞分布及形态无明显影响. 相似文献
796.
一株Zn抗性菌株的筛选鉴定及吸附条件优化 总被引:1,自引:0,他引:1
采用浓度梯度法从铅锌尾矿区与污水灌溉区土壤中筛选了一株Zn抗性放线菌,并通过形态与培养特征、生理生化特性、细胞壁组分与16SrRNA基因序列分析对该菌株进行了鉴定.同时,综合运用单因素试验与正交试验法对该菌株吸附Zn2+的条件进行了优化.结果表明,菌株CCNWHX72-14经鉴定为高加索链霉菌(Streptomyces ciscaucasicus),其对Zn2+的抗性达到845mg·L-1.锌胁迫生长曲线表明,该菌株在130mg·L-1Zn2+胁迫时生长良好,且最适培养时间为7d.各个单因素条件对该菌株吸附Zn2+的影响顺序为:接种量初始Zn2+浓度初始pH转速温度.该菌株吸附Zn2+的最佳条件为:初始Zn2+浓度为150mg·L-1,初始pH=5,接种量为1%,转速为60r·min-1,温度为28℃.菌株CCNWHX72-14在最佳条件下对Zn2+的吸附较具有良好的重复性与稳定性,最高吸附量可达51.05mg·g-1,该研究为进一步探讨链霉菌的Zn2+吸附机制及其在生物修复中的应用奠定了基础. 相似文献
797.
Strength development,leachability and microstructure of heavy metals from the solidified waste using synthesis rice husk ash (sRHA) and lime blended at the weight ratio of 1:1 were used as binders.The heavy metal-containing sludge was used at the level of 0 wt.%,30 wt.%,and 50 wt.% dry weight,respectively.The sample specimens with and without 1.5 wt.% of sodium silicate (SiO 2 /Na 2 O=1.0) were cured under the ambient condition and elevated temperature curing at 50°C for 24 hr.Experimental results showed that the introduction of sodium silicate solution and elevated temperature curing to sRHA-based solidified waste containing 30 wt.% of heavy metal sludge gave one day strength of 20 kg/cm 2 compared to 0.9 kg/cm2 for the control sample.XRD patterns indicated that most metal-sulfides present in the sludge were appeared in the solidified waste and SEM coupled with EDX techniques reveal these metal-sulfide particles were trapped within the lime-sRHA matrices.In addition,cumulative leaching behavior by tank test (EA NEN 7375:2004) showed that solidified waste containing up to 30 wt.% of heavy metal sludge was suitable to dispose in a secured landfill. 相似文献
798.
Treatment of oilfield produced water was investigated using an anaerobic process coupled with micro-electrolysis (ME), focusing
on changes in chemical oxygen demand (COD) and biodegradability. Results showed that COD exhibited an abnormal change in
the single anaerobic system in which it increased within the first 168 hr, but then decreased to 222 mg/L after 360 hr. The biological
oxygen demand (five-day) (BOD5)/COD ratio of the water increased from 0.05 to 0.15. Hydrocarbons in the wastewater, such as pectin,
degraded to small molecules during the hydrolytic acidification process. Comparatively, the e ect of ME was also investigated. The
COD underwent a slight decrease and the BOD5/COD ratio of the water improved from 0.05 to 0.17 after ME. Removal of COD was
38.3% under the idealized ME conditions (pH 6.0), using iron and active carbon (80 and 40 g/L, respectively). Coupling the anaerobic
process with ME accelerated the COD removal ratio (average removal was 53.3%). Gas chromatography/mass spectrometry was used
to analyze organic species conversion. This integrated system appeared to be a useful option for the treatment of water produced in
oilfields. 相似文献
799.
Paulownia fortunei has been successfully used in the phytoremediation of many Pb/Zn mine tailings. However, seed germination and young seedlings of P. fortunei rarely occurred in these mine tailings. The physiological responses and detoxific mechanisms of P. fortunei young seedling to Pb, Zn, Cu and Cd stress were investigated. The germinated rate, shoot length, chlorophyll and carotenoid contents in leaves of young seedlings had a great reduction under Zn and Cu treatments, but had little decrease under Pb and Cd treatments. The production rate of O2•−, H2O2 and malondialdehyde (MDA) contents significantly increased in response to added Zn and Cu indicating great oxidative stress for young seedlings, but they had no significant change to added Pb and Cd. Young seedlings had effective detoxific mechanism to Pb and Cd, as antioxidant enzymes activities, phytochelatins (PCs-SH) and proline contents increased with increasing rates of added Pb and Cd. However, young seedlings had un-effective detoxific mechanisms to Zn and Cu stress. Results revealed the heavy metals (such as Cu) that present at low concentrations in mine tailings may be major constraint for the survival of young seedlings. 相似文献
800.
Influence of Indian mustard (Brassicajuncea) on rhizosphere soil solution chemistry in long-term contaminated soils: A rhizobox study 总被引:1,自引:0,他引:1
This study investigated the influence of Indian mustard (Brassica juncea) root exudation on soil solution properties (pH, dissolved
organic carbon (DOC), metal solubility) in the rhizosphere using a rhizobox. Measurement was conducted following the cultivation
of Indian mustard in the rhizobox filled four di erent types of heavy metal contaminated soils (two alkaline soils and two acidic
soils). The growth of Indian mustard resulted in a significant increase (by 0.6 pH units) in rhizosphere soil solution pH of acidic
soils and only a slight increase (< 0.1 pH units) in alkaline soils. Furthermore, the DOC concentration increased by 17–156 mg/L
in the rhizosphere regardless of soil type and the extent of contamination, demonstrating the exudation of DOC from root. Ion
chromatographic determination showed a marked increase in the total dissolved organic acids (OAs) in rhizosphere. While root exudates
were observed in all soils, the amount of DOC and OAs in soil solution varied considerably amongst di erent soils, resulting in
significant changes to soil solution metals in the rhizosphere. For example, the soil solution Cd, Cu, Pb, and Zn concentrations increased
in the rhizosphere of alkaline soils compared to bulk soil following plant cultivation. In contrast, the soluble concentrations of Cd, Pb,
and Zn in acidic soils decreased in rhizosphere soil when compared to bulk soils. Besides the influence of pH and DOC on metal
solubility, the increase of heavy metal concentration having high stability constant such as Cu and Pb resulted in a release of Cd and
Zn from solid phase to liquid phase. 相似文献