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1.
Sewage sludges are potential targets for economic extraction of Au because of the documented Au content of sewage sludges worldwide, which are of the order of some ore deposits currently mined for Au. The sewage of Melbourne, Australia, was stockpiled in large, closed, lagoonal tanks from 1898 until 1980. Reeves, Plimer and Foster, 1999, have conducted, and published, an extensive and exhaustive study of the Werribee sewage reserves utilising RNAA, INAA, GFAAS, ICPMS, and FLAAS to determine 31 elements, including Au, Ag, Sb, As, Cd, Hg, Zn, Cu, and Pb. The study was initiated to determine Au, Ag and other metal variations in both space and time and to investigate the economics of chemical extraction of the precious metals. A total of 149 samples from over 50 hand-auger drillholes to a depth up to 4m were analysed from the stockpiles, with Au assays yielding remarkably consistent results. Average grades of 0.77 g/t Au and 18.8 g/t Ag have been documented for a measured resource of 770,000 m3. Laboratory-based extractive metallurgy of the Werribee sludges has demonstrated that Au, Ag, and Zn can be removed with relative ease by heap-leaching using modified conventional technology, albeit with prohibitive reagent consumption. The extraction of the precious metals also results in the variable removal of contaminant metals such as Cd, As, Sb, Hg and Cr which may render the sludges fit for sale as agricultural fertiliser, provided organic pollutants and pathogenic organisms are below governmental environmental protection limits. 相似文献
2.
南秦岭南部褶皱带是秦岭造山带的重要组成部分，随着找矿勘查工作的深入，相继发现了一系列金、银、锑、铅、锌、铜矿床（点），成为陕西省又一重要有色、贵金属成矿带。南秦岭南部元古宙至中生代多次发生火山成矿作用、沉积或喷流沉积成矿作用和构造-岩浆成矿作用，金、银、锑、铅、锌、铜成矿具有一定的规律，找矿前景好。从资源潜力及经济意义上来看，金应该是该区的主攻矿种。同时，应该兼顾银、锑、铅、锌、铜的找矿工作。开展自水江-留坝成矿带金、银锑找矿、牛山隆起北缘成矿带金铜多金属找矿和红椿坝断裂两侧铜金找矿是主要找矿方向。 相似文献
3.
Immobilization of Cd,Zn and Pb in sewage sludge using red mud 总被引：2，自引：1，他引：1
Sewage sludge is an inevitable end by-product of sewage treatment. Land application provides a cost-effective alternative
for sewage sludge disposal. However, sewage sludge contains heavy metals that may limit its application. In this work, red
mud was employed for the immobilization of heavy metals in sewage sludge. The effect of red mud amendment on heavy metal immobilization
was evaluated using Toxicity Characteristic Leaching Procedure (TCLP) method. The TCLP results showed that the immobilization
efficiency of Cd, Zn and Pb was 100, 92, and 82%, respectively, when sewage sludge was mixed with 10% red mud. Tests carried
out in leaching columns demonstrated that heavy metal concentrations in the leachate of 10% red mud amended sludge were lower
than those of the unamended sludge. Moreover, red mud decreased plant available heavy metal (Cd, Zn and Pb) content from 18.1,
17.2 and 14.6% to 6.9, 11.4 and 7.6%, respectively. Sequential chemical extraction experiments showed that after sludge was
amended with 10% red mud, exchangeable fraction was reduced and iron and manganese oxides fraction was increased. Red mud
amendment can effectively immobilize Cd, Zn and Pb in sewage sludge before land application. 相似文献
4.
A. A. Olajire M. O. Bello M. Abdul-Hammed O. M. Olabemiwo 《International Journal of Environmental Science and Technology》2006,3(4):341-349
Various sludge samples from different domestic and industrial wastewater treatment plants were analyzed by Flame Atomic Absorption Spectrometry (FAAS) to evaluate their total and available contents of heavy metals (Pb, Hg, Cd and Zn). The EDTA, pyridine and acetic acid single extraction techniques were applied to these samples with the objective of studying the leaching behavior of the metals in different sludges and also to predict their possible mobility when these wastes are disposed on the environment and landfills. In EDTA, higher extraction efficiency was observed for major part of the elements studied in the industrial sludges except for Hg and Cd, which were also considerably released from domestic sludges. Acetic acid and pyridine gave a better extraction efficiency for Zn in industrial sludge than EDTA. Moreover, the results of total digestions were compared, for total metal contents, with those obtained using pseudototal digestion procedure and a good correlation (r2 = 0.95) was found between the two methods of digestion. 相似文献
5.
Compacted sewage sludge as a barrier for tailing impoundment 总被引：1，自引：1，他引：0
The feasibility of compacted sewage sludge serving as a barrier for tailing impoundment was evaluated by the batch test and
hydraulic conductivity test with respect to heavy metal retardation and impermeability. The batch test results showed that
the effective removal of heavy metals approached 97.8 and 93.4% for Zn and Cd, respectively. Formation of precipitation of
oxy(hydroxide) and carbonate minerals was mainly responsible for the attenuation of heavy metals in the early period of the
test. Nevertheless, the further removal of heavy metals can be attributed to the sulfate reduction. The hydraulic conductivity
test indicated that almost all of the heavy metals contained in simulated acid pore water were retarded by compacted sewage
sludge. The hydraulic conductivity of the compacted sewage sludge ranged from 3.0 × 10−8 to 8.0 × 10−8 cm s−1, lower than 1.0 × 10−7 cm s−1, which is required by regulations for the hydraulic barrier in landfill sites. Thus, this study suggested that compacted
sewage sludge could be used as a bottom barrier for tailing impoundment. 相似文献
6.
Martin Reich Stephen L. Chryssoulis Carlos Palacios Magdalena Weldt 《Geochimica et cosmochimica acta》2010,74(21):6157-6173
Despite its potential economic and environmental importance, the study of trace metals in supergene (secondary) Cu-sulfides has been seriously overlooked in the past decades. In this study, the concentration and mineralogical form of “invisible” precious metals (Ag, Au) and metalloids (As, Sb, Se, Te) in supergene digenite (Cu1.8S) from various Cu deposits in the Atacama Desert of northern Chile, the world’s premier Cu province, were determined in detail using a combination of microanalytical techniques. Secondary ion mass spectrometry (SIMS) and electron microprobe analyzer (EMPA) measurements reveal that, apart from hosting up to ∼11,000 ppm Ag, supergene digenite can incorporate up to part-per-million contents of Au (∼6 ppm) and associated metalloids such as As (∼300 ppm), Sb (∼60 ppm), Se (∼96 ppm) and Te (∼18 ppm). SIMS analyses of trace metals show that Ag and Au concentrations strongly correlate with As in supergene digenite, defining wedge-shaped zones in Ag-As and Au-As log-log spaces. SIMS depth profiling and high-resolution transmission electron microscopy (HRTEM) observations reveal that samples with anomalously high Ag/As (>∼30) and Au/As (>∼0.03) ratios plot above the wedge zones and contain nanoparticles of metallic Ag and Au, while samples with lower ratios contain Ag and Au that is structurally bound to the Cu-sulfide matrix. The Ag-Au-As relations reported in this study strongly suggest that the incorporation of precious metals in Cu-sulfides formed under supergene, low-temperature conditions respond to the incorporation of a minor component, in this case As. Therefore, As might play a significant role by increasing the solubility of Ag and Au in supergene digenite and controlling the formation and occurrence of Ag and Au nanoparticles. Considering the fact that processes of supergene enrichment in Cu deposits can be active from tens of millions of years (e.g. Atacama Desert), we conclude that supergene digenite may play a previously unforeseen role in scavenging precious metals from undersaturated (or locally slightly supersaturated) solutions in near-surface environments. 相似文献
7.
辽河油田稠油中贵金属分布和赋存状态研究 总被引：1，自引：0，他引：1
以辽河油田稠油为研究对象,通过原子吸收光谱、实沸点蒸馏等手段,研究了辽河油田稠油中Au、Ag、Pt和Pb等贵金属在不同馏分中的分布特征.结果表明,经过实沸点蒸馏后,贵金属不同沸程温度的原油馏分中含量和分布存在很大差异,Au、Ag、Pt、Pd主要集中在渣油馏分中,在沸点》508℃的渣油馏分中Au、Ag、Pt、Pd的比例分别是93.4%、76.9%、73.4%和68.0%;采用选择性萃取的方法对金在稠油中的存在形态的初步研究发现,金在稠油中主要以有机配合物和少量无机配合物形式存在. 相似文献
8.
Fine sludges were collected from five filtration plants, and the partitioning of ten metals (Ag, Cd, Mn, Zn, Pb, Cu, Sn, Co, Ni, and Fe) in them was determined by selective leaching techniques. (1) The available amounts, which shows the total of each metal leached between 1 M CH3COONH4 and 30 percent H2O2, for Ag, Cd and Mn, ranged from 51 to 98 percent for five sludges. (2) The available amounts for Zn, Pb, Cu, and Sn were 47–92 percent for five sludges. (3) The most important fraction for Co, Ni, and Fe, except the Inagawa sludge, which is markedly polluted by organic matter, was the crystalline particle. Therefore, the above metals, except Co, Ni, and Fe, are thought to be enriched on ion-exchangeable sites, organic matter, hydrous Fe/Mn oxides, and sulfides in fine sludges. 相似文献
9.
A routine method for the direct determination of Au and associated trace metals in sulfides has been developed for use with a low-flux nuclear reactor (SLOWPOKE II Reactor Facility, University of Toronto). Small samples (100–200 mg) are analysed simultaneously for Au, Ag, As, Sb, Mo, Co, Se, Cd, Fe, and Zn. Sulfides containing finely divided gold can be analysed with a high degree of precision and yield results which agree closely with commercial fire assay-atomic absorption analyses for Au. Favourable comparisons with other analytical techniques (flameless atomic absorption and emission spectrometry) are also indicated for Ag, As, and Sb. Neutron activation has the advantage of providing precise and accurate results for these elements without chemical separation or preconcentration. Analyses of 10 sulfide-bearing reference materials from CANMET, Ottawa are compared with published best values for selected trace metals including Au. 相似文献
10.
海底块状硫化物(SMS)蕴藏有丰富的Cu、Cd、Au、Fe、Ag、Co等战略性金属,是未来可供人类开发利用的战略资源.本文搜集了全球3 946组SMS化学成分数据,根据构造环境可将其分成4类(快速、中速、慢速、超慢速扩张)洋中脊型和2类(弧后扩张中心和弧火山)岛弧型SMS矿床.利用多元统计方法分析了SMS战略性金属的分布特征和主控因素,探讨了其资源前景.结果表明:洋中脊型SMS矿床富集Cu+Fe+Co±Mo,而岛弧型普遍富集Zn+Pb+Cd+Sb+Ag±Au等关键元素.分析表明,成矿温度、成矿物质来源、酸碱度和氧化还原条件是战略性金属富集的主要影响因素,其中流体温度主要受水深条件控制,成矿物质来源主要受控于构造地质环境,酸碱度和氧化还原性主要受控于围岩类型.Cu+Au+Fe+Co在水深超过约2 650 m的慢速—超慢速扩张脊非转换不连续带和拆离断层带等区域具较好的勘查前景;而Cu+Au+Cd+Ag在水深约1 080~2 160 m的弧后扩张中心区域具较好的勘查前景. 相似文献
11.
Accumulation of lead, cadmium, manganese, copper and zinc by sludge worms; Tubifex tubifex in sewage sludge 总被引：4，自引：4，他引：0
C. C. Kaonga M. Sc J. Kumwenda B.Sc H. T. Mapoma M.Sc 《International Journal of Environmental Science and Technology》2010,7(1):119-126
Tubifex tubifex has been shown to survive in organic polluted environments, however, not much has been done on its inorganic pollution tolerance. Samples of T. tubifex and their respective sewage sludge were taken from Soche wastewater treatment plant in Blantyre City, Malawi during July 2007 to November 2008. The total number of sludge samples taken was fifty one which was made into seventeen composite samples. A total of seventeen T. Tubifex samples were also collected. The samples were analyzed for copper, lead, manganese, zinc and cadmium using standard methods from American Public Health Association and Association of Official Analytical Chemists. The concentrations of metals in sewage sludge and T. tubifex were on dry weight basis and the metals determined were acid extractable. In general, heavy metals concentration was lower in T. tubifex than in sewage sludge. The range of heavy metals concentrations were (in sludge and (T. tubifex)): zinc 275.3–361.5 mg/kg (45.0–82.2 mg/kg), manganese 293.7–230.1 mg/kg (1.21–3.69 mg/kg), copper 86.5–120.1 mg/kg (1.6–4.7 mg/kg), lead 11.2–22.4 mg/kg (Below detection limit–0.95 ) and cadmium 1.12–2.31 mg/kg (1.08–2.18 mg/kg). The results showed significant differences between the concentrations of manganese, copper, lead and zinc in sewage sludge and T. tubifex (p < 0.05). However there was no significant difference between the concentrations of cadmium in sewage sludge and T. tubifex (p > 0.05). T. tubifex did not show the ability to accumulate heavy metals (attributed to its high defecation and metabolic rate) except for cadmium hence cannot be used as a bioindicator for heavy metal pollution in sludge. 相似文献
12.
Steven D. Bussey Paul M. Taufen Bart J. Suchomel Malcolm Ward 《Journal of Geochemical Exploration》1993,47(1-3)
The Bell Springs deposit is a bulk-tonnage, low-grade gold deposit, formed in a hot-spring environment, that is hosted by middle Miocene weakly peralkaline, high-silica rhyolite ash flows and rheomorphic tuffs. Ore grade mineralization over about 460 × 460 m was controlled by northeast- and northwest-trending structures. Sixty-nine soil samples collected along a traverse across the Bell Springs deposit, screened into six mesh size fractions, +10, −10+35, −35+80, −80+120, −120+200, and −200, were treated by low-detection-limit acid digestion/organic extraction procedures, and analyzed by ICP or graphite furnace techniques for Au, Ag, As, Bi, Cd, Cu, Ga, Hg, Mo, Pb, Sb, Se, Te, Tl, and Zn. Twenty-five stream-sediment samples were collected from a drainage crossing mineralization and from a nearby tributary. Sediment size fractions of −200 mesh and −10+200 mesh were analyzed by the same procedures used for soils. In addition, analyses of bulk leachable gold via cyanide leach method (BLEG) was done on bulk −10 mesh sediments.Anomalous Au, Ag, As, Sb, and Mo in all soil size fractions revealed the underlying ore. Areas with anomalous Sb and As were about three times larger than areas with anomalous Au and Ag. Analyses of fine-fractions of stream sediments provided the best-defined Au anomalies in drainages. A multi-element factor calculated by multiplying Au, As, Sb, and Mo reinforced anomalous Au in drainages and correlated well with Bell Springs mineralization. 相似文献
13.
五台山—恒山绿岩带Ａｕ、Ａｇ、Ｃｕ矿床可分为二大类型：（１）再生型金银铜矿，产在包括岩浆岩在内的各类岩石断裂构造中，与岩浆期后热液有关；（２）变生型金银铜矿，产于各类变质岩中，具有层控特征（即绿岩型金矿）。在地球化学特征上，再生型矿床与变生型矿床相比，矿体及围岩中Ｍｏ、Ａｇ、Ｐｂ、Ｚｎ、Ｃｄ等成矿及伴生元素明显富集；Ｋ２Ｏ、Ｒｂ、Ｓｒ、Ｂａ、Ｔｈ、Ｕ也明显富集，是后期岩浆热液作用的结果；Ｈｇ、Ｆ的明显富集则与后期构造活动有关；Ｚｎ／Ｃｄ比值较低，说明受到后期岩浆侵入影响；Ｔｈ／Ｕ比值低，可能指示富钙的酸性岩环境。再生型Ａｕ矿化的元素组合为Ｃｄ、Ａｓ、Ｎｉ、Ａｇ、Ｓｂ、Ａｕ、Ｈｇ（Ｂｉ），再生型Ａｇ矿化的元素组合为Ａｓ、Ｓｂ、Ａｇ、Ｃｄ、Ｃｕ、Ｎｉ（Ｍｏ、Ｐｂ、Ｚｎ、Ｂｉ），变生型Ａｕ矿化的元素组合较简单，只为Ａｕ、Ｈｇ、Ａｓ或Ａｕ、Ｃｕ。上述地球化学特征不仅可以有效地区分矿化类型，而且可以作为地球化学找矿和评价的指标 相似文献
14.
四川大岩子铂-钯矿床的原生地球化学异常特征及盲矿预测 总被引：1，自引：0，他引：1
迄今为止文献中未见有铂矿原生晕研究的报道,通过对大岩子矿区地表和不同中段坑道原生晕的研究,发现在铂-钯矿体周围有清晰的F、Sb、Cd、Hg、As、Ag、Au、Pd、Pt、Cu、Ni元素的原生晕,其中F、Sb、Cd、Hg、As为前缘指示元素,Au、Ag为近矿指示元素,Pt、Pd、Cu、Ni为成矿指示元素.元素的垂直分带序列为(地表至矿体):(F、Sb、Cd、Hg、As)-(Ag、Au)-(Pd、Pt)-(Cu、Ni).地表岩石地球化学测量发现的Ⅲ号Pd、Pt异常带,具有多元素异常组合特征,判断为矿致异常,推测在该异常带下方可望找到隐伏矿体.坑道原生晕研究发现,在PD4中段出现浓集中心醒目、浓度分带清晰的F原生晕,推测在PD4中段下方可能存在新的盲矿体. 相似文献
15.
污泥屏障渗透性及重金属阻截效果试验研究 总被引：1，自引：0，他引：1
目前,废弃物处置场渗滤液中的重金属污染物只能依靠极低渗透性的水力屏障来控制,还不存在利用化学场专门拦截重金属污染物的反应型屏障。在有机结合生活污泥的低渗透性与丰富的有机质和厌氧微生物特性的基础上,提出“污泥屏障”的构想。研究利用柔性壁渗透仪测量不同有效应力作用下生活污泥试样的渗透系数,并对渗出液的化学性质进行了监测,验证污泥屏障的可行性。试验结果表明：随着有效应力的增大,污泥试样干密度提高,渗透系数的对数值随孔隙比的减小线性降低。试样内部微生物厌氧呼吸形成的生物膜和无机物沉淀以及黏土颗粒双电层厚度的增大,也是污泥渗透系数降低的原因,污泥渗透系数仅为 数量级。另外,污泥强烈吸附能力及厌氧微生物呼吸作用形成的中-弱碱性还原环境,对渗透液中的Zn和Cd都起到了很好的拦截作用。 相似文献
16.
Water, soil, suspended load and biomass samples were collected from a sewage and sludge treated lake (Lake Dalavayi) around Mysore, Karnataka, India. The polluted lake water is mainly used for irrigation and domestic purposes. The samples have been analysed for heavy metals (Cu, Cr, Co, Cd, Ni, Fe, Mn, V, Zn, Sr) and cations (Ca, Na, Mg) by Inductively Coupled Plasma Emission Spectrometer (ICP) model Labtam 8500. With the exception of water, all the matrices suspended particulate matter, lake bed sediment and biomass of the lake show high concentrations of heavy metals and cations when compared to the World Health Organization (WHO) standard, indicating metal toxicity in this lake. Additional inputs of soaps and detergents carried by sewage water are causing the eutrophication of the lake. Elevated levels of heavy metal toxicity, especially Co and Cd, are indicated by the bioindicator Eichornia cressepes (water hyacinth), which, using these metals as micronutrients, has grown luxuriously over the lake water, further augmenting the death of lifeforms in the lake. 相似文献
17.
为探讨深度脱水污泥作为垃圾填埋场覆盖材料在湿润气候区的服役性能,将杭州主城区污水处理厂处理后的深度脱水污泥分别在蒸馏水、渗滤液中浸泡一个月和两个月,测试其强度和渗透特性的变化规律,并与填埋场覆盖层常用的黏性土进行了对比。试验结果表明,相对于一般污泥,深度脱水污泥的无侧限抗压强度较高,但在渗滤液和蒸馏水中浸泡两个月后分别降低5.4%和18.9%。在蒸馏水和渗滤液中浸泡两个月的深度脱水污泥黏聚力有所降低,而有效内摩擦角提高约7.5°;在浸泡水和渗滤液后,脱水污泥的渗透系数提高约3～5倍。该深度脱水污泥应用于填埋场覆盖材料时,其强度达到城镇污水处理厂污泥填埋控制要求。 相似文献
18.
19.
The physicochemical formation conditions of Au-As, Au-Sb, and Ag-Sb ores characterized by similar paragenetic mineral assemblages and sets of major ore elements but differing in their proportions have been studied. The composition of the solutions filling fluid inclusions in minerals of Au-Sb deposits, combined with mineralogical and geochemical data, indicates that these deposits were formed from a near-neutral to alkalescent chloride-sulfide (<5 wt % NaCl) solution. Au-As and Au-Sb deposits were formed from fluids of the same type, consisting of a predominately CO2-CH4 gas phase with N2 and a low-saline chloride-sulfide solution, where Au and Ag were predominantly transported as dihydrosulfide species and Sb as sulfide and hydroxy complexes. Superimposed minerals of the sulfide-sulfosalt stage that precipitated from chloride-rich solutions (up to 30 wt % NaCl equiv), which contained Ca and Fe chlorides in addition to NaCl, are identified at some Au-Sb deposits. These solutions are similar in composition to the ore-forming fluids of Ag-Sb deposits. Chloride complexes are dominant Au and Ag species in acid chloride-rich solutions of Ag-Sb deposits (up to 38 wt % NaCl equiv), while chloride and hydroxy complexes are characteristic of Sb. These solutions are distinguished by high concentrations of Ag, Sb, Cu, Fe, Mn, Bi, Pb, and Zn. The mineralogical and geochemical specialization of Ag-Sb ore is caused by chemical features of highly concentrated chloride solutions enriched in Ag, Sb, and Cu and by a relatively low Au content within the pH interval 3.5–4.0 (10?6 m). The factors controlling formation of Au-As deposits are a high capacity of a low-chloride sulfide solution with respect to metals and a high Au concentration therein (two orders higher than that of solutions of Ag-Sb deposits). The enrichment of the pyrite-arsenopyrite paragenetic assemblage in gold is a result of juxtaposed stability fields of native gold, arsenopyrite, and pyrite and their mass deposition with a decrease in temperature from 400 to 300°C. The main cause of the specific mineralogy and geochemistry of Au-Sb deposits is a high metal capacity of a near-neutral low-chloride sulfide fluid with respect to Sb, Au, and Ag, but a low Ag content. The mineralogical and fluid inclusion data combined with computer thermodynamic simulation allowed us to establish the factors of ore formation at P-T-X parameters close to natural conditions and made it possible to characterize the joint deposition of gold and silver in quantitative terms. 相似文献
20.
Amir Mohseni Adel Reyhanitabar Nosratollah Najafi Shahin Oustan Kambiz Bazargan 《Arabian Journal of Geosciences》2018,11(14):384
The aim of this study was to determine the influence of sewage sludge (SLU) amendment on the desorption characteristics of zinc (Zn), lead (Pb), and cadmium (Cd) in contaminated calcareous soils. Three levels of SLU (0, 1, and 3% w/w) were added to the two calcareous contaminated soils. Samples were incubated for 30 days and equilibrated with 0.005 M DTPA for 0.25 to 240 h. The addition of SLU significantly increased the amount of DTPA-extractable Zn in soils. While the amounts of Cd, Pb, dissolved organic carbon (DOC), and pH showed a significant increase only in 3% w/w of SLU, with the exception of Cd desorption in 1% w/w of SLU, kinetics of Zn, Pb, and Cd extraction increased together with an increase in the level of applied SLU. The best models for describing desorption data were explicitly power function and Elovich. The rate constants of Zn and Pb had significant correlations with DTPA-extractable Zn and Pb, DOC and pH, which affect Zn and Pb desorption. Also, the rate constants of Cd had significant correlations with CEC that can be deemed as equivalent to the fact that Cd desorption is controlled by surface adsorption, particularly in the lower sludge application amount. These results can be used for management of sewage sludge application in contaminated calcareous soils. 相似文献