Exploitation of gold in a historic sewage sludge stockpile, Werribee, Australia: resource evaluation, chemical extraction and subsequent utilisation of sludge     

Shane J. Reeves  Ian R. Plimer  David Foster 《Journal of Geochemical Exploration》1999,65(2):397

Sewage sludges are dewatered end products of human sewage waste and are recognised repositories of organic pollutants and heavy metals. They may be considered 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. They are also highly nutrient enriched (nitrogen and phosphorus) and therefore amenable to use as agricultural fertiliser or as covers for mine wastes. The sewage of Melbourne, Australia, a city with a current population of 3.3 million, was stockpiled in large, closed, lagoonal tanks from 1898 until 1980. In 1995 Echidna Mining, an Australian gold exploration company, acquired the exploration rights to the ground surrounding the historic sludge reserves and commenced a program of resource evaluation, utilising RNAA, INAA, GFAAS, ICP–MS 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 4 m have been 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 (of an estimated 1.6–2.5 million m³ contained) at a density of 1.0 g/cm³ and an average moisture content of around 40%. 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, an area beyond the scope of this paper. Another potential avenue of the exploitation of sewage sludges is discussed: that of the utilisation of sludges to extract contaminant metals from waste water and contaminated mine waters, which we demonstrate on pure aqueous synthetic samples. This paper presents a study of the exploitation of an historic sludge resource for its contained Au and residue post-metal extraction.  相似文献   

Sewage Sludge Activated Carbon as an Adsorbent and Catalytic Support: Evaluation of Nitrate Removal and Suzuki-Miyaura Cross-Coupling     

Clarissa H. Rosa  Cristiane R. Schmitt  Cecilia S. Fonseca  João Henrique Z. dos Santos  Toni J. Lopes  Gilber R. Rosa 《洁净——土壤、空气、水》2023,51(1):2100399

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A groundwater quality survey of an unsewered,semi‐rural area     

L. W. Sinton 《新西兰海洋与淡水研究杂志》2013,47(3-4):317-326

A baseline groundwater quality survey of 120 household wells in an unsewered area at Yaldhurst, near Christchurch, was carried out between September and December, 1976. Ammonia‐N levels were below the detection limit (0.02 g m^‐3) in all samples. Nitrate‐N, conductivity, and chloride levels tended to vary according to well depth and location, being lower in the deeper wells and in wells located in an area of shallow, stony soils. Approximately 33% of the wells contained coliform bacteria, faecal coliform bacteria or faecal streptococci. A subset of 25 wells was sampled fortnightly from January to August 1977. From January to June, mean nitrate‐N and conductivity levels remained stable at approximately 1.5 g m^‐3 and 11.2 mS m^‐1 respectively. An increase in these levels to 3.3 g m^‐3 and 15.8 mS m^‐1 in July‐August corresponded with a rise in the water table. Leaching losses from soils probably accounted for most of the nitrate entering the Yaldhurst aquifers, the contribution by septic tank systems being estimated at 20–30%. No direct evidence of contamination of the wells by septic tank effluent was found, although 23 of the 25 wells exhibited intermittent contamination by indicator bacteria throughout the 8 month sampling programme. Although a localised health hazard may exist, septic tank systems in the area were not considered likely to constitute a health threat to the confined aquifers underlying Christchurch city.  相似文献   

广东省入海排污口分类分布特征及监督管理措施研究     

唐俊逸  余香英  刘晋涛  张文博  蒋婧媛 《海洋科学》2021,45(3):51-58

本研究在广东省现有入海排污口清单的基础上,将入海排污口划分为4类,研究分析了入海排污口的数量、类型和分布情况.研究表明,广东省共有入海排污口1436个,东西两翼数量多于珠三角,区域和地市差异明显.结合广东省近岸海域环境质量状况和排污口分布特征,针对性提出了推进入海排污口规范化设置与备案、分类推进各类排污口污染治理,提升...  相似文献   

UASB和ABR在常温下处理生活污水的性能比较研究   总被引：1，自引：0，他引：1  

邓华健 《海洋技术学报》2010,29(1)

沿海城市生活污水的排放,对海洋环境有着重要影响。通过试验,在常温条件下研究了升流式厌氧污泥床反应器(Upflow Anaerobic Sludge Blanket Reactor,简称UASB)与厌氧折流板反应器(Anaerobic Baffled Reactor,简称ABR)处理生活废水的性能。试验结果表明:UASB与ABR对生活污水都有良好的处理效果,在HRT较长时,ABR反应器对COD和SS的去除效果优于UASB反应器;而当HRT缩短,小于12 h,UASB反应器内上升流速增加,改善了对COD的去除效果。ABR和UASB反应器对COD的去除效果都随温度的降低而降低。  相似文献   

珠江口磨刀门灯笼山断面枯季输沙关系分析     

康琮  宋志尧  孔俊 《海洋工程》2009,27(3):112-116

在分析磨刀门河口潮汐、水流、泥沙特性的基础上,结合2001年枯季口内灯笼山断面流量、输沙率同步实测过程线,对该断面的逐时输沙关系进行回归分析,发现无论涨潮阶段还是落潮阶段,其相关性均很高.同时通过单宽输沙量分解,对磨刀门悬沙输移主要因素进行分析,结果表明磨刀门在枯季期间以悬沙输移优势流贡献为主,悬沙向海输运.  相似文献   

海水冲厕技术研究与应用进展   总被引：1，自引：0，他引：1  

寇希元  张雨山  王静 《海岸工程》2009,28(2):83-89

推广海水冲厕是解决沿海城市淡水资源紧缺的有效措施之一。综述了近年来我国海水冲厕技术的研究现状和发展趋势，介绍了海水冲厕在香港的应用现状和在青岛等内地沿海城市的推广应用情况。总结并探讨了海水冲厕推广应用存在的问题及解决这些问题的应对措施。  相似文献