Final report for the Water Foundation Project wastewater purification and reuse: mineral-based adsorbents for contaminant removal

[摘要] The safeguarding of existing water resources and investigation of alternatives to potable water supplies are critical to ensure long-term sustainability of water resources in south-west Western Australia. In addition, effective removal of nutrients from human-impacted natural waters is a necessary requirement for effective environmental management. Similarly, removal of contaminants from industrial, agricultural and domestic wastewater is pivotal to efficient water re-use. South-west Western Australia in particular currently faces a significant challenge in the management of its water resources. This area, while experiencing Australia’s highest rates of climate change, long-term population growth and associated development, has also seen a substantial decrease in winter rainfall since 1975. This decline in rainfall has resulted in increased competition for water resources between the growing urban population and requirements for environmental flows. In addition, declining groundwater levels present the possibility of oxidation of previously saturated, sulfide-rich soils and the formation of widespread acidity and loss of arable land.The goal of the Western Australian Water Foundation project “Wastewater purification and re-use: Mineral-based sorbents for contaminant removal” (PWF 009-05) was to source and characterize a suite of abundant industrial by-products, principally from Western Australia, with the specific aim of identifying by-products fit for purpose for specific environmental applications. In particular, this Water Foundation study examined the potential use of largely unexploited mineral processing by-products in Western Australia as “designer” contaminant adsorbents. This research was underpinned by a wealth from waste strategy aligning the productive use of mineral-based by-products to treat water and wastewater previously untreated, discarded, or treated by less efficient or more costly means.Mining and industrial by-products, many of which are generated in south-west Western Australia or the adjacent Yilgarn region, may be particularly well-suited for the attenuation of nutrients, trace metals and acidity in agricultural, urban and industrial wastewater. Abundant, low-cost industrial, mining, and mineral processing by-products offer a potentially cost-effective treatment option for soil, water, or wastewater.After identification and procurement, basic characterisation of by-products included major and trace element geochemistry, mineralogy, radioactivity, geochemical modelling, and leachate chemistry and toxicity. These inherent properties and suitability of by-products were then classified prior to further evaluation in laboratory-based column trials or field trials. In Western Australia, use of by-products is currently considered on a case-to-case basis rather than regulated according to a common framework of established standards. Thus, an evaluation and regulatory/approval framework for currently stockpiled by-products, if established, would facilitate appropriate environmental application of by-products where a need and effective treatment could be demonstrated. Knowledge acquired from this research formed the basis for a draft protocol which has been adopted by a Western Australian government working group as a screening process for future assessment of by-products.A wide range of by-products or other potentially beneficial materials were assessed in laboratory column trials including neutralised used acid (NUA) from the heavy mineral processing industry, a steelmaking by-product, red mud and red sand from the alumina refining industry, activated carbon, calcined magnesia, attapulgite, zeolite, fly ash, laterite, water treatment residues, carbonate minerals and a range of rocks common in south-west Western Australia. Detailed physico-chemical assessment, extensive column trials and a multi-year field trial of NUA as a turf farm soil amendment showed that NUA, a steelmaking by-product, and calcined

[发布日期] 2010-10-14 [发布机构] CSIRO

[学科分类] 地球科学(综合)