1000 resultados para Retort Water


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Batch, column and field lysimeter studies have been conducted to evaluate the concept of codisposal of retort water with Rundle (Queensland, Australia) waste shales. The batch studies indicated that degradation of a significant proportion of the total organic load occurs if the mixture is seeded with soil or compost. These results are compared with those from laboratory column studies and from the field lysimeter at the Rundle site. G.c.-m.s. analysis of some of the eluants indicated that significant degradation of the base-neutral fraction occurs even if no soil seed is added, and that degradation of this fraction was higher under anaerobic conditions.

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Oil shale processing produces an aqueous wastewater stream known as retort water. The fate of the organic content of retort water from the Stuart oil shale project (Gladstone, Queensland) is examined in a proposed packed bed treatment system consisting of a 1:1 mixture of residual shale from the retorting process and mining overburden. The retort water had a neutral pH and an average unfiltered TOC of 2,900 mg l(-1). The inorganic composition of the retort water was dominated by NH4+. Only 40% of the total organic carbon (TOC) in the retort water was identifiable, and this was dominated by carboxylic acids. In addition to monitoring influent and effluent TOC concentrations, CO2 evolution was monitored on line by continuous measurements of headspace concentrations and air flow rates. The column was run for 64 days before it blocked and was dismantled for analysis. Over 98% of the TOC was removed from the retort water. Respirometry measurements were confounded by CO2 production from inorganic sources. Based on predictions with the chemical equilibrium package PHREEQE, approximately 15% of the total CO2 production arose from the reaction of NH4+ with carbonates. The balance of the CO2 production accounted for at least 80% of the carbon removed from the retort water. Direct measurements of solid organic carbon showed that approximately 20% of the influent carbon was held-up in the top 20cm of the column. Less than 20% of this held-up carbon was present as either biomass or as adsorbed species. Therefore, the column was ultimately blocked by either extracellular polymeric substances or by a sludge that had precipitated out of the retort water.

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Access to potable water is frequently said to be the defining world crisis of the twenty-first century. The argument is usually framed in terms of either direct environmental constraints or various totalistic views of how the political determines outcomes. There is little or no scope for the agency of practical politics. Both physical and human geographers tend to be dismissive of the possibilities of democratic politics ever resolving crises such as those of the geography of water provision, in part because of views of scientific expertise that devalue popular participation in decisions about technical matters such as water quality and distribution. Such dismissal also has much to do with a more generalized denigration of politics. Politics (the art of political deliberation, negotiation, and compromise) needs defending against its critics and many of its practitioners. Showing how politics is at work around the world in managing water problems and identifying the challenges that water problems pose for politics provides a retort to those who can only envisage inevitable destruction or a totalistic political panacea as the outcomes of the crisis of the century.