摘要:

ABSTRACTAnexisting aetated lagoon treating piggery waste was converted into an aerobic sequencing batch reactor (SBR). After the commissioning period, the SBR plant treated piggery wastewater containing BOD and suspended solids (SS) concentrations of 2881 mg/l and 1419 mg/1 respectively, producing an effluent having an average BOD and SS of 18.7 mg/1 and 12.3 mg/1 respectively. The volumetric loadings on the SBR and the process were similar. However, the SBR process operated at a lower mixed liquor suspended solids (MLSS) concentration and shorter sludge retention period. Although the capital and operating costs of the SBR are higher than for the aerated lagoon, the simplicity of operation, the high BOD and SS removal efficiency, and the small land requirement make this type of process an attractive treatment option, particularly in places where land supply is limited and expensive.

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1989.tb01368.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTIron is not normally consideredto be a constituent of health significance, and recommended limits for iron in drinking water supplies are based on aesthetic considerations. Experience in Malawi has demonstrated that, even when present in only trace amounts, iron can influence the consumer's acceptance of an improved borehole supply. The effect of the use of plastic construction materials on the iron content of village groundwater supplies was investigated using a statistical approach. The majority of groundwater points using only plastic materials was found to supply water containing less than the WHO guideline value of 0.3 mg/l iron. In contrast, the use of ferrous‐materials increased the iron content of the water to unacceptable levels, sometimes causing the consumers to reject the borehole as a source of drinking water.Bacteriological data show that the quality of the alternative, traditional supply is far inferior to the new improved supply. An otherwise perfectly safe supply may therefore be abandoned as a direct result of contamination introduced by ‘down the hole’ components. This frustrates efforts to improve the well‐being of rural communities, and is a waste of precious development re

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1989.tb01369.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTThe historical developmentof the New Zealand rural water supply concept is described, and the basic principles are explained in terms of both its design features and reliance upon community involvement during the promotional, constructional and operational phases.Conceptional and cost comparisons are made between the New Zealand rural water supply concept and its urban counterpart, and an analysis is undertaken of the transferability of the concept to a developing world situation with the consequent emphasis on low‐cost construction and self‐help operation.The adoption of the New Zealand model is advocated as a potential design concept for a range of defined circumstances in developing countr

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1989.tb01370.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1989.tb01371.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Book Review in This Article:Field Hydrogeology, by R. Brassington.Troubled Water: Rivers, Politics and Pollution, by D. Kinnersley.Estimating Probabilities of Extreme Floods ‐ Methods and Recommended Research, by the National Research Counci

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1989.tb01372.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY