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An Investigation into the role of site and soil characteristics in onsite sewage treatment 总被引：1，自引：1，他引：0
The onsite treatment of sewage is common in all rural and regional areas of the world. Due to the public health and environmental risks that these treatment systems pose, the need for adopting performance-based management strategies is gaining increasing recognition. This demands the establishment of performance objectives for onsite sewage treatment and disposal which are based on stringent scientific analysis. A research project was undertaken to identify and investigate the role of influential site and soil characteristics in the treatment performance of subsurface effluent disposal areas. The treatment performances of a number of septic systems on a range of site and soil conditions were investigated together with detailed soil analysis. The changes to soil physico-chemical characteristics of the disposal area due to effluent application and its effluent renovation capacity were found to be directly related to the subsurface drainage characteristics. Significant changes to exchangeable cations and chemical parameters such as pH, electrical conductivity and cation exchange capacity (CEC) can result due to subsurface effluent application. A relationship exists between chemical parameters such as exchangeable Na and Ca:Mg ratio and CEC. A strong correlation also exists between the depth to the restrictive subsurface horizon and observed treatment performance. The study confirmed that soil chemistry can be a valuable predictive tool for evaluating the long-term performance of sewage effluent disposal systems particularly in poorly drained sites. 相似文献
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Biochemical fingerprinting (BF) databases of 524 enterococci and 571 Escherichia coli isolates and an antibiotic resistance analysis (ARA) database comprising of 380 E. coli isolates from four suspected sources (i.e. dogs, chickens, waterfowls, and human sewage) were developed to predict the sources of faecal pollution in a recreational coastal lake. Twenty water samples representing four sampling episodes were collected from five sites and the enterococci and E. coli population from each site were compared with those of the databases. The degree of similarity between bacterial populations was measured as population similarity (Sp) coefficient. Using the BF-database, bacterial populations of waterfowls showed the highest similarity with the water samples followed by a sewage treatment plant (STP). Higher population similarities were found between samples from STP and water samples especially at two sites (T2 and T3) which were located near the sewerage pipes collecting wastewater from the study area. When using the ARA-database, the highest similarity was found between E. coli populations from STP and water samples at sites T2 and T4. Both faecal indicators and as well as methods predicted human faecal pollution, possibly through leakage from submerged sewerage pipes. The results indicated that the Sp-analysis of faecal indicator bacterial populations from suspected sources and water samples can be used as a simple tool to predict the source(s) of faecal pollution in surface waters. 相似文献
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Steven?CarrollEmail author Ashantha?Goonetilleke Les?Dawes 《Environmental Geology》2004,46(2):195-208
Current methods of establishing suitable locations for onsite wastewater treatment systems (OWTS) are inadequate, particularly in light of the numerous cases of onsite system failure and the resulting adverse consequences. The development of a soil suitability framework for assessing soil suitability for OWTS allows a more practical means of assessment. The use of multivariate statistical analysis techniques, including Principal Component Analysis (PCA) and multi-criteria decision aids of PROMETHEE and GAIA, enabled the identification of suitable soils for effluent renovation. The outcome of the multivariate analysis, together with soil permeability and drainage characteristics permitted the establishment of a framework for assessing soil suitability based on three main soil functions: (1) the ability of the soil to provide suitable effluent renovation, (2) the permeability of the soil, and (3) the soils drainage characteristics. The developed framework was subsequently applied to the research area, Gold Coast, Queensland, Australia, and the use of standard scoring functions were utilised to provide a scoring system to signify which soils were more suitable for effluent renovation processes. From the assessment, it was found that Chromosol and Kurosol soils provided the highest level of effluent renovation, closely followed by Ferrosol and Dermosol, Kandosol and Rudosol soil types. Tennosol and Podosol soil types were found to have a significantly lower suitability, with Hydrosol soils proving the least suitable for renovating effluent from OWTS. 相似文献
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The quality of stormwater runoff from seaports can be an important source of pollution to the marine environment. Currently, little knowledge exists with regards to the pollutant generation capacity specific to seaports as they do not necessarily compare well with conventional urban land use. The research project focussed on the assessment of pollutant build-up and wash-off. The study was undertaken using rainfall simulation and small impervious plots for different port land uses with the results obtained compared to typical urban land uses.The study outcomes confirmed that the Port land uses exhibit comparatively lower pollutant concentrations. However, the pollutant characteristics varied across different land uses. Hence, the provision of stereotypical water quality improvement measures could be of limited value. Particle size <150 μm was predominant in suspended solids. Therefore, if suspended solids are targeted as the surrogate parameter for water quality improvement, this particle size range needs to be removed. 相似文献
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