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In the framework of a program for environmental protection conducted by the German mountaineers' club (DAV) problems emerging from residual solids accumulating in on-site wastewater treatment plants of mountain refuges were investigated. To handle these problems in an ecologically and economically reasonable way two devices for solar-supported treatment of sludge and bio-solids have been developed. These units support gravity-filtration and evaporation of liquid sludge as well as thermal acceleration of composting processes. Two solar sludge dryers were installed and operated without external energy supply at alpine refuges treating primary and secondary sludge, respectively. Batch-filling during the season could increase load capacity and a total solids concentration of up to 40% could be achieved before discharge at the beginning of the next season. The promising results from the solar sludge dryer encouraged for the development of a solar composter. The period of temperature levels suitable for composting biosolids in mountain areas can be extended considerably by application of this technology -- measured temperature distribution indicated no freezing at all. [ABSTRACT FROM AUTHOR]

A critical objective for any wastewater reuse program is to close the gap between supply of and demand for water and to minimize health and environmental hazards. Thus, the effects of treated effluent on crops, soils and community health must be considered carefully. When applying wastewater to soil-plant systems, it is to be noted that the passage of water through the soil reduces considerably the number of microorganisms carried out by the reclaimed wastewater. Nevertheless, there is a need to study the real rate of organism decay subject to water quality, soil and vegetable characteristics, and irrigation method. The aim of this work is to determine the fate of the fecal coliforms, coliphages F+ and CN13, and helminth eggs survival during the application of reclaimed wastewater in a vineyard orchard near the Cityof Arad (Israel) via on surface and subsurface drip irrigation systems. Wastewater obtained from a stabilization pond, and soil samples were tested and an important decrease of microorganisms was reached inboth cases, with the better values obtained with the sub-surface drip irrigation system. [ABSTRACT FROM AUTHOR]

We studied anaerobic batch degradation of solid poultry slaughterhouse wastes with different initial waste and inoculum concentrations and waste-to-inoculum ratios and simulated the dynamics of the process with a new generation model. Our modelling results suggest that inhibited propionate degradation by long-chain fatty acids (LCFA) and inhibited hydrolysis by a high propionate concentration constituted the rate-limiting step in the waste degradation. Palmitate was the most abundant LCFA in the assays. Within 27 days of incubation, upto 0.55 to 0.67 m3 of methane (STP)/kg VS added was produced under the studied conditions. Lower waste-to-inoculum ratios exhibited a faster onset and rate of specific methane production. In all the assays, ammonification occurred within 3 to 6 days and accounted for 50 to 60% of total nitrogen. [ABSTRACT FROM AUTHOR]

One of the by-products of instant coffee production is a solid wastewith high organic content This waste is disposed of either by landfill sites or by burning as fuel. Both alternatives are considered economically and environmentally unsatisfactory due to the physico-chemical characteristics of the waste. This study investigates the applicability of the forced aeration composting process to a mixture of this coffee waste and agricultural wastes. Approximately 40 tons of waste was used to set up the static piles. Temperature was used as the mainparameter to enable control of the aeration rate. Other parameters used to monitor the process were humidity, pH and carbon/nitrogen ratio. The results obtained were satisfactory and the experiments lead tothe production of a high quality compost presenting a carbon/nitrogen ratio of the order of 13/1 to 15/1. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved. [ABSTRACT FROM AUTHOR]

Composting of separated pig manure (SPM) was studied to evaluate criteria indicating compost maturity and to determine the effect of composting on the fractionation of trace elements in SPM compost. Composting was performed in turn piles and the following parameters were measured in 10 samples during 122 days of composting: temperature, C/N ratio, ash content, metal contents, humic substance contents, and fractions (humic acid, fulvic acid, and nonhumic fractions - HA, FA, and NHF, respectively). A sequential extraction scheme was used to partition Cu, Mn, and Zn in SPM compost. The C/N ratio and ash content exhibited a typically high rate of change during the first 33 days and levelled off thereafter. The fresh SPM was enriched with Cu, Mn, and Zndue to feed additives. All metal concentrations increased approximately 2.6-fold in the final compost due to decomposition of organic matter. The HA content increased to a maximum at 80 days, representing the degree of humification and maturity of the compost. During the composting process, the major portions of Cu, Mn, and Zn were found in the organic, oxide, and carbonate fractions, respectively. Metal distributions in different chemical fractions were generally independent of composting age and, thus, respective total metal concentrations in the composts. (C) 1999 IAWQ Published by Elsevier Science. All rightsreserved. [ABSTRACT FROM AUTHOR]

This paper presents the preliminary results of a Life Cycle Assessment (LCA) study which aims to compare two different potable water pipematerials: ductile iron (DI) and medium density polyethylene (MDPE).Stages where environmental impacts may be reduced in the life cycle of these pipes have been highlighted. A takeback scheme between watercompanies and pipe suppliers has been identified as an environmentalimprovement to the current disposal stage of the pipe life cycle. Potential exists for dual-use or reuse of abandoned mains. [ABSTRACT FROM AUTHOR]