Sewage treatment : papers presented at the Fourth Conference on Sewage Treatment, Ames, Iowa, October 11, 12 and 13, 1922, May 14, 1923

The topics included in this bulletin include the relationship of the State Board of Health to Iowa sewage treatment plants, relationship of sewage disposal to water purification, sewage treatment and its relation to public health, methods of sewage disposal, the role of bacteria in sewage purification and the activated sludge process for sewage disposal

Application of municipal sewage sludge to agricultural land in Tennessee

As mankind has become more aware of the frailty of the environment on planet earth, issues dealing with the disposal of by-products created by mans\u27 existence are demanding more attention. The disposal of one type of by-product, municipal sewage sludge, was examined in this study. A questionnaire was mailed to 150 mechanical sewage treatment plants in Tennessee in order to document the extent and characteristics of sludge application to agricultural land by municipalities in Tennessee. The cost of sludge disposal by land application is compared to other methods of disposal. Also, factors that potentially limit land application from the perspective of municipalities are identified. Aided by data gathered from this survey and data gathered from a Tennessee Division of Water Pollution Control Survey, it was determined that over half of the municipalities in Tennessee apply a portion of their sludge to agricultural land. Based on information from both surveys, approximately AS.7% of the sludge generated in Tennessee during the 1986-88 period was applied to land. The survey indicated that a non-linear relationship existed between plant size and land application with less land application by very small and very large plants. Average N,P,K concentrations of sludge were 3.2-1.7-.5. It appeared that land application was more prevalent in East and Middle Tennessee than in West Tennessee. The disposal cost estimations derived from the survey varied over a wide range and future case study research should attempt to more carefully assess cost. However, results from this survey suggest, at least tentatively, that land application compares favorably with other methods of disposal, especially disposal by landfilling. Factors identified by sewage treatment plant managers that could potentially limit land application include cost, site availability, public relations, regulatory change, management inertia, and heavy metal accumulation. The potential for each of these limiting factors to affect treatment plants in general is difficult to predict because of the unique conditions relating to specific treatment plants. Addressing these potential limitations will play an important role in the increased or decreased use of land application of sewage sludge

Mechanical performance of concrete with partial replacement of sand by sewage sludge ash from incineration

"Advanced Materials Forum VI , vol. 730-732"The production of sewage sludge from waste water treatment plants is increasing all over the world. Disposal of sewage sludge ash is a serious environmental problem. If we think of the areas needed for sludge ash disposal, we clearly understand the importance of reusing sewage sludge ash in concrete. This paper presents results related to the replacement of sand by sewage sludge ash. The sludge was characterized for chemical composition (XRF analysis), crystalline phases (XRD analysis) and pozzolanic activity. The effects of incineration on crystal phases of dry sludge were investigated. Two (W/C) ratios (0.55 and 0.45) and three sludge percentages (5%, 10% and 20%) by cement mass were used. The mechanical performance of SSAC at different curing ages (3, 7, 28 and 90 days) was assessed by means of mechanical tests. Results show that sewage sludge ash leads to a reduction in density and mechanical strength. Results also show that concrete with 20% of sewage sludge ash and W/C=0.45 has a 28 day compressive strength of almost 30MPa

Mechanical performance of concrete with partial replacement of sand by sewage sludge ash

The production of sewage sludge from waste water treatment plants is increasing all over the world. Disposal of sewage sludge is a serious environmental problem. If we think of the areas needed for sludge ash disposal, we clearly understand the importance of reusing sewage sludge ash in concrete. This paper presents results related to the replacement of sand by sewage sludge ash. The sludge was characterized for chemical composition (XRF analysis), crystalline phases (XRD analysis) and pozzolanic activity. The effects of incineration on crystal phases of dry sludge were investigated. Two (W/C) ratios (0.55 and 0.45) and three sludge percentages (5%, 10% and 20%) by cement mass were used. The mechanical performance of SSAC at different curing ages (3, 7, 28 and 90 days) was assessed by means of mechanical tests. Results show that sewage sludge ash leads to a reduction in density and mechanical strength. Results also show that concrete with 20% of sewage sludge ash and W/C=0.45 has a 28 day compressive strength of almost 30MPa

Development of optimal location and design capacity of wastewater treatment plants for urban areas: a case study in Samawah city

Water, and related wastewater structures, are critical factors in the existence and the improvement of civilizations. Wastewater gathering and management has a considerable effect on the climate and economy at both regional and global level, and, accordingly, it is appropriate to advance actions that guarantee effective management for wastewater, particularly in urban areas. This research thus examined the environmental and economic aspects of proposed locations for wastewater treatment plants. Samawah city, located in the southern part of Iraq, was selected as a case study for the research methodology, and for research purposes, the studied city was divided into three main zones (1, 2, and 3) of sixteen areas. The Google Earth tool was used to calculate the lowest elevations in the studied zones in order to assess the suggested positions of treatment plants. Additionally, the WinQSB program was utilised to select the most appropriate positions for treatment plants based on data obtained from local government departments. These data include population, water consumption, and required lengths and subsequent cost of pipes. This research thus developed a new strategy for assigning the locations of wastewater treatment plants

Comparison of the co-gasification of sewage sludge and food wastes and cost-benefit analysis of gasification- and incineration-based waste treatment schemes

The compositions of food wastes and their co-gasification producer gas were compared with the existing data of sewage sludge. Results showed that food wastes are more favorable than sewage sludge for co-gasification based on residue generation and energy output. Two decentralized gasification-based schemes were proposed to dispose of the sewage sludge and food wastes in Singapore. Monte Carlo simulation-based cost-benefit analysis was conducted to compare the proposed schemes with the existing incineration-based scheme. It was found that the gasification-based schemes are financially superior to the incineration-based scheme based on the data of net present value (NPV), benefit-cost ratio (BCR), and internal rate of return (IRR). Sensitivity analysis was conducted to suggest effective measures to improve the economics of the schemes

Ohio Guide for Land Application of Sewage Sludge

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