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Current centralized sanitation systems adopted by many developed and developing countries minimize the exposure of wastewater to citizens by flushing them away from households. However, the transportation process consumes large amounts of energy and water and gives rise to diluted sewage. In contrast, decentralized sanitation systems that treat source separated wastewaters would encourage the recycling of nutrients for agriculture, reduce household water consumption significantly and generate a source of clean energy. This study is initiated by an attempt to redefine urban communities as renewable resource recovery centres through the adaptation of “decentralized and source-separationbased sanitation concepts.
Further Authors:
R. Rajinikanth - Nanyang Technological University, Singapore
Y. Mao - Nanyang Technological University, Singapore
I. Ho - Nanyang Technological University, Singapore
A. Ahamed - Nanyang Technological University, Singapore
J. Y. Wang - Nanyang Technological University, Singapore
In this concept, the wastes are separated into various streams. A source separation toilet would be used to separate urine and feces from the souce. Other waste streams include grey water (from showers and cleaning) and kitchen waste. Among the various household wastes, brown water and kitchen waste which are high in organic matter are suitable for energy recovery by anaerobic digestion. This study presented the potential of using brown water and kitchen waste as feed sources for energy production. Mesophilic anaerobic co-digestion of brown water with kitchen waste in benchscale (5 L) and lab-scale (30 L) reactors were carried out. The objective was to compare the performance between single-stage and two-phase systems, and between continuous stirred tank reactors (CSTR) and sequencing batch reactor (SeqBR) for the initial 110 days of operation. Monitoring parameters like reactor pH, COD, biogas volume and composition, VS, TS and VFA were analyzed twice a week. The kitchen waste/ brown water mixture was prepared daily and fed to the reactors in a semi continuous mode. All the reactors were operated in parallel and had an initial organic loading rate (OLR) of about 1 g COD/L.d. For the first 40 days of operation (i.e. OLR of 1 g COD/L.d), the effluent quality in terms of organic fraction was almost similar in all the configurations, with COD, TS and VS removal efficiencies of about 80, 55 and 65%, respectively. However, SeqBR was found to have higher organic removal efficiencies as compared to CSTR after the OLR increased to 2-3 g COD/L.d. Based on the bench-scale study, subsequent scaling up to 30 L lab-scale adopted the two-phase CSTR/ SeqBR digester configuration with similar operating conditions. During the initial 75 days of operation, the lab-scale two-phase CSTR/SeqBR digester showed better performance, as illustrated by the higher TS, VS, total COD and soluble COD removal efficiencies than the bench-scale reactors.
Copyright: | © European Compost Network ECN e.V. | |
Quelle: | Orbit 2012 (Juni 2012) | |
Seiten: | 7 | |
Preis inkl. MwSt.: | € 7,00 | |
Autor: | Jun Wei Lim | |
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Multi-component heat and mass transport model for composting process: Experimental validation
© European Compost Network ECN e.V. (6/2012)
Composting consists in an aerobic process where the organic matter from wastes is biodegraded and converted into a stable granular material called compost. Even if composting is considered to be based on natural phenomenon, it is governed by very complex mechanisms, involving many parameters such as quality and accessibility of the nutriments
for micro-organisms, local oxygen content, temperature of the medium, pH, moisture content, and so on (Mustin, 1987, Diaz et al., 2007;). These parameters directly affect biodegradation kinetics. Moreover, they are interdependent and impacted by the operating conditions, which make difficult the understanding of the process.
Microbial degradation of pesticides wastes in rustics devices type biobeds: The Biobacs
© European Compost Network ECN e.V. (6/2012)
Derived from the system of biological beds proposed by Swedish researchers, called biobeds, and from the Bayer Crop Science system called Phytobac®, or the biobac, is a tank insulated from the subsoil and filled with a mixture of organic and mineral materials. Thanks to the developed biological processes in them, the biobeds can provide simple and attractive solutions for the confinement and treatment of pesticide wastes. A biobac can last for up to 8 to 10 years. Despite the increasing interest shown for these rustic processes of bioremediation, limited data is available on their efficiency and monitoring. Biobacs specifications may vary with environmental conditions, waste volume and composition and pesticide concentration. The cost and availability of “carrier materials” and organic substrates used to support microbial activity must also be considered (biomixes). All these aspects need to be considered when improving biobeds efficiency.
Further Author:
J.C. Fournier - UMR Microbiologie et Géochimie des sols
Predicting the biochemical methane potential of organic waste by near infrared spectroscopy
© European Compost Network ECN e.V. (6/2012)
The biochemical methane potential (BMP) evaluates the ultimate amount of methane produced by any given waste orbiomass under anaerobic conditions. This value is currently one of the most important parameter for the design andcontrol of anaerobic digestion plants and more specifically in co-digestion plants where a broad rang of substrates canbe treated.
Further Authors:
J. Doublet, C. Laroche, A. Ponthieux, J. Cacho-Rivero - Veolia Environnement Research and Innovation
Effect of ammoniacal Nitrogen on methanogenic metabolic pathways during MSW anaerobic digestion
© European Compost Network ECN e.V. (6/2012)
Municipal solid waste (MSW) represents an important renewable energy sources and the sustainable management of organic wastes is a major environmental and economic issue. The anaerobic digestion of MSW, which occurs inlandfills and methanization treatment plants, is a very complex process. The final step of the waste degradation, i.e.methanogenesis, which produces methane, leads to the production of a biogas that could be transformed into heat,electric power and fuel gas (renewable energy). In order to produce more efficiently this renewable energy and toenhance the degradation of the organic fraction of waste, bioreactors landfill and methanization treatment plants are twopromising management strategies.
Further Authors:
J. Epissard - Irstea
M. Lemunier - Suez Environnement
DINplus – Neue Anforderungen an kompostierbare Bioabfallsammelbeutel und Konsequenzen für die Praxis
© Witzenhausen-Institut für Abfall, Umwelt und Energie GmbH (4/2023)
Viele Haushalte entsorgen weiterhin Teile ihrer Bioabfälle über die Restmülltonne, weil die separate Sammlung als unsauber empfunden wird. Als Lösung werden neben Papierbeuteln auch feuchtigkeitsresistente Kunststoffbeutel angeboten, die als „kompostierbar“ zertifiziert sind. Eine Reihe von Kommunen haben mit solchen Beuteln gute Erfahrungen gemacht, in vielen örE werden sie aber auch abgelehnt – es wird befürchtet, dass die Bürger sie mit herkömmlichen Kunststoffbeuteln verwechseln und in den Verwertungsanlagen der biologische Abbau zu lange dauert. Als Antwort auf diese Befürchtungen sind in der novellierten Bioabfallverordnung konkrete Regelungen formuliert worden. Nachfolgend werden aktuelle Entwicklungen zu diesem Thema beschrieben.