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Green Smart Water and Sanitation System
Published in Pradeep Tomar, Gurjit Kaur, Green and Smart Technologies for Smart Cities, 2019
Priya Singh, Garima Singh, Gurjit Kaur
Co-composting is the purification process consisting of an aerobic degradation of organics, by using more than one feedstock, for example fecal sludge and organic solid waste. The feedstock containing fecal sludge has a large moisture and N (nitrogen content) content, whereas the biodegradable solid waste consists of high organic carbon. By merging these two key elements, the whole process of purification is optimized more efficiently. In general, there are two types of co-composting designs: open and in-vessel. In the open composting, the sludge and solid waste is piled into long heaps called windrows and generally left to decompose. These windrow piles are alternately turned to provide oxygen with each part having the same temperature. While in the in-vessel composting method, the requirements involve moisture, air contact and mechanical mixing. Due to the same reason, it is often not considered as a correct option for decentralized utilities. It requires careful planning for proper purification even though it is a simple process.
Biological Treatment of Waste Solids
Published in Charles R. Rhyner, Leander J. Schwartz, Robert B. Wenger, Mary G. Kohrell, Waste Management and Resource Recovery, 2017
Charles R. Rhyner, Leander J. Schwartz, Robert B. Wenger, Mary G. Kohrell
In closed composting, also called in-vessel composting, a closed reactor vessel is used. The biology of the composting process is the same as in the open process; however, this approach permits much greater control of the temperature, moisture, and aeration in the composting process, as well as the final compost quality. The control of these composting variables results in accelerated composting rates. An in-vessel system requires approximately 14 days for composting and 20 days for curing, as compared to at least 21 days and 30 days, respectively, for composting and curing in windrow or static pile systems. The confined composting and greater throughput requires less land area than an open system. Other advantages include better control of odor and dust. The primary disadvantage of in-vessel composting is that it is capital intensive and the operational and maintenance costs also tend to be high.
End-of-Pipe Treatment Techniques
Published in Guttila Yugantha Jayasinghe, Shehani Sharadha Maheepala, Prabuddhi Chathurika Wijekoon, Green Productivity and Cleaner Production, 2020
Guttila Yugantha Jayasinghe, Shehani Sharadha Maheepala, Prabuddhi Chathurika Wijekoon
In-vessel composting consists of a group of techniques that confine the composting process to a building, container, or vessel. The composting process is accelerated by forced aeration or the mechanical turning of the composting materials in an in-vessel system. Numerous in-vessel composting methods are available, with each method varying according to vessel combination, aeration devices, and turning mechanisms. When considering these methods, most use some aeration and turning technologies adapted from the windrow and aerated pile methods; they attempt to overcome their deficiencies while also exploiting their attributes.
Optimization of combined in-vessel composting process and chemical oxidation for remediation of bottom sludge of crude oil storage tanks
Published in Environmental Technology, 2018
Ali Koolivand, Kazem Naddafi, Ramin Nabizadeh, Reza Saeedi
Biodegradation is the primary mechanism for removal of petroleum hydrocarbons in the environment [7–9]. In this framework, composting process has been adopted as one of the best methods for the removal of petroleum contaminants. Low costs and simple design and operation are the main advantages of the process [10,11]. The ability of composting process in removal of petroleum hydrocarbons has been verified at laboratory or field scales [12]. In-vessel composting provides the opportunity to adjust the operating factors of the process to enhance microbial activity and contaminant removal [13]. On the other hand, bioavailability and degradation of complex aromatic compounds are the main limitations of composting process [14]. As a result of microbial metabolism, some toxic metabolites may be produced which can disturb biodegradation of petroleum hydrocarbons [15,16].
Measuring food waste and creating diversion opportunities at Canada’s Green UniversityTM
Published in Journal of Hunger & Environmental Nutrition, 2018
Jessy Rajan, Arthur L. Fredeen, Annie L. Booth, Michael Watson
Production of currently and potentially compostable food wastes from the 2 primary foodservices outlets on the Prince George campus of UNBC totalled 1.1 tonnes per week, of which only 60% is currently compostable and only 49% is actually composted (see Table 5). Total food waste estimates are likely conservative for a number of reasons. First, our audit did not include other food wastes arising from improper disposal of food wastes into the nonfood solid waste stream. For example, though green bin receptacles were and are distributed across the campus, they are mostly positioned in the central main-floor hubs of each campus building and therefore are not convenient to all campus community members. In a previous solid waste audit performed at UNBC in 2008,12 compostable food wastes were found to represent 22% of the general solid waste stream, totaling 169 kg per week. Though this information was acquired 8 years prior to the present study, neither staff nor student numbers have risen appreciably over that interval. Second, the inclusion of protein-rich liquid food wastes (e.g., many milk products, soups, and sauces) could potentially further improve the quality of the compost generated and reduce the burden and cost of landfilling and/or unwanted additions to the sewage system. Finally, the 2 UNBC residence buildings, housing as many as 522 students during the spring of 2015, would have generated much food waste. Each of the 72 suites in the 2 residence buildings has a shared kitchen, and in the 2014–2015 academic year, only new students to UNBC were required to purchase the meal plan for the cafeteria. Green bins are not currently located in the residence buildings due to the difficulty in collecting the wastes from these locations during the winter months. A food waste audit for the residences at UNBC was conducted in the fall of 2012 (A. L. Fredeen et al., unpublished) and found that combined they generated 147 kg per week of currently compostable vegetable and fruit food wastes (volunteer basis only). Though this is undoubtedly a highly conservative estimate, it represents a further 22% increase to the 661 kg per week of currently compostable food wastes generated by the campus foodservices outlets. In total, food waste audit information for UNBC suggests that a comprehensive and improved food waste composting system would have ample feedstock and end use to justify the investment, particularly if all food wastes could be composted. An environmental and economic analysis of an in-vessel composting system at Kean University in the United States demonstrates that such investments in comprehensive composting facilities can provide both net profits (e.g., through vegetable production) as well as net environmental gains.29