Composting process

TABLE 25-65 Important Design Considerations for Aerobic-Composting Processes ... 

Moisture content should he in the range hetween 50 and 60 percent during the composting process. The optimum value appears to ne about 55 percent. 

If the process is properly conducted, it is possible to kill all the pathogens, weeds, and seeds during the composting process. To do this, the temperature must be maintained between 333 and. 344 K (140 and 160°F) for 24 h. 

In contrast, composting processes utilize a mixture of solids and yard waste under controlled environmental conditions to produce a disinfected, humus-like product. Three common composting systems are a horizontal agitated reactor, a horizontal nonagitated reactor, and an aerated static pile system (nonproprietary). Compost can be marketed as a soil conditioner in competition with such products as peat, soil, and mulch. Although a large potential market exists, significant effort is required to penetrate this market. Yard waste revenue of 6.50/m (S5/yd ) and product revenue of 2.00/m ( 1.50/yd ) appear to be reasonable market values based on various studies reported on the Web. 

Several researchers emphasized that compost is also an excellent material to use to prevent the acidification and the deterioration of soil productivity [8, 51-54]. Several factors including moisture content, temperature, aeration rate, and carbon to nitrogen ratio have direct influence on composting process, which has been reviewed in detail in the past. 

Table 7 Recent investigations on biodegradation of antibiotics in composting process... 

Mondini C, Famasier F, Sinicco T (2004) Enzymatic activity as a parameter for the characterization of the composting process. Soil Biol Biochem 36 1587-1594... 

Keywords Agronomic value of composting Anaerobic digestion Biowaste Compost quality Composting process Maturity... 

The most important technical methods of composting are statistic piles, windrows, and reactor vessels (shown in Figs. 12.3 and 12.4). Composting ingredients are mixed and during the composting process aeration is indicated. 

Bertoldi and Civilini (2006) carried out a composting process in two separate reactors first, only in the thermophilic phase, with the purpose of pathogen destruction and decomposition by selected thermophilic microorganisms second, only in the mesophilic phase, to perform the main microbial transformations with a higher... 

However, if the raw materials are contaminated or the composting process is incomplete, unfavorable effects must be expected. Heavy metals may be introduced into the compost with communal waste. To ensure that these do not enter the food chain, authorised limit values must be strictly adhered to. The same is true of organic contaminants (particularly polyaromatic or chlorinated hydrocarbons), the effect of which is extremely complex. If the fermentation process is not satisfactory, putrefaction will occur, the by-products of which (S02, NH3, N02, organic acids, cadaveric alkaloids, etc.) inhibit plant growth and attract pests. 

Hachicha S, Chtourou M, Medhioub K, Ammar E (2006) Compost of poultry manure and olive mill wastes as an alternative fertilizer. Agron Sustain Dev 26 135-142 Hansen RC, Mancl KM, Keener HM, Hoitink HAJ (1995) The composting process. Bulletin 792 of the Ohio State University, Columbus, OH... 

Streger K, Jarvis A, Vasara T, Romantschuk M, Sundh I (2007) Effects of differing temperature management on development of Actinobacteria during composting. Res Microbiol 158 617-624 The Composting Council of Canada the composting process - compost maturity. http //www. 

During the composting process much moisture is evaporated and a slight smell of ammonia is perceptible. After a successful spontaneous heating process has taken place, manure is obtained with a dry-matter content of at least 55%. This manure is suitable for transport and storage in the open air and can be easily applied by means of conventional manure spreaders. The minimum manure-storage requirement is not less than a 6 weeks capacity, a hardened floor and a roof. 

Improve odour control during composting process of air dried poultry manure. 

These are crumpled up before being added to the pile. Roughly equal volumes of kitchen waste and paper products are added as they become available. The composting process is slow, but requires no further attention. 

Keep it warm. The bottom layers of a pile are usually the first to decompose, generating heat that will rise through the pile and be lost from an unlidded bin or uncovered pile. The heat is valuable to the composting process, so use the lid, or cover the heap to keep it in. A cover will also conserve moisture, while keeping out the rain. You can add extra insulation by making a compost "comforter"—a thick plastic sack filled with fallen leaves. 

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