Sludge Composting

Tire chips are more nearly uniform than the most commonly used alternate material, wood chips, which results in more complete and odor-free composting. The initial cost of tire chips is about three times that of wood chips. Since tire chips don t degrade, however, they can be completely recycled whereas, about 25 to 35 percent of wood chips are lost to degradation with each batch. 

The primary disadvantage to using tire chips for sludge composting was the initial cost of the chips. Generally, no equipment modification is required. Tire chips cost about 60 to 80 per ton whereas wood chips are around 15 to 20 per ton. Another disadvantage is that any effect of dilution of contaminants in the sludge (particularly heavy metals such as lead and cadmium) by wood chips is lost (41). Since rubber does not decompose, none of it stays with the compost as wood chips do. Another concern that has been expressed is that zinc from the tires may somehow adversely affect the compost. It is not clear at this time whether these are valid environmental concerns. 

The Windsor facility no longer composts sewage sludge, so it is not using tire chips for this purpose. This technology has been considered in Columbus, Ohio Nashville, and several other U.S. communities. At this time, however, no facilities in the United States are known to use this technology on a routine basis. 

Tires may also be utilized for their energy value, as they have at least as high a Btu value as coal. This section describes the ways tires are being used for fuel in the United States. 

In the past three years there have been major increases in the utilization of waste tires as a fuel. Applications have included power plants, tire manufacturing facilities, cement kilns, and pulp and paper production. These applications have demonstrated the capability to extract energy value from the tires in an environmentally acceptable manner, while at the same time alleviating tire disposal problems in their communities. 

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Composting is another way to recycle nutrients and organic matter in sludge. The benefits from using sludge composts include increased water and nutrient holding... 

Determining the fate and movement of nutrients and metals in representative plant/soil systems amended with sewage sludge, composts, and other wastes... 

Moreno J.L., Hernandez T., Garcia C. Effect of a cadmium-contaminated sewage sludge compost on dynamics of organic matter and microbial activity in an arid soil. Bio Ferti Soils 1999 28 230-237. 

Secondary sources of PCDD/PCDFs, their reservoirs, are those matrices where they are already present, either in the environment or as products. Product reservoirs include PCP-treated wood, PCB-containing transformers and sewage sludge, compost and liquid manure, which can be used as fertilizers in agriculture and gardens. Reservoirs in the environment are, for example, landfills and waste dumps, contaminated soils (mainly from former chemical production or handling sites), and contaminated sediments (especially in harbours and rivers with industries discharging directly to the waterways). 

C86100 Sludge Compost Marketing and Distribution Regulatory Requirements in the United States... 

Solid sample FYM, sludge, compost. Industrial waste - reported by weight]... 

Nagaoka T, Umezu K, Kouno K, Yoshida S, Ishiguro Y, Ando T (1996) Selective Inhibitors of Legume Seeds in Activated Sludge Compost. Plant Growth Regul 20 295... 

Amir, S., Hafidi, M., Merlina, G., Hamdi, H., and Revel, J. C. (2004). Elemental analysis, FTIR, 13C-NMR of humic acids from sewage sludge composting. Agronomie 24,13-18. 

Garcia, C., Hernandez, T., and Costa, F. (1992a). Mineralization in a calcareous soil of a sewage sludge composted with different organic residues. Waste Manage. Res. 10, 445-452. 

Lightweight road construction material Playground gravel substitutes Sludge composting... 

Webber, M. D., and Bedford, J. A. (1996). Organic and metal contaminants in Canadian municipal sludges and a sludge compost Supplemental Report. 1996-RES-3, WTI, Burlington, Ontario. 

Ueno, Y., Haruta, S., Ishii, M., and Igarashi, Y. 2001. Microbial community in anaerobic hydrogen-producing microflora enriched from sludge compost. Appl. Microbiol. Biotechnol., 57,555-562. 

FIGURE 10.7 Effect of concentration of DOM derived from sludge (S) and sludge compost (P) on the Cu sorption onto the acidic (A) and calcareous (C) soils with initial Cu concentration of 40 mg/1. (From Zhou, L.X. and Wong, J.W.C., J. Environ. Qual., 30(3) 2001. With permission.)... 

Darmody, R.G. et al., Municipal sewage sludge compost-amended soils Some spatiotemporal treatment effects, J. Environ. Qual., 12, 231, 1983. 

Asbestos has been reported in municipal sewage sludges and sewage sludge composts Ifom large and small cities in the United States (Manos et al. 1991, 1993 Patel-Mandlik et al. 1988). Asbestos was detected in... 

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