Sewerage sludge

Efforts in recent years have been directed toward the use of recycled material in reclamation. Sewage sludge has been used to add organic material to substitute top soil (Bhumbla, 1992 Logan, 1992). The bacterial content of sewerage sludge is usually not a problem, provided that grazing and human exposure at the site is delayed for several weeks or months after treatment. 

In pollution control in treatment of sewerage and sludge, removal of SOjc and NO from flue gases. 

Cake A Sludge from a combined sewerage system sewage treatment plant of a representative city in Japan. The cake was dewatered by vacuum filter after lime and ferric chloride were added to mixed primary and excess sludge. 

Cake D Sludge from separated sewerage system sewage treatment plant for domestic waste. The cake was dewatered by filter press after conventional (l80 - 200 °C) thermal conditioning of the mixed sludge. 

The numerical pretreatment standards listed in EPA s Clean Water Act (CWA) are a minimum requirement. The sewerage agency must make a case-by-case determination to ensure that (1) the POTWs permit hmits are not exceeded by the influent, (2) the water quality standards are not exceeded as a result of the discharge, (3) the toxic pollutants entering the POTW are adequately treated, and (4) the influent does not cause the POTW s sludge to exceed any applicable... 

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