Method for treating wastewater sludge

专利名称：Method for treating wastewater sludge发明人：Jeffrey C. Burnham申请号：US07/621221申请日：19901130公开号：US05135664A公开日：19920804

摘要：A method for treating wastewater sludge which comprises the steps of furthertreating the sludges after they have been mixed with alkaline materials and are still in awet condition with carbon dioxide containing gases wherein the carbon dioxide is asignificant constituent for a time sufficient to reduce the pH below 10 and to prevent theemission of the ammonia nitrogen. Preferably heat is added to the mixture to acceleratethe reaction and facilitate drying. The product is useful as an agricultural product. In apreferred process, the amount of alkaline materials being sufficient to raise the pH ofthe mixture to 12 or above and to heat the mixture by an exothermic reaction to a rangeof about 52. degree. C. to about 62° C. and maintain the pH above 12 and the

temperature range for a minimum of 12 hours to reduce significantly offensive odor ofthe sludge to a level that is tolerable; to reduce anumal viruses therein to less than oneplaque forming unit per 5 grams dry weight of said sludge; to reduce pathogenic bacteriatherein no less than three colony forming units per 5 grams dry weight of said sludge; toreduce parasites therein to less than one viable egg per 5 grams dry weight of saidsludge; to retain a soil-like indigenous microflora; to reduce vector attraction to saidsludge; and to prevent significant regrowth of the pathogenic microorganism; andthereafter subjecting the mixture to carbon dioxide containing gas wherein carbon

dioxide is a significant constituent for a time sufficient to reduce the pH below 10 and toprevent the emission of the ammonia nitrogen.

申请人：N-VIRO ENERGY SYSTEMS LTD.

代理机构：Barnes, Kisselle, Raisch, Choate, Whittemore & Hulbert

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