Biological sludge-energy recycling method

A method for converting organic cells and other substances in treated sludge into a readily metabolizable product comprising the steps of:

• adding to the sludge hydrolytic enzymes to hydrolyze the organic cells and other hydrolyzable substances in the sludge;
• rupturing the hydrolyzed cells after the step of adding to form a colloidal slurry including ruptured organic cell particles and to thereby release into the colloidal slurry endocellular enzymes present in the cells;
• holding the colloidal slurry for a sufficient length of time so that the hydrolytic enzymes and the endocellular enzymes further hydrolyze organic substances in the slurry and thereby form a readily dewaterable, substantially gel free microparticulate slurry;
• and thereafter dewatering the microparticulate slurry to form a moist product comprising microparticulate, organic substances.

A method for converting treated sludge into a readily metabolizable product comprising the steps of:

• contacting the sludge with hydrolytic enzymes to hydrolyze organic cells in the sludge and thereby to make them more susceptible to rupture when subjected to mechanical forces by adding to the sludge a substance capable of providing the sludge with hydrolytic enzymes;
• thereafter rupturing the cells in the sludge to form a colloidal slurry including ruptured organic cell particles, endocellular enzymes and gelled substances released by the cells during their rupture;
• holding at least one of the sludge, including the enzymes, and the slurry, including the particles;
• and thereafter separating the slurry into an effluent and a moist product.

A method for converting organic cells and other organic substances in treated sludge into a readily metabolizable product comprising the steps of:

• adding hydrolytic enzymes or hydrolytic enzyme producing microorganisms to the sludge and holding the sludge including enzymes for a sufficient length of time to hydrolyze the polysaccharide slime coating on the cells, to release into the sludge any heavy metal ions occluded in the coating, and to soften the walls of the cells;
• rupturing the cells in the sludge to form a colloidal slurry comprising ruptured cell particles, heavy metal ions endocellular enzymes released by the cells during their rupture and a gel;
• thereafter, autolyzing the colloidal slurry by holding it in a tank for a sufficient length of time to permit enzymes present in the colloidal slurry to hydrolyze the particles and the gel and form a microparticulate slurry including the ruptured cell particles;
• and thereafter dewatering the microparticulate slurry to form a substantially clear effluent and a moist product comprising the ruptured cell particles previously present in the microparticulate slurry.

A method for processing treated sludge including organic cells and heavy metals to recover therefrom usable materials comprising the steps of:

• adding to the sludge hydrolytic enzymes;
• holding the sludge and the added enzymes for a sufficient length of time to at least partially hydrolyze the walls of the cells and any polysaccharide slime coating present on the cells;
• thereafter rupturing the cells in the sludge to form a collodial slurry including ruptured cell particles and a gel and to thereby further release into the collodial slurry endocellular enzymes present in the cells;
• contacting the slurry with a metal chelating substrate to remove heavy metals therefrom;
• further hydrolyzing organic substances in the colloidal slurry by holding the slurry in a tank for sufficient length of time to hydrolyze the particles and the gel and to thereby form a microparticulate slurry;
• dewatering the microparticulate slurry and collecting a moist product;
• storing the product;
• preventing decomposition of the product by inhibiting microbial and pathogenic activity in the product being stored;
• and thereafter using the product as a readily metabolizable substance for living organisms.