Process and apparatus for liquid sludge stabilization

A process for treatment of sludge such that the end product of the treatment can be spread by gravity flow comprising:

• (a) providing sludge having a solids content in a range in excess of 0% but less than 10% such that the sludge is a liquid at ambient temperature and pressure, and providing an additive, to a substantially closed reactor vessel, said additive being a caustic compound selected from the group consisting of calcium hydroxide, calcium oxide, calcium carbonate, soda ash, sodium hydroxide and potassium hydroxide, with said additive present in sufficient quantity to adjust the pH of the sludge mixture to a level greater than about 12;
• (b) mixing the sludge and additive into a sludge mixture to ensure said pH is greater than about 12;
• (c) maintaining the pH level at a level greater than about 12 for a predetermined period of time;
• (d) controlling the pressure in the reactor vessel relative to the ambient pressure, to facilitate control of the reaction;
• (e) maintaining the sludge mixture as a free-flowing liquid that is at least 90% liquid;
• and
• (f) discharging the sludge and additive mixture from the reactor vessel in a sufficiently liquid form such that it can be further handled by gravity flow.