4370233 Chemical detoxification of sewage sludge

techniques are used to separate the detoxified, acidic sludge and the acidic, heavymetal-containing water. The sludge may be neutralized for safe land application, and the metals can be recovered from the water using existing conventional techniques.

let stream of waste water with activated sludge, aerating the resulting mixture, separating the effluent water from the activated sludge to be recycled to the mixing step, passing the resulting excess sludge to a conversion stage, treating therein the cells of microorganisms composing suspended solids in said excess sludge to convert them to an organic liquid by a physical and/or physico-chemical means, passing the resulting organic liquid to a digesting stage n which activated sludge takes the organic liquid as a nutrient, aerobically digesting therein the organic liquid and discharging an effluent from the digesting stage.

4370091 REMOTE MANIPULATOR

ARM

George Gagliardi; assigned to Ateliers et Chantiers de Bretagne

4370233 -

CHEMICAL DETOXIFICATION OF SEWAGE SLUDGE

A remote manipulator arm interconnects a manipulator tool (13) to a support (1). The arm comprises three independent motorized arm components (7, 17 and 11). Conventional arm components are arranged for end-toend coupling with a fiied end coupling at one end and articulated coupling disposed in a fork (10) at the other end. The present invention provides at least one intermediate component (17) which further includes at least one fixed coupling (21) arranged at 90 degrees to its end coupling. Such a right-angled component provides greater flexibility in the design of a remote manipular arm assembled from such components.

Thomas Hayes; Randolph M. Kabrick; William Jewell; assigned to Cornell Research Foundation Inc.

A method is disclosed for the chemical detoxification of anaerobically digested organic sludge containing toxic heavy metals in insoluble form. A quantity of the sludge is transferred from a conventional anaerobic digester to an insulated reactor vessel where the sludge is mixed and aerated at a rate sufficient to raise the oxidation reduction potential of the sludge to above +3OO mv. and to maintain this condition for a period of 6-12 hours during which the heavy metals are converted to their desired oxidation state. The sludge is then acidified under controlled conditions to pH 1.0-3.0 for a period of 6-12 hours to solubilize the heavy metal. Conventional dewatering

4369115 MIXING WASTE WITH OXYGEN IN A WET OXIDATION PROCESS Gerald L. Bauer; Drug Inc.

assigned

to Sterling

A safe method for mixing pure oxygen, or an oxygen enriched gas, at high pressure, with waste liquor in a wet oxidation system, such that intermittent drying conditions are avoided, thereby preventing 345