Occidental Chemical Corporation

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Stanley A Sojka

Robert L Irvine

Joseph F Colaruotolo

Vernon J Lloyd

Lloyd H Ketchum, Jr

Robert R Bonk

A process for removing nickel and phosphorus species from a spent electroless nickel plating solution is described. This process involves an initial precipitation of phosphite values from the plating solution, followed by oxidation of hypophosphite and remaining phosphite to phosphate values, and the final removal of phosphate and nickel by lime precipitation. The treated plating solution is then separated from the precipitants, such as by filtration, and preferbly contain less than 1 milligrams/liter of nickel and/or total phosphorus species. This process is a cost effective method for treating spent electroless nickel plating solutions which is readily adaptable for on-site use.

Treatment of electroless nickel plating baths

The invention relates to the treatment of chemical process wastewaters and chemical waste landfill leachates containing obnoxious and hazardous halogenated organic chemicals by the use of a combination of physical, chemical and biological processes to produce a liquid discharge acceptable to the environment in an efficient and economical manner.

Integrated biological-adsorption process for treating waste water

Combinations of physicochemical and biological treatment processes are capable of removing dioxins, polychlorobiphenyls (PCB's) and other halogenated organic compounds from wastewaters. The dioxins and PCB's are removed by at least 90 percent in the pretreatment steps of neutralization, oxidation, and sedimentation; the residual amounts are removed in a powdered activated carbon enhanced sequencing batch reactor (PAC-SBR) operating at a high mixed liquor suspended solids concentration (&gt;5000 mg/L). Powder activated carbon (PAC) is supplemented to the bioreactor to ensure complete removal of the dioxins (&lt;0.8 ppt) and PCB's (&lt;2 ppb). The PAC-SBR enhanced biological treatment process is capable of meeting stringent effluent limits on not only on dioxins and PCB's but also on other toxic halogenated organic compounds. The treatment cost of this process is substantially less than either the conventional granular activated carbon adsorption technology or two stage treatment of biodegradation and carbon absorption.

Removal of dioxins, PCB's and other halogenated organic compounds from

This invention relates to the treatment of obnoxious waste effluents, both industrial and municipal, such as chemical waste landfill leachates, chemical process wastewaters and other obnoxious waste effluents by the use of microbial cultures, especially adapted to biodegrade the obnoxious chemicals in the chemical wastes, such as activated sludge and inoculants for activated sludge, and the new inoculated activated sludges and their use in biological wastewater systems such as continuous and batch reactors.

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Grand Island, NY, United States of America

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