Kirk B. Hird

Date of Award


Document Type


Degree Name

Master of Science (MS)


Chemical Engineering


The feasibility of treating slagging gasifier wastewater by physical-chemical means was studied. Pretreatment and treatment flow schemes were developed by using batch and continuous tests. Results were based mainly on wastewater residual total organic carbon (TOC). A treatment facility was designed and economically evaluated.

It was found that slagging gasifier wastewater is treatable by physical-chemical means using activated carbon and chemical oxidation as the two principal treatment steps. A pretreatment scheme consisting of lime addition, ammonia stripping, and recarbonation-coagu- lation was found to sufficiently purify the raw gasifier liquor so that activated carbon adsorption and chemical oxidation could be applied as secondary and tertiary treatment.

Oxidants found to be ineffective were: chlorine, sodium hypochlorite, hydrogen peroxide, and potassium permanganate. Ozone and bromine chloride were determined to be capable of oxidizing gasifier wastewater although bromine chloride oxidation seems to be more economical.

LCK activated carbon, manufactured by Union Carbide, proved to be the preferred granular carbon for slagging gasifier liquor treatment.

A total capital investment of approximately $14,748,000 can be expected for a facility capable of purifying pretreated wastewater produced from a slagging gasification plant having a large enough3 gas output to produce 250 million standard ft^3/day of methane. Annual operating costs are estimated to be $7,413,000, i.e., $10.75 per 1000 gallons of pretreated liquor.