Studies of Wastewater Treatment Polishing Processes at the H-Coal Pilot Plant Site in Catlettsburg, Kentucky

摘要

A transportable wastewater treatment process development unit (PDU) sized for nominal flows of 60 mL/s (1 gpm) was designed and constructed at Oak Ridge National Laboratory (ORNL). The PDU, which contained individual modules for granular activated carbon adsorption, ozonation, and reverse osmosis processes, was used in polishing studies on wastewaters being discharged from the activated sludge clarifier in the wastewater treatment system on the site of the H-Coal direct liquefaction pilot plant. The processing modules were operated both individually and in various series configurations. The carbon adsorption unit contained three identical columns, each approximately 25 cm in diameter and 1.6 m in height. This unit was operated to obtain bed-depth-service-time data on the pseudocomponents of chemical oxygen demand (COD), total organic carbon (TOC), and color. The ozonation system contactor, which was approximately 25 cm in diameter and 1.6 m in height, was modeled as a stirred-tank reactor for the removal of these pseudocomponents. The reverse osmosis unit was operated at various recovery rates to study the rejection of key components and the behavior of spiral-wound cellulose acetate membranes. Results are presented for operations on wastewaters produced during the processing of both Illinois No. 6 bituminous and Wyodak subbituminous coals. Practical operating considerations encountered during these field tests are also reviewed. (ERA citation 08:040006)