Evaluation of Reed Bed Technology to Dewater Army Wastewater Treatment Plant Sludge.

摘要

As operator of over 100 small wastewater treatment plants (WWTPs), the Army has an interest in efficient and cost-effective sludge dewatering systems. Many Army wastewater treatment plants use conventional sand-drying beds to dewater sludge. However, sand drying involves costly regular removal of sludge, and sand-drying beds are vulnerable to operational problems with long drying periods during wet weather and sand media clogging. Successful new technologies for sludge treatment in small-scale WWTPs include wedgewater beds, vacuum-assisted beds, and reed-bed systems. This study builds on a previous USACERL evaluation of wedgewater and vacuum-assisted bed performance by compiling operational data from municipal and industrial WWTPs that have reed bed systems to evaluate their potential for Army use. The use of reeds speeds sludge dewatering because the root systems maintain natural drainage channels throughout the sludge volume, and because reeds complement air drying by drawing water into the plant for evapotranspiration. Reed beds were found to be easier to operate and maintain than sand-drying beds, and to virtually eliminate the need for regular sludge removal. Moreover, reed beds can be simply and efficiently retrofit to existing sand-drying beds. Because the Army has large-area drying beds that can be converted to reed beds economically, reed bed systems were found to have a good potential for use at Army WWTPS. Wastewater treatment plant, Sludge dewatering systems, Reed bed technology.