Reuse of treated sewage effluent for cooling water make up: a feasibility study and a pilot plant study

Abstract

This investigation was aimed at developing an acceptable technology for using secondary effluent as cooling water makeup for inland manufacturing industry in Australia. Approximate economic evaluations were made for a number of pretreatment alternatives and for internal treatment with chemical conditioning agents. Internal treatment with biocide dosing appeared to be the most promising option. A portable pilot plant scale cooling tower/heat exchanger unit was constructed. The unit incorporated an on-line, differential pressure biofilm monitor together with automated control and data acquisition systems. The pilot plant was installed on site at a sewage treatment plant near Sydney. It was demonstrated that the use of TSE for cooling water makeup is technically feasible. The rate of biofilm growth observed using chlorinated secondary effluent directly from the sewage treatment plant as makeup water was similar to the rate of biofilm growth observed when potable water was used and supplementary chemical treatment was not introduced in either case. Excellent control of biofilm growth was observed in subsequent experiments when supplementary additions of simple chlorine or bromine chloride treatment systems were carried out. The pilot plant was operated successfully at 5 cycles of concentration without any other supplementary treatment being required.

Control of biological growth in recirculating cooling systems using treated secondary effluent as makeup water with monochloramine

“…Use of MWW as cooling water has been studied and implemented for some time. However, previous studies suggested blending freshwater with small proportion of secondary effluent or significant pre-treatment of secondary effluent prior to the addition to recirculating cooling systems (Osborn, 1970;Rebhun and Engel, 1988;Wijesinghe et al, 1996). Only recently has treated secondary effluent been considered a promising alternative as the sole makeup water source for recirculating cooling systems (Hsieh et al, 2010;Li et al, 2011a,b).…”

Membrane Capacitive Deionization for Cooling Water Intake Reduction in Thermal Power Plants: Lab to Pilot Scale Evaluation

“…The CaCO 3 hardness of surface water used for cooling depends highly on the geohydrology of the aquifer and can range from soft (<60 mg/L CaCO 3 ) to very hard (>180 mg/L CaCO 3 ). Previously explored strategies to improve water efficiency of wet cooling towers include feed pretreatment [8,9], use of alternative feed sources [10], circulation water conditioning and acidification [11] and blowdown recuperation [12][13][14].…”

Scaling Control for Heat Exchangers in Recirculating Cooling Systems Using Treated Municipal Wastewater

“…Use of treated MWW for power plant cooling has been in full-scale operation for several decades. − However, MWW is typically used in recirculating cooling systems as a fraction of the total makeup water and/or after significant additional treatment (e.g., Palo Verde Nuclear Generation Station, Maricopa, AZ) . Few studies have focused on the feasibility of using treated MWW as the dominant makeup water with or without additional treatment.…”