ABSTRACT

An Innovative Technology for Recycled Industrial Wastewater Treatment

Industrial wastewater discharges are a major environmental problem. The current trend in industrial wastewater management focuses on pollution prevention both by source reduction/clean technologies and by closed water systems, in which water recycling plays a major role. Cooling water is often the major use in an industrial plant and it offers the most potential for recycle. Ultra-high lime with aluminum process (UHLA) is potential new technology for such applications. It is an innovative technology with excellent potential for improving industrial water use efficiency. It has the ability to remove most of the unwanted compounds that limit the extent of recycling. It combines the removal of sulfate with the removal of all scale forming materials. Furthermore, it shows promise as a technology for removing chloride from recycled industrial water in order to decrease corrosion. Development of UHLA technology offers the potential for a treatment option that is substantially less expensive than other alternatives such as reverse osmosis. The estimated cost for UHLA is about one third that for reverse osmosis. Using aluminum in waste alum sludge from water treatment plants as an aluminum source for the process will reduce the cost of the technology even more.  Furthermore, UHLA treatment is potentially applicable to other industrial water problems such as pretreatment of brine before evaporation/crystallization and pretreatment of brackish water before membrane demineralization.

A research program is being established to develop UHLA technology. This research is timely due to the trend toward more pollution prevention and resource conservation by wastewater minimization and efficient water use. The overall goal of the proposed research is to study chloride removal by UHLA process, evaluate different alternative aluminum sources, and develop a model for multicomponent removal by UHLA. To achieve this goal, four specific objectives are proposed: 1) Develop analytical and experimental procedures; 2) Develop basic information on chloride removal using UHLA process; 3) Evaluate effectiveness and cost of alternative aluminum sources; 4) Develop a model for UHLA process. These objectives will be pursed through laboratory experiments in three different reactor systems and through computer modeling. Equilibrium and kinetic coefficients and other parameters will be obtained and the data will be used to develop the predictive model of the technology.

Successful completion of this project will provide data that can be used to evaluate the potential of using UHLA in different applications such as recycled cooling water treatment, treatment of brines prior to evaporation/crystallization, and pretreatment before desalination in order to improve water recoveries and membrane life.