Effects of Temperature and Calciums on the Treatment of Organics and Nutrient in Swine Wastewater Using an Integrated Bioelectrochemical Ion-Exchange System

Abstract

IntroductionSince husbandry industry has intensively developed, a great amount of high-strength swine wastewater has been generated. Even though several investigators have developed various processes for the treatment of swine wastewater, it was continuously required to develop more stable process high-strength wastewater. The objective of this paper was to investigate simultaneous removal of organic matter and nutrient in swine wastewater using an ion-exchange membrane system. Materials and MethodsThe ion-exchange membrane system consisted of three chamber (A, B and C) was separated by a cationic exchange membrane and an anionic exchange membrane(Figure 1). Ammonium ion in swine wastewater was ion-exchanged between a chamber A and a chamber B via a CEM. The ammonium ion was biologically oxidized to nitrate in a chamber B and nitrate was transported via an AEM and denitrified in a chamber C. Organic matter in the influent was acidified in a chamber A and used as electron donor for denitrification in a chamber C. COD, ammonia and phosphate used in this study were 9080.4 mg/L, 1910.6 mg/L and 43.2 mg/L. Results and DiscussionMaximum COD and ammonia removal efficiencies were 86.4% and 78.4%. Average COD and ammonia removal were 77.1% and 63.6% in Figure 2. When temperature sharply decreased to 13oC, the ammonia removal efficiency maintained about 42.0% due to the high ammonium flux (1.54 mg N/m2/sec) and MLVSS ratio (0.83) in Figure 2. As shown in Figure 3, the maximum phosphate removal efficiency was 91.0% (Ave.: 59.7%), and the phosphate removal was highly correlated with calcium consumption. This shows that phosphorus can be removed as a Ca3(PO4)2 or the coprecipitation of phosphate with calcite. Figure 1