title: Real-time control of oxic phase using pH (mV)-time profile in swine wastewater treatment.
abstract: The feasibility of real-time control of the oxic phase using the pH (mV)-time profile in a sequencing batch reactor for swine wastewater treatment was evaluated, and the characteristics of the novel real-time control strategies were analyzed in two different concentrated wastewaters. The nitrogen break point (NBP) on the moving slope change (MSC) of the pH (mV) was designated as a real-time control point, and a pilot-scale sequencing batch reactor (18 m(3)) was designed to fulfill the objectives of the study. Successful real-time control using the developed control strategy was achieved despite the large variations in the influent strength and the loading rate per cycle. Indeed, complete and consistent removal of NH4-N (100% removal) was achieved. There was a strong positive correlation (r(2)=0.9789) between the loading rate and soluble total organic carbon (TOCs) removal, and a loading rate of 100 g/m(3)/cycle was found to be optimum for TOCs removal. Experimental data showed that the real-time control strategy using the MSC of the pH (mV)-time profile could be utilized successfully for the removal of nitrogen from swine wastewater. Furthermore, the pH (mV) was a more reliable real-time control parameter than the oxidation-reduction potential (ORP) for the control of the oxic phase. However, the nitrate knee point (NKP) appeared more consistently upon the completion of denitrification on the ORP-time profile than on the pH (mV)-time profile.
authors.affiliation: Department of Animal Life System, Kangwon National University, Hyoja 2, 192-1 Chunchon 200-701, South Korea.
authors.forename: C H
authors.initials: CH
authors.lastname: Ga
authors.forename: C S
authors.initials: CS
authors.lastname: Ra
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D019149:Bioreactors; D002244:Carbon / Q000737:chemistry / Q000302:isolation & purification; D004867:Equipment Design; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010865:Pilot Projects; D013552:Swine; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*
chemical_list: D014874:Water Pollutants, Chemical; D002244:Carbon