Real-time control of oxic phase using pH (mV)-time profile in swine wastewater treatment

• Published in: Journal of hazardous materials 2009-12, Vol.172 (1), p.61-67
• Main Authors: Ga, C.H., Ra, C.S.
• Format: Article
• Language: English
• Subjects: Animal Husbandry; Animals; Applied sciences; Biological and medical sciences; Bioreactors; Biotechnology; Carbon - chemistry; Carbon - isolation & purification; Chemical engineering; Equipment Design; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General purification processes; Humans; Hydrogen-Ion Concentration; Loading rate; Methods. Procedures. Technologies; Moving slope change (MSC); Others; Oxidation-Reduction; Oxidation–reduction potential (ORP); pH (mV); Pilot Projects; Pollution; Reactors; Real time; Real-time control; Sequencing; Strategy; Swine; Swine wastewater; Time Factors; Various methods and equipments; Waste Disposal, Fluid - methods; Waste water; Wastewaters; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - isolation & purification; Water Purification - methods; Water treatment and pollution
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2009.06.133

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 NH 4-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.