Occurrence of Toxic Substances Inhibiting the Nitrification in Waste Water from Industrial Zones in Vietnam
Main Article Content
Abstract
Abstract: By using a mobile laboratory with toxicity as a key parameter, the occurrence of toxic wastewater in two Vietnamese industrial zones and one factory was investigated. During this measurement campaign in two industrial zones a monitoring of the centralized wastewater treatment plants (WWTP) and the sewage systems of the industrial zones was carried out. Furthermore, the influent and effluent of a chemical WWTP at the company Groz-Beckert was investigated, to assess the removal of heavy metals by the chemical treatment.
The toxicity screening showed that nitrification inhibiting substances occurred in the two investigated industrial zones. A centralized WWTP in a North Vietnamese industrial zone Nam Sach showed toxicities up to 60% in the wastewater treatment plant’s effluent. These toxic substances inhibited the biological degradation of organic pollutants by the activated sludge bacteria for three days. The online toxicity monitoring of the centralized WWTP in the Hoa Cam industrial zone inCentral Vietnamshowed shock dosing of nitrification inhibiting substances in effluent with toxicities up to 50%. The toxicity monitoring of the chemical WWTP at the factory of company Groz-Beckert proved that the heavy metal removal was done successfully, these results were confirmed with ICP measurements.
Keywords: Monitoring, toxicity, nitrification inhibition, industrial wastewater, online measurements.
References
[2] Jönsson K., Grunditz C., Dalhammar G.,La Cour Jansen J. (2000), "Occurrence of nitrification inhibition in Swedish municipal wastewaters", Water Research 34(9), pp. 2455-2462.
[3] Jönsson K., Magnusson P., Jönsson L.-E., Göran Hellström B.,Jansen J. l. C. (1996), "Identifying and fighting inhibition of nitrification at Öresundsverket", Water Science and Technology 33(12), pp. 29-38.
[4] Laursen K. D., Jansen J. C. (1995), "Are 50% of the Danish wastewater treatment plants inhibited?", Stadsog Havneingenioren 2, pp. 41-43.
[5] Grau P.,Da-Rin B. P. (1997), "Management of toxicity effects in a large wastewater treatment plant", Water Science and Technology 36(2–3), pp. 1-8.
[6] Rudolph K., Dong P. H., Dung H. V., Friedrichs F., Genthe W., Long N. V., Meinardi D.,Trung D. Q. (2015), "Abwasser-Monitoring in Echtzeit mit Toxizitäts-Screening zur technischen und wirtschaftlichen Optimierung von Abwassersystemen", KA - Korrespondenz Abwasser, Abfall 6 pp. 520 - 528.
[7] ISO 8192 (2007), "Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation".
[8] OECD 209 (1993), "Test No. 209: Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation)", OECD Publishing.
[9] Çeçen F., Semerci N.,Geyik A. G. (2010), "Inhibitory effects of Cu, Zn, Ni and Co on nitrification and relevance of speciation", Journal of Chemical Technology & Biotechnology 85(4), pp. 520-528.
[10] Hufschmid A., Becker-Van Slooten K., Strawczynski A., Vioget P., Parra S., Peringer P.,Pulgarin C. (2003), "BOD5 measurements of water presenting inhibitory Cu2+. Implications in using of BOD to evaluate biodegradability of industrial wastewaters", Chemosphere 50(1), pp. 171-6.