Evolution of Nitrogen Pollutants of Urban Wastewater Treated by Activated Sludge and Oxidation Channel in Tunisia
| Autor: | Nizar Yeddes, Malika Trabelsi Ayadi, Amel Jrad, Dhouha Tangour |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Open Journal of Water Pollution and Treatment. 2014:11-17 |
| ISSN: | 2374-6351 2374-6343 |
| DOI: | 10.15764/wpt.2014.02002 |
| Popis: | A comparative study on the removal of nitrogen pollution from urban wastewater was conducted simultaneously at two treatment plants: activated sludge (STEP1) and oxidation channel (STEP2). The results showed an intensification of nitrification reactions that removes more than 76% and 95% of ammonia nitrogen respectively for the STEP1 and STEP2. Whereas, treatment increased the rate of the oxidized form 10.80 mg/l for STEP1 and 17.75 mg/l for STEP2. The monitoring of the nitrification parameters: temperature, pH and the COD, showed that the COD influenced the nitrification reaction in the STEP1. The inadequate aeration in the STEP1 increased nitrate without providing a significant reduction of ammonia therefore, not conducive to nitrification. The high rate of nitrate of the STEP1 is explained by the high rate of total nitrogen, including organic nitrogen. The organic nitrogen was targeted of the heterotrophic bacteria which transformed by enzymatic hydrolysis into ammonia nitrogen. Once in water, the ammonia nitrogen stimulated the activity of the nitrifying bacteria. This will create a competition between the two kinds of the bacteria in the consumption of oxygen. To increase nitrification, the homogenization mixing was advocated with intensification and control of the ventilation time in aeration basins. |
| Databáze: | OpenAIRE |
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