PMC:4160552 / 5992-7172 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/4160552","sourcedb":"PMC","sourceid":"4160552","source_url":"https://www.ncbi.nlm.nih.gov/pmc/4160552","text":"Effect of hydraulic retention time on COD removal\nFigure 2 shows the diagram of COD removal efficiency versus different concentrations of TPH at two HRTs (18 \u0026 24 hr) for each reactor.\nFigure 2 COD removal efficiency at two HRTs of 18 and 24 hours versus ratios of TPH/COD molasses in (a) MBR and (b) RBC.\nAs shown in Figure 2 increasing the ratios of TPH/COD molasses has led to the reduction of COD removal efficiency in both reactors. This is resulted from the fact that increasing TPH/COD molasses makes microorganisms start to use oily hydrocarbons instead of nutrients produced by molasses.\nOn the other hand, in order to form bonds between water and oily pollutant molecules, some concentration of surfactant twin-80 was added to the system which helps the absorption of hydrocarbons by microorganisms.\nAs depicted in Figure 2 when the ratio of TPH/COD was greater than 0.6, the slope of the efficiency decrement was increased. This is due to inhibition caused by aromatics and hydrocarbons in oily wastewater. Furthermore, COD removal efficiency was increased for higher HRT. This is caused by the contact between nutrients and microorganisms for a longer retention time.","divisions":[{"label":"title","span":{"begin":0,"end":49}},{"label":"p","span":{"begin":50,"end":306}},{"label":"figure","span":{"begin":185,"end":306}},{"label":"label","span":{"begin":185,"end":193}},{"label":"caption","span":{"begin":194,"end":306}},{"label":"p","span":{"begin":194,"end":306}},{"label":"p","span":{"begin":307,"end":597}},{"label":"p","span":{"begin":598,"end":810}}],"tracks":[]}