Application of Bioaugmentation Technology to Improve the Activated Sludge Treatment Process in Removal of Aromatic Compounds

Abstract

<span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>This investigation was designed to evaluate the effects of bioaugmentation on</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>maintaining the system stability under shock loading conditions, standardizing the</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>effluent, and improving the sludge settlement. In this study, phenol was chosen as a</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>model of mono-aromatic compounds which are found commonly in many industrial</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>wastewaters, especially petroleum refineries and the petrochemical industry in Iran.</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>Impacts of bioaugmentation with the best isolated microorganism on the system</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>performance facing sudden toxic shock were investigated after acclimatizing the system</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>with phenol, isolating the phenol degrading microorganisms, and selecting the best</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>phenol degrading strain. Results indicated that this method was improved the efficiency</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>of the system under shock loading from 30% to 94% and SVI from 333 ml/g to 80 ml/g.</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>The effluent was standardized after bioaugmentation at a minimum HRTs of 10, 10, 12</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>and 24 h, respectively, and at influent COD of 800, 1000, 1500 and 2000 mg/l. The</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>system efficiency and SVI were located in an average range of 99.4-99.9% and 50-71</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>ml/g, respectively, and the sludge growth was good, even under high organic loading</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>rates after bioaugmentation. In conclusion, bioaugmentation could be used as an</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>effective and efficient method to improve a CAS process facing sudden toxic pollutant</em> <span style="font-size: 10pt; color: #000000; font-style: normal; font-variant: normal;"><em>shock loading.</em> </span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" /><br class="Apple-interchange-newline" /></span></span>