Acetogenic Pretreatment of Textile Wastewater for Energy Conservation

Bangladesh has come a long way in transforming its prehistoric cottage industry into post-industrial textile mills. International retail houses, instilling sustainable practices in the textile mills has become the norm. Most commonly the textile wastewater undergoes chemical pretreatment before extended aerobic treatment, which is both resource and energy intensive. The paper proposes to replace the chemical pretreatment with anaerobic acetogenic pretreatment which would reduce the biological oxygen demand loading to the aeration basin and hence, the amount of required energy for aeration. A bench scale study using an existing wastewater treatment plant influent with anaerobic acetogenic pretreatment was effective in reducing biodegradable organic matter with an efficiency of 95 %. This meant a reduction of 143 kg BOD5/day loading prior to aerobic treatment would generate an energy savings of 572 kWh/day. This amount of energy savings is deemed significant in the context of Bangladesh with a per-capita power consumption of 7kWh/day.