Researcher(s)
- Methuli Ratnayake, Environmental Engineering, University of Delaware
Faculty Mentor(s)
- Daniel Cha, Civil, Construction, and Environmental Engineering, University of Delaware
Abstract
Wastewater treatment removes organic matter and suspended solids, but it also produces sludge that must be treated or disposed of. Instead of viewing this sludge only as waste, it could be possible to convert it into something useful, like fuel or oil. This project focused on developing an activated sludge system that could be used to treat wastewater and support future research on sludge resource recovery. Two identical wastewater treatment systems were assembled using tanks, pumps, aeration, mixing, settling, influent, and effluent components. OECD synthetic wastewater was prepared so the systems could be tested using a consistent and controlled wastewater source. The synthetic wastewater contained peptone, meat extract, urea, phosphate, and several mineral salts. The pumps were calibrated to provide the required flow rate and maintain a hydraulic retention time of approximately 12 hours.
Chemical oxygen demand, or COD, and total suspended solids, or TSS, were selected to evaluate the wastewater and sludge. The COD of the prepared synthetic wastewater was measured as 244 mg/L. The TSS method was also practiced using previously collected sludge. Fresh activated sludge was not available during the experimental period, so the treatment systems could not be fully operated and influent and effluent results could not be compared. Future work will add activated sludge to the systems and measure COD and TSS before and after treatment. These measurements will be used to evaluate the removal of organic matter and suspended solids. The sludge produced during treatment can then be collected and studied to determine whether it is suitable for conversion into recoverable oil products. This work provides the system setup and analytical methods needed for future wastewater treatment and sludge resource recovery experiments.