Sludge management in advanced biological wastewater treatment plants

The advanced biological wastewater treatment plants, which are constantly increasing in our country, treatment sludge has formed as a result of the phosphorus and carbon removal process. In plant with high equivalent population, wastewater pollution loads has increased and tons of sludge is produced every day. This has made it essential to identify the management that includes the reasonable assessment and disposal of sludge in advanced biological wastewater treatment plants. This study has created with the design values and 2017-2018 operational data of the Malatya Advanced Biological Wastewater Treatment Plant. The 2. stage transition of the treatment plant, where wastewater was treated at an average flow rate of 99.312 m3 / day and 73 tons / day of sludge containing % 20 KM between the years of 2018-2017, has examined. In the stage increase has been evaluated the future pollution load of the plant, sludge amounts of the preliminary and final settling, the effect of the sludge on biogas production, sludge drying and disposal options. It is calculated that the treatment plant capacity will increase to 850,000 equivalent population in the 2nd stage. The preliminary and secondary settling sludges has been stabilized in anaerobic digesters and the organic portion of the sludge was reduced. 75 tons / day of sludge, which contains 25% KM, will be produced in the sludge dewatering unit. Anaerobic digesters will be made and at least 30% of the energy consumption of the plant will be obtained from biogas. Sludge drying systems were evaluated according to the final disposal option. The most economical disposal method of stabilized sludge produced in the plant is landfill in the evaluation made on sustainable methods for Malatya province. However, this option was not considered suitable due to the limited storage land. Solar drying and agricultural use are suitable after anaerobic stabilization. Sludge, which reached ≥ 90% KM by thermal drying, has been evaluated thermal disposal.