WHAT ARE THE BEST AND MOST SUSTAINABLE DEWATERING PROCESSES

The handling and reuse/disposal of biosolids is an increasingly costly portion of the wastewater treatment plant (WWTP) operation. Therefore, choosing the best and most sustainable WWTP biosolids dewatering systems should include economic accountability, process efficiency, and reduction of energy, polymer, operational labor, and overall operation and maintenance costs for dewatering processes.The manuscript will focus on the evaluation of the following dewatering alternatives: 1) screw presses, 2) belt filter presses, 3) centrifuges, and 4) hydraulic piston presses. The latest enhancements for centrifuges that have reduce energy consumption will be reviewed.Numerous approaches are available to increase the dewatered cake solids concentration from any type of dewatering equipment that have been proven and successful at WWTPs. A discussion of factors that impact dewaterability and suggestions for possible use to improve dewatering performance is included in the manuscript.Non-monetary advantages and disadvantages of the dewatering alternatives along with case histories of the automation of equipment to optimize performance and to be more sustainable by reducing polymer consumption and energy consumption are included.