Lena Trotochaud1,2, Rebecca M Andrus3, Kayana J Tyson1,4, Graham H Miller1,2, Claire M Welling1,2, Patrick E Donaghy5, Joseph D Incardona5, William A Evans5, Paul K Smith5, Tim L Oriard5, Ian D Norris5, Brian R Stoner1,2, Jeremy S Guest3, Brian T Hawkins1,2. 1. Duke University, Center for Water, Sanitation, Hygiene, and Infectious Disease (WaSH-AID), Durham, North Carolina 27701, United States. 2. Department of Electrical & Computer Engineering, Duke University, Durham, North Carolina 27708, United States. 3. Department of Civil & Environmental Engineering, University of Illinois at Urbana-Champagne, Urbana, Illinois 61801, United States. 4. Department of Civil & Environmental Engineering, Duke University, Durham, North Carolina 27708, United States. 5. Cascade Designs, Seattle, Washington 98134, United States.
Abstract
Providing safe and reliable sanitation services to the billions of people currently lacking them will require a multiplicity of approaches. Improving onsite wastewater treatment to standards enabling water reuse would reduce the need to transport waste and fresh water over long distances. Here, we describe a compact, automated system designed to treat the liquid fraction of blackwater for onsite water reuse that combines cross-flow ultrafiltration, activated carbon, and electrochemical oxidation. In laboratory testing, the system consistently produces effluent with 6 ≤ pH ≤ 9, total suspended solids (TSS) < 30 mg L-1, and chemical oxygen demand (COD) < 150 mg L-1. These effluent parameters were achieved across a wide range of values for influent TSS (61-820 mg L-1) and COD (384-1505 mg L-1), demonstrating a robust system for treating wastewater of varying strengths. A preliminary techno-economic analysis (TEA) was conducted to elucidate primary cost drivers and prioritize research and development pathways toward commercial feasibility. The ultrafiltration system is the primary cost driver, contributing to >50% of both the energy and maintenance costs. Several scenario parameters showed an outsized impact on costs relative to technology parameters. Specific technological improvements for future prototype development are discussed.
Providing safe and reliable sanitation services to the billions of people currently lacking them will require a multiplicity of approaches. Impn>roving onsite wasten>an class="Chemical">water treatment to standards enabling water reuse would reduce the need to transport waste and fresh water over long distances. Here, we describe a compact, automated system designed to treat the liquid fraction of blackwater for onsite water reuse that combines cross-flow ultrafiltration, activated carbon, and electrochemical oxidation. In laboratory testing, the system consistently produces effluent with 6 ≤ pH ≤ 9, total suspended solids (TSS) < 30 mg L-1, and chemical oxygen demand (COD) < 150 mg L-1. These effluent parameters were achieved across a wide range of values for influent TSS (61-820 mg L-1) and COD (384-1505 mg L-1), demonstrating a robust system for treating wastewater of varying strengths. A preliminary techno-economic analysis (TEA) was conducted to elucidate primary cost drivers and prioritize research and development pathways toward commercial feasibility. The ultrafiltration system is the primary cost driver, contributing to >50% of both the energy and maintenance costs. Several scenario parameters showed an outsized impact on costs relative to technology parameters. Specific technological improvements for future prototype development are discussed.
Entities:
Keywords:
ISO 30500; blackwater; electrochemical disinfection; granular activated carbon (GAC); nonsewered sanitation system (NSSS); onsite wastewater treatment system (OWTS); techno-economic analysis; ultrafiltration