Invited Perspective: Sanitation Innovation Holds Promise but Must Consider Risks to Users

Brown, Joe

doi:10.1289/ehp10609

Cited by 5 publications

(3 citation statements)

References 20 publications

(19 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The deployment of the NEWgenerator in other contexts was simulated by varying assumptions of influent composition, influent loading, electricity grid characteristics, and other contextual factors (e.g., LPG price), but other locality-specific factors (e.g., anal cleansing practices) will also be important to consider if more absolute costs and life cycle GHG emissions are required in specific deployment contexts. The sustainability indicators considered in this study were costs (economic) and life cycle GHG emissions (environmental), but future sustainability analyses may also consider the broader sanitation social-ecological system (S-SES) that defines sanitation technology as one component of a larger human-environmental system; additional studies on these aspects are critical for sustained use of NSS technologies. ,− …”

Section: Resultsmentioning

confidence: 99%

Advancing the Economic and Environmental Sustainability of the NEWgenerator Nonsewered Sanitation System

Watabe

Lohman

et al. 2023

ACS Environ. Au

View full text Add to dashboard Cite

Achieving safely managed sanitation and resource recovery in areas that are rural, geographically challenged, or experiencing rapidly increasing population density may not be feasible with centralized facilities due to space requirements, site-specific concerns, and high costs of sewer installation. Nonsewered sanitation (NSS) systems have the potential to provide safely managed sanitation and achieve strict wastewater treatment standards. One such NSS treatment technology is the NEWgenerator, which includes an anaerobic membrane bioreactor (AnMBR), nutrient recovery via ion exchange, and electrochlorination. The system has been shown to achieve robust treatment of real waste for over 100 users, but the technology’s relative life cycle sustainability remains unclear. This study characterizes the financial viability and life cycle environmental impacts of the NEWgenerator and prioritizes opportunities to advance system sustainability through targeted improvements and deployment. The costs and greenhouse gas (GHG) emissions of the NEWgenerator (general case) leveraging grid electricity were 0.139 [0.113–0.168] USD cap–1 day–1 and 79.7 [55.0–112.3] kg CO2-equiv cap–1 year–1, respectively. A transition to photovoltaic-generated electricity would increase costs to 0.145 [0.118–0.181] USD cap–1 day–1 but decrease GHG emissions to 56.1 [33.8–86.2] kg CO2-equiv cap–1 year–1. The deployment location analysis demonstrated reduced median costs for deployment in China (−38%), India (−53%), Senegal (−31%), South Africa (−31%), and Uganda (−35%), but at comparable or increased GHG emissions (−2 to +16%). Targeted improvements revealed the relative change in median cost and GHG emissions to be −21 and −3% if loading is doubled (i.e., doubled users per unit), −30 and −12% with additional sludge drying, and +9 and −25% with the addition of a membrane contactor, respectively, with limited benefits (0–5% reductions) from an alternative photovoltaic battery, low-cost housing, or improved frontend operation. This research demonstrates that the NEWgenerator is a low-cost, low-emission NSS treatment technology with the potential for resource recovery to increase access to safe sanitation.

show abstract

Section: Resultsmentioning

confidence: 99%

Advancing the Economic and Environmental Sustainability of the NEWgenerator Nonsewered Sanitation System

Watabe

Lohman

et al. 2023

ACS Environ. Au

View full text Add to dashboard Cite

show abstract

“…The sustainability indicators considered in this study were costs (economic) and life cycle GHG emissions (environmental), but future sustainability analyses may also consider the broader sanitation social-ecological system (S-SES) that define sanitation technology as one component of a larger human-environmental system; 64 additional studies on these aspects are critical for sustained use of NSS technologies. [64][65][66][67][68][69] There are significant reductions in per capita cost which can be achieved by increasing the number of users without increasing the system's physical footprint, but the potential of this approach is heavily dependent on whether the system can maintain treatment performance at these higher loadings and would require further laboratory and field testing. Targeted improvements to components (lithium photovoltaic battery, lower cost housing), reduced sludge moisture content and frontend O&M ratio can provide significant cost rand GHG reduction when combined.…”

Section: Prioritizing Paths Forward For Technology Development and De...mentioning

confidence: 99%

Advancing the economic and environmental sustainability of the NEWgeneratorTM non-sewered sanitation system

Guest

Watabe

Lohman

et al. 2023

Preprint

View full text Add to dashboard Cite

Achieving safely managed sanitation and resource recovery in areas that are rural, geographically challenged, or experiencing rapidly increasing population density may not be feasible with centralized facilities due to space requirements, site-specific concerns, and high costs of sewer installation. Non-sewered sanitation (NSS) systems have the potential to provide safely managed sanitation and achieve strict wastewater treatment standards. One such NSS treatment (backend) technology is the NEWgeneratorTM, which includes an anaerobic membrane bioreactor (AnMBR), nutrient recovery via ion exchange, and electrochlorination. Although the system has been shown to achieve robust treatment of real waste streams for over 100 users, the technology’s relative life cycle sustainability across deployment locations remains unclear. This study characterizes the financial viability and life cycle environmental impacts of the NEWgeneratorTM and prioritizes opportunities to advance system sustainability through targeted improvements and deployment. The costs and greenhouse gas (GHG) emissions of the NEWgeneratorTM (general case) leveraging grid electricity were 0.139 [0.113 – 0.168] USD·cap-1·d-1 and 79.7 [55.0 – 112.3] kg CO2-eq·cap-1·yr-1, respectively. A transition to photovoltaic-generated electricity would increase costs to 0.145 [0.118 – 0.181] USD·cap-1·d-1 but decrease GHG emissions to 56.1 [33.8 – 86.2] kg CO2eq·cap-1·yr-1. The deployment location analysis demonstrated reduced median costs (relative to the general case) for deployment in China (-38%), India (-53%), Senegal (-31%), South Africa (-31%), and Uganda (-35%), but at comparable or increased GHG emissions (-2% to +16%). Examining targeted improvements revealed the relative change in median cost and GHG emissions to be -21% and -3% if loading is doubled (i.e., doubled users per unit), -30% and -12% with additional sludge drying, and +9% and -25% with the addition of a membrane contactor, respectively, with limited benefits (0-5% reductions) from an alternative photovoltaic battery, low-cost housing, or improved frontend operation. This research demonstrates the NEWgeneratorTM is a low-cost, low-emission NSS backend technology with the potential for resource recovery to increase access to safe sanitation.

show abstract

“…The development of thermal treatment systems has been accelerated through the Bill & Melinda Gates Foundation’s Reinvent the Toilet initiative. , Community-scale, non-sewered sanitation systems developed through this program have been coined Omni Processors (OPs). , From a technological standpoint, these community-scale fecal sludge management systems are marketed as optimized sludge treatment technologies leveraging thermal treatment to inactivate pathogens and recover energy from bodily waste . These systems are proposed to be equipped with remote monitoring and have limited requirements for on-site operators. − Additionally, design teams note that OPs can handle a variety of inputs (e.g., menstrual hygiene materials, municipal solid waste, and organic wastes), which can cause blockages in sewage collection systems and interfere with the performance of other fecal sludge management processes. , Undoubtedly, addressing sanitation goals through technology deployment should consider the critical challenges of stakeholder engagement and social acceptability; ,− nonetheless, costs, energy, and life cycle environmental impacts are three indicators that are potentially of urgent relevance to decision-makers.…”

Section: Introductionmentioning

confidence: 99%

Financial Viability and Environmental Sustainability of Fecal Sludge Treatment with Pyrolysis Omni Processors

Rowles

Morgan

et al. 2022

ACS Environ. Au

View full text Add to dashboard Cite

Omni Processors (OPs) are community-scale systems for nonsewered fecal sludge treatment. These systems have demonstrated their capacity to treat excreta from tens of thousands of people using thermal treatment processes (e.g., pyrolysis), but their relative sustainability is unclear. In this study, QSDsan (an open-source Python package) was used to characterize the financial viability and environmental implications of fecal sludge treatment via pyrolysis-based OP technology treating mixed and source-separated human excreta and to elucidate the key drivers of system sustainability. Overall, the daily per capita cost for the treatment of mixed excreta (pit latrines) via the OP was estimated to be 0.05 [0.03−0.08] USD•cap −1 •d −1 , while the treatment of source-separated excreta (from urine-diverting dry toilets) was estimated to have a per capita cost of 0.09 [0.08−0.14] USD•cap −1 • d −1 . Operation and maintenance of the OP is a critical driver of total per capita cost, whereas the contribution from capital cost of the OP is much lower because it is distributed over a relatively large number of users (i.e., 12,000 people) for the system lifetime (i.e., 20 yr). The total emissions from the source-separated scenario were estimated to be 11 [8.3−23] kg CO 2 eq•cap −1 •yr −1 , compared to 49 [28−77] kg CO 2 eq•cap −1 •yr −1 for mixed excreta. Both scenarios fall below the estimates of greenhouse gas (GHG) emissions for anaerobic treatment of fecal sludge collected from pit latrines. Source-separation also creates opportunities for resource recovery to offset costs through nutrient recovery and carbon sequestration with biochar production. For example, when carbon is valued at 150 USD•Mg −1 of CO 2 , the per capita cost of sanitation can be further reduced by 44 and 40% for the source-separated and mixed excreta scenarios, respectively. Overall, our results demonstrate that pyrolysis-based OP technology can provide low-cost, low-GHG fecal sludge treatment while reducing global sanitation gaps.

show abstract

Invited Perspective: Sanitation Innovation Holds Promise but Must Consider Risks to Users

Cited by 5 publications

References 20 publications

Advancing the Economic and Environmental Sustainability of the NEWgenerator Nonsewered Sanitation System

Advancing the Economic and Environmental Sustainability of the NEWgenerator Nonsewered Sanitation System

Advancing the economic and environmental sustainability of the NEWgeneratorTM non-sewered sanitation system

Financial Viability and Environmental Sustainability of Fecal Sludge Treatment with Pyrolysis Omni Processors

Contact Info

Product

Resources

About