Laboratory Demonstration and Preliminary Techno-Economic Analysis of an Onsite Wastewater Treatment System

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.

为全球数十亿尚未获得安全可靠卫生服务的人群提供服务，需要采用多元的解决方案。将现场污水处理提升至可回用的标准，可减少长距离运输污水与淡水的需求。本研究设计了一套集成错流超滤（cross-flow ultrafiltration）、活性炭与电化学氧化工艺的紧凑型自动化系统，用于处理黑水（blackwater）的液相组分以实现现场水回用。实验室测试结果表明，该系统可稳定产出符合以下参数的出水：pH值介于6至9之间，总悬浮颗粒物（total suspended solids, TSS）<30 mg·L⁻¹，化学需氧量（chemical oxygen demand, COD）<150 mg·L⁻¹。该系统可在进水TSS（61~820 mg·L⁻¹）与COD（384~1505 mg·L⁻¹）跨度较大的工况下实现上述出水参数，证明该系统为可处理不同浓度废水的鲁棒系统。本研究开展了初步技术经济分析（techno-economic analysis, TEA），以明确主要成本驱动因素，并为面向商业化可行性的研发路径排序优先级。超滤系统为主要成本驱动因素，其能耗与维护成本占比均超过50%。相较于工艺参数，部分场景参数对成本的影响更为显著。本研究还讨论了未来原型机开发所需的具体工艺改进方向。