Title: Techno-economic analysis of domestic wastewater treatment and reuse models for apartment-scale systems in An Giang Province, Vietnam
Authors: Do Hong An, Nguyen Manh Ha
Volume: 10
Issue: 7
Pages: 319-326
Publication Date: 2026/07/28
Abstract:
Wastewater provision in An Giang Province, in Vietnam's Mekong Delta, is uneven. The centralised plants in Long Xuyen City run at only about 40.6% of their combined 30,000 m³/day design capacity, while peri-urban areas have almost no collection network at all. Apartment buildings must therefore treat their own wastewater, and the cost falls on residents. This study compares three apartment-scale alternatives on both technical and economic grounds: a moving bed biofilm reactor (MBBR), a membrane bioreactor (MBR), and a baffled septic tank coupled with a constructed wetland (BASTAF-CW). A greywater module built from locally available materials - coconut fibre, crushed concrete waste, and coconut shell activated carbon - is assessed as a supplementary component. All three are designed for the same standardised scenario: 200 households at 77 m³/day. A 20-year life cycle cost analysis (LCCA) at an 8% discount rate gives total costs of 4,674 million VND for MBBR (?8,300 VND/m³), 7,880 million VND for MBR (?14,000 VND/m³), and 2,056 million VND for BASTAF-CW (?3,700 VND/m³). The corresponding monthly operating charges per household are 133,000, 200,000, and 42,000 VND. The greywater module cuts influent load by 30-40% and lowers freshwater demand. The contribution of this study lies not in any individual technology, none of which is new, but in bringing technology comparison, life cycle cost, affordability, and locally sourced greywater reuse together into a single decision framework for An Giang under the new QCVN 14:2025/BTNMT regulation.