As environmental legislation has become stricter in recent years, the issue of wastewater treatment in
rural areas has become an increasing concern. Choice of the most suitable on-site purification systems is
based on the key issues of affordability and appropriateness in Chinese rural areas. This paper describes an
integrated household constructed wetland (IHCW) system planted with willow (Salix babylonica) to treat
household domestic wastewater in rural villages in northern China. The precast frame structure of IHCW
is strong and waterproof. It can be mass-produced and installed per a standard set of specifications. The
IHCW has achieved high overall removal efficiencies for BOD5, TSS, NH4-N, and TP: 96.0%, 97.0%, 88.4%
and 87.8%, respectively. A 0.4m biomass layer cover on the system provided significant system thermal
insulation, maintaining high treatment performance in freezing winter conditions. The system is cost
effective and does not need any operational energy inputs, demonstrating its feasibility for single-family
use in developing countries.