Resource-Recycling System for Domestic Wastewater Treatment Using Biogeofilter Ditches Planted with Useful Plants
It is necessary to develop an energy-saving and resource-recycling system for water purification in rural and mountainous areas. This paper outlines the development of a resourcerecycling system for water purification. The purification system consisted of a combination of an anaerobic/aerobic treatment plant and biogeofilter (BGF) ditches filled with zeolite and Kanuma soil as bed filter materials. The BGF ditches were planted with useful aquatic and terrestrial plants. The average rates of total nitrogen (T-N) and total phosphorus (T-P) removal by the aquatic plants were 1.34 g m-2 d-1 and 0.34 g m-2 d-1, respectively. The water purification system decreased the average T-N concentration to 0.31 mg L-1 and average T-P concentration to 0.22 mg L-1 from domestic wastewater in summer. The useful plants planted in the BGF ditches grew vigorously and were more productive indicating that the secondary effluent of the domestic wastewater contains essential nutrient elements. Thus, the use of this effluent for water culture of useful plants enables to purify the domestic wastewater and is also an effective means of nutrient recycling.