Feasibility of Purple Nutsedge anchored in wood based charcoal for effective greywater treatment

This paper explores the suitability of a novel, simple, inexpensive and effective macrophyte-based system to treat the greywater (GW). Purple Nutsedge (Cyperus rotundus) anchored in a layer of charcoal chunks derived from dry branches of Santa Rosa plum tree was employed as a bioagent in the treatment of GW. The performance of the system was studied over a 6-month period. Performance was assessed in terms of reduction in organic and inorganic matter load. At a maximum hydraulic retention time of 8 h, the plant reduced biological oxygen demand (BOD5), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), total phosphorous (P) and settleable solids (SS) to the extent of 74.7%, 67.8%, 28.8%, 22.2% and 94.1% respectively. The system met the Indian standards for discharge of treated GW onto the land for irrigation. The treated GW was successfully used to irrigate the Collard which is a loose-leafed vegetable of Brassica oleracea species popularly known as Haakh or Saagh locally. The system has demonstrated its potential for inexpensive, simple and effective treatment of GW.