Recycling of aquaculture wastewater and sediment for sustainable corn and water spinach production
Authors: Tra Van Tung, Quoc Ba Tran, Nguyen Thi Phuong Thao, Le Quoc Vi, Tran Thi Hieu, Son Le, Nguyen Quang Tuan, Christian Sonne, Su Shiung Lam, Le Thanh Hai, Quyet Van Le
Abstract: This study develops a method to reuse aquaculture wastewater and sediment from a catfish pond in order to increase agricultural productivity and protect the environment. Material flow analysis (MFA) is a central concept of this study that involves collecting catfish pond wastewater (CPW) and reusing it to irrigate five water spinach (Ipomoea aquatic) ponds before discharging it into a river. Typically, catfish pond sediment (CPS) was collected and composted to produce organic fertilizer for cornfields. The results revealed that pollutant removal efficiency of wastewater from CPW (by using water spinach) were total organic carbon (TOC) ¼ 38.78%, nitrogen (N) ¼ 27.07%, phosphorous (P) ¼ 58.42%, and potassium (K) ¼ 28.64%. By adding 20 tons of CPS compost per hectare of the cornfield, the corn yield boosted 15% compared to the control field. In addition, the water spinach grew and developed well in the medium of wastewater from the fish pond. Altogether, the results illustrate that catfish pond wastewater and sediment can act as organic fertilizers for crops meanwhile reduce environmental pollution from its reuse.