Material flow analysis in an integrated catfish farming system in Mekong Delta, Vietnam: A case study

Abstract Wastewater and catfish pond sediment of catfish breeding in Mekong Delta Vietnam directly discharge into rivers or canals that is a cause of environmental problems. To solve this problem, the integrated catfish breeding was applied to reuse wastes from catfish pond as raw materials for other purposes. The method of material flow accounting (MFA) is used to assess the materials and wastes fluxes. The results show that wastewater form catfish pond can reuse for water morning glory and maize as water supply. Catfish pond sediment could make composting to supply for maize as organic fertilizer. Discharging wastewater into receiving canal was 74.1%, the rest is evaporated into the air (21.17%) and accumulated in the compost and biomass of cultivation plants (4.73%). The organic matters accumulated in cultivation plants and soil are 1.95% and 9.6% respectively, and the remaining amount is accumulated in the compost. Scaling up for 9 households have been assessed. The present research suggests that the integrated catfish system can reduce the discharging wastes into environment and prevents environmental pollution.