TY - JOUR AU - Tran Kien AU - Huyen Dong AU - Thu Nguyen AU - Thang Nguyen PY - 2021/11/06 Y2 - 2024/03/29 TI - Application of material flow analysis (MFA) for estimating the potential of Nitrogen recirculation in closed-ecosystem based catfish farming JF - Science & Technology Development Journal: Science of the Earth & Environment JA - STDJSEE VL - 5 IS - SI1 SE - Original Research DO - https://doi.org/10.32508/stdjsee.v5iSI1.569 UR - http://stdjsee.scienceandtechnology.com.vn/index.php/stdjsee/article/view/569 AB - The purpose of this study is to evaluate and analyze the possibility of nitrogen recirculation when applying a closed eco-system for intensive catfish ponds in the Mekong Delta in accordance with the existing available natural conditions in the local area. A closed ecosystem is proposed for optimizing N emissions from intensive pangasius farming on the basis of closed flows of materials, waste, and energy. The entire system is applied to Tran Trung Nhan household in An Binh B ward, Hong Ngu city, Dong Thap province consisting of 6 sub-systems (catfish ponds, composting, rice cultivation, livestock, liquid fertilizer, aquatic ditches) which are designed to be interacted, and Nitrogen in the catfish ponds are used as the main nutrient sources throughout the integrated system. The material flow analysis (MFA) method, which is based on the principle of material flow balance, is applied in the integrated system to analyze the potential of Nitrogen circulation in the whole system. The results show that the input N source is mainly from feed (43.35 kgN), and there are 3 main sources of N emissions from the system: sewage sludge (20.55 KgN), wastewater (3.4 KgN), and hydrolyzed nitrogen from dead fish (3 KgN). The source of N generated from sewage sludge is mixed with other wastes (biomass from rice straw and water hyacinth) in the system to produce compost (26 KgN), and wastewater generated from catfish ponds after aquatic treatment is supplied to agricultural activities (4.9 KgN). ER -