Wastewater reuse through aquaculture in Hanoi : status and prospects | |
| Author | Vo Quy Hoan |
| Call Number | AIT Thesis no.AE-96-26 |
| Subject(s) | Aquaculture--Vietnam--Hanoi Water reuse--Vietnam--Hanoi |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science |
| Publisher | Asian Institute of Technology |
| Abstract | As only preliminary and/or incomplete descriptions existed on the development and potential of wastewater reuse through aquaculture which has been practised in Hanoi since the early 1960's, a field study was carried out to describe its historical development and to evaluate the current . status and prospects of wastewater-fed aquaculture production in Thanh Tri District, the main wastewater reuse area of Hanoi city. Wastewater was collected in Hanoi by the sewerage system through which both wastewater and stormwater were discharged without treatment to four rivers. Wastewater-fed aquaculture has been developed mainly by the farmers through experience accummulated over the past 30 years in ponds and rice fields through which the wastewater was pumped. Wastewater-fed aquaculture has passed through three stages of development: early development, formation of co-operatives, and dissolution of co-operatives, according to socio-economic changes in the country. Four farming systems: fish-only, rice-fish culture, fish seed and vegetables were practised in the wastewater-fed production area. In the fish "grow-out" systems, a polyculture of Mozambique tilapia (Oreochromis mossambicus) and Nile tilapia (O. niloticus), two Indian major carps (rohu, Labia rohita and mrigal, Cirrhinus mrigala), and Chinese silver carp (Hypophthalmichthys molitrix), was practised in wastewater-fed earthen ponds. While tilapia had precocious, uncontrollable breeding, slow growth rates and subsequent small size at harvest, rohu and mrigal were the most popular species in farmed areas both with and without a wastewater supply. In wastewater-fed fish ponds, fish yields ranged from 4.7 tonnes/ha in rice fish culture to 5.6 tonnes/ha in fish-only culture during the 10 months growing season. Privatisation of land use right has made it difficult to supply wastewater supply to fishponds with a decrease in the area of wastewater-fed aquaculture. Even though the systems were highly efficiency economically and had positive sociological impact because of higher gross margins and job opportunities than the rice-only production system. Further studies and development of the systems should focus 'on the importance and effectiveness of wastewater-fed fishpond systems in terms of wastewater treatment and the possibilities of technical improvements of wastewater reuse through aquaculture. |
| Year | 1996 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Edwards, Peter; |
| Examination Committee(s) | Demaine, Harvey;Hambrey, John; |
| Scholarship Donor(s) | Swedish International Development Cooperation Agency; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1996 |