Reuse of Wastewater from Cassava Industry for Napier Grass Production

抄録

Cassava industry plays an important socio-economic role in Thailand economy. The growth of the cassava processing industry has resulted in extensive water pollution, as it generates large amounts of wastewater with extremely high concentrations of organic pollutants from washing and extraction. The need for wastewater management from cassava processing was apparent and fit with green technology for reuse of wastewater for agriculture. Napier grass (Pennisetum purpueum), a perennial species, has become a priority source of biomass for alternative energy production in Thailand, as the National Energy Policy Council has raised the target of power production from Napier Grass to 3,000MW under the 10-year alternative energy development plan (2012-2021) for Thailand. This study aimed to investigate the feasibility of using Napier Grass cultivation from cassava industry wastewater. Wastewater quality (effluent and influent) from cassava industry and its impact on soil chemical properties were studied at a site in Kalasin province, northeast Thailand to observe the effects of different concentrations (0%, 25, 50%, 75% and 100%) on germination test and Napier Grass biomass production. The wastewater characteristics were: pH of 7.2, EC 4dSm^-1, BOD 119mgL^-1, COD 1070mgL^-1, TS 3230mg L^-1, TKN 207mg L^-1, TP 226mgL^-1 and water soluble K 1490mgL^-1. The soil exposed to wastewater gave higher EC, more organic matter accumulation, higher total N, and available P when compared to soil without being exposed to cassava wastewater. The results showed that the wastewater concentrations significantly increased the Napier grass biomass. Therefore, wastewater from cassava industry can be used in Napier grass production as an example of application of green technology.