Utilization of Wastewater from The Tapioca Starch Factory for Growing Napier Grass in Saline Soil

Abstract

The study of the utilization of wastewater from the tapioca starch factory for growing Napier grass in saline soil and effects on chemical properties of soil. The experiment was divided into 2 phases as following: The first phase, the researcher planned 7 solutions of RCBD experiments for 3 times each, for example, using the wastewater before treating in stabilization pond, using the wastewater before treating in stabilization pond together with irrigation water for 1:1 and 1:2, using the wastewater after treating in stabilization pond, using the wastewater after treating in stabilization pond together with irrigation water for 1:1 and 1:2, and non-using the wastewater as control. As the results of every experiment, they effected on the grass growth at 4 weeks including the numbers of clumps, grass per clumps, leaves per grass, and grass height. They were non-significant (p > 0.05). The second phase, the researcher planned 2 solutions of Paired T-test experiments for 3 times each, for example, using the wastewater before treating in stabilization pond, and non-using the wastewater as control plot. The results of both experiments revealed that they were effected on the grass growth and productivity at 12 weeks with non-significant (p > 0.05). The productivity of 3-month grass from the wastewater plot in term of wet and dried basis had average weighted 183.33 and 54.04 grams per leaves, 423.33 and 81.54 grams per trunks. The data from the control plot had average weighted 150.00 and 46.33 grams per leaves, 336.67 and 64.57 grams per trunks. In terms of soil properties before and after the experiments, both had significant of Potential of Hydrogen ion (pH), Electric Conductivity (EC), Total Kjeldahl Nitrogen (TKN), and Phosphorus (P) at (p < 0.05) except Potassium (K). It had non- significant at (p > 0.05) which found that the nutrients in soil- TKN, P-were reduced. Moreover, the amount of EC was also decreased which effected on saline soil except pH. It was higher. However, watering plants with wastewater helps Napier grass growth in terms of the amount of clumps, grass per clumps, leaves per grass, and grass height, together with the wet and dried weight of Napier grass with non-significant (p > 0.05) comparing with irrigation water. As the result, wastewater can grow Napier grass and boost the productivity which reuses the waste product directly. Moreover, it can reduce the budget for treating in stabilization pond including reducing using the irrigation water which is one way to reserve water resources.