EFFECTIVENESS OF AFRICAN LOCUST BEAN WASTEWATER AS A RESOURCE FOR PRESERVING AGRICULTURAL PRODUCE (GRAIN AS A CASE STUDY)

Abstract

The use of synthetic chemicals for increasing shelf life of agricultural produces have been widely reported to have hazard effect to human health if not kill. This study investigated the re-use of locust bean effluents as a resource for preserving produces as alternative to synthetic chemicals. Physicochemical properties of Jimba-Oja and NCAM effluent locations were determined, bioassay was also performed on maize weevils to evaluate lethal concentration of effluents within 15 and 25 minutes duration of exposure. Data obtained and observed were subjected to descriptive statistics. Physicochemical parameters of effluents showed that pH was slightly acidic 5.94 - 6.54. Dissolved oxygen ranged from 2.59 - 3.02 mg/L, Biochemical oxygen demand from 0.33 - 0.40 mg/L, Total hardness from 471.82 - 542.34mg/L of NCAM and Jimba-Oja effluent respectively. Concentration of cadmium, copper, nickel, cobalt, iron, Sulphate, phosphate and nitrate ranged from 0.15 - 0.24, 5.19 - 7.31, 0.12 - 0.33, 0.35 - 0.52, 46.94 - 57.18, 3.15 - 3.71, 87.32 - 96.57 and 2.19 - 2.47mg/L respectively. Lead concentration of 0.38mg/L was detected with NCAM effluent only. Toxicity evaluation showed that the mortality rate increased with increased in effluents concentration with respect to exposure time. Mortality rate of 2.2, 17.8 and 31.1% were recorded for Jimba-Oja effluent at concentration of 5, 10 and 15mL within 15 minutes of exposure while 11.1, 33.3 and 55.6% were recorded within 25 minutes. Mortality rate of 6.7, 31.1 and 46.7% were recorded within 15 minute while 17.8, 48.9 and 71.1% were recorded within 25 minute for NCAM effluent of the same effluent concentration. The study concluded that locust bean effluent as wastewater can be re-used as biopesticide.