Potentials of water hyacinth compost in the remediation of palm oil mill impacted environment

Abstract

Water hyacinth (Eichhornia crassipes), an invasive aquatic plant, has garnered significant attention for its potential application in environmental remediation due to its high nutrient content and ability to bioaccumulate pollutants. The aim of the study was to evaluate the potentials of water hyacinth compost in the remediation of palm oil mill impacted environment. Soil and pond water contaminated with POME were obtained from palm oil mill location using standard method. Standard microbiological techniques were employed to enumerate, the microbial populations. The American Public Health Association (APHA) method was used to determine the physicochemical and heavy metal parameters. Water hyacinth was harvested manually from a stream and transported to the compost site where it was processed. The experimental set-up was designed into four sets consisting of the control (POME), POME and water hyacinth compost, POME contaminated soil and POME contaminated soil with the water hyacinth. The experiment was monitored for 56 days by checking the microbial growth and the changes in heavy metals. Results showed that the pH ranged from 5.2 to 7.3, electrical conductivity of in Day 1 ranged from 58.01 to 188.6 and 25.7 to 315.5µs/m in Day 56. The potassium concentration reduced from 94.02 in Day 1 to 38.23 mg/g. The copper concentration of POME treated with water hyacinth ranged from 9.55 to 0.00011 mg/g while the POME alone ranged from 2.1 to 1.5002mg/g. The POME contaminated soil with water hyacinth ranged from 6.03 to 0.00032 mg/g. The iron concentration of the sample ranged from 5.9-0.73 mg/g. The POME amended with water hyacinth had the least iron content in Day 56 followed by POME contaminated soil amended with water hyacinth. The Zinc concentration ranged from 2.14 to 4.78 mg/g in Day 1 and 0.026 to 3.7 in Day 56. Thus, POME and POME soil treated with water hyacinth had better reduction of the zinc metal than untreated samples. The range of Lead in Day 1 was 1.1803 to 4.3021 and 0.0023 to 3.786 mg/g in Day 56. This study underscores the dual benefits of water hyacinth composting as a remediation agent and waste-to-resource innovation, offering a sustainable approach to managing both invasive species and industrial pollution.