Remediation Potentials of Wheat-Bran and Wood-Chips on Effluent Contaminated Soils From Paint Industries in Aba, Abia State Nigeria

Abstract

The remediation potentials of wheat bran and wood chips as Bulking-agents on paint effluent-Polluted Soils was evaluated. Different concentrations of bulking agents (10%, 30%, and 50%) were introduced into soils polluted with effluents and the physicochemical and microbiological properties of the soils were monitored for a period of 24 weeks. The Mean Heterotrophic Count (THC) of the Bacterial and fungal Isolates from the Paint effluents indicates that the effluents from sample F showed the highest bacterial count of 6.66±2.51 x 104cfu/ml, while sample B exhibited the least bacterial counts of 1.7±2.00x104 cfu/ml. Sample B showed the highest fungal count of 7.5±0.21 x104 cfu/ml while sample E showed the least count of 5.7±12.10x104 cfu/ml. The microorganisms isolated from the paint industry effluents include species of Staphylococcus, Klebsiella, Bacillus, Rhizobium, Pseudomonas, Salmonella, Mucor, Aspergillus niger, Fusarium, Aspergillus niger, Penicillium funiculosum and Geotrichum. Bacterial and fungal counts shows wood chips contain of 3.20x104cfu/g and 1.58x104cfu/g respectively while Wheat bran contains 3.47x104cfu/g and 1.77x104cfu/grespectively. Fungal isolates from the bulking agents include Saccharomyces cerevisiae, Rhodotorula species, Rhizopus species, Aspergillus niger, Aspergillus flavus and Penicillum notatum. The Bacterial and fungal counts of the paint-effluent polluted soil mixed with bulking agents over a 6-month remediation period increased progressively from the 1st week to the week 8, after which there was a decline from week 9 down. The polluted soil without amendment presented a slight increase in microbial growth. Higher microbial growth rates were manifested by the 50% amended option, followed by 30%, 10% and then the control. The Total Heterotrophic Bacteria isolated from the polluted soil amended with bulking agents include Pseudomonas putida, Serratia spp., Flavobacterium spp., Micrococcus spp., Bacillus spp., Klebsiella spp. and Arthrobacter spp. The Mean Physicochemical properties of the paint-effluent polluted soil mixed with bulking agents over the 24 weeks remediation reveals the pH ranges from 6.60±0.10 to 7.54±0.09 for the paint effluent polluted soil amended with a combination of the bulking agents. The concentrations of zinc, total nitrogen, total organic carbon and electrical conductivity levels had significant statistical difference across the samples through the period of remediation at p< 0.05. Germination test reveals growth of the bean seeds (Vicia faba) after 6 days of planting but significantly in the 50% treatment samples. The study however, demonstrates that paint effluent polluted soils treated with combination of bulking agents mainly at 50% amendment concentration reduces the toxicity of pollutants and increase the percentage of germination.