Bio-stimulation Approach in Bioremediation of Crude Oil Contaminated Soil Using Fish Waste and Goat Manure

Abstract

Aim: This study aimed to evaluate the ability of Fish waste and Goat manure to bio-stimulate the degradation process during bioremediation of crude oil-contaminated soil.
 Study Design: Research was designed to evaluate and compare the strength of the organic nutrients (Goat manure and fish waste) to stimulate the biodegradation of crude oil contaminated soil within 56 days.
 Place and Duration of Study: Study was carried out in Rivers State University Farm, Rivers state, Nigeria for 56 days from July to September 2018. Analyses were carried out weekly (per 7 days interval).
 Methodology: Eight (8) experimental set-up were employed, each having 5kg farm soil, all were left fallow for 6 days before contamination with crude oil on the 7th day in the respective percentages. Four of the set-ups were contaminated with 5% Crude oil while the other four were contaminated with 10% Crude oil. The contaminated plots were further allowed for 21 days for proper contamination and exposure to natural environmental factors to mimic a crude oil spill site before the application of bio stimulating agents (fish waste and goat manure). The set-ups of 5% Crude Oil Contaminated Soil (5% COCS) and 10% Crude Oil Contaminated Soil (10% COCS) were then stimulated with nutrient organics; Goat Manure (GM) and Fish Waste (FW) except two setups (one 5% COCS and the other 10% COCS) which were used as controls. The treatments (setups) were as follows: 5% COCS (control 1), 5% COCS + GM, 5% COCS + FW, 5% COCS + GM + FW and 10% COCS (Control 2), 10% COCS +GM, 10% COCS + FW, 10% COCS + GM + FW. Physiochemical and microbiological status of the soil before and after contamination was evaluated while parameters including Nitrate, Sulphate, Phosphate and Total Petroleum Hydrocarbon (TPH), as well as Microbial analyses, were monitored throughout the experimental period. Bioremediation efficiency was estimated from percentage (%) reduction of Total Petroleum Hydrocarbon (TPH) from day 1 to the residual concentration at day 56 of bio-stimulation setups with the control. The bio-stimulating potentials of goat manure and fish waste were compared using statistical tools.
 Results: The results revealed decrease in TPH with increasing time. The Amount (mg/kg) and Percentage (%) of Total Petroleum Hydrocarbon (TPH) remediated within the period of this study for 5% Crude Oil Contaminated Soil were as follows: 5% COCS-Ctrl 1 (563.52 mg/kg; 8.60%) < 5% COCS + GM (3608.84 mg/kg; 55.11%) < 5% COCS + FW (4156.49 mg/kg; 63.47%) < 5% COCS + GM + FW (4350.69 mg/kg; 66.44%) while 10% crude oil contaminated soil were: 10% COCS-Ctrl 2 (125.71 mg/kg; 1.21%) < 10% COCS + GM (4422.75 mg/kg; 42.82%) < 10%COCS + FW (5542.16 mg/kg; 53.66%) < 10% COCS + GM + FW (6168.66 mg/kg; 59.72%). This result shows that combination treatment with goat manure and fish wasteis more effective and has more bio-stimulating potentials than the single treatments. With respect to individual bio-stimulating agent, fish waste proves more effective and had a higher bioremediation efficiency than goat manure. The results of colonial counts obtained revealed that the total heterotrophic bacterial and total fungal counts generally increased during the study across the trend. The counts obtained from day 7 to 56 in the respective experimental set ups were as follows: Total Heterotrophic Bacteria counts increased from 6.32 to 8.20 Log10CFU/g (Control) < 6.32 to 9.05 Log10CFU/g (COCS+FW) < 6.41 to 9.13 Log10CFU/g (COCS+GM) < 6.32 to 9.58 Log10CFU/g (COCS+FW+GM). Similar progression was observed for total fungi, hydrocarbon utilizing bacteria and hydrocarbon utilizing fungi in all the experimental set ups although irregular differences were observed in the control set ups.
 Conclusion: The combination of organic nutrient such as goat manure and fish waste as bio-stimulating agents have shown to have higher percentage (%) bioremediation efficiency than when applied singly. It was also observed that the microbial biomass increased with time; moreover the nutrient monitoring analysis revealed a continuous gradual increase of the soil nutrient as bioremediation increases with time. The nutrient inherent in the bio-stimulating agents’ fish waste and goat manure resulted in increased soil nutrient (from day 7 to 56) as bioremediation period increase thereby enhancing soil nutrients at end of experiment. It is therefore recommended that bio-stimulating agents such as fish waste and goat manure should be employed in bioremediation of crude oil-contaminated soil especially due to its soil nutrient enhancement after bioremediation exercise. It’s a very good nutrient amendment option.

Remediation: A Novel Approach for Reducing Environmental Pollution

“…Bioaugmentation has been successfully applied to various types of contaminants, including heavy metals such as lead, mercury, cadmium, arsenic, and chromium (Mawang et al, 2021); organic pollutants like pesticides; synthetic compounds such as polychlorinated biphenyls (PCBs); polyaromatic hydrocarbons (PAHs) and dioxins; persistent organic pollutants (POPs); ionizing radiation such as alpha particles or beta particles; radioactive materials like radon gas (Lourenço et al, 2018); microbiological agents such as bacteria or viruses that are responsible for causing diseases in humans or animals, etc. Biostimulation is a form of biological treatment that involves the modification of the environment to stimulate existing bacteria capable of bioremediation (Awari et al, 2020). Bacteria that are capable of bioremediation include, but are not limited to, "Acinetobacter calcoaceticus", "Aeromonas hydrophila", and "Chloroflexus aggregans".…”

Combined addition of plant litter altered remediating effects on petroleum‐contaminated soil in Northern Shaanxi, China

“…The exploitation of onshore petroleum has rapidly increased across the globe over the past few decades. Moreover, the leakage and misuse of production waste during the drilling, production, refining, and transportation of petroleum have caused serious and persistent contamination of soil oil producing regions, and the surrounding areas (Awari et al, 2020; Ergozhin et al, 2020; Z. Lin et al, 2021). Hence, how to efficiently remediate petroleum‐contaminated soil has become an issue worth exploring for the study of soil and environmental sciences.…”