Monitoring Physicochemical Parameters During Bioremediation of Hydrocarbon-Contaminated Soils in Brazzaville, Congo | Chapter 6 | New Horizons of Science, Technology and Culture Vol. 6

 

 

The biodegradation of hydrocarbons by bacteria is undeniably one of the most successful processes in the elimination of hydrocarbon pollutants. Several bacteria have already been used in numerous applications in the bioremediation of environments polluted by hydrocarbons. However, few bioremediation studies have been carried out with indigenous Bacillus genus strains obtained in Congo-Brazzaville. This study aimed to treat soils polluted by hydrocarbons using the bioremediation technique. Soil samples were taken from four (04) garages chosen in some districts of Brazzaville, namely Ouenzé, Mfilou, Djiri and Talangai. Four treatments were carried out for bioremediation treatment while monitoring physicochemical parameters by bioaugmentation, biostimulation and a mixture of bioaugmentation and biostimulation. Several physicochemical parameters were monitored during the different treatments to understand the factors that could influence microbial metabolism during the degradation of total petroleum hydrocarbons in the soil. The total petroleum hydrocarbons (TPH) were extracted by Soxhlet during the treatments. The results obtained showed that the physicochemical parameters are optimal during organic degradation processes. The ranges of physicochemical parameters values are respectively between 23.3 and 28.4°C for temperature, between 38.6 and 5266.01µS/cm for conductivity, between 6.01 and 7.5 for pH, between 0 and 70% for the maximum water retention capacity, between 1 and 10% for humidity, between 0 and 88 mg/Kg for nitrogen and between 0 and 298.93 mg/Kg for potassium. The Total Petroleum Hydrocarbons (TPH) concentrations in polluted soils decreased significantly throughout the treatments, with a drop between 25% and 85%. The greatest drop (75%-85%) in hydrocarbon concentrations is observed for Bioaugmentation (Bacteria) and Biostimulation+Bioaugmentation (NPK+Bacteria) combination treatments. Thus, bioremediation by adding Bacillus genus bacteria would be an alternative way for the depollution of soils polluted by hydrocarbons. Future research should focus on optimising the bioremediation process by investigating a wider diversity of indigenous microbial strains from different ecological niches in Congo-Brazzaville with a focus on enhancing hydrocarbon degradation efficiency.

 

 

Author(s) Details

Kiele Molingo Mbemba
Université Marien Ngouabi, Unité de Chimie du Végétal et de la Vie, Faculté Des Sciences et Techniques, BP 69, Brazzaville, Congo.

 

Gabriel Judicael Okeni-Boba
Université Marien Ngouabi, Unité de Chimie du Végétal et de la Vie, Faculté Des Sciences et Techniques, BP 69, Brazzaville, Congo.

 

Jean Maurille Ouamba
Université Marien Ngouabi, Unité de Chimie du Végétal et de la Vie, Faculté Des Sciences et Techniques, BP 69, Brazzaville, Congo.

 

Please see the book here :- https://doi.org/10.9734/bpi/nhstc/v6/6749