Soil microbial response to waste potassium silicate drilling fluid

Area of Science:

• Environmental Science
• Soil Microbiology
• Waste Management

Background:

• Potassium silicate drilling fluids (PSDF) are industrial byproducts from oil and gas extraction.
• PSDF shows potential for land reclamation applications.
• Limited research exists on PSDF's impact on soil microbial communities.

Purpose of the Study:

• To investigate the effects of PSDF application on soil bacterial and fungal abundance and composition.
• To assess the influence of PSDF usage levels (unused, used once, used twice) on soil microbiota.
• To analyze these effects across different soil textures (clay loam, loam, sand) in Alberta, Canada.

Main Methods:

• Field study involving application of unused, used once, and used twice PSDF to three distinct soil types.
• Microbial analysis using dilution plate counts for total fungal and aerobic bacterial colony-forming units.
• Serial growth experiments to quantify anaerobic denitrifying bacteria.

Main Results:

• Application of used PSDF (≥40 m3/ha) significantly impacted soil microbial flora across all soil types.
• Used PSDF addition led to increased total fungal and aerobic bacterial counts.
• Significant increases in anaerobic denitrifying bacteria were observed with used PSDF application.
• The ratio of bacterial to fungal colony-forming units was altered by used PSDF.

Conclusions:

• Used PSDF demonstrably alters soil bacterial and fungal populations.
• The findings suggest PSDF can influence soil microbial ecology, relevant for land reclamation strategies.
• Further research is needed to fully understand the long-term implications of PSDF on soil health.