Nutrient Enrichment of Wastewater Generated During Hydraulic Fracturing with Animal Wastewater to Enhance Microalgae Growth

Abstract

Hydraulic fracturing technology widely used for recovery of oil and gas from tight shale formations generate millions of gallons of wastewater. This study examined viability of algal remediation of the hydraulic fracturing wastewater (HFWW). Our previous studies have shown that although Oklahoma native algae strains can grow in HFWW, cell growth was constrained by the low nutrient concentrations in HFWW. Hence, the goal of this study was to examine the effect of nutrient supplementation of HFWW with another nutrient rich wastewater on microalgae growth. An Oklahoma, USA, native algae strain, Picochlorum oklahomensis, was selected for the study because of its high biomass productivity in wastewater. This study demonstrated that P. oklahomensis can grow in HFWW. Supplementation of the HFWW with animal wastewater enhanced biomass productivity and lipid content of the biomass. Chemical compositions of the wastewater before and after algae growth were significantly different indicating substantial amount of contaminant removal.