Algal treatment of wastewater generated during oil and gas production using hydraulic fracturing technology

Abstract

Hydraulic fracturing technology is widely used for recovering natural gas and oil from tight oil and gas reserves. Large volumes of wastewater, flowback water, are produced during the fracturing process. This study examines algal treatment of flowback water. Thirteen microalgae strains consisting of cyanobacteria and green algae were examined. Wastewater quality before and after algae treatment, as well as volatile matter, fixed carbon and ash contents of the biomass grown in flowback water were examined. The experimental results demonstrated that microalgae can grow in flowback water. The chemical composition of the algal biomass produced in flowback water was strain specific. Over 65% total dissolved solids, 100% nitrate and over 95% boron reduction in flowback water could be achieved. Hence, algal treatment of flowback water can significantly reduce the adverse environmental impact of hydraulic fracturing technology and produce biomass that can be converted to bioproducts.

Removal of total dissolved solids from wastewater using a revolving algal biofilm reactor

“…Renuka, Sood, Ratha, et al () found that an algae consortium reduced TDS by 28% (from 1,120 to 806 mg/L). More than 50% reduction of TDS from mixed industrial wastewaters was reported with the consortium of Chlorella and Phormidium after 20 days of incubation (Das, Ramaiah, Pereira, & Naseera, ), while even higher TDS removal efficiency (65%–80%) was reported in industrial wastewaters (Khan et al, ), oil and gas production wastewater (Lutzu & Dunford, ), and distiller wastewater (Krishnamoorthy et al, ). From a percentage perspective, the TDS removal efficiency reported in this work (TDS‐E [%], Table ), particularly for the BC reactor, was in the lower end compared to the date reported in previous research.…”

“…In this work, the BC and RAB reactors were based on the continuous culture resulting in a much higher volumetric removal rate (i.e., TDS‐R volume [mg/L‐day], Table ). For example, the BC reactor removed TDS at a rate of 21–121 mg/L‐day (Table ) and the RAB system removed at 101–2,783 mg/L‐day, while the TDS removal rates of the previous reports were calculated as 9 mg/L‐day (Maity et al, ), 25 mg/L‐day (El‐Bestawy, ), 45 mg/L‐day (Renuka, Sood, Ratha, et al, ), 130 mg/L‐day (Das et al, ), 349 mg/L‐day (Lutzu & Dunford, ), 9–30 mg/L‐day (Khan et al, ), and 4 mg/L‐day (Krishnamoorthy et al, ). With the further process optimization such as light intensity, TDS removal efficiency by the RAB and BC reactors can be further increased.…”

“…Compared to the existing methods, biological absorption by microalgae is a mild and environmental friendly method for TDS removal. Algal cells absorb TDS species as nutrients and minerals to support their physiology and metabolisms while reducing TDS in water (Cho, Luong, Lee, Oh, & Lee, ; Khan, Shamshad, Waqas, Nawab, & Ming, ; Krishnamoorthy, Manickam, & Muthukaruppan, ; Lutzu & Dunford, ; Renuka, Sood, Ratha, Prasanna, & Ahluwalia, ; Sydney et al, ; Zhou, Li, et al, ). A consortium of filamentous algae was reported to reduce TDS of sewage water from 1,120 to 806 mg/L over 6 days (Renuka, Sood, Ratha, Prasanna, & Ahluwalia, ).…”

“…Khan et al () reported 79% TDS removal from industrial wastewater within 12 days. In oil and gas production wastewater treatment, algae can remove up to 65% TDS over 30 days (Lutzu & Dunford, ). Krishnamoorthy et al () used blue‐green algae to treat distiller wastewater with 64%–80% TDS removal over 7 days.…”

Heterogeneous degradation of oil field additives by Cu(II) complex‐activated persulfate oxidation

“…Large amounts of wastewater are produced during fracturing process to extract oil from deep shale strata. [1][2][3] Consequently, polluted water will threaten the health and viability of all living organisms. 4 Guar gum is considered one of the main component of oilfield wastewater.…”