Reuse of shale gas flowback and produced water: Effects of coagulation and adsorption on ultrafiltration, reverse osmosis combined process

Wei Shang; Alberto Tiraferri; Qiping He; Naiwen Li; Haiqing Chang; Chao Liu; Baicang Liu

doi:10.1016/j.scitotenv.2019.06.365

Reuse of shale gas flowback and produced water: Effects of coagulation and adsorption on ultrafiltration, reverse osmosis combined process

Sci Total Environ. 2019 Nov 1:689:47-56. doi: 10.1016/j.scitotenv.2019.06.365. Epub 2019 Jun 24.

Authors

Wei Shang¹, Alberto Tiraferri², Qiping He³, Naiwen Li⁴, Haiqing Chang¹, Chao Liu⁴, Baicang Liu⁵

Affiliations

¹ College of Architecture and Environment, Institute of New Energy and Low-Carbon Technology, Institute for Disaster Management and Reconstruction, Sichuan University, Chengdu, Sichuan 610207, PR China.
² Department of Environment, Land and Infrastructure Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy.
³ Chuanqing Drilling Engineering Company Limited, Chinese National Petroleum Corporation, Chengdu 610081, PR China.
⁴ College of Water Resource & Hydropower, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, PR China.
⁵ College of Architecture and Environment, Institute of New Energy and Low-Carbon Technology, Institute for Disaster Management and Reconstruction, Sichuan University, Chengdu, Sichuan 610207, PR China. Electronic address: bcliu@scu.edu.cn.

PMID: 31260898
DOI: 10.1016/j.scitotenv.2019.06.365

Abstract

The shale gas flowback and produced water (FPW) from hydraulic fracturing in the Sichuan province of China has relatively low to moderate levels of total dissolved solids (<20 g/L) and organics (<50 mg/L of dissolved organic carbon). As such, a combined ultrafiltration (UF), reverse osmosis (RO) system can be successfully applied to desalinate this feed water with the goal of reuse. However, the concentration of influent organic matter and particulates in the UF and RO stage is high, and the overall ionic and organics composition is highly complex, so that the membrane processes do not perform well, also due to fouling. To ensure the long-term and efficient operation of the UF-RO stages, a combined pretreatment of the FPW with coagulation and adsorption was investigated. The effect of different parameters on the performance on the system was studied in detail. Overall, the coagulation-adsorption pre-treatment greatly reduced fouling of the membrane processes, thanks to the high removal rate of turbidity (98.8%) and dissolved organic carbon (86.3%). The adsorption of organic matter by powdered activated carbon was best described by the Freundlich equilibrium model, with a pseudo second-order model representing the adsorption kinetics. Also, the various ions had competitive removal rates during the adsorption step, a phenomenon reported for the first time for FPW treatment. Also, an optimal dose of activated carbon existed to maximize fouling reduction and effluent quality. The overall treatment system produced a high-quality water streams, suitable for reuse.

Keywords: Adsorption; Coagulation; Flowback and produced water; Reverse osmosis; Ultrafiltration; Water quality.