CHEMICAL CO-PRECIPITATION PROCESS FOR RECOVERY OF FLOW-BACK WATER, PRODUCED WATER AND WASTEWATER OF SIMILAR CHARACTERISTICS

摘要

Methods and systems for treating contaminated flow-back water produced by hydraulic fracture are provided. The method involves precipitating metals from the flow-back water stream in a first reaction using at least one oxidizing agent, at least one pH adjusting agent, a source of sulfate and carbonate ions, and at least one co-precipitation agent. The precipitated metals may be dewatered using a first filter and may be used as an additive to drilling mud. The flow-back water may be further purified in a second reaction by addition of at least one pH adjusting agent and hydrated lime to precipitate salts. The precipitated salts may be dewatered using a second filter and may be used as an accelerating additive to concrete. The purified flow-back water may be stabilized by the addition of at least one pH adjusting agent to provide a water stream that may be reused in the hydraulic fracture drilling process.