Gas field oil-containing alcohol-containing sewage pretreatment system and method

The invention belongs to the technical field of gas filed exploitation sewage treatment and particularly relates to a gas field oil-containing alcohol-containing sewage pretreatment system and method. After being subjected to processes of removing oil, homogenizing, regulating a pH value, oxidizing to remove iron, flocculating, settling through an inclined plate, gathering and separating, roughly filtering and finely filtering, the gas field oil-containing alcohol-containing sewage enters a raw material water tank. The sewage pretreatment system and method disclosed by the invention can be adaptive to water quality fluctuation of the oil-containing alcohol-containing sewage; through the pretreatment, the mechanical impurities, the oil components and the iron ions in the sewage are almost completely removed, so that a methanol recycling device is guaranteed to be stably operate; the treatment method has the advantages of being simple, convenient to operate, low in treatment cost and high in treatment efficiency.