Wastewater treatment system and gas liquid partition valve

A wastewater treatment system comprising:

• an acid fermentation tank configured to produce acid fermentation-treated water by treating raw wastewater with acidogenic bacteria;
• a first flow path connected to the acid fermentation tank and configured to transmit the acid fermentation-treated water;
• a methane fermentation tank positioned under the acid fermentation tank, connected to the first flow path, and configured to produce biogas and methane fermentation-treated water by treating the acid fermentation-treated water transmitted by the first flow path with methanogenic bacteria, and an upper portion of the methane fermentation tank including an opening that communicates with the acid fermentation tank;
• a second flow path connected to the methane fermentation tank and configured to transmit the methane fermentation-treated water;
• and
• a gas type liquid partition valve provided at the opening, including a gas storage portion configured to store a predetermined amount of the biogas and discharge the biogas exceeding the predetermined amount to the acid fermentation tank, and configured to block the opening with the biogas stored in the gas storage portion.