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1. Corrosion of equipment, etc. Oilfield production and water injection tanks and pipelines, as well as the sewage tanks, vessels, and pipelines in the wastewater treatment plants of refineries, are all severely corroded by sulfur-containing wastewater. Since the wastewater contains large amounts of H2S, NH3, and CO2, as well as harmful ions such as Cl- and SO42-, along with a high number of bacteria, and the temperature is as high as 70–80°C, some of it also contains phenolic corrosive substances, failure to implement effective anti-corrosion measures can lead to severe corrosion of these equipment. This can result in thinning of the carbon steel surface, local perforations, bubbling, cracking, and stress corrosion cracking in the welds. 2. Analysis of corrosion causes: Different crude oils and production processes result in varying corrosive agents in the wastewater; as a result, the causes and mechanisms of corrosion differ to some extent. Generally speaking, however, the following points apply: 1. Corrosive agents such as H2S and NH3 present in sulfur-containing wastewater cause corrosion due to electrochemical reactions that generate H2S ； 2. Hydrogen embrittlement corrosion caused by hydrogen atom penetration ； 3. The wastewater contains large amounts of NH3, CN-, and Cl-. The substances formed as a result of their reaction with H2S, namely NH4HS and (NH4)2S, are highly corrosive ； 4. Phenolic corrosion agents can damage the coating, exacerbating corrosion. 3. Corrosion-resistant coating design: Conventional coatings (such as ordinary epoxy paint, epoxy coal tar pitch paint, epoxy phenolic paint, polyurethane paint, chlorosulfonated paint, etc.) cannot meet the required performance standards, whereas epoxy glass flake paint, epoxy furan paint, epoxy fiberglass, and epoxy polysulfide rubber paint have shown excellent results in practical applications by various organizations. Regardless of the anti-corrosion coating used, it is first necessary to understand the operating conditions of the equipment. Then, select an appropriate supporting solution based on the corrosion environment.