安全、健康和环境

达尔其油田产出污水存在离子成分复杂(高矿化度、低Ca²⁺/Mg²⁺)、高悬浮物、高含油的问题，针对原有水处理工艺难以使出水水质达到回注标准的难题，构建了“预氧化-硬度调节-PAFS絮凝”协同处理体系。通过系统考察预氧化剂(NaClO)、硬度调节剂(Ca(OH)₂)、絮凝剂(PAFS)的添加浓度及反应时间等关键参数对污水处理效能的影响，确定最优工艺条件。实验结果表明，依次加入30 mg/L NaClO、80 mg/L Ca(OH)₂、150 mg/L PAFS,且絮凝反应60 min时，污水中悬浮物浓度由初始的273 mg/L降至9.5 mg/L(去除率96.5%),含油量由89 mg/L降至8.4 mg/L(去除率90.6%),实现了低药剂浓度下污染物的高效去除。处理后的水质完全满足SY/T 5329—2022Ⅱ级回注要求，该技术在保障水质达标的同时有效控制了处理成本，为低Ca²⁺/Mg²⁺、高悬浮物、高含油采出污水的处理提供了经济可行的解决方案。

The produced wastewater from the Da′erqi Oilfield exhibits complex ionic composition(high mineralization, low Ca²⁺/Mg²⁺), high suspended solids, and high oil content. To address the challenge that the original water treatment process is hard to make the effluent quality meet the reinjection standards, this study established the “pre-oxidation-hardness adjustment-PAFS flocculation” synergistic treatment system. By systematically investigating the effects of key parameters, which include the addition concentrations of pre-oxidant(NaClO), hardness regulator(Ca(OH)₂), and flocculant(PAFS), as well as reaction time on wastewater treatment efficiency, the optimal process conditions were determined. The experimental results showed that when 30 mg/L NaClO, 80 mg/L Ca(OH)₂, and 150 mg/L PAFS were added sequentially, and the flocculation reaction lasted for 60 minutes, the suspended solid concentration in the wastewater decreased from the initial 273 mg/L to 9.5 mg/L(removal rate of 96.5%). The oil content decreased from 89 mg/L to 8.4 mg/L(with a removal rate of 90.6%), achieving efficient removal of pollutants at low reagent concentrations. The treated water fully complies with SY/T 5329—2022 Grade Ⅱ reinjection requirements.. While ensuring that the water quality meets the standard, this technology effectively controls the treatment cost, providing an economically feasible solution for the treatment of produced wastewater with low Ca²⁺/Mg²⁺, high suspended solids, and high oil content.