絮凝沉降-Fenton氧化-吸附法处理采油污水实验研究

Treatment of produced wastewater by flocculation settlement-Fenton oxidation-adsorption method

我国油田的采油污水绝大部分经处理后用于油田注水 ,但由于种种原因 ,还有一部分采油污水不能回注 .这部分水外排至环境中 ,对环境产生一定的影响 .本文以甘谷驿油矿采油污水为研究对象 ,采用絮凝沉降 -Fenton氧化 -吸附法对该采油污水进行外排处理实验研究 .考察了 pH值、H2 O2 投加量、Fe2 +投加量、氧化时间、吸附时间、活性炭加量对COD去除率的影响 .实验结果表明 ,最佳处理条件为絮凝剂选用聚合硫酸铁 ,沉降 30min ;pH为 3.0～ 4 .0 ,30 %双氧水加量为 8mL/L ,m (Fe2 +)∶m (H2 O)为 4 % ,氧化时间 12 0min ;活性炭加量 4 .0～ 5 .0 g/L ,吸附时间 12 0min .在这种处理条件下 ,可使污水含油量从 93.1mg/L降至 5mg/L以下 ,悬浮物含量从 172mg/L降至 10mg/L以下 ,CODCr值从 2 6 34mg/L降至 10 0mg/L以下 。

Most produced wastewater in the oilfields in our country is used for waterflooding, but a part of produced water is drained into the environment and produces a bad influence on the environment. The produced wastewater of Ganguyi Oilfield being taken as a research target, the result of the wastewater treatment method of flocculation settlement-Fenton oxidation-adsorption is studied in laboratory. The effects of pH value, the dose of H_2O_2, the dose of Fe^(2+), oxidation time, adsorption time, and the dose of active carbon on the removal efficiency of COD are investigated. The experimental results show that, the optimal treatment conditions are polyferric sulfate as flocculant, settlement time of 30 min; pH value of 3.0～4.0, 30%H_2O_2 of 8 mL/L, Fe^(3+) to H_2O mass ratio of 4%, oxidation time of 120 min; active carbon dose of 4.0～5.0 g/L, adsorption time of 120 min. Under these treatment conditions, the oil content in the wastewater can be reduced to 5 mg/L from 93.1 mg/L, the suspended substance can be reduced to 10 mg/L from 172 mg/L, and the COD_(Cr) value can be reduced to 100 mg/L from 2 634 mg/L. The treated produced wastewater reaches to the national primary standard.