文一污水站减少污泥产生量的污水处理技术

Oilfield Produced Water Treatment at Water-Treating Plant W-1 to Reduce Sludge Creation

为了减少文一污水站按现行工艺在高 pH(8.0～ 8.5 )下处理油田污水过程中产生的污泥量 ,开发了一种新的污水处理工艺。在室内实验条件下 ,用一种 pH调节剂将污水pH控制在 7.0～ 7.5 ,加入除铁剂、除铁增效剂各 10 0mg/L ,得到了最好的净水效果 (滤膜系数MF >30 ) ;与原污水相比 ,净化水污泥产生量由 10 .8g/L降至～ 1g/L ;5 0℃、15d静态腐蚀速率为 0 .0 0 89～ 0 .0 110mm/a ,平均 0 .0 0 97mm/a ;SRB菌数为 0 ,TGB菌数 0～ 10 1个 /mL ,与地层水完全配伍 ;矿化度和主要成垢离子浓度有所降低。在文一污进行了为期 47d的现场试验 ,结果表明 :①在pH 6 .8～ 7.2 ,除铁剂和增效剂加量分别为 15 0 ,130mg/L时 ,净水效果最好 ,外输水MF >2 8,SS 5mg/L ,含油 2mg/L ;②pH增大时污泥产生量增大 ,处理后水水质变差 ;③pH 6 .8～ 7.2 ,除铁剂 130mg/L ,增效剂 10 0mg/L为最佳净水条件 ,外输水MF >2 0 ;④净化水腐蚀性符合水质指标 ,主要腐蚀因素是二次沉降罐曝氧 ,加入Na2 SO3 可降低溶解氧含量 ,但引起水质下降 ;⑤试验期间污泥量减少 1/ 2～ 1/ 3。

To reduce sludge creation at water-treating plant W-1 in treating oilfield produced water according to the present high pH (8.0～8.5) technology, a new treating process is developed. Under laboratory experimental conditions the best water quality (filtralion factor MF>30) is obtained with pH value adjusted to within 7.0～7.5 by using a chemical and with Fe remover (FeR) of 100 mg/L and Fe removal enhancer (FeRE) of 100 mg/L introduced: the purified water produces ～1 mg sludge per liter instead of 10.8 mg/L for original produced water; the static corrosion rate in the purified water at 50℃ in 15 days accounts 0.008 9～ 0.011 0 mm/a, 0.009 7 mm/a in average; population of bacteria SRB is of zero and of TGB - 0 - 10 1 cell/mL; the TSD and main scaling ions are slightly reduced; the purified water is highly compatible with the reservoir formation water. In the field trial of the new technology performed at wastewater treating plant W-1 in 47 days following results are obtained: ① the best water quality is observed at pH value range 6.8～7.2 with FeR of 150 and FeRE of 130 mg/L added and in this case MF>28, SS=5 mg/L, and oil content 2 mg/L for the output water; ② at higher pH values the sludge creation is increased and the purified water quality - deteriorated; ③ at optimal pH value (6.8～7.2) and use levels of FeR (130 mg/L) and FeRE (100 mg/L) the MF value is of >20 for output injection water; ④ the corrosivity of the purified water is well below the specified limit (0.076 mm/a), the main factor in corrosion is exposure to air of the water in 2nd precipitation tank, Na 2SO 3 can be used to eliminate dissolved O 2 but causes deterioration of water quality; ⑤ the sludge creation is decreased by 50-66% during the trial; ⑥ the fluctuation in purified water quality is caused by the change in input water volume.