摘要：

针对油井采出废水中硫化物去除难的问题，采用分段递进式除硫工艺对油井采出废水经过UASB生物反应池和仿生池进行分段递进式回流处理。实验结果表明，采用分段递进式除硫工艺，调节采出废水中S/N为5.2∶2，补充一定量的HCO₃ ^-，设置回流比为2.7∶1条件下，采出废水中的硫化物（S^2-）去除率为95.8%，最大容积载荷6.46 kg/（m³·d）；硝酸盐（NO₃ ^--N）去除率达99.6%，最大容积载荷1.13 kg/（m³·d）。经SEM和XRD验证，硫代谢产物以单质硫（S⁰）为主，回收率83.8%，其次为SO₄ ^2-和S₂O₃ ^2-；硝酸盐代谢产物以N₂为主，产率72.4%，其次为NO₂ ^-。分段递进式除硫工艺不仅解决了采出废水中的硫化物去除难题，同时实现了资源回收（S⁰）和主要代谢终产物（如N₂）的无污染排放。

关键词: 油井采出废水, 硫化物, 分段递进式除硫工艺, 容积载荷, 单质硫回收

Abstract:

In response to the challenge of sulfide removal from oilwell produced wastewater, a segmented progressive sulfide removal process was adopted to treat the oilwell produced wastewater through UASB bioreactor and biomimetic reactor for segmented progressive reflux treatment. The experimental results showed that under the conditions of adopting the segmented progressive sulfide removal process, adjusting the S/N ratio of 5.2∶2 in the produced wastewater,supplementing a certain amount of HCO₃ ^-, and setting the reflux ratio of 2.7∶1, the removal efficiency of sulfide (S^2-) in the produced wastewater arrived to 95.8%, and the maximum sulfide volumetric load was 6.46 kg/(m³·d). The removal efficiency of nitrate (NO₃ ^--N) reached 99.6%, with the maximum nitrate volumetric load of 1.13 kg/(m³·d). The key metabolite of sulfide metabolism was elemental sulfur, with a recovery rate of 83.8%, which was verified by SEM and XRD simultaneously, and followed by SO₄ ^2- and S₂O₃ ^2-. While the key metabolite of nitrate metabolism was N₂, with a yield of 72.4%, and followed by NO₂ ^-. The new process not only solved the problem of efficient removal of sulfide and nitrate from the produced wastewater, but also realized resource recovery(S⁰) and non-pollution emission of metabolic end products(such as N₂).

Key words: oilwell produced wastewater, sulfide, segmented progressive sulfide removal process, volumetric load, recovery of elemental sulfur

中图分类号: 

• X703