【作者】 洪思奇；

【导师】 冯传平；

【作者基本信息】 中国地质大学（北京） ， 环境科学与工程， 2014， 博士

【摘要】 石油开采过程中需要大量的压裂水，在压裂水使用过程中应避免BaSO4沉淀的产生。由于石油钻井经常与废弃的煤矿和酸矿废水排泄点在地理位置上重合，因此，美国宾州某能源公司开始寻找将酸性矿山废水（AMD）处理后替代市政用水的可行性方法。然而，AMD含有高浓度的金属离子和硫酸根离子（500-1000mg/L），在作为压裂水使用之前必须对其进行处理，但是目前的处理方法都存在很多弊端。虽然吸附方法对硫酸盐去除速度快，但目前的吸附剂都存在对硫酸盐吸附量有限的问题。本研究旨在开发一种新型的活性炭改性方法用以去除AMD中的硫酸盐。本研究应用聚吡咯改性活性炭，在活性炭负载聚吡咯之后，所含的氮携带一个正电荷，能够有效地吸附水中带负电的硫酸根离子。同时，聚吡咯具有氧化还原特性，通过对其还原可以使氮转为中性，使吸附的硫酸盐脱离下来而达到活性炭再生。本研究对煤质活性炭（UC1240）、硬木质活性炭（RGC40）和橡木质活性炭（GC）三种不同类型活性炭进行了改性；同时研究不同吡咯单体浓度、FeCl3浓度、合成温度和氧化方法等实验条件下改性的活性炭对硫酸盐去除效果的影响。实验结果表明，在25oC下，吡咯单体浓度为2mol/L、FeCl3浓度为2mol/L时，对硫酸盐的去除效果最好。在改进的吸附等温实验中，其对硫酸盐的吸附量为44.7mg/g。在处理AMD的小型快速柱实验（RSSCT）中穿透床体（BV）积达到36个。通过不同的表征手段，发现RGC在负载了聚吡咯之后表面带有0.8meq/g正电荷，改性后的RGC含有12.9%的氮。通过计算，其中9%的氮具有吸附硫酸盐的活性。与此同时，电化学还原方法可对使用过的活性炭再生。实验结果表明，在连续电化学再生装置中，-2V的电化学还原可以使95%的硫酸盐解析出来，同时+0.9V的电化学氧化可以使活性炭继续吸附硫酸盐，恢复到60%的吸附能力。综上所述，本研究中的改性活性炭能够有效去除AMD中的硫酸盐，同时可以电化学还原再生，是一种经济有效的AMD处理方法。本研究不仅为活性炭改性和再生提供了一条新途径，也为提高硫酸盐的去除效率提供了技术支撑和理论基础。更多还原

【Abstract】 Many companies use hydro fracture to release petroleum from the shale underground.The fracking water demand is large, and the precipitate should be prevented. An energycompaniy has sought acid mine drainage water as a viable alternative to municipally-developed water. The rationale for this is that the locations of fracking wells oftenoverlaps geographically with regions of abandoned coal mines and acid mine drainage.The traditional acid mine drainage contains500-1000mg/L sulfate. There are severallimits in current technology for sulfate removal. The adsorption method is rapid and easybut it has limited sorption capacity.A novel method of removing sulfate from acid mine drainage water was developed bydepositing polypyrrole into the pores of activated carbon via in situ chemical oxidationpolarization. This polypyrrole-tailored activated carbon hosted positively chargedpolypyrrole functionality that offered sorption capacity for sulfate. Next, after thissorption, the same polypyrrole-GAC was electrochemically reduced such that thenitrogen functionality became neutrally charged, and released the sorbed sulfate. Then,this same polypyrrole-GAC was electrochemically oxidized such that it regained apositive charge, and again sorbed sulfate.When polarizing polypyrrole on activated carbon, three different activated carbonswere selected, namely bituminous carbon (UC1240), hard-wood carbon (RGC40) andwood-based carbon (Gran C). Specifically, in batch tests, the polypyrrole-grafted RGCachieved a sulfate loading of44.7mg/g, which was8times higher than for pristine RGC.Rapid small scale column tests (RSSCTs) appraised the polypyrrole-tailored activatedcarbons for removing773mg/L sulfate from acid mine drainage water. The morefavorably tailored carbon removed sulfate to full-breakthrough at36bed volumes. Thiscompared to1.5bed volumes for pristine activated carbon. In this tailored carbon, thenitrogen content was12.9%, as characterized by X-ray photoelectron spectroscopy. Permass and charge balance,9%of the nitrogen in the polypyrrole functionality was activefor capturing sulfate. In this tailored carbon, the nitrogen.Subsequent to these RSSCTs, electrochemical reduction at-2.0volts released95%ofthis sorbed sulfate. Next, subsequent oxidation at+0.9volts yielded a media that hadrestored60%of its initial sulfate-sorption capacity. Overall, the tailored activated carbon by polypyrrole can remove sulfate from acidmine drainage water. The spent activated carbon can be regenerated by electrochemicalreduction. The study herein guided a new orientation for modification of activated carbonand regeneration and it provided a fundamental theory of sulfate removal as well.更多还原