School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China E-mail:
Water Sci Technol. 2021 Mar;83(5):1230-1241. doi: 10.2166/wst.2021.053.
This work constructed a divided diaphragm seawater electrolysis system with two tandem packed towers for the synergistic removal of NO and SO. The first tower was mainly used to oxidize NO and SO by AC (active chlorine), and the second tower was used to further absorb NO. The factors affecting on NO removal, including ACC (active chlorine concentration), pH value, initial NO concentration and temperature in the oxidation tower were investigated. Moreover, the effect of different inlet gas concentrations and current values were explored. The results showed that with the increase of ACC, the NO and NO removal efficiency increased rapidly, but when the ACC was higher than 500 mg/L [Cl], the removal efficiency did not increase further in the oxidation tower. Low pH values in the oxidation tower were favorable for NO removal. NO removal efficiency reached a maximum at 40 °C. Higher NO and SO concentrations were favorable for NO removal. The decline of pH in the anode cell was not conducive to the storage of AC in the continuous electrolysis removal process. NO and SO were almost completely removed after being scrubbed in the oxidation and absorption towers. The relationship between current and removal efficiency of NO and SO in the oxidation tower was also analyzed. Finally, the removal mechanism and the application prospects were discussed.
本工作构建了一个具有两个串联填充塔的分隔壁式海水电解系统，用于协同去除 NO 和 SO。第一座塔主要用于通过 AC（活性氯）氧化 NO 和 SO，第二座塔用于进一步吸收 NO。考察了影响 NO 去除的因素，包括氧化塔中的 ACC（活性氯浓度）、pH 值、初始 NO 浓度和温度，此外还考察了不同入口气体浓度和电流值的影响。结果表明，随着 ACC 的增加，NO 和 NO 去除效率迅速提高，但当 ACC 高于 500mg/L [Cl] 时，氧化塔中的去除效率不再进一步提高。氧化塔中较低的 pH 值有利于 NO 的去除。NO 去除效率在 40°C 时达到最大值。较高的 NO 和 SO 浓度有利于 NO 的去除。阳极室中 pH 值的下降不利于 AC 在连续电解去除过程中的储存。NO 和 SO 在氧化和吸收塔中被洗涤后几乎被完全去除。还分析了氧化塔中电流与 NO 和 SO 去除效率之间的关系。最后，讨论了去除机制和应用前景。
