碱式氧化调理-E+/ 微纳气泡臭氧两段耦合含油污泥减量化过程研究

Oil sludge, characterized as high generation rate, viscosity, emulsion, complex components, is one of the main pollutants from refining & chemical industry, and also belongs to hazardous waste according to the national hazardous waste listings. The disposal of oil sludge is a headache problem for managers due to the limitation of the hazardous waste treatment facilities up to now, and source reduction could be one of the options. To reduce oil content in the oil sludge, alkali oxidation process will be applied to condition the sludge, and oil could be floated and removed with the aid of the excess of air during the O3 generation. Ozonation has also been proved to be a promising way for the reduction of sewage sludge, while the utilization efficiency of traditional ozone in sludge system was low due to the slightly soluble in water and excess O3 emission from the reactor system. To improve the utilization efficiency of ozone, a novel ozonation process, combing the micro/nano ozone bubbles and the electro+, is proposed and designed, and the effect of the substances, e.g. ozone concentration, O3 dosage, sludge concentration and the operation conditions of pH and T, are to be optimized through the bench scale experiments. The mass transfer of O3 and excess O2 on the solid-liquid-steam micro-interface will be analyzed, and the synergistic effects of electro- micro/nano bubbles ozonation are to be assessed. The dewatering process of oil sludge is to be compared using the CST instrument. The disintegrate process of sludge are to be identified in terms of oil content, SCOD, TOC, TN and TP, and the reduction efficiency will be assessed by comparing the MLVSS/MLSS ratio before and after O3 aeration. The interaction process could provide a cost-efficient method for oil sludge reduction, which will be benefit for the decrease of hazardous waste generation rate, and reduce the treatment fee. The combining of the alkali oxidation condiitioning with O3 and Electro-mico/nano bubble ozonnation could contribute to the reduce of the oil sludge in the refining & chemical industry.

含油污泥来源复杂、黏度大、乳化充分，而处理困难，被归列入《国家危险废物名录(2016版)》。据此，提出基于碱式氧化调理-E+/微纳气泡臭氧协同作用的源头减量技术，通过降毒减容减少含油污泥末端处理成本。利用分步单元操作和逐步放大模拟相结合方式，考察pH值、臭氧浓度、气泡尺寸、投加量等对污泥改性调理脱油的作用和机理；分析E+-微纳气泡协同作用下，电流强度、极板类型等强化臭氧利用效率；比较单段式和二段式系统微纳臭氧分点精准投加方式，优化各工况条件参数范围，建立污泥调理、脱油、污泥破壁和有机物矿化的平衡关系，拓宽降毒后含油污泥的出路；研究微纳臭氧气泡微界面过程特征和行为规律，揭示“固-液-气”三相体系内污油与固体颗粒界面关系、微纳气泡受力性能和迁移转化规律，阐明碱式氧化调理-E+/臭氧氧化对含油污泥减量协同增效机制，评价系统内臭氧利用效率。从而为炼化行业中含油污泥类危险废物源头减量提供新思路。

含油污泥是炼厂及相关石化企业重要的危险废物，来源复杂、黏度大、乳化充分，处理困难。本课题开发了基于碱式氧化调理-E+/微纳气泡臭氧协同作用的含油污泥源头减量技术，获得以下主要结论：（1）当pH为13（NaOH调节），温度80℃，处理时间6 h时，油泥溶胞率达46.6%。过氧化钙可替代氢氧化钠进行氧化调理，当CaO2加量为40 mg/gTS时，油泥溶胞率达34.1%。（2）在pH为3，臭氧剂量为0.27 gO3/gTS，TS为2%时，微纳气泡中SCOD增加了390%，污泥最大TS去除率为41.9%。其中，乙酸为主要成分，其产量为590±7.1 mg/L。（3）微纳气泡中溶解臭氧平衡浓度为34.1 mg/L，而常规气泡仅为24.2 mg/L。微纳气泡的kLa和•OH浓度为0.2293 min−1和1.29 μg/L，是常规臭氧化的2倍。（4）微气泡臭氧对不同烃类组分 （nC7-C10、nC11-C20、nC21-C30和nC31-C40）的TPH具有广谱去除率，平均去除率为71.7-79.5%。其中主要中间产物包括42.6%羧酸、18.8%酚类和13.9%醇类和CO2等。（5）在pH=9，电流密度为30 mA/cm2，极板间距为3 cm，单段式E+-微纳气泡臭氧处理效果优于两段式和单独电解，SCOD增至6272 mg/L，TPH去除率增至87%。（6）E+-微纳气泡臭氧处理含油污泥过程中，原位生成的H2O2浓度最高为6.2 mg/L，•OH最高为5.5×10-4 mg/L。（7）在O3/g-C3N4/Fe2O3/Pr6O11中，60分钟内去除了约76.9％TPH，38.8%TPH被矿化，而单独O3仅去除了约47.3％TPH。（8）开发的Sb-g-C3N4催化剂可有效催化臭氧氧化含油污水中萘，在较高负载量（9 mM）下能够在5分钟内完全降解萘，65.6%萘被矿化。