【作者】 常亚红；

【导师】 肖举强； 李杰；

【作者基本信息】 兰州交通大学 ， 市政工程， 2021， 硕士

【摘要】 苯胺是重要的化工原料,随着其用量的增加,排放到水环境中的苯胺也随之增加,危害生态环境和人体健康。作为新型生物膜反应器的一种,SBBR以其良好的脱氮效果、优越的沉降性能、较高的处理效率等特性得以应用广泛。载体的选择对SBBR处理效果有重要影响。基于普通PVA载体存在微生物密度低、生物相不丰富、微生物活性低、挂膜速度慢等缺陷,依次引入天然凹土改性普通PVA载体,阴离子表面活性剂十二烷基硫酸钠(SDS)修饰凹土改性PVA载体,阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)修饰凹土改性PVA,得到3种不同的复合型PVA载体,分别记为AT-PVA、SDS/AT-PVA、CTAB/AT-PVA。通过扫描电镜分析比较4种载体的微观形貌差异,发现改性后的PVA载体均具有更为粗糙的载体表面,孔结构更为丰富,比表面积更大;通过接触角测试表征了4种PVA载体的亲疏水性,表明改性后的PVA载体分为亲水性和疏水性两类;通过Zeta电位的测定发现:改性PVA载体可分为表面正电性和表面带负电性。CTAB/AT-PVA载体表面带正电荷,电荷量为8.3mv,其余PVA载体表面均带负电荷。相比于普通PVA以及AT-PVA,SDS/AT-PVA载体表面带有更多的负电荷;通过红外光谱分析,发现凹土改性的3种载体谱图均出现了凹土的特征峰,表明达到了改性效果。通过上述表征分析,推测CTAB/AT-PVA载体更有利于微生物附着,应用于苯胺废水的处理具有更好的效果。在SBBR反应器的运行中,投加不同改性PVA悬浮载体,控制进水水质及各组反应器的运行条件一致,期间进水苯胺浓度按梯度提高。通过挂膜、驯化及稳定运行三个阶段共98个周期,反应器运行共计49 d。对比各阶段的出水水质,结果表明:反应器启动的最初3 d,只有活性污泥未添加PVA载体的反应器启动速度更快,初期去除率更高。但随着实验继续运行,在驯化阶段及运行稳定阶段,投加PVA载体的反应器去除效果迅速好于活性污泥对照组反应器。对比投加PVA载体的4组SBBR反应器,出水效果:投加阳离子复合改性的CTAB/AT-PVA载体的反应器,对苯胺等污染物的降解效果最好,其COD、苯胺、氨氮的平均去除率依次为:93.4%、95.16%、88.40%。综合处理效果优劣排序是:CTAB/AT-PVA>AT-PVA>SDS/AT-PVA>普通PVA>未添加载体反应器。在平行对比选出效果最好的CTAB/AT-PVA载体后,进行单因素实验影响研究确定最佳工况。实验具体的影响因素包括:CTAB/AT-PVA载体最佳填充比、该SBBR系统的最佳pH以及最佳温度。实验维持进水苯胺浓度为250 mg/L不变,除要控制的单一变量以外,反应器运行参数与上一环节相同。通过苯胺、氨氮及TN的去除效果对比,得出以下结论:投加CTAB/AT-PVA载体的SBBR工艺处理一定浓度的苯胺废水时,最佳载体填充比为30%,最佳p H为8左右,最佳温度为26～30℃,此时该SBBR系统处理效果更好。更多还原

【Abstract】 Aniline is an important chemical raw material.As its dosage increases,the amount of aniline discharged into the water environment also increases,harming the ecological environment and human health.As a new type of biofilm reactor,SBBR is widely used due to its good denitrification effect,superior sedimentation performance,and high treatment efficiency.The choice of carrier has an important influence on the effect of SBBR treatment.Based on the defects of ordinary PVA carriers such as low microbial density,insufficient biological phase,low microbial activity,slow filming speed,etc.,natural attapulgite was successively introduced to modify ordinary PVA carriers,and sodium dodecyl sulfate(SDS)was used to modify the cavities.Soil modified PVA carrier,cationic surfactant cetyl trimethyl ammonium bromide(CTAB)modified attapulgite modified PVA,and 3 different composite PVA carriers were obtained,which were denoted as AT-PVA and SDS/AT-PVA,CTAB/AT-PVA.By scanning electron microscope analysis and comparing the microscopic morphology differences of the four types of carriers,it is found that the modified PVA carrier has a rougher carrier surface,richer pore structure and larger specific surface area;The contact angle test characterizes the hydrophilicity and hydrophobicity of the four PVA carriers,indicating that the modified PVA carriers are divided into two types:hydrophilic and hydrophobic;through the measurement of Zeta potential,it is found that the modified PVA carrier can be divided into surface positive And the surface is negatively charged: the surface of CTAB/AT-PVA carrier is positively charged,and the charge amount is 8.3 mv,and the surface of the other PVA carriers are negatively charged.Compared with ordinary PVA and AT-PVA,the surface of SDS/AT-PVA carrier has more negative charges;through infrared spectroscopy analysis,it is found that the three carrier spectra modified by attapulgite all have characteristic peaks of attapulgite,indicating The modification effect is achieved.Through the above characterization analysis,it is speculated that the CTAB/AT-PVA carrier is more conducive to the attachment of microorganisms,and it has a better effect when applied to the treatment of aniline wastewater.During the operation of the SBBR reactor,different modified PVA suspended carriers were added to control the influent water quality and the operating conditions of each group of reactors were consistent,during which the influent aniline concentration was increased according to a gradient.A total of 98 cycles were passed through the three stages of film coating,domestication and stable operation,and the reactor operated for a total of 49 days.Comparing the effluent quality of each stage,the results show that: in the first 3 days of reactor startup,only the activated sludge reactor without PVA carrier has a faster startup speed and a higher initial removal rate.However,as the experiment continued to run,during the domestication stage and the stable operation stage,the removal effect of the reactor with PVA carrier was faster than that of the activated sludge control reactor.Compared with 4groups of SBBR reactors with PVA carrier,the water output effect: the reactor with cationic composite modified CTAB/AT-PVA carrier has the best degradation effect on aniline and other pollutants.The average removal rate of COD,aniline,and ammonia nitrogen is 93.4%,95.16%,88.40%.The order of the comprehensive treatment effect is: CTAB/AT-PVA>AT-PVA> SDS/AT-PVA> ordinary PVA> reactor without carrier.After parallel comparison and selection of the CTAB/AT-PVA carrier with the best effect,single-factor experiments were conducted to determine the best working conditions.The specific influencing factors of the experiment include: the best filling ratio of CTAB/AT-PVA carrier,the best p H of the SBBR system and the best temperature.In the experiment,the influent aniline concentration was kept unchanged at 250mg/L.Except for the single variable to be controlled,the reactor operating parameters were the same as the previous link.Through the comparison of the removal effect of aniline,ammonia nitrogen and TN,the following conclusions are drawn: when the SBBR process with CTAB/AT-PVA carrier is used to treat a certain concentration of aniline wastewater,the best carrier filling ratio is 30%,and the best p H is about 8,The best temperature is 26～30℃,at this time the SBBR system has a better processing effect.更多还原