【作者】 王玉峰；

【导师】 陈克复；

【作者基本信息】 华南理工大学 ， 制浆造纸工程， 2014， 博士

【摘要】 非均相Fenton氧化技术具有H2O2利用率高、pH值适用范围广和催化剂可再生等优势，已成为Fenton技术改进和发展的重要方向，同时该技术也为造纸废水的深度处理提供了一条新的有效途径。本文以活化海泡石为载体，制备了Fe/Mn/海泡石非均相催化剂。采用UV/H2O2/催化剂组成的非均相Fenton体系对制浆废水进行了深度处理。将非均相Fenton技术与混凝和好氧处理工艺进行有机耦合，对造纸法烟草薄片废水进行了处理。海泡石的活化研究表明，酸活化和热活化是有效的活化方法，硝酸是优良的活化剂，海泡石通过硝酸活化，显著增加了比表面积，改善了内部孔道的结构和分布，增强了吸附能力。研究发现，在海泡石酸活化过程中，脱镁率与比表面积具有很强的关联性，可以作为衡量酸活化效果的一个重要依据。当脱镁率为59%左右时，海泡石的比表面积达到最大，吸附能力最强。酸活化海泡石再进行热活化可以显著改善海泡石的性能。实验得出优化的海泡石活化条件是：硝酸浓度2.0mol/L，酸活化温度40℃，酸活化时间120min，固液比1:20，焙烧温度300℃，焙烧时间3h。活化后海泡石的比表面积为活化前的3.4倍，吸附能力为活化前的2.66倍。以活化海泡石为载体，采用共沉淀法制备了Fe/Mn/海泡石非均相催化剂，采用XRD、SEM、XRF、BET等手段对催化剂进行了分析表征，结果表明，负载后，海泡石中铁和锰的含量大幅增加，海泡石的结晶度有所下降，铁和锰以单分散形式均匀存在于海泡石的表面和孔道内，负载后的海泡石仍然具有较大的比表面积和孔容积，这一性质保证了催化剂可以提供给更多的活性点，使其具有较高的催化活性。以对氯苯酚为模型污染物，对Fe/Mn/海泡石催化剂的催化性能进行了研究，结果表明，催化剂在pH3.0~9.0的范围内都具有较高的催化活性。催化剂连续重复使用5次，催化活性没有明显变化，并且铁的溶出量低于0.4mg/L，锰的溶出量低于0.2mg/L，具有良好的稳定性和重复使用性。非均相Fenton反应的机理研究表明，反应是在紫外光的作用下，催化剂中的Fe(Ⅲ)转变为Fe(Ⅱ)，并形成了二者之间的循环，同时产生了羟基自由基，是真正的非均相反应。采用非均相Fenton氧化技术对生化处理后的制浆废水进行深度处理，结果表明该技术对制浆废水具有很好的处理效果。当初始pH为3.0、过氧化氢用量为2.5mL/L、催化剂用量为1500mg/L、反应温度为30℃、反应时间为150min时，废水COD从380mg/L被降解至65mg/L左右。当初始pH为5.0、反应时间为180min，其他条件不变时，废水的COD可以降解至70mg/L以下，甚至当pH为7时，非均相Fenton体系依然具有较高的催化活性。催化剂连续使用4次，催化活性没有明显变化，金属离子的溶出量较低。为消除H2O2对废水COD测定结果的影响，建立了一种双波长光谱法快速测定COD的方法，得到了吸光度与COD之间的相关性方程：C OD173.57(A272A546)8.5577。通过与标准测试方法的比较，表明双波长光谱法具有较高的测量精密度和准确性，可以用于废水COD的快速测定。不但避免了H2O2对测量结果的干扰，而且缩短了测量时间，提高了工作效率。采用混凝+好氧处理+非均相Fenton技术的流程处理造纸法烟草薄片废水，通过响应面法对混凝和非均相Fenton工艺条件进行了优化，减少了化学品的消耗，降低了处理成本，处理后废水的COD约为63.5mg/L，色度为无色。该处理工艺为造纸法烟草薄片废水的达标排放提供了有效的途径。制浆废水和造纸法烟草薄片废水的GC-MS分析表明，经非均相Fenton氧化技术处理后，废水中的有机物种类大大减少，芳香族化合物、有机卤化物等高毒性物质被完全去除，大部分有机物被完全矿化或者被降解为低分子量的有机酸。更多还原

【Abstract】 Heterogeneous Fenton oxidation process with high utilization of H2O2, a wide range ofpH and catalysts reuse, has become an important improvement and development direction ofFenton technical, and provides an effective way for papermaking wastewater treatment. Inthis paper, Fe/Mn/sepiolite heterogeneous catalyst was prepared based on activated sepioliteas the carrier. Heterogeneous photo-Fenton process using Fe/Mn/sepiolite as catalyst wasstudied to degrade pulping wastewater, and a coupled coagulation-heterogeneous Fenton pro-cess was applied for the treatment of papermaking-reconstituted tobacco slice wastewater.Natural sepiolite was activated by acid and thermal pre-treatment to improve its perfor-mance. The results indicated that specific surface area of sepiolite was markedly increased,the structure and distribution of pores were improved, and the adsorption capacity was en-hanced by nitric acid activation. It was found that during the acid treatment there was a strongcorrelation between magnesium removal and specific surface area of sepiolite, and magnesi-um removal could be as the basis to evaluate the effect of acid activation. When magnesiumremoval was about59%, the maximum of specific surface area and the maximum of adsorp-tion capacity were obtained. The performance of sepiolite was further improved by ther-mal activation after acid activation. The optimized conditions of sepiolite activation were ni-tric acid concentration2.0mol/L, acid activation temperature40℃, acid activation time120min, solid-liquid ratio of1:20, calcination temperature300℃, and calcination time3h. Thespecific surface area of activated sepiolite was3.4times of natural sepiolite, the adsorptioncapacity of activated sepiolite was2.66times of natural sepiolite.Fe/Mn/sepiolite heterogeneous catalyst was prepared by coprecipitation method. Severalmethods such as XRD, SEM, XRF and BET were applied to investigate the characteristics ofsepiolite. It was also observed that the contents of iron and manganese increased significantly,the crystallinity of sepiolite degree decreased, iron and manganese present in the surface andpore of sepiolite in the form of monodisperse, specific surface area and pore volume were stilllarge.The catalytic performances Fe/Mn/sepiolite catalyst were studied by p-chlorophenoldegration. The results showed that the catalytic activity of catalyst was very high in the pHrange of3.0-9.0, the catalytic activity did not change obviously when catalyst was reusedcontinuously5times, and the elution amount of Fe was below0.4mg/L, the elution amountof Mn was below0.2mg/L. Mechanism studies of heterogeneous Fenton reaction showed thathydroxyl free radicals were generated during the circulation was formed between Fe(III) and Fe(II) under the action of UV, so it was is a real heterogeneous reaction.Heterogeneous photo-Fenton process was applied to treat pulping wastewater after aero-bic treatment. The results showed that heterogeneous Fenton process was a effective way foradvanced treatment of pulping wastewater. Under experimental conditions of initial pH3.0,H2O2dosage2.5mL/L, catalyst dosage1500mg/L, temperature30℃, and reaction time150min, COD was degraded from about380mg/L to about65mg/L. When initial pH was5.0,reaction time wad180min, other things were equal, COD was degraded to below70mg/L,even when the pH was7.0, the catalytic activity was still high. The catalytic activity did notchange obviously when catalyst was reused continuously4times, and the elution amounts ofFe and Mn were very low.A method for COD rapid determination by the dual-wavelength spectroscopic methodwas established to eliminate the influence of H2O2for COD determination. The correlationequation between the absorbance and COD was COD173.57(A272A546)8.5577.Compared with the standard testing method, the precision and accuracy of the equation wasreliable. The method can be used for the rapid determination of COD in wastewater.A coupled coagulation-heterogeneous Fenton process was applied for the treatment ofpapermaking-reconstituted tobacco slice wastewater. The process conditions were optimizedby response surface method. Under the optimized conditions, COD was degraded to about63.5mg/L, decoloration was nearly100%. It could be concluded that this technology wassuccessful for the treatment of papermaking-reconstituted tobacco slice wastewater.GC-MS analysises of pulping wastewater and papermaking-reconstituted tobacco slicewastewater showed that organic compounds was greatly reduced, aromatics and organic chlo-ride were completely removed, most organic compounds were completely mineralized or de-graded into small molecular organic acids.更多还原