【作者】 卢永；

【导师】 张建法； 严莲荷；

【作者基本信息】 南京理工大学 ， 化学工程与技术， 2010， 博士

【摘要】 焦化废水COD高、毒性大、可生化性差,是一种成分极其复杂的难处理废水。目前,焦化废水处理工艺主要有A/O、A²/O、A²/O²、SBR、MBR等。但这些方法COD、氨氮处理效果不稳定,出水色度高,工艺复杂、成本高,不能满足处理与回用要求。课题研究了基于催化微电解、固定化活性污泥及固定化白腐菌技术的处理工艺,并进行了现场中试研究。根据焦化废水的特点,开发了HD TMAB改性沸石强化Fe-Cu催化微电解预处理方法,并确定了最佳工艺条件：Fe：Cu：沸石质量比为5：1.25：0.5,pH为4.0,HRT为45min,曝气量为15 L/（L废水min）（以下用L/（L min）表示）。该法氮杂环化合物去除率达68.5%,硫杂环化合物可被完全去除。预处理对后继生化处理具有很好的促进作用。有效解决了传统微电解法适用pH范围窄、易板结问题。为实现焦化废水同时脱氮除碳,分别在SBR和UASB反应器中选育了适应于焦化废水的高效好氧活性污泥和厌氧活性污泥。探索了基于PVA-SA包埋技术的好氧、厌氧活性污泥联合固定化体系：PVA 10%,SA2%,CaC03投加量0.5%,Si02投加量2%,活性炭投加量2%,污泥包埋量1：1（W/W）,饱和H3B03+2%CaCl2作为交联剂,交联时间4h,采用1 mol/L KH₂PO₄硬化1 h。固定化活性污泥处理焦化废水的最佳条件：适宜的pH为7.5～8.5,HRT为21～27 h,曝气量为7.5～10.0 L/（h L）,液固比为4：1～6：1。GC/MS分析表明,该法可将焦化废水中主要有机物均降解到未检出水平。固定化活性污泥为多孔结构,机械性能好,使用寿命长达2年以上。解决了焦化废水中氨氮、酚、硫氰酸盐、氰化物等有毒物质的抑制问题。固定化活性污泥对焦化废水中有机物降解动力学方程为S=（2426+32.30113t）/（1+0.61873t）,固定化活性污泥SND脱氮动力学方程为固定化白腐菌对焦化废水中难降解有机物具有独特的降解优势。以焦炭为填料,采用白腐菌BAF深度处理焦化废水,并确定了最佳工艺条件：pH为5.5～6.5,温度为30～40℃,HRT为24 h。该法COD去除率稳定在60～70%,酚的去除率稳定在95～98%,出水水质可稳定达到《污水综合排放标准》一级标准。采用PVA+SA谎酸铵+氯化钙法固定化白腐菌,生物量高,孔隙率高,传质效果好,性能稳定,易于活化。深度处理焦化废水适宜的pH为5.0～6.5,温度为30～40℃,HRT为18～24h。出水可达到《污水综合排放标准》一级标准。通过比较研究确定了焦化废水回用工艺。催化微电解-固定化活性污泥-固定白腐菌MBR-RO工艺出水COD和氨氮浓度分别为28 mg/L和0.12 mg/L,挥发酚已降至未检出水平（<0.002 mg/L）,可回用于循环冷却水、锅炉水、城市杂用水等。现场中试结果表明：催化微电解-固定化活性污泥工艺出水COD在100～150mg/L,酚＜0.5 mg/L,氨氮＜5 mg/L,分别达到了《污水综合排放标准》二级和一级标准。催化微电解-UASB-固定化活性污泥中试工艺出水达到《污水综合排放标准》一级标准。新开发的工艺耐硫化物、氨氮和酚冲击负荷,无需进行混合液回流、污泥回流,流程短,占地少,剩余污泥少,运行成本比现行A²/O工艺低。更多还原

【Abstract】 Coking wastewater is a typical refractory wastewater which composed of toxic, highly concentrated contaminants. To date, many processes have been applied to coking wastewater treatment, such as A/O, A²/O, A²/O², SBR and MBR. Due to the instable removal effect of COD, NH₄⁺-N and color, most of these expensive and complex processes could not meet the need of emission and recycle. The process based on catalytic micro-electrolysis, immobilized activated sludge and immobilized white rot fungus were studied for coking wastewater treatment in this study. The field pilot scale test was also conducted to investigate the treatment effect.Fe-Cu catalytic micro-electrolysis by HD TMAB modified zeolite strengthening was applied for coking wastewater pretreatment. The optimal pH, HRT, material ratio （W/W） and aeration rate for catalytic micro-electrolysis were 4.0,45 min, 5（Fe）:1.25（Cu）:0.5（zeolite） and 15 L/（L min）, respectively. The GC-MS analysis results indicated that,68.5 percent nitrogen-containing heterocyclic compounds were removed and sulfur-containing heterocyclic compounds were degraded completely. Fe-Cu catalytic micro-electrolysis had many advantages such as wider pH range in application, anti impulsion load, low running cost, not agglomerate and etc.The high efficient anaerobic activated sludge and aerobic activated sludge were selected and bred in SBR and UASB reactors, respectively. To prepare immobilized activated sludge, a method based on PVA-SA embedding technique was excogitated as follows:10% PVA （W/W）,2% SA,0.5% CaCO₃,2% SiO₂,2% powdered activated carbon （PAC） and 50% concentrated aerobic activated sludge were mixed together. The mixture was dropped into cross-linking agent, which composed of saturated boric acid and 2% CaCl₂（w/v） solution, and kept for 4 h to form spherical beads, then transferring to 1 mol/L KH₂PO₄ solution and immersing for 1 h. For biodegradation of coking wastewater by immobilized activated sludge, pH ranging from 7.5 to 8.5, HRT ranging from 21 h to 27 h, aeration rate ranging from 7.5 L/（h L） to 10.0 L/（h L） and liquid-solid ratio ranging from 4:1 to 6:1 created suitable conditions, respectively. The results of GC/MS analysis indicated that the main organic contaminants were entirely degraded. The immobilized activated sludge gels formed in porous structure had good mechanical properties, intensity, elasticity, aeration endurance and a service life more than 2 years. The inhibitory effects of toxic compounds such as phenols, ammonia, free cyanide and thiocyanate, on coking wastewater biodegradation were reduced significantly by immobilization technology. The kinetic equation for organic compounds in coking wastewater biodegradation by immobilized activated sludge could be expressed as S=（2426+32.30113t）/（1+0.61873t）. And the kinetic equation for SND could be expressed as [ln（S₀/S_e）]/S₀-S_e=0.12648·（t/S₀-S-e）+0.00192.The white rot fungus immobilized had a strong ability to degrade the refractory and toxic organic compounds in coking wastewater. The white rot fungus immobilized on coke was applied for coking wastewater advanced treatment in a BAF reactor. And pH ranging from 5.5 to 6.5, temperature ranging from 30℃to 40℃, and 24 h of HRT create suitable conditions, respectively. The removal rates of COD and phenol were about 70% and 98%, respectively. Parameters of the effluent could meet first class discharge standard of Integrated Wastewater Discharge Standard （GB8978-96）. The white rot fungus immobilized in PVA+SA-（NH₄）₂SO₄+CaCl₂ gels had many advantages such as porous structure, high porosity, good mechanical properties, high biomass and good mass-transfer performance and etc. The effluent of this process could meet first class discharge standard of Integrated Wastewater Discharge Standard under the suitable condition as follows:pH ranging from 5.0 to 6.5, temperature ranging from 30℃to 40℃, and HRT ranging from 18 h to 24 h.Process composed of catalytic micro-electrolysis, immobilized activated sludge, white rot fungus MBR and RO was ideal treatment schemes for coking wastewater recycle. COD, NH4⁺-N and phenol in final effluent were 28 mg/L,0.12 mg/L and not detected （below 0.002 mg/L）, respectively. The effluent could be recycled for industrial circulating cooling water, industrial boiler water and urban miscellaneous water.The field pilot scale test was conducted for coking wastewater treatment. The effluent of catalytic micro-electrolysis and immobilized activated sludge process could meet second class discharge standard of Integrated Wastewater Discharge Standard. And final concentrations in the effluent of 100～150 mg/L COD,< 5 mg/L NH₄⁺-N and <0.5 mg/L phenol were obtained.The effluent of catalytic micro-electrolysis, UASB and immobilized activated sludge process could meet first class discharge standard of Integrated Wastewater Discharge Standard. And final concentrations in the effluent of 80 mg/L COD,4 mg/L NH₄⁺-N and 0.2 mg/L phenol were obtained. These processes had many such as short flow, small floor area, easy operation, no sludge or wastewater return, impact load resistance, low construction and operating cost.更多还原