火化烟气臭氧-微生物耦合同时脱硫脱硝机制研究

Funeral cremation flue gas contains dioxin, sulfur dioxide (SO2), nitrogen oxides (NOx), heavy metals, flue dust and other pollutants. Compared to the industrial flue gas, cremation flue has the characteristics of smaller quantity, larger capacity fluctuations and lower concentration of sulfur and nitrogen oxides. The existing approaches, including limestone-gypsum wet flue gas desulfurization and selective catalytic reduction denitrification, cannot cost-effectively treat cremation flue gas, and it is impossible to be simultaneous desulfurization and denitrification (SDD). Due to the nitric monoxide (NO) is difficult to be absorbed and oxygen is not conducive to anaerobic biochemical reactions, researches on biological removal of SO2/NOx are preceding slowly. Therefore, a novel and effective gas-phase oxidation and biological integrated system is developed in the project for the simultaneous removal of SO2 and NOx from cremation flue gases. .The present work aimed at researching on the SDD mechanism from cremation flue gas in an integrated ozone-biological system. Firstly, the SDD mechanisms of ozone gas phase oxidation and liquid absorption will be proposed. Secondly, on the basis of isolated Citrobacter sp. strain HCSR and sulfur-oxidizing bacteria，an attempt will be made to screen effective mutant strains with mesophilic and alkalophilic properties. A study will be developed to optimize the sulfate (SOx2-), nitrate (NOx-) biological removal processes and microbial community structure. The bio-reduction mechanism and kinetic analysis shall be also investigated. Lastly, an integrated ozone-biological reactor system will be demonstrated. The performance of the system will be monitored under selected operating conditions. The elucidation of the SDD mechanism will contribute to the development of a new type of simultaneous removal and resource utilization technology from low-concentration flue gas pollutants.

殡葬火化排放烟气中含有二噁英、二氧化硫（SO2）、氮氧化物（NOx）、重金属和烟尘等多种污染物。火化烟气相比于工业燃煤烟气具有总量少、处理量波动大、硫氮氧化物浓度低等特点，现有脱硫脱硝技术处理火化烟气经济性较差，且很难同时脱硫脱硝。为解决微生物法烟气脱硫脱硝存在一氧化氮难以被吸收、氧气不利于生化反应等问题，本课题提出了符合火化烟气特点的"气相氧化-微生物耦合同时脱硫脱硝"的新思路。拟以烟气中的SO2 与NOx 为主要考察对象，研究臭氧气相氧化-液相吸收同时脱硫脱硝机制；利用已经分离得到的柠檬酸杆菌和硫氧化菌，筛选诱变获取高效嗜温嗜碱菌株，优化吸收液中硫酸盐（SOx2-）、硝酸盐（NOx-）生物脱除工艺及微生物种群结构，进行生物还原机理与动力学分析；设计新型臭氧-微生物耦合反应器小试系统。臭氧-微生物耦合同时脱硫脱硝机制的阐明，将有助于开发低浓度烟气污染物的新型同步去除、资源化利用技术。

遗体火化烟气中主要污染物的综合消减技术研究在我国具有重大社会价值和科学意义。针对火化烟气总量较少，处理量波动性大，SO2、NOx浓度较低，NOx/SOx比例较高等特点，本项目使用臭氧气相氧化-微生物耦合法同时脱除火化烟气中主要污染物NOx和SO2。本项目以模拟烟气中的SO2 与NO为主要考察对象，研究了臭氧气相氧化-液相吸收同时脱硫脱硝机制；从制药废水等污泥中驯化筛选到硫酸盐还原菌、反硝化菌和硫氧化菌，优化了培养条件；开展了生物脱硫脱氮、生物硫氧化实验室小试实验，优化硫酸盐（SOx2-）、硝酸盐（NOx-）生物脱除最佳工艺条件及关键限制因素；成功实现同步脱硫脱硝之后，运用变性梯度凝胶电泳对不同NO3-/SO42-条件下的菌群进行分析，结果显示：反硝化细菌和硫酸盐还原菌能够和谐共存，并在菌群中发现了6大类微生物；在嗜盐嗜碱硫酸盐还原反应器中，最佳的COD/SO42-为4.0，最佳的水力停留时间为18h，硫酸盐去除率可达97.8±1.11%，去除速率达6.26±0.0710 kg m-3 d-1；最后，项目组在山东省诸城市殡仪馆安装了一套“火化烟气臭氧-微生物耦合同时脱硫脱硝系统小试装置”。“气相氧化-微生物耦合同时脱硫脱硝”技术，解决了微生物法烟气脱硫脱硝存在一氧化氮难以被吸收、氧气不利于生化反应等问题，该机制的阐明，有助于开发低浓度烟气污染物的新型同步去除、资源化利用技术。