Abstract:

An experiment of antibiotic residue co-processing was carried on a 300MW pulverized coal fired boiler. The migration characteristics of chromium and arsenic were traced, and the environmental impact during the co-combustion was studied. The samples were measured by inductively coupled plasma mass spectrometry (ICP-MS) for their heavy metal content. At 9.09% residue-mixing ratio, chromium and arsenic added into the furnace increased to 1.46 and 1.44 times respectively. The results show that the mass balance coefficients of trace elements studied are 88.3%—96.2% and 75.8%—76.5%, respectively. Under co-processing condition, 92.73% chromium is enriched in fly ash, and chromium in flue gas exists in particles. The distribution of arsenic in fly ash is 49.83%, which is lower than that of chromium. The flue gas desulfurization (FGD) system can capture the arsenic escaped from the electrostatic precipitator. 24.64% of the - arsenic entering furnace is finally fixed in the FGD gypsum, and only 0.008% is still emitted with the flue gas. 87.2% of the flue gas arsenic is in particulate form and 12.8% is in gaseous form. Chromium and arsenic emitted through flue gas meet emission standards issued by the US Environmental Protect Agency. The leaching concentrations of chromium and arsenic of the solid byproducts are lower than the limit of hazardous waste identification standard. Co-processing antibiotic residue in a pulverized coal furnace turns out to be safe and feasible.

Key words: waste treatment, coal combustion, pollution, co-processing, heavy metal, antibiotic residue

摘要：

利用某300MW煤粉锅炉进行了协同处理抗生素药渣试验，研究了掺烧期间Cr、As元素的迁移特性及对环境的影响。收集样品并用电感耦合等离子质谱法分析重金属含量，以9.09%比例掺烧药渣，入炉Cr和As分别增加至1.46倍和1.44倍。Cr和As元素的质量平衡系数分别为88.3%～96.2%和75.8%～76.5%。协同工况下，有92.73% Cr富集在飞灰中，烟气Cr全部为颗粒态，占0.13%；As在飞灰的分布低于Cr，有49.83%被飞灰吸附，烟气脱硫系统能够捕获从电除尘逃逸的As，24.64%的入炉As被固定于脱硫石膏中，有0.008%随烟气排放，烟气As有87.2%为颗粒态，12.8%为气态形式。烟气中的Cr和As浓度达到排放标准，固体产物的Cr、As浸出浓度均低于危废鉴定标准限值，利用煤粉炉协同处置抗生素药渣工艺是安全可行的。

关键词: 废物处理, 煤燃烧, 污染, 协同处理, 重金属, 抗生素药渣