云南省昭通市燃煤中氟的释放规律及其环境效应研究

Mechanism of fluorine releasing in coal and day and its effects on environment in Zhaotong, Yunnan Province

目的 探讨燃煤污染型氟中毒病区燃煤中氟的实际燃烧释放规律及其环境效应.方法 在云南省昭通市采集24户农户家的煤、拌煤粘土、煤泥、煤渣以及烘烤前后玉米样品,采用高温燃烧-氟离子选择电极法分析样品中氟含量,计算煤泥氟的燃烧释放量及释放率,并分析煤泥中氟释放量与烘烤玉米中氟增加量的关系.结果 拌煤粘土中氟含量的中位数为1 087.1 mg/kg,范围为266.4～2 536.7 mg/kg;煤泥中氟含量的中位数为308.8 mg/kg,范围为115.9～ 635.0 mg/kg;煤泥燃烧氟释放量的中位数为248.2 mg/kg,范围为63.5～432.2 mg/kg,燃烧释放率的平均值为73.8％,范围为30.3％～91.5％.新鲜玉米中氟含量的中位数为1.31mg/kg,范围为0.43～ 2.00 mg/kg;烘烤玉米中氟含量的中位数为10.49 mg/kg,范围为2.21～44.88 mg/kg,玉米烘烤后氟增加量范围为0.90～44.46 mg/kg.拌煤粘土中的氟含量与煤泥燃烧氟释放量呈正相关（r=0.714,P＜ 0.01）;煤泥燃烧氟释放量与烘烤前后玉米氟增加量未见相关（r=-0.155,P＞0.05）.结论 粘土是燃煤中氟污染物释放的重要来源.烘烤玉米中氟污染程度不是由煤泥中氟释放量所单独决定的,可能还受到多种因素的影响.

Objective To study the real releasing of fluorine （F） and its effects on environmen in coalburning-borne fluorosis areas.Methods The coal,clay,briquette,cinder,fresh corn and roasted corn samples from 24 households were collected systematically in Zhaotong of City,Yunnan Province,and the F concentration in all samples was measured using the combustion hydrolysis/fluoride-ion selective electrode method,and the released amount and rate of F in briquette was calculated,and the relation between the released amount of F from briquette and the increase of F in roasted corn was analyzed.Results The F concentration of clay ranged from 266.4 to 2 536.7 mg/kg with a median of 1 087.1 mg/kg;the F concentration of briquette ranged from 115.9 to 635.0 mg/kg with a median of 308.8 mg/kg.The released amount of F in briquette ranged from 63.5 to 432.2 mg/kg with a median of 248.2 mg/kg.The releasing rate of F in briquette ranged from 30.3% to 91.5% with a average of 73.8%.The F concentration in fresh corn ranged from 0.43 to 2.00 mg/kg with a median of 1.31 mg/kg;the F concentration in roasted corn ranged from 2.21 to 44.88 mg/kg with a median of 10.49 mg/kg.The increased amount of roasted corn ranged 0.90 to 44.46 mg/kg.There was a significant correlation between the emission amounts of F from briquette and the F concentration in binder clay （r =0.714,P 〈 0.01）,but no correlation between the released amount of F from briquette and the increasing of F in roasted corn （r =-0.155,P 〉 0.05）.Conclusion The clay is an important source of F pollution,and the F increase in roasted corn is not only determined by the released amount of F in briquette,but also by several factors.