發(fā)布時間：2018-03-25 13:10

  本文選題：生物炭　切入點：凍融循環(huán)　出處：《農(nóng)業(yè)環(huán)境科學學報》2017年03期

【摘要】：為了解凍融循環(huán)(模擬物理老化過程)對不同熱解溫度下的牦牛糞生物炭吸附氨氮的影響,通過吸附實驗,考查牦牛糞生物炭老化前后對氨氮的吸附特性,并采用元素分析、掃描電鏡、FTIR、BET-N2等方法分析牦牛糞生物炭的組成及表面結(jié)構(gòu)特性,探討凍融循環(huán)對牦牛糞生物炭吸附氨氮的影響機理。結(jié)果表明,牦牛糞生物炭老化前后對氨氮的吸附動力學模型符合準二級動力學,吸附等溫模型較符合Freundlich模型。不同熱解溫度的牦牛糞生物炭對氨氮的吸附作用存在顯著性差異,凍融循環(huán)作用對熱解溫度較高的牦牛糞生物炭影響較顯著(C020 mg·L~(-1)),氨氮初始濃度為5 mg·L~(-1)時,老化后的生物炭PBC450和PBC600(熱解溫度分別為450℃和600℃)的吸附量比老化前分別顯著提高13.1%、12.4%,去除效率分別為62.6%、55%。PBC450和PBC600的陽離子交換量和比表面積比老化前顯著增加,陽離子交換量分別增加9.1%和75.7%,pH值、Zeta電位顯著降低,其中陽離子交換量和比表面積是影響牦牛糞生物炭吸附氨氮的主要因素。
[Abstract]:In order to understand the effect of freezing and thawing cycle (simulating physical aging process) on the adsorption of ammonia nitrogen by yak manure biochar at different pyrolysis temperatures, the adsorption characteristics of ammonia nitrogen in yak manure biochar before and after aging were investigated by elemental analysis. The composition and surface structure of biochar in yak manure were analyzed by SEM FTIR BET-N2, and the mechanism of freezing and thawing cycle on the adsorption of ammonia nitrogen in yak dung biochar was discussed. The adsorption kinetics model of ammonia-nitrogen in yak manure biochar before and after aging accorded with quasi-second-order kinetics, and the adsorption isothermal model was more in line with Freundlich model. There was significant difference in the adsorption of ammonia-nitrogen between yak fecal biochar with different pyrolysis temperature. The effect of freeze-thaw cycle on the biochar of yak feces with high pyrolysis temperature was more significant when the initial concentration of ammonia nitrogen was 5 mg / L, and the initial concentration of ammonia was 5 mg / L. After aging, the adsorption capacity of PBC450 and PBC600 (pyrolysis temperature was 450 鈩，

本文編號：1663263