研究报告

  • 王晓洁,陈冠虹,张仁铎.不同热解温度的生物炭在土壤中的矿化作用研究[J].环境科学学报,2018,38(1):320-327

  • 不同热解温度的生物炭在土壤中的矿化作用研究
  • Mineralization of biochars pyrolyzed under different temperatures in soil
  • 基金项目:国家自然科学基金(No.41471181,51179212)
  • 作者
  • 单位
  • 王晓洁
  • 中山大学环境科学与工程学院, 广州 510275
  • 陈冠虹
  • 中山大学环境科学与工程学院, 广州 510275
  • 张仁铎
  • 中山大学环境科学与工程学院, 广州 510275
  • 摘要:为探究不同热解温度的生物炭不同组分(易降解和相对难降解碳)对其在土壤中矿化作用的影响及机理,将生物质甘蔗渣和在300、500、800℃下热解生成的生物炭(分别表示为BC300、BC500、BC800)通过水洗法剥离出碳骨架部分,然后加入含有定量土壤菌悬液的石英砂中,设置了50 d的控温培养实验并测定培养过程中不同处理样品的矿化速率.结果表明,随着热解温度从300℃升高至800℃,生物炭的易降解碳含量降低,平均停留时间从2 d增加到38 d,相对难降解碳平均停留时间从14年增加到700多年.环境温度为25℃时,碳骨架中由于缺少微生物可利用的溶解性有机碳,所以在土壤中稳定性强.环境温度升高至35℃时,温度升高提高了微生物活性,增加了碳骨架的微生物可利用部分.800℃热解生成的生物炭(BC800)及其碳骨架(W800)的累积矿化量比空白低,且即使温度升高,W800的相对难降解碳含量仍然保持最高,表明高温生物炭具有更好的固碳效果.
  • Abstract:The aim of this study was to investigate the effect of different components (i.e., degradable and relatively refractory carbon pools) of biochars pyrolyzed under different temperatures on mineralization in soil and possible mechanisms. Biomass bagasse and biochars produced using bagasse under pyrolysis temperatures of 300, 500 and 800℃, respectively, were washed to obtain carbon skeletons. Then the carbon skeletons were added to a mixture of soil microbial suspension and quartz sand. Incubation experiments were conducted for 50 d and mineralization rates of the different treatments were measured. Results showed that with increase of the pyrolysis temperatures from 300 to 800℃, the content of biodegradable carbon pools decreased and the average turn over time of the carbon pools increased from 2 to 38 d. The average turn over time of relatively refractory carbon pools increased from 14 to 700 years with increase of the pyrolysis temperatures. Under the ambient temperature of 25℃, the carbon skeletons were very stable in the soil attributable to lacking of soluble organic carbon available for microorganisms. Under the ambient temperature of 35℃, the higher temperature enhanced the microbial activity and the portion of the carbon skeleton available for microorganisms. The cumulative mineralization amount of the treatments with biochar pyrolized under 800℃ and its carbon skeleton was lower than that of the control. With increase of the ambient temperature, the relatively refractory carbon content of the treatment with carbon skeleton at 800℃ remained the highest among the treatments. These results indicate that biochars pyrolyzed under higher temperatures have greater potential of carbon sequestration in soil.

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