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生物炭具有丰富的孔隙结构和巨大的比表面积,是一种良好的保水材料。为探究沙蒿生物炭保水效果对炭化条件的响应,设置不同的炭化温度、炭化时间和升温速率3个炭化条件,对沙蒿进行无氧炭化,研究各种生物炭的吸水和保水效果。结果表明:生物炭和沙蒿的吸水率均较高,分别为4 246.6~4 803.3g·kg~(-1)和5 340.3g·kg~(-1);600℃的生物炭在去离子水中的保水能力相对较强,其拟合曲线的决定系数为0.963 4~0.986 2,且炭化60min时最大,为0.986 2,沙蒿最小,为0.938 1;在沙土中的蒸发速率分别为自然沙的0.955~0.996倍和0.996倍,600℃炭化60min时最小,炭化5min时最大。而升温速率在生物炭的吸水和保水效果中不起决定作用。因此,生物炭的保水性能主要取决于炭化温度和时间,其吸水和保水性能不具有一致性,而在去离子水和沙土中的保水性能具有一致性;600℃炭化60min的生物炭是提高沙土保水性能的最优选择。
Biochar has a rich pore structure and huge surface area, is a good water retention material. In order to explore the response of the water-holding effect of the Artemisia bracteatum to the carbonization conditions, three carbonization conditions, such as carbonization temperature, carbonization time and heating rate, were set up to carry out anaerobic carbonization of Artemisia selengensis to study the water absorption and water retention effects of various biochar. The results showed that the water absorption rates of biochar and Artemisia selengensis were all high, ranging from 4 246.6 to 4 803.3 g · kg -1 and 5 340.3 g · kg -1, respectively. The biochar at 600 ℃ in deionized water The water retention capacity was relatively strong. The coefficient of determination for the fitted curve was 0.963 4-0.98662, the maximum was 0.986 2 at 60 min carbonization, and the minimum was Artemisia sphaerocephala, 0.938 1. The evaporation rates in sandy soil were respectively natural sand 0.955 ~ 0.996 times and 0.996 times, 600 ℃ carbonization 60min when the smallest, carbonized 5min maximum. The heating rate in biochar water and water retention effect can not play a decisive role. Therefore, the water retention capacity of biochar depends mainly on the carbonization temperature and time, and its water absorption and water retention properties are not consistent, while in the deionized water and sand water retention performance is consistent; 600 ℃ carbonization 60min biochar is to improve sand The best choice of water retention performance.