【作者】 梁丰；

【导师】 林启美； 李贵桐； 赵小蓉；

【作者基本信息】 中国农业大学 ， 土壤学， 2014， 博士

【摘要】 生物质炭(Biochar)是新近提出的一项应对温室效应的技术措施,同时也是一项提高土壤肥力的新举措,是当前研究的热点之一。针对生物质炭研究中集中在酸性土壤、短期培养试验、单季田间试验的现状,结合生物质能源生产中催化剂普遍使用的实际情况,本文从普通生物质炭对石灰性土壤性质及作物产量的长期影响出发,通过实验室小型设备,研究催化剂对污泥水热炭化过程和作物秸秆干裂解过程和产物性质的影响,分析催化剂对生物质炭性质的影响,为其进一步农业应用提供实验依据。研究主要结果如下：催化剂可缩短加热水热炭化过程的加热时间9-23%,具有一定的节约能耗效果。催化剂可显著降低水热炭中C、N含量,极大清除污泥伴生污水中的P；CaO可显著提高污泥水热炭的酸缓冲性和pH,催化剂可降低水热炭的炭化度。催化剂可显著降低水热液中C的浓度,显著提高水热液的生化降解性,极大降低P的富营养化风险。水热炭化使分散态重金属集中分布于水热炭、水热液及焦油中,CaO对水热炭中重金属含量和活性的影响高于FeCl3, CaO可提高酸溶态重金属的比例,而FeCl3对7种重金属的活性无明显影响。K2C03或K2CO3/CaO混合物均可降低生物质炭中全C、N的浓度,提高生物质炭中DOC、易矿化态N、交换态P、K的比例,含催化剂的生物质炭中养分的有效性较高。K2CO3或K2CO3/CaO混合物可提高生物质炭的pH和CEC值,降低生物质炭的碘吸附值。K2C03或K2CO3/CaO混合物均可降低生物质炭的炭化程度,表明催化剂降低生物质炭的稳定性,提高其可降解性,较普通生物质炭更具生物驱动作用。三年田间长期试验结果表明,在石灰性砂壤土上施用生物质炭,对冬小麦与夏玉米的年均产量没有显著影响,施用60t ha-1生物质炭是比较适当的用量；生物质炭对土壤速效养分状况的影响不显著,对土壤容重和持水能力具有一定的提高作用。上述研究结果表明,普通生物质炭对石灰性土壤性质及作物产量无不良影响,含催化剂的生物质炭的农学适用性高于普通生物质炭。当然,关于含催化剂的生物质炭的农学性质尚需土壤施用试验来验证。更多还原

【Abstract】 Biochar is a newly emerged technology to cope with the greenhouse effect. It is also a new method to improve soil fertility. Both of the above are one of the hot-topics in today’s scientific research. Most of these researches were focused on acid soil, laboratory incubation experiment, or field experiment of a single growing-season. At the same time, catalysts were widely used in bio-energy production. Based on these facts, two researches were conducted in this study. The first one was the long-term impact of ordinary biochar on soil properties and crop yields in a field experiment running on a calcareous soil, and the second one was a laboratory experiment, focusing on the effect of catalysts on the properties of products of the hydrothermal carbonization of sewage sludge and the pyrolysis of crop straw. The main aim of this study was to provide an experimental basis for the further agricultural application of these catalysts-contained biochar. The main results are listed as followed:The catalysts shortened the heating time of sludge hydrothermal carbonization process from9to23%, meaning saving energy somewhat. The catalysts significantly reduced the content of C and N in the hydrochar, and CaO significantly increased the acid buffer capability and pH of the hydrochar. The catalysts reduced the carbonization degree of the hydrochar. The catalyst significantly reduced the concentration of C in the hydro-liquid, and significantly improved the biochemical degradability of the hydro-liquid. The dispersed heavy metals in original sludge were concentrated in the hydrochar, the hydro-liquid and the tar. The impact of CaO on content and activity of heavy metals in the hydrochar was greater than that of FeCl3. CaO increased the proportion of acid-soluble heavy metals in hydrochar while FeCl3had little effect on the activity of the heavy metals activity.K2CO3or K2CO3/CaO mixture reduced the concentration of total C and N in the biochar, and increased the ratio of DOC, easily mineralized N, exchangeable P and K in the biochar, meaning catalysts could increase the nutrients availability of the biochar. The K2CO3or K2CO3/CaO mixture increased pH and CEC of the biochar, but reduced iodine adsorption of the biochar. K2CO3or K2CO3/CaO mixture reduced the carbonization degree of the biochar, indicating catalysts could reduce the stability of the biochar, improving the degradability of the biochar, thereby improving the bio-driving power of the biochar.Application of biochar to calcareous soil had no significant effect on the average annual yield of winter wheat and summer maize. The most appropriate dosage of biochar was60t ha-1. Biochar applying had little effects on soil available nutrient, but improved the soil bulk density and water holding capacity in this calcareous sandy soil.The above results shows two facts, one is that application of ordinary biochar to calcareous soil has no negative effects both on soil properties and crop yield, and the second is that the agronomic properties of the catalyst-contained biochar is better that that of the ordinary biochar. Of course, the agronomic effects of the catalyst-contained biochar need to be tested by the field experiment.更多还原