摘要
【目的】以城市园林废弃物树皮、树枝、树叶和残草为研究对象,采用生物质热解炭化工艺制备生物质炭,分析评价生物质炭的理化性质及用于改善土壤和环境的潜力,为园林废弃物炭化处理及其产物的循环利用提供依据。【方法】运用C、H、O等元素分析和物理分析,Pb、Cd、Cu、Zn等重金属元素含量分析,表面形貌分析及可溶性组分气质联用(GC/MS)分析等方法,表征生物质炭的有机物质组成、颗粒吸附特性、活性有机质丰度以及环境风险物质的存在等。【结果】4种园林废弃物生物质炭的有机碳含量介于46.8%~76.1%之间,树枝类高于草本类20%以上,且热值高达30 MJ·kg^-1;残草和树叶生物质炭N、P、K等养分含量高于树皮和树枝,且孔隙度和比表面积较高;4种园林废弃物生物质炭水溶性有机碳含量介于2.86~31.20 g·kg^-1之间,检测出177种化合物,主要是有机酸,其次是醇类和糖类等。园林废弃物生物质炭的重金属元素含量尽管满足直接农用,但均符合非农地土壤限值。【结论】城市园林废弃物生物质炭有机质丰富,物理结构良好,活性有机组分和养分含量高,环境风险极低,资源化利用潜力突出。木本类生物质炭可用作燃料炭或土壤覆盖吸水材料,树叶和残草生物质炭宜作为土壤改良剂和营养基质利用,且因丰富的可溶性有机-无机养分,有望进一步开发用作园林绿化植物叶面调理剂。
【Objective】This study analyzed biochars pyrolyzed from urban green wastes of wood bark,branch,leaf and grass biomass in a bench pyrolyzer,in order to explore its value for potential application to urban soil and environment improvement in recycling green waste through biomass carbonization.【Method】Physico-chemical,and elemental analysis of carbon and metals as well as nutrients,surface morphology and tomography analysis and proximate analysis of biochar particles,and GC/MS analysis of dissolvable organic matter(DOM)pool of biochars were conducted to characterize the organic composition,particle adsorption capacity and moisture retention,existence of bioactive molecules and potentially toxic metal elements(PTEs)of the biochars.【Result】The organic carbon content of the urban green waste biochars varied from 46.8%to 76.1%.With high thermal value up to 30 MJ·kg^-1,wood bark and branch biochars contained higher organic carbon by over 20%than leaf and grass derived biochars.However,the leaf and grass biochars were rich in N,P and K nutrients,with higher porosity and surface area,than the wood and branch ones.DOM pool of the biochars ranged from 2.86 to 31.20 g·kg^-1,with totally 177 chemical compounds,including organic acid,alcohols and saccharide.Contents of the PTEs were all beyond the guideline limits for organic amendments in agriculture.Concerning the significant content of PTEs,green waste biochars could not directly applied to agricultural soils,but meet the guideline limit for non-agricutural lands.【Conclusion】The biochars from urban green wastes are rich in organic carbon with bioactive molecules,inorganic nutrients and micropores,but limited concentration of PTEs,indicating a great potential utilization use to improve urban soils.Particularly,the bark and branch biochars could be used as biomass fuels or water-absorbing materials,while the leaf and grass derived biochars could be applied as soil conditioner and nutritional growth media for enhancing urban vegetation.Furthermore,the bioactive
作者
鞠艳艳
丁元君
邵前前
张晓春
高红艳
连梦莹
卞荣军
王晓明
潘根兴
Ju Yanyan;Ding Yuanjun;Shao Qianqian;Zhang Xiaochun;Gao Hongyan;Lian Mengying;Bian Rongjun;Wang Xiaoming;Pan Genxing(Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095;Shenzhen-NJAU Center of Green Technology of Urban Biowastes, Shenzhen 518000;Shenzhen Association of Landscape Architecture, Shenzhen 518000)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2020年第8期107-120,共14页
Scientia Silvae Sinicae
基金
城市园林生物质绿色工程技术开发项目(HY-0087)。
