摘要
为探究锯末、园林废弃物和玉米秸秆在相同覆盖质量(650g)下对奶牛场黑膜沼气池发酵产生的沼液贮存过程中污染气体排放的影响,采用动态箱法测试了3种材料覆盖下沼液的氨气(NH_(3))、硫化氢(H_(2)S)、氧化亚氮(N_(2)O)、甲烷(CH_(4))和二氧化碳(CO_(2))的排放量.结果表明,与不覆盖处理相比,覆盖对NH_(3)有明显的减排效果,但N_(2)O、CH_(4)、CO_(2)和H_(2)S的排放量有所增加,从而提高了综合温室效应.总CO_(2)排放当量增幅为:园林废弃物(26.0%)>玉米秸秆(24.7%)>锯末(12.9%).从微生物群落结构来看,覆盖处理抑制了具有化能异养、好氧化能异养、硝酸盐氨化、硝酸盐还原、亚硝酸盐呼吸和硝酸盐呼吸等功能的微生物活性,降低了沼液内部的碳、氮、硫循环强度.与园林废弃物和玉米秸秆相比,锯末覆盖明显降低了沼液内部拟杆菌科(Bacteroidaceae)和紫单胞菌科(Porphyromonadaceae)等细菌的相对丰度,对沼液内部的碳、氮循环抑制作用最大,更好地减弱了沼液内部的有机质分解和污染气体产生.然而,覆盖下的沼液总CO_(2)排放当量却有所增加,这可能是由于材料覆盖厚度较小,导致覆盖的生物质材料腐解对气体排放的贡献大于覆盖材料对气体产生的抑制作用和对气体排放的阻挡、吸附作用.基于上述研究,锯末覆盖材料最难分解以致总CO_(2)当量增加最少,且形成的隔层对沼液内部碳、氮循环的抑制作用最强,表现出较好的温室气体减排潜力.因此,应进一步研究更高厚度的锯末材料覆盖沼液对气体排放的影响,确定合适的覆盖参数,以实现沼液贮存过程中的污染气体减排.
This study aimed to investigate the effects of sawdust,garden waste,and corn straw as covering materials on gaseous emissions during biogas slurry storage at the same weight of 650g.The emission of ammonia(NH_(3)),hydrogen sulfide(H_(2)S),nitrous oxide(N_(2)O),methane(CH_(4)),and carbon dioxide(CO_(2))from biogas slurry were measured by the dynamic chamber method.The results showed that mulching significantly reduced the emission of NH_(3),but increased the emissions of N_(2)O,CH_(4),CO_(2) and H_(2)S,thus increasing the total CO_(2) equivalent.The order of such increase followeds:garden waste(26.0%)>corn straw(24.7%)>sawdust 1(12.9%).Microbial analysis indicated that,mulching treatment inhibited the activity of microorganisms for chemoenergetic heterotrophy,anabolic heterotrophy,nitrate ammonification,nitrate reduction,nitrite respiration and nitrate respiration,thus reducing the intensity of carbon,nitrogen and sulfur cycles.Compared to garden waste and corn straw,sawdust mulching significantly reduced the relative abundance of bacteria such as Bacteroidaceae and Porphyromonadaceae to restrain carbon and nitrogen cycles for the reduction of organic decomposition and thus gaseous emissions inside biogas slurry.It is noteworthy that biomass coverage increased the cumulative emission of greenhouse gases,possibly due to the decomposition of organic substances in covering materials to overcome their performance for the blockage of gaseous emissions from biogas slurry.Of the three materials,sawdust was recalcitrant to biodegradation and thus led to lowest cumulative emission of greenhouse gases.Furthermore,sawdust facilitated the formation of a tough cake layer on the surface of biogas slurry to inhibit carbon and nitrogen cycles for gaseous emissions.Therefore,sawdust is highly recommended as the biomass material to mitigate gaseous emissions in biogas slurry storage.Nevertheless,further investigation is still needed to optimize sawdust thickness as a coverage in the management of biogas slurry storage.
作者
魏佳欣
亓传仁
刘婉岑
罗文海
李国学
张智烨
WEI Jia-xin;QI Chuan-ren;LIU Wan-cen;LUO Wen-hai;LI Guo-xue;ZHANG Zhi-ye(Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation,Key Laboratory of Low-carbon Green Agriculture,Ministry of Agriculture and Rural Affairs,P.R.China,College of Resource and Environmental Sciences,China Agricultural University,Beijing 100193,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第4期1744-1756,共13页
China Environmental Science
基金
内蒙古自治区科技计划项目(2021GG0316)
中国科学技术协会青年人才托举工程项目(YESS20200124)
海南省重大科技计划项目(ZDKJ2021009-1)
三亚崖州湾科技城管理局资助项目(SYND-2021-09)
中国农业大学2115人才工程资助。
