【作者】 陈伟；

【导师】 廖新俤；

【作者基本信息】 华南农业大学 ， 动物营养与饲料科学， 2016， 硕士

【摘要】 堆肥是畜禽粪便无害化处理与资源化利用的重要手段,然而在堆肥过程中存在着多种有害气体释放造成二次污染。本文以降低蛋鸡粪堆肥过程的氨气与甲烷排放为目的,进行生物炭的优选及改性,以期得到一种能高效减排蛋鸡粪堆肥过程氨气和甲烷排放的生物炭产品,并结合堆肥样品理化指标和微生物学指标初步探讨了生物炭对堆肥氨气和甲烷减排的机制,为生产中有效降低堆肥过程有害气体排放提供技术支撑和理论依据。试验包括三个部分:一是不同生物炭对蛋鸡粪堆肥过程氨气和甲烷减排的研究;二是生物炭的改性与优选;三是改性生物炭对蛋鸡粪堆肥氨气和甲烷减排效应及机理。主要研究结果如下:（1）与空白组相比,堆肥期间添加秸秆炭、竹炭、木炭、椰壳炭、鸡粪炭后堆肥中氨气总排放量分别降低了33.11%、22.70%、32.87%、21.51%和24.19%,其中,生物炭添加组氨气总排放量显著低于空白组,秸秆炭组与木炭组氨气总排放量显著低于其他生物炭组（P<0.05）;各生物炭添加组甲烷总排放量与空白组相比分别降低了22.17%、12.14%、17.72%、6.12%和14.31%,秸秆炭组、木炭组和椰壳炭组甲烷总排放量显著低于空白组（P<0.05）。此外,添加秸秆炭还能提高堆肥温度与物料硝态氮含量,降低铵态氮含量与堆肥pH,促进有机质降解。这可能与其具有更大的比表面积和孔体积以及丰富的表面官能团相关。因此,本文选择秸秆炭为研究对象,通过进一步改性,以期提高堆肥中氨气和甲烷排放的效果。（2）6 mol/L、8 mol/L、10 mol/L HNO3改性炭的氨氮吸附量显著大于其他HNO3改性炭和未改性秸秆炭（P<0.05）;25%和30%改性炭的氨氮吸附量显著大于其他双氧水改性炭（P<0.05）;先后经6 mol/L HNO₃和25%H₂O₂改性制备的混合改性炭的氨氮吸附量显著高于6 mol/L HNO₃改性炭（P<0.05）,但与25%H₂O₂改性炭无显著差异（P>0.05）。表面理化性质分析表明:与25%H₂O₂改性炭和6 mol/L HNO₃改性炭相比,混合改性炭具有较大的比表面积、总孔体积及较多的表面酸性官能团数量（P<0.05）。基于改性炭的氨氮吸附量和表面化学性质,选取25%H₂O₂改性炭和混合改性炭进行模拟堆肥试验。（3）与空白组相比,添加秸秆炭、H₂O₂改性炭组和混合改性炭组氨气总排放量分别减少27.59%、15.20%和41.07%,混合改性炭组氨气总排放量显著低于秸秆炭组（P<0.05）。与秸秆炭相比,混合改性炭添加降低了堆体pH,促进了有机质降解,进一步降低了堆肥氮素损失。添加秸秆炭、H₂O₂改性炭组和混合改性炭组甲烷总排放量分别减少14.10%、14.91%和15.54%,添加改性生物炭并没有进一步降低堆肥甲烷总排放量。添加混合改性炭提高了堆肥中细菌的多样性,改变了细菌群落结构,提高了物料中硝化细菌的平均相对丰度,降低了反硝化细菌和产甲烷菌平均相对丰度。综上所述,在本试验中,相比与其他生物炭,秸秆炭和木炭具有显著的有害气体减排潜势,先后经6 mol/L HNO₃和25%H₂O₂混合改性的秸秆炭有利于进一步提高堆肥产品质量和减少有害气体排放。更多还原

【Abstract】 Aerobic composting is an effective way to harmless and recycle animal manure. However, the by-products harmful gases such as ammonia（NH₃） and methane（CH₄） emissions had been paied more attention because it can reduce the quality of compost products and increase the greenhouse effect. As a bulking agent in the composting, biochar is an inexpensive and stabilized resource that can reduce gas emission. But different biochars may have different effects on reducing gas emission. No research had been conducted on it. This thesis study the effect of biochar on NH₃ and CH₄ emission in the layer manure composting based on the five different biochars selection and modification, and discuss the mechanism of the biochar on NH₃ and CH₄ emissions. It might provide a theoretical basis on reducing gases emissions in layer manure composting.This study include three parts: first is the effect of different types of biochars on NH₃ and CH₄ emission during layer manure composting; second is the modification of cornstalk biochar; third is the effect of modified biochars on NH₃ and CH₄ emission during layer manure composting. The main result are as follow:（1） The result show that the total NH₃ production significantly decreased（P<0.05）for the treatments with biochars. Among the biochar treatments, cornstalk biochar and woody biochar were the most effective in mitigating NH₃ productions with reduceing the total NH₃ production by 38.50% and 32.87%, respectively. Cornstalk biochar, woody biochar and coir biochar were significantly ruduce the CH₄ emission（P<0.05） with reduceing the total CH₄ emission by 22.17%, 17.72% and 14.31%, respectively. Moreover, adding cornstalk biochar could increase temperature, NO^3--N concentration and decrease p H, NH⁴⁺-N and organic matter conten throughout the composting process. It might be attributed by the higher posity, surface aera and the more surface functional groups of cornstalk biochar.（2） The adsorption capacity for ammonia nitrogen of modified biocahr by 6, 8, 10 mol/L HNO₃（1.43±0.0052 mg/g, 1.42±0.014 mg/g, 1.43±0.0090 mg/g） were significantly higher than 2, 4 mol/L HNO₃（P<0.05）. The adsorption capacity for ammonia nitrogen of modified biocahr by 25% and 30% H₂O₂（1.57±0.010 mg/g, 1.58±0.010 mg/g） were significantly higher than 10%、15%、20% H2O（0.43±0.019 mg/g, 0.85±0.012 mg/g, 1.20±0.0071 mg/g）（P<0.05）. The adsorption capacity for ammonia nitrogen of biocahr modified by 6 mol/L HNO3 and 25 % H₂O₂（mixed modification） can reach 1.56±0.014 mg/g, significantly higher than 6 mol/L HNO₃ modified biochar（P<0.05）. The number of surface functional groups, the surface aera and pore volumes of mixing modified biochar was significantly higher than 25% H₂O₂ or 6 mol/L HNO₃ modified biochar.（3） The results showed that the cornstalk biochar, H₂O₂ modified biochar and mixing modified biochar treatment can reduce the total NH₃ by 23.73%, 15.20% and 41.07%, respectively. The total ammonia emission in mixed modified biochar treatment was significantly lower than other treatments（P<0.05）. Mixed modified biochar treatment also had significantly lower p H and nitrogen loss, higher organic matter degradation rate during layer manure composting. Mixing modified biochar can improve the mean relative abundance of nitrifying bacteria, decrease the mean relative abundance of denitrifying bacteria and methane-producing banteria.In summary, adding mixing modified biochar can reduce ammonia and methane emission by 41.07% and 15.54% during layer manure composting, improve the quality of composts and reduce environmental pollution.更多还原