Methane emissions during storage of di erent treatments from cattle manure in Tianjin

Many studies on methane emissions from animal manure have revealed that animal manure is a major source of methane emissions to the atmosphere that can have negative consequences for people, animals and environment. In general, the release of methane can be influenced by the type of feed taken by animals, temperature, manure characteristics and so on. This study aimed at quantifying and comparing methane release from dairy manure with di erent piling treatments. Four treatments were designed including manure piling height 30, 45, 60 cm and adding 6 cm manure every day until the piling height was 60 cm. Static chamber method and gas chromatography were adopted to measure the methane emissions from April to June in 2009. Methane emission rates of all four manure treatments were low in the first week and then increased sharply until reaching the peak values. Subsequently, all the methane emission rates decreased and fluctuated within the steady range till the end of the experiment. Wilcoxon nonparametric tests analysis indicated that methane emission rate was greatly influenced by manure piling height and manner. There were no significant relationships between methane emission rates and the temperatures of ambience and heap. However, regression analysis showed that the quadratic equations were found between emission rates of all treatments and the gas temperature in the barrels.     

Influence of season,ventilation strategy,and slurry removal on methane emissions from pig houses

About 60% of the global methane emission is related to anthropogenic activities such as agriculture, fossil fuel use, and waste disposal. A significant part of agricultural methane emissions originates from pig husbandry, with indoor stored pig slurry as the main source. In general, the release of methane from indoor slurry storage can be influenced by availability of oxygen and volatile solids, pH value, substrate temperature, retention time, and presence of inhibiting compounds. Investigations on methane release from a pig house with indoor slurry storage were carried out from October 1999 until February 2001 and from February 2003 until July 2004, respectively. The season, in which the fattening period was accomplished, had a significant influence on the level of the methane emission rate, with increased emissions during summer. However, a clear influence of the indoor temperature – and therefore of the ventilation strategy – on the level of the methane emission rate was only found for mean daily temperatures above 25 °C. Methane emissions were reduced significantly due to complete slurry removal between the fattening periods and subsequent cleaning of the slurry pits.     

Greenhouse gas abatement strategies for animal husbandry

Agriculture contributes significantly to the anthropogenic emissions of non-CO₂ greenhouse gases methane and nitrous oxide. In this paper, a review is presented of the agriculture related sources of methane and nitrous oxide, and of the main strategies for mitigation. The rumen is the most important source of methane production, especially in cattle husbandry. Less, but still substantial, amounts of methane are produced from cattle manures. In pig and poultry husbandry, most methane originates from manures. The main sources of nitrous oxide are: nitrogen fertilisers, land applied animal manure, and urine deposited by grazing animals. Most effective mitigation strategies for methane comprise a source approach, i.e. changing animals’ diets towards greater efficiencies. Methane emissions, however, can also be effectively reduced by optimal use of the gas produced from manures, e.g. for energy production. Frequent and complete manure removal from animal housing, combined with on-farm biogas production is an example of an integrated on-farm solution. Reduced fertiliser nitrogen input, optimal fertiliser form, adding nitrification inhibitors, land drainage management, and reduced land compaction by restricted grazing are the best ways to mitigate nitrous oxide emissions from farm land, whereas, management of bedding material and solid manure reduce nitrous oxide emissions from housing and storage. Other than for methane, mitigation measures for nitrous oxide interact with other important environmental issues, like reduction of nitrate leaching and ammonia emission. Mitigation strategies for reduction of the greenhouse gases should also minimize pollution swapping.     

川中丘陵地区冬水田甲烷排放特征研究

以川中丘陵地区典型冬水田为对象,设置了有水稻常规施肥(RF)、无水稻常规施肥(NP)、有水稻无氮肥(NN)3种处理,以静态暗箱-气相色谱法对甲烷(CH_4)排放进行了原位观测.结果表明,RF、NP和NN处理下CH_4排放通量分别为-0.0042~18.29、0.03~16.78和0.10~26.76mg·m~(-2)·h~(-1),平均排放通量分别为10.22、4.25和14.15 mg·m~(-2)·h~(-1)(以每平方米每小时消耗/产生的C量(mg)计),水稻生长季是主要排放期,但休闲季CH_4排放量仍占全年CH_4总排放量的14%.没有水稻处理的CH_4排放量显著低于有水稻处理(p0.01);而不施氮肥处理的CH_4排放量显著高于施肥处理(p0.01).CH_4排放通量与5 cm深土壤温度呈显著正相关(p0.01),随着温度的升高,甲烷排放量呈指数增加.CH_4排放通量与1~4 cm的稻田水深呈显著负相关(p0.01),随着水深的增加,甲烷的排放呈指数迅速下降;而与4~8 cm的稻田水深无相关性,甲烷的排放也变化缓慢.由此表明,土壤温度和水深在很大程度上调控着CH_4的排放.此外,研究结果也显示将冬水田休闲期改为旱作可减少CH_4排放,对环境有利.     

Greenhouse gas emissions from covered slurry compared with uncovered during storage

Liquid manure storage facilities are sources of methane, nitrous oxide and ammonia emissions. Different materials for covering liquid manure storage facilities to reduce gaseous emissions were investigated on laboratory scale (65 l): perlite (Pegülit™), lightweight expanded clay aggregate (Leca™) and chopped straw—both individually and combined with lactic acid or saccharose, respectively. Methane is the predominant greenhouse gas emitted from liquid manure storage facilities. Nitrous oxide plays a role when surfaces become encrusted when it occurs by using the cover materials investigated. Common cover materials have good reduction effects on ammonia but less on greenhouse gas emissions. Straw can increase emissions of methane and nitrous oxide, as can granules. Lowering the pH value of the slurry can reduce both methane and nitrous oxide emissions. Combinations of covering and acidifying should cause a pH value below 6.0 to reduce methane and nitrous oxide emissions effectively. Lower pH value seems to be necessary also to reduce ammonia emissions effectively.     

黄土及其他添加物对猪粪贮存过程氨气和温室气体排放的影响

畜禽粪肥在贮存阶段养分损失严重,是CO_2、CH_4、NH_3和N_2O等大气污染物的重要排放来源.本文采用室内培养方法,研究了添加黄土、秸秆、生物炭和膨润土对猪粪贮存过程中氨气及温室气体排放的影响.结果表明,添加10%用量的生物炭和膨润土处理的CO_2累积排放量与不添加任何添加物的猪粪对照相比分别降低了15.4%和20.9%,N_2O累积排放量分别降低了19.8%和37.6%.添加膨润土处理的NH_3损失量显著增加,但添加生物炭和膨润土处理的综合温室效应与猪粪对照相比均显著降低.添加10%秸秆处理的CH_4和NH_3累积排放量分别较猪粪对照降低了56.8%和95.8%,但其综合温室效应与对照相比差异不显著.模拟黄土垫圈过程添加黄土处理的氨气及温室气体累积排放量均显著降低,综合温室效应显著低于其他处理(p0.05).可见,黄土垫圈是保蓄粪肥碳、氮养分的有效措施,猪粪贮存阶段添加少量生物炭、膨润土对于减少粪肥综合温室效应具有积极作用.     

Emission of landfill gas in Qingdao, China

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Effect of the chlortetracycline addition method on methane production from the anaerobic digestion of swine wastewater

Effects of antibiotic residues on methane production in anaerobic digestion are commonly studied using the following two antibiotic addition methods：（1） adding manure from animals that consume a diet containing antibiotics, and（2） adding antibiotic-free animal manure spiked with antibiotics. This study used chlortetracycline（CTC） as a model antibiotic to examine the effects of the antibiotic addition method on methane production in anaerobic digestion under two different swine wastewater concentrations（0.55 and 0.22 mg CTC/g dry manure）. The results showed that CTC degradation rate in which manure was directly added at 0.55 mg CTC/g（HSPIKE treatment） was lower than the control values and the rest of the treatment groups. Methane production from the HSPIKEtreatment was reduced（p 〈 0.05） by 12% during the whole experimental period and 15% during the first 7 days. The treatments had no significant effect on the pH and chemical oxygen demand value of the digesters, and the total nitrogen of the0.55 mg CTC/kg manure collected from mediated swine was significantly higher than the other values. Therefore, different methane production under different antibiotic addition methods might be explained by the microbial activity and the concentrations of antibiotic intermediate products and metabolites. Because the primary entry route of veterinary antibiotics into an anaerobic digester is by contaminated animal manure, the most appropriate method for studying antibiotic residue effects on methane production may be using manure from animals that are given a particular antibiotic, rather than adding the antibiotic directly to the anaerobic digester.     

不同施肥模式对热区晚稻水田CH4和N2O排放的影响

由于农田温室气体排放的原位观测主要集中于温带和亚热带地区,热带地区农田土壤温室气体的排放往往被忽视.研究不同施肥模式下海南稻田温室气体排放特征对于准确评估我国农田土壤CH_4和N_2O排放及制定相应的减排措施有重要意义.本研究设置5个处理:空白对照(CK)、常规施肥(CON)、优化施肥(YH)、优化施肥与缓控释肥配施(ZYH1)、优化施肥、缓控释肥和有机肥三者配施(ZYH2),采用静态箱-气相色谱法,通过田间小区试验研究晚稻生长季CH_4和N_2O排放动态特征,并估算全球增温潜势(GWP)以及温室气体排放强度(GHGI).结果表明,CK、CON、YH、ZYH1和ZYH2处理的CH_4晚稻生长季累计排放量分别为175. 70、60. 30、63. 00、62. 80和56. 60 kg·hm~(-2),相应处理的N2O晚稻生长季累积排放量分别为0. 78、3. 40、1. 03、1. 44和0. 44 kg·hm~(-2). ZYH2的产量较CK、CON、YH和ZYH1分别提高了29. 69%、11. 81%、6. 74%和10. 36%,GWP较CK、CON、YH和ZYH1分别降低了64. 80%、43. 23%、12. 93%和15. 15%,同时,GHGI分别降低了76. 49%、52. 52%、20. 54%和23. 87%.相关分析结果表明:土壤温度和Eh是驱动CH_4排放变化的主要因素.综合产量及温室气体减排效果而言,优化施肥+羊粪有机肥+缓控释肥处理(ZYH2)是当地值得推广的减肥模式.     

Greenhouse gas emissions from oilfield-produced water in Shengli Oilfield, Eastern China

Greenhouse gas(GHG) emissions from oil and gas systems are an important component of the GHG emission inventory. To assess the carbon emissions from oilfield-produced water under atmospheric conditions correctly, in situ detection and simulation experiments were developed to study the natural release of GHG into the atmosphere in the Shengli Oilfield,the second largest oilfield in China. The results showed that methane(CH4) and carbon dioxide(CO2) were the primary gases released naturally from the oilfield-produced water.The atmospheric temperature and release time played important roles in determining the CH4 and CO2emissions under atmospheric conditions. Higher temperatures enhanced the carbon emissions. The emissions of both CH4 and CO2from oilfield-produced water were highest at 27°C and lowest at 3°C. The bulk of CH4 and CO2was released from the oilfield-produced water during the first release period, 0–2 hr, for each temperature, with a maximum average emission rate of 0.415 g CH4/(m3·hr) and 3.934 g CO2/(m3·hr), respectively. Then the carbon emissions at other time periods gradually decreased with the extension of time. The higher solubility of CO2 in water than CH4 results in a higher emission rate of CH4 than CO2over the same release duration. The simulation proved that oilfield-produced water is one of the potential emission sources that should be given great attention in oil and gas systems.     

Effect of straw addition on nitrous oxide and methane emissions from stored farmyard manures

Stored solid manure heaps can be a significant source of nitrous oxide (N₂O) and methane (CH₄) emissions. The manure characteristics influence emissions and solid manure heaps can be managed to promote aerobic decomposition during storage. Increasing the carbon (C) content of the manure heap with high-C additives, such as straw, may provide the opportunity for N₂O and CH₄ emission reduction. Greenhouse gas (GHG) emissions from conventionally produced farmyard manure (FYM) have been quantified, but there is little data on emissions from organically produced FYM. N₂O and CH₄ emissions were measured using a small-scale storage method from FYM collected from organic and conventional dairy units under a range of storage conditions with and without extra straw addition.The organic and the conventional FYM were similar in composition except for the higher C and dry matter content in the organic FYM and in the FYM with added straw. This resulted in mean total emissions of N₂O and CH₄ being lower from the organic (27 g N t⁻¹) than the conventional FYM (52 g N t⁻¹) and from the treatments with straw added (32 g N t⁻¹) than those without (47 g N t⁻¹). The initial C:N ratio and dry matter content of the stored FYM were the most important factors affecting N₂O and CH₄ emissions although the FYM temperature also affected CH₄ emissions. Adding high-C additives, such as straw could be a promising strategy for reducing GHG emissions because it influences the dry matter content, C:N ratio and aeration of the manure. The small-scale FYM storage method were shown to be a reliable and an easy method to quantify emissions under a range of environmental conditions and manure manipulations and so develop effective manure management practices to reduce GHG emissions.     

广东省人为源氨排放清单及减排潜力研究

根据各类氨排放源活动水平数据,采用排放因子法,建立了2010年广东省人为源氨排放清单,在分析其排放特征的基础上探讨了氨的减排潜力.结果表明:2010年广东省人为源氨排放量为582.9 kt,畜禽和氮肥施用是排放贡献最大的人为源,分别占总排放量的44.2%和40.4%;茂名、湛江和肇庆依次是排放量最大的3个城市,共占广东省总排放量33.0%;在畜禽源中,肉猪排放量最大,占畜禽源排放总量44.4%,其次是肉鸡、母猪和黄牛,分别占16.0%、15.2%和6.5%;畜禽在畜舍、储存管理、农田施肥和放牧4个养殖阶段的氨排放量不同;控制农业源对NH3的减排起关键性作用,茂名、湛江和肇庆是广东省重点控制的3个城市,肉猪、母猪、肉鸡、黄牛和氮肥施用则为重点控制源,主要控制措施包括低氮饲料喂养、畜舍改造、粪便密封、粪肥注施、延长放牧时间和使用尿素替代物.     

Factors Affecting Future Emissions of Methane from Non Land Use Sources

Evidence from the atmosphere indicates that global emissions of methane may have been broadly constant since the early 1980s or growing only slowly. This suggests that whilst emissions from some sources may have increased with increased activity, emissions from other sources may have gone down. This is supported by evidence and analysis from the individual emission sectors which show declining emission rates in some cases. This paper reviews the factors that might affect emissions in the future from different sources and has been written as an aid to the development of new scenarios for greenhouse gas emission for the Intergovernmental Panel on Climate Change. The analysis indicates that there could be additional uncertainty in future emissions but that, overall, future emissions might plausibly be lower than previously projected.     

猪粪堆肥过程保氮固磷及温室气体（N2O）减排研究

针对畜禽粪便堆肥过程存在的氮素流失与温室气体（N2O）排放及畜禽粪便堆肥产品土地利用过程的磷素流失等不足,采用强制通风反应器堆肥系统进行小试规模的猪粪堆肥试验,以改性赤泥和改性镁橄榄石为添加剂,考察和比较了这2种改性金属盐添加剂在猪粪堆肥过程对氮磷保存与温室气体（N2O）减排的效果.结果表明,添加改性镁橄榄石（pH=7...     

中国动物源CH_4排放空间分布和时间变化研究

将IPCC国家温室气体清单指南（2006）用于估算动物源CH4排放的方法2和GIS空间化数据库技术结合,以2004年全国各县级行政单位的畜牧统计数据和1 km×1 km土地利用栅格数据为主要数据源,系统地估算了中国大陆当年动物源CH4排放量（包括消化道CH4排放和粪便管理系统CH4排放两部分）,并分析了其空间分布和季节...     

施用畜禽粪便堆肥品的蔬菜地CH4、N2O和NH3排放特征

农田是重要的温室气体排放来源之一,其中蔬菜地的温室气体排放日益受到人们关注.以北京市郊某温室种植的油麦菜地为研究对象,通过大棚试验,考察和比较了油麦菜地施用不同类型畜禽粪便堆肥产品的CH4、N2O和NH3排放特征及其影响因素.结果表明,油麦菜地NRM、RM、CF处理的CH4排放系数分别为0.2%、0.027%、0.004%;N2O排放系数分别为0.18%、0.63%、0.74%;NH3排放系数分别为2.00%、3.98%、2.53%.CH4排放通量与土壤温度和地表湿度相关,N2O排放通量与土壤温度、地表温度和湿度相关,CH4、N2O和NH3排放通量均受土壤含水率影响,而温室中的气温不是影响CH4、N2O和NH3排放的主要因素.     

地下水位和土壤温度对若尔盖泥炭地CH4排放的影响

为了深入分析环境因子对湿地CH₄排放产生的影响,利用中型试验生态系对若尔盖典型泥炭地开展地下水位和土壤温度控制试验,比较不同条件下泥炭地2012年生长季(5—10月)CH₄排放通量的月变化情况. 结果表明:高水位(土壤表面0 cm)下CH₄排放通量最高,中水位(地表以下10 cm)下次之,低水位(地表以下20 cm)下最低;其中,10月CH₄排放通量变化不明显,不同地下水位下泥炭地的CH₄排放通量均在7月达到最大值,并且均呈明显的单峰曲线,高、中、低地下水位下CH₄排放通量平均值分别为6.263 3、4.754 4和3.949 8 mg/(m2·h). 而且,在一定温度范围内,不同地下水位条件下CH₄排放通量随土壤温度的升高均呈指数式增长. 其中,高水位下CH₄排放通量对土壤温度变化最为敏感,中水位下次之,低水位下相对最不敏感. 研究显示,若尔盖泥炭地CH₄排放通量表现出明显的季节性变化差异,并且季节性升温和涨水均会促进CH₄排放通量的增加.      

典型炼化企业温室气体甲烷排放特征

温室气体排放是造成全球变暖和气候恶化的重要根源.甲烷是仅次于二氧化碳的温室气体组分.石油加工过程是潜在的甲烷排放源.本文以我国广西某炼化企业为样本,通过现场采样和离线分析的方法,识别出炼化企业潜在的甲烷排放源,核算了不同排放源的甲烷排放量,分析了炼化企业的甲烷排放特征.研究表明,甲烷是炼化企业排放废气中的重要成分;烟气、污水收集和处理系统、储罐和油品装卸过程等均是重要的甲烷排放源项,其中烟气和储罐对甲烷排放总量贡献占比超过70%;不同源项甲烷排放特征各异,油品装载过程产生废气甲烷浓度最高;污水处理过程废气的甲烷浓度主要受常减压装置污水影响;该炼化企业每万吨原油对应的甲烷排放速率估算值为72.6 kg.     

2015年中国地区大气甲烷排放估计及空间分布

CH₄是仅次于CO₂的重要温室气体,也是重要的化学活性气体.定量估算我国甲烷的排放量及分析其空间分布特征,对于控制温室气体排放,减缓温室效应具有重要意义.本文以2015年中国官方统计年鉴资料为基础,利用IPCC排放清单指南、国内外排放因子研究结果及动力学模型方法,从能源活动（煤炭开采和油气系统）、农业活动（反刍动物、稻田排放和秸秆露天燃烧）、自然源排放（自然湿地和植被排放）、废弃物处理（固体废弃物、工业污水和生活污水）和人工湿地等几个主要方面,对中国地区的CH₄排放进行定量估计.结果表明：中国地区2015年CH₄排放总量为61.59 Tg,其中以农业活动和能源活动为主要排放源,排放量分别达到20.42 Tg和20.39 Tg,占总排放量比例分别约为33.2%和33.1%.CH₄自然源考虑了植被和自然湿地排放,排放量为11.77 Tg,占比为19.1%;废弃物处理产生的CH₄排放量为8.64 Tg,占比为14.0%;人工湿地排放量为0.37 Tg,占比为0.6%.从空间分布来看,CH₄排放具有较明显的不均匀性,大值区主要集中在华北、西南及东南地区,而西北地区的排放量则相对较低,主要与各地的资源环境、人口密度和经济情况密切相关.     

Cover crop effects on nitrous oxide emission from a manure-treated Mollisol

Agriculture contributes 40–60% of the total annual N₂O emissions to the atmosphere. Development of management practices to reduce these emissions would have a significant impact on greenhouse gas levels. Non-leguminous cover crops are efficient scavengers of residual soil NO₃, thereby reducing leaching losses. However, the effect of a grass cover crop on N₂O emissions from soil receiving liquid swine manure has not been evaluated. This study investigated: (i) the temporal patterns of N₂O emissions following addition of swine manure slurry in a laboratory setting under fluctuating soil moisture regimes; (ii) assessed the potential of a rye (Secale cereale L.) cover crop to decrease N₂O emissions under these conditions; and (iii) quantified field N₂O emissions in response to either spring applied urea ammonium nitrate (UAN) or different rates of fall-applied liquid swine manure, in the presence or absence of a rye/oat winter cover crop. Laboratory experiments investigating cover crop effects N₂O emissions were performed in a controlled environment chamber programmed for a 14 h light period, 18 °C day temperature, and 15 °C night temperature. Treatments with or without a living rye cover crop were treated with either: (i) no manure; (ii) a phosphorus-based manure application rate (low manure): or (iii) a nitrogen-based manure application rate (high manure). We observed a significant reduction in N₂O emissions in the presence of the rye cover crop. Field experiments were performed on a fine-loamy soil in Central Iowa from October 12, 2005 to October 2, 2006. We observed no significant effect of the cover crop on cumulative N₂O emissions in the field. The primary factor influencing N₂O emission was N application rate, regardless of form or timing. The response of N₂O emission to N additions was non-linear, with progressively more N₂O emitted with increasing N application. These results indicate that while cover crops have the potential to reduce N₂O emissions, N application rate may be the overriding factor.