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不同用量竹炭对污泥堆肥过程温室气体排放的影响
来源: | 作者:bgdhzc | 发布时间: 2018-09-28 | 752 次浏览 | 🔊 点击朗读正文 ❚❚ ▶ | 分享到:

4产生[12, 26].

2.3 CO2排放特征

堆肥前2 d, 温度适宜, 微生物活动强烈, 有机物大量分解, 堆体CO2排放速率立即达到最大, CK、S1、S2和S3处理分别为24.22、18.08、25.04和15.87 g·(m2·h)-1(图 4).随着堆肥时间的延长, 堆体持续高温, 易降解的有机物浓度急剧下降, 中温微生物大量失活甚至死亡[25], CO2排放速率显著降低.降温腐熟期, 中温微生物继续分解堆体残余有机物, CO2排放速率维持在较稳定的低水平状态.

图 4 CO2排放通量和累积排放量Fig. 4 Fluxes and accumulative emissions of CO2

CK、S1、S2和S3处理CO2累积排放量分别为3.56、3.08、3.44和3.27 kg·m-2(图 4), CO2排放主要集中在堆肥前3周, 占总排放量的75.65%~86.58%, 这是因为堆肥初期有机物充足且微生物活动强烈.与CK相比, 试验组CO2排放量分别降低了13.48%、3.37%和8.15%, 表明添加竹炭堆肥在一定程度上减少堆体CO2排放, 但各处理CO2排放量无显著差异(P＞0.05).陶金沙等[21]添加小麦秸秆生物质炭进行猪粪堆肥, 结果显示猪粪与生物质炭的比例分别为5:1和2.3:1时, CO2排放总量较对照处理显著降低了20.21%和41.10%, 且添加量越多, 其CO2排放量越少; 严慧霞[27]研究也发现添加生物质炭能降低堆体CO2的排放速率.而Mukherjee等[28]认为生物质炭的多孔性可以提高堆体O2供应, 促进好氧微生物分解有机物而产生CO2; 同时, 生物质炭可促进矿化易分解碳向CO2转化, 从而增加CO2排放, 与本研究略有差异.这可能是由于竹炭中含有较多的稳定态有机化合物, 难以被微生物降解, 同时, 竹炭自身含有大量碳素, 能固定堆体部分CO2, 降低堆体微生物的可利用性碳源[21].另一方面, 竹炭比表面积大, 吸附能力强, 能吸附某些微生物或酶, 使其失活或钝化, 抑制堆体CO2产生[29].

2.4 N2O排放特征

堆体N2O排放主要集中在升温期和降温腐熟期(图 5).堆体形成后, 立即产生并排放大量N2O, CK、S1、S2和S3处理分别为21.86、19.85、13.01和11.04 mg·(m2·h)-1.随后2周, N2O排放通量持续下降并保持低水平状态. 3周后, N2O排放通量又显著增加.堆肥初期, 部分物料处于缺氧和厌氧状态, 在反硝化作用下产生大量N2O, 并随着温度的增加而不断逸出.此后, 高温高碱性环境改变了反硝化菌群的丰富度, 氮素代谢受到抑制[30], 堆体N2O排放通量急剧下降.但由于堆肥表面氧气充足, 温度湿度适宜, 硝化细菌可继续发挥硝化作用; 同时, 堆体内存在局部厌氧区域, 反硝化细菌能将NOx--N转化成N2O[31], 再加上升温期残留的N2O, 因此高温期堆体N2O仍有排放且保持低水平排放速率.腐熟期, 堆体温度降低, 堆体内部氧气分布不均, 微生物同时发生好氧硝化和厌氧反硝化作用, 堆体N2O排放通量增加.

图 5 N2O排放通量和累积排放量Fig. 5 Fluxes and accumulative emissions of N2O

堆肥前25 d, N2O累积排放量较小(图 5), 25 d后, N2O排放量显著上升.堆肥后期, 堆体供氧能力增强, 氧化还原电位升高, NO3--N和NO2--N含量增加, 促进N2O产生[32]; 再加上降温腐熟期持续时间长, 因此N2O排放总量较大. CK、S1、S2和S3处理N2O排放量分别为1.71、1.43、1.27和1.00g·m-2, 各处理间存在显著差异(P＜0.05).与CK相比, S1、S2和S3处理分别减少了16.37%、25.73%和41.52%, 表明添加竹炭会显著减少堆体N2O的排放, 且竹炭添加量越多, 堆体N2O排放量越少.这可能是由于竹炭能增强堆体的通气供氧能力, 改善堆体内的厌氧环境, 抑制反硝化作用; 同时, 还能吸附一定量的NH3、NH4+和NO3-, 减少N2O的转化和排放[33].

2.5 温室气体综合增温效应

为了更加准确地反映堆体温室气体综合增温效应, 采用IPCC 2014年第5次会议报告的温室气体增温潜势表示方法(CO2不计入其内)进行温室效应核算, CK、S1、S2和S3处理CO2排放当量(以干污泥计)分别为44.10、37.57、35.10和35.44 kg·t-1(表 2).陶金沙等[21]的研究表明添加生物质炭的量越大, 猪粪堆肥过程中温室气体的排放量越小.本试验中, S1、S2和S3处理CO2排放当量分别比CK减少了14.81%、20.41%和19.64%, 添加竹炭有利于堆肥过程中的温室气体减排, 其中, 以S2处理的碳减排结果最好.

表 2 污泥堆肥温室气体排放估算Table 2 Emissions of greenhouse gases during municipal sludge composting

3 结论

堆体CH4排放主要集中在升温期和高温前期, 当竹炭添加量低于5%时, CH4排放量随添加量的增加而减少; 高于5%时, CH4排放量又明显增加. CO2主要在升温期和高温期排放, 添加竹炭可减少3.37%~13.48%的CO2排放. N2O集中在升温期和降温腐熟期排放, 添加竹炭能显著降低N2O排放, 竹炭添加量越多, 减排效果越好. CK、S1、S2和S3处理CO2排放因子(以干污泥计)分别为44.10、37.57、35.10和35.44 kg·t-1, 添加竹炭可减排温室气体14.81%~20.41%.

参考文献
[1] 陈秋喜. 2016年污泥处置行业分析报告[EB/OL]. https://wenku.baidu.com/view/4dca83975acfa1c7ab00cc68.html, 2016-07-16.
[2] 刘佳, 李婉, 许修宏, 等. 接种纤维素降解菌对牛粪堆肥微生物群落的影响[J]. 环境科学, 2011, 32(10): 3073-3081.
Liu J, Li W, Xu X H, et al. Effect of cellulose-decomposing strain on microbial community of cow manure compost[J].Environmental Science, 2011, 32(10): 3073-3081.
[3] Luo Y M, Li G X, Luo W H, et al. Effect of phosphogypsum and dicyandiamide as additives on NH3, N2O and CH4 emissions during composting[J]. Journal of Environmental Sciences, 2013, 25(7): 1338-1345. DOI:10.1016/S1001-0742(12)60126-0
[4] Wang J Z, Hu Z Y, Xu X K, et al. Emissions of ammonia and greenhouse gases during combined pre-composting and vermicomposting of duck manure[J]. Waste Management, 2014, 34(8): 1546-1552. DOI:10.1016/j.wasman.2014.04.010
[5] Yang F, Li G X, Yang Q Y, et al. Effect of bulking agents on maturity and gaseous emissions during kitchen waste composting[J]. Chemosphere, 2013, 93(7): 1393-1399. DOI:10.1016/j.chemosphere.2013.07.002
[6] Lehmann J. A handful of carbon[J]. Nature, 2007, 447(7141): 143-144. DOI:10.1038/447143a
[7] 陈是吏, 袁京, 李国学, 等. 过磷酸钙和双氰胺联用减少污泥堆肥温室气体及NH3排放[J]. 农业工程学报, 2017, 33(6): 199-206.
Chen S L, Yuan J, Li G X, et al. Combination of superphosphate and dicyandiamide decreasing greenhouse gas and NH3emissions during sludge composting[J]. Transactions of the Chinese Society of Agricultural Engineering, 2017, 33(6): 199-206.
[8] Chowdhury M A, de Neergaard A, Jensen L S. Composting of solids separated from anaerobically digested animal manure: effect of different bulking agents and mixing ratios on emissions of greenhouse gases and ammonia[J]. Biosystems Engineering, 2014,124: 63-77. DOI:10.1016/j.biosystemseng.2014.06.003
[9] 易建婷, 杨雨浛, 张成, 等. 冬季污泥堆肥过程温室气体排放特征[J]. 环境科学, 2016, 37(7): 2738-2744.
Yi J T, Yang Y H, Zhang C, et al. Emissions characteristics of greenhouse gas from sewage sludge composting process in winter[J]. Environmental Science, 2016, 37(7): 2738-2744.
[10] Chen Y X, Huang X D, Han Z Y, et al. Effects of bamboo charcoal and bamboo vinegar on nitrogen conservation and heavy metals immobility during pig manure composting[J]. Chemosphere, 2010, 78(9): 1177-1181.DOI:10.1016/j.chemosphere.2009.12.029
[11] 李丽劼. 竹炭的添加对猪粪堆肥过程氮素持留与温室气体减排的影响[D]. 杭州: 浙江大学, 2012. 43-52. 
Li L J. Effects of bamboo charcoal on nitrogen conservation and greenhouse gas emissions reduction during swine manure composting[D]. Hangzhou: Zhejiang University, 2012. 43-52. http://d.wanfangdata.com.cn/Thesis/Y2270108
[12] 孙文彬. 生物质炭对城市污泥好氧堆肥过程中碳素转化及堆肥品质的影响[D]. 重庆: 重庆西南大学, 2013. 18-21. 
Sun W B. Effects of biochar on transformation of organic matter during sewage sludge composting and quality of compost[D]. Chongqing: Southwest University, 2013. 18-21. http://cdmd.cnki.com.cn/Article/CDMD-10635-1013270417.htm
[13] 刘微, 霍荣, 张津, 等. 生物质炭对番茄秸秆和鸡粪好氧堆肥氮磷钾元素变化的影响及其机理[J]. 水土保持学报, 2015, 29(3): 289-294.
Liu W, Huo R, Zhang J, et al. Effects of biochar on N, P and K transformation of tomato straw and chicken manure composting and mechanisms[J]. Journal of Soil and Water Conservation, 2015, 29(3): 289-294.
[14] EI Kader N A, Robin P, Paillat J M, et al. Turning, compacting and the addition of water as factors affecting gaseous emissions in farm manure composting[J]. Bioresource Technology, 2007, 98(14): 2619-2628. DOI:10.1016/j.biortech.2006.07.035
[15] 魏自民, 李英军, 席北斗, 等. 三阶段温度控制接种法对堆肥有机物质变化影响[J]. 环境科学, 2008, 29(2): 540-544.
Wei Z M, Li Y J, Xi B D, et al. Effect of using three stages inoculation controlled by temperature on organic matter transformation during composting process[J]. Environmental Science, 2008, 29(2): 540-544.
[16] 魏源送, 李承强, 樊耀波, 等. 不同通风方式对污泥堆肥的影响[J]. 环境科学, 2001, 22(3): 54-59.
Wei Y S, Li C Q, Fan Y B, et al. Effect on sewage sludge composting with different aeration modes[J]. Environmental Science, 2001, 22(3): 54-59.
[17] Mahimairaja S, Bolan N S, Hedley M J, et al. Losses and transformation of nitrogen during composting of poultry manure with different amendments: an incubation experiment[J]. Bioresource Technology, 1994, 47(3): 265-273. DOI:10.1016/0960-8524(94)90190-2
[18] 贺琪, 李国学, 张亚宁, 等. 高温堆肥过程中的氮素损失及其变化规律[J]. 农业环境科学学报, 2005, 24(1): 169-173.
He Q, Li G X, Zhang Y N, et al. N loss and its characteristics during high temperature composting[J]. Journal of Agro-Environment Science, 2005, 24(1): 169-173.
[19] Fukumoto Y, Osada T, Hanajima D, et al. Patterns and quantities of NH3, NO2 and CH4 emissions during swine manure composting without forced aeration-effect of compost pile scale[J]. Bioresource technology, 2003, 89(2): 109-114.DOI:10.1016/S0960-8524(03)00060-9
[20] Hao X Y, Chang C, Larney F J, et al. Greenhouse gas emissions during cattle feedlot manure composting[J]. Journal of Environmental Quality, 2001, 30(2): 376-386. DOI:10.2134/jeq2001.302376x
[21] 陶金沙, 李正东, 刘福理, 等. 添加小麦秸秆生物质炭对猪粪堆肥腐熟程度及温室气体排放的影响[J]. 土壤通报, 2014, 45(5): 1233-1240.
Tao J S, Li Z D, Liu F L, et al. Effects of wheat straw biochar on maturity extent and greenhouse gases emissions during swine manure composting[J]. Chinese Journal of Soil Science, 2014, 45(5): 1233-1240.
[22] Szanto G L, Hamelers H V M, Rulkens W H, et al. NH3, N2O and CH4 emissions during passively aerated composting of straw-rich pig manure[J]. Bioresource Technology, 2007, 98(14): 2659-2670. DOI:10.1016/j.biortech.2006.09.021
[23] Pietikäinen J, Kiikkilä O, Fritze H. Charcoal as a habitat for microbes and its effect on the microbial community of the underlying humus[J]. Oikos, 2000, 89(2): 231-242. DOI:10.1034/j.1600-0706.2000.890203.x
[24] Steiner C, Teixeira W G, Lehmann J, et al. Microbial response to charcoal amendments of highly weathered soils and Amazonian dark earths in central Amazonia-preliminary results[A]. In: Glaser B, Woods W I (Eds.). Amazonian Dark Earth: Explorations in Space and Time[M]. Berlin Heidelberg: Springer, 2004: 195-212.
[25] 黄向东. 竹炭与竹醋液对猪粪堆肥过程污染物控制效果及堆肥资源化利用研究[D]. 杭州: 浙江大学, 2010. 51-58. 
Huang X D. Effects of bamboo charcoal and bamboo vinegar on pollutant control during pig manure composting and resource utilization of compost[D]. Hangzhou: Zhejiang University, 2010. 51-58. http://cdmd.cnki.com.cn/Article/CDMD-10335-2010166362.htm
[26] Peng X, Ye L L, Wang C H, et al. Temperature-and duration-dependent rice straw-derived biochar: characteristics and its effects on soil properties of an ultisol in southern China[J]. Soil and Tillage Research, 2011, 112(2): 159-166.DOI:10.1016/j.still.2011.01.002
[27] 严慧霞. 生物质炭对堆肥及稻作的农学与环境效应研究[D]. 扬州: 扬州大学, 2014. 20-29. 
Yan H X. The agriculture and environment effects of biochar on composting and paddy cultivation[D]. Yangzhou: Yangzhou University, 2014. 20-29. http://cdmd.cnki.com.cn/article/cdmd-11117-1014359440.htm
[28] Mukherjee A, Lal R. Biochar impacts on soil physical properties and greenhouse gas emissions[J]. Agronomy, 2013, 3(2): 313-339. DOI:10.3390/agronomy3020313
[29] Cathcart T P, Wheaton F W, Brinsfield R B. Optimizing variables affecting composting of blue-crab scrap[J]. Agricultural Wastes, 1986, 15(4): 269-287. DOI:10.1016/0141-4607(86)90024-7
[30] Zimmerman A R. Abiotic and microbial oxidation of laboratory-produced black carbon (biochar)[J]. Environmental Science & Technology, 2010, 44(4): 1295-1301.
[31] 赵晨阳, 李洪枚, 魏源送, 等. 翻堆频率对猪粪条垛堆肥过程温室气体和氨气排放的影响[J]. 环境科学, 2014, 35(2): 533-540.
Zhao C Y, Li H M, Wei Y S, et al. Effects of turning frequency on emission of greenhouse gas and ammonia during swine manure windrow composting[J]. Environmental Science, 2014, 35(2): 533-540.
[32] Wang C, Lu H H, Dong D, et al. Insight into the effects of biochar on manure composting: evidence supporting the relationship between N2O emission and denitrifying community[J]. Environmental Science & Technology, 2013, 47(13): 7341-7349.
[33] Peigné J, Girardin P. Environmental impacts of farm-scale composting practices[J]. Water, Air, and Soil Pollution, 2004, 153(1-4): 45-68. DOI:10.1023/B:WATE.0000019932.04020.b6