鸡粪堆肥含氮和含硫废气产生机制及控制技术研究进展

堆肥技术是鸡粪无害化处理的重要途径,但堆肥过程中产生的废气对堆肥质量产生不利影响,对生态环境与人类健康造成危害,因此对鸡粪堆肥时产生的废气的控制技术是堆肥技术发展的限制性因素之一。这些废气通常组分复杂,气味较重,其中含有氮和硫两种元素的废气是重点研究对象,包括有氨、氮氧化物、硫化氢,以及含氮和含硫的醇类、酮类、醚类等气态挥发性有机化合物,文章介绍了这些废气中主要成分的产生机理,简述了其排放强度的规律与鸡粪性质、堆肥环境及工艺条件相关参数的关系,从优化堆肥工艺条件(温度、含氧量、pH、碳氮比和含水量),采用生物法(添加微生物菌剂、生物过滤法和生物联合堆肥)、调节剂法(添加生物炭和其他添加剂)和末端技术等方面降低或去除堆肥过程中废气的排放,回顾了国内外学者们近年在此方面的研究成果,分析了各方法对不同废气的去除效果和实际应用中的问题,探讨了其未来在生产实践中应用的前景,以期为鸡粪及其他废物堆肥过程中的废气控制研究提供参考。

Effects of Superphosphate Addition on NH_3 and Greenhouse Gas Emissions During Vegetable Waste Composting

To study the effects of superphosphate（SP） on the NH_3 and greenhouse gas emissions,vegetable waste composting was performed for 27 days using 6 different treatments. In addition to the controls,five vegetable waste mixtures（0.77m^3 each） were treated with different amounts of the SP additive, namely, 5%, 10%,15%, 20% and 25%. The ammonia volatilization loss and greenhouse gas emissions were measured during composting.Results indicated that the SP additive significantly decreased the ammonia volatilization and greenhouse gas emissions during vegetable waste composting. The additive reduced the total NH_3 emission by 4.0% to 16.7%. The total greenhouse gas emissions（CO_2-eq） of all treatments with SP additives were decreased by 10.2% to 20.8%, as compared with the controls. The NH_3 emission during vegetable waste composting had the highest contribution to the greenhouse effect caused by the four different gases.The amount of NH_3（CO_2-eq）from each treatment ranged from 59.90 to 81.58 kg/t; NH_3（CO_2-eq） accounted for 69% to 77% of the total emissions from the four gases. Therefore, SP is a cost-effective phosphorus-based fertilizer that can be used as an additive during vegetable waste composting to reduce the NH_3 and greenhouse gas emissions as well as to improve the value of compost as a fertilizer.

Adsorption Properties of Adsorption Tower Filled with Calcium Superphosphate on NH_3 Emitted from Composting System of Animal Wastes

[Objective] This study aimed to investigate the adsorption properties of the adsorption tower filled with calcium superphosphate on ammonia volatilized with aer- ation. [Method] Adsorption tower filled with calcium superphosphate was adopted as experimental apparatus, which was constructed by poly vinyl chloride （PVC） circular tubes. With hartshorn as the source of ammonia volatilization, the effect of different ratios of height to diameter of the tower filled with equal amount of calcium super-phosphate on ammonia adsorption was investigated. In addition, adsorption tower with height-diameter ratio of 9.9 was selected to adsorb the ammonia emitted from the composting systems of pig manure and chicken manure with optimized and reg- ulated carbon-nitrogen ratio. [Result] Under certain volatilization rate, calcium super- phosphate particles in the adsorption tower could effectively adsorb the ammonia, and the adsorption efficiency was enhanced with the increase of height-diameter ra-tio, which could reach above 90% with height-diameter ratio of more than 1.1; the ammonia emitted from composting systems of pig manure and chicken manure with optimized and regulated carbon-nitrogen ratio could be completely absorbed using adsorption tower with height-diameter ratio of 9.9 filled with calcium superphosphate accounting for about 8% of the weight of composting materials. [Conclusion] Experi- mental results of this study provided reference for the application of adsorption tower filled with calcium superphosphate in the treatment of waste gas emitted from com- posting materials.

Influence of bulking agents on CH_4,N_2O,and NH_3 emissions during rapid composting of pig manure from the Chinese Ganqinfen system

Mismanagement of the composting process can result in emissions of CH4,N2O,and NH3,which have caused severe environmental problems.This study was aimed at determining whether CH4,N2O,and NH3 emissions from composting are affected by bulking agents during rapid composting of pig manure from the Chinese Ganqinfen system.Three bulking agents,corn stalks,spent mushroom compost,and sawdust,were used in composting with pig manure in 60 L reactors with forced aeration for more than a month.Gas emissions were measured continuously,and detailed gas emission patterns were obtained.Concentrations of NH3 and N2O from the composting pig manure mixed with corn stalks or sawdust were higher than those from the spent mushroom compost treatment,especially the sawdust treatment,which had the highest total nitrogen loss among the three runs.Most of the nitrogen was lost in the form of NH3,which accounts for 11.16% to 35.69% of the initial nitrogen.One-way analysis of variance for NH3emission showed no significant differences between the corn stalk and sawdust treatments,but a significant difference was noted between the spent mushroom compost and sawdust treatments.The introduction of sawdust reduced CH4emission more than the corn stalks and spent mushroom compost.However,there were no significant differences among the three runs for total carbon loss.All treatments were matured after 30 d.