Sustainable solutions for organic waste management: nitrogen emission reduction in parallel with greenhouse gases

氨挥发是一种主要的大气污染物，导致氮以一定速度沉积在影响水生生态系统、土壤二氧化碳排放和敏感作物的地点。超过70%的氨排放来自有机废物管理，特别是牲畜粪便。未来，更多的食物垃圾堆肥将增加氨挥发。厌氧消化是一种解决方案，但需要生产商承诺提供清洁的食物垃圾来源。沿着过去开发的可持续管理有机废物和废水的技术，本研究的目的是引入衰减氨挥发的系统。更具体地说，拟议的研究将进一步开发一个可行的系统，即存储厌氧消化系统（ISPAD），减少储存超过100天的废水（如牲畜粪便）的温室气体，气味和氨排放。这项研究将为国际土壤和农业发展研究所保留的粪肥开发一种酸化方法，以便一旦移走用于土地喷洒，氨的挥发就受到限制。该研究将：确定猪粪中铵和氨之间的平衡常数，作为温度和pH值的函数，因为这个常数不同于水;然后，测量猪粪缓冲能力（抗酸化性）及其变化取决于所使用的动物饲料;然后，找出各种粪肥处理，包括降低铵含量，最后，测试ISPAD充分酸化处理过的粪肥所需的条件。与此同时，可以开发铵回收系统来生产肥料。除了ISPAD之外，还建议着手开发一个系统，以最小的生产者努力对食物垃圾进行清洁来源的分离。此外，还将实施减少堆肥氨挥发的战略。这项研究的意义在于将加拿大的氨排放量减少50%，并将这项技术推广到世界各地，例如欧洲，那里的氮沉积也是一个主要问题。如果转化为肥料，这种氮的保存可以减少北美和欧洲天然气使用量的6-7%。

Ammonia volatilization is a major atmospheric pollutant resulting in the deposition of nitrogen at rates in locations affecting aquatic ecosystems, soil carbon dioxide emissions and sensitive crops. Over 70% of ammonia emissions originate from organic waste management, especially livestock manures. In the future, more food waste composting will increase ammonia volatilization. Anaerobic digestion is a solution but producer commitment is required for a clean source of food waste. Along with past technologies developed to sustainably manage organic wastes and wastewaters, the aim of the present research is to introduce systems attenuating ammonia volatilization. More specifically, the proposed research will further develop a feasible system, In-Storage-Anaerobic-Digestion (ISPAD), reducing greenhouse gas, odour and ammonia emissions from wastewaters stored over 100 days such as livestock manures. The research will develop an acidifying method for the manures retained in ISPAD such that, once removed for land spreading, ammonia volatilization is limited. The research will: establish the equilibrium constant between ammonium and ammonia in swine manures, as a function of temperature and pH, because this constant differs from that of water; then, measure swine manure buffer capacity (resistance to acidification) and its variability depending on the animal feed used; then, find how much buffering capacity is removed with various manure treatments, including lowering ammonium levels; finally, test ISPAD conditions required to adequately acidify the treated manure. In parallel, an ammonium recovery system can be developed to produce fertilizers. In addition to ISPAD, it is proposed to initiate the development of a system for the clean source separation of food waste with minimum producer effort. Also, strategies to reduce ammonia volatilization from compost will be pursued. The significance of the proposed research is to reduce ammonia emissions in Canada by 50%, and to extend this technology to the world, such as Europe where N deposition is also a major concern. If transformed into fertilizers, this nitrogen conservation can drop by 6-7% of the use of natural gas in North America and Europe.