Center for Pollution Control and Environmental Engineering, Pondicherry University, Puducherry 605014, India.
J Adv Res. 2015 Jan;6(1):73-8. doi: 10.1016/j.jare.2014.05.006. Epub 2014 May 28.
Volatile fatty acids (VFAs), comprising mainly of acetic acid and lesser quantities of propionic and butyric acids, are generated when zoomass or phytomass is acted upon by acidogenic and acetogenic microorganisms. VFAs can be utilized by methanogens under anaerobic conditions to generate flammable methane-carbon dioxide mixtures known as 'biogas'. Acting on the premise that this manner of VFA utilization for generating relatively clean energy can be easily accomplished in a controlled fashion in conventional biogas plants as well as higher-rate anaerobic digesters, we have carried out studies aimed to generate VFAs from the pernicious weed ipomoea (Ipomoea carnea). The VFA extraction was accomplished by a simple yet effective technology, appropriate for use even by laypersons. For this acid-phase reactors were set, to which measured quantities of ipomoea leaves were charged along with water inoculated with cow dung. The reactors were stirred intermittently. It was found that VFA production started within hours of the mixing of the reactants and peaked by the 10(th) or 11(th) day in all the reactors, effecting a conversion of over 10% of the biomass into VFAs. The reactor performance had good reproducibility and the process appeared easily controllable, frugal and robust.
挥发性脂肪酸（VFAs）主要由乙酸和少量丙酸和丁酸组成，当 Zoomass 或 Phytomass 受到产酸菌和产乙酸菌微生物的作用时就会产生。在厌氧条件下，VFAs 可被产甲烷菌利用生成易燃的甲烷-二氧化碳混合物，称为“沼气”。基于这种利用 VFA 生成相对清洁能源的方式可以在传统沼气厂以及高速率厌氧消化器中以可控的方式轻松完成的前提，我们开展了从恶性杂草Ipomoea（Ipomoea carnea）中生成 VFA 的研究。通过一种简单而有效的技术实现了 VFA 提取，即使是外行人也可以使用。为此，我们设置了酸相反应器，向其中加入定量的Ipomoea 叶片和接种了牛粪的水。反应器间歇性搅拌。结果发现，反应物混合后的几个小时内就开始产生 VFA，所有反应器在第 10 天或第 11 天达到峰值，将超过 10%的生物质转化为 VFA。反应器性能具有良好的重现性，而且该过程似乎易于控制、节俭和稳健。
