Baker’s Yeast Industry (BYI) effluent was one of the strongest wastewaster type that contains high amount of organic matter, salinity, nitrogen and sulphate. These characteristics were unfavorable for the application of wastewater treatment. For this reason, a recovery-oriented approach was applied for the appropriate conditions to increase the Volatile Fatty Acid (VFA) production potential of BYI. In this concept, hydrolysis anaerobic Membrane Bioreactor was used to produce VFAs. The hydrolysis reactor was operated between 2.5 and 13.4 days in Hydraulic Retention Time, at a thermophilic temperature (55 °C) and at pH of 4.5–8 for 858 days. The highest biomass concentration was 26 g L⁻¹ in the reactor, and mainly acetate, propionate and butrate production was observed. The highest acetate production was seen at pH 7 with an average concentration of 25,930 mg L⁻¹. The highest total VFA production yield was 0.98 g VFA–COD g⁻¹ COD. It was concluded that carrying out hydrolysis and acidification reactions at neutral pH was better as long as methane production could be avoided. In addition, a VFA-rich stream with free suspended solids could be obtained with the 0.05 µ pore diameter submerged membrane. Population dynamics remained quite stable and rich in biomass consortia throughout the study. It was suggested that a high commercial value could be obtained, especially by recovering acetate from the hydrolysis reactor’s outlet stream.

中文翻译：

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贝克酵母行业废水中挥发性脂肪酸的生产

贝克酵母工业（BYI）废水是最强的废物类型之一，其中包含大量有机物，盐分，氮和硫酸盐。这些特性不利于废水处理的应用。因此，在适当的条件下采用了面向恢复的方法，以增加BYI的挥发性脂肪酸（VFA）的生产潜力。在此概念中，水解厌氧膜生物反应器用于生产VFA。水解反应器的水力停留时间为2.5至13.4天，在高温（55°C）和pH为4.5-8的条件下运行858天。最高生物量浓度为26 g L ^-1在反应器中，主要观察到乙酸盐，丙酸盐和丁酸盐的产生。在pH值为7时，醋酸盐产量最高，平均浓度为25,930 mg L ^-1。VFA总产量最高，为0.98 g VFA–COD g ^-1 COD。结论是，只要可以避免甲烷生成，在中性pH下进行水解和酸化反应会更好。另外，用孔径为0.05 µm的浸没膜可以得到富含VFA的游离悬浮固体流。在整个研究过程中，种群动态保持相当稳定，并拥有丰富的生物量联盟。有人认为，特别是通过从水解反应器的出口流中回收乙酸盐，可以获得很高的商业价值。