The Use of NaOH Solutions for Fouling Control in a Membrane Bioreactor: A Feasibility Study

Abstract

Nowadays, the microbial production of 1,3-propanediol (1,3-PD) is recognized as preferable to the chemical synthesis. However, finding a technological approach allowing the production of 1,3-PD in the membrane bioreactor (MBR) is a great challenge. In the present study, a ceramic ultrafiltration (UF) membrane (8 kDa) for treatment of 1,3-PD broths was used. It has been demonstrated that the membrane used provides the stable permeate flux that is necessary to ensure the stability of the fermentation process in MBR technology. It was noticed that the broth pH has a significant impact on both the final 1,3-PD concentration and permeate flux. Moreover, the feasibility of using NaOH for fouling control in the MBR was evaluated. It has been shown that 1% NaOH solution is effective in restoring the initial membrane performance. To the best of our knowledge, this study is the first to shed light onto the possibility of reducing the amount of the alkaline solutions generated during the MBR operation. Indeed, it has been found that 1% NaOH solution can be successfully used several times for both membrane cleaning and to stabilize the broth pH. Finally, based on the results obtained, the technological conceptions of the MBR technology were designed.

The Resistance of Polyethersulfone Membranes on the Alkaline Cleaning Solutions

“…Fouling is one of the main reasons that make the application of membrane processes difficult. Acid and alkali solutions are often used to remove deposits from membrane surfaces [6,8,15]. Effective cleaning using alkali (e.g., NaOH) of fouled PES membranes has been demonstrated in many studies [11,12,16].…”

A Review on Applications of Artificial Intelligence in Wastewater Treatment

“…Overall, membrane fouling is the key impact factor limiting the performance and cost of membrane processes, and researchers have been trying to develop efficient and sustainable fouling control strategies. Tomczak, Grubecki and Gryta [74] proposed a method for membrane fouling control in an MBR using 1% NaOH solutions and demonstrated that the method is effective in restoring the initial membrane performance. In the membrane processes or MBR-related application studies, how to control membrane fouling and optimize MBR performance effectively and economically are two of the most central questions for the rapid commercialization of and large-scale applications in WWT [75][76][77].…”

Fouling of the Nanofiltration Membrane NF270 Used for Separation of Fermentation Broths: Impact of Feed Pretreatment Process

“…The investigations have been focused on the separation of 1,3-PD fermentation broths obtained via glycerol fermentation with the use of Citrobacter freundii bacteria. The detailed information on the fermentation process conditions have been presented in several previous articles [39,45,48,49]. After the fermentation, the broths contained bacteria; 1,3-PD; glycerol; mono-carboxylic acids (lactic, acetic and formic acid) and dicarboxylic acid (succinic acid); and ethanol, as well as residual bacterial growth medium.…”