Phenol biodegradation by bacterial cultures encapsulated in 3D microfiltration-membrane capsules

    Eyal Kurzbaum, Yasmin Raizner, Martin E. Kuc, Anatoly Kulikov, Ben Hakimi, Lilach Iasur Kruh and Ofir Menashe, Environmental technology, 2019.

    Abstract: The aim of the study was to evaluate the performance of batch and semi-continuous treatment systems for phenol degradation using a consortium of bacterial cultures that were encapsulated using the ‘Small Bioreactor Platform’ (SBP) encapsulation method. The maximal phenol biodegradation rate was 22 and 48 mg/L/h at an initial phenol concentration of 100 and 1000 mg/L in the batch and semi-continuous bioreactors, respectively. The initial phenol concentration played an important role in the degradation efficiency rates. The batch bioreactor results could be described by the Haldane model, where the degradation rate decreased under low as well as under very high initial phenol concentrations. Concentration equalization between the two sides of the SBP capsule’s membrane occurred after 80 min. The microfiltration membrane is perforated with holes that have an average diameter of 0.2–0.7 µm. It is therefore suggested that the capsule’s membrane is more permeable compared to other polymeric matrixes used for bacterial encapsulation (such as alginate). This study shows that the encapsulation of phenol degraders within microfiltration-membrane capsules which create a confined environment has a potential for enhancing phenol removal in phenol-rich wastewaters.

    Treatment of olive mill wastewater using ozonation followed by an encapsulated acclimated biomass

    Yeara Bar Oz, Hadas Mamane, Ofir Menashe, Vered Cohen-Yaniv, Rupak Kumar, Lilach Iasur Kruh, Eyal Kurzbaum, Journal of Environmental Chemical Engineering, 2018

    Abstract: The environmental impacts caused by Olive Mill Wastewater (OMWW) are a concern for both developing and developed countries. In this study, an ozone pretreatment combined with a fixed biomass bio-treatment using the Small Bioreactor Platform (SBP) capsules technology encasing a pure culture of a phenol-degrading OMWW isolate named Delftia EROSY was implemented to reduce phenolic compounds and organic matter in OMWW.
    Up to 90% of tannic acid (TA), a synthetic phenol model, was removed after the ozonation and biological stages. Ozone pretreatment of TA expedites the biological process by decreasing the time needed for the biodegradation of phenols.
    Ozonation (ozone dose = 765 mg L−1 O3) of OMWW demonstrated 20% COD and 61% total phenol removal, with an additional 36% increase in COD removal after the biological step (48 h). Interestingly, our results also showed that spectral absorbance can be used as a tool for monitoring ozonation followed by bio-treatment of OMWW. Absorbance results clearly demonstrate that bio-treatment is necessary for degrading not only phenolic compounds, but also phenol transformation products and the high organic load of the OMWW, following the ozonation step.

    Encapsulated Pseudomonas putida for phenol biodegradation: Use of a structural membrane for construction of a well-organized confined particle

    Eyal Kurzbaum, Yasmin Raizner, Oded Cohen, Ran Y. Suckeveriene, Anatoly Kulikov, Ben Hakimi, Lilach Iasur Kruh, Yair Farber, Ofir Menashe. Water Research, 2017, Vol.121, pages 37-45.

    Abstract: Phenols are byproducts from a wide range of industry sectors which, if not treated, create exceptionally environmentally hazardous effluents. This study presents the use of a Pseudomonas putida F1 culture encapsulated within a confined environment particle as an efficient technique for phenol biodegradation. The innovative encapsulation technique method, named the "Small Bioreactor Platform" (SBP) technology, enables the use of a constructed microfiltration membrane as a physical barrier for creating a confined environment for the encapsulated culture. The phenol biodegradation rate of the encapsulated culture was compared to its suspended state in order to evaluate the effectiveness of the encapsulation technique for phenol biodegradation. Encapsulated P. putida exhibited a maximal phenol biodegradation rate at an initial phenol concentration of 100 mg/L, with a biodegradation rate (q) of 2.12 h-1. The biodegradation rate decreased significantly at lower and higher initial phenol concentrations of 50 and up to 3000 mg/L, reaching up to 0.1018 h-1. The results also indicate similar and up to double the degradation rate between the two bacterial states (encapsulated vs. freely suspended). Images of the SBP capsule's membrane morphology using high resolution scanning electron microscopy demonstrated a highly porous microfiltration membrane that enables effcient trafficking of dissolved molecules across the membrane. These results, together with the long-term activity of the SBP capsules and the verification that the culture remains pure after 60 days using 16S rRNA gene phylogenetic affiliation tests, provide evidence for a succsesful application of this new encapsulation technique for bioaugmentation of selected microbial cultures in water treatment processes.

    A Novel Bioaugmentation Treatment Approach using a Confined Microbial Environment: A Case Study in a MBR Wastewater Treatment Plant

    Ofir Menashe and Eyal Kurzbaum, Environmental Technology, (on-line publication, DOI: 10.1080/09593330.2015.1121293), Jan. 2016.

    Abstract: A novel bioaugmentation treatment approach, the Small-Bioreactor Platform (SBP) technology, was developed to increase the biological stabilization process in the treatment of wastewater in order to improve wastewater processing effectiveness. The SBP microfiltration membrane provides protection against the natural selection forces that target exogenous bacterial cultures within wastewater. As a result, the exogenous microorganisms culture adapt and proliferate, thus providing a successful bioaugmentation process in wastewater treatment. The new bioaugmentation treatment approach was studied in a full configuration Membrane Bioreactor (MBR) plant treating domestic wastewater. Our results present the potential of this innovative technology to eliminate, or reduce, the intensity of stress events, as well as shortening the recovery time after stress events, consequently elevating the treatment effectiveness. The effective dose of SBP capsules per cubic meter per day of wastewater was achieved during the addition of 3000 SBP capsules (1.25 SBP capsules per cubic meter per day), which provided approximately 4.5 liters of high concentration exogenous biomass culture within the SBP capsules internal medium. This study demonstrates an innovative treatment capability which provides an effective bioaugmentation treatment in a MBR domestic wastewater treatment plant.

    The potential of autochthonous microbial culture encapsulation in a confined environment for phenols biodegradation

    Hassan Azaizeh, Eyal Kurzbaum, Ons Said, Husain Jaradat, Ofir Menashe. Environmental Science and Pollutants Research (ESPR), 2015 Vol. 22 (19) pages: 15179-15187.

    Olive mill wastewater (OMWW) is claimed to be one of the most polluting effluents produced by agro-food industries, providing high contaminants load that encase cytotoxic agents such as phenolic and polyphenolic compounds. Therefore, a significant and continuous stress episode is induced once the mixed liquor of the wastewater treatment plants (WWTP’s) is being exposed to OMWW. The use of bio-augmentation treatment procedures can be useful to eliminate or reduce such stress episodes. In this study, we have estimated the use of autochthonous biomass implementation within small bioreactor platform (SBP) particles as a bioaugmentation method to challenge against WWTPs stress episodes. Our results showed that SBP particles significantly reduced the presence of various phenolics: tannic, gallic and caffeic acid in a synthetic medium and in crude OMWW matrix. Moreover, the SBP particles succeeded to biodegrade a very high concentration of phenol blend (3000 mg L−1). Our findings indicated that the presence of the SBP microfiltration membrane has reduced the phenol biodegradation rate by 50 % compared to the same suspended culture. Despite the observed reduction in biodegradation rate, encapsulation in a confined environment can offer significant values such as overcoming the grazing forcers and dilution, thus achieving a long-term sufficient biomass. The potential for reducing stress episodes caused by cytotoxic agents through bioaugmentation treatment procedure using the SBP technology is discussed.

    Small-bioreactor platform technology as a municipal wastewater additive treatment

    Ofir Menashe and Eyal Kurzbaum, Water Science & Technology, 2014, Vol.69 (3), pages 504-510.

    The bioaugmentation treatment approach presents both an economical and environmentally friendly solution for wastewater treatment. However, the use of exogenous bacterial cultures presents several limitations: negative interaction between microorganisms and adaptation to new physical and chemical composite environment. These selective forces create a significant challenge for the introduced culture to achieving the required biomass in order to conduct the target biological treatment. Small-bioreactor platform (SBP) technology is aimed at introducing exogenous bacterial culture with some protection to reduce some of the natural selection process. The current study was aimed at validating the use of SBP technology to improve biological treatment, especially during a stress period, by using macro-encapsulated bioaugmentation treatment. The study results indicate that the use of SBP technology elevates the stability of biological treatment, improving operational factors such as the reduction of foaming phenomena and sludge accumulation. Still, a significant study needs to be conducted to understand the potential of this technology; especially the impact on biological treatment by using different types of microorganisms for different types of wastewaters and the relationship between the biomass within the SBP capsules and the natural microorganisms.