Long-term evaluation of membrane bioreactor inoculated with commercial baker's yeast treating landfill leachate: pollutant removal, microorganism dynamic and membrane fouling

2019 ◽  
Vol 79 (2) ◽  
pp. 398-410 ◽  
Author(s):  
Gabriela C. B. Brito ◽  
Liséte C. Lange ◽  
Vera L. Santos ◽  
Míriam C. S. Amaral ◽  
Wagner G. Moravia

Abstract In this study, commercial baker's yeast (Saccharomyces cerevisiae) was employed as a novel inoculum for a membrane bioreactor (MBRy). It was applied to landfill leachate (LFL) treatment to remove recalcitrant organic compounds as well as for the assimilation of recalcitrant compounds, since yeasts have a high ability to break such compounds down. The MBR was inoculated with 10 g L−1 of commercial baker's yeast and was operated at a hydraulic retention time of 48 h and pH of 3.5. The specific air demand based on the membrane area (SADm) was maintained at 0.6 m3 h−1 m−2. The MBRy achieved chemical oxygen demand (COD), color, NH3, and humic substances removal of 68, 79, 68, and 50%, respectively. Furthermore, the MBRy showed lower fouling potential, which can be attributed to the low extracellular polymeric substances production, as the formation of a cake layer was the major mechanism of membrane fouling. The work demonstrated that novel MBR is a promising technology for treating recalcitrant landfill leachate.

2014 ◽  
Vol 69 (8) ◽  
pp. 1712-1719 ◽  
Author(s):  
Fangyuan Wang ◽  
Jianrong Chen ◽  
Huachang Hong ◽  
Aijun Wang ◽  
Hongjun Lin

Real sewage was continuously treated by a laboratory-scale anaerobic submerged membrane bioreactor (AnSMBR) for over 160 days. Results showed that around 90% of chemical oxygen demand, and 99% of turbidity and total suspended solids in the sewage could be removed by the AnSMBR system. Membrane flux sustained at 11 L/(m2 h) was realized with biogas sparging. Small flocs from sludge deflocculation in the early operational period caused a high membrane fouling rate, and the high specific filtration resistance of the cake layer appeared mostly attributable to the osmotic pressure effect. The performance results were also compared with those in the literature for upflow anaerobic sludge blanket reactors and aerobic membrane bioreactors for sewage treatment, demonstrating that AnSMBR could provide a desirable alternative for sewage treatment.


Author(s):  
Qiang Liu ◽  
Ying Yao ◽  
Delan Xu

A hybrid membrane bioreactor (HMBR) employing activated sludge and biofilm simultaneously is proved to represent a good performance on membrane fouling control compared to conventional membrane bioreactor (CMBR) by reducing extracellular polymeric substances (EPS), especially bound EPS (B-EPS). In order to better understand the mechanism of membrane fouling control by the HMBR in regard of microbial community composition, a pilot scale HMBR operated to treat domestic wastewater for six months, and a CMBR operated at the same time as control group. Results showed that HMBR can effectively control membrane fouling. When transmembrane pressure reached 0.1 MPa, the membrane module in the HMBR operated for about 26.7% longer than that in the CMBR. In the HMBR, the quantity of EPS was significantly lower than that in the CMBR. In this paper, soluble EPS was also found to have a close relationship with cake layer resistance. The species richness and diversity in the HMBR were higher than those in the CMBR, and a certain difference between the compositions of microbial communities in the two reactors was confirmed. Therefore, the difference in microbial community compositions may be the direct reason why EPS in the HMBR was lower than that in the CMBR.


Author(s):  
Ida N Jamal ◽  
Reiny A Tumbol ◽  
Remy E.P Mangindaan

Motile Aeromonas Septicaemia disease (MAS) attacking tilapia has increased in recent years as a consequence of intensive aquaculture activities, which led to losses in aquaculture industry. The agent causing MAS disease is Aeromonas hydrophila. The disease can be controlled with the β-glucan. As immunostimulants, β-glucans can also increase resistance in farmed tilapia. Studies on the use of β-glucan extracted from baker's yeast Saccharomyces cerevisiae was intended to evaluate the non-specific immune system of tilapia that were challenged with Aeromonas hydrophila. The method used was an experimental method with a completely randomized design consisting of four treatments with three replicats. The dose of β-glucan used as treatments were 0 mg.kg-1 fish (Control), 5 mg.kg-1 fish (B), 10 mg.kg-1 fish (C) and 20 mg.kg-1 fish (D), each treatment as injected three times at intervals of 3 days, the injection volume of 0.5 ml/fish for nine days and resistance surveillance for seven days. The results showed that the difference in the amount of β-glucan and the frequency of the injected real influence on total leukocytes, phagocytic activity and resistance. Total leukocytes, phagocytic activity and resistance to treatment was best achieved by the administration of C a dose of  10 mg.kg-1 of the fish© Penyakit Motil Aeromonas Septicaemia (MAS) yang menyerang ikan nila mengalami peningkatan selama beberapa tahun terakhir sebagai konsekuensi dari kegiatan akuakultur intensif, yang menyebabkan kerugian dalam industri budidaya. Agen utama penyebab penyakit MAS adalah Aeromonas hydrophila. Untuk mengendalikan penyakit tersebut dapat dilakukan dengan pemberian β-glukan. Sebagai imunostimulan, β-glukan juga dapat  meningkatkan resistensi pada ikan nila yang dibudidayakan. Pengkajian mengenai pemanfaatan β-glukan yang diekstrak dari ragi roti Saccharomyces cerevisiae dimaksudkan untuk menguji sistem imun non spesifik ikan nila yang diuji tantang dengan bakteri Aeromonas hydrophila. Metode yang digunakan yaitu metode eksperimen dengan rancangan acak lengkap yang terdiri dari empat perlakuan dan tiga ulangan. Dosis β-glukan  yang digunakan sebagai perlakuan sebesar 0 mg.kg-1 ikan (Kontrol), 5 mg.kg-1 ikan (B), 10 mg.kg-1 ikan (C) dan 20 mg.kg-1 ikan (D), masing-masing perlakuan diinjeksi sebanyak 3 kali dengan interval waktu 3 hari selama 9 hari, volume injeksi 0,5 mL/ekor ikan dan pengamatan resistensi selama tujuh hari. Hasil penelitian menunjukkan perbedaan jumlah β-glukan dan frekuensi pemberian yang diinjeksikan memberikan pengaruh nyata terhadap total leukosit, aktivitas fagositosis dan resistensi. Total leukosit, aktivitas fagositosis dan resistensi terbaik dicapai pada perlakuan C dengan dosis 10 mg.kg-1 ikan©


2011 ◽  
Vol 63 (9) ◽  
pp. 1906-1912 ◽  
Author(s):  
Simos Malamis ◽  
Andreas Andreadakis ◽  
Daniel Mamais ◽  
Constantinos Noutsopoulos

The aim of this work was to evaluate the long-term performance of a Membrane Bioreactor (MBR) that operated continuously for 2.5 years and to assess membrane fouling and biomass activity under various operating conditions. Furthermore, a method for the characterisation of influent wastewater was developed based on its separation into various fractions. The MBR system operated at the solids retention times (SRT) of 10, 15, 20 and 33 days. The increase of SRT resulted in a decrease of the fouling rate associated with the reduction of extracellular polymeric substances. Moreover, the SRT increase resulted in a significant reduction of the Oxygen Uptake Rate (OUR) due to the lower availability of substrate and in a notable decrease of the maximum OUR since high SRT allowed the development of slower growing microorganisms. Biomass consisted of small flocs due to extensive deflocculation caused by intense aeration. Finally, the method developed for wastewater characterisation is straightforward and less time consuming than the usual method that is employed.


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