Combined pre-degradation and anaerobic digestion for the treatment of a baker's yeast factory effluent

1997 ◽  
Vol 36 (6-7) ◽  
pp. 295-301 ◽  
Author(s):  
M. Van Der Merwe-Botha ◽  
T. J. Britz

A Chryseomonas luteola strain was isolated from raw baker's yeast factory effluent as the dominant part of the microbial community and evaluated for its biodegradative activity, using the raw effluent as substrate. The strain was able to utilise the raw effluent and produce higher concentrations of energetically favourable metabolites and thereby, could contribute to the first degradation step in an anaerobic biological treatment process. A 3×4×3 factorial design indicated optimal degradation conditions in a specific environmental framework of 48 h incubation time, COD concentration of 30 g/l, pH of 6.0 and temperature of 35°C. The C. luteola strain was thereafter used in a pre-degradation step followed by an anaerobic digestion step in a 5 1 laboratory-scale hybrid digester. With the use of the pre-degraded effluent, significant improvements were found in the overall anaerobic digestion performance. These included increased COD (>15%) and TVFA (>50%) removals, especially propionic acid (88%) removal, as well as higher biogas yields (18%). The results also showed a prominent improvement in fatty acid utilisation and methanogenesis. The pre-degradation step resulted in better process control and increased stability of the system, even at relatively high organic loading rates (10 kg COD/m3.d). When the raw effluent was not pre-treated (control bioreactor), no improvement in bioreactor efficiency was observed.

2014 ◽  
Vol 953-954 ◽  
pp. 300-303 ◽  
Author(s):  
Fang Yin ◽  
Wu Di Zhang ◽  
Jing Liu ◽  
Hong Yang

The essence of the two phase anaerobic biological treatment process is to place acid bacteria and methane-producing bacteria in two reactors respectively, where it can provide the optimal conditions for their growth and metabolism, allowing them to live up to their maximal activity, which greatly improve processing capacity and efficiency compared to a single-phase anaerobic digestion. The paper start with the two phase anaerobic digestion process, in order to discuss the development direction of high efficient anaerobic digestion system.


2005 ◽  
Vol 52 (10-11) ◽  
pp. 273-280 ◽  
Author(s):  
S. Kalyuzhnyi ◽  
M. Gladchenko ◽  
E. Starostina ◽  
S. Shcherbakov ◽  
B. Versprille

The UASB reactor (35°C) was quite efficient for removal of bulk COD (52–74%) from simulated (on the basis of cultivation medium from the first separation process) general effluent of baker's yeast production (the average organic loading rates varied from 8.1 to 16g COD/l/d). The aerobic-anoxic biofilter (19–23°C) can be used for removal of remaining BOD and ammonia from anaerobic effluents; however, it suffered from COD-deficiency to fulfil denitrification requirements. To balance COD/N ratio, some bypass (∼10%) of anaerobically untreated general effluent should be added to the biofilter feed. The application of iron (III)-, aluminium- or calcium-induced coagulation for post-treatment of aerobic-anoxic effluents can fulfil the limits for discharge to sewerage (even for colour mainly exerted by hardly biodegradable melanoidins), however, the required amounts of coagulants were relatively high.


2014 ◽  
Vol 13 (12) ◽  
pp. 3153-3160 ◽  
Author(s):  
Zakaria Al-Qodah ◽  
Mohammad Al-Shannag ◽  
Kholoud Alananbeh ◽  
Nahla Bouqellah ◽  
Eman Assirey ◽  
...  

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©


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