scholarly journals Сyanoprokaryota cultivation with the lighting unit under different light regimes

Author(s):  
D. I. Petrukhina

The continuous phototrophic growth and light / dark cycled regime showed comparable OTR, max. µ 0.06 h-1, biomass concentration ca. 0.8 g‧L-1. During growth with 1.5 g‧L-1 glucose compared to the phototrophic showed the higher OTR.


2000 ◽  
Vol 41 (4-5) ◽  
pp. 393-400 ◽  
Author(s):  
J.M. Garrido-Fernandez ◽  
R. Méndez ◽  
J.M. Lema ◽  
V. Lazarova

Three Circulating Floating Bed Reactors (CFBR) R1, R2 and R3 with 20% v/v of a plastic carrier with different size distribution were operated to study the effect of the particles size of the carrier on biomass accumulation and nitrification performance. Operating conditions were similar in the three systems: ammonia concentrations around 50 mg-N–NH4+/ L, ammonia loading rates up to 1.2 kg N–NH4+/m3·d and temperatures between 14 and 27°C. Accumulation of nitrite was observed until day 65th. This w as result both of the inhibition of nitrite oxidation by free ammonia until day 20th and the insignificant accumulation of a biomass with low nitrite oxidising capacity between days 20 and 65th. Ammonia conversion rate and removal efficiency were higher in the reactor with lower particle size, R3 (nitrification rate of 1.1 kg N–NH4+/m3·d and ammonia removal of 97% at 16°C), than in R2 or R1 (nitrification rate of 1.0 kg N–NH4+/m3·d and ammonia removal of 90% at 16°C). The better efficiency in R3 was obtained as a result of the higher specific surface of the biofilm developed. Biomass activity was similar in the three reactors (2.2 and 1.12 g N/g protein · d at 30 and 15°C, respectively). Both the biomass evolution with time and biomass retention in the systems was practically not influenced by the size of particle. Biomass concentration of 1.2 g protein/L was retained in the carrier and up to 20% of the newly produced biomass was retained in the CFBRs.



1986 ◽  
Vol 18 (7-8) ◽  
pp. 239-248 ◽  
Author(s):  
Sung Ryong Ha ◽  
Dwang Ho Lee ◽  
Sang Eun Lee

Laboratory scale experiments were conducted to develop a mathematical model for the anaerobic digestion of a mixture of night soil and septic tank sludge. The optimum mixing ratio by volume between night soil and septic tank sludge was found to be 7:3. Due to the high solids content in the influent waste, mixed-liquor volatile suspended solids (MLVSS) was not considered to be a proper parameter for biomass concentration, therefore, the active biomass concentration was estimated based on deoxyribonucleic acid (DNA) concentration in the reactor. The weight ratio between acidogenic bacteria and methanogenic bacteria in the mixed culture of a well-operated anaerobic digester was approximately 3:2. The proposed model indicates that the amount of volatile acid produced and the gas production rate can be expressed as a function of hydraulic residence time (HRT). The kinetic constants of the two phases of the anaerobic digestion process were determined, and a computer was used to simulate results using the proposed model for the various operating parameters, such as BOD5 and volatile acid concentrations in effluent, biomass concentrations and gas production rates. These were consistent with the experimental data.



2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Nur Syamimi Zaidi ◽  
Johan Sohaili ◽  
Khalida Muda ◽  
Mika Sillanpää ◽  
Norelyza Hussein

AbstractLow condition of dissolved oxygen (DO) is commonly associated with sludge bulking problem that was able to disrupt the efficiency of wastewater treatment performances. Relatively, very little attention was paid to the possibility of applying magnetic field in controlling the bulking problem. Hence, this study aims to investigate the performance of magnetic field on biomass properties and its effect on biodegradation under low condition of DO. Two continuous laboratory-scale sequencing batch reactors—Reactor A (SBRA) and Reactor B (SBRB)—were setup. SBRA was equipped with the magnetic device to exhibit magnetic field of 88 mT, while SBRB acted as a control system. The results showed that the biomass concentration in SBRA was higher compared to SBRB. High biomass concentration in SBRA resulted to better settleability with mean SVI of less than 30 mL/g. SBRA also showed consistently high removal performances of organic and inorganic contents compared to SBRB. These observations confirmed that the magnetic field was able to enhance the biomass properties, which further enhance the biodegradation ability of the aerobic bacteria under low DO condition. This also indicates that under the sludge bulking circumstances, the use of magnetic field stands a great chance in maintaining high biodegradation of the treatment system.



2021 ◽  
Vol 640 (7) ◽  
pp. 072013
Author(s):  
I A Avtsinov ◽  
A N Gavrilov ◽  
N V Sukhanova ◽  
Yu E Kozhevnikov ◽  
S A Nickel ◽  
...  


1974 ◽  
Vol 54 (1) ◽  
pp. 129-133
Author(s):  
T. MATSUMOTO ◽  
C. A. HORNBY

The hypothesis that blotchy ripening (BR) of greenhouse tomatoes (Lycopersicon esculentum Mill.) was associated with a cumulative effect of alternating periods of bright sunshine and cloudy weather was tested in controlled environment chambers. Temperatures were programed to give diurnal changes between 11.7 C/26.7 C night/day representing sunny days, and 11.7 C/21.2 C night/day for cloudy days. The two levels of light were (1) 18,299 lx for sunny days, and (2) 16,656 lx for cloudy days. These two factors were combined in four regimes to represent (1) sunny-day temperature and light; (2) sunny-day temperature and alternate weeks of sunny-day and cloudy-day light; (3) alternate weeks of sunny-day and cloudy-day temperature and sunny-day light; and (4) alternate weeks of sunny-day temperature and light, and cloudy-day temperature and light. Four series of plants showed a common trend. Consistent sunny-day temperature and alternating weeks of sunny or cloudy-day light produced the highest incidence of BR. Alternating weeks of temperature levels with consistent sunny-day light produced less BR but not significantly so. When sunny-day temperature and light were alternated weekly with cloudy day conditions, there was a reduced percentage of BR and less severe symptoms. This regime suggests a compensatory effect when temperature is varied directly with changes in light intensity. The regime for consistent sunny-day temperature and light gave the lowest BR incidence with mild symptoms.



2017 ◽  
Vol 19 (9) ◽  
pp. 3567-3578 ◽  
Author(s):  
Jianming Yang ◽  
Liang Yin ◽  
Faith H. Lessner ◽  
Ernesto S. Nakayasu ◽  
Samuel H. Payne ◽  
...  
Keyword(s):  




Author(s):  
Władysława Wojciechowska ◽  
Tomasz Lenard

AbstractThe research was carried out in a mesotrophic and dimictic lake during winters with ice cover. In the last forty years, the development of phytoplankton was analyzed in five extreme winter seasons. The studies of phytoplankton characteristics in the water column took into account values of biomass, concentration of chlorophyll-a and species composition, including dominant species. Differences in the vertical distribution of flagellate and non-flagellate species belonging to cyanobacteria and algae were analyzed in the gradient of light and thermal conditions. The phytoplankton biomass was low and vertically differentiated, with the lowest values at the deeper part of the water column. Flagellate species from the group of Cryptophyceae, Chrysophyceae and Dinophyceae were most abundant. Species biodiversity was low but every winter the dominant species represented different taxonomic groups. In some periods, larger non-motile phytoplankton species from green or blue-green algae dominated. The research proved that the development of phytoplankton under the ice cover was limited mainly by light and, to a lesser extent, by temperature.



2011 ◽  
Vol 219 (6) ◽  
pp. 766-775 ◽  
Author(s):  
Christina Wahl ◽  
Tong Li ◽  
Yuko Takagi ◽  
Howard Howland
Keyword(s):  


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