Experimental Studies for Improved Nitrification in Shallow Lagoon Systems

1994 ◽  
Vol 29 (4) ◽  
pp. 305-308
Author(s):  
P. H. Scott ◽  
P. M. Gross ◽  
K. Baskaran ◽  
M. A. Connor
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Experimental Studies ◽  
Organic Loading ◽  
Adverse Conditions ◽  
Loading Rates ◽  
Shallow Lagoon ◽  
Low Levels ◽  
Lagoon Systems ◽  
Experimental Ponds

Two separate experimental studies aimed at enhancing nitrification in lagoon systems are described. In the first study a system of four 1:10 scale experimental ponds was used to evaluate the potential for enhancement of nitrification through the control of hydraulic loading rates to lagoon systems. A relationship incorporating the parameters: hydraulic retention time, nitrifier growth rate, temperature, pH and chlorophyll a concentration was established. This relationship provides a useful guide to managing lagoons but further work is required to provide a better understanding of the processes involved. In the second study eight laboratory-scale reactors were used to evaluate the potential for enhancement of nitrification through the use of algal/bacterial biofilms. The study showed that these biofilms have the potential to enhance nitrification, particularly under more adverse conditions such as low hydraulic retention time, high organic loading and low levels of D.O., pH and temperature.

scholarly journals Improved hydrogen production from pharmaceutical intermediate wastewater in an anaerobic maifanite-immobilized sludge reactor

RSC Advances ◽  
2021 ◽  
Vol 11 (53) ◽  
pp. 33714-33722
Author(s):  
Ruina Liu ◽  
Youwei Lin ◽  
Xiaodong Ye ◽  
Jinzhao Hu ◽  
Gongdi Xu ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Organic Loading ◽  
Loading Rates

An anaerobic maifanite-immobilized sludge reactor was used to investigate continuous hydrogen production for treatment of pharmaceutical intermediate wastewater at different organic loading rates according to changes in the hydraulic retention time.

scholarly journals Possibilities of Obtaining Biogas from Manure and Amaranth

2021 ◽  
Vol 31 (3) ◽  
pp. 336-348
Author(s):  
Julia V. Karaeva ◽  
Svetlana S. Timofeeva
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Experimental Studies ◽  
Amaranthus Retroflexus ◽  
Dairy Manure ◽  
Organic Load ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Kinetics Of

Introduction. The use of biomass allows increasing the rate of biogas formation and its specific yield. This work aims to study the kinetics of methanogenesis and determine the optimal duration of digestion and organic load, which are the main indicators of the technological process of biogas formation. Materials and Methods. The substrate (dairy manure, biomass of amaranth) was the study object. Experimental studies were carried out using a laboratory biogas plant. The computer program (certificate No. 2018662045) was used to obtain modified Gompertz models describing the kinetics of biogas formation. Based on the obtained data, the hydraulic retention time and organic loading rate (the key parameters in the design of biogas plants were determined). Results. The paper presents the experimental studies results of the biogas formation kinetics when using dry amaranth biomass. The Gompertz mathematical models were obtained. Methane-tank control parameters (hydraulic retention time and organic loading rate) were obtained for anaerobic digestion of a new substrate. Discussion and Conclusion. The use of new co-substrate Amaranthus retroflexus L. allowed increasing the specific biogas yield from dairy manure by 52.2 % and the ultrasonic pre-treatment in combination with the herbal supplement by 89.1 %. The optimal hydraulic retention time value was 10 days and organic loading rate was 4.1 kg of volatile solids per m3 of digester per day.

Working Parameters Optimization of Hydrolysis-acidogenesis reactor in two stage anaerobic digestion of slaughterhouse Wastewater for Biogas Production

2020 ◽  
Author(s):  
Dejene Tsegaye Bedane ◽  
Mohammed Mazharuddin Khan ◽  
Seyoum Leta Asfaw
Keyword(s):  
Anaerobic Digestion ◽  
Working Conditions ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Slaughterhouse Wastewater ◽  
Working Parameters

Abstract Background : Wastewater from agro-industries such as slaughterhouse is typical organic wastewater with high value of biochemical oxygen demand, chemical oxygen demand, biological organic nutrients (Nitrogen and phosphate) which are insoluble, slowly biodegradable solids, pathogenic and non-pathogenic bacteria and viruses, parasite eggs. Moreover it contains high protein and putrefies fast leading to environmental pollution problem. This indicates that slaughterhouses are among the most environmental polluting agro-industries. Anaerobic digestion is a sequence of metabolic steps involving consortiums of several microbial populations to form a complex metabolic interaction network resulting in the conversation of organic matter into methane (CH 4 ), carbon dioxide (CO 2 ) and other trace compounds. Separation of the phase permits the optimization of the organic loading rate and HRT based on the requirements of the microbial consortiums of each phase. The purpose of this study was to optimize the working conditions for the hydrolytic - acidogenic stage in two step/phase anaerobic digestion of slaughterhouse wastewater. The setup of the laboratory scale reactor was established at Center for Environmental Science, College of Natural Science with a total volume of 40 liter (36 liter working volume and 4 liter gas space). The working parameters for hydrolytic - acidogenic stage were optimized for six hydraulic retention time 1-6 days and equivalent organic loading rate of 5366.43 – 894.41 mg COD/L day to evaluate the effect of the working parameters on the performance of hydrolytic – acidogenic reactor. Result : The finding revealed that hydraulic retention time of 3 day with organic loading rate of 1,788.81 mg COD/L day was a as an optimal working conditions for the parameters under study for the hydrolytic - acidogenic stage. The degree of hydrolysis and acidification were mainly influenced by lower hydraulic retention time (higher organic loading rate) and highest values recorded were 63.92 % at hydraulic retention time of 3 day and 53.26% at hydraulic retention time of 2 day respectively. Conclusion : The finding of the present study indicated that at steady state the concentration of soluble chemical oxygen demand and total volatile fatty acids increase as hydraulic retention time decreased or organic loading rate increased from 1 day hydraulic retention time to 3 day hydraulic retention time and decreases as hydraulic retention time increase from 4 to 6 day. The lowest concentration of NH 4 + -N and highest degree of acidification was also achieved at hydraulic retention time of 3 day. Therefore, it can be concluded that hydraulic retention time of 3 day/organic loading rate of 1,788.81 mg COD/L .day was selected as an optimal working condition for the high performance and stability during the two stage anaerobic digestion of slaughterhouse wastewater for the hydrolytic-acidogenic stage under mesophilic temperature range selected (37.5℃). Keywords : Slaughterhouse Wastewater, Hydrolytic – Acidogenic, Two Phase Anaerobic Digestion, Optimal Condition, Agro-processing wastewater

The Phosphorous Removal after Anaerobic Stages of Different Durations and under Different Organic Loadings in the Reversed A2/O Process

2011 ◽  
Vol 183-185 ◽  
pp. 1195-1199
Author(s):  
Feng Zhang ◽  
Chang Qing Liu ◽  
Zhong Qiao ◽  
Gong Fa Chang ◽  
Yan Hui Qu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Retention Time ◽  
Uptake Rate ◽  
Hydraulic Retention Time ◽  
Carbon Sources ◽  
Phosphorus Uptake ◽  
Organic Loading ◽  
Phosphorous Removal ◽  
Available Carbon ◽  
Anaerobic Reaction

The phosphorous removal behaviors under higher and moderate organic loading and after different durations of anaerobic stages were studied in the reversed A2/O process. Under both loading, the length of anaerobic stages did not significantly affect the subsequent aerobic phosphorus uptake efficiencies. Under higher loading, the available carbon sources are adequate, prolonging anaerobic stages led to more released phosphorus from phosphate accumulating organisms (PAOs). However, the phosphorus uptake rate in aerobic stage was almost the same as that of lower loading. At an anaerobic reaction time of 2.0 h, the corresponding specific aerobic phosphorus uptake rate achieved the highest value (6.13 mg/(L.h)). These results can help to determine the anaerobic hydraulic retention time in the reversed A2/O process.

Impact of Hydraulic Retention Time at Constant Organic Loading Rate in a Two-Stage Expanded Granular Sludge Bed Reactor

2014 ◽  
Vol 31 (6) ◽  
pp. 317-323 ◽  
Author(s):  
Mahyar Ghorbanian ◽  
Robert M. Lupitskyy ◽  
Jagannadh V. Satyavolu ◽  
R. Eric Berson
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Granular Sludge ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Two Stage

scholarly journals Performance of Modified Anaerobic Hybrid Baffled (MAHB) bioreactor treating recycled paper mill effluent: Effects of organic loading rates

2021 ◽  
Vol 6 (1) ◽  
pp. 15-18
Author(s):  
Siti Roshayu Hassan ◽  
Irvan Dahlan
Keyword(s):  
Hydraulic Retention Time ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Paper Mill ◽  
Organic Loading ◽  
Recycled Paper ◽  
Paper Mill Effluent ◽  
Loading Rates ◽  
Bioreactor System ◽  
Maximum Removal

The performance of modified anaerobic hybrid baffled (MAHB) bioreactor treating recycled paper mill effluent (RPME) was investigated at various organic loading rates (OLR) of 1, 2, 3 and 4 g COD/ L.day. The bioreactor was operated continuously at constant hydraulic retention time (HRT) of a day without effluent recycled and chemicals adjustment/addition. Throughout 70 days of operation, a maximum removal efficiency up to 97% of chemical oxygen demand (COD) and 98% of volatile fatty acid, biogas production of 12.51 L/day equivalent to methane (CH4) yield of 0.108L CH4/ g COD and a stable pH system between 6.6 to 7.2 were achieved. Additionally, alkalinity of the bioreactor system shows a stable profile that indicates the whole system was well buffered with a quit high degradation of volatile solid (VS) up to 18%. These results indicated that MAHB bioreactor has been successfully treated RPME at various OLR.

Assessment of classical surface organic loading design equations based on the actual performance of primary and secondary facultative ponds

2010 ◽  
Vol 61 (4) ◽  
pp. 971-977 ◽  
Author(s):  
Sílvia C. Oliveira ◽  
Marcos von Sperling
Keyword(s):  
Performance Evaluation ◽  
Hydraulic Retention Time ◽  
Operating Conditions ◽  
Empirical Equations ◽  
Organic Loading ◽  
Actual Performance ◽  
Loading Rates ◽  
Limit Value ◽  
Classical Design ◽  
Operational Aspects

This article presents results from a performance evaluation of 73 full-scale primary facultative ponds and 37 secondary facultative ponds in Brazil. The data were used to test the applicability of some classical design equations for recommended surface BOD loading rates. The empirical equations proposed by Mara in 1976 and 1987 and the equation developed by McGarry and Pescod in 1970 were evaluated. The loading and hydraulic operating conditions were also evaluated to support the analysis of the influence of the parameters surface BOD loading (Ls) and hydraulic retention time (HRT) on the performance of the ponds. The results showed that the design equations proposed by Mara showed good applicability for primary facultative ponds, representing good indicators of the limit value of loading rates to be applied on the units. But the secondary facultative ponds showed good and poor performances for all loading rates and the best ponds, in general, were not those which followed the design equations recommendation. Finally, the influence of the actual loading conditions on the ponds performance was very small and scattered, indicating that other unquantified design and operational aspects were playing an important role.

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