Operational Control of an Anaerobic GAC Reactor Treating Hazardous Wastes

1989 ◽  
Vol 21 (4-5) ◽  
pp. 167-173 ◽  
Author(s):  
G. F. Nakhla ◽  
M. T. Suidan ◽  
J. T. Pfeffer
Keyword(s):  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Partial Replacement ◽  
Second Phase ◽  
Operational Control ◽  
Anaerobic Culture ◽  
Replacement Rate ◽  
Percent Conversion ◽  
Very High

An expanded-bed GAC anaerobic reactor was employed to investigate the effect of empty bed detention time, sludge age, and chemical oxygen demand (COD) loading on process performance during the treatment of a coal conversion wastewater. The toxicity of the wastewater to the anaerobic culture was overcome by periodic partial replacement of the reactor medium with fresh GAC. The first phase of this study determined the minimum GAC replacement rate required to successfully treat the wastewater at a COD loading of 11 g-COD/kg-GAC-day. The second phase investigated the dependance of the system performance on hydraulic retention time and the volumetric COD loading rate. Very high organic removal efficiencies, as well as approximately fifty percent conversion of the influent COD to methane gas were achieved even at empty-bed hydraulic retention times as low as 7 hours.

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

Enhanced removal of chemical oxygen demand, nitrogen and phosphorus using the ameliorative anoxic/anaerobic/oxic process and micro-electrolysis

2012 ◽  
Vol 66 (4) ◽  
pp. 850-857 ◽  
Author(s):  
K. Q. Bao ◽  
J. Q. Gao ◽  
Z. B. Wang ◽  
R. Q. Zhang ◽  
Z. Y. Zhang ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Synthetic Wastewater ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Nitrogen And Phosphorus ◽  
Operational Conditions ◽  
Removal Efficiencies

Synthetic wastewater was treated using a novel system integrating the reversed anoxic/anaerobic/oxic (RAAO) process, a micro-electrolysis (ME) bed and complex biological media. The system showed superior chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) removal rates. Performance of the system was optimised by considering the influences of three major controlling factors, namely, hydraulic retention time (HRT), organic loading rate (OLR) and mixed liquor recirculation (MLR). TP removal efficiencies were 69, 87, 87 and 83% under the HRTs of 4, 8, 12 and 16 h. In contrast, HRT had negligible effects on the COD and TN removal efficiencies. COD, TN and TP removal efficiencies from synthetic wastewater were 95, 63 and 87%, respectively, at an OLR of 1.9 g/(L·d). The concentrations of COD, TN and TP in the effluent were less than 50, 15 and 1 mg/L, respectively, at the controlled MLR range of 75–100%. In this system, organics, TN and TP were primarily removed from anoxic tank regardless of the operational conditions.

Granulation of anaerobic sludge in the sulfate-reducing up-flow sludge bed (SRUSB) of SANI® process

2013 ◽  
Vol 68 (3) ◽  
pp. 560-566 ◽  
Author(s):  
T. Hao ◽  
H. Lu ◽  
H. K. Chui ◽  
Mark C. M. van Loosdrecht ◽  
G. H. Chen
Keyword(s):  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Biomass Concentration ◽  
Volume Index ◽  
Anaerobic Sludge ◽  
Sludge Volume Index ◽  
Sulfate Reducing ◽  
Full Development ◽  
Sludge Granulation

This study reports on anaerobic sludge granulation in a laboratory-scale sulfate-reducing up-flow sludge bed (SRUSB) in a novel sulfate reduction, autotrophic denitrification and nitrification integrated (SANI®) process for treatment of saline sewage. Granulation occurred in 30 d and reached full development in 90 d. The sulfate-reducing granules grew up to around 1 mm after 90 d with 21 mL/g SVI5 (sludge volume index measured after 5 min) and the biomass concentration reached 29 g/L after 4 months' operation. The reactor removed 89% chemical oxygen demand (COD) and reduced 75% sulfate within 1 h of hydraulic retention time, under a COD loading rate of up to 6.4 kg COD/(m3 · d).

Investigation of furfural biodegradation in a continuous inflow cyclic biological reactor

2015 ◽  
Vol 73 (2) ◽  
pp. 292-301 ◽  
Author(s):  
Gholamreza Moussavi ◽  
Mostafa Leili ◽  
Kazem Nadafi
Keyword(s):  
Removal Efficiency ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Filling Ratio ◽  
Operating Parameters ◽  
High Concentrations ◽  
Moving Media ◽  
Main Operating ◽  
Bioreactor Performance

The performance of a continuous inflow cyclic biological reactor (CBR) containing moving media was investigated for the degradation of high concentrations of furfural. The effects of hydraulic retention time (HRT) and furfural initial concentrations (loading rate), as main operating parameters, on the bioreactor performance were studied. The results indicated that the CBR could remove over 98% of furfural and 71% of its chemical oxygen demand (COD) at inlet furfural concentrations up to 1,200 mg L−1 (2.38 g L−1 d−1), a 6-h cycle time and HRT of 12.1 h. The removal efficiency decreased slightly from 98 to 94% when HRT decreased from 12.1 to 10.5 h. The average removal efficiency of furfural and COD during the 345-day operational period under steady-state conditions were 97.7% and 82.1%, respectively. The efficiency also increased approximately 17.2% after addition of synthetic polyurethane cubes as moving media at a filling ratio of 10%.

Anaerobic Treatment of Coal Gasification Wastewater

1987 ◽  
Vol 19 (1-2) ◽  
pp. 229-236 ◽  
Author(s):  
Makram T. Suidan ◽  
Peter Fox ◽  
John T. Pfeffer
Keyword(s):  
Activated Carbon ◽  
Coal Gasification ◽  
Physical Adsorption ◽  
Oxygen Demand ◽  
Granular Activated Carbon ◽  
Anaerobic Treatment ◽  
Partial Replacement ◽  
Anaerobic Culture ◽  
Second Stage ◽  
Coal Gasification Wastewater

A sequence of unit processes consisting of a berl-saddle-packed anaerobic filter, an expanded-bed, granular activated carbon anaerobic reactor and an activated sludge nitrification system was employed for the treatment of synthetically prepared coal gasification wastewater. After acclimation, the coal gasification wastewater was fed to the treatment process train at three different chemical oxygen demand levels; these were 1,513. 3,027, and 7,567 mg/ℓ, respectively. No biological activity was observed in the first-stage filter, while excellent removal of organic matter was achieved in the second and third stages of the treatment systems. However, toxicity to the anaerobic culture in the second-stage reactor was observed during the second and third loading levels. This toxicity was overcome by employing a partial replacement schedule of the granular activated carbon medium in the reactor. This study represents an example of how biodegradation and physical adsorption may be successfully combined during the treatment of wastewaters containing toxic or inhibitory substances.

Start up of an anaerobic inverse turbulent bed reactor fed with wine distillery wastewater using pre-colonised bioparticles

2005 ◽  
Vol 51 (1) ◽  
pp. 153-158 ◽  
Author(s):  
C. Arnaiz ◽  
S. Elmaleh ◽  
J. Lebrato ◽  
R. Moletta
Keyword(s):  
Industrial Wastewater ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Biofilm Reactors ◽  
Start Up ◽  
Distillery Wastewater

The long start-up period of fluidized bed biofilm reactors is a serious obstacle for their wide installation in the anaerobic treatment of industrial wastewater. This paper presents the results of an anaerobic inverse turbulent bioreactor treating distillery wastewater during 117 days of operation at a laboratory scale. The pre-colonized bioparticles for this work were obtained from a similar reactor processing the same wastewater and which had a start-up period of 3 months. The system attained carbon removal efficiency rates between 70 and 92%, at an organic loading rate of 30.6 kg m+3 d+1 (chemical oxygen demand) with a hydraulic retention time of 11.1 h. The results obtained showed that the start-up period of this kind of reactors can be reduced by 3 using pre-colonized bioparticles.

Treatment of Anthranilic Acid in an Anaerobic Expanded Granular Sludge Bed Reactor at Low Concentrations

1999 ◽  
Vol 40 (8) ◽  
pp. 187-194 ◽  
Author(s):  
Elías Razo-Flores ◽  
Patrick Smulders ◽  
Francesc Prenafeta-Boldú ◽  
Gatze Lettinga ◽  
Jim A. Field
Keyword(s):  
Anthranilic Acid ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Organic Loading Rate ◽  
Reactor Operation ◽  
Batch Mode ◽  
Low Concentrations ◽  
Kinetic Calculations

The mineralization of anthranilic acid (2AB) as the only carbon and energy source was studied in batch and continuous conditions using methanogenic granular sludge. Under batch conditions in serum vials, 2AB (300 mg/l) was completely mineralized to methane within 55 days time. The experiment with the anaerobic continuous expanded granular sludge bed (EGSB) reactor was initially conducted at an upflow velocity (Vup) of 5 m/h, a hydraulic retention time (HRT) of 12 h and an organic loading rate (OLR) of 1.5 g chemical oxygen demand (COD)/l-d. After 102 days, 2AB was not degraded at all and the reactor operation was shifted to batch mode by recycling the effluent. After some days, 2AB was completely mineralized and accumulation of flocculent sludge was observed. Batch biodegradability assays demonstrated that this flocculent biomass had a higher specific biodegradation rate compared to the granular sludge. During EGSB reactor operation, the flocculent biomass which was not attached to the granules probably washed-out under the applied hydrodynamic conditions. When the EGSB reactor was operated at Vup of 2 m/h to favour the retention of the flocculent biomass, 2AB was mineralized even at influent concentrations as low as 140 mg COD/L. Kinetic calculations indicated that the sludge had an apparent Ks value for the mineralization of 2AB as low as 24 mg COD/l.

Factors affecting phosphorus removal in two biofilter system treating wastewater from car-washing facility

2000 ◽  
Vol 41 (4-5) ◽  
pp. 487-492 ◽  
Author(s):  
D. Pak ◽  
W. Chang
Keyword(s):  
Phosphorus Removal ◽  
Phosphorus Content ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Aerobic Condition ◽  
Suspended Solid ◽  
Nitrogen Loading ◽  
Operational Parameters ◽  
Factors Affecting ◽  
Biological Filter

A two-biofilter system operated under alternating anaerobic/aerobic conditions was tested to remove nutrient as well as organics from wastewater generated from car-washing facility. The wastewater was characterized by relatively low organic and high phosphorus content. The factors affecting phosphorus removal in the two-biofilter system were investigated. Operational parameters examined in this study were hydraulic retention time, organic, suspended solid and nitrogen loading rate. The factors affecting phosphorus removal in biological filter appeared to be influent COD, COD/T–P, BOD/COD, nitrogen, and SS/T–P. Nitrite and nitrate produced in the biofilter in aerobic condition affected phosphorus removal by the two-biofilter system. The biomass wasted during backwash procedure also affected total phosphorus removal by the system.

scholarly journals The Start-Up of Continuous Biohydrogen Production from Cheese Whey: Comparison of Inoculum Pretreatment Methods and Reactors with Moving and Fixed Polyurethane Carriers

2021 ◽  
Vol 11 (2) ◽  
pp. 510
Author(s):  
Elza R. Mikheeva ◽  
Inna V. Katraeva ◽  
Andrey A. Kovalev ◽  
Dmitriy A. Kovalev ◽  
Alla N. Nozhevnikova ◽  
...  
Keyword(s):  
Cheese Whey ◽  
Hydraulic Retention Time ◽  
Continuous Production ◽  
Oxygen Demand ◽  
Organic Load ◽  
Anaerobic Sludge ◽  
Acid Pretreatment ◽  
Methanogenic Activity ◽  
Start Up ◽  
Load Rate

This article presents the results of the start-up of continuous production of biohydrogen from cheese whey (CW) in an anaerobic filter (AF) and anaerobic fluidized bed (AFB) with a polyurethane carrier. Heat and acid pretreatments were used for the inactivation of hydrogen-scavengers in the inoculum (mesophilic and thermophilic anaerobic sludge). Acid pretreatment was effective for thermophilic anaerobic sludge to suppress methanogenic activity, and heat treatment was effective for mesophilic anaerobic sludge. Maximum specific yields of hydrogen, namely 178 mL/g chemical oxygen demand (COD) and 149 mL/g COD for AFB and AF, respectively, were obtained at the hydraulic retention time (HRT) of 4.5 days and organic load rate (OLR) of 6.61 kg COD/(m3 day). At the same time, the maximum hydrogen production rates of 1.28 and 1.9 NL/(L day) for AF and AFB, respectively, were obtained at the HRT of 2.02 days and OLR of 14.88 kg COD/(m3 day). At the phylum level, the dominant taxa were Firmicutes (65% in AF and 60% in AFB), and at the genus level, Lactobacillus (40% in AF and 43% in AFB) and Bifidobacterium (24% in AF and 30% in AFB).

scholarly journals Development of downflow hanging sponge (DHS) reactor as post treatment of existing combined anaerobic tank treating natural rubber processing wastewater

2016 ◽  
Vol 75 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Takahiro Watari ◽  
Trung Cuong Mai ◽  
Daisuke Tanikawa ◽  
Yuga Hirakata ◽  
Masashi Hatamoto ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Nitrogen Loading ◽  
Post Treatment ◽  
Organic Loading Rate ◽  
Anammox Bacteria ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
Reactor Performance

Conventional aerated tank technology is widely applied for post treatment of natural rubber processing wastewater in Southeast Asia; however, a long hydraulic retention time (HRT) is required and the effluent standards are exceeded. In this study, a downflow hanging sponge (DHS) reactor was installed as post treatment of anaerobic tank effluent in a natural rubber factory in South Vietnam and the process performance was evaluated. The DHS reactor demonstrated removal efficiencies of 64.2 ± 7.5% and 55.3 ± 19.2% for total chemical oxygen demand (COD) and total nitrogen, respectively, with an organic loading rate of 0.97 ± 0.03 kg-COD m−3 day−1 and a nitrogen loading rate of 0.57 ± 0.21 kg-N m−3 day−1. 16S rRNA gene sequencing analysis of the sludge retained in the DHS also corresponded to the result of reactor performance, and both nitrifying and denitrifying bacteria were detected in the sponge carrier. In addition, anammox bacteria was found in the retained sludge. The DHS reactor reduced the HRT of 30 days to 4.8 h compared with the existing algal tank. This result indicates that the DHS reactor could be an appropriate post treatment for the existing anaerobic tank for natural rubber processing wastewater treatment.

Sign in / Sign up

Export Citation Format

Share Document