Adsorption removal of tetracycline from aqueous solution by anaerobic granular sludge: equilibrium and kinetic studies

2013 ◽  
Vol 67 (7) ◽  
pp. 1490-1496 ◽  
Author(s):  
Ke Li ◽  
Feng Ji ◽  
Yuanlu Liu ◽  
Zilin Tong ◽  
Xinmin Zhan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Adsorption Process ◽  
Granular Sludge ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Batch Adsorption ◽  
Anaerobic Granular Sludge ◽  
High Concentration ◽  
Animal Wastewater

High concentration animal wastewater is often contaminated by tetracycline and an upflow anaerobic sludge bioreactor (UASB) with granular sludge is often used to treat the wastewater. The investigation of the adsorption process of tetracycline on anaerobic granular sludge during anaerobic digestion of animal wastewater will increase the understanding of antibiotics behavior in the UASB reactor. In this study, the effects of initial pH, humic acid concentration, and temperature on the removal of tetracycline by anaerobic granular sludge from aqueous solution were investigated using the batch adsorption technique in 100 mL flasks with 75 mL of work volume. The results show that the highest removal efficiency of 93.0% was achieved around pH 3.0 and the removal efficiency at the neutral pH range (pH 6.0–8.0) is about 91.5%. The thermodynamic analysis indicates that the adsorption is a spontaneous and endothermic process. The adsorption kinetics followed the pseudo-second-order equation. The adsorption isotherms analysis indicates that the Langmuir model is better than the Freundlich model for the description of the adsorption process and confirms the result of thermodynamics analysis. The maximum adsorption capacities were 2.984, 4.108 and 4.618 mg/g at 25, 35 and 45 °C, respectively. These results provide useful information for understanding the fate and transformation of tetracycline in a UASB digestion system and improving the management of tetracycline contaminated animal wastewater.

Acid Endurance and Sorption of Zn2+ of Anaerobic Granular Sludge Acclimated by Flue Gas Pretreatment Wastewater

2013 ◽  
Vol 634-638 ◽  
pp. 182-186
Author(s):  
Juan Wang ◽  
Qin Zhong
Keyword(s):  
Flue Gas ◽  
Ph Value ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Anaerobic Granular Sludge ◽  
Methanogenic Activity ◽  
Activity Inhibition ◽  
Anaerobic Sludge Blanket

With the aim to use anaerobic granular sludge, the methanogenic activity inhibition and recovery of anaerobic granular sludge from an industrial anaerobic reactor (s1) were investigated by measuring the methane volume at low pH. A lab-scale upflow anaerobic sludge blanket (UASB) reactor was inoculated with s1.s1 was used to remove Zn2+ in wastewater. The results show that activity of s1 is similar when the pH value is 6.5 to 7.0. The methane volume is obviously decreased when the pH value is 6.0. The activity is completely inhibited when the pH value is 4.5. The activity is fully recovered when the pH is above 6.5 and hardly recovers when the pH fell to 4.5. The main Zn2+ removal mechanism is chemical adsorption.

Removal efficiency and methanogenic activity profiles in a pilot-scale UASB reactor treating settled sewage at moderate temperatures

2002 ◽  
Vol 45 (10) ◽  
pp. 243-248 ◽  
Author(s):  
L. Seghezzo ◽  
R.G. Guerra ◽  
S.M. González ◽  
A.P. Trupiano ◽  
M.E. Figueroa ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Pilot Scale ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Methanogenic Activity

The performance of a sewage treatment system consisting of a settler followed by an Upflow Anaerobic Sludge Bed (UASB) reactor is described. Mean ambient and sewage temperature were 16.5 and 21.6°C, respectively. Total Chemical Oxygen Demand (CODt) concentration averaged 224.2 and 152.6 mg/L, for raw and settled sewage, respectively. The effluent concentration was 68.5 mgCODt/L. Total and suspended COD removal efficiencies of approximately 70 and 80%, respectively, have been observed in the system at a mean Hydraulic Retention Time (HRT) of 2 + 5 h. Maximum COD removal efficiency was achieved in the UASB reactor when upflow velocity (Vup) was 0.43 m/h (HRT = 6 h). Mean Specific Methanogenic Activity (SMA) and Volatile Suspended Solids (VSS) concentration in the granular sludge bed were 0.11 gCOD-CH4/gVSS.d and 30.0 gVSS/Lsludge, respectively. SMA was inversely related to VSS concentration, and both parameters varied along the sludge bed height. The Solids Retention Time (SRT) in the reactor was 450 days. Sludge characteristics have not been affected by changes of up to one month in Vup in the range 0.28–0.85 m/h (HRT 3–9 h). This system or two UASB reactors in series could be an alternative for sewage treatment under moderate temperature conditions.

scholarly journals Surface Modification of Powdered Maize Husk with Sodium Hydroxide for Enhanced Adsorption of Pb(II) Ions from Aqueous Solution

2020 ◽  
Vol 9 (1) ◽  
pp. 95-104
Keyword(s):  
Aqueous Solution ◽  
Sodium Hydroxide ◽  
Removal Efficiency ◽  
Adsorption Process ◽  
Lead Ions ◽  
Solution Temperature ◽  
Lead Ion ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorbent Dose

The impact of sodium hydroxide pretreatment of maize husk on its lead ion removal efficiency was investigated. Pretreatment of maize husk with this alkali increased its surface area and porosity from 528.74 m2/g and 0.477 cm3/g to 721.54 m2/g and 0.642 cm3/g, respectively. Batch adsorption studies were carried out to evaluate the effects of initial pH, adsorbent dose, initial lead ion concentration, initial solution temperature, and contact time on the adsorption process. The maximum removal efficiency of maize husk at pH 5 and adsorbent dose 2 g/L was 62.85 %, which increased to 82.84 % after pretreatment and was attained in 15 min. The adsorption data for the natural and pretreated maize husk were best fitted in the Freundlich isotherm model, with their adsorption intensity (n) having values >1, which indicated that lead ion adsorption onto the adsorbent types was a favorable physical process. The adsorption of lead ions onto the adsorbents followed the pseudo-first-order kinetic model. The experimental adsorption capacities of maize husk (31.43 mg/g) and its modified form (41.22 mg/g) were very close to those obtained from this model (31.03 mg/g and 40.65 mg/g respectively). The ΔH and ΔG values of the adsorption process showed that the adsorption of lead ions by both adsorbents was an endothermic process and occurred spontaneously. Alkali pretreated maize husk can therefore be used as a cheap adsorbent to remove lead ions from aqueous solution.

scholarly journals Adsorption of Iron with Biosorbents derived from Longan Peel, Pomelo Peel and Jackfruit Peel

2021 ◽  
Vol 945 (1) ◽  
pp. 012057
Author(s):  
Yi Jun Chai ◽  
Yee Sern Ng ◽  
Katrina Pui Yee Shak ◽  
Law Yong Ng
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Adsorption Process ◽  
Low Cost ◽  
Batch Adsorption ◽  
Pomelo Peel ◽  
Positive Ions ◽  
Carboxylate Groups ◽  
The World ◽  
Initial Ph

Abstract High iron (Fe2+) concentration in groundwater is a severe issue in many regions of the world. This study attempts to investigate the effectiveness of biosorbents derived from longan peel (LP), pomelo peel (PP) and jackfruit peel (JP) for the adsorption of Fe2+ from aqueous solution in various forms. A batch adsorption study was carried out with an initial Fe2+ concentration of 10 mg/L for 2 h. The results showed that the highest removal efficiency was achieved for PP and its biochar at 97.38% and 99.45%, respectively. High removal efficiency implied that PP contained favourable characteristics for the adsorption of Fe2+. Under the scanning electron microscope (SEM), the surface structure of PP displayed visible dimensions with a relatively large pore size compared with LP and JP. Characterisation study using Fourier-transform infrared spectroscopy (FTIR) reveals that the carboxylate groups and ester carbonyl band participated in the adsorption process. At higher initial pH of 5.83, adsorption of Fe2+ using PP gives higher removal efficiency due to lower competition on electrostatic interaction between positive ions in the solution and the surface of biosorbents. Furthermore, adsorption uptake of 83.0 mg/g was attainable with an initial concentration of 100 mg/L. This study has proven the feasibility of PP as a low cost biosorbents for removing Fe2+ in an aqueous solution.

Toxicity of Sulfite and Cadmium to Anaerobic Granular Sludge

1994 ◽  
Vol 29 (4) ◽  
pp. 581-598
Author(s):  
C.F. Shew ◽  
N. Kosaric
Keyword(s):  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Shock Load ◽  
Anaerobic Sludge ◽  
Anaerobic Granular Sludge ◽  
Scanning Electron Micrographs ◽  
Bacterial Growth Rate ◽  
Digestion Rate ◽  
Sulfate Reducing ◽  
Load Conditions

Abstract Toxicity of sulfite (Na2SO3) and cadmium (CdCl2) ions to anaerobic granular sludge was investigated in 1.2 litre bench-scale upflow anaerobic sludge blanket (UASB) reactors during process acclimation and shock load conditions. Minimal sulfite toxicity was observed under gradual and shock load conditions at sulfite concentrations of up to 1000 mg S/L if proper acclimation was allowed to occur. No long-term toxic effects were observed although the COD digestion rate was temporarily inhibited by shock load of sulfite. Scanning electron micrographs indicated that more sulfate-reducing bacteria were present in the granules developed in the reactors with sulfite supplement although rod-shaped Methanosaeta-like bacteria were still dominant. High bacterial growth rate was observed in the reactors which were supplied with the feed containing sulfite. The COD digestion rate was inhibited at a cadmium loading rate of 2.4 g Cd per day under both acclimation and shock load conditions. Acclimation did not seem to improve the bacteria to tolerate the toxicity of cadmium. The concentration of free cadmium was very low in the reactors under normal conditions, but increased rapidly when the COD digestion in the reactors ceased. The bacteria could not be reactivated after inhibited by cadmium. When reactors were operated at low specific COD loading rates, more inorganic precipitates were formed inside the granules which consequently settled faster.

Utilisation of Biomass and Hybrid Biochar from Elephant Grass and Low Density Polyethylene for the Competitive Adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) from Aqueous Media

2020 ◽  
Vol 13 ◽  
Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Removal Efficiency ◽  
Contact Time ◽  
Competitive Adsorption ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Polluted Water ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Elephant Grass

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.

scholarly journals Microbial Diversity Dynamics in a Methanogenic-Sulfidogenic UASB Reactor

2021 ◽  
Vol 18 (3) ◽  
pp. 1305
Author(s):  
E. Fernández-Palacios ◽  
Xudong Zhou ◽  
Mabel Mora ◽  
David Gabriel
Keyword(s):  
Paper Industry ◽  
Chemical Species ◽  
Methanogenic Archaea ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Rrna Gene ◽  
Sulfate Reducing ◽  
Long Run

In this study, the long-term performance and microbial dynamics of an Upflow Anaerobic Sludge Blanket (UASB) reactor targeting sulfate reduction in a SOx emissions treatment system were assessed using crude glycerol as organic carbon source and electron donor under constant S and C loading rates. The reactor was inoculated with granular sludge obtained from a pulp and paper industry and fed at a constant inlet sulfate concentration of 250 mg S-SO42−L−1 and a constant C/S ratio of 1.5 ± 0.3 g Cg−1 S for over 500 days. Apart from the regular analysis of chemical species, Illumina analyses of the 16S rRNA gene were used to study the dynamics of the bacterial community along with the whole operation. The reactor was sampled along the operation to monitor its diversity and the changes in targeted species to gain insight into the performance of the sulfidogenic UASB. Moreover, studies on the stratification of the sludge bed were performed by sampling at different reactor heights. Shifts in the UASB performance correlated well with the main shifts in microbial communities of interest. A progressive loss of the methanogenic capacity towards a fully sulfidogenic UASB was explained by a progressive wash-out of methanogenic Archaea, which were outcompeted by sulfate-reducing bacteria. Desulfovibrio was found as the main sulfate-reducing genus in the reactor along time. A progressive reduction in the sulfidogenic capacity of the UASB was found in the long run due to the accumulation of a slime-like substance in the UASB.

scholarly journals Evaluation of removal efficiency of residual diclofenac in aqueous solution by nanocomposite tungsten-carbon using design of experiment

2017 ◽  
Vol 76 (6) ◽  
pp. 1466-1473 ◽  
Author(s):  
M. H. Salmani ◽  
M. Mokhtari ◽  
Z. Raeisi ◽  
M. H. Ehrampoush ◽  
H. A. Sadeghian
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Design Of Experiment ◽  
High Efficiency ◽  
Carbon Powder ◽  
Batch Adsorption ◽  
Effective Parameters ◽  
Initial Concentration ◽  
Carbon Nanocomposite ◽  
Maximum Removal

Wastewater containing pharmaceutical residual components must be treated before being discharged to the environment. This study was conducted to investigate the efficiency of tungsten-carbon nanocomposite in diclofenac removal using design of experiment (DOE). The 27 batch adsorption experiments were done by choosing three effective parameters (pH, adsorbent dose, and initial concentration) at three levels. The nanocomposite was prepared by tungsten oxide and activated carbon powder in a ratio of 1 to 4 mass. The remaining concentration of diclofenac was measured by a spectrometer with adding reagents of 2, 2′-bipyridine, and ferric chloride. Analysis of variance (ANOVA) was applied to determine the main and interaction effects. The equilibrium time for removal process was determined as 30 min. It was observed that the pH had the lowest influence on the removal efficiency of diclofenac. Nanocomposite gave a high removal at low concentration of 5.0 mg/L. The maximum removal for an initial concentration of 5.0 mg/L was 88.0% at contact time of 30 min. The results of ANOVA showed that adsorbent mass was among the most effective variables. Using DOE as an efficient method revealed that tungsten-carbon nanocomposite has high efficiency in the removal of residual diclofenac from the aqueous solution.

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