Impact of a metabolic uncoupler, 2,4-dichlorophenol on minimization of activated sludge production in membrane bioreactor

2010 ◽  
Vol 62 (6) ◽  
pp. 1379-1385 ◽  
Author(s):  
Lin Song ◽  
Jiang Wenju ◽  
Tang Qiong ◽  
Li Yaozhong
Keyword(s):  
Activated Sludge ◽  
Specific Growth ◽  
Removal Rate ◽  
Significant Inhibition ◽  
Membrane Bioreactors ◽  
Cod Removal ◽  
Slight Reduction ◽  
Floc Size ◽  
Cod Removal Rate ◽  
Sludge Production

This study investigated the effects of 2,4-dichlorophenol on reduction of activated sludge in membrane bioreactors. Significant inhibition on sludge growth and slight reduction in COD removal were observed at higher 2,4-dichlorophenol dosages. The deviation between relative specific COD removal rate (q/q0) and relative specific growth rate (μ/μ0) suggested that a minimum 2,4-dichlorophenol concentration was required for uncoupling of anabolism and catabolism. With the increase of the dosage of 2,4-dichlorophenol, stepwise improvement of biomass bioactivity and the reduction in activated sludge production were achieved simultaneously. Compared with the control bioreactor, the peak distribution of floc size in the 2,4-dichlorophenol added bioreactor shifted to a range of smaller floc size. Besides, addition of 2,4-dichlorophenol caused little variation of microorganism community structure and SVI value of the sludge. After 24-hour operation, the residue 2,4-dichlorophenol concentration in the bioreactors was reduced to a negligible level.

Anaerobic Biological Treatment of Saline Municipal Wastewater by UASB

2014 ◽  
Vol 1030-1032 ◽  
pp. 292-295
Author(s):  
Tao Mo Zhao ◽  
Feng Gao ◽  
Wei Hong Jin ◽  
Peng Gao
Keyword(s):  
Activated Sludge ◽  
Biological Treatment ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Cod Removal ◽  
Saline Wastewater ◽  
Anaerobic Reactor ◽  
Good Ability ◽  
Cod Removal Rate

In this paper, saline wastewater was treated by using the UASB anaerobic reactor. The hydraulic retention time (HRT) of the reactor was controlled at 12 h. Research results shows that, the anaerobic activated sludge can effectively treat the saline wastewater. When the influent salinity was 1%, the corresponding COD removal rate of the reactor was 83.3%. In the following study, the influent salinity increased to 2% and 3% step-by-step. The result shows that the COD removal efficiency of the reactor changed little. The COD reduction of the reactor was 87.6% when the influent salinity was 2%. The COD removal rate changed to 85.2% when the influent salinity increased to 3%. The removal rate of NH4+-N and PO43-P also changed little when the influent salinity of the reactor increased form 1% to 3%. It shows that anaerobic activated sludge has good ability of salt tolerance.

Research of 6-Nitry Industrial Wastewater Treatment by Coagulation-Fenton Oxidation

2012 ◽  
Vol 518-523 ◽  
pp. 2745-2748
Author(s):  
Ling Yan Ren ◽  
Gang Xu
Keyword(s):  
Treatment Effect ◽  
Industrial Wastewater ◽  
Removal Rate ◽  
Sulfate Solution ◽  
Cod Removal ◽  
Fenton Oxidation ◽  
Fenton Reagent ◽  
Oxidation Treatment ◽  
Cod Removal Rate ◽  
Solution Acidity

The paper adopted Coagulation-Fenton Oxidation Method on treating the wastewater of 6-nitro-1,2 diazonium oxygroup naphthalene-4-sulfoacid production process (i.e. 6-nitry wastewater), introduced the treatment effect of the combined technology used on 6-nitry wastewater, and studied the factors influencing the treatment effect, to determine the reasonable parameters of the technology on treating 6-nitry wastewater. The results showed that Using polyaluminium chloride (mass fraction 2%) as flocculant for treating 6-nitry wastewater, the COD removal rate reached up to 48.7%; Making Fenton reagent oxidation treatment on coagulation yielding water, under the best conditions for solution acidity controlled at pH3 or so, in the 100 mL wastewater, 30% hydrogen peroxide was 5.0 mL, 0.5 mol/L ferrous sulfate solution was 4.0 mL, reaction time was 60 min, the COD removal rate could reach 98% or more.

Study on Spray on Degradation of TNT-RDX Explosives Wastewater by Synergetic Ozonation

2013 ◽  
Vol 726-731 ◽  
pp. 2316-2319
Author(s):  
Hai Xia Duan
Keyword(s):  
Gas Phase ◽  
Removal Rate ◽  
Droplet Diameter ◽  
Cod Removal ◽  
The Self ◽  
Cod Removal Rate

TNT-RDX wastewater is hard to biodegrade and highly toxic. The self-made reactor was used to degrade the wastewater, spray and the conditions of droplet diameter, number of nozzle, spray height were clearly observed. The results show that the average COD removal rate of TNT-RDX wastewater was 69.6%.The spray conditions can improve the dispersion of the wastewater and increase the use of the residual ozone in gas phase. Keywords: Spray; TNT-RDX wastewater; ozone; UV; GAC

scholarly journals Study of COD Removal Rate on a Sequencing Batch Reactor (SBR) Treating Tapioca Wastewater

2019 ◽  
Vol 38 (3) ◽  
pp. 243
Author(s):  
Happy Mulyani ◽  
Gregorius Prima Indra Budianto ◽  
Margono Margono ◽  
Mujtahid Kaavessina
Keyword(s):  
Wastewater Treatment ◽  
Sequencing Batch Reactor ◽  
Removal Rate ◽  
Batch Reactor ◽  
Cod Removal ◽  
Operation Condition ◽  
Effluent Quality ◽  
Aeration Time ◽  
Standard Quality ◽  
Cod Removal Rate

Industrial wastewater treatment using Sequencing Batch Reactor (SBR) can improve effluent quality at lower cost than that obtained by other biological treatment methods. Further optimization is still required to enhance effluent quality until it meets standard quality and to reduce the operating cost of treatment of high strength organic wastewater. The purpose of this research was to determine the effect of pretreatment (pH adjustment and prechlorination) and aeration time on effluent quality and COD removal rate in tapioca wastewater treatment using SBR. Pretreatment was done by (1) adjustment of tapioca wastewater pH to control (4.92), 7, and 8, and (2) tapioca wastewater prechlorination at pH 8 during hour using calcium hypochlorite in variation dosages 0, 2, 4, 6 mg/L Cl2, SBR operation was conducted according to following steps: (1) Filling of pre-treated wastewater into a bioreactor during 1 hour, and (2) aeration of the mixture of tapioca wastewater and activated sludge during 8 hours. Effluent sample was collected at every 2-hours aeration for COD analysis. COD removal rate mathematical formula was got by first deriving the best fit function between aeration time and COD. Optimum aeration time resulting in no COD removal rate. The value of COD effluent and its removal rate in optimum aeration time was used to determine the recommended of operation condition of pretreatment. Research result shows that chosen pH operation condition is pH 8. Prechorination can make effluent quality which meets standard quality and highest COD removal rate. The chosen Cl2 dosage is 6 mg/L.

A Study of Fenton’s Oxidation Pretreatment on Dye Wastewater Containing Acetic Acid

2014 ◽  
Vol 1044-1045 ◽  
pp. 215-218
Author(s):  
Xian Huan Qiu ◽  
Hai Yu ◽  
Peng Fei Deng
Keyword(s):  
Acetic Acid ◽  
Processing Time ◽  
Ph Value ◽  
Removal Rate ◽  
Cod Removal ◽  
Dye Wastewater ◽  
Fenton’S Oxidation ◽  
Effects Of Ph ◽  
Cod Removal Rate ◽  
Fenton's Oxidation

In the presence of acetic acid, the effects of pH, processing time, addition of Fe2+ and H2O2 on dye wastewater treatment were studied. Experimental results showed that in the presence of acetic acid, when the pH value was 4, the processing time was 30.0min, addition of ferrous sulfate was 4.8g/L, and addition of hydrogen peroxide was 56mL/L, the treatment effect was the best, COD removal rate reached 51.0%. Further studied of the effect of the presence of acetic acid on Fenton’s oxidation of dye wastewater, the results showed that without of acetic acid, the COD removal rate was higher than that with acetic acid. And the effect of Fenton's reagent on oxidation of dye substances was interfered by the presence of acetic acid.

Anaerobic digestion of waste activated sludge combined with ozone post-treatment and recycling

2003 ◽  
Vol 48 (4) ◽  
pp. 61-68 ◽  
Author(s):  
A. Battimelli ◽  
C. Millet ◽  
J.P. Delgenès ◽  
R. Moletta
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Removal Rate ◽  
Operating Conditions ◽  
Cod Removal ◽  
Process Efficiency ◽  
Recycling Rate ◽  
Waste Activated Sludge ◽  
Digested Sludge ◽  
Combined Process

The aim of the study was to determine the performances of a combined ozone/anaerobic digestion system for waste activated sludge reduction. The objective was the estimation of the process efficiency and stability when keeping constant influent flow while increasing recycled chemically treated flow. The ozonation step consisted in a partial oxidation (0.16 g O3/g SS) of the anaerobic mesophilic digested sludge. Chemical treatment of digested sludge resulted in a threefold COD solubilization and a decrease of SS of 22%. Some of the advantages of digested sludge ozonation were: deodorization, better settlement and a reduction in viscosity. However there were drawbacks: foaming during ozonation and, at high ozone doses, poorer filterability. The anaerobic digestion was carried out over 6 months with an increasing recycling of ozonated flow. Suspended solids removal rate and COD removal rate were compared with initial operating conditions for the biological reactor and the whole combined process. The optimum recycling rate was 25% with increases of SS removal and COD removal of 54% and 66% respectively when considering the combined process; corresponding to a decrease of the hydraulic retention time from 24 days to 19 days.

Aerobic granulation in a sequencing batch reactor (SBR) for industrial wastewater treatment

2005 ◽  
Vol 52 (10-11) ◽  
pp. 335-343 ◽  
Author(s):  
M. Inizan ◽  
A. Freval ◽  
J. Cigana ◽  
J. Meinhold
Keyword(s):  
Industrial Wastewater ◽  
Removal Rate ◽  
Batch Reactor ◽  
Experimental Tests ◽  
Cod Removal ◽  
High Concentration ◽  
Granule Formation ◽  
Aerobic Granulation ◽  
Cod Removal Rate ◽  
Set Up

Aerobic granulation seems to be an a attractive process for COD removal from industrial wastewater, characterised by a high content of soluble organic compounds. In order to evaluate the practical aspects of the process, comparative experimental tests are performed on synthetic and on industrial wastewater, originating from pharmaceutical industry. Two pilot plants are operated as sequencing batch bubble columns. Focus was put on the feasibility of the process for high COD removal and on its operational procedure. For both wastewaters, a rapid formation of aerobic granules is observed along with a high COD removal rate. Granule characteristics are quite similar with respect to the two types of wastewater. It seems that filamentous bacteria are part of the granule structure and that phosphorus precipitation can play an important role in granule formation. For both wastewaters similar removal performances for dissolved biodegradable COD are observed (> 95%). However, a relatively high concentration of suspended solids in the outlet deteriorates the performance with regard to total COD removal. Biomass detachment seems to play a non-negligible role in the current set-up. After a stable operational phase the variation of the pharmaceutical wastewater caused a destabilisation and loss of the granules, despite the control for balanced nutrient supply. The first results with real industrial wastewater demonstrate the feasibility of this innovative process. However, special attention has to be paid to the critical aspects such as granule stability as well as the economic competitiveness, which both will need further investigation and evaluation.

Synergetic Degradation of Zidovudine Wastewater by Ultrasonic and Iron-Carbon Micro-Electrolysis

2011 ◽  
Vol 347-353 ◽  
pp. 1949-1952 ◽  
Author(s):  
Liang Li ◽  
Bing Zhe Xu ◽  
Chang Yu Lin ◽  
Xiao Min Hu
Keyword(s):  
Reaction Time ◽  
Degradation Rate ◽  
Removal Rate ◽  
Cod Removal ◽  
Mass Ratio ◽  
Initial Ph ◽  
Cod Removal Rate

Zidovudine wastewater is difficult to biodegradation due to high COD and toxicity. The synergetic treatment of Zidovudine wastewater by Ultrasonic and iron-carbon micro-electrolysis technology was studied. The influence of initial pH, reaction time, mass ratio of iron and carbon and mass ratio of iron and water on degradation rate of COD was researched. The result showed that the COD removal rate was only about 54.3% and the degradation speed is very slow when iron-carbon micro-electrolysis treated Zidovudine wastewater　separately. However, when ultrasonic synergy micro-electrolysis to treat Zidovudine wastewater, the COD removal rate could was up to 85% and the reaction time was also decreased. Moreover, the BOD5 / COD rose from 0.15 to 0.35, which meant the wastewater became easily biodegradable.

Degradation of Landfill Leachate by Ultrasound/Ultraviolet - Aged Refuse Bioreactor Combined Process

2013 ◽  
Vol 448-453 ◽  
pp. 532-535
Author(s):  
Bin Liu ◽  
Xu Ya Peng ◽  
Hua Zhao ◽  
Qi Tian
Keyword(s):  
Landfill Leachate ◽  
Biological Treatment ◽  
Impact Load ◽  
Removal Rate ◽  
Cod Removal ◽  
Combined Process ◽  
Aged Refuse ◽  
Optimum Wavelength ◽  
Cod Removal Rate ◽  
Strong Capacity

The biodegradability of aged landfill leachate is low, and the treatment effects of common processes are very poor. This paper explored the effects of the Ultrasound/Ultraviolet - Aged Refuse Bioreactor combined process on aged landfill leachate. The main results were as follows: 1The optimum power of ultrasound was 100 W, and the optimum wavelength of ultraviolet was 254 nm. The removal rate of COD was 27.33% and the value of BOD/COD ratio was increased from 0.1 to 0.35 after the treatment of Ultrasound/Ultraviolet process. Therefore, the biodegradability of the leachate was improved, which might meet the demand of subsequent biological treatment. 2The COD removal rates of the two-stage series aged refuse bioreactor were both kept above 50% during the experiment and this process had a strong capacity of resistance to impact load. 3The COD removal rate of the combined process was over 80% as a whole without any pretreatment, and it has positive significance for the treatment of aged leachate.

Research for Treating Avermectin Wastewater with UASB Technique

2011 ◽  
Vol 356-360 ◽  
pp. 1281-1284
Author(s):  
Yan Hong Chang ◽  
Hui Tao Feng ◽  
Hui Luo ◽  
San Jian Ma
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Cod Removal ◽  
Stable Phase ◽  
Volume Load ◽  
Cod Removal Rate

The avermectin wastewater was treated with UASB technique. The paper was focused mainly on the removal rate of COD and the change of ammonia nitrogen of influent and effluent wastewater in the first running stage. At the stable phase of anaerobic operation, the removal rate of COD could be stabilized at 85% when the influent volume load was 9.21 kg/(m3•d), and the effluent COD was about 1400 mg/L. As for ammonia nitrogen concentration of influent and effluent wastewater, in the first 50 days, the former was larger than the latter, after then, it was opposite. In the condition of same volume load but different hydraulic retention time (COD concentration of influent being different), COD removal rate kept almost the same. In the second running stage, the influent COD volume load reached 9.21 kg/(m3•d) at the 16th day, with the COD removal rate being around 87%.

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