Study on Chemical Wastewater Treatment with Many-Point-Water-Inflow Biological Reaction Tank

2012 ◽  
Vol 518-523 ◽  
pp. 2825-2828
Author(s):  
Fang Li ◽  
Dan Hao
Keyword(s):  
Activated Sludge ◽  
Treatment Effect ◽  
Removal Rate ◽  
Trace Element Content ◽  
Water Inflow ◽  
Good Effect ◽  
Aeration Tank ◽  
Active Sludge ◽  
Cod Removal Rate ◽  
Sludge Concentration

The composition of mixed chemical wastewater is more complex and biodegradability of its is bad, biochemical treatment effect should be further improved. Many-point-water-inflow bioreactor used in this experiment, through controlling hydraulic retention time(HRT), concentration of active sludge of the aeration tank, trace element content and so on, gets a better treatment effect. When water temperature is 25°C, HRT is 5h, 10h, 15h, 20h, 25h,COD removal rate is 60.37%, 82.62%, 89.44% , 91.02%,91.07%. According to the iron content of influent, plus 0.5mg/L ferrous sulfate into influent, the removal rate of COD is increased , activated sludge floc of the sedimentation tank is denser and settling. By changing the activated sludge return ratio to change the activated sludge concentration of the bioreactor, experiments shows that the removal rate of organic matter is better with the activated sludge concentration about 4000-5000mg/L. Influent qualities indicate that this biological treatment has good effect on mixed chemical wastewater.

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.

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.

Preparation of Composite Carrier Material Immobilized Activated Sludge and Application in Treating Wastewater

2010 ◽  
Vol 113-116 ◽  
pp. 301-304 ◽  
Author(s):  
Qian Nie ◽  
Fang Gu
Keyword(s):  
Mass Transfer ◽  
Polyvinyl Alcohol ◽  
Activated Sludge ◽  
Removal Rate ◽  
Transfer Property ◽  
Carrier Material ◽  
Preparation Conditions ◽  
Cod Removal Rate ◽  
Oil Wastewater ◽  
Composite Carrier

The optimum preparation conditions of polyvinyl alcohol (PVA) immobilized activated sludge are investigated, the results show that the concentration of the entrapping agents PVA is 10%(W/V), the mass ration of the activated sludge and entrapping agents is 1∶1(W/V) and the crosslinking time is 24 h. Pelletability and mass transfer property of immobilized activated sludge are improved by adding 1% sodium alginate (SA) into entrapping agents, the intensity of immobilized activated sludge and COD removal rate of oil wastewater can be increased simultaneously by using inorganic composited carrier material.

Experimental Advancements of Wastewater Disposal in Coal Chemical Industry by Yeasts

2014 ◽  
Vol 1073-1076 ◽  
pp. 941-948
Author(s):  
Li Li Wang ◽  
Qian Yang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chemical Industry ◽  
Ph Value ◽  
Removal Rate ◽  
Cod Removal ◽  
Good Effect ◽  
Coking Wastewater ◽  
Torula Yeast ◽  
N Removal ◽  
Cod Removal Rate

The research in this paper focuses on improving the COD removal rate of the coking wastewater and the NH3-N removal rate and thus diversifying measures to dispose microbial floras in wastewater from the coal chemical industry. The means of adding nutrients, acid treatment and coagulation sedimentation react synergistically to dispose the organic contaminants in the coking wastewater. We attempted to combine Saccharomyces cerevisiae, Torula yeast, tropical Candida mycoderma, etc. to exploit the respective advantages to the full and improve the disposal effect. According to the COD sample (27000-30000) and NH3-N (2500-3000) offered by the client company, the COD removal rate ranged from 24.2% to 31.8% in the mixed experiment group of Saccharomyces cerevisiae and Torula yeast, with NH3-N removal rate from 63.5% to 69.6%. Obviously, the NH3-N removal rate produced good effect. Meanwhile, the COD removal rate ranged form 35.3% to 41.8% in the experiment group only adjusting PH value and the NH3-N removal rate ranged from 40.2% to 50.2%. It is obvious that NH3-N removal rate is influenced by the amount of bacterial strain.

scholarly journals Aerobic and Anaerobic Biodegradability of Organophosphates in Activated Sludge Derived From Kitchen Garbage Biomass and Agricultural Residues

2021 ◽  
Vol 9 ◽  
Author(s):  
Xingfeng Yang ◽  
Deling Fan ◽  
Wen Gu ◽  
Jining Liu ◽  
Lili Shi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Electron Donor ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Agricultural Residues ◽  
Ionic Surfactant ◽  
Adaptation Period ◽  
Active Sludge ◽  
Fe Powder ◽  
Aerobic And Anaerobic

Organophosphates (also known as organophosphate esters, OPEs) have in recent years been found to be significant pollutants in both aerobic and anaerobic activated sludge. Food waste, such as kitchen garbage and agricultural residues, can be used as co-substrates to treat the active sludge in sewage treatment plants (STPs). We investigated the biodegradability of nine OPEs derived from kitchen garbage biomass and agricultural residues under different conditions. Under anaerobic conditions, the rate of removal of triphenyl ester OPEs was significantly higher than that of chloride and alkyl OPEs. The addition of FeCl3 and Fe powder increased the rate of degradation of triphenyl ester OPEs, with a DT50 for triphenyl ester OPEs of 1.7–3.8 d for FeCl3 and 1.3–4.7 d for Fe powder, compared to a DT50 of 4.3–6.9 d for the blank control. Addition of an electron donor and a rhamnolipid increased the rate of removal of chlorinated OPEs, with DT50 values for tris(2-carboxyethyl)phosphine) (TCEP) and tris(1,3-dichloroisopropyl)phosphate (TDCPP) of 18.4 and 10.0 d, respectively, following addition of the electron donor, and 13.7 and 3.0 d, respectively, following addition of the rhamnolipid. However, addition of an electron donor, electron acceptor, surfactant, and Fe powder did not always increase the degradation of different kinds of OPEs, which was closely related to the structure of the OPEs. No treatment increased the removal of alkyl OPEs due to their low anaerobic degradability. Tween 80, a non-ionic surfactant, inhibited anaerobic degradation to some degree for all OPEs. Under aerobic conditions, alkyl OPEs were more easily degraded, chlorinated OPEs needed a long adaptation period to degrade and finally attain a 90% removal rate, while the rates of degradation of triphenyl ester OPEs were significantly affected by the concentration of sludge. Higher sludge concentrations help microorganisms to adapt and remove OPEs. This study provides new insights into methods for eliminating emerging pollutants using activated sludge cultured with kitchen garbage biomass and agricultural residues.

Denitrification kinetics in an activated sludge system

1995 ◽  
Vol 32 (9-10) ◽  
pp. 323-330
Author(s):  
M. Roš
Keyword(s):  
Activated Sludge ◽  
Closed System ◽  
Open Systems ◽  
Aeration Tank ◽  
Activated Sludge System ◽  
Denitrification Kinetics ◽  
Closed Systems ◽  
Nitrate And Nitrite ◽  
Sludge Concentration

For all water bodies especially for sea, lakes, and ground waters it is very important that nutrient pollution is the least possible (minimal). From municipal and industrial waste waters where considerable amount of nutrients is expected it is possible to remove nutrients with biological treatment. The first step is usually aerobic activated sludge treatment and the second step is combined anaerobic-anoxic-aerobic step in different combinations. A very effective process for nitrogen removal is anoxic activated sludge system. It is very important that in the first aerobic step complete nitrification is achieved. In our laboratory denitrification kinetics was studied. The objective of this study was determination of denitrification velocity and attendance of different parallel phenomena such as nitrite, disappearance of nitrate and nitrite, sulphide formation, etc. Denitrification process was studied in two systems, in closed system (such as in closed reactors for denitrification) and in open systems (such as in open denitrification tanks). We found out that denitrification rate in closed systems was from about 8 to 52 mg/l.h and was dependent on activated sludge type, sludge concentration, and temperature of the system. In open system (such as in an anoxic aeration tank) the rate of denitrification was lower than in closed system; it was from 4 to 15 mg/l.h dependent on activated sludge type, sludge concentration, and temperature of the system. Experiments were carried out in the range of temperature from 20° to 30°C.

Experiment Study on Microwave Strengthened Fenton Process Oxidation of Organophosphorus Pesticide Wastewater

2012 ◽  
Vol 260-261 ◽  
pp. 792-795
Author(s):  
Ya Feng Li ◽  
Jing Xin Wang ◽  
Yan Zhang
Keyword(s):  
Synergistic Effect ◽  
Microwave Radiation ◽  
Microwave Power ◽  
Removal Rate ◽  
Organophosphorus Pesticide ◽  
Good Effect ◽  
Fenton Process ◽  
Experiment Study ◽  
Cod Removal Rate ◽  
Radiation Time

Microwave strengthened Fenton process oxidation of organophosphorus pesticide wastewater was studied by microwave chemical technology. With the synergistic effect of microwave and Fenton, pesticide wastewater was treated by varying dosage of pH, n[FeSO4•7H2O]/n[H2O2], microwave power and microwave radiation time. Microwave strengthened Fenton process oxidation of organophosphorus pesticide wastewater could achieve good effect and the COD removal rate can be up to 82%.

scholarly journals Concentration of active sludge in the aeration reactors

2018 ◽  
Vol 178 ◽  
pp. 09022
Author(s):  
Nina Zaletova ◽  
Nadezhda Morozova
Keyword(s):  
Enzyme Activity ◽  
Activated Sludge ◽  
Dehydrogenase Activity ◽  
Tap Water ◽  
Experimental Studies ◽  
Aeration Tank ◽  
Active Sludge ◽  
Wastewater Treatment Process ◽  
First Case ◽  
Actual Substrate

The purpose of the paper was to study the dehydrogenase activity (DHA) of activated sludge in aeration tank. The article describes a change in enzyme activity, (dehydrogenase activity of sludge-DHA) of activated sludge while various time of aeration as well as various dose in sludge of aeration tank. Assessment changes enzyme activity were done on two indicators - on DHAor. (original dehydrogenase activity of sludge) and DHAH2O (dehydrogenase sludge activity with tap water). In the first case - DHA with the actual substrate, in the second case - DHA with poorly concentrated substrate. The work was performed on a pilot installation consisting of four models of aeration tanks blocked with sedimentation tanks, on a real city waste water. Working doses of sludge in biological wastewater treatment process was ranged from 2 to 6 g/l, time of aeration in aeration tanks changed from 3.5. up to 0.8 hours. Experimental studies have shown that regardless of the size of working sludge dose in aeration tank character of changes DHA or and DHAH2O is identical.

scholarly journals TREATING PALM OIL MILL EFFLUENT BY ACTIVATED SLUDGE PROCESS USING SUBMERGED MECHANICAL AERATOR/AGITATOR REPLACING SURFACE AERATOR

2019 ◽  
Vol 81 (3) ◽  
Author(s):  
Yahaya Hawari ◽  
Wira Jazair Yahya ◽  
Ikuma Sonda ◽  
Hirotaka Kawashima ◽  
Zahari Mohamad ◽  
...  
Keyword(s):  
Water Quality ◽  
Activated Sludge ◽  
Palm Oil ◽  
Removal Rate ◽  
Palm Oil Mill Effluent ◽  
Aeration Tank ◽  
Water Quality Criteria ◽  
Activated Sludge Process ◽  
Activated State ◽  
Palm Oil Mill

Activated sludge process (ASP) is gaining recognition as a process technique for the control of biological oxygen demand (BOD) in palm oil mill effluent (POME). Surface aerators or diffusing plates are often used in aeration tanks serving as core of the ASP. For consistent improvement in water quality within the aeration tank utilising the ASP and in particular, mitigating its BOD effluent stream, this study replaced the surface aerator with submerged mechanical aerator/agitator incorporating separate “agitation function” and “agitation diffusing function” intended for use in aeration tank of polishing plant that contains surface aerators. In order to confirm the activated state of the sludge in the aeration tanks, sludge was observed by microscopy (magnification 600 ´ or lower). The water analysis, POME, BOD, ammonium, and total nitrogen were analsyed. As a result of the study, improvement in water quality criteria including the agitation state in the aeration tank, mixed liquid dissolved oxygen, and BOD were observed. The BOD has improved from 34.7% to 93.1% at a maximum removal rate.

Study on the Advanced Treatment of Pulp and Paper Wastewater by Fenton Oxidation and its Comparison with Ozone Oxidation

2013 ◽  
Vol 726-731 ◽  
pp. 1744-1750 ◽  
Author(s):  
Li Jun Huang ◽  
Li Ying Song ◽  
Hong You Wan ◽  
Ke Zeng
Keyword(s):  
Reaction Time ◽  
Treatment Effect ◽  
Removal Rate ◽  
Pulp And Paper ◽  
Cod Removal ◽  
Fenton Oxidation ◽  
Ozone Oxidation ◽  
Continuous Increase ◽  
Paper Wastewater ◽  
Cod Removal Rate

The treatment on the secondary biochemical effluent of pulp and paper wastewater by Fenton oxidation was studied and the influence of H2O2dosage, Fe2+dosage, pH and reaction time on the treatment effect was investigated by the orthogonal test and single-factor test. The treatment effect was eminent when the H2O2dosage was 3.75mmol/L, Fe2+dosage was 3.20mmol/L, pH was 4.00 and the reaction time was 80.00min. The removal rate of UV254and chromaticity significantly increased as H2O2dosage was 1.88 ~ 3.75mmol /L, but the COD removal rate declined as H2O2dosage was more than 2.81mmol/L; each removal rate increased and then decreased slightly with the increase of Fe2+dosage, each removal rate dropped obviously as pH was more than 5.00; within 80.00min, the removal rate increased significantly, it changed little with the continuous increase of reaction time. Under the optimal conditions, the COD removal with Fenton oxidation was more effective and its removal rate could achieve 88.33%, it was advantageous compared with ozone oxidation; but the elimination effect of UV254and chromaticity to pulp and paper wastewater with ozone oxidation was better, the two removal rate achieved 83.70% and 92.00% in a short time, respectively. Although it could reach such a removal effect by Fenton oxidation, it did not have the superiority in reaction time.

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