scholarly journals Comparison of Azithromycin Removal from Water Using UV Radiation, Fe (VI) Oxidation Process and ZnO Nanoparticles

2020 ◽  
Vol 17 (5) ◽  
pp. 1758
Author(s):  
Amirreza Talaiekhozani ◽  
Sahar Joudaki ◽  
Farhad Banisharif ◽  
Zeinab Eskandari ◽  
Jinwoo Cho ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Zno Nanoparticles ◽  
Retention Time ◽  
Langmuir Isotherm ◽  
Hydraulic Retention Time ◽  
Oxidation Process ◽  
Radiation Power ◽  
Biological Processes ◽  
Optimal Conditions ◽  
Initial Concentration

Antibiotics are resistant to biodegradation, and their removal by biological processes is difficult. The purpose of this study was to investigate the removal of azithromycin from water using ultraviolet radiation (UV), Fe (VI) oxidation process and ZnO nanoparticles. The effect of different parameters such as pH, temperature, hydraulic retention time (HRT), the concentration of Fe (VI) and ZnO nanoparticles and UV intensity on the removal of azithromycin from water was investigated. The optimal conditions for the removal of azithromycin were a pH of 2, a temperature of 25 °C, a HRT of 15 min, and a ratio of ZnO nanoparticles to the initial concentration of azithromycin (A/P) of 0.00009 which was fitted by Langmuir isotherm. In addition, the optimal conditions for the removal of azithromycin using UV radiation were a pH of 7, a temperature of 65 °C, a HRT of 60 min, and UV radiation power of 163 mW/cm2. For the Fe (VI) oxidation process, the optimal conditions were a pH of 2, a temperature of 50 °C and a HRT of 20 min. Also, the optimal ratio of Fe (VI) to the initial concentration of antibiotic was between 0.011 and 0.012. The results of this study showed that the Fe (VI) oxidation process, UV radiation, and ZnO nanoparticles were efficient methods for the removal of azithromycin from water.

scholarly journals UV-LED Combined with Small Bioreactor Platform (SBP) for Degradation of 17α-Ethynylestradiol (EE2) at Very Short Hydraulic Retention Time

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5960
Author(s):  
Oran Fradkin ◽  
Hadas Mamane ◽  
Aviv Kaplan ◽  
Ofir Menashe ◽  
Eyal Kurzbaum ◽  
...  
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Light Emission ◽  
Degradation Products ◽  
Secondary Effluent ◽  
Direct Photolysis ◽  
Indirect Photolysis ◽  
Uv Led

Degradation of 17α-ethynylestradiol (EE2) and estrogenicity were examined in a novel oxidative bioreactor (OBR) that combines small bioreactor platform (SBP) capsules and UV-LED (ultraviolet light emission diode) simultaneously, using enriched water and secondary effluent. Preliminary experiments examined three UV-LED wavelengths—267, 279, and 286 nm, with (indirect photolysis) and without (direct photolysis) H2O2. The major degradation wavelength for both direct and indirect photolysis was 279 nm, while the major removal gap for direct vs. indirect degradation was at 267 nm. Reduction of EE2 was observed together with reduction of estrogenicity and mineralization, indicating that the EE2 degradation products are not estrogens. Furthermore, slight mineralization occurred with direct photolysis and more significant mineralization with the indirect process. The physical–biological OBR process showed major improvement over other processes studied here, at a very short hydraulic retention time. The OBR can feasibly replace the advanced oxidation process of UV-LED radiation with catalyst in secondary sedimentation tanks with respect to reduction ratio, and with no residual H2O2. Further research into this OBR system is warranted, not only for EE2 degradation, but also to determine its capabilities for degrading mixtures of pharmaceuticals and pesticides, both of which have a significant impact on the environment and public health.

Study on Cu2+ Removal from Water via an Cation Exchange Membrane

2012 ◽  
Vol 253-255 ◽  
pp. 954-959
Author(s):  
De Hua Xie
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Potassium Ions ◽  
Inlet Concentration ◽  
Experimental Conditions ◽  
External Voltage ◽  
Initial Concentration ◽  
Exchange Membrane

The removal of Cu2+ in water via an ion-exchange membrane under no external voltage condition was studied in the research, and effects such as Cu2+ concentration, concentration of compensation potassium ions, water stirring speed, temperature and hydraulic retention time (HRT) on the removal efficiency of Cu2+ were also investigated. The results showed that when the initial concentration of bivalent ion Cu2+ was 0.0787mmol/L （5mg/L）, under the experimental conditions of the water temperature at 25 °C , the HRT was 6h, the hydraulic mixing speed was 600±25rpm, and the concentration of the compensation ion K+ was 10 times as that of Cu2+, and the removal efficiency of Cu2+ could be achieved 85%. In addition, using the same equipments, when the inlet concentration of Cu2+ increased to 0.787mmol/L (50mg/L), the removal efficiency would be decreased to 76%; while the ratio of concentration of compensation potassium ions to that of inlet Cu2+ is larger than 20, the removal efficiency would not change significantly as the ratio continued increasing; the removal efficiency would be decreased to 60% when lowering the stirring speed to 300±25rpm; the removal efficiency would be decreased to 68% when lowering the temperature to 15+1 °C; the removal rate was no significant change when the hydraulic retention time (HRT) from 6h to 12h.

Pretreatment of Seawater by PAC/PAM Coagulation-Photocatalytic Oxidation Process

2013 ◽  
Vol 779-780 ◽  
pp. 1518-1521
Author(s):  
Yu Lian Quan ◽  
Bi Qing Shi ◽  
Li Jing Yang ◽  
Ren Zhi Zhang
Keyword(s):  
Synergistic Effect ◽  
Reverse Osmosis ◽  
Uv Radiation ◽  
Photocatalytic Oxidation ◽  
Oxidation Process ◽  
Optimal Conditions ◽  
Effluent Water ◽  
Radiation Time ◽  
Simulated Seawater ◽  
Polyaluminium Chloride

Coagulation-photocatalytic oxidation process was used for pretreatment of simulated seawater, which had moderate turbidity and more organics. The optimal conditions of PAC/PAM coagulation and TiO2 photocatalytic oxidation were investigated by simple variable method, coagulation and photocatalytic oxidation were combinated under optimal conditions finally. Results showed that when the dosage of polyacrylamide (PAM) and polyaluminium chloride (PAC) was 20mg/L and 0.5 mg/L respectively, the pH of simulated seawater was 8.0, the amount of TiO2 photocatalyst was 1.8g/L and UV radiation time was 1h, the removal ratio of the turbidity and CODMn in simulated seawater was 97.5% and 72% respectively. Synergistic effect between coagulation and photocatalytic oxidation eventually made turbidity and organics in the effluent water meet the requirements of reverse osmosis system.

Aerobic biological treatment of thermophilically digested sludge

2011 ◽  
Vol 63 (10) ◽  
pp. 2340-2345 ◽  
Author(s):  
M. V. Kevbrina ◽  
Y. A. Nikolaev ◽  
D. A. Danilovich ◽  
A. Ya. Vanyushina
Keyword(s):  
Retention Time ◽  
Biological Treatment ◽  
Hydraulic Retention Time ◽  
Treatment Plant ◽  
Ammonium Nitrogen ◽  
Wastewater Sludge ◽  
Optimal Conditions ◽  
Nitrogen And Phosphorus ◽  
Digested Sludge ◽  
Sludge Treatment

Aerobic biological treatment of digested sludge was studied in a continuously operated laboratory set-up. An aerated reactor was filled with thermophilically digested sludge from the Moscow wastewater treatment plant and inoculated with special activated sludge. It was then operated at the chemostat mode at different flow rates. Processes of nitrification and denitrification, as well as dephosphatation, occurred simultaneously during biological aerobic treatment of thermophilically digested sludge. Under optimal conditions, organic matter degradation was 9.6%, the concentrations of ammonium nitrogen and phosphate decreased by 89 and 83%, respectively, while COD decreased by 12%. Dewaterability of digested sludge improved significantly. The processes were found to depend on hydraulic retention time, oxygen regime, and temperature. The optimal conditions were as follows: hydraulic retention time 3–4 days, temperature 30–35 °C, dissolved oxygen levels 0.2–0.5 mg/L at continuous aeration or 0.7–1 mg/L at intermittent aeration. Based on these findings, we propose a new combined technology of wastewater sludge treatment. The technology combines two stages: anaerobic digestion followed by aerobic biological treatment of digested sludge. The proposed technology makes it possible to degrade the sludge with conversion of ∼45% volatile suspended solids to biogas, to improve nitrogen and phosphorus removal in reject water from sludge treatment units, and to achieve removal of malodorous substances after 8–9 days of anaerobic–aerobic sludge treatment.

High-rate pond for treatment of piggery wastes

2000 ◽  
Vol 42 (10-11) ◽  
pp. 357-362 ◽  
Author(s):  
R. H. Costa ◽  
W. Medri ◽  
C. C. Perdomo
Keyword(s):  
Nitrogen Removal ◽  
Retention Time ◽  
Phosphorus Removal ◽  
Flow Model ◽  
Hydraulic Retention Time ◽  
Plug Flow ◽  
High Rate ◽  
Initial Concentration ◽  
Ph Values ◽  
Total Nitrogen Removal

This work deals with studies on high-rate ponds, a batch working system that is followed by a filter pond where Chinese carp were introduced for piggery wastes treatment. COD removal values for the high-rate pond were in the order of 95% in the summer and 70% in the winter for an initial concentration of 2000 mg/L. Total nitrogen removal values ranged between 90% and 60%, respectively, in summer and winter periods for an initial concentration of 600 mg/L. Seasonal variations, which are mainly observed under differences of temperature, were shown to be not relevant for total phosphorus removal, a process that appears to depend mainly on increases of pH values over 8.5. An hydraulic retention time ranging between 15 to 20 days was found to be best for pond functioning. The plug flow model fits well to the pond's physical characteristics. The filter pond was shown to be a great potential process for removal of algae produced in the high-rate pond.

scholarly journals The Use of Electrocoagulation to Remove Fluoride, Nitrates and Phosphorous from Water

2021 ◽  
Vol 877 (1) ◽  
pp. 012021
Author(s):  
Rusul K Abdulkhadher ◽  
Ali j Jaeel
Keyword(s):  
Retention Time ◽  
Applied Voltage ◽  
Industrial Waste ◽  
Hydraulic Retention Time ◽  
Active Area ◽  
Flow Angle ◽  
Initial Concentration ◽  
Aluminum Electrodes

Abstract In recent times, the concentrations of fluoride, nitrates and phosphates in the water have increased as a result of a decrease in the quantities of water and an increase in industrial waste dumped into the rivers. In the current study, a method of electrocoagulation was depended on to treat water contaminated with fluoride, nitrates, and phosphates, using aluminum electrodes as anode and cathode electrodes. According to the obtained results, it can be noticed that the best fluoride, nitrates, and phosphates removal were 99%, 99%, 100%, respectively. It was obtained with a Hydraulic retention time HRT = 3 hours, an applied voltage = 40 volts, a gap between the used electrodes=2 cm, the anode’s active area= 792 cm2, and the flow angle= zero. By using an initial concentration (5 mg F/l, with pH= 4) for fluoride, (75 mg NO3/l, with pH= 6) for nitrates, and (0.5 mg PO4 / l, with pH=9) for phosphates.

Effect of Hydraulic Retention Time on Pollutant Removal Performance of Biological Contact Oxidation Process Treating Hospital Wastewater

2014 ◽  
Vol 507 ◽  
pp. 725-729
Author(s):  
Bo Yu ◽  
Ying Zhou ◽  
Zheng Wen Huang ◽  
Li Chen
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Oxidation Process ◽  
Removal Rate ◽  
Pollutant Removal ◽  
Hospital Wastewater ◽  
Additional Processing ◽  
Contact Oxidation ◽  
Biological Contact Oxidation ◽  
Processing Steps

A study on hospital wastewater treatment was carried out using biological contact oxidation process. The effect of hydraulic retention time (HRT) on BOD5, CODCr and SS removal was investigated. The results showed that the removal rate of BOD5, and CODCr was ascending with the increase of HRT using the contrast test of five different HRTs. When the HRT was more than 4h, the effluent BOD5, CODCr could meet the discharge standard (GB18466-2005). In considering of raising the biodegradability of effluent, 4h was recommended in this study. However, the whole trend of SS variation of system was not obvious with the increase of HRT, and the effluent SS could not meet the discharge standard (20mg/L). Thus, the additional processing steps to remove SS would be necessary.

scholarly journals Comparing the ZnO/Fe(VI), UV/ZnO and UV/Fe(VI) processes for removal of Reactive Blue 203 from aqueous solution

2019 ◽  
Vol 6 (1) ◽  
pp. 27-39 ◽  
Author(s):  
Amirreza Talaiekhozani ◽  
Farhad Banisharif ◽  
Maryam Bazrafshan ◽  
Zeinab Eskandari ◽  
Abbas Heydari Chaleshtari ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Uv Radiation ◽  
Zno Nanoparticles ◽  
Oxidation Process ◽  
Hybrid Methods ◽  
Combined Processes ◽  
Optimum Conditions ◽  
Study Results ◽  
Suitable Treatment ◽  
Combined Methods

Background: Wastewater contaminated with dyes such as Reactive Blue 203 can produce a lot of health problems if it is released into the environment without a suitable treatment. Although there are several studies on dye removal from wastewater, removal of Reactive Blue 203 has not been investigated by hybrid methods. Therefore, the aim of this study was to investigate the removal of Reactive Blue 203 from aqueous solution, using combined processes of zinc oxide (ZnO) nanoparticles, Fe(VI) oxidation process, and UV radiation. Methods: The removal of dye from aqueous solution using ZnO nanoparticles, Fe(VI) oxidation process, and UV radiation was individually evaluated. Then, the results of combined methods were compared. Hydraulic retention time (HRT), pH, and temperature were the most important factors which were investigated in this study. Results: ZnO nanoparticles, Fe(VI) oxidation process, and UV radiation were able to remove 97%, 71%, and 47% of the dye in the optimal conditions, respectively. Also, the removal of dye using combination of Fe(VI) oxidation process/UV radiation, ZnO nanoparticles/Fe(VI) oxidation process, and ZnO nanoparticles/UV radiation under optimum conditions was 100%. It seems that the combined methods were significantly more effective than the methods alone for removal of dye from water. Conclusion: UV radiation alone is a simple and efficient method for removal of Reactive Blue 203 from water. Removal of Reactive Blue 203 using Fe(VI) oxidation process can be completed in a fraction of second, therefore, it can be categorized as a rapid reaction.

The nitrogen removal potential of predenitrification systems in sensitive coastal areas

1995 ◽  
Vol 32 (7) ◽  
pp. 135-142
Author(s):  
E. Görgün ◽  
N. Artan ◽  
D. Orhon ◽  
R. Tasli
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Retention Time ◽  
Treatment Process ◽  
Hydraulic Retention Time ◽  
Domestic Sewage ◽  
Coastal Areas ◽  
Careful Evaluation ◽  
Denitrification Kinetics

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.

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