A comparative study on the performance of photo/sono/peroxone processes for the removal and mineralization of reactive dye red 198 from aquatic environments

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hasan Safari ◽  
Mojgan Zaeimdar ◽  
Morteza Kashefi ALasl ◽  
Yousef Dadban Shahamat ◽  
Reza Marandi
Keyword(s):  
Removal Efficiency ◽  
High Performance ◽  
Advanced Oxidation Process ◽  
Complex Structure ◽  
Reactive Dye ◽  
Hybrid Process ◽  
Effective Parameters ◽  
Treated Effluent ◽  
Reactive Red 198 ◽  
Colored Wastewater

Abstract Colored wastewater is the most important problem of textile manufacturing factories, because it contains pollutants with complex structure and toxic, carcinogenic, and mutagenic properties which are non-biodegradable and sustainable in the environment. Reactive Red 198 (RR198) is one of the types of azo dyes which are widely used in the textile industries. Therefore, in this study, the rate of degradation and mineralization of RR198 by UV/US/H2O2/O3 hybrid process was investigated. Influencing factors including: initial dye concentration (100, 200, 300, 400, 500 mg/L), contact time (12.5, 30, 47.5, 65, 82.5 min), pH (3, 5, 7, 9, 11), UV (125-W), H2O2 (10, 20, 30, 40, 50 mg/L), US (160 KHz) and O3 (33 mg/(L·min)) on the removal and mineralization efficiency of RR198 were investigated. Optimization and modeling of the process was done by CCD method. Based on the results of ANOVA analysis, most effective parameters on the RR198 removal efficiency were ozone, US, UV, time, initial dye concentration, pH, and H2O2, respectively, with an impact percentage of 96.86 and less than 1% for ozone and the rest parameters, respectively. Highest removal efficiency of RR198 was obtained by UV/US/H2O2/O3 hybrid process. Optimal conditions for dye removal including: initial dye concentration of 200 mg/L, reaction time of 34 min, H2O2 concentration of 27 mg/L and pH of seven were determined in the presence of ozone gas, UV, and US waves. In these conditions, the removal efficiency of RR198 and TOC were estimated to be 100 and 40.5, respectively. UV/US/H2O2/O3 hybrid process as an advanced oxidation process (AOP) with advantages such as high performance and speed, no sludge production and toxic residues in the treated effluent containing hard biodegradable compounds such as RR198 from aqueous solutions, so can be recommended and used.

scholarly journals HOGLA LEAF AS A POTENTIAL BIO-ADSORBENT FOR THE TREATMENT OF REACTIVE DYES IN TEXTILE EFFLUENTS

2020 ◽  
Vol 4 (12) ◽  
pp. 1-7
Author(s):  
Abdul Khalque ◽  
Shaikh Ahammed ◽  
Saquib Khan ◽  
Rabiul Awual ◽  
K.Ayaz Rabbani ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Contact Time ◽  
Reactive Dyes ◽  
Textile Wastewater ◽  
Complete Removal ◽  
Reactive Dye ◽  
Textile Effluents ◽  
Typha Angustata ◽  
Colored Wastewater ◽  
Wastewater Samples

A new bio-adsorbent to remove reactive dyes from textile effluent was investigated in the present study. The adsorbent was the leaves of locally available hogla plant (Typha angustata). Initially, sunfix yellow, a reactive dye widely used in textile effluents, was used to check the removal efficiency in terms of contact time, pH of dye solution and adsorbent dosage. Complete removal (100%) of dye was achieved at adsorbent/dye ratio of 2300:1 at pH 10 with 180 minutes contact time. The adsorbent was then applied to deep colored, raw textile wastewater samples and it was found that 2.3 g of adsorbent was able to convert 100 mL of deep colored wastewater to transparent water at pH 10. Additionally, treatment by the adsorbent resulted in significant decreases in pH, BOD, COD, TS, TDS and TSS of wastewater, while improving the DO level.

scholarly journals Post-treatment of tannery wastewater using pilot scale horizontal subsurface flow constructed wetlands (polishing)

2017 ◽  
Vol 77 (4) ◽  
pp. 988-998 ◽  
Author(s):  
Tadesse Alemu ◽  
Andualem Mekonnen ◽  
Seyoum Leta
Keyword(s):  
Removal Efficiency ◽  
Batch Reactor ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Surface Flow ◽  
Tannery Wastewater ◽  
Treated Effluent ◽  
Horizontal Subsurface Flow ◽  
Pollutants Removal

Abstract In the present study, a pilot scale horizontal subsurface flow constructed wetland (CW) system planted with Phragmites karka; longitudinal profile was studied. The wetland was fed with tannery wastewater, pretreated in a two-stage anaerobic digester followed by a sequence batch reactor. Samples from each CW were taken and analyzed using standard methods. The removal efficiency of the CW system in terms of biological oxygen demand (BOD), chemical oxygen demand (COD), Cr and total coliforms were 91.3%, 90%, 97.3% and 99%, respectively. The removal efficiency for TN, NO3− and NH4+-N were 77.7%, 66.3% and 67.7%, respectively. Similarly, the removal efficiency of SO42−, S2− and total suspended solids (TSS) were 71.8%, 88.7% and 81.2%, respectively. The concentration of COD, BOD, TN, NO3−N, NH4+-N, SO42 and S2− in the final treated effluent were 113.2 ± 52, 56 ± 18, 49.3 ± 13, 22.75 ± 20, 17.1 ± 6.75, 88 ± 120 and 0.4 ± 0.44 mg/L, respectively. Pollutants removal was decreased in the first 12 m and increased along the CW cells. P. karka development in the first cell of CW was poor, small in size and experiencing chlorosis, but clogging was higher in this area due to high organic matter settling, causing a partial surface flow. The performance of the pilot CW as a tertiary treatment showed that the effluent meets the permissible discharge standards.

Synthesis and Application of Zn‑BTC/GO Nanocomposites as Highly Efficient Photocatalysts in the Dye Degradation

2021 ◽  
Vol 11 (1) ◽  
pp. 67-73
Author(s):  
Manh Nguyen Ba ◽  
Trang Pham Thi Thu ◽  
Hoa Tran Thi ◽  
Giang Le Ha
Keyword(s):  
Removal Efficiency ◽  
Dye Degradation ◽  
High Surface ◽  
High Surface Area ◽  
Reactive Dye ◽  
High Photocatalytic Activity ◽  
Microwave Method ◽  
Sem Image ◽  
High Initial Concentration ◽  
Reactive Red 195

Nanocomposite Zn-BTC/GO (BTC: benzene-1,3,5-tricarboxylic, GO: graphene oxide) was successfully synthesized by hydrothermal treatment with a microwave method. Samples were characterized by XRD, FTIR, EDS-mapping, BET, SEM, UV-vis DRS and XPS. SEM-image result showed nano Zn-BTC/GO particles size of 50-80 nm. Nanocomposite Zn-BTC/GO showed the a high surface area (1303 m2/g) and pore volume (1.08 cm3/g). The Zn-BTC/GO nanocomposite were tested for the photocatalytic degradation of reactive dye (Reactive Red 195) in an aqueous solution. The Zn-BTC/GO composites exhibited high photocatalytic activity. Thus, at the pH of 6.5 and the high initial concentration of 30 mg RR-195/L, removal efficiency reached the value of 96.16% after 60 min reaction. Moreover, nano Zn-BTC also showed high RR-195 removal efficiency after 3 catalytic regeneration. This contributes to sustainable development and green chemistry.

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.

Combined organic carbon and complete nitrogen removal using anaerobic and aerobic upflow filters

1994 ◽  
Vol 30 (12) ◽  
pp. 297-306 ◽  
Author(s):  
Joseph Akunna ◽  
Claude Bizeau ◽  
René Moletta ◽  
Nicolas Bernet ◽  
Alain Héduit
Keyword(s):  
Organic Carbon ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Nitrogen Loss ◽  
Ammonia Nitrogen ◽  
Cod Removal ◽  
Cod Removal Efficiency ◽  
Treated Effluent ◽  
Treated Effluents ◽  
Aerobic And Anaerobic

Two laboratory upflow aerobic and anaerobic filters fed with synthetic wastewaters were used to study firstly the effects of aeration rate on the nitrification of anaerobically pre-treated effluents and secondly the effects of recycle-to-influent ratios on methane production rate, denitrification and nitrification performances of a combined aerobic and anaerobic wastewater treatment process. Nitrification of anaerobically pre-treated effluent was accompanied by aerobic post-treatment for residual COD removal. A comparison of nitrification performances using autotrophic medium and anaerobically pre-treated effluents (containing 1203 mg COD 1−1) with the same ammonia nitrogen concentration of about 300 mg NH4-N 1−1 showed that 3% of added ammonia nitrogen was assimilated by autotrophic nitrifiers during nitrification of the autotrophic medium while up to 30% was assimilated by both nitrifiers and heterotrophs during organic carbon removal and nitrification of anaerobically pre-treated effluent. Furthermore, it was suspected that significant nitrogen loss through denitrification occured in the aerobic filter especially at low aeration rates. In the study of the combined aerobic-anaerobic system, maximum ammonia nitrogen removal of 70% through denitrification was obtained at recycle-to-influent ratios of 4 and 5. COD removal efficiency in the anaerobic filter decreased from 77 to 60% for recycle-to-influent ratios of zero to 5. Overall COD removal efficiency of the entire system was constant at about 99% due to heterotrophic COD removal in the aerobic filter.

scholarly journals Degradation of reactive red 198 from aqueous solutions by advanced oxidation process: O3, O3/H2O2, and persulfate

2016 ◽  
Vol 5 (1) ◽  
pp. 26 ◽  
Author(s):  
Bijan Bina ◽  
MohammadAmin Karami ◽  
MohammadMehdi Amin ◽  
Heshmatollah Nourmoradi ◽  
Mohsen Sadani ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Advanced Oxidation ◽  
Reactive Red 198

scholarly journals Synthesis, characteristics, and photocatalytic activity of zinc oxide nanoparticles stabilized on the stone surface for degradation of metronidazole from aqueous solution

2021 ◽  
Vol 8 (1) ◽  
pp. 55-63
Author(s):  
Amir Nasser Alibeigi ◽  
Neda Javid ◽  
Majid Amiri Gharaghani ◽  
Zhila Honarmandrad ◽  
Fatemeh Parsaie
Keyword(s):  
Zinc Oxide ◽  
Removal Efficiency ◽  
Zno Nanoparticles ◽  
Advanced Oxidation Process ◽  
Degradation Kinetics ◽  
Hexagonal Wurtzite Structure ◽  
Sem Analysis ◽  
Thermal Method ◽  
Average Crystalline Size ◽  
Stone Surface

Background: The presence of antibiotics such as metronidazole in wastewater even at low concentrations requires searching for a suitable process such as advanced oxidation process (AOP) to reduce the level of pollutants to a standard level in water. Methods: In this study, zinc oxide (ZnO) nanoparticles were synthesized by thermal method using zinc sulfate (ZnSO4 ) as a precursor, then, stabilized on stone and was used as a catalyst, in order to degrade metronidazole by photocalytic process. Effective factors on the removal efficiency of metronidazole including the initial metronidazole concentration, contact time, pH, and 0.9 gL-1 ZnO stabilized on the stone surface were investigated. Results: The X-ray diffraction (XRD) studies showed that the synthesized nanomaterials have hexagonal Wurtzite structure. Also, scanning electron microscopy (SEM) analysis revealed that the average crystalline size of the synthesized ZnO particles was in the range of 1.9-3.2 nm. The spectra represented a sharp absorption edge at 390 nm for ZnO nanoparticles corresponding to band gap of 3.168 eV. The BET-BJH specific surface area of the synthesized ZnO nanoparticles was 25.504 m2 /g. The EDS spectrum of ZnO nanoparticles showed four peaks, which were identified as Zn and O. The maximum removal efficiency was 98.36% for the synthetic solution under a specific condition (pH = 11, reaction time = 90 minutes, ZnO concentration = 0.9 gL-1, and the initial concentration of metronidazole = 10 mgL-1). The photocatalytic degradation was found to follow pseudo-first-order degradation kinetics. Conclusion: Therefore, the ZnO nanoparticles synthesized by thermal decomposition are suitable and effective photocatalytic materials for degradation of pharmaceutical contaminants.

scholarly journals Optimization and Modeling of Microcystin-LR Degradation by TiO2 Photocatalyst Using Response Surface Methodology

2020 ◽  
Author(s):  
Negar Jafari ◽  
Afshin Ebrahimi ◽  
Karim Ebrahimpour ◽  
Ali Abdolahnejad
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Contact Time ◽  
High Performance ◽  
Operating Variables ◽  
Effective Removal ◽  
Positive Effect ◽  
Harmful Effects ◽  
Maximum Removal

Introduction: Microcystin-leucine arginine (MC-LR) is a toxin with harmful effects on the liver, kidney, heart, and gastrointestinal tract. So, effective removal of MC-LR from water resources is of great importance. The aim of this study was to remove microcystin-LR (MC-LR) from aqueous solution by Titanium Dioxide (TiO2). Materials and Methods: In the present study, TiO2, as a semiconductor, was used for photodegradation of MC-LR under ultraviolet light (UV). The Response Surface Methodology was applied to investigate the effects of operating variables such as pH (A), contact time (B), and catalyst dose (B) on the removal of MC-LR. The MC-LR concentration was measured by high-performance liquid chromatography (HPLC). Results: The results showed that single variables such as A, B, and C had significant effects on MC-LR removal (pvalue < 0.05). In other words, increase of the contact time and catalyst dose had a positive effect on enhancing the removal efficiency of MC-LR, but the effect of pH was negative. The analysis of variance showed that BC, A2, and C2 variables had a significant effect on the MC-LR removal (pvalue < 0.05). Finally, the maximum removal efficiency of MC-LR was 95.1%, which occurred at pH = 5, contact time = 30 minutes, and catalyst dose = 1 g/l. Conclusion: According to the findings, TiO2, as a photocatalyst, had an appropriate effect on degradation of the MC-LR.

Mechanical Reliability of Silicon Microstructures

2021 ◽  
Author(s):  
Toshiyuki Tsuchiya
Keyword(s):  
High Performance ◽  
Measurement Data ◽  
Design Guidelines ◽  
Fatigue Properties ◽  
Mechanical Reliability ◽  
Effective Parameters ◽  
Micro Electro Mechanical Systems ◽  
Device Reliability ◽  
Silicon Microstructures ◽  
Silicon Based

Abstract In this article, an overview of the mechanical reliability of silicon microstructures for micro-electro-mechanical systems (MEMS) is given to clarify what we now know and what we still have to know about silicon as a high-performance mechanical material on the microscale. Focusing on the strength and fatigue properties of silicon, attempts to understand the reliability of silicon and to predict the device reliability of silicon-based microstructures are introduced. The effective parameters on the strength and the mechanism of fatigue failure are discussed with examples of measurement data to show the design guidelines for highly reliable silicon microstructures and devices.

scholarly journals Effects of salinity on the treatment of synthetic petroleum-industry wastewater in pilot vertical flow constructed wetlands under simulated hot arid climatic conditions

2020 ◽  
Vol 28 (2) ◽  
pp. 2172-2181
Author(s):  
Thomas V. Wagner ◽  
Fatma Al-Manji ◽  
Jie Xue ◽  
Koen Wetser ◽  
Vinnie de Wilde ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Removal Efficiency ◽  
Constructed Wetlands ◽  
Membrane Fouling ◽  
Plant Defence ◽  
Petroleum Industry ◽  
Vertical Flow ◽  
Treated Effluent ◽  
The Impact ◽  
Industry Wastewater

AbstractPetroleum-industry wastewater (PI-WW) is a potential source of water that can be reused in areas suffering from water stress. This water contains various fractions that need to be removed before reuse, such as light hydrocarbons, heavy metals and conditioning chemicals. Constructed wetlands (CWs) can remove these fractions, but the range of PI-WW salinities that can be treated in CWs and the influence of an increasing salinity on the CW removal efficiency for abovementioned fractions is unknown. Therefore, the impact of an increasing salinity on the removal of conditioning chemicals benzotriazole, aromatic hydrocarbon benzoic acid, and heavy metal zinc in lab-scale unplanted and Phragmites australis and Typha latifolia planted vertical-flow CWs was tested in the present study. P. australis was less sensitive than T. latifolia to increasing salinities and survived with a NaCl concentration of 12 g/L. The decay of T. latifolia was accompanied by a decrease in the removal efficiency for benzotriazole and benzoic acid, indicating that living vegetation enhanced the removal of these chemicals. Increased salinities resulted in the leaching of zinc from the planted CWs, probably as a result of active plant defence mechanisms against salt shocks that solubilized zinc. Plant growth also resulted in substantial evapotranspiration, leading to an increased salinity of the CW treated effluent. A too high salinity limits the reuse of the CW treated water. Therefore, CW treatment should be followed by desalination technologies to obtain salinities suitable for reuse. In this technology train, CWs enhance the efficiency of physicochemical desalination technologies by removing organics that induce membrane fouling. Hence, P. australis planted CWs are a suitable option for the treatment of water with a salinity below 12 g/L before further treatment or direct reuse in water scarce areas worldwide, where CWs may also boost the local biodiversity.

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