scholarly journals Factors Determining the Removal Efficiency of Procion MX in Waters Using Titanate Nanotubes Catalyzed by UV Irradiation

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Vo Nguyen Xuan Que ◽  
Tran Tien Khoi ◽  
Nguyen Thi Thuy ◽  
Ta Thi Minh Dung ◽  
Dao Thi Thanh Binh ◽  
...  

The treatment of wastewater from the textile industry containing organic dyes faces many challenges since these compounds resist the biodegradation process in conventional treatment units. Among the physicochemical processes, photocatalysis is considered a facile, cheap, and environmental-friendly technology for treating persistent organic pollutants in waters at low concentrations. This study investigated several physicochemical factors determining the photocatalytic activity of titanate nanotubes (TNTs) to remove Procion MX 032 (PMX), an azo dye, in waters. Degradation of PMX by photocatalytic oxidation process at room temperature (30°C) was set up with the UV irradiation in the presence of different types of photocatalyst such as ST-01 (100% anatase), industrial TiO2, TNTs calcined at 120°C and 500°C. Effect of reaction time, catalyst amount, pH, light wavelength and intensity, and oxidants was investigated. Consequently, TNTs calcined at 500°C provided the highest removal efficiency. The photocatalytic oxidation of PMX by TNT calcined at 500°C was affected by pH variation, getting the highest removal at pH of 8, and inhibited with the presence of H2O2 and O2. Particularly, the PMX degradation using titanate nanotubes was optimized under the UV-A intensity of 100 W/m2. The dye was degraded by more than 95% at the TNTs concentration of 75 mg/L and pH 8.0 after 90 min. The results suggest that photocatalysis using TNTs can be a simple but efficient treatment method to remove PMX and potentially be applied for the treatment of wastewaters containing dyes.

2013 ◽  
Vol 9 (2) ◽  
pp. 132-136

Photocatalysis by titanium dioxide (TiO2) is a water treatment method. Pseudomonas aeruginosa is a microorganism resistant to chlorine and UV-C irradiation. TiO2 photocatalytic technology can destroy bacteria, which are resistant to oxidative destruction of cell membrane caused by sole UV irradiation. This study aims to investigate the total mineralization of the bacterium (P. aeruginosa) to the extent of death and cell-mass destruction using TiO2 photocatalytic oxidation process. In this work the effects of parameters such as amount of TiO2, irradiation time, initial concentration of bacterium, presence of ascorbic acid and effect of cell wall on removal of P. aeruginosa were studied. The data, which were obtained in this study, showed that the optimum concentration of TiO2 was 325 ppm. Also at the initial concentration of TiO2 equal to 325 ppm and initial microorganism MPN / 100 ml equal to 300 and after 75 min UV irradiation time, P. aeruginosa removal efficiency was 94.3 %. Removal efficiency of P. aeruginosa in the absence of TiO2 or UV irradiation was very low. Decreasing the concentration of microorganisms increased its removal efficiency. Removal efficiency of spheroplast cells was more than intact cells of P. aeruginosa, which shows the important role of cell wall on cell resistance against chemical agents. Ascorbic acid had inhibitory effect on this process.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Haibao Huang ◽  
Xinguo Ye ◽  
Huiling Huang ◽  
Peng Hu ◽  
Lu Zhang ◽  
...  

Benzene is a toxic air pollutant and causes great harm to human being. Photocatalytic oxidation (PCO) has been frequently studied for benzene removal, however, its PCO efficiency is still very low and the photocatalysts are easy to be deactivated. To improve the efficiency and stability of PCO, UV lamps with partial 185 nm UV irradiation were used to activate photocatalysts (denoted as 185-PCO). Cobalt modified TiO2(Co-TiO2) was developed to improve the PCO activity and eliminate ozone generated from 185 nm UV irradiation. Results show that benzene removal efficiency of PCO with 254 nm UV irradiation (denoted as 254-PCO) is only 2.1% while it was greatly increased to 51.5% in 185-PCO. 185-PCO exhibited superior capacity for benzene oxidation. In the 185-PCO process, much ozone was left in case of TiO2as photocatalysts while it can be nearly eliminated by 1% Co-TiO2.


2010 ◽  
Vol 26-28 ◽  
pp. 637-640
Author(s):  
Wen Jie Zhang ◽  
Ru Yuan Li ◽  
Jia Wei Bai

Photoelectrochemical (PEC) degradation of Procion Red MX-5B was investigated in aqueous Na2SO4 solution. Higher electrolyte concentration resulted in higher current between the electrodes due to increased conductivities of the solutions. UV irradiation could obviously raise the current, and the differences became larger in accordance with the increase of the applied potentials. The pH declined in the first 30 minutes and became constant for the prolonged reaction time during both PEC degradation and photocatalytic oxidation. The applied potential could only slightly improve dye decolorization. Although a potential of 8 V was applied to 0.3 mol/l Na2SO4 solution, TOC removal efficiency of PEC degradation was almost as the same as that of photocatalytic oxidation.


2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Hanane Afanga ◽  
Hicham Zazou ◽  
Fatima Ezzahra Titchou ◽  
Youness Rakhila ◽  
Rachid Ait Akbour ◽  
...  

AbstractTextile wastewater containing toxic dyes needs efficient treatment before being released into the environment. Certain dyes are known or presumed to have carcinogenic potential for humans. In this work, hybrid electrochemical processes including electrocoagulation (EC) alone and combined with electro Fenton (EF), anodic oxidation (AO) and peroxi-coagulation (PC) were tested to treat real textile wastewater using a batch reactor. A sequential EC and EF (EC-EF) process was found to be more effective. The experimental results indicated that the effectiveness of the treatment decreases in the following order: EC-EF > EC-AO > EC-PC > EC. EC-EF results showed a decrease in chemical oxygen demand (COD, 97%), total organic carbon (98%), total suspended solids (98%), and the concentration of metal species; showing that the treatment of such wastewater type can be achieved by combined EC-EF process in a one-pot bench-scale reactor. The electrical energy consumption, the iron dissolution, and the biological oxygen demand/COD ratios of EC and EC-EF processes were evaluated. Characterization of the sludge generated during EC treatment at current density of 20 mA cm− 2 was carried out. Precipitation, adsorption, and electrochemical oxidation/reduction of organic dyes and metallic ions occurred during the treatment. This investigation shows the efficiency of combined EC-EF to treat textile wastewater.


1992 ◽  
Vol 25 (1) ◽  
pp. 83-92
Author(s):  
Pentti Väänänen ◽  
Pekka Pouttu ◽  
Timo Kulmala

The National Board of Waters in Finland has proposed a study on the joint treatment of industrial and municipal wastewaters of the City of Kotka. This study is of great interest due to the large forest products industry and food industry in Kotka. All of the wastewaters from the forest products and the food industry and the municipal sewage have been found to be suitable for biological treatment, which makes the joint treatment applicable. An activated sludge process is selected because it takes advantage of the large amount of nutrients in the municipal sewage and it has proved to be the most efficient treatment method for forest industry wastewaters. However, municipal wastewater contains more nutrients than needed for the biological process, which can cause eutrophication problems in the watercourse. To reduce the pollution caused by the nutrients, chemical treatment of the wastewater is also proposed in the joint treatment. It was concluded that the joint treatment of wastewater is economically, technically and environmentally the best way to arrange wastewater treatment for the industry and the city.


2019 ◽  
Vol 25 (34) ◽  
pp. 3645-3663 ◽  
Author(s):  
Muhammad Ismail ◽  
Kalsoom Akhtar ◽  
M.I. Khan ◽  
Tahseen Kamal ◽  
Murad A. Khan ◽  
...  

: Water pollution due to waste effluents of the textile industry is seriously causing various health problems in humans. Water pollution with pathogenic bacteria, especially Escherichia coli (E. coli) and other microbes is due to the mixing of fecal material with drinking water, industrial and domestic sewage, pasture and agricultural runoff. Among the chemical pollutants, organic dyes due to toxic nature, are one of the major contaminants of industrial wastewater. Adequate sanitation services and drinking quality water would eliminate 200 million cases of diarrhea, which results in 2.1 million less deaths caused by diarrheal disease due to E. coli each year. Nanotechnology is an excellent platform as compared to conventional treatment methods of water treatment and remediation from microorganisms and organic dyes. In the current study, toxicity and carcinogenicity of the organic dyes have been studied as well as the remediation/inactivation of dyes and microorganism has been discussed. Remediation by biological, physical and chemical methods has been reviewed critically. A physical process like adsorption is cost-effective, but can’t degrade dyes. Biological methods were considered to be ecofriendly and cost-effective. Microbiological degradation of dyes is cost-effective, eco-friendly and alternative to the chemical reduction. Besides, certain enzymes especially horseradish peroxidase are used as versatile catalysts in a number of industrial processes. Moreover, this document has been prepared by gathering recent research works related to the dyes and microbial pollution elimination from water sources by using heterogeneous photocatalysts, metal nanoparticles catalysts, metal oxides and enzymes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Phitchan Sricharoen ◽  
Supalak Kongsri ◽  
Chunyapuk Kukusamude ◽  
Yonrapach Areerob ◽  
Prawit Nuengmatcha ◽  
...  

AbstractWe report a novel method for the synthesis of 3-mercaptopropyl trimethoxysilane-modified hydroxyapatite (FHAP-SH) derived from fish-scale residues by using ultrasound irradiation. Scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were used for the FHAP-SH characterization. Then, the organic dye adsorption on the FHAP-SH was monitored through an ultrasound process. After the dye removal optimization, significant improvements were observed in the maximum adsorption capacities for Congo Red (CR, 500 mg g−1), Coomassie Brilliant Blue G 250 (CB, 235 mg g−1), and Malachite Green (MG, 625 mg g−1). The adsorption behaviors of these dyes were fitted by using the Langmuir isotherm model with a high coefficient of determination values ranging from 0.9985 to 0.9969. The adsorption of the three dyes onto FHAP-SH was an endothermic process based on the adsorption thermodynamics model, while the adsorption kinetics analysis of the dyes presented a good alignment with the pseudo-second-order kinetics. The FHAP-SH exhibits a remarkably high adsorption capacity, is inexpensive, and fulfills the ecofriendly requirements of dye wastewater treatment, especially in the textile industry.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Garima Rathee ◽  
Amardeep Awasthi ◽  
Damini Sood ◽  
Ravi Tomar ◽  
Vartika Tomar ◽  
...  

Abstract It would be of great significance to introduce a new biocompatible Layered Double Hydroxide (LDH) for the efficient remediation of wastewater. Herein, we designed a facile, biocompatible and environmental friendly layered double hydroxide (LDH) of NiFeTi for the very first time by the hydrothermal route. The materialization of NiFeTi LDH was confirmed by FTIR, XRD and Raman studies. BET results revealed the high surface area (106 m2/g) and the morphological studies (FESEM and TEM) portrayed the sheets-like structure of NiFeTi nanoparticles. The material so obtained was employed as an efficient adsorbent for the removal of organic dyes from synthetic waste water. The dye removal study showed >96% efficiency for the removal of methyl orange, congo red, methyl blue and orange G, which revealed the superiority of material for decontamination of waste water. The maximum removal (90%) of dyes was attained within 2 min of initiation of the adsorption process which supported the ultrafast removal efficiency. This ultrafast removal efficiency was attributed to high surface area and large concentration of -OH and CO32− groups present in NiFeTi LDH. In addition, the reusability was also performed up to three cycles with 96, 90 and 88% efficiency for methyl orange. Furthermore, the biocompatibility test on MHS cell lines were also carried which revealed the non-toxic nature of NiFeTi LDH at lower concentration (100% cell viability at 15.6 μg/ml). Overall, we offer a facile surfactant free method for the synthesis of NiFeTi LDH which is efficient for decontamination of anionic dyes from water and also non-toxic.


2016 ◽  
Vol 75 (3) ◽  
pp. 619-628 ◽  
Author(s):  
Melike Isgoren ◽  
Erhan Gengec ◽  
Sevil Veli

This paper deals with finding optimum reaction conditions for wet air oxidation (WAO) of malathion aqueous solution, by Response Surface Methodology. Reaction conditions, which affect the removal efficiencies most during the non-catalytic WAO system, are: temperature (60–120 °C), applied pressure (20–40 bar), the pH value (3–7), and reaction time (0–120 min). Those were chosen as independent parameters of the model. The interactions between parameters were evaluated by Box-Behnken and the quadratic model fitted very well with the experimental data (29 runs). A higher value of R2 and adjusted R2 (>0.91) demonstrated that the model could explain the results successfully. As a result, optimum removal efficiency (97.8%) was obtained at pH 5, 20 bars of pressure, 116 °C, and 96 min. These results showed that Box–Behnken is a suitable design to optimize operating conditions and removal efficiency for non-catalytic WAO process. The EC20 value of raw wastewater was measured as 35.40% for malathion (20 mg/L). After the treatment, no toxicity was observed at the optimum reaction conditions. The results show that the WAO is an efficient treatment system for malathion degradation and has the ability of converting malathion to the non-toxic forms.


2011 ◽  
Vol 117-119 ◽  
pp. 786-789 ◽  
Author(s):  
Wen Churng Lin ◽  
Wein Duo Yang ◽  
Zen Ja Chung ◽  
Hui Ju Chueng

Titanate nanotubes were synthesized at various hydrothermal temperatures and reaction times by the hydrothermal process and used as photocatalyst. BET analysis was conducted in order to find out the surface area of these as-prepared samples and it was found that the surface area increases with rise in temperature till 130 oC. Synthesized as-prepared titanate nanotubes were applied on methylene blue degradation from aqueous media by UV irradiation. It was observed that dye removes ~99% from the aqueous media at a titanate nanotubes dose of 2 g/L.


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