Sara Kahvaei; Afshin Takdastan; Reza Jalilzadeh Yengejeh
Abstract
Background: Nowadays, the discharge of effluents containing chemicals through manufacturers or consumer industries causes major environmental problems. In this study, we assessed the effect of sludge reversal of the clarifier unit on enhancing the coagulant performance of Poly-Aluminum chloride in the ...
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Background: Nowadays, the discharge of effluents containing chemicals through manufacturers or consumer industries causes major environmental problems. In this study, we assessed the effect of sludge reversal of the clarifier unit on enhancing the coagulant performance of Poly-Aluminum chloride in the removal of turbidity/COD/PVC from PVC effluent of Bandar Imam Khomeini petrochemical plant and reduction of the amount of coagulant and costs. Methods: The experiments were carried out by Jar test with poly aluminum chloride (PAC); the returned sludge, as the assisting coagulant, and the amplitude of the differentiates including (5.5-11) pH of coagulant concentration (10-140mg/L) and concentration of returned sludge (2-20 ml) were investigated. To ensure the accuracy and precision, we repeated each stage of the experiment three times. Results: The results showed that the most optimal conditions for coagulant were at pH=8 and the optimum dose of poly aluminum chloride was 25 mg/L plus 5ml of the clear sludge volume in the clarifier. The removal efficiency of turbidity, COD, and PVC under optimum conditions of Poly-Aluminum chloride were reported 99.71%, 97.19%, and 99.55%, respectively. Conclusion: The results indicated that the sludge of the clarifier, as the main assisting coagulant, in addition to increasing the efficiency of the removal turbidity of COD and PVC reduced the dose of the main coagulant.
Masoomeh Ghanavat Amani; Reza Jalilzadeh Yengejeh
Abstract
Background: The main aspect of water purification to serve the human drinking purpose is the elimination of microbial agents and pathogens using the disinfectants. Although chemicals such as chlorine are the most common water disinfectants, the researchers have always sought to identify and ...
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Background: The main aspect of water purification to serve the human drinking purpose is the elimination of microbial agents and pathogens using the disinfectants. Although chemicals such as chlorine are the most common water disinfectants, the researchers have always sought to identify and introduce new disinfectants due to the formation of potentially carcinogenic byproducts. Owing to the high efficiency and lack of hazardous residues, nanoparticles have recently been used in many scientific activities. Objectives: In this study conducted in summer 2018, the copper and silver nanoparticles were used to remove Escherichia coli (E. coli) and Klebsiella from the synthetic and real samples. Methods: This experimental study was performed on Nano particles and by adding nanoparticles to samples (real and synthetic), the efficiency of removal of E. coli and Klebsiella was measured by MPN and pure plate methods. Results: By optimizing the conditions, in 200 ppm concentration as 2ml with pH=7, it has the highest removal rate of 99.25% for E. coli, and in 250ppm concentration as 1.5 ml with pH = 7, it has the removal rate of 81.25% for Klebsiella. Conclusions: In this case study, we found that using Nano particles led to high level of efficiency at a short time; moreover, they were cost-effective and environmentally friendly.
Azadeh Mehrdoost; Reza Jalilzadeh Yengejeh; Mohammad Kazem Mohammadi; Ali Akbar Babaei; Azadeh Haghighatzadeh
Abstract
Background: Pharmaceutical pollutants are one of the most important pollutants for water resources, and their health and environmental effects have been well estimated.Absorption is one of the best methods of the removal of antibiotics using nanocomposite.
Methods: This experimental study was performed ...
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Background: Pharmaceutical pollutants are one of the most important pollutants for water resources, and their health and environmental effects have been well estimated.Absorption is one of the best methods of the removal of antibiotics using nanocomposite.
Methods: This experimental study was performed on Nano composites. The PAC/Fe/Si/Zn Nano composite was successfully synthesized using a co-precipitation method in which iron (Fe), silicon (Si) and zinc (Zn) were loaded on the activated carbon powder (PAC). The structural features of the as-synthesized Nano composite were determined using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). The as-synthesized Nano composite was utilized to remove azithromycin and cefixime from aqueous solution with the assistance of UV light. The effect of operational parameters such as pH, irradiation time, initial azithromycin/cefixime concentration and Nano composite dose on UV-assisted removal performance was evaluated using an optimization process.
Results: The UV-assisted removal activities indicated more removal percentage (99.7%) for azithromycin compared to cefixime (95.6%). The kinetics of removal was tested using Langmuir-Hinshelwood model, indicating the first-order reaction kinetics as the best model for UV-assisted removal of both azithromycin and cefixime. Adsorption equilibrium data were modeled using Langmuir and Freundlich isotherms. Azithromycin equilibrium adsorption showed a good fit with both Langmuir and Freundlich models, while the most suitable model for cefixime adsorption was estimated to be Langmuir isotherm.
Conclusion: The findings showed that PAC/Fe/Si/Zn Nano composite were well able to degrade non-biodegradable antibiotics in aqueous solutions, which is very valuable from environmental aspects.
Masoud Yousefi; Kourosh Rahmani; Reza Jalilzadeh Yengejeh; Sima Sabzalipour; Gholamreza Goudarzi
Abstract
Background: The production and consumption of pharmaceutical compounds, including antibiotics, and their entry into the environment have raised concerns for experts. It is important to find appropriate methods for treatment of these pollutants from aquatic environments. In this study, nano-persulfate ...
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Background: The production and consumption of pharmaceutical compounds, including antibiotics, and their entry into the environment have raised concerns for experts. It is important to find appropriate methods for treatment of these pollutants from aquatic environments. In this study, nano-persulfate process using green synthesis of zero iron nanoparticles was used in decomposition of the antibiotic Metronidazole (MNZ). Methods: In this study, first, zero iron nanoparticles were synthesized using oak leaves. Then, the characteristics of these nanoparticles were determined using electronic images such as SEM, and TEM. In the experimental part of the study, the effect of operating conditions such as nZVI dosage, persulfate concentration and pH of the PS/nZVI process on degradation of MNZ in aqueous solution Was examined. Results: The results of this study showed that the PS/nZVI process had an acidic nature for removal of MNZ. The optimal conditions for this process were: the dosage of nZVI was 1.8 g/l, the concentration of persulfate was 1.5 mg/l, and pH was 3 for the degradation of 50 mg/l MNZ at contact time of 90 min. The maximum MNZ removal efficiency using PS / NZVI process was about 98.4 % in these conditions. Conclusion: It can be concluded that the synthesis of green zero iron nanoparticles is an economical and environmentally friendly method that can be used to remove MNZ from aqueous solutions.
