Noroozi , R, Mehdinezhad, Mh, Zafarzadeh A,
Volume 5, Issue 2 (Autumn – Winter 2011[PERSIAN] 2011)
Abstract
Abstract: Background and objectives: There is a great interest in photocatalytic oxidation of contaminants, using ZnO, in recent years. The main objective of this research was to study photocatalytic disinfection of E. coli bacteria as water microbial pollution index, using nano particles of ZnO and a UV lamp in a batch reactor. Material and Methods: In this study, the contaminated water sample was prepared through adding 102 and 103 E. coli bacteria per ml of raw water. The contaminated water entered the photocatalytic oxidation reactor and removal efficiency of E. coli bacteria in different conditions were studied, including pH (5.5, 7, and 9), time (10, 20, 30, 40, 50 and 60 mins), dose of nano particles ZnO (0.2,0.4,0.8 and 1 gr/l), number of bacterium (102 and 103 per milliliter) and voltage of UV-C lamp, 27 volts. Characterizations of ZnO nanoparticles were determined using scanning electron microscope equipped with Energy Dispersive X-ray Analysis (EDX) system and X-ray diffraction (XRD) method. Results: Photocatalytic process efficiency is enhanced by increasing reaction time and dose of nano particles ZnO in the presence of UV lamp irradiation. The results show that the best conditions for removal of 102 and 103 bacteria per milliliter are obtained from condition including pH of 7, reaction time of 30 mins, 0.8 gr/l doses of nano particles ZnO and 27-volt-UV lamp. Conclusion: The results indicate that the increase of reaction time and dose of nano particles ZnO, in the presence of radiation UV lamp, have the most significant effect on photocatalytic efficiency. Based on the results, photocatalytic can be promising method for removal of E. coli bacterium from drinking water. Keywords: Photocatalytic, E. coli, irradiation UV, ZnO nanoparticles, water treatment
Zahra Ahmadnia , Samane Rouhi, Hamed Mehdinezhad , Siamak Sabaghi , Alireza Firouzjahi , Mohammad Ranaei , Hossein Ghorbani , Maryam Pourtaghi, Mana Baziboron ,
Volume 18, Issue 4 (Jul-Aug 2024)
Abstract
Pasteurella species are one of the most common pathogenic bacteria in domestic animals, and they are seen more in people with weak immune systems. This research aims to investigate a case of a patient with multiple sclerosis from whose sputum Pasteurella multocida (P. multocida) was isolated. The patient was a 28-year-old man with multiple sclerosis who had persistent coughs due to food being stuck in his throat. The patient was a 28-year-old man with multiple sclerosis who had persistent coughs due to food being stuck in his throat. The primary diagnosis was pneumonia hydropneumothorax and complete collapse of the left lung. The patient's sputum culture after the first visit to the hospital was positive for P. multocida, which was not found in a second culture. In the subsequent cultures of the patient, Acinetobacter, Klebsiella, Pseudomonas aeruginosa (P. aeruginosa), and Citrobacter were found, which had extensive drug resistance to all antibiotics. In the secondary computerized tomography (CT) scan, mild pleural effusion on the left side, pneumothorax, and complete collapse with bronchiectasis was seen. Despite the treatments, the patient finally died of cardiac arrest and bradycardia. Infection with P. multocida was found in a patient with multiple sclerosis. Also, hospital-acquired infections with drug resistance caused by the weakness of the patient's system appeared in the patient who was hospitalized in the intensive care unit (ICU), and finally, the patient died. According to antibiotic patterns, the best antibiotic to which the bacteria is sensitive can be considered the primary treatment to avoid irrational antibiotic prescriptions.
