Investigating the microbial quality of cooler drinking water of hospitals, clinics and health centres of Behbahan in 2014

Background and aims: The main cause of many problems in developing countries is related to the provision of safe drinking water. Since the health of drinking water is important in the busy centers such as hospitals, clinics and health centers, this study was done to investigate the role of water coolers connected to the municipal system in microbial quality of drinking water in Behbahan city. Methods: In this study, the samples were provided from all influent and effluent 30 water coolers located in hospitals, clinics and health centers in the Behbahan. They were carried out and transferred to the laboratory. Then, the amounts of total coliforms and fecal coliforms, residual chlorine, pH and temperature were measured. Collected data were analyzed using SPSS and Excel software. Results: The results showed that the average residual chlorine in input and output of the mentioned water coolers is significantly more than the standard values. Total and fecal coliforms in the input and output of water coolers are also more than the standard values. At the same time, both indicators in the output of water cooler were increased rather than the input one. By using paired t-test, a significant relationship was found between the amount of total coliform, fecal coliform and residual chlorine before and after of water cooler. Conclusions: The results showed negative effects of water coolers on microbial quality of water. If constant control, monitoring and inspections proceedings were done, these contaminations would be reduced significantly

نقش عوامل محیطی در انتقال ویروس SARS- CoV- 2 و راهکارهای کاهش آن

Background and Aims: Limited knowledge about SARS-CoV-2 transmission mechanism and the affecting factors is a global challenge. Due to the high prevalence of Covid-19 pandemic, airborne transmission of SARS-CoV-2 is more important than other modes of transmission. To investigate the airborne transmission of this virus, indoor air sampling was performed in COVID-19 ward of Sina Hospital in Ahvaz. Materials and Methods: Air samples were collected from two sampling points with a distance of less than or equal to 1 meter from the patient bed (in the patient's room) and more than 3 meters from the patient bed (in the corridor and the nurse station) Sampling was conducted through both active and passive methods. The collected samples were then transferred to the laboratory in the cold chain, where they were tested for the presence or absence of virus by reverse transcription polymerase chain reaction (RT-PCR). Ethical considerations were observed in all stages of the study. Results: Of the total air samples collected in our study, (21 samples), 9.52 % of the samples (2 samples) were positive for SARS-CoV-2, both of which were positive in the patient's room and were obtained by active air sampling method. Also, multivariate analysis showed that among the studied parameters, the highest correlation was found between the presence of virus in air samples and temperature, relative humidity, and concentration of particles in the air. Conclusion: The results indicate the presence of SARS-CoV-2 bioaerosols in the air inside the hospital.زمينه و اهداف: دانش محدود در مورد مکانیسم انتقال ویروس SARS-CoV-2 و عوامل تاثیر گذار بر آن یک چالش در مقیاس جهانی است. با توجه به شیوع بالای اپیدمی کووید-19، انتقال هوایی ویروس نسبت به دیگر راه‌های انتقال مورد توجه بیشتر می‌باشد. بنابراین در این مطالعه به بررسی نقش انتقال هوایی این ویروس، نمونه برداری از هوای داخلی بخش بستری بیماران کرونایی بیمارستان سینا اهواز انجام شد. مواد و روش‌ها: در هر یک از محل­های نمونه برداری، از دو نقطه با فاصله‌ی کمتر یا مساوی 1 متر از تخت بیماران (در اتاق بیماران) و فاصله بیش از 3 متر از تخت بیماران (در راهرو و ایستگاه پرستار) نمونه هوا به دو روش فعال و غیر فعال جمع آوری و در زنجیره‌ی سرما به آزمایشگاه منتقل شد. سپس با استفاده از واکنش زنجیره‌ای پلیمراز رونویسی معکوس (RT- PCR) برای حضور یا عدم حضور ویروس مورد بررسی قرار گرفتند. در تمام مراحل، ملاحظات اخلاقی مد نظر قرار گرفت.  يافته‌ها: از کل نمونه‌های هوای (21 نمونه) جمع‌آوری‌ شده برای حضور ویروس SARS-CoV-2، 52/9% نمونه‌ها (2 نمونه) مثبت شدند که هر 2 نمونه مثبت در اتاق بیماران و توسط روش نمونه­برداری فعال هوا ثبت شدند. تجزیه و تحلیل چند متغیره نشان داد که از بین پارامترهای مورد مطالعه، بیشترین همبستگی بین حضور ویروس در نمونه‌های هوا با دما، رطوبت نسبی، غلظت ذرات موجود در هوا به دست آمد. نتيجه‌گيري: تحقیق بیانگر وجود بیوآئروسل‌های SARS-CoV-2 در هوای داخل بیمارستان می‌باشد

Adsorption of chromium(VI) from saline wastewater using spent tea-supported magnetite nanoparticle

<p>Spent tea-supported magnetite (ST/Mag) nanoparticles were synthesized as an adsorbent for the removal of hexavalent chromium [Cr(VI)] from saline wastewater. Prepared ST/Mag adsorbent was characterized using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. Various factors affecting the uptake behavior such as pH, contact time, initial concentration of metal ions, adsorbent dose, coexisting ions, and desorption behavior were studied using batch tests. The results revealed that adsorption of Cr(VI) was highly pH dependent and the kinetics of the adsorption followed by the Avrami fractional-order and pseudo-second-order kinetic models. The results showed that the adsorption isotherms were more accurately represented by Langmuir and Liu isotherm models with a sorption capacity of 30.0 mg g⁻¹. Adsorption experiments with co-ions indicated that the adsorptive removal of Cr(VI) ions was slightly decreased. Desorption studies using alkaline eluents showed maximum recovery of ST/Mag and only 10% decrease occurring in maximum adsorption capacity after five cycles. The ST/Mag nanoparticles proved to be a very prospective adsorbent for Cr(VI) uptake from industrial high-TDS effluents.</p

Enhanced Sono-Fenton-Like Oxidation of PAH-Contaminated Soil Using Nano-Sized Magnetite as Catalyst: Optimization with Response Surface Methodology

In the current study, Fe3O4 NPs were synthesized and used as catalysts in a sono-Fenton-like process for remediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soil. The effects of operational variables were studied using central composite design (CCD) optimization approach. Results indicated that the effects of H2O2 concentration, Fe3O4 NPs dosage, ultrasonic power and pH were significant for pyrene removal as a contaminant model. In optimum experimental conditions, including H2O2 concentration of 78 mM, Fe3O4 NPs dosage of 18 mM, ultrasonic power of 313 W and pH value of 3.46, the observed pyrene removal was obtained 98.37%, which was verified through the additional experimental tests (99.33%). Pseudo first-order kinetic model was well fitted with the experimental data of pyrene removal with significant coefficient of correlation (R2: 0.9672). Accordingly, an unwashed real soil sample containing diffident PAHs (pyrene, flurene, acenaphthylene, phenenthrene, chrysene, etc) was subjected to sono-Fenton-like process based on optimized conditions. The obtained findings revealed that the removal (%) ranged between 37.7% and 85.19% for different PAHs