Medical waste generation in gorgan hospitals, 2014

Background and purpose: Hospitals and health-care centers are the major sources of hazardous waste generation. Hospital wastes should be collected and disposed under certain conditions. The aim of this study was to investigate hospitals waste generation in Gorgan, Iran. Materials and methods: The study was performed in 8 hospitals including 3 educational hospitals and 5 non-educational hospitals in Gorgan, 2014. Waste generation was investigated in 4 consecutive months, three times a week. Weighting was performed 384 times (48 times in each hospital). Mann-Whitney and nonparametric correlation test were used for data analysis. Results: The results showed 40.27 hazardous and 59.73 general wastes were generated in hospitals. The mean rates of waste general and hazardous generation were 2.63 and 1.03 kg/bed/day, respectively. These rates in educational and non-educational hospitals were 3.75 and 1.96 kg/bed/day, respectively. Conclusion: Generation of hazardous waste was found to be high in Gorgan hospitals. Also, the educational hospitals generated more waste than non-educational hospitals. Therefore, necessary measures should be taken to reduce the generation of waste, especially hazardous waste. © 2015, Mazandaran University of Medical Sciences. All rights reserved

Water disinfection using photocatalytic process with titanium dioxide nanoparticles

Background and purpose: Disinfection is one of the most important stages in water treatment. So far, various chemical disinfection methods such as chlorination have been widely used. However, these methods have serious disadvantages, like producing DBPs. The purpose of this research was to study the efficacy of nTiO2 photocatalyst process on removing E.Coli as a water microbial pollution index and effects of some parameters on its efficiency. Materials and methods: Water was artificially contaminated with E.Coli. Culture method and counting were performed according to standard methods for water and wastewater and was reported as CFU/ml. The size of nTiO2 was 20 nm that was used in the presence or absence of UV for disinfection. The Kolmogorov-Smirnov Test was used to check the normality of the data. The ANOVA and T-Test were used for analyzing the data. Results: The results indicated that the inactivation of Escherichia coli increased with increase of nTiO2 catalyst dose and contact time. However, the efficiency decreased when the number of colonies increased. Minimum, average and maximum percentage removal of nTiO2+UV process were 75.1, 88.9±12.7, and 100%, respectively, in 40 min contact time and 0.8 g/L catalyst dose. Conclusion: The bacteria mortality rate in the presence of UV alone was more than that of the nTiO2 alone process. However, the efficiency of the photocatalytic process (UV+nTiO2) was more than that of the UV alone or nTiO2 alone. © 2015, Mazandaran University of Medical Sciences. All rights reserved

Evaluation of rapid purification of high concentrations of 2, 4-Dinitrophenol in wastewater using catalytic ozonation with carboneus nanocomposite

Background and purpose: 2, 4-dinitrophenol (DNP) are carcinogenic and non-biodegradable pollutants that exist at high concentration in wastewater of chemical industries. In this study, treatment and removal of organic materials (COD) in wastewater was carried out by catalytic ozonation process (COP) using carbon Nano-composite catalysts. Materials and methods: This study was conducted in cylindrical 250 mL semi-continuous reactor and the effects of several parameters including pH of the solution (4-10), the amount of catalyst concentrations (0 to 4 g/L), reaction time (0 to 60 min), and saturated catalyst was studied on treatment of high concentration of DNP and the COD removal efficiency. Also, the kinetics were compared with single ozonation (SOP). Results: Removal efficiency of high concentrations of DNP (1500 mg/L) and kinetics of the COP process catalyst concentration of 4 g/L was 83 (0.0241 min-1) while the results in SOP were 50 (0.0108 min-1). The optimum pH was 6 with the reaction time of 60 min. However, the removal efficiency of COD at initial concentration of 610 mg/L in the SOP process was 61 which increased to 92 after addition of the catalyst. The main mechanism of process was chemical oxidation and a small share (3) was due to adsorption. Conclusion: The results showed that COP and this new catalyst effectively and quickly removed high concentrations of DNP and COD. This method is believed to be economic due to the short time of ozonation, recovery and reuse of the catalyst. © 2016, AMazandaran University of Medical Sciences. All rights reserved

Disinfection of effluent using catalytic ozonation process and economical comparison with chlorination

Background and purpose: Many conventional disinfection methods of effluents raise some health, efficiency and economic concerns. In order to increase the efficiency of disinfection of real effluent, in this study, the catalytic ozonation process was performed and economically compared with chlorination. Materials and methods: Magnetic activated carbon was used as acatalyst in a semi-continuous reactor for disinfection of effluent of municipal wastewater treatment plant in Bandargaz, Iran in 2015. The efficiency of disinfection was determined by thermo-tolerant coliform as indication, and the effect of parameters such as catalyst concentration (0, 0.5, 1, 2, and 5 g/L), initial number of coliforms, contact time (1, 2, 5, 10, 20 and 40 min) and catalyst reuse on disinfection process was evaluated. Finally economic comparison was done with the chlorination. Results: The results showed that the efficiency of disinfection was increased by increase in the concentration of carbon nano-composite and contact time; at 1 g/L concentration of Catalyst about 1.99 log reduction was observed after 2 min exposure time in which the effluent standards were obtained; while 1.91 log reduction of micro-organisms was measured for single ozonation. The first-order kinetics constant of single ozonation (0.42 min-1) showed an approximately 9-fold increase when the catalyst (2 g/L) was added to the solution. After 7 times reuse of nano-composite, the diminution of efficiency was negligible (1.5); and more than 57 fall of the cost was observed in a 5-year operational period compared with chlorination. Conclusion: The catalytic ozonation with the new catalyst of effluent could effectively disinfect the effluent in a short-contact-time, and due to economic considerations it can be used as an effective and economical method in wastewater treatment plants. © 2016, Mazandaran University of Medical Sciences. All rights reserved

Iran�s rural solid waste: Generation and composition

Background and purpose: Physical analysis of solid waste is the first step in waste management. In Iran, no data is available about rural solid wastes in the country. The aim of this study was to determine qualitative and quantitative analysis of rural solid wastes in Iran. Materials and methods: In this cross-sectional study, the data for national rural solid waste in 2012 was obtained from Iranian State Municipalities and Village Assistance Offices organization. Then the generation, per capita and physical composition of solid waste in rural areas in Iran were compared. Excel and SPSS V.17 were applied to analyze the data. Results: The average solid waste generation per capita was 444 g per day and total wastes in Iran�s rural areas was estimated at around 3.5 million tons per year. The majority of country�s rural solid wastes consisted of organic materials (52.53) and plastics (16) were the most valuable dry solid wastes. Conclusion: By applying composting method, not only the fertilizing capacity of the waste is used but also leachate, offensive odor and toxic gas generation would decrease. Recycling of dry solid waste in rural areas would reduce their cost of collection and disposal and also increases the profit from selling recycled materials. © 2016, Mazandaran University of Medical Sciences. All Rights reserved

Determination of hydrophobic and hydrophilic fractions of natural organic matter in raw water of Jalalieh and Tehranspars water treatment plants (Tehran)

The aim of this research was to determine hydrophobic and hydrophilic fractions of Natural Organic Matter (NOMs) in drinking water Sources of Tehran. Water sampling was conducted monthly from Aug 2006 to Jan 2007 in two drinking water treatment plants (Jalalieh and Tehranpars) in Tehran. Quantitative parameters of pH, EC, UV254 and DOC were studied based on standard methods. The XAD-7 resin method was used for fractionation of NOM. Results showed that NOM concentrations in Jalalieh and Tehranpars water treatment plants were 2.47 and 1.63 mg L-1, respectively. The mean of total percent of HPO (hydrophobic) and HPI (hydrophilic) fractions were about 41 and 59, respectively. Since the hydrophobic NOM fraction exhibits higher trihalomethane formation potential (THMFP) than hydrophilic NOM, Tehran water chlorination exhibits higher THMFP than halo acetic acid formation potential (HAAFP). The information obtained from this study may be further employed in the design of the control technique and management strategies for the water treatment plant, especially for DBP, reduction. © 2007 Asian Network for Scientific Information

Economic aspects of dry solid waste recycling in Shiraz, Iran

Background and purpose: Nowadays, in developed countries, the economic profits of recycling and its role in waste reduction and disposal costs is well recognized. In this study, the economic aspects of dry solid waste recycling were evaluated in Shiraz, Iran. Materials and methods: A descriptive cross-sectional study was conducted in Shiraz in which data was collected through field observations, interviews with officials of municipal utilities and investigating the documents in the organization. Then, the economic benefits of different recycling rates including 15 (current), 50 and 80 were evaluated. Results: The recycling rate of waste paper, cardboard, glass, nylon and plastic carrier bags, disposable plastic containers, PET, other types of plastic, disposable metallic containers, and other types of metals were 23, 12, 8, 2.5, 8, 13, 13, 11, and 12, respectively. The total economic benefits of recycling in terms of current recycling (15), desirable recycling (50) and ideal recycling (80) rates were calculated as 11527, 39869, and 63791 million Rials per year, respectively. Conclusion: Only 15 of dry solid waste is recycled in Shiraz. The economic benefits from recycling could increase to 8-18 times of the current benefit with a 10 to 20 year proper planning and upgrading the current recycling program. © 2016, AMazandaran University of Medical Sciences. All rights reserved

Eco-friendly green synthesis of novel magnetic Fe3O4/SiO2/ZnO-Pr6O11 nanocomposites for photocatalytic degradation of organic pollutant

This study reports the successful sonochemical synthesis of novel Fe3O4/SiO2/ZnO-Pr6O11(Fe/Si/Zn–Pr6O11) nanocomposites using fructose as a green capping agent. The influence of various parameters containing capping agent, power and time of ultrasound irradiation was investigated to reach optimum morphology and size conditions. The products obtained were characterized by transmission electron microscopy (TEM), UV/Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectra (FT-IR), vibration sample magnetometer (VSM), scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDS) and X-ray diffraction (XRD). The Fe3O4/SiO2/ZnO-Pr6O11 nanocomposites display remarkably enhanced photocatalytic activity towards rhodamine b degradation (89.6%) and Congo red (84.7%) under UV irradiation compared with the other products. The results illustrate that the photocatalytic efficiency of magnetic nanocomposites is very much higher than pure Pr6O11 nanostructures. Magnetic photocatalyst still has good stability after five successive runs. So, these recyclable nanocomposites can play a role in the treatment of both industrial and domestic contaminated water

Effect Of Hydrophilic And Hydrophobic Organic Matter On Amoxicillin And Cephalexin Residuals Rejection From Water By Nanofiltration

Antibiotics such as amoxicillin and cephalexin are a group of pharmaceutical compounds in human medicine practice that have been entered in water bodies. Presence of these compounds in the environment has raised concerns regarding the toxicity to aquatic organisms and the emergence of strains of antibiotic-resistant bacteria. Removal of these substances before entering the aquatic environment as well as water reuse plant is very important. The objective of this investigation was to evaluate the impact of hydrophilic and hydrophobic fractions of Natural Organic Matter (NOM) on the removal efficiency of cephalexin and amoxicillin, by using two different commercially available composite NF membranes (TFC-SR2 and TFC-SR3). In addition, the effect of NOM fractions on retention mechanism and permeates flux behavior was studied. Amoxicillin and cephalexin were used as models of antibiotics; alginate and humic acid were used as models of hydrophilic and hydrophobic fractions of NOM, respectively. It was observed that the rejection and permeate flux of amoxicillin and cephalexin were influenced by the membrane characteristics and properties of NOM. The results showed that as the alginate proportion was increased, the rejection improved. The permeate flux decreased with increasing alginate ratio. It was observed that the rejections of amoxicillin and cephalexin in TFC-SR2 were >97.3% and >95.8% in all experiments, respectively. In TFC-SR3, the rejection percentage were (95.9%-100%) and (86.1%-96.3%), respectively. Alginate and humic acid had synergistic effect on flux decline. In other words, increasing alginate concentration increased the rate and extent of flux reduction

Application of magnetic activated carbon as a catalyst in catalytic ozonation process (Cop) for removal and mineralization of humic acid from aqueous solution

Humic acid (HA) is a natural organic matter, which is naturally present in raw water sources due to the decomposition of dead animals and plants. Therefore, the catalytic properties of a carbonaceous nanocomposite in the catalytic ozonation process (COP) of HA were investigated, and the results were compared with those obtained from the single ozonation process (SOP). Magnetic carbona-ceous nanocomposite, as a novel catalyst, was applied to optimize the conditions for the removal of HA in the COP, and the influential parameters such as pH, retention time, catalyst dosage, and addition of radical scavengers were all evaluated. This is an experimental study in which the removal of HA by a COP was investigated in a cylindrical glass reactor (a useful volume of 250 mL) with a semi-continuous flow. Catalyst raw material was the granular activated carbon (GAC) that has been stabilized on Fe3 O4 nanoparticles by the calcination method. The results revealed that by increasing the retention time, pH, and catalyst dosage, HA and TOC removal efficiencies by both process (SOP and COP) was increased. The highest removal efficiencies of HA and TOC in the COP process were 95 and 87.67, respectively while their removal efficiencies in the SOP process were 76.8 and 67.1 under the conditions including pH of 9, contact time of 60 min, and HA concentrations of 15 mg/L. The highest removal of the HA by the SOP and catalyst adsorption was obtained to be 76 and 5.8 after 60 min, respectively; however, it was observed to be 95.7 in the COP, in the same contact time. The presence of tert-butanol alcohol (TBA) did not significantly affect the removal of the HA in the COP. Practically, this study revealed that the magnetically activated carbon catalyst could be potentially employed in the COP for the treatment of the water having average concentrations of HA substances. © 2021 Desalination Publications. All rights reserved