Avicenna Journal of Environmental Health Engineering
Volume:2 Issue: 2, Dec 2015

The evaluation of both qualitative and quantitative factors regarding biomedical waste can help remedy the shortcomings of the current hospital waste management (HWM) system. The present study used a questionnaire and a weighing operation to investigate the perceived quality of HWM and the quantity of biomedical waste in Valiasr hospital, Nurabad district, Mamasani county, Iran, from July to September 2013. For 21 days, at the end of each shift, all hospital waste was weighed using scales. In addition, a 21-item questionnaire concerning perceptions of the quality of waste division, collection, storage, and transportation was administered to 40 hospital employees. The results of the weighing operation revealed that the hospital generated 417.99 kg of waste per bed per day (kg/bed-day). Considering that there are 96 beds actively used in the hospital, the average kg/bed-day of waste generated was 2.32 kg/bed-day of infectious waste, 0.03 kg/bed-day of sharps, and 2 kg/bed-day of household waste. The highest amount of infectious waste was generated in the emergency unit and the second highest in the operating rooms. In addition, analysis of questionnaire responses showed that most participants classified HWM activities as good, including waste division (65%), collection and transport to temporary waste storage (77.5%), and transport to the disposal zone (80%). Improper division of wastes by employees and visitors increased the volume of waste identified as infectious by mistakenly adding non-infectious waste to the bags of infectious waste. To reduce the volume of waste identified as infectious, division of wastes must be properly implemented and scrupulously maintained.

Since the process of heterogeneous Fenton is more complex and dynamic than the common Fenton process, control and online monitoring is entirely vital for optimum operation of this system. This study was aimed to investigate the effects of pH, oxidation-reduction potential (ORP) and dissolved oxygen (DO) variations on dimethyl phthalate (DMP) removal from aqueous solutions using the heterogeneous Fenton process with nano zero-valent iron (nZVI). Parameters affecting the process like contact time (5 - 120 minutes), pH (2 - 10), H2O2 concentration (0.01 - 1 mmol/L) nZVI content (0.01 - 0.5 g/L) and initial DMP concentration (2 - 50 mg/L) were also studied. It was found that, at optimum amounts (pH = 4, H2O2 concentration = 0.1 mmol/L, nZVI = 0.05 g/L, initial DMP concentration = 2 mg/L, and contact time = 60 minutes), approximately 98% of the pollutant was removed. This process could treat DMP well from aqueous environments and can be introduced as a cheap and effective method.

Members of the genus Bdellovibrio are small and highly motile Gram-negative predators of other Gram-negative bacteria. Bdellovibrio enters the prey cell, transforming it into a structure that is referred to as a bdelloplast. It then grows and divides inside the bdelloplast, ending in lysis and the release of the Bdellovibrio progeny. Because of this capability, Bdellovibrio is a potential antibacterial agent. In this article, we report the results of studies on the interactions of Bdellovibrio with actively growing and viable but nonculturable (VBNC) Vibrio cholerae. A significant observation was that Bdellovibrio attacked both VBNC and actively growing V. cholerae. These results indicate that Bdellovibrio, a “living antibiotic,” has potential as an antibacterial agent in environmental and public health bioprotection.

In the current study, the life cycle assessment (LCA) method was used to expect the emissions of different environmental pollutants through qualitative and quantitative analyses of solid wastes of Qazvin city in different final disposal methods. Therefore, four scenarios with the following properties considering physical analysis of Qazvin’s solid wastes, the current status of solid waste management in Iran, as well as the future of solid waste management of Qazvin were described. In order to detect the quantity of the solid wastes, the volume-weighted analysis was used and random sampling method was used for physical analysis. Of course, regarding the method of LCA, it contains all stages from solid wastes generation to its disposal. However, since the main aim of this study was final disposal stage, the emissions of pollutants of these stages were ignored. Next, considering the mixture of the solid waste, the amount of pollution stemming from each of final disposal methods from other cities having similar conditions was estimated. The findings of the study showed that weight combination of Qazvin solid wastes is entirely similar to that of other cities. Thus, the results of this study can be applied by decision makers around the country. In scenarios 1 and 2, emission of leachate containing high amounts of COD and BOD is high and also the highest content of nitrate, which can contaminate water and soil resulting in high costs for their management. In scenarios 3 and 4, the amounts of gaseous pollutants, particularly CO2, as well as nitrogen oxides are very high. In conclusion, the LCA methods can effectively contribute to the management of municipal solid wastes (MSW) to control environmental pollutants with least expenses.

Cystoisospora spp., formerly known as Isospora spp., are coccidian parasitic protozoan with several species infecting a wide variety of organisms such as humans, felines and canines. This study was designed to evaluate the prevalence of Cystoisospora spp. oocysts in the soil collected from Kermanshah city, the west of Iran. One hundred and ninety-two soil samples were collected from six regions of Kermanshah city, including two regions in the city center as well as one region in each of the east, south, north and west regions. Regarding that this study was first of its kind in this region, the sampling method was according to judgmental sampling. Overall, from each region, 32 soil samples were collected, 16 of which were obtained from public parks and 16 other ones from primary schools. The Cystoisospora spp. oocysts were isolated from soil samples using the flotation method, then stained temporarily and permanently with Lugol’s solution and modified Ziehl-Neelsen methods, respectively, and examined under a light microscope. Out of 192 soil samples, 15 (7.8 %) cases were infected with Cystoisospora spp. oocysts. In the public parks, the highest prevalence of oocysts was observed in the center 1 and the south regions, both with 12.5% prevalence. Moreover, in the primary school regions, the highest prevalence was observed in the center 2 (18.75 %) region followed by the east and west (both 12.5 %) regions. The findings of the present study revealed the potential of Cystoisospora spp. transmission in the west of Iran, and that the contamination of soil in primary schools was higher than public parks.

Pentachlorophenol (PCP), which is one of the resistant phenolic compounds, has been classified in the category of EPA’s priority pollutants due to its high toxicity and carcinogenic potential. Therefore, its removal from water and wastewater is very important. Various methods have been studied for removing the compound, among which advanced oxidation processes (AOPs) have attracted much attention because of ease of application and high efficiency. Thus the aim of this study was to investigate the efficiency of the UV/ZrO2/H2O2 process, as an AOP, for PCP removal from aquatic environments. The effects of several parameters such as ultraviolet (UV) exposure time, initial PCP concentration, pH, concentration of zirconium dioxide (ZrO2) nanoparticles, and H2O2 concentration were studied. Kinetics of the reaction was also detected. The concentration of the stated materials in the samples was determined using a spectrophotometer at 500 nm. The results showed that the highest efficiency (approximately 100%) was reached at optimized conditions of pH 6, contact time of 30 minutes, initial PCP concentration of 20 mg/L, the nanoparticles concentration of 0.1 g/L and H2O2 concentration of 14.7 mM/L. Also, the process followed the first order kinetics reaction. The obtained results illustrated that the UV/ZrO2/H2O2 process has a high ability in removing PCP.

Compared to other medical clinics, dental centers produce a relatively small amount of healthcare waste. However, they are responsible for the production of certain amounts of waste that can cause serious health and environmental hazards if not treated properly. Determining the quantity and quality of dental waste is quite necessary to plan the machinery, personnel, and transportation methods. In the current analytical cross-sectional study, 22 dental clinics were randomly selected from among 145 dental centers in Yazd. For each clinic, three samples were manually collected and distributed at the end of the work day once a week (the day was randomly chosen). The components were classified into four groups based on their characteristics and potential risk. Afterward, the collected data were analyzed using Excel. The mean per capita daily waste generation in the Yazd dental clinics was 80.179 g for each patient. In general, the Yazd dental clinics generate approximately 4 tons of waste every year. Out of this amount, infectious waste, domestic waste, chemical-pharmaceutical waste, and sharp waste account for 49.30%, 33.33%, 13.7%, and 4.2%, respectively. The results of the current study and the small amount of waste generated in Yazd suggest that a special safe site should be constructed for infectious, sharp, and keen waste; private companies should collect such waste and transfer it to this site after the waste is disinfected; and the waste should then be transferred to a municipal waste hygienic disposal site. In regard to chemical waste that may contain hazardous materials, like mercury, no suggestions other than safe burial are made.

A study was conducted to treat stabilized leachate by applying polyaluminium chloride (PAC) and tobacco leaf extract as a coagulant and coagulant aid. Experimental results indicated that the tobacco leaves were positively charged. The removal rate of the chemical oxygen demand, using 1500 mg/L PAC as a sole coagulant, was approximately 63% and increased to 91% when 1000 mg/L PAC was mixed with 1000 mg/L tobacco leaf. Additionally, 1500 mg/L PAC with 250 - 1000 mg/L tobacco leaf and 54% ammoniacal nitrogen was removed, compared with only 46% reduction using 1500 mg/L with only 46% reduction.