Archives of Hygiene Sciences
Volume:6 Issue: 3, Summer 2017

Background & Aims of the Study: There are three different types of fibers used in the manufacture of various textile products: cellulose fibers, protein fibers and synthetic fibers. Textile wastewater discharge into the environment leads to irreparable damages. The main purpose of this study was treatment of textile wastewater, using a combined coagulation and dissolved air flotation (DAF) processes, Iran in 2016.
This study was an empirical-lab study which the Jar tests and DAF were used in laboratory scale. After determination of the optimal condition of pH and the optimum of concentration of poly-aluminum chloride by Jar test, the effect of the effective parameters including the concentration of the coagulant (10, 20, 30, 40, 60 mg/L), coagulation time (5, 10, 15 and 20 min), flotation time (5, 10, 15 and 20 sec), saturation pressure ( 3, 3.5, 4 and 4,5 atm) and turbidity ( 10, 20 , 30, 40, 60 NTU) on the removal efficiency of COD, BOD5 and TSS by DAF were studied.
Results of this study showed that the DAF process can treatment COD, BOD5 and TSS up to85.7%, 80.68% and 95.6%, respectively. The appropriate condition was as follows: pH=6, initial concentration of aniline= 200 mg/L, flocculation time = 10 min, flotation time= 20 sec and the air pressure= 4 atm. Also, this study indicates that the DAF process to conclusion requires a lower dosage of poly-aluminum chloride.
The coagulation and DAF processes can be effective to treat textile wastewater from industries.

Background & Aims of the Study: Rhodococci according to possess large genome, their active metabolism and survival under extreme conditions, are highly regarded for biodegradation and bioremediation of different pollutants especially heavy metals in the environment. Biofilms are more resistant to heavy metals than free-swimming organisms. The aim of this study was biofilm formation of two native Rhodococcus strains (Rhodococcus rhodochrous and Rhodococcus rhodnii) and comparative evaluation effects of heavy metals such as lead, copper, zinc, chromium and cadmium in various concentrations against biofilm and planktonic cells that carried out at the first time.
Bacterial strains used in this investigation were isolated from agricultural soils in Qom, Iran. Biofilm formation was performed at 30 °C and 37 °C in tryptic soy broth (TSB) and brain heart infusion (BHI) broth, at 24,48,72 and 96 hours in 96-well microplate. Minimum inhibitory concentration (MIC) of heavy metals in various concentrations for planktonic cells was determined, using microdilution and macrodilution methods. Minimum biofilm inhibitory concentration (MBIC) and Minimum biofilm eradicating concentration (MBEC) in various concentrations of heavy metals for biofilm cells were evaluated by microdilution method. The result of this study confirmed, using scanning electron microscope (SEM).
The best condition for biofilm formation of native R.rhodochrous isolate was determined after incubation at 37°C in BHI broth, at 96 hours and the best condition for biofilm formation of native R.rhodnii isolate was determined at 30°C in BHI broth, at 96 hours. MIC of heavy metals for planktonic cells of isolates for cadmium, zinc and lead was 8 mM and assayed for copper and chromium respectively 4 and 1 mM. MBEC of heavy metals for biofilm cells of isolates for cadmium, zinc and lead was 16 mM and assayed for copper and chromium respectively 8 and 4 mM. The results of present study showed biofilm cells of native Rhodococcus isolates were 2 times more resistance to lead, copper, zinc and cadmium than planktonic cells while biofilm cells were 4 times more resistance than planktonic cells to chromium.
Biofilm formation of R.rhodochrous and R.rhodnii and their high resistance to various concentrations of heavy metals especially cadmium show that inoculation of these native Rhodococcus isolates to contaminated agricultural soils with heavy metals, have an effective role for bioremediation.

Background & Aims of the Study: The most important compounds in hospital wastewater are antibiotics, disinfectants, anesthetics, radioactive elements, static cytotoxic agents, other chemicals and hazardous materials that caused to be different domestic sewage. The purpose of this study was the evaluation of performance of extended aeration biological system in pollutants removal from Razi Hospital wastewater treatment plant (WTP), Ahvaz city of Iran.
The hospital wastewater disposal and treatment in Razi hospital have been studied in this cross-sectional research. Total of 12 samples from effluents of wastewater treatment plants were collected and tested for pH, Biological Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Total Suspended Solid (TSS) and Total Coliform (TC). EPA standard method was used for conducted trials. Finally, the relationship between results at different months and stations was done, using SPSS18 and descriptive statistics.
Results shown that parameters average in effluent was pH=7.46¡ BOD= 48.58 mg/l, COD=99.25 mg/l, TSS=54 mg/l, NH3=5.65mg/l, Turbidity=29.57 NTU. Also total coliform and fecal coliform of effluent were 46.19 MPN/100 ml and 36.65 MPN/100 ml, respectively. According to results, the percentage of BOD, COD, TSS and TC removal in WTP were 85.21, 82.46, 86 and 90.15.
Based on these findings, Razi hospital effluent wastewater treatment plant was mitted at Iran environmental standards for discharge to recipient wasters. Based on the result of our study, Extended Aeration Biological System is a comparatively suitable process for BOD, COD, TSS and TC removal from hospital wastewater.

Background & Aims of the Study: Identification of hazards is one of the first goals of risk analysis. Failure mode and effect analysis method (FMEA) is universally defined as efficient procedures for finding potential failures aimed to remove or decrease the risk which is related to them. This study aimed to investigate the effect of control measures on reduction of risk events in an edible oil factory in Tehran.
This cross-sectional study was conducted in an edible oil factory in Tehran, Iran. For this, a four-member team of safety engineer experts was formed. Some factory units were selected randomly. After that, in all units, probability, severity and detection probability of hazards in all processes and tasks were assessed based on FMEA method. Regarding to the RPN, some control measures were taken to reduce the risk of events. After 9 months, risk assessment was repeated; primary and secondary RPNs were compared with each other to investigate the effect of interventions.
The results showed that highest and lowest probability of hazard were related to installation and can production unit, respectively. The highest and lowest severity of hazard were related to tool and can production unit, respectively. There was a significant difference between the probability of hazard in can-making and filling units, before and after the interventions. There was a significant difference between the severity of hazard in can-making, filling and neutralization units, before and after the interventions. As well, total probability, severity and RPN had a significant difference in all parts of the factory before and after the interventions.
According to the results of this study and the overall risk reduction caused by interventional measures, it can be concluded that, FMEA is a successful method for identifying hazards and risk control measures.

Background & Aims of the Study: Musculoskeletal disorder (MSD) is one of the most serious consequences of improper posture or work-related strain with Symptoms of pain in one or more regions of the body. Repeated long-term work-related load can be considered as the main cause of ULWMSDs. This study was aimed to do ergonomic assessment in a manufacturing company in Kashan city using ART as a new method (this method was established in 2007) in 2014-2015.
In a cross-sectional study, total workers of a manufacturing factory (240), by the randomized sampling procedure were selected. Demographic and work related data were collected into the check list. Data about musculoskeletal disorders were provided from body map questionnaire (BM) and ART method worksheets. Statistical analyses were used to data analysis by SPSS V20.
Data analysis from BM illustrated that %85.8 of workers claimed work related pain in one of their body limbs at least. There was a significant relation between pain position numbers and gender of workers (p Despite participants had low mean of age and work history, the prevalence of musculoskeletal disorders was high and the relationship between the ART score and the prevalence rates of disorders showed that the risk of these disorders was higher in people with musculoskeletal disorders than people without these disorders. The findings from this study suggest that management needs to identify, assess and control the most relevant WMSD risk factors for a particular job, accurately.

Background & Aims of the Study: Iranian food diet contains nutrients and herbal spices. From the most important challenges in relation to these spices is their pollution with various heavy metals. Thus, this study aims to characterize the amounts of heavy metals in collected spices from Hamedan city of Iran during 2015-2016.
180 samples of commercially accessible vegetal spices were collected from local stores all over the Hamedan city. The samples were weighted and dried in an electrical oven at 105 ±1 °C for 24 h. Then, samples were grounded to powder by a grinder. Afterwards, the samples were digested by adding 4 ml and 1 ml of concentrated nitric acid and hydrogen peroxide, respectively. After filtration of samples, flamed atomic absorption used for detection of Zinc, Copper, Iron, Nickel, Manganese, Cadmium and Lead concentrations. For the statistical analysis of the results, SPSS version 21 was used. For examining data normality, Kolmogorov-Smirnov test; to compare the mean concentration of elements between spice samples from Tukey test and in order to investigate the correlation between the average concentrations of the heavy metals in the samples, Pearson correlation test were used. Comparing mean concentration of elements with standard values was conducted, using one-sample t-test.
The mean concentrations of Cadmium as a toxic trace element were low in all samples and no risk threatens consumers. But, lead content in dried mint (6.04±0.85mg/kg) was high compared to the standard values. This trend was followed by cinnamon (4.88±1.32), turmeric (2.05±0.63), black pepper (1.51±0.63), sumac (1.17±1.08) and red pepper (0.72±0.85).
Lead in dried mint exceeded the standard value whose reason can be the increase of population, mining, industrialization, transportation and usage of chemical fertilizers, leading to the spread of environmental pollution. Thus, more serious health cares and regular periodic supervisions on food spices regarding pollution with this element seem necessary.

Background & Aims of the Study: One of the most important pollutants in drinking water, air and soils is heavy metals. It is very harmful for humans and other live organisms. The purpose of this study was the usage of a co-composting process for removal of heavy metals from municipal solid waste and sewage sludge.
This experimental study was a conducted sewage sludge and municipal solid waste. For collection of samples from urban solid waste composting and wastewater treatment plant, a 200 mL polyethylene bottles was used, samples after acidification were stored in a dark place at 4°C temperature until the metals analysis the heavy metals values remaining in the samples was measured by graphite furnace absorption spectrometer method (Varian, SpectrAA 240, Australia). In this study, we used SPSS version 16 for data processing; and they were also analyzed by descriptive statistics.
Result of this study showed that values of C/N in the first, second and third stage compost were 31.7, 27.3 and 41.8, respectively. Based on the result of this study the value of removal of Cd with 9.8 mg kg-1 in first stage and Cr, Cu and Zn with 89, 21 and 87.6 mg kg-1 in third stage were highest treatment.
Our results show that co-composting process between many treatment processes having to be cost effective for heavy metal removal from solid waste and wastewater treatment.

Background & Aims of the Study: One of the most carcinogenic and toxic pollutants is p-Nitro Cresol. In this study, the degradation and mineralization of p-Nitro Cresol in aqueous solution were investigated by Fenton process in a batch reactor.
This study is an experimental research on a laboratory scale. The study executed on synthetic wastewater having p-Nitro Cresol. The impact of operational factors such as pH, initial concentration of hydrogen peroxide and Ferrous ions was also investigated. The Box–Behnken design (BBD) of experiments and the response surface methodology (RSM) were employed to study the effects of three independent variables in the response function to acquire the optimal conditions.
The ANOVA (analysis of variance) tests were executed to conclude the importance of the effects of independent variables on the response function. The ANOVA displayed a high determination coefficient value (R2=92.88, R2adj=96.85 and R2pred=82.06) and satisfactory prediction second-order regression model. Different amounts of variables were optimized for the removal of p-Nitro Cresol in Fenton process. The optimum conditions predicted by the model were as follows: the (Fe2)=0.77 mM, pH at 2.95, and (H2O2)=19.8 mM.
The results exhibited that at the predicted optimum conditions and after 45 min of reaction, the removal of p-Nitro Cresol and Chemical oxygen demand (COD) were 97.4 and 48.0%, respectively. The Fenton process was powerful in the removal of p-Nitro Cresol, but it can remove the COD to some extent.

Background & Aims of the Study: Malaria is an infectious disease by fever, chills and anemia; and splenomegaly genus Plasmodium parasite is the agent of it. One of the easiest and least expensive methods for preventionof this disease is removing the vector that usually has been done by insecticides and chemical pesticides, but now days due to the harmful effects of toxic chemicals, it is currently trying to use organic toxic and plant compounds in order to combat the pests. So, in this study Hyoscyamus niger was used in order to destroy the larvae of this insect and positive results were compared these plants together.
Hyoscyamus niger was collected and dried to extract by methanol in a rotary evaporator. Mosquito larvae were collected from stagnant water pits and ponds around the Birjand city, South Khorasan of Iran in order to apply the relevant tests identity and isolated Anopheles spp mosquito larvae.
Hyoscyamus niger positive effect was destroying on the Anopheles spp larvae and between obtained results, the most powerful extract for destroying the mosquitoes Anopheles spp larvae was the flower extract of henbane (LC50=0.07) and the weakest extract was the extract of the root of henbane (LC50=0.78).
According to the results it is recommended the flower extract of henbane as a toxic, organic and natural compound to fight the larvae of Anopheles spp mosquito larvae which used in the other parts of these plants more stronger and more effective.