شاپا: 2322-5130

ABSTRACT
Background and aims: Dairy industry is one of the important sources of environmental pollution. The present
study set out to investigate the removal percentages of COD and turbidity, as well as changes in the effluent pH by
Electro-Coagulation Flotation (ECF) process during the treatment of dairy effluents.
Materials and methods: Electrochemical coagulation process was applied to treatment of pre-treated highly loaded
real wastewater of a factory producing dairy products in Damavand-Tehran. The experiments were carried out
in an electrochemical cylinder-shaped reactor made of steel (cathode electrode) and aluminum (anode electrode)
connected to each other in a Bipolar-serial (BP-S) way. The influence of initial pH, current intensity, electrolysis
time, and initial electrolyte (NaCl) concentration on the performance of ECF was explored. Owing to the nature of
the study, there were not ethical issues.
Results: The findings revealed that the bulk liquid pH, current intensity and electrolysis time had a considerable
influence on the performance of the reactor. The obtained optimal values were 9, 3 A, and 60 min, respectively. Under
optimal condition, the efficiency of COD and turbidity removal were estimated at 70.9% and 99.08%, respectively.
It was also found that the reactor effluent pH increased by 1.6 units. Moreover, electrical conductivity of solution
did not affect the pollutant removal efficiency in this study. Sludge volume index (SVI) was further estimated to be
89.01 ml/g.
Conclusions: The results of the present study indicate that the ECF coupled process can be regarded as an
environment-friendly method in the pre-treatment of dairy effluents. In addition, considering the increase of BOD5/
COD ratio from 0.41 (raw wastewater) to 0.79 (effluent), electrochemical treatment was conceived to enhance the
biodegradability for a biological post-treatment.
Keywords: Dairy wastewater, electro-coagulation flotation, COD, turbidity

Background and aims: Assessment of oral health status is considered as one of the main criteria for evaluating the public health. Knowledge and attitude towards oral health behavior, especially brushing and gender difference
are factors influencing oral health. This study was aimed to compare tooth brushing related knowledge, attitude and health behavior as well as …. (DMFT) among girl and boy students in elementary schools in district 4 of Tehran in
2015.
Method: The present cross-sectional (descriptive and analytical) study was carried out among 408 girl and boy elementary students from six randomly selected schools in district 4 of Tehran, Iran. Two-stage cluster sampling was selected and employed. A valid and reliable researcher-… questionnaire was used for this study. Dental visits were
performed on the basis of DMFT index and all students were assured of information confidentiality. The data were analyzed using SPSS (version 16) software.
Results: In the current study, comparing female students with males showed that the mean scores of brushing knowledge, attitude and health behavior in girls was higher than boys and the difference was statistically significant (p=0.001). However, the observed mean DMFT difference between the girls and boys in this study was not significant (p>0.05). Furthermore, a strong and statistically significant relationship was noticed between frequency of brushing and DMFT in both sexes (p<0.05).
Conclusion: Mean scores of knowledge, attitude and behavior in both sexes were fairly good and also better in female students than males. It was further found that boys and girls in our study can be, respectively, classified as low and very low mean DMFT groups based on World Health Organization classification. Therefore, appropriate educational interventions with more focus on the vulnerable group of boys are highly advocated in order to improve their knowledge and attitude.
Key Words: Knowledge, Attitude, DMFT, Health behavior brushing

Non-carcinogenic risk assessment of occupational exposure to hexavalent chromium in two

Zohreh Fazli, Rezvan Zendedel, Davod Panahi, Mohsen Omidi, Javad Sajedi far, Nima firouzeh

, , 25 December 2016

Background and aims: There are increasing evidences for the toxicity of hexavalent chromium compounds. In the present research, occupational exposure to hexavalent chromium in the electroplating industry was studied. The corresponding non-carcinogenic risk was also assessed in two types of chrome electroplating workers.

Materials and methods: Occupational exposure to hexavalent chromium was evaluated in eighteen decorative and hard chromium electroplating workshops in Tehran, Iran. About 35 hard chromium electroplaters and 30 workers from decorative chrome electroplating workshops were studied. NIOSH 7600 was used to assess occupational exposure to hexavalent chromium. Non-carcinogenic risk assessment of hexavalent chromium was performed according to EPA reference dose. Ethical issues such as confidentiality of information and the announcement of results to the participants were all considered in all stages of research.

Results: The median hexavalent chromium concentration in studied workshops was 0.029 mg/m3, with the

maximum occupational exposure of 0.096 mg/m3 in A7 related to hard chrome electroplating and the minimum level of 0.019 mg/m3 in B6 from decorative chrome electroplating workshops. The results of this study further showed that exposure to hexavalent chromium in the hard chromium electro plating workshops was significantly (p≤0.0001) higher than decorative chrome plating workshops. Non-carcinogenic risk of hard chrome electroplaters was 6 times higher than decorative chrome electroplating workers.

Conclusion: Airborne exposure to hexavalent chromium in the studied chrome electroplating workshops is lower

than limit standard of occupational exposure, but non-carcinogenic risk is higher than acceptable level.

Keywords: Chromium VI, Chrome electroplating, Non-carcinogenic risk

Zinc absorption in two-year old Poplar seedlings (Populus deltoids) in the environment

Seyed armin hashemi, mahnaz zargham inanlou, Amir Hossein Firouzan

, , 25 December 2016

Background and Aims: Phytoremediation is the use of green plants to reduce contaminant levels such as heavy metals in the environment. Some plants can uptake and store (accumulate) environmental contaminants within their tissue and organs. Due to their sustainability in the environment, heavy metals are of particular significance. This study was, therefore, conducted to evaluate the phytoremediation potential of zinc by Populus deltoids.

Materials and Methods: Biennial seedlings of populous deltoids were provided from plantations with arrangements made well in advance with the directors of the Department of Natural Resources. Zinc chloride solutions (0, 10, 20 and 40 mg /L) were prepared, added into the soil and the seedlings were thereafter placed in pots. The seedlings were grown for three months exposing to various zinc concentrations. Seedlings aerial organs (stems and leaves) and roots as well as the soil were sampled and analyzed using atomic absorption spectrometry. Analysis of variance (ANOVA) followed by Duncan’s multiple comparisons (P < 0.05) was performed to test the significance of treatment effects.

Results: The highest level of Zn in aerial organs, root and the soil structure of Populous deltoids was 142.86, 85.94, 12.002 mg/kg, respectively. Similarly, the corresponding lowest level of Zn was 44.61, 21.20, and 0.124 mg/kg. The high-zinc (40 mg/L) treated plants showed the lowest levels of 4.14 and 1.03 g/L in aerial organs and root dry weights, respectively. The maximum values of 20.61 and 3.066 were also respectively determined at control experiments.

Conclusions: The results suggest that Populous deltoids is an appropriate alternative for phytoremediation of zincpolluted soils.

Treatment of municipal solid wastes leachate using electrocoagulation

Mahdi Sadeghi, Maham Tadrisi, Abotaleb Bay, Yousef Dadban Shahamat

, , 25 December 2016

Background and aims: Considering the grate polluting potential of landfill leachate and in order to prevent environmental pollution, the present study set out with the aim of assessing the efficiency of electrocoagulation process for organics, nitrogen, phosphorous and turbidity removal from landfill leachate.

Materials and methods: In the present descriptive-analytical experimental study, the sample of leachate was supplied from Aq-Qala Landfill and compost center in Gorgan. Landfill leachate treatment was consequently performed by an electrochemical reactor. The paper studies the factors affecting the efficiency of reactor, such as electrolysis time (20, 40, and 60 min), pH of solution (3, 7 and 9), and the electric potential difference (20, 40 and 60 V). All studied parameters were determined according to standard methods. Because of the nature of the project, there were not ethical issues in this study.

Results: The highest removal of turbidity, COD, nitrate, and phosphorus in raw leachate were 59.14, 44.33, 40.81and 48.86, respectively, achieved at 60 V, neutral pH (6.5-6.9) and operating time of 60 min. The corresponding removal percentages for treatment plant effluent electrocoagulation were 88.9, 80.5, 59.16 and 62.35, respectively.

Conclusions: The results show that electrocoagulation process can be applied to leachate pre-treatment in order to remove organic matter, turbidity, nutrients, and organics loading reduction and consequently to enhance the biodegradability of leachate. Thus, the process can be considered as an effective alternative in the pre-treatment of wastewater in order to prevent environmental pollution and protection of water resources.

Keywords: Leachate, nitrate, phosphorous, electrocoagulation, chemical oxygen demand

Background and Aims: Obesity is one of the most common nutritional problems. Understanding the prevalence of overweight and obesity in women is essential to planning and prioritizing of health problems. The current study aimed to broaden our understanding of the prevalence and related factors of overweight and obesity in the women at ages of pregnancy in Rasht, Iran, in 2015.

Materials and Methods: The present cross-sectional study was designed to investigate the prevalence of overweight and obesity in women aged 20 to 50 years living in Rasht. The multiple-stage sampling method was used to recruit the participants. All participants provided informed consent before entering the study. Body mass indexes of >30 kg/m2 and >25 kg/m2 were considered obese and overweight, respectively. The collected data were analyzed by descriptive statistics, chi-square test and correlation coefficients.

Results: The mean age of participants in the study was 19.28 (SD= 6.99). About 2.9% and 24.8% of study participants were obese and overweight, respectively. Also, the relationship between prevalence of overweight, mobility status, age and income was statistically significant.

Conclusion: Our study found that overweight and obesity is a major public health problem among women living in the region and, thus, more attention should be given to reproductive-aged women with increased obesity-related measures.

Keywords: Prevalence, Overweight, Obesity, Women, Rasht