Correlation between drinking water fluoride and TSH hormone by ANNs and ANFIS

Background

Artificial neural networks (ANNs) and adaptive neural-fuzzy Inference system (ANFIS) are the best solutions to finding the correlation between some water parameters and human hormones. The correlation between thyroid stimulating hormone (TSH) and drinking water fluoride studied by ANN_S and ANFIS models in Yazd city.

Method

In this study, eighty people with thyroid gland disorder and 213 healthy people invited. Their thyroid hormones and fluoride drinking water analyzed.

Results

The result of ANFIS showed R² = 0.81 for test and R² = 0.85 for train in all cases and controls data. This results were R² = 0.73 and R² = 0.81 for ANNs respectively.

Conclusion

This models can be used as an alternative for show correlation between Drinking Water Fluoride and TSH Hormone and R² = 0.85 gained from ANFIS was the best.

Arsenic exposure to breast-fed infants: contaminated breastfeeding in the first month of birth

Humans are exposed to heavy metals through ingestion, inhalation, and dermal absorption. Exposure to these chemicals may be possible during lactation. Although breastfeeding has import benefits of physical growth and development of breastfed infants, it may be a source of exposure to toxicants. The present study was conducted to determine infant exposure to the arsenic via breastfeeding. The milk samples were collected from the 150 volunteering mothers three times during the first month of lactation after delivery. The average arsenic concentration in breast milk samples was measured by atomic absorption spectrometer (AAS). The demographic parameters of lactating mothers were collected by a questionnaire and were analyzed using SPSS 18 software. Arsenic was not detectable in 71 of 150 samples (47.3%). The highest arsenic concentration was 3.73 μg/L, and overall mean of arsenic concentration was 0.87 ± 0.66 μg/L. The daily infant intake of arsenic ranged in the 0.01-0.17 μg/kg of body weight, which is below the limit of daily permissible intake for adults. Our results showed the need to strengthen national food safety programs and to further promote avoidance of unhealthy foods consuming during pregnancy. Most of the study samples had detectable levels of arsenic indicate that there was maternal exposure prior to pregnancy, nevertheless, it is recommended that the toxic metal levels should be regularly monitored in biological environments.

Biodegradation and nutrients removal from greywater by an integrated fixed-film activated sludge (IFAS) in different organic loadings rates

In this study, the efficiency of Integrated Fixed-film Activated Sludge (IFAS) system in synthetic greywater treatment and nutrients removal was studied in duration of 105 days according to different Organic Loadings Rates (OLRs). The study was operated in pilot-scale and OLRs of 0.11–1.3 gCOD/L.d. Scanning Electron Microscope (SEM) image showed that the biofilm with a proper thickness was formed on IFAS reactor’s media. The results indicated that the best removal efficiency of BOD₅, COD, and TSS were 85.24, 92.52 and 90.21%, respectively, in an organic loading of 0.44 gCOD/L.d. Then, with the OLR increased, the removal efficiencies of BOD₅, COD, and TSS increased as long as the organic loading reached 0.44 gCOD/L.d. But with the OLR increased more, the removal efficiency of these parameters decreased. The ANOVA statistical test results showed that the mean difference of removal efficiency in organic loadings for BOD₅ (p ≤ 0.001) and COD (p = 0.003) was significant, while it was insignificant for TSS (p = 0.23). The best removal efficiencies of Total Nitrogen (TN) and Total Phosphorus (TP) were 89.60 and 86.67%, respectively, which were obtained at an OLR of 0.44 gCOD/L.d. By increasing OLR up to 0.44 gCOD/L.d, removal efficiencies of TN and TP increased, while the removal efficiency decreased with the OLR increased more, and this difference was statistically significant (p = 0.021). Finally, the results showed that the IFAS system provided a proper efficiency in treatment of the synthetic greywater and it could be used in a full scale.

Ozone-cathode microbial desalination cell; An innovative option to bioelectricity generation and water desalination

Microbial desalination cell (MDC) is a new approach of water desalination methods, which is based on ionic species removal from water in proportion to the electric current generated by bacteria. However, the low current generation and insufficient deionization in this technology have created challenges to improve the process. Here, the performance of MDC using ozone as a new electron acceptor (O₃-MDC) was evaluated versus another operated independently with oxygen (O₂-MDC). Results showed the maximum open-circuit voltages of 628 and 1331 mV for 20 g L^-1 NaCl desalination in O₂-MDC and O₃-MDC, respectively. The O₃-MDC produced a maximum power density of 4.06 W m^-2 (about 11 times higher than O₂-MDC) while at the same time was able to remove about 74% of salt (55.58% in the O₂-MDC). Each cycle of O₂-MDC and O₃-MDC operation lasted about 66 and 94 h, respectively, indicating a more stable current profile in the O₃-MDC. Moreover, sequencing test based on 16S rRNA gene showed that the anode biofilm had more diverse microbial community than anolyte sample. Proteobacteria, Firmicutes and Acidobacteria were from dominant microbial communities in anode biofilm sample. Accordingly, the results revealed that ozone can enhance MDC performance either as a desalination process or as a pre-treatment reactor for downstream desalination processes.

Optimization of photochemical decomposition acetamiprid pesticide from aqueous solutions and effluent toxicity assessment by Pseudomonas aeruginosa BCRC using response surface methodology

Contamination of water resources by acetamiprid pesticide is considered one of the main environmental problems. The aim of this study was the optimization of acetamiprid removal from aqueous solutions by TiO₂/Fe₃O₄/SiO₂ nanocomposite using the response surface methodology (RSM) with toxicity assessment by Pseudomonas aeruginosa BCRC. To obtain the optimum condition for acetamiprid degradation using RSM and central composite design (CCD). The magnetic TiO₂/Fe₃O₄/SiO₂ nanocomposite was synthesized using co-precipitation and sol–gel methods. The surface morphology of the nanocomposite and magnetic properties of the as-synthesized Fe₃O₄ nanoparticles were characterised by scanning electron microscope and vibrating sample magnetometer, respectively. In this study, toxicity assessment tests have been carried out by determining the activity of dehydrogenase enzyme reducing Resazurin (RR) and colony forming unit (CFU) methods. According to CCD, quadratic optimal model with R² = 0.99 was used. By analysis of variance, the most effective values of each factor were determined in each experiment. According to the results, the most optimal conditions for removal efficiency of acetamiprid (pH = 7.5, contact time = 65 min, and dose of nanoparticle 550 mg/L) was obtained at 76.55%. Effect concentration (EC₅₀) for RR and CFU test were 1.950 and 2.050 mg/L, respectively. Based on the results obtained from the model, predicted response values showed high congruence with actual response values. And, the model was suitable for the experiment’s design conditions.

The relationship between environmental exposures and hormonal abnormalities in pregnant women: An epidemiological study in Yazd, Iran

PROBLEM

The process of industrialization and lifestyle changes have gradually exposed human ‎societies to a larger number of environmental risk factors, which may cause hormonal ‎abnormalities and congenital anomalies.

BACKGROUND

The current study aimed to investigate the relationship ‎between environmental factors and hormonal abnormalities among pregnant women in Yazd, ‎Iran.

METHODS

A hundred participants were randomly selected from among a group of pregnant women. According to the screening tests (AFP, free β-‎HCG, uE3, PAPP-A, and inhibin-A) performed at the genome clinic in Yazd in 2016, the risk of Down Syndrome (DS) was sufficiently high in this group of pregnant women from which the participants were selected. A ‎questionnaire was used to collect data on the degree of the participants' exposure to pesticides ‎at home, use of canned and fast foods, and consumption of greenhouse fruits. The collected data were ‎analyzed by One-way ANOVA and Kruskal-Wallis Test.

FINDINGS

The mean of Multiple of Median (MoM) for inhibin-A was significantly higher among pregnant ‎women who often or always used pesticides at home (p=0.047). The mean MoM ‎for free β-HCG was significantly higher among pregnant women who often or always used canned ‎foods (p=0.024). Finally, the mean MoM for uE3 (1.85±1.30) was significantly higher among ‎pregnant women who never consumed greenhouse fruits (p=0.003).

CONCLUSION

It can be concluded that it is possible to reduce environmental exposures affecting hormonal abnormalities among pregnant women by improving nutritional patterns, minimizing the use of pesticides at home, and reducing the intake of canned foods and greenhouse fruits.

Evaluation of removal efficiency of residual diclofenac in aqueous solution by nanocomposite tungsten-carbon using design of experiment

Wastewater containing pharmaceutical residual components must be treated before being discharged to the environment. This study was conducted to investigate the efficiency of tungsten-carbon nanocomposite in diclofenac removal using design of experiment (DOE). The 27 batch adsorption experiments were done by choosing three effective parameters (pH, adsorbent dose, and initial concentration) at three levels. The nanocomposite was prepared by tungsten oxide and activated carbon powder in a ratio of 1 to 4 mass. The remaining concentration of diclofenac was measured by a spectrometer with adding reagents of 2, 2'-bipyridine, and ferric chloride. Analysis of variance (ANOVA) was applied to determine the main and interaction effects. The equilibrium time for removal process was determined as 30 min. It was observed that the pH had the lowest influence on the removal efficiency of diclofenac. Nanocomposite gave a high removal at low concentration of 5.0 mg/L. The maximum removal for an initial concentration of 5.0 mg/L was 88.0% at contact time of 30 min. The results of ANOVA showed that adsorbent mass was among the most effective variables. Using DOE as an efficient method revealed that tungsten-carbon nanocomposite has high efficiency in the removal of residual diclofenac from the aqueous solution.

Application of novel Modified Biological Aerated Filter (MBAF) as a promising post-treatment for water reuse: Modification in configuration and backwashing process

Biological Aerated Filter (BAF) reactors due to their plentiful biomass, high shockability, high efficiency, good filtration, availability and lack of need for large land areas, are enjoying from great importance in advanced wastewater treatment. Therefore, in this study, Polystyrene Coated by Sand (PCS) was produced as a novel media and its application in a modified down-flow BAF structure for advanced wastewater treatment was assessed in two steps. In step one, the backwash effluent did not return to the system, while in step two backwash effluent returned to increase the water reuse efficiency. The backwash process was also studied through three methods of Top Backwashing (TB), Bottom Backwashing (BB), as well as Top and Bottom Backwashing Simultaneously (TBBS). The results showed that return of backwash effluent had no significant effect on the BAF effluent quality. In the second step similar to the first one with slight differences, the residual average concentrations of TSS, BOD₅, and COD at the effluent were about 2.5, 8.2, and 25.5 mg/L, respectively. Additionally, in step two, the mean volume of disposal sludge/volume of treated water (v_ds/v_tw) decreased a large extent to about 0.088%. In other words, the water reuse has increased to more than 99.91%. The backwash time in methods of TB and BB were 65 and 35 min, respectively; however, it decreased in TBBS methods to 25 min. The concentrations of most effluent parameters in this system are in concordance with the 2012 EPA Agriculture Standards, even for irrigation of Non-processed agricultural crops and livestock water consumption.

Human health impact assessment of exposure to particulate matter: an AirQ software modeling

The aim of this study was to assess the health impacts related to particulate matter less than 10 μm (PM₁₀) exposure in the city of Yazd, Iran. For this aim, AirQ 2.2.3 software was used to model relationship between short-term exposure to PM₁₀ and disease cases proposed by the World Health Organization (WHO). The annual mean concentration of PM₁₀ was 97 μg/m³. The maximum concentration value of PM₁₀ was measured during the summer (731 μg/m³). 4.988% (95%CI: 3.381-6.542%) of the total mortality, 7.3% (95%CI; 4.19-10.21%) of cardiovascular mortality, and 10.21% (95%CI; 4.19-14.89%) of respiratory mortality were related to the PM₁₀ concentrations. Consequently, the AirQ software can provide valuable information about the importance of air pollution and the substantial impacts of PM₁₀ on the society for policymakers.

Effect of Organic Loading Rates on biodegradation of linear alkyl benzene sulfonate, oil and grease in greywater by Integrated Fixed-film Activated Sludge (IFAS)

In this study, performance of Integrated Fixed-film Activated Sludge (IFAS) system in treatment of Linear Alkylbenzene Sulfonate (LAS), and oil & grease in synthetic greywater and effect of Organic Loading Rates (OLRs) on removal efficiency within a period of 105 days were investigated. Present study was carried out in a pilot scale under such conditions as temperature of 30 ± 1 °C, dissolved oxygen of 2.32 ± 0.91 mg/l, pH of 8.01 ± 0.95 and OLRs of 0.11-1.3gCOD/L.d. Also, Scanning Electron Microscopy (SEM) images were employed to specify rate of the biofilm formed on the media inside the reactor IFAS. The best removal efficiency for COD, LAS and oil and grease were respectively obtained as 92.52%, 94.24% and 90.07% in OLR 0.44gCOD/L.d. The assessment of loading rate indicated that with increased OLR to 0.44gCOD/L.d, removal efficiency of COD, oil and grease was increased while with increased OLR, removal efficiency was decreased. In doing so, based on the statistical test ANOVA, such a difference between removal efficiencies in diverse OLRs was significant for COD (p = 0.003), oil and grease (p = 0.01). However, in terms of LAS, with increased value of OLR to 0.44gCOD/L.d, the removal efficiency was increased and then with higher OLRs, removal efficiency was slightly decreased that is insignificant (p = 0.35) based on the statistical test ANOVA. The SEM images also showed that the biofilm formed on the media inside IFAS reactor plays a considerable role in adsorption and biodegradation of LAS, and oil & grease in greywater. The linear relation between inlet COD values and rate of removed LAS indicated that the ratio of inlet COD (mg/L) to removed LAS (mg/L) was 0.4. Therefore, use of IFAS system for biodegradation of LAS, oil and grease in greywater can be an applicable option.

A comparative study on capability of different tree species in accumulating heavy metals from soil and ambient air

Heavy metals (HMs) in the urban environment can be bio-accumulated by plant tissues. The aim of this study was to compare fourteen different tree species in terms of their capability to accumulate four airborne and soilborne HMs including; zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd). Samplings were performed during spring, summer, and fall seasons. To compare bioaccumulation ability, bio-concentration factor (BCF), comprehensive bio-concentration index (CBCI), and metal accumulation index (MAI) were applied. Species with the highest accumulation for single metal which shown using BCF did not have the highest CBCI and MAI. Based on CBCI and MAI, Pinus eldarica (7.74), Wistaria sinensis (8.82), Morus alba (8.7), and Nigral morus (27.15) had the highest bioaccumulation capacity of HMs, respectively. Therefore, these species can be used for phytoextraction of HMs pollution and green and buffer zone in the urban.

Evaluation of volcanic pumice stone as media in fixed bed sequence batch reactor for atrazine removal from aquatic environments

Atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) is a component of S-triazine. Its characteristics make it a pollutant of ecosystems and a probable human carcinogen. The present study evaluated volcanic pumice stone as a suitable media for biological growth and biofilm development in a fixed-bed sequencing batch reactor (FBSBR) for atrazine removal from aquatic environments. The FBSBR was fed with synthetic wastewater containing sucrose and atrazine at four hydraulic retention times to assess biodegradation of atrazine by a microbial consortium for removal from aquatic environments. The maximum efficiency for atrazine and soluble chemical oxygen demand removal were 97.9% and 98.9%, respectively. The results of this research showed that the Stover–Kincannon model was a very good fit (R2 > 99%) for loading atrazine onto the FBSBR. Increasing the initial concentration of atrazine increased the removal efficiency. There was no significant inhibition of the mixed aerobic microbial consortia by the atrazine. Atrazine degradation depended on its initial concentration in the wastewater and the amount of atrazine in the influent. Although this system shows good potential for atrazine removal from aqueous environments, that remaining in the effluent does not yet meet international standards. Further research is required to make this system effective for removal of atrazine from the environment.

Health literacy among adults in Yazd, Iran

The purpose of this survey was to assess the health literacy levels and determine the relationship between health literacy with demographic variables and the socioeconomic status Three hundred and eighty adults, 18 years and older, were randomly selected and assessed by the Test of Functional Health Literacy in Adults (TOFHLA) instrument in two sections of reading comprehension and numeracy. The second instrument used to detect the relationship between the demographic variables and socio-economic status and the level of health literacy of the subjects of adults in Yazd district. Three hundred and eighty adults, 18 years and older, were randomly selected and assessed by the Test of Functional Health Literacy in Adults (TOFHLA) instrument in two sections of reading comprehension and numeracy. The second instrument used to detect the relationship between the demographic variables and socio-economic status and the level of health literacy of the subjects. The mean score of a participant's health literacy was 73.33 ± 1.29. Fifty-four percent of the individuals had adequate health literacy and the rest of them had limited health literacy. The mean score of functional health literacy was significantly different by socio-economic status (p0.05) and the years of schooling (P = 0.00). On the basis of linear regression, in this research, the years of schooling (B0.28, p0.01) and marital status (B = 3.08, p0.05) were two predictors of health literacy.

Cadmium removal from aqueous solution by green synthesis iron oxide nanoparticles with tangerine peel extract

Background

The adsorption process by metal oxide nanoparticles has been investigated an effective agent for removing organic and inorganic contaminants from water and wastewater. In this study, iron oxide nanoparticles were synthesized in the presence of tangerine peel extract as adsorbent for cadmium ions removal from contaminated solution. Iron oxide nanoparticles prepared by co-precipitation method and tangerine peel extract was used to prevent accumulation and reduce the diameter of the particles. Effect of various parameters such as contact time, pH, metal concentration and adsorbent dosage was determined on the removal efficiency.

Results

The different concentrations of tangerine peel had an impact on the size of nanoparticles. As, increasing the concentration of tangerine peel extract from 2 to 6 % the average size of synthesized iron oxide nanoparticles decreased 200 nm to 50 nm. The maximum removal of cadmium ions (90 %) occurred at pH of 4 and adsorbent dose of 0.4 g/100 ml. Adsorption of cadmium ions by synthesized iron oxide nanoparticles followed Freundlich adsorption model and pseudo-second-order equation.

Conclusion

The cadmium ions are usually soluble in acidic pH and the maximum removal of cadmium by green synthesis iron oxide nanoparticles was obtained in the pH of 4, so these nanoparticles can be a good adsorbent for the removal of cadmium from wastewater.

Humic acid degradation by the synthesized flower-like Ag/ZnO nanostructure as an efficient photocatalyst

Nano-sized flower-like Ag/ZnO was synthesized by a simple method using zinc acetate and silver acetate under hydrothermal condition. Powder X-ray diffraction (PXRD) and transmission electron microscopy (TEM) were used to characterize the structure and morphology of the synthesized powder. Nano flower-like Ag/ZnO was used as a photocatalyst for degradation of humic acid in aqueous solution. The disappearance of HA was analyzed by measuring the absorbance of sample at special wavelength (254 nm). The effects of various parameters such as amount of photocatalyst, pH, initial humic acid concentration and irradiation time on degradation rate were systematically investigated. Photodegradation efficiency was small when the photolysis was carried out in the absence of Ag/ZnO and it was also negligible in the absence of light. Approximately 70% of humic acid (50 mg/L) has been eliminated after 40 minutes in the presences of catalyst (catalyst dose o.6 g/L and pH =7) and UVA irradiation. While, 100% of humic acid has been eliminated with solar irradiation.

Assessment of sick building syndrome and its associating factors among nurses in the educational hospitals of Shahid Sadoughi University of Medical Sciences, Yazd, Iran

Background:

Sick Building Syndrome is a diseases associated with indoor air quality accompanied with symptoms such as headache, dizziness, nausea, coughing and sneezing, irritation of eyes, throat and nose mucous membrane, and skin itching and inflammation. The purpose of this study was to investigate the symptoms of the syndrome and its related factors among nurses in teaching hospitals of Shahid Sadoughi University of Medical Sciences, Yazd, Iran.

Methods:

The study was conducted amongst nurses of three teaching hospitals of Shahid Sadoughi University of Medical Sciences, in Yazd. In this study the MM040EA questionnaire of sick building syndrome and indoor air quality was used and data extracted from the questionnaires were analyzed using the chi-square test and t-test.

Results:

The prevalence of sick building syndrome was 86.4%. The prevalence of the syndrome was in no association with age, gender, employment history and type of shift work. The most common symptoms reported by nurses included headache, fatigue and dry hands. Lack of sense of airflow, unpleasant odor in workplace (P<0.05), and also the amount of workload (P<0.001) were in relation with sick building syndrome.

Conclusion:

The high prevalence of sick building syndrome symptoms in the nursing environment was associated with factors of unpleasant odor and high workload of environment. So improvement of environmental conditions such as increasing the efficiency of the HVAC system, increasing fresh air flow in the sector, reducing the nurses workload as well as enhancing the quality of working life, will motivate the nurses and increase productivity in the workplace.

Indicator pathogens, organic matter and LAS detergent removal from wastewater by constructed subsurface wetlands

BACKGROUND

Constructed wetland is one of the natural methods of municipal and industrial wastewater treatments with low initial costs for construction and operation as well as easy maintenance. The main objective of this study is to determine the values of indicator bacteria removal, organic matter, TSS, ammonia and nitrate affecting the wetland removal efficiency.

RESULTS

The average concentration of E. coli and total coliform in the input is 1.127 × 1014 and 4.41 × 1014 MPN/100 mL that reached 5.03 × 1012 and 1.13 × 1014 MPN/100 mL by reducing 95.5% and 74.4% in wetland 2. Fecal streptococcus reached from the average 5.88 × 1014 in raw wastewater to 9.69 × 1012 in the output of wetland 2. Wetland 2 could reduce 1.5 logarithmic units of E. coli. The removal efficiency of TSS for the wetlands is 68.87%, 71.4%, 57.3%, and 66% respectively.

CONCLUSIONS

The overall results show that wetlands in which herbs were planted had a high removal efficiency about the indicator pathogens, organic matter, LAS detergent in comparison to a control wetland (without canes) and could improve physicochemical parameters (DO, ammonia, nitrate, electrical conductivity, and pH) of wastewater.

Comparison between Ag (I) and Ni (II) removal from synthetic nuclear power plant coolant water by iron oxide nanoparticles

The impact of effective parameters such as iron oxide nanoparticles dosage, contact time and solution pH was optimized for removal of Ag(I) and Ni(II) in the nuclear cooling system and the best conditions were compared. Nearly complete removal (97%) of Ni(II) and Ag(I) were obtained at adsorbent dosage of 40 and 20 g/L, respectively. Experiments showed that 4 hours was a good choice as optimum contact time for two ions removal. The effective parameter was pH, so that maximum removal efficiency was obtained for Ag(I) in acidic pH=3 and for Ni(II) in basic pH=10. It seems that removal of Ag(I) was controlled by adsorption-reduction mechanism, but Ni(II) could place only adsorption. Langmuir and Freundlich model was more suitable for nickel and silver removal by this adsorbent, respectively. Ag(I) and Ni(II) removal efficiency trend by this adsorbent is similar at periods but different in the concentrations, pHs and equilibrium model. The obtained results were very promising, as both Ag(I) and Ni(II) were effectively removed from synthetic wastewater and there was a possibility to remove Ag(I) very fast. Hence, the idea of using nanoparticles for application of metal ions removal from wastewaters seems to be very efficient and quite promising.

Removal of cadmium (II) from simulated wastewater by ion flotation technique

A separation technique which has recently received a sharp increase in research activities is “ion flotation”. This technique has four important advantages for treating wastewaters: low energy consumption, small space requirements, small volume of sludge and acting selectively. The present study aims to optimize parameters of ion flotation for cadmium removal in simulated wastewater at laboratory scale. It was obtained on the reaction between Cd²⁺ and sodium dodecylesulfate (SDS) collector followed by flotation with ethanol as frother. Test solution was prepared by combining the required amount of cadmium ion, SDS and necessary frother or sodium sulfate solution. All experiments were carried out in a flotation column at laboratory temperature (27°C), adjusted pH = 4 and 120 minutes. The different parameters (namely: flow rate, cadmium, SDS and frother concentrations and ionic strength) influencing the flotation process were examined. The best removal efficiency obtained at a collector-metal ratio of 3:1 in 60 min with flow rate of 150 mL/min was 84%. The maximum cadmium removal was 92.1% where ethanol was introduced at a concentration 0.4% to flotation column with above conditions. The obtained results were promising, as both cadmium and collector were effectively removed from wastewater. Hence, the application of ion flotation for metal ions removal from effluents seems to be efficient.

The study of leachate treatment by using three advanced oxidation process based wet air oxidation

Wet air oxidation is regarded as appropriate options for wastewater treatment with average organic compounds. The general purpose of this research is to determine the efficiency of three wet air oxidation methods, wet oxidation with hydrogen peroxide and absorption with activated carbon in removing organic matter and nitrogenous compounds from Isfahan's urban leachate. A leachate sample with the volume of 1.5 liters entered into a steel reactor with the volume of three liters and was put under a 10-bar pressure, at temperatures of 100, 200, and 300° as well as three retention times of 30, 60, and 90 minutes. The sample was placed at 18 stages of leachate storage ponds in Isfahan Compost Plant with the volume of 20 liters, using three WPO, WAO methods and a combination of WAO/GAC for leachate pre-treatment. Thirty percent of pure oxygen and hydrogen peroxide were applied as oxidation agents. The COD removal efficiency in WAO method is 7.8-33.3%, in BOD is 14.7-50.6%, the maximum removal percentage (efficiency) for NH4-N is 53.3% and for NO3-N is 56.4-73.9%. The removal efficiency of COD and BOD5 is 4.6%-34 and 24%-50 respectively in WPO method. Adding GAC to the reactor, the removal efficiency of all parameters was improved. The maximum removal efficiency was increased 48% for COD, 31%-43.6 for BOD5 by a combinational method, and the ratio of BOD5/COD was also increased to 90%. In this paper, WAO and WPO process was used for Leachate pre-treatment and WAO/GAC combinational process was applied for improving the organic matter removal and leachate treatment; it was also determined that the recent process is much more efficient in removing resistant organic matter.

SELF-EFFICACY AND HEALTH PROMOTION BEHAVIORS OF OLDER ADULTS IN IRAN

Increasing healthy behaviors is the major challenge facing health professionals and populations globally. The purpose of this study was to ascertain if a relationship exists between selfefficacy and health promotion behaviors in a sample of older Iranian adults. The organizing framework for the study was Pender's revised Health Promotion Model (Pender, 1996). The study participants were 102 community-dwelling old people residing in Yazd district. The results supported Pender's Health Promotion Model in which self-efficacy accounted for 58% of variance in health promotion behaviors. Health promotion behaviors were found to be correlated with level of education. Additionally, there were associations between self-efficacy and gender, marital status, and level of education. It was concluded that interventions aimed at improving self-efficacy may improve health promotion behaviors of older adults.