فصلنامه سلامت و محیط زیست
سال سوم شماره 3 (پیاپی 9، پاییز 1389)

Backgrounds and Volatile organic compounds (VOCs) are one of the common groups of contaminants encountered in the industrial activities, emitted through air stream into the atmosphere. To prevent the human and environmental health from the adverse effects of VOCs, air streams containing VOCs need to be treated before discharging to environment. This study was aimed at investigating the catalytic ozonation process for removing xylene from a contaminated air stream. In the present work, a bench scale experimental setup was constructed and used for catalytic ozonation of xylene. The performance of catalytic ozonation process was compared with that of single adsorption and ozonation in removal of several concentration of xylene under the similar experimental conditions. The results indicated that the efficiency of catalytic ozonation was higher than that of single adsorption and ozonation in removal of xylene. The emerging time and elimination capacity of xylene for inlet concentration of 300 ppm was 1.4 and 5.8 times of those in adsorption system. The activated carbon acted as catalyst in the presence of ozone and thus attaining the synergistic effect for xylene degradation. catalytic ozonation process is an efficient technique the treatment of air streams containing high concentrations of xylene. The adsorption systems can also be simply retrofitted to catalytic ozonation process and thereby improving their performance for treating VOCs.

Backgrounds and In arid and semi-arid regions of the world, urban runoff as a source of water restoration and is considered valuable. Wastewater treatment, while preserving the environment, it can be considered as water source. The aim of this study to evaluate the possibility of using powder grain Peregrina in wastewater treatment in comparing with Alum and PloyAluminum Chloride (PAC). Flocculation and coagulation tests were done by Jar test. Wastewater quality parameters were measured according to standard method. Studies have been showed that in optimum Peregrina concentration, efficiency of turbidity reduction, total hardness, calcium hardness, magnesium hardness, total E. Coli are 95.11, 38, 55.5, 46.6, 97 and 97 percent respectively. It is noted that turbidity reducing directly related with coli form reduction. As, with increasing turbidity reduction, coliform reduction is increased. The most reduction of E. coli with combination of Alum, Ploy Aluminum Chloride and Peregrina was 100 percent. In optimum concentration of Alum, Ploy Aluminum Chloride and Peregrina, the quality of treated wastewater would be in the range of environmental standards. Therefore, treated wastewater can be entering to surface water and reuse as irrigation water. The results derived from this study showed that the treated wastewater can be use in a variety of irrigation except sprinkler irrigation due to burn the leaves of plants. (high electrical conductivity).Also, the low cost of seed Peregrina and good performance in the refining operations, it is suggested that Peregrina as a replacement for poly aluminum chloride and an alum to be used for wastewater treatment.

Backgrounds and Industrial wastewater included the heavy metal is one of the important sources of environmental pollution. Hexavalent chromiumand divalent nickel are founded in plating wastewater which is harmful for human health and environment. Therefore, the purpose of this research is investigation of photocatalytic removal of hexavalent chromium and divalent nickel from aqueous solution using UV/TiO2 process in a batch system.Materials and At first, reactor was designed. Then, optimumdosage of TiO2 was obtained equal to 1 g/L, with variation TiO2 dosage at constant pH and initial concentrations of hexavalent chromium and divalent nickel. The effect of pH, contact time and initial concentration of hexavalent chromium was studied at the constant amount of TiO2 (1gr/L). The result showed that photocatalytic removal efficiency increased with increasing reaction time and TiO2 dosage. In addition, it was found that removal efficiency of hexavalent chromium was decreased by increasing initial chromium concentration and pH. But, photocatalytic removal efficiency of nickel ion was increased and decreased by increasing of pH and initial nickel concentration, respectively. The results showed that UV/TiO2 was an effective method in removal of hexavalent chromium and divalent nickel from aqueous solutions

Backgrounds and Due to copper and zinc elements toxicity, a greatly attention to removal of those in order to reduce environmental pollution exist. This experiment was conducted to investigate the study of the effect of gravity single layer rapid sand filter on heavy metals (zinc and copper) removal efficiency in aquatic condition in different phosphate concentration. this study applied a gravity single layer rapid sand filter with silica sand media. Experiments conducted for all of the states of Cooper and Zinc concentration in 25, 75, 125 and 175 ppm at different phosphate concentration present by varied discharge. Each state of Solutions pumped on top of the bed and discharge adjusted. Samples taken fromeffluent then acidified immediately with nitric acid. Metals concentration perused by atomic emission spectrometer with ICP source. Collected data analyzed by SPSS software. Founds from this study shown that maximum removal efficiency for copper and zinc was 98.89%and 78.60%respectively effect of discharge,metal concentration and phosphate concentration factors in removal efficiency of zinc and cooper, discharge and phosphate concentration bilateral effect on cooper removal efficiency, phosphate concentration andmetal concentration bilateral on zinc removal efficiency, are significant in 1%. In addition, phosphate concentration and discharge bilateral effect, metal concentration and discharge bilateral effect are significant on zinc removal efficiency in 5%. Finally, bilateral effects of discharge and metal concentration also metal concentration and phosphate concentration have not significant effect on cooper removal efficiency. Gravity single layer of rapid sandy filter with silica sand media in order to cooper removal in low concentration can be used successfully. This method in high concentration of cooper and also different concentration of zinc had not successful result; but in this condition, may be use of a series of filter with more depth

Backgrounds and Geological situation and/or anthropogenic contamination contain an increased concentration of ions such as hexavalent chromium as well as some other dissolved components such as sulfate in the upper of the establishedMCLs (50µg/L). In this paper، simultaneous removal of Cr (VI) and sulfate from water was investigated using nanofiltration as a promising method for reaching drinking water standards. For varying pressure، pH، anion and cation solution effect، Sulfate and Cr (VI) concentration which have chosen were levels found in drinking water sources (Cr=0. 1- 0. 5mg/L) and (SO4-2= 100-800mg/L). Experiments were performed using NaCl، Na2SO4،K2 Cr2O7and anhydrous CrCl3. 6H2O which prepared with de mineralized water on procedure detailed in standard methods. All salts were purchased from Merck Corporation with purity over 99''. The results for hexavalent chromium experiments showed that when the concentration decreases، the chromate anions were given a better retention to 4 bars (96''). But when the concentration increases، concentration polarization led to increased removal of Cr (VI) (98''). For Cr (III) the influences of the ionic strength as well as the concentrations were strongly dependant on rejection but operating pressure were found weak. In addition، with increasing total dissolved solids، perfect rejection of chromium was seen. The effect of pH showed that better retention was obtained at natural and basic pH. This study indicates that the nature of anions and cations، driven pressure and pH have significant effect on nano filtration operation. Research findings show that it seems nano filtration is a very good promising method of simultaneous removal of Cr (VI) and sulfate from water.

Backgrounds and There have been always concerns regarding to consumption of aquatic products، particularly fish، due to the possibility of heavy metals bioaccumulation in aquatic creatures organs، throughout the world. Aresearch project was carried out to assess the level of concentrated total mercury in different tissues of Silver carp as the most consumed fish from Sanandaj Ghesglagh reservoir in the region. Materials and Twenty four silver carp were captured randomly during July to December 2009. Prior measuring mercury concentrations in white muscle، red muscle and liver tissues by AdvancedMercuryAnalyzer (Model; Leco، 254AMA) on the dry weight basis، biometry procedure was done. Mean accumulated mercury in white muscle، red muscle and liver tissues were 367 (S. E. ± 26. 43)، 311 (S. E. ± 32. 22) and 251 (S. E. ± 28. 70) ng gr -1 on the dry weight basis، respectively. Pair comparisons between the level of concentrated mercury in all tissues، except white muscle tissues (F5، 18 = 1. 52، P = 0. 2332) showed a significant difference (P < 0. 05). The level of accumulated mercury in muscle and liver tissues of all samples weighted above 850 grams were higher than the established limits by WHO، FAO and EPA. Our results emphasis that the consumption of silver carp from Sanandaj Gheshlagh Reservoir might place the health of all those peoples who live in the region at risk.

Backgrounds and Arsenic is one of the most toxic and dangerous elements in drinking water that with increase in its application in agriculture، development of applications in agriculture، livestock، medicine، industry and other cases its entry to water resources and environment is much easier. Arsenic is a poisonous، cumulative substance and inhibitor of SH group enzymes and various studies revealed a significant correlation between high concentrations of arsenic in drinking water and liver cancer، nasal cavity cancer، lungs، skin، bladder and kidney cancer in men and women and prostate and liver in men. The aim of this was survey of arsenic removed from water using dissolved air floatation mechanism. At present study in first step for determination best conditions of arsenic removal by dissolved air floatation method، optimum amount of coagulants determined and then synthetic solution of arsenic (50، 100 and 200 µg/L) prepared using sodium arsenate. In third step arsenic removal efficiency under various variables such as arsenic concentration، flocculation and floatation time and saturation pressure were analyzed. Finally residual arsenic concentration was determined by the silver diethyl dithiocarbamate method. Effect of optimum condition on arsenic removal efficiency at various initial concentration 50، 100 and 200 µg/Lshowed that the best coagulant for removal of arsenic is polyaluminumchloride. Also maximum efficiency (99. 4%) was obtained in initial concentration equal 200 µg/L. It can be concluded that dissolved air floatation method with poly aluminum chloride as coagulant have high efficiency for arsenic removal even at high concentrations and therefore this method can be used for removal of arsenic from water as a suitable and safe option.

Backgrounds and Arsenic is one of the most toxic and dangerous elements in drinking water that with increase in its application in agriculture، development of applications in agriculture، livestock، medicine، industry and other cases its entry to water resources and environment is much easier. Arsenic is a poisonous، cumulative substance and inhibitor of SH group enzymes and various studies revealed a significant correlation between high concentrations of arsenic in drinking water and liver cancer، nasal cavity cancer، lungs، skin، bladder and kidney cancer in men and women and prostate and liver in men. The aim of this was survey of arsenic removed from water using dissolved air floatation mechanism. At present study in first step for determination best conditions of arsenic removal by dissolved air floatation method، optimum amount of coagulants determined and then synthetic solution of arsenic (50، 100 and 200 µg/L) prepared using sodium arsenate. In third step arsenic removal efficiency under various variables such as arsenic concentration، flocculation and floatation time and saturation pressure were analyzed. Finally residual arsenic concentration was determined by the silver diethyl dithiocarbamate method. Effect of optimum condition on arsenic removal efficiency at various initial concentration 50، 100 and 200 µg/Lshowed that the best coagulant for removal of arsenic is polyaluminumchloride. Also maximum efficiency (99. 4%) was obtained in initial concentration equal 200 µg/L. It can be concluded that dissolved air floatation method with poly aluminum chloride as coagulant have high efficiency for arsenic removal even at high concentrations and therefore this method can be used for removal of arsenic from water as a suitable and safe option.

BackgroundsAand Pseudomonas aeruginosa and Staphylococcus aureus are important pathogens that producewidespread infections. Purpose of this studywas to evaluate the antimicrobial effect of ultrasonic irradiation (US) alone and in combination with antibiotic on antibiotic resistance Pseudomonas aeruginosa and Staphylococcus aureus. In this study ultrasonic irradiation (US) in a laboratory-scale batch sonoreactor with low frequency (42 kHz) plate type transducer at 170W of acoustic power was used. The Water samples, were taken from different wards of the 3 teaching hospitals which were affiliated to the Kurdistan University of Medical Sciences to isolate Pseudomonas aeruginosa and Staphylococcus aureus and also to determine their antimicrobial susceptibility pattern.Our results showed that Pseudomonas aeruginosa and Staphylococcus aureus were affected by the ultrasound and the bactericidal effect increased with time. It was found that P. aeruginosa was more susceptible to the ultrasonic treatment than S. aureus. The combination of US with an antibiotic (amoxicillin) enhanced killing of both bacteria over the use of US alone. There were no differences in resistance to ultrasound between isolated strains and standard strains from persian type culture collection.

Backgrounds and Mercury is a heavy metal that is widespread in the environment and has many toxic effects. At present, MeHg exposure on women remain an important issues for researching, especially those of continuous uptake in high-fish consumption.MeHg can be transferred to infant through breast milk. The objective of this study was to characterize the risk of Hg exposure in mothers in south of the Caspian Sea. In this study mercury in hair of 70 breast-feeding women (17-36 years old) and influencing factor on it, were assessed. Mothers lives in nur, nowshahr and chamestan cities and villages of Nur and Nowshahr. In order to researching on influencing factors, mothers fill questionnaires. Hair samples (about 1 gr) were obtained from mothers. The mercury was measured by LECOAMA254AdvancedMercuryAnalyzer (USA) according toASTM, standard NO.D-6722. Total mean mercury concentration in mothers hair obtained 0.19±0.09 (μg gr-1). Tukey test show that the influence of the variables place of live (p=0.02), fish and sea food consumption of mother (P=0.00) were significantly affected on hair mercury concentration of mothers. The other factors (age and number of dental amalgam filling) had no significant effect on mercury levels in hair of mothers. Total mean mercury concentration in mothers hair were lesser than normal dose recommended byWHO (2μg g-1) and EPA reference (5 μg g-1). Analysis of questionnaires showed that three kinds of fish including carp, golden mulle and kutum. Although were often used in this study, mercury concentration in fish was not determined, but in according to significate relation between fish consumption and mercury concentration in mother#s hair, pollution with mercury in the fish can be the main factor of mercury exposure in this study.

Backgrounds and

Total and Fecal coliforms (TC and FC), heterotrophic plate count (HPC), were counted by microbiological method and E.coli O157:H7 were detected through immunological and Real time PCRmethods inwater intake and all of units of Isfahanwater treatment plant (IWTP).

The microbial profile including TC, FC, and HPC, were monitored and turbidity and total organic carbon were analyzed in 8 locations of water intake, and unit operation and processes of IWTP, including, inlet, sedimentation, ozonation, and filtration and finished water. Immunological method through anti-serum kits and molecular method of RT-PCR were used to detect E.coli O157:H7 in the 8 locations and also the sludge of the sedimentation basin and filters backwash water of IWTP.

Survival of E.coli O157:H7 in sludge sample of sedimentation basin was indicated by formation of agglutination particles in immunological method and through indicator probes in the RT-PCR method. However, E.coli O157:H7 was not detected in water samples of other units of IWTP. The removal percent of TC, FC, and HPC were: 59.5, 49, and 54.8 % in sedimentation basin; 66, 45.8, and 57 % in ozonation;: 98.8, 98, and 78.8 in the filtration; and 96, 100, 91% in disinfection, respectively.

This study approved the existence of the pathogenic coliform, E.coli O157:H7 in thesludge of sedimentation basin. Absent of E.coli O157:H7 in the finished water indicates that the existing units of IWTP could eliminate these pathogenic bacteria, before reaching the final units of the plant, including the filters and disinfection.

since large cities of Iran due to specific population, topographic, cultural and economical conditions have a numerous population per surface unit,, results in everincreasing population and it.s accumulation and have prepared favorable conditions for increasing various mice and rats species in these cities. Efforts, designing, construction and evaluation of electronic traps for mouse and rat controlling is one of the controlling methods which may be studied beside the other methods.At first the types and species of mice and rats in Tehran city were studied (including length, weight, behavior characteristics etc.). Next, using a system producing attractive fragrance attracts mouse and rat to the trap. Then, using electronic sensors, mouse presence with commandswhich is sent to electrical bobbins evaluates.Later, themiddle section becomes electrically activated. Contacting the trap, the animal will die within 3 to 5 seconds contacting. Mouse corpse will transfer to the beneath section of trap. This section includes a drawer to be emptied daily or weekly. Preventing electric shocks, the power of all the sections will go with drawing out the drawer. Testing efficiency of the device, it was tried first with lab mice thus in each level of experiences the problems were solved.According to the design, each section of the device including attraction, killing and removing sections were evaluated separately. For instance, in killing section, the amount of voltage and its type also the method of electricity transfer to the animal was evaluated. In addition in attraction section the variety of fragrances were compared and it was found that walnut fragrance gave the best result for all the animal samples attraction. Also, the results showed 300 volts current voltage with 15 Amperes current intensity, has the best killing efficiency in less than a second than other voltages.According to the different evaluations, it was clear there were no good results of killing in 2.5 to 15Amperes direct current intensity. Thus using direct currentmethods in these trap devices were not practical. In addition, using sexual fragrances for attraction males, in several species were tested and results showed that the proteins in these fragrances became decomposed very fast in environmental conditions and the attraction nature of these substances decreased. For this reason it seams according to its easy availability, food fragrances as attraction substances are more practical and useful.