Showing 171 results for Water
Mohaad-Reza Mohebbi, Koshyar Azam Vaghefi, Ahmad Montazeri, Mehrnoosh Abtahi, Sogol Oktahi, Reza Gholamnia, Fatemeh Aliasgari, Reza Saeedi,
Volume 6, Issue 2 (9-2013)
Abstract
Background and objectives: In this research, an innovative drinking water quality index for assessing water resources as “modified drinking water quality index (MDWQI)” was developed and applied for evaluating all of the groundwater resources utilized for community water supply in urban areas of Iran during 2011. Materials and methods: Twenty-three water quality parameters and relevant Iranian standards for drinking water quality were selected as input parameters and benchmarks respectively. The MDWQI is calculated using three factors including the number of parameters that excurse benchmarks, the number of measurements in a dataset that excurse benchmarks and the magnitude of excursions. The MDWQI scores range from 0 to 100 and classify water quality in five categories as excellent (95-100), good (80-94), fair (65-79), marginal (45-64), and poor (0-44). Results: According to the MDWQI value, about 95% of the groundwater resources were in the good condition and the others were in the fair or marginal condition also the best and the worst water quality of water resources were observed in Ardebil Province and Qom Province respectively. The three parameters of fluoride, magnesium, and nitrate recorded the highest rates of violation to be 74, 32, and 13% respectively. Conclusion: The nationwide average score of the MDWQI was 85 (good description). This study indicated that the MDWQI and its sub-indices could describe the overall water quality of water bodies easily, reliably and correctly and have the potential suitability for extensive application all over the world.
Akbar Eslami, Hamzehali Jamali, Shirin Naderi,
Volume 6, Issue 2 (9-2013)
Abstract
Background and Objectives: Water is essential for sustaining life & adequate safe supplies must be accessible to the public. Nowadays, people prefer to purchase bottled water for reasons including taste, convenience, following fashion, and its safety and sanitary conditions. According to the WHO guideline, it is of great importance to control the bottled water because of keeping it for longer period of time and at higher temperature in comparison with the water of distribution networks, reusing containers and bottles without adequate washing and disinfecting, and more growth of microorganisms having less important in the terms of health. The aim of this study was to investigate the microbial and physicochemical quality of bottled water in the stores of Qazvin City and to compare the aforesaid features with national standards and to check the quality with the bottles label.
Materials and Methods: In this cross-sectional study, 51 samples of 11 bottled water brands with different production date were obtained. The features were studied in accordance with Standard Methods. Then, the data were analyzed by T-Test and one way ANOVA analysis using SPSS software. Eventually, the results were compared with the national standards, the WHO guidelines, and the product labels.
Results: Results showed lack of microbial contamination of the samples. Physically and chemically, all the parameters measured were below the national standards level. Study of conformity of the variables to the label indicated that mostly there was a significant difference between the values measured and the values listed on the product labels.
Conclusion: Although the concentration of microbial, physical and chemical features of samples were in the extent of national standards, there was a meaningful difference between labels and measured values so that the average concentration of TDS, TH, SO4-2, Ca2+, Mg2+ and Na+ would be more than the label values and the average of the other parameters was lower than the label values.
Aimohammad Baseri , Rohollah Dehghani , Alireza Soleimani , Omolbanin Hasanbeigi , Mehrangiz Pourgholi, Abdoreza Ahaki , Mohammadbagher Miranzadeh,
Volume 6, Issue 2 (9-2013)
Abstract
Background and Objectives: Kidney patients in each dialysis cycle are exposed to extremely large volume of water, which is in direct contact with the patient’s blood. Hence, the occurrence of any type of contamination in the water used can be very toxic to patients. Thus, quality of water plays an important role in patient well-being. The aim of our study was to investigate the quality of water used for hemodialysis in Kashan Akhavan hospital.
Materials and Methods: This cross-sectional descriptive study was conducted on water quality used for hemodialysis in Kashan Akhavan hospital during Oct.-Nov., 2011. During the study a total of 26 water samples were taken from the raw water and inlet of hemodialysis instrument. Collected water samples were analysed for Heterotrophic plate count, residual chlorine, pH , K+, SO42- , Na+, F- ,Ca2+ , mg2+ ,No3- , Hg+ , Cd2+, Cr6+, Zn2+, Cu2+, Se2+ ,Co2+,Ag +and As2+ according to the standard methods for water and wastewater examination.
Results: Our results showed that the concentration of copper, zinc, cadmium, lead, chromium, and silver were 0.4, 0.6, 0.07, 0.05, 0.08, and 0.04 µgL-1 respectively. In addition, concentration of the chemical elements and heavy metals did not exceed the standard level in any cases. Moreover, no microbial contamination was observed in the samples analyzed.
Conclusion: Based on the results obtained, all water quality parameters in hemodialysis ward of Kashan Akhavan Hospital were compatible with AAMI (Association for the Advancement of Medical Instrumentation) water quality Standards and no health risk threatens the kidney patients.
Mostafa Leili, Gholamreza Moussavi, Kazem Nadafi, Rasoul Khosravi,
Volume 6, Issue 2 (9-2013)
Abstract
Background and Objectives: Furfural with a chemical formula of C5H4O2 is a toxic and hazardous substance for human and environment. Furfural and its derivatives such as furfuryl alcohol, alone or in combination with phenol, acetone or urea are used mainly in the production of resin. The second major application of furfural is in the production of solvents such furan and tetrafuran frequently used as a selective solvent in the production, treatment, and refining lubricants from petroleum products. A few studies have recently been done in terms of removal or recovery of furfural. Due to advantages of biological methods, the uses of theses environmentally friendly methods are being investigated in this study.
Materials and Methods: We used cyclic biological reactor (CBR) and Fusarium culmorum granules to biologically degrade different concentration of furfural and equivalent of COD under different operating conditions. The analysis was based on the measurement of furfural degradation efficiency during operational period using spectrophotometer and measuring influent and effluent COD variations using a closed reflux method.
Results: cyclic biological reactor was operated in various flow rate (Q) of furfural-containing wastewater for a different period. For all of the flow rate used, furfural degradation and COD removal efficiency was over 99 and 90 percent respectively. Fusarium culmorum granules were also exposed to different concentrations of furfural at different incubation temperatures showing high furfural removal capacity. Conclusion: Under different operating conditions of biological systems, high removal efficiency of furfural was observed, but CBR in comparison with Fusarium culmorum granules reached the optimum and desired removal efficiency in shorter time. Therefore, these systems can be developed and replaced with chemical methods to treat furfural containing wastewater.
Amir Hossein Mahvi, Noushin Rastkari, Ramin Nabizadeh Nodehi, Shahrokh Nazmara, Simin Nasseri, Mahboobeh Ghoochani,
Volume 6, Issue 3 (12-2013)
Abstract
Background and Objectives:Chlorination is the most common method of water disinfection. Chlorine reaction with natural organic compounds nor removed completely during treatment process would result in forming disinfection byproducts. Followed by trihalomethanes, Haloaceticacides are the second main byproducts of chlorination in water. The research works conducted in Iran have assessed trihalomethanes. Hence, this is the first time we are reporting haloacetic acids in Iran.
Materials and Methodology: We collected samples from surface water resources and treated water in Tehran for six consecutive months (first half, 2010). We measured temperature, pH, UV adsorption at 254 nm and TOC in each surface water sample and analyzed pH, residual chlorine, and haloacetic acids in the treated water samples.
Results: We found that TOC in surface water resources is 3.6-4.42 and 1.78-2.71 mg/l in spring and summer respectively. Moreover, haloacetic acids concentration was found to be 41.7-55.56 and 34.83-43.73 μg/l in spring and summer respectively.
Conclusion: Our results revealed that concentration of NOM, TOC, and HAAs was more in spring than summer. In addition, concentration of HAAs was depended up on NOM and TOC. Considering maximum permeable concentration of HAAs (60 μg/l) by EPA, it can be claimed that concentration of HAAs was less than the maximum permissible level in all of the samples. However, the immanency of the monitored values to the standard values can be a warning for concerned authorities in water industry.
Afsaneh Alinezhadian, Ahmad Karimi, Jahangard Mohammadi, Farzaneh Nikookhah, Mathias Niuman. Anderson,
Volume 6, Issue 3 (12-2013)
Abstract
Background and Objectives: In arid and semi-arid regions, wastewater reuse has become an important element in agriculture. However, irrigation with this resource can be either beneficial or harmful, depending on the wastewater characteristics. The aim of this research was to investigate the soil bacterial and crops quality irrigated with treated wastewater.
Material and Methods: This research was conducted on a maize field near the wastewater treatment plant in Shahr-e-kord in summer,2011. Plots were arranged in a randomized complete block design in 3 replications and 2 treatments, well water (W1) with fertilizer and effluent (W2).
Results: At the end of growth season, soil samples were collected from depth of 0-5 and 5-15 cm and plant samples consisting of old and new leaves and seeds were collected for bacteriological analysis. According to bacteriological analysis, total number of positive lactose bacteria, total and fecal coliforms in depth of 0-5 cm was 42% more than depth of 5-15 cm. In the case of old leaves, total number of coliform and fecal coliform was 88 and 40 MPN/100 mL respectively. Moreover, for new leaves, it was 38 and 2 MPN/100 ml respectively.
Conclusion: According the results, number of indicator bacteria in soil is decreased (about 35%) by passing time.
Mohammad Taghi Ghaneian, Mohsen Amrollahi, Mohammad Hassan Ehrampoush, Mahboobeh Dehvari,
Volume 6, Issue 3 (12-2013)
Abstract
Background and Objectives: Water complexes including Jacuzzi are among the most popular water recreation centers that noncompliance with health standards can lead to increased microbial growth in water and thus the risk of infection. This study aimed at comprehensive study of jacuzzis water in Yazd city and comparing the results with national and international standards. Materials and Methods: This was a descriptive - analytical study that statistical society included all Jacuzzis of Yazd city. Sampling of jacuzzis was performed every two weakes for 3 months (Summer 2011). We tested the water samples for parameters such as temperature, pH, amount of residual chlorine, turbidity, alkalinity, hardness, the population of heterotrophic bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, fecal streptococci, and fecal coliforms accordance with standard methods. The SPSS software and ANOVA, T-test statistical tests, and/or Kruskal-Wallis, and Mann-Whitney were used for description of data and the obtained results were analyzed by comparing with standards. Results: we found that the mean of residual free and combined chlorine was equal to 0.628 and 0.337 mg/l respectively. The alkalinityand hardness were 141.928 and 275 mg/lCaCo3 respectively. Mean of pH, turbidity and temperature were equal to 7.88, 0.457 NTU and 38.121˙C respectively.Moreover, the mean population of fecal streptococci bacteria, heterotrophic bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, and fecal coliforms were 20465.7, 120.77, 209.91 and 7131.4 in 100 ml respectively. Statistical analysis of data showed that there is a direct relationship between water turbidity and pH (Pvalue=0.018) however, population of heterotraphic bacteria and residual free chlorine had indirectl relationship (Pvalue= 0.026). Conclusion: According to the results achieved, the parameters of heterotrophic bacteria population and alkalinity had the least compliance with the standard indicating the need for continuous monitoring of physical, chemical, and microbial parameters of Jacuzzi water and control of the number and density of people using Jacuzzi and continuous monitoring of Jacuzzi water filtration and chlorination process performance.
Gh Asgari, A. R. Rahmani, A. R. Dehghanian, A. R. Soltanian,
Volume 7, Issue 1 (7-2014)
Abstract
Background and Objectives: In this experimental study, we used Analytical Hierarchy Process method to determine the best wastewater treatment process for dairy products factories. That is a multi-criteria decision making techniques and is based on expert knowledge. Materials and Methods: First, we formed the hierarchical structure and defined the main criteria and indicators. Then, we investigated the current situation of the treatment process through field observations and conducting influent-effluent analysis. Later, we converted the results obtained into quantitative indices. Then we weighted the main criteria, and their related sub criteria, depending on existing conditions we performed the experiments required and considered the experts ideas. Finally, Evaluation and prioritization of the options was conducted using Expert choice software. Then the sensitivity analysis was performed for main criteria and we evaluated the influence of the parameters weight change on the options. Results: In comparison with the main criteria, environmental criteria were more important followed by engineering criteria, economic and management criteria. Conclusions: Due to the influence of various parameters in choosing optimal wastewater treatment, Multi-criteria decision-making methods are necessary. Finally, “UASB + Aeration” was found to be the first priority followed by “Anaerobic filter + Aeration”, “Anaerobic lagoon + Aeration (2) + Sedimentation (2)”,” Anaerobic filter + Aeration (2) + Sedimentation (2)”. “Septic tank + Trickling filter + Aeration” system was found to be less preferable than other options.
N Navidjouy, M Jalali, H Khorsandi, Hossein Movahedian,
Volume 7, Issue 1 (7-2014)
Abstract
Background & Objectives: Listeria bacterium resists to the sludge digestion conditions and Listeria monocytogenes is the most important of them. Sludge produced in the north Isfahan wastewater treatment plant is stabilized by anaerobic digesters and is used for fertilizing agricultural lands after drying in the sludge drying beds. Based on the importance of the subject, the objective of this study was evaluation of sludge processing units efficiency, particularly anaerobic sludge digestion for reduction or removal of Listeria. Materials and Methods: In this descriptive study, samples were collected weekly from sludge processing units 13 times in north Isfahan wastewater treatment plant according to standard methods over three months. Listeria bacteria were enumerated and isolated by triple-tube fermentation method and U.S Department of Agriculture method respectively. Isolated Listeria were confirmed by phenotypic method and then bacterial species were diagnosed differentially by biochemical carbohydrate fermentation and CAMP test. Results: Contamination of raw, stabilized and dried sludge at least to one of L. Monocytogenes, L. Innocua and L. Seeligeri species was 100, 92.3 and 53.8 percent respectively. Anaerobic sludge digesters efficiency to remove L. Monocytogenes, L. Innocua and L. Seeligeri species was determined 64.7, 39.72, and 100 percent while the efficiency of drying sludge beds for L. monocytogenes and L.innocua species removal was 73.4 and 96.68 percent respectively. Conclusion: Listeria monocytogenes is more resistant than other identified species against the sludge processing conditions. Thus, the use of sludge as fertilizer can cause the spread of this bacterium in the environment and agricultural products pollution.
Samaneh Ghodrati, Gholamreza Moussavi,
Volume 7, Issue 2 (10-2014)
Abstract
Background and objectives: Electrocoagulation (EC) as an electrochemical method was developed to overcome the drawbacks of conventional decolorization technologies and is an attractive alternative for the treatment of textile dyes. This study was aimed at the optimization of the EC process for decolorization and COD removal of a real textile wastewater using response surface methodology (RSM). RSM is an important branch of experimental design and a critical technology in developing new processes, optimizing their performance, and improving design and formulation of a new products. Materials and Methods: In this study, a bench scale EC reactor was designed, constructed, and studied for treatment of a textile wastewater. The main operational variables were current intensity, residence time, initial pH, and electrode materials as independent variables color and COD removal were considered as dependent variables. The experimental runs were designed using selected variables using Design Expert 7.0 software and the process was optimized for decolorization and COD removal using the response surface method. Results: The optimal operational conditions in the EC process for attaining the maximum decolorization and COD removal were current density of 0.97 A, initial pH of 4.04, residence time of 48 min, and Fe electrode. The desirability factor for Fe electrode was 1, while decolorization and COD removal were predicted 76.3 and 75.6% respectively, which was confirmed by the experimental results. Conclusion: The experimental results indicated that the EC process is an efficient and promising process for the decolorization and COD removal of textile effluents. Under the optimized conditions, the experimental values had a good correlation with the predicted ones, indicating suitability of the model and the success of the RSM in optimizing the conditions of EC process in treating the textile wastewater with maximum removals of color and COD under selected conditions of independent variables.
Amir Hossein Javid, Seyed Ahmad Mirbagheri, Arezoo Karimian,
Volume 7, Issue 2 (10-2014)
Abstract
Background and Objectives: Dez dam located on Karun River is one of the largest Iranian dams. In a field study, EC, NO3, NH4, PO4, turbidity, TS, alkalinity, coli, temperature, chlorophyll a, DO, BOD5, and Secchi disk (at depths of 0, 2.5, 5, 10, 25, and 50 m)were measured at five sampling points during 2011-2012 water year. Materials and Methods: Water Quality Index and TSI were calculated for all sampling points and quality zonation was conducted in GIS. Results: It was found that the best water quality index for reservoir water is at second sampling point with amount of 61 situated at the center of reservoir, and the worst index is at entering point to the reservoir with amount of 46 in April. The main reason of changes was turnover of thermal stratification. Conclusion: The laboratory analysis and assessing the quality indices revealed that the Dez reservoir water is suitable for variety of public uses, however, it needs advanced treatment for drinking purpose. Moreover, in the case of continuity of pollutant entrance into the reservoir, the eutrophication risk would threaten the reservoir water quality. Eutrophication occurrence will cause serious limitations in water use applicability, increase turbidity, produce toxic materials, and increase sedimentation regime.
Samira Akhavan, Hamid Zare Abyaneh, Maryam Bayat Varkeshi,
Volume 7, Issue 2 (10-2014)
Abstract
The objective of this study was to collect all the conducted studies on nitrate concentration in water resources of Iran. To achieve this purpose, the published papers in ISC and ISI journals as well as conferences and seminars were evaluated. The results of this survey showed that 116 studies have been carried out in 26 provinces of Iran. But,there was no published paper in Ilam, Alborz, South Khorasan, Kohgiluyeh and Boyer-Ahmad, and Lorestan provinces. According to these studies, the largest number of studies was performed in Hamadan province (14 cases), Khuzestan, and Mazandaran provinces (10 cases) and the least number of studies was conducted in Ardabil, Bushehr, Qazvin, Qom, and Kermanshah provinces. In Hamadan province, more than 1435 water samples were collected from water resources of this province, which is representative of large number of studies in this region. Maximum nitrate concentration (318 mg/L) was reported in Isfahan province and then in Zahedan city (295 mg/L), Sistan and Baluchestan Province. Based on the reported results in these studies, the nitrate pollution in water resources of Iran is at medium level. In most of the studies, high nitrate concentrations are due to lack of sewage collection network, discharge of urban and industrial sewage to water resources, and agricultural activities, which use high amounts of manure and fertilizer.
Hossein Banejad, Atieh Zarei, Ali Akbar Safari Sinegani, Farshad Dashti,
Volume 7, Issue 2 (10-2014)
Abstract
Background and Objectives: Reuse of treated wastewater in agriculture is becoming more attractive due to the growing demand for water, particularly in arid and semi-arid regions like Iran.In some areas, industrial wastewaters distribute arsenic in the water and vegetables, among the other plants, are mainly irrigated by municipal and industrial wastewater. This study aimed to evaluate the outcome of radish irrigation using water contaminated with arsenic and zinc and to measure the zinc concentration in the edible parts of radish plant. Materials and Methods: The experiments were designed in the form of a factorial completely randomized design with three replications in which radishes were planted in pots about five kilograms. Arsenic concentration at four levels (0, 100,300 and 600 µg/l) and zinc concentration at three levels (0, 10, and 50 mg/l) were added to the irrigation water. The pots were equally irrigated once every 3 to 4 days. After harvesting and laboratory operations, zinc concentration was measured using atomic absorption spectroscopy. Results: The study indicated that zinc concentration in radish tubers is correlated with the concentration of zinc in water. The results of the analysis of variance table for the effect of zinc and arsenic-contaminated irrigation water on zinc concentration in radish roots, tubers and leafs show only one treatment (zinc concentration in water) on the property is significant at 5 and 1%. The results of the comparison table revealed that Zn uptake was decreased with increasing arsenic up to 300 µg/l. Conclusion: It was found that zinc concentration in radish roots, tubers, and leafs is correlated with the concentration of zinc in water. Moreover, there was a competition between the absorption of zinc and arsenic in plants. With increasing arsenic in irrigation water, transition of Zn was reduced to aerial part.
M. Arbabi, M.a. Ahmadi, M. Sedehi,
Volume 7, Issue 3 (5-2014)
Abstract
Background and Objectives: Bakery’s yeast industry wastewater contains various pollutants and is generally characterized with high chemical oxygen demand (COD), dark color, high-nitrogen and sulfate and non-biodegradable organic pollutants. Having persistent soluble colored compounds (called melanoidins), effluent from yeast industry is a major source of water and soil pollution. The aim of this study was to evaluate advanced oxidation efficiency using Fenton process for COD and color removal from bakery’s yeast wastewater. Materials and Methods: This was an experimental- laboratory scale study. In this study, the effect of time and Fenton concentrations were tested for COD and color removal from bakery’s yeast wastewater. The sample used for this study was yeast effluent from Separator 2 with initial concentrations of COD and color of 5300 mg/L and 6950 pt-co respectively. In order to obtain the optimum operating conditions of the process, Taguchi analysis method was used. Experiments were carried out in five stages of the time in the range of 15, 30, 45, 60 and 75 min with various concentrations of hydrogen peroxide (e.g., 0.02, 0.04, 0.06, 0.08, and 0.1 molar) and concentrations of Fe2+ (e.g., 0.01, 0.02, 0.03, 0.04, and 0.05 molar) at pH = 3. Jar test method was used to determine the best operating conditions including: reaction time, dosages of hydrogen peroxide and Fe2+. Results: According to Taguchi method and SN-ratio analysis, the best H2O2/Fe2+ dosages were 0.08/0.04 molar at pH 3 and in reaction time of 30 min for removal of COD and color. For these conditions, the maximum COD and color removal efficiencies were 63 and 69 percent respectively. Based on the results, with increasing reaction time, there was no perceptible change in the removal efficiency. Conclusion: It can be concluded that Fenton’s oxidation method can be used successfully, as an alternative option to the design and choice of color and COD removal from strength industrial wastewaters e.g., bakery’s yeast industry.
A Azhdarpoor Esfanabadi, P Mohammadi, M Dehghani,
Volume 7, Issue 4 (1-2015)
Abstract
Background & Objectives: Excessive discharge of hazardous materials such as nitrogenous and organic compounds into the environment has negative impacts on the health of the aquatic environment. The main objective of this research was focused on evaluating the feasibility of using modified SBR reactor for the removal of nitrogenous compounds and chemical oxygen demand (COD). Materials & Methods: The experiments were performed using an up-flow continuous reactor with intermittent effluent. At first, four different cycles including aeration, settling, and decant (3, 4, 6, and 8 h) were designed for the performance of the reactor. Then, the efficiency of each cycle was determined for different concentrations of COD (250-1500 mg/L) and ammonia (40-100 mg/L). Results: Data demonstrated that all cycles had very good performances for the removal of COD. The average COD removal efficiencies of phases 1 through 4 were 91.7, 91.5, 92, and 92.7% respectively. The average NH4+ removal efficiencies of phase 3 and 4 were 92.7 and 95.8% respectively. Conclusion: The performance of phase 4 (with the cycle of 8 h) for the removal of nitrogen compound and COD was particularly high. The combination of anoxic and aerobic cycles in the reactor and providing nitrate as an electron receptor had the best performance for the removal of nitrogen from wastewater. Therefore, the continuous up-flow reactor was a good alternative to batch reactor in removing nitrogen compound and COD simultaneously.
H Khorsandi, A Mohammadi, F Kariminejad, M Haghighi, R Alizadeh,
Volume 7, Issue 4 (1-2015)
Abstract
Background & Objectives: Entering LAS through the wastewater plant’s effluent to water resources causes taste and odor changes, aquatics death, oxygen transfer limitation, and disorders in water treatment processes. Therefore, the study objective was to determine optimum conditions for fenton oxidation process to remove linear alkyl benzene sulfonate from aqueous environments using taguchi method and its requirement evaluation for additional treatment of Biolac effluent. Materials &Methods: LAS removal using Fenton oxidation was evaluated in a 500 mL laboratory-scale batch reactor. In order to save the costs, to determine the optimum conditions of the Fenton oxidation, 25 runs were computed using Taghuchi method by Minitab 16 software. Sampling and required tests were performed based on standard methods examination for water and wastewater. For evaluation of Biolac process sufficiency in LAS removal, biolac efficiency in Urmia Wastewater Treatment Plant was studied in 2012. Results: Based on the LAS removal and chemicals required, Minitab software (Ver. 16) recommended the optimum conditions of Fenton oxidation at 900 mg/L H2O2, 170 mg/L Ferrous ion, pH of 4, and reaction time of 20 minutes. It was found that the Fenton oxidation for LAS removal had 86.5% efficiency under optimum condithions and it was second order reaction with the rate coefficient of 0.0152 L/mg.min. Biolac process does not need any additional treatment due to meeting LAS standard in municipal wastewater treatment. Thus, this process decreased annually mean LAS from 5.28 mg/L to 0.734 mg/L in municipal wastewater. Conclusion: Although the Fenton oxidation appears as a chemical process with high efficiency in the removal of LAS, the low efficiency of COD corresponding to the LAS indicated partial decomposition of linear alkyl benzene sulfonate by Fenton oxidation.
A Bazzi,
Volume 8, Issue 1 (8-2015)
Abstract
Background & Objectives: This paper, discussed the concentrations of heavy metals such as cadmium, copper, lead, zinc, nickel, chromium, iron, and magnesium in surface sediments of the Gulf of Chabahar. Materials & Methods: Samples of coastal sediment and shallow waters were collected from five different stations in summer and winter, 2013. Results: The research found that the concentrations of heavy metals in sediments is more than water, although the concentrations of metals in sediment and water from different stations followed a general trend. Seasonal variation had effect on the concentration of metals, so that in winter, the concentration of heavy metals such as copper, lead, zinc, cadmium, and nickel was more than of the summer season. Conclusion: Generally, concentration of heavy metals in the study area was less than the quality guidelines for sediments and water. However, between different stations, higher concentrations of heavy metals were found in stations nearby the fishing ports. The results show that increase in the concentrations of heavy metals can contribute considerable impacts on the pollution level due to fishing boats in the study area although some metals are also of natural origin.
A Mogadam Arjmand, M Rezaee, S Naseri, S Eshraghi,
Volume 8, Issue 1 (8-2015)
Abstract
Background & Objectives: Cryptosporidium parvum is considered as one of the pathogenic agents transmitted by water, high resistance to conventional disinfection methods, and potency of creating various problems in water resource. Because of various problems in Cryptosporidium parvum studies, Bacillus subtilis spore is recommended as a surrogate organism for studying protozoa inactivation and evaluation of water quality. On the other hand, electrochemical process is presented as an environmental friendly and high efficient method in disinfection in recent years. The aim of this study was to propose a method for promotion of the water quality. Materials & Methods: In this study, the electrochemical system used was consisted of steel electrodes (4×8 cm), 200 mL volume, and 1-4 mg/L sodium chloride. The bacterial suspensions of Bacillus subtilis (ATCC 6633) was prepared according to the McFarland method with 103 to 106 spores/mL concentration. The microbial agent removal was evaluated by sampling and transferring water to the tripticase soy agar medium every 15 min for 60 min. The number of bacteria spores, supporting electrolyte, induced current, and reaction time were evaluated. Results: The proposed electrolysis process could not eliminate Bacillus subtilis spores at 104 to 106 spores mL-1 rate at lower than 100 mA current for 60 min. Adding sodium chloride supporting electrolyte up to 4 mg/L concentration completely eliminated Bacillus subtilis spores after 60 min. Conclusion: Adding sodium chloride as a supporting electrolyte can increase the spore removal because of increasing direct and indirect oxidation in electrolysis process. Improving water disinfection and spore removal after 60 min could be described by higher oxidant agents in anode electrode.
M Malakootian, A. H Mahvi, H Jafari Mansoorian, M Alizadeh, A.r Hosseini,
Volume 8, Issue 2 (8-2015)
Abstract
Background and Objective: Phenol and phenol derivatives in industrial wastewater are among the pollutants with priorities. The high cost and low efficiency of some routine treatment processes of industrial wastewater has limited their use. One of the new methods under consideration is, nowadays, adsorption using carbon nanotubes. This study was conducted in order to evaluate the application of alumina-coated multiwall carbon nanotubes in eliminating phenol from synthetic wastewater. Materials and Methods: This study was performed in laboratory at batch scale. Multi-wall carbon nanotubes were coated with Alumina. The concentration of phenol was determined by spectrophotometer through photometry. The effect of pH changes, dosage of adsorbent, contact time, the initial concentration of phenol, temperature, and the concentrations of different salts on the efficiency of absorption was evaluated. Then, the absorption results were described using the Langmuir and Freundlich isotherms and the synthetics of absorption. Results: It was found that absorption efficiency increased significantly by decreasing the initial concentration of phenol and pH and by increasing the carbon nanotube dosage, temperature, and contact time. On the other hand, the maximum elimination of phenol from the solution (98.86%) occurred at 4 mg/l phenol concentration, under acidic conditions (pH=3), at adsorbent dosage of 0.05 g/l, at temperature of 45°C, and contact time of 10 min. Evaluation of the regressions isotherms showed that the process follows the Langmuir model and second-degree synthetic absorption. Conclusion: The high efficacy (98%) of the adsorption process in this study showed that alumina-coated multiwall carbon nanotubes have a good capability in eliminating phenol and can be used as an appropriate and new method for eliminating phenol and its derivatives from wastewater.
K Naddafi, A Beiki , R Saeedi, G Ghanbari, A Niati, L Sori,
Volume 8, Issue 3 (12-2015)
Abstract
Background and objectives: In the outbreak of infectious diseases, the on time epidemiological, environmental, and laboratorial investigations result in rapid diagnosis of cause and source of the outbreaks and decrease the diseases spread and public health loss. Following the outbreak of gastroenteritis in Pardis Town in January 2014, this research was conducted to identify the cause, source, and route of transmission of the outbreak.
Materials and methods: First, the descriptive epidemiological study was conducted using checklist and the stool samples were prepared and analyzed. The drinking water quality in Pardis during and before the outbreak was obtained from National Environmental Health Network. The community water supply system consisting of watershed, water resources, pipelines, storage reservoirs, disinfection systems, and distribution network were inspected and sampling and detection of thermotolerant coliforms and norovirus in water samples were performed according to the Standard Methods.
Results: There were 6,027 patients with symptoms of nausea, vomiting, cramps, mild diarrhea, and mild fever. The distribution of the disease in all age groups, gender, ethnicity, and location was uniform. Out of nine stool specimens, molecular testing of norovirus in six samples was positive. Hazards identified in the water supply system consisted of a water pipe fracture occurred two days before the outbreak, illegal connection of landscape irrigation system to the drinking water supply network, the use of unprotected Fellman wells as the resource of water supply, and discharge of domestic wastewater into the water resource upstream of the Fellman wells. The water samples taken from the Fellman wells had fecal contamination (11 out of 12 samples), but because of weakness and limited experience in identifying norovirus in water samples, norovirus was not detected in the raw water samples.
Conclusion: This study showed that the pathogen came from a single source. Clinical symptoms, epidemiological evidence, the results of analysis of human stool samples, fecal contamination of raw water samples and norovirus resistance to the standard amounts of free residual chlorine in water indicated that the outbreak caused by consumption of contaminated drinking water (discharge of domestic wastewater to water supply system). In order to prevent similar outbreak, resolving the observed bugs in the water supply system and implementation of water safety plan is recommended.