Journal of Environmental Health Science & Engineering73CHROMIUM REMOVAL USING VARIOUS BIOSORBENTS182190M.SenM.Ghosh Dastidar20151209Pollution of water due to presence of certain heavy metal ions is a severe socio-environmental problem caused by the discharge of industrial wastewater. In view of their toxicity, non-biodegradebility and persistent nature, their removal becomes an absolute necessary. Chromium is one of the major pollutants in the environment and is frequently present in wastewaters from various industrial units. Several conventional physical and chemical treatment techniques may be used for the removal of chromium. However, such processes are not only expensive and highly energy intensive, but also lead to production of harmful by-products and end-products, the ultimate disposal of which again causes secondary pollution. Hence, the potential application of microorganisms as biosorbent for the removal of chromium has been recognized as an alternative to the existing conventional physico-chemical methods. The aim of the present study is to review the removal of chromium from aqueous solution using various materials of agricultural and biological origin , which have been studied as potential chromium biosorbent (plant leaves, saw dust, sugar cane bagassa, sugar beet pulp, maize cob and rice hulls). Also reported cases on chromium removal from aqueous solution by using fungal, algal and bacterial biomass under the growing, resting and dead conditions in batch as well as in continuous bioreactors are reviewed.https://ijehse.tums.ac.ir/index.php/jehse/article/view/247https://ijehse.tums.ac.ir/index.php/jehse/article/download/247/246Journal of Environmental Health Science & Engineering73INFLUENCE OF BIOAUGMENTATION IN BIODEGRADATION OF PAHs-CONTAMINATED SOIL IN BIO-SLURRY PHASE REACTOR199208S.NasseriR.KalantaryN.NouriehK.NaddafiA.MahviN.Baradaran20151209Polycyclic Aromatic Hydrocarbons (PAHS) are important pollutants which have toxic, carcinogenic and mutagenic properties and are considered as a serious hazard to human health and environment. Bioremediation of PAHs contaminated soil was studied in the soil slurry phase bioreactor. For enhancement of biodegradation, bioaugmentation (which is the process of adding microorganisms with the potential of pollution biodegradation to the bio-slurry reactor) was applied. Phenanthrene (C14H10), a three-benzene ring PAHs, was added in concentration of 100mg/kg soil. Two isolated species and consortium of bacteria were inoculated to the medium in density of 7×107 CFU/mL. The analysis of variance (ANOVA) was used for finding of optimum levels of type of bacterial culture and presence effect of endogenous factors. The base of the bacteria was petroleum-contaminated soil from around Tehran petroleum Refinery. Control reactor (killed bacteria) showed 5% loss of phenanthrene and biodegradation in the non-augmented reactor (endogenous microorganisms) in a slurry bioreactor was about 17%. In the case of bioaugmentation with Pseudomonas.spp, Pseudomonas aeruginosa and consortium, phenanthrene degradation efficiency were 87.8%, 85.5% and 92.8% ,respectively, presenting the positive effect of biodegradation in consortium augmented compared to the isolated one. Colony forming units (CFUs) variation showed good conformity and agreement with the performance of the reactors with respect to phenanthrene degradation. Hence, the results of this experiment show that bioaugmentation may be considered as an effective method to enhance the bioremediation in removal of PAHs from contaminated soils.https://ijehse.tums.ac.ir/index.php/jehse/article/view/248https://ijehse.tums.ac.ir/index.php/jehse/article/download/248/247Journal of Environmental Health Science & Engineering73CLEANING OIL-CONTAMINATED VESSEL BY EMULSAN PRODUCERS (AUTOCHTHONOUS BACTERIA)209222P.ChamanrokhM.Mazaheri AssadiGh.AmoabedinyH.Rashedi20151209In a process for cleaning hydrocarbonaceous residues, including residual petroleum from laboratory made oil-contaminated vessels, several previously isolated bacteria from Ilam and Paydar oil reservoirs, were used. The isolated strains were compared with the standard sample of Acinetobacter calcoaceticus PTCC 1318 from Persian Type Culture Collection (PTCC). This gram-negative bacterium grows on a variety of different substrates as sole carbon and energy sources, including crude oil, soy oil and ethanol. It is oxidase-negative, non-motile and strictly aerobic. Among the isolated strains, two autochthonous strains were found to produce an extracellular emulsifying agent when grown in Mineral Salt Medium containing soy oil, ethanol or local crude oil. The crude emulsifier of PTCC1318, Paydar-4 and Ilam-1 were concentrated from the cell-free culture fluid by ammonium sulfate precipitation to yield 1.89 g, 1.78 g and 1.69 g of bioemulsan, respectively. Although measuring the surface tension (ST) is not very applicable procedure in case of bioemulsan, but in order to prove this theory, ST was conducted.Further analysis of purified emulsion was performed to prove the molecular structure by Carbon13 Nuclear Magnetic Resonance, Proton1Nuclear Magnetic Resonance and Fourier Transform Infrared Radiation methods. These investigations showed that the molecular weight of emulsion produced by species isolated from Ilam and Paydar crude oil reservoirs are comparable with Acinetobacter calcoaceticus PTCC 1318.https://ijehse.tums.ac.ir/index.php/jehse/article/view/249https://ijehse.tums.ac.ir/index.php/jehse/article/download/249/248Journal of Environmental Health Science & Engineering73EFFECT OF NANOSILVER PAINTING ON CONTROL OF HOSPITAL AIR-TRANSMITTED MICROORGANISMS223228K.NaddafiH.JabbariM.Chehrehei20151209Microorganisms, including bacteria and fungi, are among air-transmitted infectious agents at hospitals, which in addition to patients, can afflict hospital employees and visitors, and may result in economic burden and impact on human health. Although application of physical and chemical methods for control of microbial growth is not a new subject, but the use of nanotechnology and especially nanosilver painting is a new method applied in this area. This study was aimed to assess antibacterial and antifungal effects of nano-silver painting. Three rooms were selected in an infectious diseases unit of a university-based tertiary referral hospital affiliated to Tehran University of Medical Sciences. One of the rooms was painted with ordinary paint having no nano-particle (as control room) and the other two rooms were painted with two different 2% nanosilver paints ( one locally produced and other provided from abroad) provided from two different companies (as case rooms). Air sampling was carried out using a portable air pump (Quick Take 30 with constant rate between 10 and 30 L/min from 1 to 999 minutes) at pre-planned schedule. Each sampling was done in two minutes with the rate of 28.3 L/min. Samples were transferred on Blood agar (for total bacterial growth), EMB agar (for Gram negative bacterial growth) and Sabouraud>s Dextrose agar (for fungi detection) medias to study the culture results and Colony Forming Unit (CFU) count. Results, tested by ANOVAs and Kruskal-Wallis methods, indicated that there was no statistically significant reduction in the bacterial and fungal bio- burden between the control and case rooms and also between two types of paints by active sampling method. Moreover, there was no selective statistically significant change in bacterial and fungal species CFUs collected from the painted rooms by the above mentioned method. Study also revealed that there is no time trend change in bacterial bio- burden of the under study case and control rooms except for the first time zone (one month) of study duration.https://ijehse.tums.ac.ir/index.php/jehse/article/view/250https://ijehse.tums.ac.ir/index.php/jehse/article/download/250/249Journal of Environmental Health Science & Engineering73TREATMENT OF LOW-STRENGTH INDUSTRIAL WASTEWATER USING ANAEROBIC BAFFLED REACTOR229240A.TorabianS.AbtahiM.AminS.Momeni20151209The performance of an anaerobic baffled reactor at the pilot scale, with a 100-L volume and six compartments, that is used to treat low-strength industrial wastewater (671.5±49.9 mg COD/L, 350.1±36.8 mg BOD5/L and 443.8±60.7 mg SO4-2/L) was studied. The reactor was started with a hydraulic retention time (HRT) of 25 h at 35 ºC, which was gradually reduced to 3.33 h. The best reactor performance was observed with an organic loading rate (OLR) and a sulfate loading rate (SLR) of 4.45 g COD/L.d and 3.32 g SO4-2/L.d, which was obtained at a HRT of 4 h. The COD and SO4-2 removal efficiencies were 78.6% and 89.2%, respectively. Additionally, the majority of the COD and SO4-2 removal occurred in the first compartment, up to 51.2% and 69.1%, respectively. Moreover, the pH in the first compartment was also the lowest. Subsequently, when the temperature was reduced to 20 ºC at a HRT of 4 h, the maximum removal efficiencies for COD and SO4-2 decreased to 59.4% and 66.1%, respectively. In this case, the highest COD and SO4-2 removal efficiencies were observed in the third and fourth compartments, respectively, and these compartments had lower pH values. This phenomenon indicates that decrease in temperature causes transference of the acidogenic phase toward subsequent reactor compartments. In addition, these findings further show the potential for sulfate removal of the acidogenic phase.https://ijehse.tums.ac.ir/index.php/jehse/article/view/251https://ijehse.tums.ac.ir/index.php/jehse/article/download/251/250Journal of Environmental Health Science & Engineering73METHYL TERT-BUTYL ETHER ADSORPTION ON SURFACTANT MODIFIED NATURAL ZEOLITES241252S.GhadiriR.NabizadehA.MahviS.NasseriH.KazemianA.MesdaghiniaSh.Nazmara20151209Surfactant-modified clinoptilolite-rich tuff was used for the removal of methyl tert-butyl ether (MTBE) from aqueous solutions. Clinoptilolite zeolite from Miyaneh region of Iran was treated with sodium chloride and then modified with hexadecyltrimethylammonium chloride (HDTMA-Cl) and n-Cetylpyridinium bromide (CPB) to be used in different experimental conditions. The ability of raw or Non-Modified Zeolite (NMZ) and Surfactant-Modified Zeolites (SMZ) to remove MTBE from aqueous solutions was investigated as a function of contact time, pH and concentrations of adsorbent and adsorbate, by using a batch technique in aqueous system. The removal of MTBE from aqueous solutions by modified zeolites seemed to be more effective than non-modified samples. Also, HDTMA-modified zeolite had more effective performance than CPB-modified zeolite. The adsorption efficiency of MTBE onto SMZS was found to increase by contact time and adsorbent concentrations, and by decreasing of pH and adsorbate concentrations. Empirical adsorption models of Langmuir and Freundlich were applied for the experimental data. Results showed that Langmuir isotherm was more suitable for this process. The experimental data fitted very well with the pseudo-second-order kinetic model. It was overally found that Surfactant-Modified Zeolites is an effective adsorbent for removal of methyl tert-butyl ether from contaminated solutions.https://ijehse.tums.ac.ir/index.php/jehse/article/view/252https://ijehse.tums.ac.ir/index.php/jehse/article/download/252/251Journal of Environmental Health Science & Engineering73HAMADAN LANDFILL LEACHATE TREATMENT BY COAGULATION-FLOCCULATION PROCESS253258M.SamadiM.SaghiA.RahmaniJ.HasanvandS.RahimiM.Shirzad Syboney20151209In most countries, sanitary landfilling is the common way to dispose municipal solid wastes. In the operations, leachate treatment is a difficult and expensive process. Although, leachate can be treated by biological processes, COD removal efficiency is usually low due to high ammonium ion content and the presence of toxic compounds such as metal ions. This experimental study was conducted to investigate the effect of coagulation-flocculation process on the Hamadan landfill leachate treatment in the city of Hamedan. Also the effects of different coagulants with various dosages and pH values in the removal of chemical oxygen demand (COD) and total suspended solids were studied. Results showed that the efficiency for COD removal by Poly Aluminum Chloride at pH=12 and 2500 mg/L of coagulant, by alum at pH=12 and 1000 mg/L of coagulant dose and by ferrous sulfate at pH=12 and 1500 mg/L of ferrous sulfate dose were 60%, 62.33% and 70.66%, respectively. Also results showed that, the efficiency for Total Suspended Solids removal by Poly Aluminum Chloride that was obtained at pH=12 and 2500mg/L concentration of Poly Aluminum Chloride, by alum at pH=2 and 1500 mg/L concentration of alum and by ferrous sulfate at pH=7 and 2500mg/L of ferrous sulfate, were 39.14% , 58.37% and 35.58%, respectively. Based on results of this study, the best coagulant for COD removal was ferrous sulfate and the physico-chemical process may be used as an effective pretreatment process, especially for young leachate, prior to post-treatment (polishing) for partially stabilized leachate.https://ijehse.tums.ac.ir/index.php/jehse/article/view/253https://ijehse.tums.ac.ir/index.php/jehse/article/download/253/252Journal of Environmental Health Science & Engineering73MODELLING ENERGY CONTENT OF MUNICIPAL SOLID WASTE USING ARTIFICIAL NEURAL NETWORK259266T.OgwuelekaF.Ogwueleka20151209The application of artificial neural network on energy modeling needs to be researched more extensively in order to appreciate and fulfill the potential of this modeling approach. The estimation of lower heating value is required to know the actual available energy to be converted to heat or electricity. In this study, a feed forward artificial neural network, trained by error back propagation algorithm was used to predict the lower heating value of municipal solid waste. Plastic, paper, glass, textile and food were found to be essential for prediction of lower heating value of municipal solid waste. The lower heating value has strong relationship with plastic, paper, glass, textile and food. Using 60 dataset divided into 37 training dataset and 23 validating dataset, gathered from Abuja waste stream, artificial neural network was trained and validated. The efficiency and accuracy of the artificial neural network was measured based on absolute average error and determination coefficient. The artificial neural network produced results with an absolute average percentage error less than 9.13% and 9.4% for training and validating dataset, respectively, when compared to measured data. The model provided the best fit and the predicted trend followed the observed data closely; the determination coefficient for training and validating dataset were 0.992 and 0.981, respectively. These results show that artificial neural network is an effective tool in forecasting energy content.https://ijehse.tums.ac.ir/index.php/jehse/article/view/254https://ijehse.tums.ac.ir/index.php/jehse/article/download/254/253Journal of Environmental Health Science & Engineering73COLOR REMOVAL FROM WATER BY COAGULATION/CAUSTIC SODA AND LIME267272M.MalakootianA.Fatehizadeh20151209Due to aesthetic aspects, use of colored water even approved hygienically, is not acceptable worldwide. Consumers prefer to use colorless water. Color in water is usually associated with aromatic compounds produced from decay of natural herbal substances. Undesirable taste and odor and disinfection by products are of the reasons of color existence in water. The present study was performed using jar apparatus, lime and NaOH as softener agent and for increasing the pH of the process. Alum and ferric chloride coagulants were used to increase the size of flocs in various pH and color removal from water. It was tried to simulate the conditions of water treatment plants. Coagulant and lime doses, initial color and pH were studied. After the process, the residual color, as well as pH and electrical conductivity of water were measured. The results showed a significant increase in color removal with increasing pH. The highest percentage of color removal was 75% using 40mg/L of alum and ferric. The best efficiency of color removal was 86.68% and 94% by 12(g/L) lime for methylene blue and eriochrome black T, respectively. However, during the procedure, the electrical conductivity of water increased.https://ijehse.tums.ac.ir/index.php/jehse/article/view/255https://ijehse.tums.ac.ir/index.php/jehse/article/download/255/254Journal of Environmental Health Science & Engineering73DETERMINATION OF NANOFILTRATION EFFICENCY IN ARSENIC REMOVAL FROM DRINKING WATER273278H.AkbariA.Rashidi MehrabadiA.Torabian20151209Nowadays nanofiltration has been considered for the treatment of organic and inorganic pollutants in surface and groundwater resources. In this study, rejection characteristics of arsenic compounds such as As(III) to form As2O3 and As(V) to form Na2HAsO4.7H2O by a commercial nanofilter NF90 (DOW-FilmTec) was investigated. Arsenic rejection experiments included variations of feed arsenic concentration, transmembrane pressure and pH. In these experiments, as increasing initial concentration As(V) from 120 μg/L to 1026 μg/L in feed water, the percentage of rejection of As(V) decreased from 98.35% to 96.59% (permeate water concentration was 2 μg/L to 35 μg/L) ,while as increasing initial concentration As(III) from 118 μg/L to 985 μg/L in feed water ,the percentage of rejection of As(III) decreased from 94.07% to 87.51% ( permeate water concentration was 7 μg/L to 123 μg/L). Due to increase of pressure from 4 bar to 7 bar, the percentage of rejection of As(V) in finished water increased from 95.68% to 99.02% (permeate water concentration decreased from 21 μg/L to 5 μg/L),while the percentage of rejection of As(III) decreased from 80.99% to 95.11% (permeate water concentration decreased from 96 μg/L to 25μg/L). Also due to increasing pH from 3 to 11, the percentage of rejection of As(V) in finished water increased from 95.45% to 99.00% (permeate water concentration decreased from 22 μg/L to 5 μg/L), while the percentage of rejection of As(III) decreased from 86.6% to 94.81% (permeate water concentration decreased from 65 μg/L to 25 μg/L). Finally, nanofiltration application for arsenic removal from drinking water was recognized suitable regarding its proper efficiency and convenience operation and was recommended for point-of-use applications.https://ijehse.tums.ac.ir/index.php/jehse/article/view/256https://ijehse.tums.ac.ir/index.php/jehse/article/download/256/255