رمضانعلی دیانتی تیلکی

Azo dyes are present in the wastewater of most textile factories, and if they enter water resources, they pose risks to the health of humans and the living environment due to the effects of toxicity, biological accumulation, and mutagenicity. This study aimed to determine the removal of azo dye by a biological method using wastewater treatment plant sludge in aerobic and anaerobic conditions and isolation and identification of bacteria.

This experimental study, was conducted in the faculty of health, at Mazandaran University of Medical Sciences. In this study, the removal of reactive red azo dye 195 in the wastewater of textile factories was investigated using the activated sludge of the wastewater treatment plant. Experiments were carried out in batch mode in both aerobic and anaerobic conditions with 192 samples. The concentrations of azo dye in the range available in the wastewater of textile factories were 50, 65, and 80 mg/liter. The culture medium used in this study was a mineral medium containing glucose. Bottles containing culture medium, sludge, and azo dye were kept at 30°C in an incubator in aerobic and anaerobic conditions for 8 days. The effect of factors including contact time, amount of sludge, and concentration of color was investigated. Sampling was done at the contact times of 1, 2, 4, and 8 days and after centrifuge, the color concentration was measured by spectrophotometric method at a wavelength of 545 nm. The total organic carbon (TOC) concentration of the samples was measured by a TOC analyzer. After removing the color, the bacteria in the bottles were identified by the differential diagnosis method and using special culture media, gram staining techniques, and biochemical tests.

In anaerobic conditions and contact time of 8 days, the removal of azo dye in concentrations of 50 and 80 mg/liter by using 5 ml of biomass was obtained by 93 and 82%, respectively. In the aerobic condition, the removal of the dye was achieved to more than 90% within two days, and after that, the removal efficiency reached 100% with a gently increasing slope up to 8 days. By increasing the concentration of dye from 50 to 80 mg/liter, the removal efficiency decreased by about 10%. Increasing the volume of sludge from 5 to 10 ml in both cases did not have a significant effect on increasing the amount of dye removal. The amount of azo dye removal was higher in aerobic than in anaerobic conditions. In aerobic conditions, for all dye concentrations, the TOC removal rate was about 85-90%. There was no significant difference in the amount of TOC removal for 5 and 10 ml of sludge. The average TOC removal in aerobic was about 10% higher than in anaerobic conditions. In the aerobic condition, the identified bacteria included Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aerogenosa, and in the anaerobic condition, the identified bacterial species were Lactobacillus, Enterococcus faecalis, and Bacillus cereus.

Complete removal of azo dye from textile wastewater by sludge biomass under microaerophilic culture conditions is possible with a contact time of 8 days or more. The dye removal efficiency was higher in partial aerobic than in absolute anaerobic conditions. The identified azo dye-removing bacteria were mainly facultative anaerobic and microaerophilic.

Human health is negatively affected by increase in concentration of carbon dioxide in indoor air due to the lack of proper ventilation. The aim of this study was to remove carbon dioxide from a closed space using sodium hydroxide nanofluid and determining the effect of absorbent concentration, carbon dioxide concentration, and titanium dioxide nanoparticles.

The experiments were conducted in a closed chamber on a laboratory scale. An air suction pump was connected to the absorption reactor and the carbon dioxide measuring device was installed inside the chamber. By injecting carbon dioxide gas inside the chamber, different concentrations in the range of 500, 2000 and 5000 ppm were created. Sodium hydroxide absorbent solution at 0.1, 0.2, and 0.4% were examined. Titanium dioxide nanoparticles (0.008%) and surfactant (0.003%) were used to prepare nanofluids. The absorption fluids’ pH, electrical conductivity, and total inorganic carbon (TIC) were measured before and after carbon dioxide absorption.

By using 0.4% sodium hydroxide solution containing 0.008% titanium dioxide nanoparticles, the carbon dioxide removal efficiency at 500 and 5000 ppm were 72% and 44%, respectively, that were higher than the solution without nanoparticles (20% and 10%, respectively). At 5000 ppm carbon dioxide, increasing the concentration of absorption solution from 0.1 to 0.4% doubled the removal efficiency. The average amount of total inorganic carbon (TIC) in nanofluids increased by about 20% compared to the base fluids. The average reduction of EC in nanofluid was about 25% higher than the base fluid. The average reduction in pH value was less than one unit.

Sodium hydroxide nanofluid containing 0.008% of titanium dioxide nanoparticles is effective in removing carbon dioxide from the air.

Toluene, is usually present in gasoline, thinner, and other petroleum products and is one of the volatile organic compounds that causes air pollution and adverse health effects. The aim of this study was to determine the kinetics of toluene removal from the air by photocatalytic method using foam glass coated with titanium dioxide nanoparticles.

In this experimental study, a glass chamber was used as a closed space. A quartz tube filled by glass foam coated with titanium dioxide nanoparticles was used as air filter. The air filter was placed inside the chamber and an air suction pump was connected to it and a UV lamp was installed next to the air filter. Toluene was injected into the chamber. The contaminated air was passed through the filter and circulated in the chamber. Air samples were taken from the chamber and concentration of toluene was analyzed by Gas Chromatograph.

Brunauer-Emmett-Teller (BET) analysis showed that the average diameter of pores in glass foam was 6 nm and the specific surface area of foam glass was 36 m2/g. The SEM images confirmed coating of titanium dioxide on the surface of glass foam. Toluene removal without UV irradiation was 46%, 40%, and 37%, for 18.5, 37, and 55.5 mg/m3, respectively in 2 hour contact time, but in the presence of UV radiation the toluene removal was 100%, 95%, and 90%, respectively in contact time of 80 min. The kinetics of toluene decomposition was pseudo first order.

Glass foam can be used as a photocatalyst stabilization base to remove BTEX from the air.  This is a suitable method in removing volatile organic compounds from the air in closed spaces.

The aim of this study was to removal of phenol and producing electricity in a microbial fuel cell using the microbial seed of the refinery wastewater.A dual chamber microbial fuel cell having Nafion proton exchange membrane and carbon cloth as anode and cathode was fabricated and operated in batch mode in the incubator at 30°C for a period of 12 weeks. Experiments were conducted in open and closed circuit mode. Anode was put in anaerobic chamber containing minimum growth medium and phenol in the concentration range of 50-1000ppm. Microbial seed from wastewater treatment plant of Tehran Petroleum Refinery was mixed with growth medium and added to anode chamber. Cathode was put in aerobic chamber containing Phosphate buffer. Phenol was analyzed by HPLC and electricity was measured by digital multi meter equipped by data logger. COD was measured by standard method. In all examined phenol concentrations, the maximum time to completely degrade of phenol was 96h. Maximum amount of phenol degradation and electricity generation was occurred in the first 24h of each run. Phenol degradation rate in closed circuit was higher than open circuit mode. The maximum voltage and power generated were 425mV and 36.86mWm-2 respectively. The columbic efficiency of fabricated microbial fuel cell was 5.3 percent and maximum COD removal was 95 percent. By using mixed bacterial of wastewater of oil refinery in a microbial fuel cell, it is possible to remove phenol and generate electricity.

Removal of low concentrations of petroleum hydrocarbons from water by physico-chemical methods encounters many limitations. The aim of this study was thus isolation and identification of bacteria from soils contaminated with total petroleum hydrocarbons (TPH). Removal efficiency of low concentrations of hydrocarbons from water using isolated bacteria was also determined.

TPH concentrations of 100, 500 and 1000 ppm in water were examined. Bacteria were identified and isolated from diesel-contaminated soil. Isolated bacteria were cultured separately in medium containing water with certain concentrations of TPH. At predetermined contact times (2, 5, 7 and 14 days), the total amount of TPH remained in the water was measured using standard methods.

At 100 ppm TPH in water and within 48 hours, the highest removal efficiency of TPH about 65% was obtained by Alkaligenes faecalis. Likewise, the lowest removal performance of TPH, approximately 20%, was obtained by Pseudomonas aeruginosa at this concentration. The highest and lowest removal efficiency of TPH from water at 500 ppm by was achieved by Enterobacter (40%) and Alkaligenes (20%) following 48 h, respectively. At the highest concentration of TPH in water (1000 ppm) and after 48 h, the highest removal rate about 30% was obtained by Enterobacter. for the removal efficiency appeared to increase with the increase of contact time, in which the maximum removal efficiency was about 90% (at 100 and 500 ppm concentrations) and about 50% (at 1000 ppm concentrations) after 14 days.

Bacteria isolated from contaminated soil can be used to remove low concentrations of petroleum compounds from water.

Microbial fuel cell is one of the sustainable development technologies that can be used simultaneously for removal of many pollutants and generate electricity. The aim of this study was to determine the removal rate of high concentrations of phenol in a microbial fuel cell.

A dual chamber microbial fuel cell having Nafion proton exchange membrane and carbon cloth as anode and cathode was fabricated and operated in batch mode in incubator at 30°C for 12 weeks. Anode was put in anaerobic chamber containing minimum growth medium and phenol (50-1000ppm) was added as the sole carbon source. Phenol degrading bacterial seed that was supplied by wastewater treatment plant of Tehran Petroleum Refinery was adapted to phenol and used in anaerobic anode chamber. Cathode was put in aerobic chamber containing phosphate buffer. Concentration of remained phenol in different times was analyzed by HPLC method.

Maximum amount of phenol degradation occurred in the first 24h of each run. Phenol concentrations up to 800 ppm were completely removed during 96 h, but time to complete removal of 1000 ppm phenol was 120h.

By using sludge from wastewater treatment plant of oil refinery adapted to phenol in a microbial fuel cell, it is possible to remove 1000 ppm phenol.

Diazinon is one of the most widely used pesticides in agricultural pest control that pollutes water resources. The aim of this study was to evaluate the adsorption of diazinon from water by zeolite modified with cationic surfactant hexadecyltrimethyl ammonium bromide (HDTMA).

The amount of HDTMA surfactant used to modify the zeolite was one-fold External Cation Exchange Capacity (ECEC) of zeolite (0.53 mmol/g). Modification was performed by contacting zeolite and surfactant for 24h on the shaker. Unmodified and modified zeolite were tested as adsorbent. Experiments were conducted in batch mode in acidic (pH=3), natural (pH=7), and alkaline conditions (pH=11).

The optimal contact times for adsorption of diazinon were 10 and 5 minutes on unmodified zeolite and HDTMA-modified zeolite (HMZ), respectively. According to the Freundlich model, the amount of diazinon absorbed by the HMZ was about 8 times more than that of the unmodified zeolite. By using 1gl-1 of HMZ at pH= 3, the maximum adsorption was 97.6%. Pseudo second order kinetics and Freundlich isotherm model well describes the absorption of diazinon on HMZ.

Modified zeolite has high capacity, so, the method used here, can be used to increase the efficiency of diazinon adsorption in wastewater treatment plants.

Phenol and its derivatives are toxic to all living organism and are found in oil refinery wastewater. Isolation and identification of bacteria from oil refinery wastewater is important to identify aromatic compounds degrading bacteria. The aims of this study were isolation and identification of bacteria from Tehran oil refinery wastewater treatment system and determine amount of phenol degradation by these bacteria.

This experimental study was conducted by using two series of activated sludge samples collected from Tehran oil refinery wastewater treatment plant. Adaptation of bacteria to phenol was done by culturing in growth medium containing phenol at 30°C in incubator. After that isolation and identification of bacteria was done according to standard method. Isolated bacteria were cultured in growth medium containing different concentration (0.5- 1.2gL-1) of Phenol. Bacteria growth was assayed by measuring optical density at 600nm. Concentration of Phenol in the medium growth solution was measured by spectrophotometric method using 4- Amino antipyrine as color reagent at 510 nm.

Pseudomonas, Acintobacter, E.coli, Enterococcus and Enterobacter spps were isolated from oil wastewater treatment plant. Pseudomonas spp. completely removed 0.9gL-1 of Phenol, Acintobacter and E.coli removed 0.7 gL-1, Enterococcus and Enterobacter removed 0.5 gL-1 of Phenol from growth solution. 

Discussion and conculation:

 Pseudomonas spp. isolated from oil refinery wastewater treatment plant has highest phenol removal rate in shorter contact time than other isolated bacteria.

Conventional wastewater treatment systems are not capable of removing phosphorus effectively. The entry of phosphorus into water resources leads to the formation of an Eutrophication phenomenon. One of the methods for phosphorus removal is the use of microalgae. In this way, besides helping with advanced sewage treatment, it can produce algae with many applications. The purpose of this study was to determine the simultaneous and to compare the phosphorus removal (rate of phosphorus) and Spirulina biomass production in a photobioreactor, using two kinds of treated sewage. The experiments were carried out with the manufacture of a photobioreactor and air injection by means of a fine bubble diffuser into sewage-containing reactors. The light source in this test was designed as fluorescent light bulbs and alternating radiation. Urban wastewater effluent and refined sewage were used as a culture medium in a photobioreactor. The amount of phosphorus in the purified sewage was measured by spectrophotometry at a wavelength of 690nm. The phosphorus removal and algal biomass production were measured in different culture medium containing wastewater with various concentrations of phosphorus. The initial concentrations of phosphorus in refined urban sewage and sanitary sewage were 1.96 and 0.4mg L-1, respectively. Phosphorus removal during microalgae cultivation with municipal wastewater and sanitary sewerage (removal of phosphorus) for 8 days, was 71.9% and 37%, respectively. Biomass production in this time were 0.18 and 0.025g/l, respectively. By decreasing the concentration of phosphorus in the wastewater, the amount of biomass production and (removal of) phosphorus removal decreased. Treated domestic and sanitary sewage can be injected directly, without prior treatment, in photobioreactor and it is possible to remove phosphorus and to produce algal biomass.

CO2 is the main cause of greenhouse effect. Previous studies have shown that CO2 in methane and coal flue gas can lead to microalgae growth. The aim of this research was to study the CO2 biofixation by Spirulina and injecting kerosene flue gas. A photo bioreactor was fabricated in which kerosene flue gas and air were separately injected. The photo bioreactor was filled by growth medium without carbon source. Light source was four fluorescent lamps (10 Klux intensity) operated in continuous and intermittent modes. The concentration of CO2 was chosen in the range of 580 to 6000 ppm that was measured by NDIR CO2 detector. The initial concentration of algae was 20 mgL-1. The algal biomass production was measured during the experiment. The maximum production of algae by air and kerosene flue gas containing 5500 ppm CO2 using artificial intermittent light was 0.07 and 0.41 gL-1 d-1 and maximum concentrations of biomass were 0.25 and 1.63 gL-1, respectively. CO2 biofixation rates were between 2.27% and 4.03% at different runs. Biomass productivity with intermittent light was 15% less than continuous light and it reached 1.91 gL-1 with 5500 ppm CO2 using continuous light. In this study, the ability of a photo bioreactor was confirmed in the removal of CO2. Also, increase in CO2 contributes to increase in biomass production.

Introduction and purpose: Groundwaters provide the main source of drinking water in Mazandaran province; however, the high concentration of soluble salts and hardness in these waters result in probable sedimentation and corrosion in water distribution systems of these areas. Therefore, the aim of this study was to determine the sedimentation and corrosion potential in the drinking water resources in Amol, Babol, Ghaemshahr, Sari, and Neka in the second and first halves of 2015 and 2016, respectively. A total of 192 water samples from selected cities of Mazandaran province were tested using determining parameters of sedimentation and corrosion indices by a standard method. The indices, such as Langelier saturation, Ryznar stability, Puckorius scaling, Aggressive, and Larson-Skold were determined using relevant data. The results of the study showed that out of 192 analyzed samples in the surveyed cities, 76 and 81.3 % of them had the sedimentation propertiesand potentials considering Ryznar stability and Langelier saturation indices, respectively. With regard to Puckorius scaling index, sedimentation potential was observed in 68.8 % of water samples. Aggressive and Larson-Skold indices have also showed sedimentation properties of water. It can be concluded that the drinking water in the water distribution systems of these cities has relatively sedimentation properties.

The aim of this study was to determine the amount of carbon dioxide uptake and biomass production in a photo bioreactor containing Spirulina microalgae as growth medium by injecting the products of natural gas combustion. A photo bioreactor was fabricated and combustion products of natural gas as well as air were injected by separate diffusers. The photo bioreactor was filled by growth medium without carbon source. In the control and test reactors, carbon dioxide was supplied by air and flue gas, respectively. Light source was natural and artificial. Artificial light source was four fluorescent lamps having 10 Klux intensity, which were operated in continuous and intermittent modes. The concentration of carbon dioxide entering in the test reactor was chosen in the range of 580 to 5000 ppm. The concentration of carbon dioxide in the inlet and outlet gas of the reactor was measured by a carbon dioxide detector equipped with NDIR. The algal biomass production and also changes in pH were measured. The flue gas was used as such without any scrubbing or desulfurization. The maximum production of algae using air and combustion products of natural gas having 4100 and 3300 ppm carbon dioxide using artificial intermittent light was 0.07 and 0.2 gL-1 d-1, respectively. Moreover, the maximum concentration of biomass was 0.25 and 1.04 gL-1, respectively. Carbon dioxide biofixation rate was 2.5 and 3.3% in the 3300 and 4100 ppm carbon dioxide runs. Natural gas combustion products can be injected in the photo bioreactor directly and without prior treatment, and it is possible to remove carbon dioxide and produce algae. Biomass productivity with intermittent light was 35% less than continuous light. With the increasing concentration of carbon dioxide in the combustion gas, algal biomass production increased.

Background and Chromium hexavalent compounds are carcinogens that are found in groundwater as chromate and dichromate negative ions. The aim of this study was to remove Cr (VI) from water by activated carbon modified with cationic surfactant alkyl dimethyl benzyl ammonium chloride (Benzalkonium chloride).
In terms of the Critical Micelle Concentration (CMC) of surfactant, three concentrations of Benzalkonium Chloride (BZK) including half, one and two fold of CMC were used to modify activated carbon. Modification was performed by contacting activated carbon and surfactant for 24h on the shaker. Ordinary and modified activated carbons were used as sorbents for Cr(VI) removal from aqeoues solutions. Modified Activated Carbon (MAC) by cationic surfactant and Unmodified Activated Carbon (UAC) were examined as adsorbents for Cr (VI) from aqueous solutions. Experiments were conducted in batch and continuous mode in acid (pH=4), natural (pH=7) and alkaline conditions (pH=10). Cr (VI) was measured by spectrophotometer.
Time to reach Cr (VI) adsorption equilibrium for UAC and MAC were 180 and 120 min, respectively. Cr (VI) adsorption capacity for UAC was 1.79 mg/g but in MAC the value increased to 8.87 mg/g. 5g/L of MAC modified with 2cmc of surfactant showed greatest Cr (VI) adsorption capacity in natural pH condition. Breakthrough point in the column packed with MAC enhanced 3 times compared with UAC. Adsorption isotherm was best fitted with Langmuir model and adsorption kinetics was determined as pseudo second order.
Modification of activated carbon by cationic surfactant causes increase in adsorption capacity of Cr (VI) from aqueous solution. Therefore, it could be used in removal of toxic Cr (VI) compounds from water.

Background and Due to inadequate quantity and low quality of water resources in rural regions of Gomishan (Golestan province), local residents use cisterns for household water. Therefore, it is necessary to investigate the hygienic situation of these cisterns.
In this study, water samples were obtained from 31 villages using random sampling (two times; total number of samples=406). Bacteriological tests were carried out by standard methods. The relationship between hygienic situation of cisterns and bacteriological quality of water were statistically analyzed.
A total of 406 water samples was examined by measuring total coliform and fecal coliform, in which. 94 samples (23.14%) showed total coliform and 28 sample (6.89%) showed fecal coliform. A significant relationship was observed between hygienic status of cisterns and bacteriological pollution (P Microbial contamination in the studied cisterns calls for sanitizing the cistern in the region and changing the drinking water resources.

Background and Nitrite and nitrate are considered as pollutant agents of ground water resources that cause several hygienic complications. Agricultural fertilizers that contain nitrate are widely used in north of Iran. This study was carried out to determine the concentrations of nitrite and nitrate in agricultural and drinking water wells in rural areas in Miandoroud, Iran. In this study, 276 samples were collected from 35 drinking water wells in Miandoroud (Mazandaran province, north of Iran) in March-September 2013. All experiments were performed according to the standard methods examination book. The results were analyzed in SPSS V.16 and Microsoft Excel. In this study, 276 samples were collected from 36 drinking water and agricultuer wells in Miandoroud (Mazandaran province, north of Iran) in March-September 2013. All experiments were performed according to the standard methods examination book. The results were analyzed in Microsoft Excel. According to the results, the concentration of nitrite was within standard levels established by national guidelines, while in some regions the nitrate concentration was found to be higher than standard levels. In all wells gradual increases were seen in nitrate concentrations. There was a direct relationship between nitrite and nitrate concentrations with depth and temperature. The nitrate concentrations in some wells were higher than standard levels, therefore, more attention should be paid to nitrate pollution in this region.

4-chlorophenolisone of the phenol derivatives that enters the environment from various sources. 4-chlrophenol ranks the primary pollutant agent. This study evaluated the efficiency and kinetics of photocatalytic degradation of 4-chlorophenol from aqueous solutions by sunlight and zinc oxide nanoparticles.

This is an empirical study and Experiments were performed in the batch system. Determined dosage of ZnO nanoparticles was added to 4-chlorophenol solution (25-200ppm) and samples were allocated under the sunlight during midday hours in summer. Effects of parameters such as ZnO loading، pH، contact time and initial concentration of the polluter 4-chlrophenol were investigated. The remaining concentrations of 4-chlorophenol were analyzed using HPLC. Removal of total organic carbon was measured by TOC analyzer.

The results showed that removal efficiency of 4-chlorophenol was achieved 72%in presence of solar energy as means of energy source at both neutral and alkaline pH and catalyst dosage of 1. 5grL-1. Efficiency increased as increasing pH and contact time. The photocatalytic degradation of 4-chlrophenol was best fitted with Langmuir–Hinshelwood model، and can be described by pseudo-first order kinetic.

In general، 4-chlorophenols can be significantly degraded from aqueous solution by using sunlight as the energy source for the reaction and nano-sized zinc oxide as catalyst.

Background and Natural Organic Matter (NOM) is precursor of disinfection by-products (DBPs) during chlorination, so removal of NOM from drinking water resources is a necessary task. Due to organophilic properties, Surfactant Modified Zeolite (SMZ) can adsorb more NOM. The aim of this study was to determine and compare the efficiency of NZ and SMZ in removal of Dissolved Organic Carbon (DOC) from water. Modification of zeolite was performed using Alkyl Dimethyl Benzyl Ammonium Chloride (ADBAC) as organophilic compound. Natural zeolite was added to 10% concentration of ADBAC solutions, then, the mixture was shaken for 24 h. Modified zeolite was washed several times with distilled water. Solutions containing various concentration of natural organic matter were contacted with NZ and SMZ for 48 h. The effects of parameters such as initial DOC concentration, solution pH and adsorbent dose were examined. Measurement of dissolved organic matter was performed by TOC (Shimadzu-5000) analyzer. By increasing the sorbent dose, the amount of adsorbed DOC was increased. In the natural pH condition, the amount of DOC adsorption by 20 gL-1 of NZ and SMZ was 33% and 65%, respectively. By increasing the concentration of DOC the adsorption capacity increased. The best fitted model for NZ and SMZ were Freundlich and Langmuir, respectively. Cationic surfactant modified zeolite could increase the adsorption of DOC from water.

Background and Up to now various methods has been considered for removing heavy metals such as pb from aqueous solution including using agricultural wastes as low cost adsorbent. The purpose of this study was efficiency evaluation of natural (crude) and citric acid modified rice straw for removal of pb from aqueous solutions. This study was performed at laboratory scale and batch system. We studied the influence of process variables such as pH, contact time, pb concentration and adsorbent dosage. Data from equilibrium study were modeled using isotherm and kinetic models. The concentration of pb was measured by atomic adsorption. Data was then analyzed using ANOVA test. Experimental results showed that the optimum pH and equilibrium time for pb by natural and modified rice straw was 6 and 120 minute, respectively. Removal of pb increased in both adsorbent dosages by increase in pb concentration up to 10 mg/l and increasing the dosage of adsorbents. Adsorption isotherm fitted Temkin model but adsorption kinetic followed pseudo second order. The efficiency of natural rice straw and modified rice straw in removal of pb was 85 and 99%, respectively. According to the results, rice straw especially the modified one could be used as a suitable, low cost and efficient adsorbent for removal of pb from aqueous solutions.

The presence of phenol in water and wastewater, due to its toxic threat to human life and environment, is a major concern. The purpose of this study was to investigate the rate of phenol adsorption by modified Azolla and Canola. This study was conducted at laboratory scale. In this study the effect of various parameters on adsorption performance was investigated and isotherms and kenitics adsorption were determined. In order to measure the specific surface area of absorbents the BET isotherm technique was carried out. The concentration of phenol in samples was measured by HPLC instrument. Removal efficiency increased with increase of adsorbent dose and contact time and decrease of the initial concentration of phenol. Optimal phenol removal was obtained at pH =3, adsorbent dose of 10 g/L and contact time of 90 and 120 min for Azolla and Canola biomass respectively. Coefficients showed that the best isotherms for Azolla and Canola adsorbents are Langmuier and Freundlich respectively. The reaction rate for both adsorbents agrees with the pseudo-second order kenitics model. Based on the Langmuier model, the maximum adsorption capacities were calculated to be 11.2 and 9.4 mg/g for Azolla and Canola biomasses respectively. According to the obtained results, Azolla and Canola biomass can be used as efficient and cost-effective adsorbents for treatment of industrial effluents.

Background and Adsorption processes are widely used in removing pollutants from waste waters، particularly those that are not easily biodegradable such as dyes. In this study natural zeolite، which is easily found in many places، was used as a low-cost adsorbent for removal of dye from effluents. Adsorption of Azo dyes including two basic and one reactive (Reactive Red 198(RR-198)، Cationic Red GTL (BR-18) and Cationic Red GRL (BR-46)) were studied by natural zeolite clinoptilolite. In batch experiments we evaluated sorbent dose، contact time، concentration of dyes and ph. The adsorption isotherm was also determined using the adsorption data. Kinetics of dye adsorption by zeolite was also studied. The remaining concentration of dyes was measured by spectrophotometer. Increase in sorbent dose and contact time increased adsorption rate. Optimal contact times for BR-18، RR-198 and BR-46 were 90، 90 and 120 minutes، respectively. By increasing the sorbent does for basice dyes، adsorption efficiency increased up to 99 percent. The best pH for basic dyes was found to be 9. The adsorption rate increased by decrease in dye concentration. It was found that adsorption isotherms for the examined three dyes fitted to the Langmuir isotherm. The kinetic studies indicated that the adsorption for dyes followed the pseudo-second-order. Results indicate that clinoptilolite has good adsorption capacity for basic dyes. Natural zeolite is found easily in many places and could be used as acceptable and affordable for decontamination applications.

Background and Bisphenol A is a harmful organic compound which is either used or produced in various industries. This compound is resistant to biodegradation. The aim of this study was to determine the photocatalytic degradation of Bisphenol A from aqueous solutions by ZnO nanoparticles. In this experimental study the morphology of nanoparticles was characterized using scanning electron microscope. The volume of sample was determined by Rotatable inscribed Central Composite design (CCD) method. The samples were separately placed under UV radiation in defined amount of nanoparticles and initial concentration of bisphenol A at different operating conditions. The concentrations of bisphenol A were analyzed by UV Spectrophotometer. Data was then analyzed in Minitab V.16. The degradation efficiency of bisphenol A increased when the pH, contact time and loading nanoparticles increased and the concentration of bisphenol decreased. Efficiency of ZnO was found to be better at alkaline pH than acidic conditions. UV/ZnO process was capable of removing bisphenol A to 97%. This study showed that photocatalytic degradation by ZnO nanoparticles in presence of UV is an effective method for removal of bisphenol A.

Background and Nitrate is probably the most widespread groundwater contaminant in the world, due to its high water solubility. It imposes a serious threat to human health and contributes to eutrophication. The objectives of this study were set to explore how the factors of ultraviolet light and ionic strength could influence the nano zero valent iron (NZVI) system for nitrate removal. In this study, response surface methodology was employed for the design and analysis of experiments. Experiments were carried out as per Box–Behnken) BBD) surface statistical design with four input parameters namely NZVI dose (0.5–2g/L), initial concentration (50–150mg/L), contact time (15–60min), and ionic strength (1000-5000μmho/cm). All experiments were performed in the presence and absence of UV irradiation. The Maximum reduction efficiency for experiments in the presence and absence of UV irradiation was 85.3% and 91.6% in nano zero valent iron dose 2g/L, initial concentration 100mg/L, Contact time 60, and ionic strength 3000μmho/cm. The proposed model was essentially in accordance with the experimental case with correlation coefficient R2 = 0.9992, 0.9946 and Adj-R2 = 0.9982, 0.9884, respectively. Removal efficiency of nitrate increased with increase in time and NZVI dosage. In contrast, it decreased when ionic strength and initial concentration increased. Also, UV irradiation accelerated the removal of nitrate.

Background and

The presence of phenol and its derivatives in water and wastewater are of major concern because of their toxicity and threat to human life and environment. The aim of this study was determination of the modified lemna minor and azolla in phenol adsorption.

In this emperical-lab study, the washed lemna minor and azolla was used as adsorbents. The effect of vatious parameters on adsorbents performance was investigated. The concentration of phenol was measured by high-performance liquid chromatography (HPLC). Also, data were fitted with variety isotherm and kinetic models.

The phenol adsorption rate increased by increasing of contact time and adsorbent dose in both adsorbents; however, the phenol adsorption per each gram of adsorbents (qe) decreased. The adsorption efficieny increased by decreasing intial phenol concentration. With increasing of solution pH, removal efficiency decreased and optimum pH was 3. Adsorption isotherm data showed that the phenol sorption followed the Langmuir. Kinetics of sorption was well described by pseudo-second order model.

The lemna minor and azolla can be used as effective and low-cost adsorbents to organic compounds removal from industrial effluents. Although due to adventages such as more plenty and higher ability in phenol removal, the azolla is the best adsorbnet.

Background and

Analysis, monitoring and control of water quality, including water and sanitation and health care are the duties of companies. Because of the quality of drinking water, a comprehensive research was carried out in Savadkooh, Iran, in this study.

Data of Water and Sewage Company of Savadkooh were analyzed during 2010 and 2011. Water samples were seasonal (chemical) and month (biological) sources water in Alasht Spring by Halli Khamen Spring and a well and two reservoirs in Zirab Spring, Golnab Valleys and wells No. 4 and 5 as well as their reservoir, and in Shirgah were wells No. 1 and 4 and 5 and the water reservoir and springs Golnab valleys in Polsefid by Flord Spring and water and sewage company of Savadkooh repository which were analyzed in the laboratory.

In Polsefid, the mean total hardness, mean electrical conductivity and the average pH were 173 mgCaco3/l, 359 µS/cm, and 7.8, respectively. The amounts were 168 mgCaco3/l, 286 µS/cm, and 8 in Zirab, 184 mgCaco3/l, 344 µS/cm and 7.8 in Shirgah, and 172 mgCaco3/l, 333 µS/cm and 7.9 in Alasht, respectively. In Polsefid, 87% of samples in 2010 and 85% in 2011, in Zirab, 91% of the samples in 2010 and 100% in 2011, in Shirgah and Alasht, all the samples in 2011 and 2012 were coliform-free. Nitrite and nitrate levels in all water samples in were lower than standard and in acceptable level. In all samples, residual chlorine was at optimal level, and the amount of fluoride was less than desirable.

Hardness of all the cities water were described as moderate and acceptable. The electrical conductivity of the water in all areas was desirable. The pH of water samples in all the cities were within acceptable limits. The amount of fluoride in the water samples was well below so that it requires to be taken into consideration.

Arsenic contamination of water resources is a global problem. Drinking of arsenic-rich water over a long period results in various health effects including skin problems، skin cancer، cancers of the bladder، kidney and lung، and diseases of the blood vessels، and possibly diabetes، high blood pressure and reproductive disorders. Carbon nanotubes (CNTS) in the field of nanotechnology، as a new adsorbents were investigated in several studies. In this research، optimization of As (V) removal from aqueous solutions by Single-walled Cabon، investigated.

Carbon nanotubes Carbon was prepared from Research Institute of Iran''s oil industry. Initially the carbon nano tubes was Functionalized by nitric acid. Experiments based on the response surface methodology was designed. Test data assessment by using the software Minitab 16، Excel 2007، and regression، correlation and analysis of variance was performed.

In this study، increasing the amount of adsorbent، contact time، initial concentration and decreasing pH on arsenate removal efficiency was affected. Maximum capacity of arsenate adsorption by carbon nanotubes equal to 8. 84 mg/g. Arsenate removal percentage increased with decreasing pH and increasing of concentrations of arsenate and absorbent value.

The model with the highest coefficient (R2) ration predicted (Predicted R2) 95/01 and 72/25for carbon single-wall carbon nano tubes by nitric acid was estimated with the maximum percentage for arsenate removal of65%and a maximum capacity8/48. Using response surface، the optimal conditions (PH = 3-6 and the absorption of 150 mg/l in sample volume (100ml) Was provided، respectively