[Quality zoning of seasonal changes in nitrate and ammonia in drinking water wells of Babol city using GIS system]

Background: Underground water resources constitute an important part of urban water resources. One of the serious challenges in ensuring and promoting community health is gradual increase in nitrate levels of drinking water of communities across the world. The purpose of this study was to investigate the seasonal variation of nitrate and ammonia levels in drinking water wells of Babol city using GIS software, in 2010-11.

Materials and Methods: This cross-sectional analytical study was performed on drinking water wells of Babol city in 2010-11. Sampling was done according to a standard method from 20 drinking water wells, in different seasons; and in final, 80 water samples were analyzed. Nitrate and ammonia concentration of samples was measured using Spectrophotometer DR2000 [Hach company] in 500 and 425 nm, respectively. For qualitative analysis and seasonal fluctuation of nitrate and ammonia concentration of different areas, Geographic information systems, ArcGIS, was used.

Results: The results showed that the highest amount of nitrate was in summer [23.68 mg/l], and the lowest was in winter [14 mg/l]. While the highest and the lowest amount of ammonia was in spring [0.43 mg/l] and summer [0.06 mg/l], respectively. Also, the results showed that only in well number 5 located in Kate Sofla village, nitrate concentration had increasing trend, and in the remaining wells, nitrate and ammonia concentration, had an increasing and a decreasing trend, respectively.

Conclusion: The results indicate that nitrate and ammonia levels in all samples were lower than the WHO recommendations. To avoid increasing in the ammonia and nitrate concentrations in the underground waters, ongoing training to farmers on the proper use of chemical fertilizers, as well as the construction and operation of wastewater collection systems are recommended.

Fluoride concentration in potable groundwater in rural areas of Khaf city, Razavi Khorasan province, northeastern Iran

Long-term exposure to high concentrations of fluoride is associated with several adverse effects on human including dental and skeletal fluorosis. We studied all the groundwater wells located in rural areas of Khaf city, Razavi Province, northeastern Iran between 2009 and 2010. Fluoride concentration of water samples was measured by SPADNS method. We found that in rural areas the fluoride concentration ranged from 0.11 to 3.59 ppm-the level was less than the permissible limit in 31% of studied samples, higher than the permissible limit in 4% of the samples, and within the optimum limit of 1 to 1.5 ppm in 65% of water samples

[ process of coagulation, flocculation and advanced oxidation in effluent treatment of second refinery oil industries]

One of the industries dependent on oil compounds that play an important role in economy, preserve resources and oil reserves, as well as environmental protection is the secondary refinery Oil industries. The efficiency of Coagulation, flocculation and advanced oxidation process in the Effluent treatment industry was studied. This study is a descriptive- quasi-experimental that effluent pollution quality measured with COD. Physicochemical processes of coagulation, flocculation, by using conventional coagulants and oxidation with ozone for the removal to access environmental discharge effluent standards were studied. Coagulants such as aluminum sulfate, ferric chloride, sodium silicate, poly aluminum chloride were evaluated. Jartest was used to determine the efficiency of coagulation and flocculation. Samples were collected from Salafchegan industrial district in Qom. Examination methods were extracted from Standard methods for water and wastewater examination. Initial experiments showed that BOD, indicating biological treatment wastewater, in comparison with COD, indicating chemical oxygen demand of wastewater is very low. Thus, the application of biological processes of effluent treatment without using chemical processes, not performance and not economic. The experiment showed that the amount of COD in raw effluent was varied from 38000 to 78000mg/l. Using advanced oxidation with O[3] in pH=11.5 can reach 77.5% and in pH=9 in 57.2 and in pH=3.25 in 21.3 COD removal efficiency respectively. According to the results, advanced oxidation process prior to biological effluent treatment of the second refinery oil industries is effective in eliminating pollutants and toxic substances

[Investigating the efficiency of ultraviolet irradiation for inactivation of free living nematodes in water]

Free living nematodes due to their active movement and resistance to chlorination; don't remove in conventional water treatment processes thus can be entered to distribution systems and cause adverse health effects. UV irradiation can be used as a method of inactivating these organisms. This study is done to investigate the effect of ultraviolet lamp on inactivation of free living nematode [Rhabitidae] in water. The effects of duration of irradiation, turbidity, temperature, UV dose and pH are investigated in this study. Ultraviolet lamp used in this study was a 11 watt lamp with intensity of 24 micro w / cm[2]. Contact time required to achieve 100% efficiency for larvae nematodes and adults were 9 and 10 minutes, respectively. Increase of turbidity up to 25 NTU decreased inactivation efficiency of larvae and adult nematodes from 100% to 66% and 100% to 64%, respectively. Change in pH ranged from 6 to 9 did not affect the efficiency of inactivation. With increasing temperature inactivation rate increased. The results showed that there was a significant correlation between the increase in contact time, temperature rise and turbidity reduction with inactivation efficiency of lamp]p<0.001[. Also the effect of the lamp on inactivation of larvae nematode was more than the adults

[Application of dry activated sludge for lead and cadmium adsorption: isotherm and kinetic modeling]

Heavy metals have an important role on organism life and their high concentration may be a great threat for humans and other organisms' lives. Up to now, various methods have been used for the removal of these metals, which include the adsorption process. The aim of this study was the recovery of municipal disposals, and using as absorbent for lead and cadmium removal from aqueous solutions. Adsorption of lead and cadmium on dry activated sludge was investigated. Activated sludge was obtained from diary industry [Tehran]. All experiments were performed in batch system on 202 synthetic samples to investigate the effects of pH, contact time initial concentration lead and cadmium and adsorbent dose. The most conventional adsorption and kinetic models were applied to describe metal adsorption and dynamic reaction. The results showed that with increasing of adsorbent doses, contact time and pH solution, lead and cadmium removal efficiency increased. The maximum lead and cadmium adsorption was obtained at pH: 6 and an equivalent time of 180 min. With increasing initial concentration of lead and cadmium, removal efficiency decreased. The obtained results in this study were matched with langmuir 2 isotherm [R[2]>0.99] and interparticle diffusion kinetic [R[2]>0.94]. Maximum adsorption capacity of lead and cadmium on dry activated sludge was obtained to be 2.66 and 1.66mg/g, respectively. Maximum constant rate of lead and cadmium was 0.045 and 0.041mg/g.min[0.5], respectively. According to the results, dry activated sludge is recommended as a low cost and available adsorbent to remove lead and cadmium from aqueous solutions

Evaluation of [222]Rn rate in medical dormitory of Kerman city

Radon [[222]Rn] Measurement in the residential environments is very important because of its effecting on human health and causing cancer in the respiratory system. [222]Rn is individually responsible for half of the natural radiation received in humans and influences on human by breathing. Hence, this study was undertaken to access the [222]Rn level in the dormitories of Kerman university of medical science [southeast of Iran] to ensure its safety level. In this study, for measuring [222]Rn level in seven dormitories of the Kerman University of Medical Sciences, the Lucas cell technique was used. This study was undertaken during the winter because of the high concentration of radon in this season due to closed building ambience. In this study, the highest measured radon gas rate was 24.5 Bq/m[3] in Boustan [1]. Average concentrations of the radon gas in all dormitories were 4.7 Bq/m[3], which is lower than the standard level. The results of this study showed that the [222]Rn level in all dormitories was lower than the normal amount [48 Bq/m3] as well as the standard level

Field efficacy of expanded polystyrene and shredded waste polystyrene beads for mosquito control in artificial pools and field trials, Islamic Republic of Iran

Concerns about traditional chemical pesticides has led to increasing research into novel mosquito control methods. This study compared the effectiveness of 2 different types of polystyrene beads for control of mosquito larvae in south-east Islamic Republic of Iran. Simulated field trials were done in artificial pools and field trials were carried out in 2 villages in an indigenous malaria area using WHO-recommended methods. Application of expanded polystyrene beads or shredded, waste polystyrene chips to pool surfaces produced a significant difference between pre-treatment and post-treatment density of mosquitoes [86% and 78% reduction respectively 2 weeks after treatment]. There was no significant difference between the efficacy of the 2 types of material. The use of polystyrene beads as a component of integrated vector management with other supportive measures could assist in the control of mosquito-borne diseases in the Islamic Republic of Iran and neighbouring countries

Investigation of indirect contact freezing process in desalination of boshehr beach's saline water

Nowadays, most countries of the world have shortage of water due to many reasons such as population growth, rising of living standards, indiscriminate water use, and so on. Besides, in absence of adequate water resources, desalination of brackish and saline waters have been used to supply potable water. Freezing process is one of the methods which can be used to desalinate saline waters.The aim of this study was to survey freezing process to produce potable water from saline water of Persian Gulf shores. This study was conducted in lab-scale by using indirect contact freezing. Three samples of 50 liter were provided from Bushehr shores. The implemented process steps were freezing [crystallization], separation of crystals, surface washing, and thawing. Freezing of the samples [each in 0.5 liter containers] were performed by a refrigerator at -20°C and 0.1KW/h energy consumption. The removal efficiencies of TDS in the first, second, and third samples by first freezing process were 56, 56, and 51 percent, respectively. Moreover, the removal efficiencies by EC were 42, 44, and 40 percent, respectively. Meanwhile, the removal efficiencies of TDS in first, second, and third samples by second freezing process observed 69, 69, and 68 percent, respectively. Moreover, the removal efficiencies by EC were 61, 60. and 63 percent, respectively. Also, the removal efficiencies of TDS in first, second, and third samples by third freezing process were 72, 73, and 72 percent, respectively. Moreover, the removal efficiencies by EC were 77, 78, and 77 percent, respectively. The production of the potable water by this method was 15-20 percent of the entry water. According to the obtained results, potable water was obtained after third freezing of the saline water. Meanwhile, TDS of the produced water was less than maximum allowed concentration of Iranian standards

Study of nitrate reduction from water using nanosized iron

New studies indicate that nitrate concentration in groundwater is increasing in most cities. High concentrations of nitrate in water increase the potential health risk in the community and the environment. In infants, No[3-] is reduced to No[2-], which combines with hemoglobin in the blood to form met hemoglobin leading to blue-tinged blood for babies under six months old in particular, Namely, so-called [blue baby syndrome] and it also produce carcinogenic compounds. Therefore high nitrate concentration is important. The aim of the present study is removing nitrate from water using zero valent iron. Analyses were conducted on synthetic samples. These samples were analyzed considering reaction times, pH, initial nitrate and sulfate concentration. Results showed that at Nitrate with an initial concentration of 200mg L[1-] after 60 min of reaction at pH [s] 7, 6 and 5 about 67.8%, 72.5% and 88% was reduced, respectively in concentration of 100 and 300 mgL [pHN6] the removal efficiency is 60 and 83 percent, respectively. In sodium sulfate and nitrate with concentration of 300, the removal efficiency reached from 72 to 70 percent. Results show that the initial pH is important to achieve maximum efficiency of nitrate removal. So the lower pH levels increases removal efficiency of nitrate. All of the experiments indicated that removal is the highest in the first 5 min. Generally with an increasing initial nitrate concentration the removal efficiency of nitrate increases

[Cadmium adsorption by a bacterial biofilm supported on clinoptilolite from aqueous solution]

Heavy metals pollution represents a serious problem for human health and for life in general and bacterial biofilms are able to adsorb heavy metals from dilute aqueous solutions and accumulate them within their cell structure. The aim of this study was to investigate the ability of Escherichia coli biofilm [an effective agent for metal adsorption] supported on clinoptilolite for the removal of cadmium from aqueous solutions. Adsorption experiments were carried out in a laboratoryscale batch model with clinoptilolite alone and clinoptilolite covered by a bacterial biofilm. The effects of initial heavy metal concentrations, pH, and agitation time on the removal efficiency were studied. Finally, experimental results were analyzed using isotherm equations. The results of this study revealed that cadmium adsorption to clinoptilolite was lower than that of clinoptilolite covered by biofilm and adsorption of the cadmium was influenced by several parameters such as initial concentration of cadmium, biosorption time and solution pH. The uptake values for clinoptilolite and for clinoptilolite covered by biofilm were 6.8 mg/g and 9.6 mg/g respectively in the batch model, for initial cadmium concentrations of 25 and 100 mg/L. It was also observed that as the initial cadmium concentration increased, the uptake increased, but the removal rate decreased. Maximum adsorption efficiency was achieved at pH value of 6. The biosorption equilibrium for cadmium was best described by the Freundlich and Longmuir models. It is concluded that the presence of biofilm increased the uptake efficiency of clinoptilolite and the biofilm tested in our study seems very promising for the removal of cadmium from aqueous solution

Effect of fenton process [H[2]O[2] / Fe[2+]] on removal of linear alkylbenzene sulfonate using central composite

This study investigates the degradation of Linear Alkylbenzene Sulfonate [LAS] in aqueous solution using Fenton's process in a batch reactor [at pH = 3 and 25 Degree C]. Experiments were carried out to survey the effects of the amounts of ferrous sulfate [FeSO[4].7H[2]O] and hydrogen peroxide [H[2]O[2]] on the LAS and COD removal. Central composite design and response surface methods were used to optimize the Fenton oxidation process through examination of three independent operating variables namely oxidant dose [H[2]O[2]], catalyst dose [Fe[+2]] and reaction time., hydrogen peroxide dose ranging from 150 to 750 mg /L and Fe[+2] concentration in the range of 10 -130 mg /L were selected to be examined at different reaction times between 20 and 80 minutes. Models were developed and results shows that the oxidation capacities of H[2]O[2] /Fe[+2] were highly dependent on the concentration of H[2]O[2] and Fe[+2]. Satisfactory decay rates of LAS to lock up biodegradable concentration level were obtained, and in the case for oxidation of 200 mg /L LAS, the optimum values were achieved at 600 and 130 mg/L for H[2]O[2] and Fe[+2], respectively

Efficiency of calcium and magnesium removal by nanofiltration membrane from synthetic water under different operating conditions

There are various techniques for reduction or removal of hardness of water each with its own special advantages and disadvantages. Nanofiltration, process due to its simplicity and efficiently, has gained a great attention and is used for removal of various ions and organic matters. The aim of this study was to investigate the evaluation of efficiency of calcium and magnesium removal by a nanofiltration membrane from synthetic water under different operating conditions. This study was performed in laboratory scale using a commercial NF membrane similar to pilot scale. NF experiments were conducted using a calcium initial concentrations [280, 300, 320, 340 and 360 mg/L] and magnesium initial concentrations [60, 80, 100, 120 and 140 mg/L] with flow rate of 0.4 L/min [Qi] and 0.8 L/min [Q[2]]. To investigate the removal of calcium and magnesium as a function of co-existing anions and cations for NF membrane, sodium, potassium, calcium and magnesium ions [as cation] and chloride, nitrate and sulfate ions [as anion] were chosen. The results revealed that with the increase in initial calcium and magnesium concentration, the removal efficiency decreased, with increasing initial calcium concentration from 280 mg/L to 360 mg/L, the removal efficiency decreased from 69.08% to 61.25%, respectively and magnesium removal efficiency declined from 70.05% to 62.25% with increasing concentration from 60 mg/L to 140 mg/L, respectively. In addition, while flow rate varied from 0.4 L/min to 0.8 L/min, calcium and magnesium removal efficiency descended to approximately 5%. Most effectiveness due to anions and cations with calcium and magnesium were related to sulfate and divalent cations and chloride and sodium lowest effectiveness related to choride anion and sodium cation respectively. According to the results, nanofiltration process was applied as efficient and proper method for hardness [calcium and magnesium] removal from water

Determination of Pb,Cd,Cr and Ni concentration in Imported Indian Rice to Iran

Heavy metal pollution has always been a major cause contamination of environment and considered as a major concern for food health. Rice is the most popular food among Iranians and presence of heavy metals in trace level in rice has received special attention because they are directly related to health. The aim of this research was to investigate the concentration of Pb, Cd, Cr, Ni in rice prevalent in the market of Iran. 20 of the most widely consumed brands of Iranian rice were purchased from local market in Iran. 3 samples of each brand were collected and certain volumes of each sample were digested with acid. Heavy metal contents in the digested samples were determined by atomic absorption spectrometry. The results showed that mean concentration Pb, Cr, Ni in rice samples respectively was 0.387, 0.683, 0.019 [mg/kg]. Notably the Ni and Cr content in the rice samples was found to be below the food sanitary standards in India rice. In the other hand 50% samples content Pb was found to be upper the food sanitary [Pb: 0.3 mg/kg]. The result indicated that weekly intake of heavy metal by rice was below the provisional tolerable weekly intake recommended by WHO/FAO. However, risk assessments needs considerable attention and better prevention this low pollution

Study the efficiency of the combined system of coagulation and flocculation/ozonation in treatment of fresh landfilI leachates in Tabriz city

Fresh leachate has a low pH and high amounts of BOD and COD which are mainly constituents with low weight molecular such as volatile fatty acids [acetic and propionic acids] .Management and treatment of leachate is an important subject in sanitary landfill operation and performance.The objective of this study is determining the efficiency of the integrated coagulation -flocculation and ozonation processes in fresh leachate treatment of Tabriz city. Quantitive parameters of pH, BOD[5], COD, alkalinity and TSS were studied based on standard methods.The study emphasizes of COD and TSS leachate removal.Alum, ferric chloride and PAC had been used as coagulants. Results indicated the superiority of Ferric chloride at the dosage of 1 g/1 in pH 10, which reduced 34% of COD and 54% of TSS.in the stage of ozonation the leachate sample coagulated by ferric chloride was treated by 3 g/h ozone gas at optimum pH and after 39 hours ozonation about 51% of COD and 18.2% of TSS were reduced. This study clearly indicates that there would be need to apply biological treatment [after coagulation - flocculation] and ozonation, various advanced oxidation processes and / or other treatment methods for further reduction of COD in leachate and meeting discharge standards

Photocatalytic degradation of linear alkyl benzene solfunate from aqueous solution by TIO[2] nanoparticles

The possibility of linear alkyl benzene solfunate [LAS] photocatalytic degradation through application of TIO[2] nanoparticles was investigated. 10[mg/L] of LAS has been affected by either UV or TIO[2] and simultaneous use of both of them in separated experiments. Moreover, the effect of initial concentrations of LAS and TIO[2], pH, present various anions and different UV power was studied to determine the optimal operating conditions for LAS degradation in water. The amount of mineralization of LAS was reported by measuring the primary and final COD of the solution that was irradiated under optimized conditions. Maximum degradation was obtained at acidic pH, 50 mg/L of TIO[2] and 30 minute irradiation time. It was also shown that 99.5% of LAS was degraded in optimal conditions. Kinetic analysis indicated that photo catalytic degradation rates of LAS can be approximated by pseudo-first order model. Measuring the initial and final COD of illuminated solution under optimized conditions, indicated that almost complete mineralization of LAS was occurred. Based on the results, UV/TIO[2] process may be effectively applied in LAS removal in low concentrations but this process is not economically efficient in high concentrations

[Photocatalytic degradation of phenol in aqueous solutions by Fe[III]-doped TiO2/UV process]

Phenol and phenolic compounds are widely used in industry and daily liFe, and are of high interest due to stability in the environment, dissolution ability in water and health problems. In this regard, phenol removal from water is of high importance. The purpose of this study was to investigate the efficiency of photodegradation process for removal of phenol from aqueous system by use of Fe-doped TiO[2] nanoparticles prepared by sol-gel method. Phenol concentrations of 5, 10, 50 and 100 mg/L were prepared and exposed to UV and Fe-doped TiO[2], separately and simultaneously. Also the effect of initial phenol concentration, Fe-doped TiO[2] loading and pH were studied. Various doses of photocatalist investigated for Fe- doped TiO[2] were 0.25, 0.5 and 1 g/L. pH was studied at three ranges, acidic [pH=3], neutral [pH=7] and alkaline [pH=11]. Maximum degradation was obtained at acidic pH, 0.5 g/L of Fe-doped TiO[2] for all of phenol concentrations. With increasing initial concentration of phenol, photocatalytic degradation decreased. In comparison with Fe-doped TiO[2]/UV process, efficiency of UV radiation alone was low in phenol degradation [% 64.5 at 100 mg/l of phenol concentration]. Also the amount of phenol adsorbed on the Fe-doped TiO[2] was negligible at dark conditions. Results of this study showed that Fe[III]- doped TiO[2] nanoparticles had an important effect on photocatalytic degradation of high initial phenol concentration when Fe[III]-doped TiO[2]/ UV process applied

[Investigating the efficiency of UV/H[2]O[2] process for removal of linear alkylbenzene sulfonate [LAS] in aqueous solutions]

Surfactants are one of the largest pollutants which exist in urban and industrial wastewaters. Large quantities of surfactants have entered to the environment since last decade due to increased use of synthetic detergent in industrial and home consumptions.In this study, the efficiency of UV/H[2]O[2] process in removal of linear alkylbenzane sulfonate [LAS] from aqueous solutions was investigated. In this study methylene blue active substane[MBAS]method and spectrometery were used to determine anion and residual surfactant respectively. In this study important variables were H[2]O[2] concentration, initial concentration of surfactant, pH and duration of UV radiation. The effect of UV/H[2]O[2] process on the degradation of LAS was analyzed statistically by using Multiple Linear Regression test. The resulted showed that after 20 minute, ultraviolet radiation solely removed 38.44 percent of Anionic detergent, Hydrogen peroxide showed no significant removal of detergent solution in the time course study. The efficiency of UV/H[2]O[2] process in 10, 20 and 30 minute were to 86.2, 90 and 96.5%, respectively. The results showed that the efficiency of ultraviolet radiation and hydrogen peroxide process in anionic detergent was not significant thoogh it was considerable in combination process [UV/H[2]O[2]]

Survey on degradation rates of trichloroethylene in aqueous solutions by ultrasound

Sonochemical degradation of different compounds such as chlorinated aliphatic hydrocarbons is one of the recent advanced oxidation processes and it may be effective for removing low concentration organic pollutants from aqueous streams. Trichloroethylene [TCE] is one of these compounds that is mainly used as a degreaser. Important studies about TCE sonolysis have been focused at millimolar levels and natural pH, but in this study the ultrasonic degradation of TCE at different micromolar initial concentrations [30, 300 and 3000 micro g/L] and 4 different initial pH with a 35 kHz frequency was investigated. Furthermore, the degradation of TCE by ultrasound with different concentrations of hydrogen peroxide at pH= 7 was also performed. Gas chromatography with FID detector was used for analyses of TCE. Results showed that the degradation of TCE increased with decrease in the initial concentration of TCE from 3000 to 30 micro g/L at all initial pH. Initial pH of solution and different concentrations of H[2]O[2] did not affect significantly the TCE destruction

[Removal of phosphate from aqueous solutions by Iron Nano Particle Resin Lewatit [FO36]]

Entrance of phosphorous into the lakes leads to algae growth and eutrophication the aim of this study was to assess the efficiency of iron nano particles as a new suitable and applicable method for removal of phosphorous. In this study Lewatit FO36 resin was covered with Fe [III] nano-particles, and it was used as a new way to eliminate phosphate. Column experiments were carried out in 11 stages in fixed bed columns with constant flow rate of 9 ml/min and the empty bed contact time [EBCT] of 2.1 min. phosphate solutions with concentrations of 1 to 16 mg produced at neutral PH were used in 6 steps of experiment NaOH and NaCl solutions were used for regeneration of resin. Then the effect of competing anions, chloride, sulfate, bicarbonate and their compounds on the efficiency of the resin was assessed. Finally the efficiency of the resin for removal of phosphate from water treatment plant sewage in Ghods suburb was studied. Data were analyzed by SPSS 13 soft ware. The capacities of adsorption of phosphate, with concentrations of 1 to 16 mg, by each gram of resin were 1.31, 1.35, 1.53, 1.64, 1.7 and 1.75. The capacity of regenerated resin for removal of phosphate with a concentration of 6 mg/l was 1.6 mg for each gram of resin which showed a 8.5% decrease. The result of this study showed increased adsorptive capacity of resin with increased concentration of phosphate. Chloride, sulfate, bicarbonate ions and the combined anions had no effect on phosphate removal