[Evaluation of the natural gamma radiation level in residential zones and determination of annual effective exposure dose in the residents of Hamadan province, Iran, 2012]

Human is always exposed to natural background ionizing radiation which may have harmful effects; therefore, measurement of the natural background radiation is important. In this study, was measured the dose of effective natural background gamma radiation in indoor residential zones of Hamadan Province. In this cross-sectional study, we selected four stations along the main geographic directions and one in the center of city for measurement of the indoor dose rate in each of the cities in Hamadan Province. Based on the household numbers, some houses were selected randomly in every station and natural background indoor dose was measured by using RDS-110 survey meter. Then, using the results of our previous study about measuring the level of outdoor natural gamma radiation in this province, we determined the level of annual effective exposure dose from natural gamma radiation in Hamadan residents. In Hamadan province cities, maximum and minimum indoor natural background radiation [gamma ray] belonged to Razan City [1.41 +/- 0.079 mSv] and Asadabad City [0.955 +/- 0.044 mSv], respectively. Mean annual equivalent indoor dose in Hamadan Province was 1.20 +/- 0.070 mSv. Also the maximum indoor natural background radiation dose [gamma ray] in the buildings with the age of more and less than 25 years were 1.42 +/- 0.219 mSv and 1.44 +/- 0.149 mSv, respectively. According to the results of this study and our previous study about outdoor gamma natural background radiation, the annual effective dose in Hamadan Province residents was 0.83 mSv. According to the results of this study, it seems that annual effective equivalent dose due to indoor gamma radiation in Hamadan Province exceeded the mean external exposure amount reported by UNSCEAR [0.5 mSv]. Also the annual effective dose due to gamma background radiation in Hamadan Province residents is 0.83 mSv, which is higher than the global average [0.48 mSv] reported by UNSCEAR - 2000. Therefore epidemiological studies to assess the prevalence of chronic diseases associated with natural radiation exposure among Hamadan Province residents are recommended

Comparison the efficacy of fenton and "nZVI + H[2]O[2]" processes in municipal solid waste landfill leachate treatment [case study: Hamadan landfill leachate]

Leachate contains large amounts of pollutants, including organic and inorganic materials as well as the types of pathogens. This study was performed with the aim of determining the efficiency of Fenton and" nZVI[nanoparticles of zero valent iron] + H[2]O[2]" processes for reducing chemical oxygen demand [COD], 5-day biological oxygen demand [BOD[5]], total solids [TS]and color of Hamadan city landfill leachate. Experiments were performed in batch reactor and main affected factors; pH, reaction time, concentration of iron and H[2]O[2] were investigated. Also the efficiency of processes was analyzed using One-Way ANOVA statistical test and SPSS-13 software. The highest removal efficiencies obtained with "nZVI + H[2]O[2]" process [48.67%, 52%, 10.44% and 53% for COD, BOD[5], TS and color, respectively in 2.5 g/L iron nanoparticles concentration, 29137 mg/L H[2]O[2], pH = 2.5 and 60 min reaction time]. Based on the results, the nZVI + H[2]O[2] process can be applied as Hamadan city landfill leachate treatment to correct the BOD[5]/COD ratio to increase the biodegrability of this type of wastewater

Evaluation of aluminum-coated pumice as a potential arsenic [V] adsorbent form water resources

In this study, the removal of As [V] from water resources by using aluminum-coated pumice as a new adsorbent was assessed. The features of the adsorbent coating layer were observed by X-ray diffraction [XRD] and Scanning Electron Microscopy [SEM]. The effects of various parameters such as adsorbent doses, pH, contact time, arsenate initial concentration and interfering ions in arsenic adsorption and achieving high removal efficiency were studied. The results showed that the adsorption of As [V] was extremely influenced by the phosphate interfering ions. It was also defined that more than 98% of As [V] was removed by 10 g/L of the adsorbent with initial As [V] concentration of 250 micro g/L at pH =7 and in 160 minutes. The adsorption equilibrium were analyzed by Langmuir and Freundlich isotherm models. Such equilibriums showed that the adsorption data was well fitted with Freundlich isotherm model [R[2] >0.99]. The data achieved from the kinetic studies were processed by kinetic models of pseudo-first-order. The results indicated that the pseudo-second-order model could describe the adsorption of As [V] by pumice coated with alum [R [2] >0.92]. According to achieved results, it was defined that aluminum-coated pumice not only was an inexpensive absorbent, but also a quite effective factor in removal of As [V] from water resources

Comparison between the efficiency of advanced oxidation process and coagulation for removal organophosphorus and carbamat pesticides

Water pollution by pesticides has adverse effects on the environment and human health, as well .In recent years, advanced oxidation processes, have been gone through to a very high degree for pesticides removal. Poly-Aluminum chloride [PAC] used for water treatment, can be effective on pesticides removal. The aim of this research was to study the use of UV/O3 and PAC in the removal of pesticides from drinking water. In this descriptive- analytical survey, specific concentrations of pesticides [1,5,10,15,20 ppm];namely Diazinon, Chlorpyrifos, Carbaril were prepared through addition to deionized water. Dichloromethane was used for samples extraction, samples extracted with Liquid-Liquid and Solid-phase extraction, finally entered bath reactor at pH [6,7,9] .The samples then exposed to UV/O3at contact time of [0.5,1,1.5 and 2 hours]. In the PAC pilot, the effects of various concentrations of pesticides, and PAC - ranging [12/24 and 36 ppm] were investigated for the efficacy of pesticides removal. All samples analyzed by GC/MS/MS and HPLC. It was found that in U V/O3 reactor, with the rise of pH, decrease in pesticides concentration, and rise of contact time, the efficiency of removal increased too. In the PAC pilot, increase in PAC concentration and decrease in pesticides concentration, both increased the efficiency. Besides, both of the methods showed high efficiencies in the removal of both pesticides,i-e. halogenated Organophosphorus [Chlorpyrifos], non- halogenated Organophosphorus [Diazinon] at the degree of over [%80]; In case of carbamate pesticides [e.g. Carbaril] efficiency was over [>%90]. One-Way Anova and Two -Way Anova were used to analyze the obtained data. According these results these two methods are suggested for the removal of pesticides from aqueous solutions

comparative study on arsenic [III] removal from aqueous solution using nano and micro sized zerovalent iron

The present study was conducted for Arsenic [III] removal, one of the most poisonous groundwater pollutants, by synthetic nano and micro size zerovalent iron [n-mZVI]. Batch experiments were performed to investigate the influence of As [III], nZVI and mZVI concentration, pH of solution and reaction time on the efficiency of As [III] removal by Fe[o] particles. Nano ZVI was synthesized by reduction of ferric chloride by sodium borohydrid. Scanning Electron microscope and X-Ray diffraction were used to determine particle size and characterization of produced nanoparticles. Results showed up to 99.9% removal efficiency for arsenic [III] that was obtained by nZVI dosage of 1 g/L at equal time of 10 min and pH=7. The maximum removal efficiency by mZVI obtained in initial arsenic concentration of 1 mg/L and mZVI dosage of 10 g/L after 120 min. and pH=7. It could be concluded that the removal efficiency was enhanced with increasing n-mZVI dosage and reaction time, but decreased with increasing of arsenic concentration and pH for both nano and micro sized ZVI. Nano ZVI presented an outstanding ability to remove As [III] due to not only a high surface area and low particle size but also to high inherent activity

[Photocatalytic removal of hexavalent chromium and divalent nickel from aqueous solution by UV irradiation in the presence of titanium dioxide nanoparticles]

Industrial wastewater included the heavy metal is one of the important sources of environmental pollution. Hexavalent chromium and divalent nickel are founded in plating wastewater which is harmful for human health and environment. Therefore, the purpose of this research is investigation of photocatalytic removal of hexavalent chromium and divalent nickel from aqueous solution using UV/TiO[2] process in a batch system. At first, reactor was designed. Then, optimumdosage of TiO[2] was obtained equal to 1 g/L, with variation TiO[2] dosage at constant pH and initial concentrations of hexavalent chromium and divalent nickel. The effect of pH, contact time and initial concentration of hexavalent chromium was studied at the constant amount of TiO[2] [1gr/L]. The result showed that photocatalytic removal efficiency increased with increasing reaction time and TiO[2] dosage. In addition, it was found that removal efficiency of hexavalent chromium was decreased by increasing initial chromium concentration and pH. But, photocatalytic removal efficiency of nickel ion was increased and decreased by increasing of pH and initial nickel concentration, respectively. The results showed that UV/TiO[2] was an effective method in removal of hexavalent chromium and divalent nickel from aqueous solutions

[Performance of simple nano zeolite Y and modified nano zeolite Y in phosphor removal from aqueous solutions]

Phosphate discharges from domestic and industrial waste water to water bodies. High concentrations of phosphate in water stimulate the eutrophication phenomenon that causes taste and odor in water, losing dissolved oxygen and aquatic life in rivers or surface waters. Aim of this study is survey of phosphate adsorption on simple nano zeolite Y and nano zeolite Y that was modified with a cationic surfactant [HDTMA-Br]. In This study we used simple nano zeolite Y and nano zeolite Y in form of Surfactant Modified Zeolites [SMZs] using batch tests to adsorption of Phosphate from Aqueous Solutions. The adsorbants were contacted with different initial phosphor concentrations [5, 10 and 15 mg/l], pH [4, 7, 12], contact time [30, 60, 90, 120, 150 and 180 minutes] and weight of adsorbant [0.2, 0.4, 0.6, 0.8 and 1g]. the extracted solution was determined for Phosphate concentration by the ammonium molybdate and tin chloride method with spectrophotometric detection at 680 nm. Results of this study show that, with increase in contact time, decrease in pH, increase in zeolites concentration and decrease in initial phosphate concentration, the removal efficiency increased. And the Both isotherm of Langmuir and Freundlich models [r[2]>0.997 and r[2]>0.996 respectively] were agreement with adsorption equilibrium of phosphate. Reduced Chi-Sqr For Langmuir and Freundlich models were [0.00079] and [0.0011] respectively. Pseudo first-order kinetic models fits well with experimental data [r[2]>0.963]. From this survey, it is concluded that performance of modified nano zeolite Y for adsorption of phosphate in same conditions is better than non-modified zeolite Y. In general the modified nano zeolite Y presented a good profile for removal of phosphate. Therefore SMZs is a suitable candidate for removal of Phosphate molecules from contaminated solutions in contaminated waters

[Comparison of diffrent coagulants efficiency for treatment of Hamedan landfills leachate site]

In Iran, indicated that the municipal landfill leachate has been one of the major problem for environment. In the operations, leachate treatment is a very difficult and expensive process. Although, young leachate can be treated easily by biological treatment, COD removal efficiency are usually low due to high ammonium ion content and the presence of toxic compounds such as metal ions. Treatment of leachate is necessary.The aim of this study is reduction of Chemical Oxygen Demond [COD] and Total Suspended Solids [TSS] from hamedan city sanitary landfill leachate by three coagulants: alum, PAC and ferrous sulfate. This experimental study was conducted to investigate the effect of treatment of landfill leachate by a coagulation-flocculation process. The effects of different amounts of coagulant and different pH values on the coagulation processes were compared. result of this survey show that the high efficiency for COD removal by PAC in pH=12 and 2500[mg/l] concentration of PAC was 62.66%, by alum in pH=12 and 1000 [mg/l] concentration of alum was 60%, by ferrous sulfate in pH=2 and 1000 [mg/l] concentration of ferrous sulfate was 70.62%. Also result shown the high efficiency for TSS removal by PAC in pH=12 and 2500[mg/l] concentration of PAC was 58.37%, with alum in pH=2 and 1500 [mg/l] concentration of alum was39.14%, by ferrous sulfate in pH=7 and 2500[mg/l] concentration of ferrous sulfate was 35.58%. The best coagulant for COD removal is ferrous sulfate.The physico-chemical process may be used as a useful pretreatment step, especially for fresh leachates, prior to post-treatment [polishing] step for partially stabilized leachates

[Determination of organophosphorous and carbamat pesticides residue in drinking water resources of Hamadan in 2007]

Water contamination by pesticides is considered as an environmental problem today. In terms of agricultural development and diversity of plant pests, the use of pesticides has been increasing. Hamedan province has a suitable agricultural condition, it has enjoyed significant development in this respect. Among all the cities of Hamedan province, Hamedan city has the highest rank in tiller crops. Therefore, yearly use of pesticides is increasing in this area which could be a serious threat to water resources of the city. The aim of this survey was determinaton of Organophosphorous and Carbamat pesticides residue in drinking water resources of Hamadan in 2007. In this survey, 126 water samples were collected from 7 drinking water resources of Hamedan during 12 consecutive months in 2007. for determination of these pesticides, two methods [solid-phase extraction and Liquid-Liquid extraction] were adopted .and samples were analyzed by means of HPLC and GC/MS applying standard methods. Final results showed that the most concentration of Chlorpyrifos and Carbaryl pesticides were found to be about 3.85 ppb [part per billion] and 1.8 ppb in spring and June respectively; the maximum concentration of Diazinon was about 36.5ppb in October [autumn].The minimum concentration of the three pesticides was detected in winter. According to the statistical test Two-Way ANOWA there were significant differences among pesticides concentrations in the water samples in different seasons [p<0.05]. However, there wasn't a significant difference in pesticides concentrations in surface and ground water samples[p>0.05]. Different studies have shown that pesticides residue concentration in water samples have a relationship with the amount of pesticides used in an area, physical and chemical refractory properties of pesticides; and environmental conditions. Thus, using resistant pollutants such as pesticides will be a serious threat to health of water consumers if they are not properly controlled

Hamadan landfill leachate treatment by coagulation-flocculation process

In 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

Evaluation of chemical quality in 17 brands of Iranian bottled drinking waters

The purpose of study was to evaluate and compare chemical quality of Iranian bottled drinking water reported on manufacturer's labeling and standards. This study was a cross-sectional descriptive study and done during July to December 2008. The bottled mineral water collected from shops randomly were analyzed using all parameters address on manufacturer's labeling and the results were compared with the manufacturers' labeling data, WHO Guideline Values, USEPA Maximum Contaminant Levels and the maximum contaminant levels of drinking water imposed by the Iranian legislation. Statistical analysis on data was done with the Kolmogorov-Smirnov test for normal distribution, the paired t-test to compare the data with manufacturer's labeling and the one-sample t-test to compare with standard and MCL values at P<0.05 of confidence level. The results showed a statistically significant difference with manufacturer's labeling values, however there was no significant difference between the values of magnesium and pH and manufacturers' labeling values [P>0.05]. In addition, ph and calcium values were significantly higher that their proposed values indicated by Iranian National Legislation and international MCLs [P<0.05]. Our results are extremely important for the health supervisory agencies such as Ministry of Health and Institute of Standards and Industrial Research of Iran to have more effective controls on bottled water industries, and to improve periodical the proposed standard values

[Hexavalent chromium removal from aqueous solution by produced iron nanoparticles]

Groundwater treatment by nano particles has received increasing interest in recent years. Chromium is a commonly identified contaminant in soils and groundwater. Zero-valent iron, as a natural reduction agent can be used in controlling of contaminated sites. The aim of this research is investigation of hexavalent chromium removal from aqueous solutions by using of iron nano particles the effective parameters. In this research the synthesized of the iron nano particles has performed by addition of NaBH4 to FeCl3 6H2O solution and Cr[VI] reduction efficiency in Batch system was studied. Also the impact of the important field parameters including pH, initial chromium concentration, nano zero valent iron concentration and retention time were investigated. The results of this research showed that synthesized particles were in nano scale. In pH=3, chromium inlet concentration of 10 mg L-1, nano zero valent iron concentration 0.5 g L-1 and 2 minute retention time, 100% of Cr[VI] was removed. The concentration of nano zero valent iron had significant effect on the reduction of Cr[VI]. The reaction occurred in a wide range of pH value and the reaction efficiency increased significantly with decreasing initial pH. The significant removal efficiency, high rate of process and short reaction time were showed that iron nano particles have significant potential in removal ofCr[VI] from contaminated water

Investigation of clinoptilolite natural zeolite regeneration by air stripping followed by ion exchange for removal of ammonium from aqueous solutions

The purpose of this study was to regenerate clinoptilolite natural zeolite by air stripping followed by removal of ammonium from aqueous solutions. The research was carried out in continuous system. The characteristics of graded clinoptilolite from Semnan [one of the central provinces in Iran] mines were determined and then regeneration tests were done by contacting of 1 N NaC1 solution with given weights of ammonium saturated zeolite. Then the brine of column was transferred to the air stripping column for regeneration. The pH of brine solution before entrance to a stripping column was increased to 11. Air stripped ammonia from the brine was converted to the ammonium ion by using acid scrubber. The outlet effluent from stripping column was collected for reuse. The results showed that the cation exchange capacities were 17.31 to 18.38mg NH[4+]/g of zeolite weight. Regeneration efficiency of zeolite by NaC1 solution and air stripping was in the range of 92%-97% under various operational conditions. However, the efficiency of acid absorption of released ammonia in stripping process was 55% with a major rejection of the surplus ammonia to the atmosphere. It could be concluded that the method studied may be considered as an advanced and supplementary process for treating effluents of aqueous solution and fishponds in existing treatment plants

[Quantity and quality analysis of Malayer municipal solid wastes from Autumn 2006 until Summer 2007]

Municipal Solid Waste [MSW] management and planning without adequate and reliable data about its physical components and generation rate are not obtainable. Because of MSW collection and landfilling expenses, in last decades, reuse and recycle of its components as an environmental object have been considered. In this research, in order to determine the possibility of source recycling application in Malayer and physical composition of MSW, samples were taken by Truck-Load method and cluster random sampling from autumn 2006 until summer 2007 and analyzed for physical components percents. The obtained data were analyzed by One-Way ANOVA and Tuky statistical test. Also, public partnership was investigated. Public opinion deliberation was accomplished by dividing the city into several clusters. Questionnaires were filled by oral interview conversation. The results showed that average daily generation rate was 138 Tons and 0.88 Kg per person per day. The average percent of recyclable materials was about 11% of total daily generated wastes. Also 99% of residents had positive response to source recycling plans. In general, by planning of enforceable reuse and recycling programmes, could avoid of 15 Tons of recyclable materials burial and save 19 millions Rials each day

Photocatalytic disinfection of Coliform bacteria using UV/TiO[2]

There are great interests in photocatalytic oxidation of contaminants using titanium dioxide in recent years. The main objective of this research was to study photocatalytic disinfection of Coliform bacteria as water microbial pollution index using TiO[2] and a low pressure UV lamp in a batch reactor. The polluted water was prepared by adding a colony of Coliform in raw water and in separate stages was contacted with UV, TiO[2] and combination of them and various parameters such as contact time, pH and amount of TiO[2] were studied in terms of their effect on reaction progress. The results showed that in simultaneous presence of both UV ray and TiO[2], there was the most effective disinfection of Coliform. This study showed that 100% of Coliform was killed by irradiation for 60-75 min. in the presence of 0.8 gr 1[-1] TiO[2] in pH=7.0. Based on the results, UV/TiO[2] process may be effectively applied for disinfection of polluted water and can be suggested as a effective purifying method for water disinfection

[Servey impact of activated alumina in fluoride concentration peresent in water and appointment adsorption isotherm and kinetics]

Determination of Fluoride in drinking water has received increasing interest, duo to its beneifical and detrimental effects on health. The aim of this research is investigation of Effect of activated alumina in fluoride concentration reduction in drinking water. Expriment in batch system and with change effective parameters such as pH[5, 7,9], equilibration time [30, 60, 90, 120 minute], initial fluoride concentration[1.4, 2, 2.4 mg/1] and activated Alumina dosage [0.1,0.2,0.3 gr/1] was investigated. Also found data of this research were fited with Langmuir and Freundlich models, kinetic data with pseudo- first order, pseudo- second order and modifited pseudo-first order models. The results showed that with increasing of pH of solution, removal efficiency was decreased and optimum pH was found to be in the range of 5 to 7. Also removal efficiency of fluoride was increased with increasing of adsorbent dosage and decreasing of initial concentration of fluoride. Adsorption isotherm data show that the fluoride sorption followed the Langmuir model [r[2]=0.98]. Kinetics of sorption of fluoride onto Activated alumina was well described by pseudo- second order model. The concentration of Activated Alumina had significant effect on the reduction of fluoride ions concentration in water. The higher fluoride removals were observed for batch experiments at pH=5 because no free fluoride ion is present in the solutions, and it could be casued by electrostatic interactions between the surface of alumina and the dominant fluoride species in solution The kinetic model can adequately describe the removal behaviors of fluoride ion by alumina adsorption in the batch system

[Removal of excess fluoride from water plants by poly aluminum chloride as a new coagulant]

The fluoride ions are commonly found in water resources. These ions should be in optimum levels for prevention of dental caries. However, the excess value can cause such health problems as fluorosis. The aim of the present study was to investigate the removal of excess fluoride ions by using poly aluminum chloride as a new coagulant that is used in water treatment plants. All experiments were conducted in batch system. Several combinations of parameters such as initial fluoride concentration [1.4, 2 and 2.4 mg/L], pH of solution [3, 7, 9], poly aluminum concentration [10, 20, 30, 40 mg/L], and exposure time [30, 60, 90 minute] were investigated. Various concentrations of poly aluminum chloride solution at different pH levels were added into 200 ml of fluoride solution, and samples were taken in predetermined time intervals and the final concentration of fluoride was determined by spectrophotometer at 570 nm. The results showed that, the highest removal was obtained at pH=7. In addition, it was observed that fluoride removal efficiency was higher in pH=5 than in pH=9. Also the results showed that, removal efficacy can be increased by increasing the poly aluminum chloride and the exposure-time. This study denoted that removal of high levels of fluoride ions can effectively be done by using poly aluminum chloride as a new coagulant. Its use is possible in water treatment facilities without any need for modification in water treatment plans

Investigation of photocatalytic degradation of phenol by UV/TiO[2] process in aquatic solutions

The main objective of this research was to study photocatalytic oxidation of phenol in aquatic solutions by using of UV, TiO2 and the combination of them. Phenol compounds are widely used in industries and other daily life. Highly toxicity and carcinogenicity of these compounds can causal considerable adverse effects on the aquatic ecosystems and human health. The study was an experimental research and carried out by phenol 100 mg L-1 solution and contact time, pH and amount of TiO2 were considered in photocatalytic system as the basic variables affecting removal efficiencies. Phenol concentration in inlet and outlet samples was detected by spectrophotometery at 500nm. Combination of UV and TiO2 can cause higher efficiencies of phenol removal. The removal efficiencies of UV, TiO2 and UV/TiO2 photocatalytic oxidation system with various operation conditions had a range of 1.8%-19.64%, 2.38%-17.8% and 34.65%-82.91%, respectively. It was found that increasing of TiO2 concentration and contact time and pH, increasing the amount of phenol that oxidized in combined system and maximum removal coefficients obtained in pH = 11, 9 h contact time and 0.2 gr of TiO2. Combinated UV/TiO2 process may be applied as an effective process for the removal of phenol from aquatic solutions such as industrial wastewaters and polluted water resources

Removal of chloroform [CHCL3] from Tehran drinking water by GAC and air stripping columns

The harmful substances, defined as trihalomethanes [THMs], were found to be formed during the disinfection of drinking water when chlorine was used as the disinfectant. In this research, the effectiveness of granular activated carbon [GAC] and air stripping [AS] packed column for the removal of chloroform [CHCL3] [as THMs basic indicator compound in many resources] in range of 50 to 300 micro g/L, from drinking water was studied. Pilots of GAC and air stripping columns were designed and set up. The study was carried out for the two cases of deionized and chlorinated Tehran tap water. Also the effects of flow rate, chloroform and TDS concentrations were considered in both treatment systems. Gas chromatography [GC] with electron capture detector [ECD] was used for determination of chloroform concentration in inlet and outlet samples. The obtained data were analyzed by SPSS and non-parametric KruskaI-Wallis method. Results showed a positive correlation between the flow rate and chloroform concentration, and removal efficiencies. The average of variations of removal efficiencies for AS and GAC columns with deionized water samples were, 89.9%, 71.2% and for chlorinated Tehran tap water were 91.2% and 76.4%, respectively. The removal of feed residual chlorine in these columns with 0.5, 0.8 ppm was 100%, respectively and re-chlorination for finishing water was recommended. Results showed AS to be considered more effective in chloroform removal for conventional water treatment plants as a finishing process

Comparison of Nanofiltration and GAC Adsorption Processes for Chloroform Removal from Drinking Water

In this research, the Chloroform [CHCl3] removal effectiveness of two water treatment systems including membrane technology and granular activated carbon [GAC] adsorption were studied. Two bench-scales were designed and set up: 1] Nanofiltration [NF] spiral-wound modules and 2] GAC adsorption column. Chloroform was considered as trihalomethanes [THMs] basic indicator compound. The inlet and outlet CHCl3 concentrations were detected by gas chromatography [GC] with electron capture detector [ECD]. The study was carried out for the two cases of spiked deionized water with CHCl3 and chlorinated Tehran tap water. Flow rate, CHCl3 and total dissolved solids [TDS] concentrations were considered in both treatment systems and the transmembrane pressures for membrane pilot, as the basic variables affecting removal efficiencies. Results showed that CHCl3 rejection coefficients for NF 300 Da, NF 600 Da and GAC Column, with various operation conditions had a range of 55.2% to 87.8%, 78% to 85% and 41.4% to 74.1%, respectively. It was found that removal efficiencies for NF 600 Da were lower than those of NF 300 Da and GAC column. The obtained data were analyzed by SPSS and non-parametric Kruskal-Wallis method. Results showed a positive correlation between the flow rate, CHCl3 concentration and chloroform rejection coefficients and the TDS concentration had no significant effect on chloroform removal efficiencies