فصلنامه کومش
سال هجدهم شماره 3 (پیاپی 63، پاییز 1395)

Photo catalytic technology has been studied extensively since 1970. A lot of researches have been done to understand the basic processes and structure and photo catalyst efficiency increasing, particularly for the prevention and control of water, air and soil pollution. This method is attractive because of the impossibility of removing many contaminants to conventional and common methods and using atmospheric oxygen as the oxidizer, the possibility of complete mineralization of organic matters to the H2O and CO2 and this process could be used under the environmental conditions. During the past year a lot of attention has been paid to the reaction of photo semiconductors, metal oxides such as Titanium dioxide, Zinc oxide, zirconium dioxide, tungsten trioxide and cadmium sulfide (photo catalytic oxidation). In this case, nanotechnology will find wide application in the future with the creation of a new approach in the photo catalyst industry. In nano -scale particles, not only area increases considerable, but also other effects on optical and electromagnetic properties will be increased. Studies showed that photo catalytic reaction rate increases with the particle size reducing and increasing in the oxidation – reduction potential, significantly. Even in some conditions, the energy emitted from the light source can be used in place of ultraviolet radiation and it could be the effective energy source for photo catalyst. Nano photo catalysts with the hydrophilic and strength nanostructured catalytic properties due to their high surface area to volume are one of the key technologies for environmental pollutant control. The nano photo catalyst technology could have used for applications in water filtration systems, waste and air for removal of resistant and dangerous contaminants properly.

Water resources in karst areas are very important water supply from the aspects of quantity and quality in the world. Due to the wide scattering these resources in the country and in the province, this study was performed to determine the quality of karst water resources in Golestan province.
In this study the chemical and microbial quality of water of the most important Karst resources of Golestan Province (Iran) due to potability and irrigational consumption was performed in the Gorgan, Kalaleh, Azadshahr and Galikash cities, as a sectional manner within the two seasons of 2014-2015. For this purpose, 10 parameters of 12 water Karst resources were determined and qualitative classification of water was performed using Aq.qa software.
Results showed that the qualities of the total water resources are in the ranges of hard and very hard waters. The survey of water quality class showed that most of water samples were excellent in two seasons. Due to the Wilcox quality index, some of the resources as appropriate for agricultural use and some are not. All of samples are in middle class for drinking and no bacterial contaminants observed in water samples.
Generally, considering the importance of Karst resources in terms of proper quality and quantity compared with water dams in the country and the Golestan Province, comprehensive survey and study in quantitative and qualitative aspects of these resources should be done as a solution for supplying of agricultural irrigations and drinking waters.

One of the important factor in the control of water quality is, the corrosion potential and sedimentation, because for health and economic aspects. The purpose of this study was to evaluate the corrosion and scaling of drinking water resources of Noor, a city in Iran.
This cross-sectional study was conducted in water resources of Noor city (Mazandarnae Province of Iran) and sampling was done twice in the summer and automn seasons from 19 drinking water wells. Calcium hardness, PH, total alkalinity, TDS and temperature were measured based on the standard methods. The Langelier, Rayzner, Puckhorius and Aggressive indexes were calculated.
The mean of temperature, pH, total dissolved solids, calcium hardness and total alkalinity in the water samples were 21°c, 7.25, 434.3 mg/l, 105 and 324 mg/l as CaCO3, respectively. The average of LSI, RSI, Puchorious and aggressive indices in summer were 0.28, 7.82, 6.86 and 11.73; in autumn were 0.25, 7.75, 6.7­ and 11.78, respectively.
Comparison of four indices and obtained results showed that drinking water resources in Noor city was coorosive. Therefore, it is suggested that laboratorial examinations such as pH, total alkalinity, dissolved oxygen and chloride and sulfate ions should be assessed

Pollution from cadmium is enters the environment through different industrial wastewater. The main goal of this study was to investigate the removal efficiency of cadmium by compound of titanium dioxide and rice husk silica from aqueous solutions.
The removal of Cadmium experiments in this experimental study carried out in batch reactors. Rice silica was prepared in a furnace heated to 800 °C for 4 hours after acid leaching. Deposited silica with TiO2 was prepared in a furnace heated 450 °C for 1 h, after the deposition by Deep Coating method. Scanning Electron Microscope (SEM) was applied the absorbent silica and deposited silica to compare of surface morphology before and after stabilizing the TiO2. The effects of initial concentrations of cadmium, dosage of adsorbent and retention time on the removal of cadmium were studie.
Based on the results of SEM the morphology of rice husk silica has been not changed after stabilization of Tio2. The results showed that removal efficiency decreased with increasing the concentration of cadmium and increased with increasing contact time and the dosage of deposition adsorbent. The maximum removal efficiency was obtained up to 89.65% at initial concentration of 1 mg/l of cadmium, 1.5 g/l dosage of deposited adsorbent and retention time of 60 min
The results of this study showed that nanophotocatalytic titanium dioxide and rice husk silica could be considered as an effective compound for the removal of cadmium from aqueous solutions

Diazinon is an organophosphate pesticides that widely used for agricultural pests and vectors. Diazinon resists to biodegradation so there is major concern about it. The aim of present work was to study the decompostionof diazinon by nano-photocatalytic ZnO-TiO2 in the presence of UVC radiation.
This work is a laboratory-experimental study. Characterization of nanoparticles was determined through TEM pattern. The number of samples was determined by Taguchi statistical method. The samples with definite concentration of diazinon and nanopartical in different operational conditions were exposed to UVC radiation, individually .Diazinon concentration was measured using HPLC. Data analysis was performed using the software Minitab 16.
The results showed that with increasing reaction time, the removal of diazinon increases but by increasingthe dose of nanoparticles and Diazinon concentration the removal rate decreases. The highest removal efficiency rate was 95%.
The combination of catalysts is a new method for the removal of diazinon. The results showed that the photocatalytic nano-ZnO-TiO2 has a positive effect on diazinon degradation

In recent years, pharmaceutical contaminantshas created much concern for environmental experts. Therefore, it is important to find effective methods to remove of them from the environment. One of appropriate methods, in order to remove these contaminants is using nanocatalysts process.
In this experimental study, zero-valent iron nanoparticles synthesized in laboratory conditions, and its characteristics were determined by SEM and XRD analyses. In this study, it was investigated effects of factors such as pH, nanoparticles concentration and hydrogen peroxide concentration in removal of sulfathiazole antibiotics in aqueous solutions. All sampling and testing was performed according to standard methods for water and wastewater.
The result of this study showed that pH, as a very effective agent, has a major impact on the efficiency of the nanocatalysts process and removal efficiency is higher at lower pH. Maximum efficiency was 99.87 percent that obtained time 60 min, pH =3, Nzvi = 1g / L and H2O2 = mmol 1.
Synthesized zero valent iron nanoparticles in the presence of hydrogen peroxide has a good efficiency to degradation of sulfathiazole and it can be suggested for wastewater treatment of pharmaceutical industry.

Heavy metals are one of the pollutants which are found in minor amounts in natural water and high concentration in industry waste water. Heavy metals poisoning effects are increasing in marine organisms especially fishes due to disposal of industrial wastes to marine environment and their bio accumulation. The aim of this study is to determine of mercury, cadmium and lead levels in canned fish sold in Mazandaran province of Iran.
This descriptive-cross sectional study was done on 12 types of canned tuna distributed, 3 numbers of each type and overall 36 sample. The concentration of 3 type heavy metals assessed with standard method by Atomic Absorption and then expressed based on µg/g of wet weight. The results were compared with WHO and Iran National Standard Organization.
The results show that, minimum and maximum of mercury level in 36 samples of canned tuna fish was 0.01 and 0.5 µg/g, cadmium 0.001 and 0.05 and lead 0.001 and 0.3 respectively. According to replicates experiments, the mean concentration of mercury in 12 such samples of canned tuna fish was from 0.106 to 0.31, cadmium from 0.006 to 0.022 and lead from 0.03 to 0.15µg/g.
that there was a significant difference in samples(p This research determined that the rate of mercury, cadmium and lead in canned tuna fish distributed in Mazandaran province were less than 0.5, 0.05 and 0.3µg/g and below the WHO/FAO- recommended levels.

Groundwater is the main source of drinking water and the life of many human societies depend on it. Continuous monitoring and assessment of groundwater quality changes are necessary because improvement and decontamination of polluted groundwater is very difficult and costly. The aim of this study was to determine the groundwater quality trend changes in Lordegan city (Iran) during one decade (2002-2012).
The required data were collected from the results recorded in the years 2002-2012 and analyzed by descriptive and analytical statistics (correlation coefficients).
changes of all of them were ascending. In the first and end year of the study period, the number of fecal coliform positive samples were 9(6.25%) and 14(9.75%) and the mean±SD of fecal coliform's MPN in positive samples were 0.24±0.04 and 0.83±0.40 respectively. Also the mean±SD of nitrate (as nitrate, mg/l), total hardness (as calcium carbonate, mg/l) and electrical conductivity (as micromhos/cm) in the first and end year of the study period were 16.6±6.56 and 21.7±10.76, 254±47 and 298±34 and 507±92 and 529±98 respectively. On the basis of spearman's correlation coefficient, the ascending trend of some parameters concentration with time was significant at the level of 95% of confidence limits (α≤0.05).
The ascending trend of concentration of all the parameters shows gradual declining of drinking water resources quality. Continuing the ascending trend of the parameters concentration and declining the quality of water resources and incompatibility with Iranian drinking water standard can lead to significant health risks, therefore, tracking the trend changes, investigating the reasons and preventive measures are important.

Production of adsorbent using agricultural wastes has important economic and environmental advantages. The aim of this study was Production of silica absolutely using agricultural wastes and determination of efficiency of produced adsorbents in removal of cadmium from aqueous solutions.
In this experimental study, two different type of acidic pretreatment and then thermal treatment was used for silica production from rice husk. The efficiency of the produced adsorbents was studied in four pH states, four cadmium concentration values, five adsorbents dosages and six different contact times. Cadmium concentration was determined by atomic absorption spectrophotometry.
silica was produced in the two procedures and both produced silica had good morphological and physical characteristics. The maximum efficiency of cadmium removal at pH= 6, adsorbent dosage of 3 g/l, contact time of 120 min and initial cadmium concentration of 5 mg/l, for rice husk silica produced by strong inorganic acids and waste lemon juice were respectively %90.1, %60.8. The adsorption processes followed the Freundlich isotherm)generally R2 ≥0.99(.
According to the results of this study, good rice husk silica can be produced using absolutely agricultural wastes (rice husk and lemon juice) and produced silica can be used as an effective and cheap adsorbent for removal of cadmium from aqueous solutions

Phenolic compounds are industrial chemicals that they are interested in due to the many health and environmental concerns. The aim of this study was to examine bio-electrochemical system performance to remove phenol from synthetic wastewater using a carbon cloth (as a bio-cathode) and steel wool (as a bio - anode) electrodes with a fixed bed.
The present study was an experimental study in laboratory scale. It was carried out in batch mode using1literplexiglass reactor. After starting up the system, effective parameters on process efficiency, including the C/N ratio, initial phenol concentration, applied current and reaction time were evaluated. Also, electrical conductivity, pH and redox potential (EC /pH /ORP) were studied during the reaction.
The results showed that with increasing the applied current from 2 mA to 6 mA (0.9 to 1.2 V), the bioelectrochemical degradation efficiency was promoted from 65% to 96.26%. The phenol removal was obtained 100% in C/N=5. The energy and power consumption were calculated 0.01- 0.14KWh/m3 and 0.02-0.23, respectively.
The experiments indicated the efficient removal of phenol in wastewater by electrochemical bioreactor using carbon cloth (as bio-cathode) and steel wool (as bio-anode) electrodes.This efficiency was due to the high bioelectrodes conductivity, more surface area for biofilm formation, operating current density and power consumption reduction. The performance of this reactor can also be considered to eliminate other biodegradable organic compounds

Because of the disadvantages of antibiotics in the ecosystem, it must remove before discharging wastewater containing them into the environment by an effective process. The aim of this study was cephalexin removal by local green montmorillonite loaded with TiO2 nanoparticles (TiO2/GLM) in the presence of potassium permanganate.
This experimental study was performed in batch. In this study, green montmorillonite found in the area of Ardabil sarcham used as base absorbent and to improve the efficiency of cephalexin removal stabilized TiO2 nanoparticles on it using potassium permanganate. Then, the most important variables affecting the process have been investigated. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) tests used to investigate absorbent surface morphology and functional groups on the adsorbent respectively. The samples were analyzed by a spectrophotometer and data analysis was performed using Excel software.
SEM images showed that the absorbent surface has a high roughness and FTIR test showed change the functional groups because loading of TiO2 nanoparticles.the optimal condition was pH = 5, detention time= 60 min and adsorbent dose = 4 g/l for initial Cephalexin concentration of 25 mg/l. Also the results showed by decreasing temperature, removal efficiency was increased.
Due to the high efficiency of TiO2/GLM in the absorption of cephalexin as well as its morphology did not change after adsorption process, we can say that this adsorbent can be used as a cheap and efficient absorbent for the removal of cephalexin used

The aim of the study was to investigate the effect of industrial development on the health risk level caused by drinking water's heavy metals with HRAEPA index in Semnan province (Iran).
In this descriptive-analytical study, sampling from 17 wells was perfumed at first. Then the samples immediately transported into laboratory and the heavy metals concentrations were measured with Standard methods 2008. Meantime, HRAEPA index was calculated with health risk assessment method.
Results showed that the levels of all heavy metals are at national, WHO and EU standard ranges. HRAEPA indexes was 4.48Í10-4, 4.36Í10-4 and 4.46Í10-4 for 2001-2011, 2012-2015 and 2015 period, respectively. Also, the highest and lowest HRAEPA index was for 2001-2011 and 2015, respectively.
The results showed that industrial development didn’t increase the level of health risk related to heavy metals. However, due to a significant progress of industrialization at Semnan province, water resources quality must be protected by law enforcement and tight supervision on industrial and mining - excavation activities

Besides aesthetic aspects, the discharge of textile wastewater into the environment create serious environmental problems as well. The objective of this research was to investigate the factors affecting the efficiency of the electrocoagulation process coupled with UV/H2O2 and determine the optimum conditions for dyes and COD removal from textile wastewater containing the orange reactive dye 122.
This experimental research was done at Environmental Health Engineering Research Center, Kerman University of Medical Sciences in 2014. In this research, the efficiency of Color removal and COD from synthetic solution under various conditions such as different pH (3, 6, 9), time (40, 30, 20, 10 minutes), flow (80, 20.60 amps per square meter) and initial concentration of H2O2 (80, 40, 20, 10 Mm/L) were measured. In addition, optimization experiments in real sewage have also been investigated.
the obtained results showed that the maximum efficiency of dyes and COD removal from synthetic solution in optimal condition of pH=6, flow rate=60 A/m2, initial concentration of H2O2 20 Mm/L, and 20 minutes’ reaction time was obtained 98% and 85.5% respectively. While, the maximum efficiency of dyes and COD removal from real wastewater samples was found 92% and 65.5% respectively.
Due to the use of fewer chemicals, non-residual products, low sludge production, and High efficiency of removal can be concluded that electrocoagulation process coupled with UV/ H2O2 is an effective method to remove the orange reactive dye 122 from wastewater of textile industries.