یوسف دادبان شهامت

Contamination of soils and aquatic environments with heavy metals is a serious and growing problem. Some pollutants, such as heavy metals like lead, are persistent, and most of these metals have high toxicity and are a significant environmental concern. Therefore, the present study aimed to remove lead from aqueous solutions by layered double hydroxide (LDH) nanocomposite deposited on magnetically activated carbon.

This experimental laboratory study was conducted on a small scale in a laboratory setting, and the samples were synthetically prepared. In this study, the effect of pH (4-10), adsorbent concentration (0.1-3 g/l), contact time (10-120 minutes), and initial concentrations of lead (5-20 mg/l) on the removal of lead ions was investigated. Process performance was evaluated based on the percentage of lead ion removal responses. Determination of the number of experiments, statistical analysis of the data, and optimization of lead ion removal were performed using the central composite design and surface-response method.

The effect of exploitation indicators on lead removal efficiency according to the analysis of variance (ANOVA) table showed that, apart from lead concentration, the rest of the indicators were significant, and respectively, the intensity of the effect and the highest value of F included LDH concentration, contact time, and pH. Lead removal efficiency was obtained 96.11% in optimal conditions with pH = 6.73, a reaction time of 67.71 minutes, a concentration of LDH nanocomposite adsorbent of 2.10 g/l, and an initial lead concentration of 10.98 mg/l. In these conditions, the model's utility was 100%. Based on the results, the highest correlation of adsorption kinetics was observed with the quadratic model. This model was selected as the most suitable to describe the kinetic behavior of LDH adsorbent deposited on magnetically activated carbon in the adsorption of lead ions from aqueous media.

The LDH adsorbent deposited on magnetically activated carbon is a suitable material for removing lead ions from aqueous solutions. Moreover, the utilization of a central composite design and surface response methodology to optimize the key variables in the lead ion removal process through adsorption is commendable.

Groundwater contamination has major effects on human health, industrial activity, agriculture, and the environment. The present study determined the concentration of lead, cadmium, arsenic, chromium, and nickel metals in the groundwater around the landfill in Juybar City and compared them with the drinking water standards.

In this descriptive-analytical study, 12 samples were sampled from four wells for three consecutive months. The concentration of heavy elements was measured using the graphite furnace atomic absorption technique (GFAA) based on standard water and wastewater methods. Also, the hardness, temperature, pH, and total dissolved solids (TDS) parameters were measured with portable devices.

Investigations showed that the average concentration of nickel, lead, chromium, and cadmium in well water was 0.0425, 0.0071, 0.0268, and 0.0117 mg/l, respectively. The average concentration of arsenic was not observed in any sample. The average temperature, hardness, pH, and TDS were measured in the range of 20-21°C, 108.66-136.33 mg/L, 7.3-7.36, and 566.25-712.33 mg/L. Also, the correlation coefficient showed a positive correlation between the metals nickel, chromium, lead, and cadmium and the parameters of temperature, hardness, pH, and TDS, as well as with each other at a confidence level of 0.01.

The amount of arsenic, lead, chromium, pH, and hardness are acceptable in the investigated wells for drinking purposes, but the amount of cadmium, nickel, and TDS is higher than the standard.

One of the problems in the health systems of the world today is the prescription or overuse of drugs. Among these, antibiotics are of particular importance. Antibiotics are a group of drugs that are widely used in medicine and veterinary medicine. Cefixime (CFX) is also one of these antibiotics. The aim of this study was to investigate the removal efficiency of cefixime from synthetic sample using catalytic ozonation with Mg-Al layered double hydroxides Doped with zeolite.

In this experimental and laboratory study MgAl-LDH/Zeolite nanocomposite was used in laboratory reactor and ozonation to remove cefixime. Effect of pH variables (5,6,7,8,9), amount of nanocomposite (0.5,1,1.5,2,2.5 g/L), initial concentration of cefixime (5,10,15,20,25 mg/L) and reaction time (5,18.75,32.5,46.25,60 min) were examined to find the maximum mineralization efficiency and response surface methodology based on central composite design (CCD) was used to design experiments, analyze data and achieve optimal conditions. Analysis of variance was also used to analyze the date. This research was done in 2021-2022.

The maximum mineralization efficiency of cefixime under optimal conditions (pH=8.70, nanocomposite value=1.76 g/L, initial concentration of cefixime=24.06 mg/L, contact time=40.76 min) is 78%, which increases the target efficiency with increasing pH and contact time.

Catalytic ozonation process with Mg-Al layered double hydroxides nanocomposite Doped with zeolite can be used effectively and efficiency to remove cefixime in aqueous media.

Today, chlorine and its compounds are the most popular elements employed for disinfecting water and wastewater due to their flexibility, cost-efficiency, and ease of use. This research aimed to optimally produce active chlorine by the electrochlorination method using titanium and platinum/titanium electrodes.

This experimental study was conducted in a batch flow of an electro-chlorination cell. The experimental design was performed using the Box Behnken method with a sample size of 34 experiments. The production of active chlorine was evaluated and compared on various operating factors, including current density (10-60 A/dm2), sodium chloride concentration (50-250 g/L), reaction time (5-120 min), and two types of anode electrodes of titanium and platinum/titanium and 316 cathode steel.

The results showed all four operating parameters had a significant effect on the active chlorine production and the highest effectiveness was related to electrolysis time, followed by current density, sodium chloride concentration, and anode electrode in descending order. The optimal operating conditions provided by the model for chlorine production included the electrolysis time of 120 min, current density of 60 A/dm2, concentration of sodium chloride of 187 g/L, and type of platinum/titanium anode electrode and 316 cathode steel electrode, which resulted in active chlorine of 65.95 g/L.

This method can be used as an effective method to produce chlorine to disinfect water and wastewater in treatment plants, and if replaced with gas chlorination systems, the safety problems of chlorine gas capsules will be solved.

With the expansion of urbanization and the development of industry, environmental pollution, including sources of drinking water to heavy metals, has become a global problem. Therefore, the present study was conducted to measure the concentration of lead and cadmium in the water of Gorgan distribution network.

This is a descriptive cross-sectional study in which the concentrations of heavy metals lead and cadmium were measured in 25 different stations of the Gorgan drinking water distribution network from April to September 2018 by atomic absorption device. Statistical analysis was used from SPSS ver 22 software. Also, zoning maps based on the concentration of these two metals were prepared by Geographic Information System (GIS) software.

The results of measuring the lead and cadmium concentration showed that all measured values are less than national and international standards. In general, the average concentrations of lead and cadmium were 4.38 and 0.1 μg/L, respectively. The results of Kruskal-Wallis test showed that there was a significant difference (p <0.01) between the concentrations obtained from lead metal in different months. Additionally, the distribution map of this lead and cadmium exhibited that in the central areas and some border areas, the concentration of these two metals is higher.

According to the obtained results, it can be seen that the concentration of heavy metals lead and cadmium in the water of Gorgan distribution network is within the permitted standards.

The presence of many synthetic dyes in aqueous solutions can cause carcinogenesis and mutagenicity and affect human health. Reactive Red 198 is one of the types of azo dyes with complex structure, toxic, carcinogenicity, mutagenicity properties, and tolerable in the environment, which is discharged to the environment through the sewage of textile industries. This study was performed to determine the mineralization of 198 reactive red dyes by the hybrid advanced oxidation process UV/US/H2O2/O3 from colored wastewater using central composite design.

In this descriptive-analytical study several factors affecting on dye mineralization process including the presence of ozone gas and ultraviolet rays (UV) as well as the initial dye concentration, Ultrasound (US), contact time, pH, and hydrogen peroxide were investigated. Experimental design and optimization were performed by design of experiment software using central composite design and its optimal conditions were determined.

The maximum dye degradation efficiency of 100% was performed under optimal conditions including initial dye concentration of 200 mg/L, reaction time of 34 minutes, hydrogen peroxide concentration of 27 mg/L and pH=9 in the presence of ozone gas flow, ultraviolet rays and ultrasonic waves. Also, the influence of factors on dye removal including ozone, UV, initial dye concentration, US, contact time, pH, and peroxide were  58.8%, 19.3%, 2.3%, 1.5%, 1.1%, 0.6 %and 0.2 % ,respectively.

UV/US/H2O2/O3 hybrid process with advantages such as performance and high speed can be recommended for wastewater treatment in various industries.

Paraquat (PQ) is the third most widely used herbicide in the world. This herbicide has the potential to damage cell membranes by lipid peroxidation and free radical attack. In this study, ZnO /rGO (ZG) heterogeneous photocatalyst was used for oxidation of PQ herbicide in aqueous solution under ultraviolet light irradiation.

In this experimental study, EDS, FE-SEM, BET, XRD, and FTIR analyzes were performed to determine the characteristics of synthesized catalyst. Effect of operating parameters, including solution pH, catalyst concentration, rGO percentage loading, PQ concentration, and UV-light intensity on degradation of PQ was studied in batch mode. Residual concentration of PQ and type and toxicity of intermediate compounds were measured by HPLC and GC-MS, respectively and toxicity test was done by Daphnia Magna. Studies on reusability of catalysts, effect of radical scavengers, and inorganic anions were also performed.

Under optimum conditions (pH=7, catalyst loading=10%, catalyst concentration=0.5 g/l, PQ concentration= 10mg/l, and UV-light intensity=220 mw/cm2), degradation and mineralization rate were 91.61% and 51% in 120 minutes, respectively. Radical scavenger experiments showed electron as the most effective factor in PQ oxidation process in ZG/UV system. In samples of agricultural run-off, degradation efficiency was 58.27%. Biotoxicity test also showed that toxic unit in pesticide-containing samples was 61.72 in raw samples that decreased to 12.19 in treated samples after 96 hours.

ZG/UV process has high efficiency and excellent catalytic activity, so, it the can be successfully used to degrade organic pollutants, especially pesticides, in wastewater.

Ammonia in form of ammonium ions is toxic and could decrease the dissolved oxygen in water and endanger the aquatic life. The aim of this study is the removal of ammonium using oxidation and adsorption by catalytic ozonation and clinoptilolite zeolite, respectively.

The research method is Experimental. First, optimal pH of ammonium adsorption on carbon catalyst (5 g/L), Garmsar and Firoozkooh zeolites and oxidation were determine. Then, in catalytic ozonation process, the effect of other variables on ammonium removal efficiency such as the concentration of carbonic catalyst (0.5- 50 g/L) and the reaction time were investigated. Then the effect of retention time and adsorbent concentration on adsorption of the remaining ammonium and nitrate produced by the oxidation process using zeolites and their modifications were determined.

Resuts:

 The results showed that optimum pH for the ammonium adsorption process by carbon catalyst, catalytic ozonation and zeolite was 8, 9 and 8, respectively. However, the optimum pH 4 was determined for nitrate removal. The highest ammonium absorption capacity was related to natural Firoozookh zeolite and 18.5 mg/g, and the effect of ligand and acid modification decreased 12 and 14% of absorbed capacity, respectively. It is also, the highest nitrate removal efficiency was related to Garmsar ligand modified zeolite (98%) and an absorption capacity of 11.2 mg/g. In the COP/absorption process the concentration of ammonium was decreased to 0.6 m /L.

This method effectively eliminates ammonium, and the modification of zeolite with cationic surfactant increases the efficiency of nitrate removal and the concentrates of all pollutants are brought below standards.

Iodine is one of the most important essential micronutrients throughout life. Salt is the most important and inexpensive iodized foods in Iran. This study aims to investigate the concentration of iodine of salt in Gorgan and compare it with standards. This study was descriptive-analytical. The sampling was performed on 11 brands of iodized salt in Gorgan,s stores. The iodine content was measured by titration with three replications. The data were analyzed using SPSS software. In this study, the lowest average iodine concentration was observed in the K brand (15.05 µg/g). It did not meet the Ministry of Health standards (30-60 µg/g and 20-50µg/g). It met the WHO, UNICEF, ICCDD standards(15-55µg/g). Also, the brand of J (21.68 µg/g), F (24.62 µg/g), I (28.23 µg/g), and E (23.62 µg/g) did not meet the new standards of the Ministry of Health. The amount of iodine in the salt can be due to its quality in the production stage (e.g. purity) and the time interval from production to consumption. Therefore, continuous monitoring is very important in the chain of production and distribution timely.

Air pollution has been recognized as the most important environmental risk factor worldwide. Benzene which is one of the four pollutants attributed to BTEX (Benzene, Toluene, Ethylbenzene, and Xylene) has been proven to be a carcinogenic component. These pollutants can be easily absorbed and taken into the body via inhalation. With this background in mind, the present study aimed to investigate the concentration of benzene and its zoning in Tehran air using Geographic Information System (GIS)  within 2016-2017.

In the present study, 26 sampling stations were selected in different parts of the city and sampled in four seasons to determine benzene concentration, as well as other meteorological parameters, such as temperature, humidity, and wind velocity. Thereafter, the obtained data were analyzed in SPSS software (version 22) using the one-way analysis of variance and correlation. Subsequently, modeling of pollutant distribution was performed using ArcGIS software. 

The obtained results demonstrated that in terms of location, the maximum and minimum annual mean concentrations of benzene were calculated at 45.12±15 and 12.36±8 μg/m3, respectively, in the center and north of the city. Temporally, the maximum and minimum values were measured at 47±17 µg/m3 in autumn and 9.82±7 µg/m3 in spring, respectively. Statistical analysis revealed that emission of this pollutant showed a significant relationship with geographical direction and wind velocity (P<0.01).

The average annual concentration of benzene in different geographical areas of Tehran was higher than the standard values of clean air. Therefore, it is suggested that fundamental measures be implemented to control this chemical compound.

Olive Mill Wastewater (OMWW) is one of the most polluted sanitary wastewaters that its ineffective treatment will cause severe pollution of the environment. In this study, OMWW treatment wasinvestigated using combined electrocoagulation and novel advanced oxidation process. Biodegradability, efficiency and kinetics of removal of turbidity and organic matter from the OMWW by applying the operational parameters of electrocoagulation such as current density (0-0.77 A/dm2), type of anode electrode, reaction time (0-45 min) were investigated. Various types of advanced oxidation processes were performed to determine the the efficiency of removal of TOC and kinetics and biobegradability. The optimum condition for removing turbidity, BOD, TOC and consumed Iron anode electrod in electrocoagulation were 78%, 57%, 72% and 583 mg/ per liter of wastewater, respectively. Thus, the kinetic of TOC removal was first-order and was 0.027 min-1. The TOC removal efficiency of pretreated OMWW in oxidation processes of US, H2O2, SOP, O3 / H2O2, COP, COP/US and H2O2/COP/US were measured as 8%, 15%, 20%, 25%, 61%, 68% and 75%, respectively. The highest biodegradability index (BOD/TOC) in the COP/US/H2O2 process was increased 1.5 times. The advenced oxidation process of COP/US/H2O2 follwed by electrocagulation demonstrated an effective treatment of OMWW and improved its biodegradability. Therefore, this process can be used for efficient treatment of OMWW in olive and similar industries.

Previous epidemiological studies suggested a close correlation between suspended particles and the prevalence of respiratory diseases, cardiovascular problems, cancer, and mortality. Moreover, it was reported that the city space contains pollutions of motionless and moving sources. Therefore, the aim of this study was to determine the concentration and release status of PM10 and PM2.5 particles in the air of Gorgan, Iran in 2016-2017 and to provide effective solutions. In this descriptive cross-sectional study, the concentration of air pollutants in Gorgan was measured at eight stations in different parts of the city for one year during July 2016-June 2017. Afterwards, the results of monthly PM2.5 and PM10 measurements by the portable device were modeled following the calculation of the quality index and estimation of their effect on health in the Geographic Information System using the Air Quality Index (AQI) Calculator software. In addition, the measurements were compared with national and international standard values. Furthermore, solutions were provided for reducing pollution. Our findings demonstrated that the highest amount of PM2.5 and PM10 were recorded in December (116 and 76 μg/m3) and the lowest was in April (40 and 34 μg/m3). The results of one-way analysis of variance revealed a significant difference in the mean concentrations of the two particles between months. According to the results of this study, air inversion in cold seasons was effective in the concentration of these pollutants. The annual mean of PM10 and PM2.5 was reported as 41 and 30 μg/m3, respectively. The latter means were lower and higher than the EPA standards of 50 and 12 μg/m3, respectively. The results of the current investigation showed that the highest AQI was related to PM2.5 in the central regions of the city, Municipality Square, and Mazandaran Square. In addition, the highest PM10 pollution was measured in the central and southern parts of the city. This could be attributed to the high density of cars, which is the most important factor in the production of particles in cities.

Catechol is one of the most common compounds in the industrial wastewater including oil and petrochemical, pesticides industries. The drainage of these industries leads to aquatic organisms poisoning and adverse effects on the environment. Therefore, this study aimed to evaluate the effects of catechol toxicity changes before and after the catalytic ozonation process by Daphnia Magna bioassay. This study is an applied research in which the toxicity of catechol and its products from degradation was evaluated by bioassay method during the Catalytic ozonation process. First stock solution was prepared at concentration of 250 mg/l followed by preparation of 10 samples that each contained 0 (control), 0.5, 1, 3, 6, 12, 25, 50, 75 and 100% of volume of primary solution. Initial samples were prepared from reactor effluent in the same volume. Based on the standard method, 10 Daphnia infants were added to prepared samples. Samples were evaluated after 24, 48, 72 and 96 hours. Finally, lethal concentration (LC50) and toxic units (TU) were calculated using probit analysis. According to the results, LC50 (24 hours) of raw effluent with an initial concentration of 250 mg / L of catechol increased from 13.30 ml/100 ml to 33.9 ml/100 ml after 60 minutes treatment. Consequently, the toxicity unit decreased from 7.51 TU to 0.9 TU which means that the toxicity dropped by 88%. Finally, the toxicity of treated effluent decreased during catalytic ozonation process to degradation of catechol. Bioassay is a simple and effective way to evaluate the toxicity potential of Catechol to discharge it to surface water. Based on the bioassay by Daphnia Magna, Catalytic ozonation process is able to reduce the toxicity of catechol by degradation this compound and breaking into other products.

One of the important problems in the management of waste is the health and environmental hazards of the leachate leakage of urban waste landfills to groundwater. This research aimed to investigate the improvement of the landfill properties using recycled polymer. In this study, PET: Polyethylene Terephthalate and clay were mixed with the ratio of 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1 wt%. Moreover, Moreover, its effect on the quality parameters of clay, including consolidation, settlement, shear stress, adhesion, and infiltration were determined in soil mechanics laboratory located in the city of Gorgan. All experiments were conducted based on American Society for Testing and Materials. Results showed that the internal friction angle in clay and clay composed with polymer were 20.93 wt% and 30.3 wt%, respectively. Moreover, the compaction of clay decreased from 0.163 g/cm2 to 0.110 g/cm2. Permeability results showed that the use of PET decreased the permeability of soil from 1.82 E-3cm/min to 1.57 E-3cm/min. The use of recycled polymer can improve the soil conditions of landfills in terms of permeability and resistance to leaching, which could reduce the volume and the recycling process of waste. Moreover, this issue contribute to the quality and strength of the substrate to prevent environmental contamination as well as groundwater polution.

Ceftriaxone is widely used for healing the infectious diseases. Not being treated in hospital wastewater treatment systems, this antibiotic has the possibility of entering into the aqueous environmental and the danger of microbial resistance in these environments also increases. This study aims to examine the efficiency of catalytic ozonation process by using magnesium oxide nanoparticles to remove ceftriaxone from aqueous solutions. In this study, the effect of pH, ozone dose, reaction time, catalyst dose and initial antibiotic concentration for ceftriaxone removal were studied using a cylindrical-shaped experimental reactor through semi-batch method. The residual concentration of ceftriaxone was determined by spectrophotometer. The experiment was carried out based on the one factor at a time method and finally the optimum efficiency of ceftriaxone removal and its desired conditions were determined. The best condition of the reactor obtained in pH 11, the catalyst dose of 1g/l, ozone dose of 18.384mg/min, pollution concentration of 10mg/l and reaction time of 30 min which showed 86% of ceftriaxone removal. Due to an increase in ozone retention time, the use of magnesium oxide nanoparticles in ozonation process also increased the antibiotic removal. It leads to a decrease in treatment costs because of a decrease in ozone consumption in an industrial scale.

Water and wastewater resources contamination, caused by the wastewater discharged from industries, is considered a major threat to human and environment health. Catechol is one of the usual phenolic compounds in wastewater of various industries such as oil and petrochemicals, plastics, resins, and etc, which is highly toxic and resistant to degradation. Therefore, the purpose of this study was to determine the intermediate compounds and mineralization of catechol in oxidation process with ozone.
Material and This study was a laboratory research which investigated the effect of variables such as solution pH (2-10), reaction time (0-60 min), initial concentration of catechol (50-1000 mg/l),and radical scavenger on the efficiency of ozonation process. The residual concentration of catechol was measured by HPLC at 275 nm. Also mineralization and degradation of catechol were determined by TOC (Total Organic Carbon) and COD (Chemical Oxygen Demand) tests. Intermediate compounds of ozonation process were measured by GC/MS and were presented as tables and graphs.
Optimum pH for ozonation process was 10. The maximum process efficiency at pH 10 and the contact time of 60 min was 96.20%. Kinetics of catechol degradation followed the first order model. The TOC and COD removal after the contact time of 60 minutes were determined about 78% and 84.4%, respectively. Radical scavenger of tert-butanol (1gr) and sulfate (1gr) reduced the removal efficiency of catechol 12.61% and 0.13%, respectively.
The results showed that the removal of catechol in the optimum condition such as alkaline pH has better efficiency due to the production of hydroxyl radicals. As a result, it seems ozonation process is an effective method for degradation and mineralization of catechol from industrial wastewater.

Background and Presence of natural organic substances in surface water supplies could be harmful and have adverse effects on drinking water treatment due to many practical and hygiene reasons. This study aimed at investigating the efficiency of catalytic ozonation process in removal and mineralization of humic substances in water resources in north of Iran.
Water treatment plants in Gorgan and Sari were studied (2017). First, the concentration of humic substances was measured in water. Then catalytic ozonation process (COP) of the water samples were performed using semi-continuous cylindrical reactor. The effects of some parameters such as reaction time (0-60 min) and catalyst dosage (0 and 3 g/L) on removal efficiency and mineralization of humic substances were investigated. After determining the kinetics constants of reactions, the removal efficiencies were compared between COP and single ozonation process (SOP).
The concentrations of humic substances in water samples in Sari and Gorgan were 15.22 ± 5.39 and 18.62 ± 6.16 mg/L, respectively. The efficiency of removal of humic acid and its mineralization in the COP process under optimal conditions for Naharkhoran, Sari Salim Bahram, and Alangdare water treatment plants, were 100, 84.21, 88.18%, and 100, 83.4, and 78.03%, respectively. The reaction kinetics were first-order and their rates were 2.6, 2.9, and 3.7 folds more than those of the COP process, respectively
Using magnetic activated carbon catalyst coupled with ozonation process, compared to SOP, is 40% more efficient in removal of humic substances. Also, by reducing the ozonation time and the easy recovery of the catalyst and improving the process efficiency it reduces the costs.

Discharge of industrial wastewater containing Catechol has adverse effects on human and environmental health. Purpose of this study was to determine the effects of catechol toxicity before and after advanced oxidation process (ozonation process) by bioassay test with Daphnia Magna.
This study is an applied research in which the toxicity of catechol was determined by Daphnia Magna bioassay test during the ozonation process. First, Catechol stock solution was prepared at a concentration of 250 mg/L. Then, 10 samples were prepared that each contained 0 (control), 0.5, 1, 3, 6, 12, 25, 50, 75 and 100% of volume of primary solution. Initial samples were prepared from reactor effluent in the same volume as those of the samples. According to standard method, 10 Daphnia infants were added to each sample. The samples were observed after 24, 48, 72 and 96 hours. Finally, lethal concentration (LC50) and toxicity unit (TU) were calculated using Probit analysis.
According to the results, Daphnia magna was affected by the toxicity of catechol. LC50 (24-hour) for raw effluent was increased from 13.30 mL/100 mL to 30.4 mL/100 mL after 60 minutes Treatment. The toxicity unit was decreased from 7.51 TU to 3.29 TU accordingly, showing reduction of 56% in toxicity. The toxicity of the treated effluent decreased during ozonation process of catechol.
Based on the bioassay test, ozonation process was able to reduce the toxicity of catechol. Therefore, this process can be used as an option to treat wastewater that contains catechol.

Background and Environmental pollution by heavy metals and their transfer to soil and crops are a growing global problem. This study aimed to measure the concentrations of heavy metals in wastewater and sludge wastewater treatment plant in Gorgan, Iran.
In this cross-sectional study, 176 samples of effluent, and returned and dried sludges were analyzed in wastewater treatment plant in Gorgan, during six months in 2016. The concentration of Pb, Cd, Ni, and Cr were determined using polarography (Metrohm797 AV) and furnace atomic adsorption spectroscopy (AA 240 Varian Co.) in the laboratory of Health Faculty in Golestan University of Medical Sciences.
The average concentrations of Pb, Cd, Ni, and Cr in the effluent were 0.105 ± 0.06, 0.0089 ± 0.008, 0.095 ± 0.108, and 0.102 ± 0.175 mg /L, respectively. The concentrations of Pb, Cd, Ni, and Cr in returned sludge were 323.48 ± 217.65, 2.44 ± 3.3, 354.14 ± 322.79, and 388.53 ± 252.59 mg /kg of dry weight, respectively. Also, in dried sludge, the average concentrations of lead, cadmium, nickel, and chromium were 58.48±2.67, N.D, 30.31±1.98, and 506.25±813.81 mg/kg of dry weight, respectively.
The concentrations of heavy metals in wastewater effluent and dried sludge, except in returned sludge, were below the standards. Due to long-term use of effluents, necessity of treatment of other parameters, and the effect of bioaccumulation of metals in sludge, caution should be taken for their agricultural application. Also, because of importance of this type of contaminants in soil and food products, continuous monitoring by water companies is highly necessary.

Nowadays the releases of some of the contaminants in the environment that have a high half-life remain in the nature, enter the food chain, and ultimately transmitted to humans. Presence of these materials in our body causes various complications including mutations in various genes and carcinogenesis. In recent years, many new advanced oxidation process (AOP) were introduced that their process is based on hydroxyl free radicals, which have great potential for the decomposition of various organic material. In this paper, various methods of chemical treatment of refractory materials, with emphasis on advanced oxidation of industrial wastewater have been investigated and their cons and pros are discussed.
This paper was a review article in which using key words of advanced oxidation processes, degradation, treatment, wastewater and recalcitrant contaminant in scientific search engines including Science Direct, Google Scholar and Scopus, the related articles were collected and analyzed in the period of 1993 to 2016.
Findings: In these methods, in addition to the higher oxidation potential, are very different from conventional methods in the operating conditions and adverse side effects for the environment. In general, ultrasonic waves and advanced oxidation technology such as plasma, Fenton, photo-Fenton, oxidation by peroxide, ozone and photo catalytic process such as O3/UV have been used to remove contaminants from water resources. Generally, some factors affecting AOP processes are pH, temperature, concentration and type of pollutant, type and concentration of catalyst. In addition, advanced oxidation processes can be used to degrade residual pollutants that remain after the purification process in the wastewater. As a whole, AOP is used as a pre-purification for residual pollutants having toxic and recalcitrant materials.
Generally, these methods have the advantages of high kinetics and purification efficiency. However, due to high operational costs and complexity of the process, they rarely are used as a single process for treatment of sewage and often used in conjunction with other treatment processes.

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.

Background and Phytic acid plays a major role in reducing the bioavailability of minerals in food. The aim of this study was to evaluate the effect of controlled sourdough fermentation on reduction of phytate content in dough and bread produced by whole wheat flour containing Lactobacillus plantarum and Lactobacillus brevis.
This experimental study was carried out as a joint project in Golestan University of Medical Sciences and Gorgan University of Agricultural Sciences and Natural Resources. After isolation of two dominant lactobacillus isolates from whole wheat sourdough and their molecular identification, the effect of controlled sourdough fermentation (dominant isolates were used as starter culture, under treatments (as separate or mixed with equal proportions) of 28, 32, 36 °C fermentation temperatures and 16, 24, 32 h fermentation times) was examined on phytate content of produced dough and bread, using a spectrophotometric assay based on the measurement of iron.
Sequencing of PCR products led to identification of Lactobacillus plantarum and Lactobacillus brevis as the dominant lactobacillus isolates from whole wheat sourdough. According to statistical analysis, by increasing fermentation time and temperature, the amount of phytate significantly decreased in dough and bread produced by each of dominant isolates (P≤ 0.05). Furthermore, mixture of lactobacillus as starter culture was more effective on phytate reduction compared with using them separately.
Our results showed that controlled fermentation of whole wheat sourdough have significant effect on reduction of phytate and increasing the bioavailability of bread minerals.

Background and Many conventional disinfection methods of effluents raise some health, efficiency and economic concerns. In order to increase the efficiency of disinfection of real effluent, in this study, the catalytic ozonation process was performed and economically compared with chlorination.
Magnetic activated carbon was used as acatalyst in a semi-continuous reactor for disinfection of effluent of municipal wastewater treatment plant in Bandargaz, Iran in 2015. The efficiency of disinfection was determined by thermo-tolerant coliform as indication, and the effect of parameters such as catalyst concentration (0, 0.5, 1, 2, and 5 g/L), initial number of coliforms, contact time (1, 2, 5, 10, 20 and 40 min) and catalyst reuse on disinfection process was evaluated. Finally economic comparison was done with the chlorination.
The results showed that the efficiency of disinfection was increased by increase in the concentration of carbon nano-composite and contact time; at 1 g/L concentration of Catalyst about 1.99 log reduction was observed after 2 min exposure time in which the effluent standards were obtained; while 1.91 log reduction of micro-organisms was measured for single ozonation. The first-order kinetics constant of single ozonation (0.42 min-1) showed an approximately 9-fold increase when the catalyst (2 g/L) was added to the solution. After 7 times reuse of nano-composite, the diminution of efficiency was negligible (1.5%); and more than 57% fall of the cost was observed in a 5-year operational period compared with chlorination.
The catalytic ozonation with the new catalyst of effluent could effectively disinfect the effluent in a short-contact-time, and due to economic considerations it can be used as an effective and economical method in wastewater treatment plants.

Background and Molasses is colored, toxic and non-biodegradable compound which is found in the wastewater of fermentation industries. This study investigated the kinetic and efficiency of molass dye removal and mineralization in the yeast wastewater using nanocomposite catalysts in ozonation process.
The catalytic ozonation process (COP) of colored effluent of biological treatment of yeast production factory was carried out using semi-continuous flow cylindrical reactor and the effects of operational parameters such as initial pH value (4-10) and reaction time (5-60 min) on removal efficiency of dye and mineralization were investigated. After determining the kinetic parameters of reaction, the effects of some other parameters such as adsorption and reuse of the catalyst were calculated and the efficiency was compared with single ozonation process (SOP) and granular carbon as catalyst.
The removal efficiency of dye of molass factories effluent and its kinetic, at the condition of initial dye concentration 4521 ADMI, catalyst concentration 2 g/L and 60 min reaction time were 95% and 0.045 min-1, respectively; while these parameters in SOP and granular activated carbon as catalyst were 71% with 0.018 min-1 and 86% with 0.028 min-1, respectively. But, the mineralization and its kinetic in COP were 74% and 0.023 min-1, respectively, in which initial TOC was decreased from 510 mg/L to 132 mg/L.
The nanocomposite was found to have the best efficiency in dye degradation and TOC removal and it is easy to recover and reuse over and over by magnet. The main mechanism of dye degradation in COP was chemical oxidation and less occurred by adsorption.

Selling of bottled water has been increasing around the world, because many people believe that this type of water is an ideal option for drinking particularly for the immunosuppressed people. Thus, we aimed to investigate fungal contamination in bottled water in Gorgan, Iran
Four-hundred bottled water samples belonging to 10 famous brands were collected from different retail outlets in Gorgan, from May 2014 to April 2015. Fungi identification was performed by Subdextroz agar and Potitodextroz agar. Data analysis was performed by chi-square test (P Findings: Rodotrolla fungal spp was identified in 164 (41%) of all tested samples. About 32% of contamination was related to 60 days after bottling, and its rate was the same in small and big bottles. All brands were tainted but the difference was not significant.
Based on the results, some water bottles have fungal contamination that is in contravention of bottled water regulation. Hence, it is a necessity to implement water safety plan to improve the quality of bottled water.