ali assadi

The aim of this study is to investigate some pesticides, including organic phosphorus compounds and carbamates, on tobacco leaves, which are commonly used in agricultural activities to increase crop production around the world. Humans are exposed to pesticides through residues left in fields, which have harmful effects on the body.

The study collected a total of ten samples of tobacco leaves, five from different cultivation areas in Iran and five from five different countries as imported samples. The collection was done three times to ensure that the results were reliable and consistent. To determine the residual concentration of organophosphorus and carbamate pesticides, we collected 210 samples using the QuEChER method to prepare the samples. The residual levels of 26 pesticides were measured using the GC-ECD and UHPLC-MS/MS methods.

Most samples had residual levels of pesticides below the detection limit. However, in Iranian samples, the highest average concentrations were found for Thiodicarb (μg/kg 525.2), Chlorpyrifos (μg/kg 499), Dichlorvos (μg/kg 260.3), Penconazole (μg/kg 208), Thiophanate-methyl pesticides (μg/kg 168.5). For imported samples, Thiodicarb (525.2 μg/kg) and Dichlorvos pesticides (260.3 μg/kg) had the highest average residual concentration.

Despite severe restrictions on pesticide use in the sampled specimens, residual amounts of these chemicals persist, which can contribute to the adverse health effects of smoking. Therefore, more effective monitoring and surveillance measures are necessary.

Recalcitrant organics remediation from water resources continues to be a significant environmental problem and there is a continued effort to demonstrate practicable and economical treatment options for pollution removal.

In this study, the efficiency of the permeable reactive barrier (PRB) in a column reactor using zero-valent iron (ZVI) particles and sand mixture in the removal of methyl tert-butyl ether (MTBE) from aquatic phases was investigated. The system performance was MTBE removal while initial pH,reaction time, pollutant content, catalyst load, hydraulic loading rate (HLR), and the reaction rate constant were independent variables.

The results showed that the process efficiency decreased by increasing pH, HLR, and pollutant concentration. In this case, the optimal conditions were obtained at pH = 7, HLR = 0.23 m3/m2·d, and C0 = 1 mg/L, which achieved a remarkable removal efficiency up to 90.32%. The high nitrate concentrations and hardness as intervening factors reduced process efficiency to less than 44.61 and 51.4%, respectively. The lack of interfering factors had a considerable effect on the reaction rate of MTBE reduction, which is approximately 2.65 and 4.11 times higher than that in the presence of calcium hardness and nitrate, respectively.

The PRB technology can be suggested as a reliable and robust system to remediate groundwater containing hydrocarbons based on filling media and hydraulic conditions.

The elimination of methyl tert-butyl ether (MTBE) from water resources remains a main environmental concern. In the present study, photo-assissted process for removal of MTBE was examined in the solutions containing C-N-TiO2 nanoparticles under UV irradiation in the batch mode.

The effects of operational factors such as pH, initial catalyst concentration, and initial MTBE concentration on MTBE removal was investigated.

The optimum degradation condition for MTBE was obtained at pH 7, catalyst load of 100 mg/L, air flow rate = 0.1 L/min and C0 = 5 mg/L with 73 percent degradation of MTBE at 60 min. In addition, Analytical profiles on MTBE removal were based on the first-order kinetics model. However, the removal rate decreased by increasing initial concentration of MTBE.

The findings showed that UV/C-N-TiO2 system is an efficient method for MTBE degradation from aqueous solution.

Zinc production due to applying mineral soils as raw material and high rate of tailings and wastes lead to environmental and health challenges, such as total suspended particle (TSP) emissions.

This was the first study to monitor TSP concentration fluctuations and location variability in Zanjan zinc industrial park (ZZIP), Iran for 11 months. Nine stations equipped with an LVS were selected for TSP sampling from air simultaneously. Sample analysis was performed in the laboratory using gravimetric methods and data depicted by ArcGIS to recognize spatial distribution.  

Changes in TSP concentrations were within the range of 30.17-2,692.82 μg/m3 and exceeded the EPA/WHO guidelines in more than 98% of the cases. Spring and winter showed the highest levels. The main influential factors in the TSP concentration were industrial activities, vicinity to the depot site and main streets, the speed of passing vehicles, and the dominant wind direction.

Despite recent attempts to control TSP, the concentrations remain high and alarming. Therefore, special attention must be paid to the health issues affecting staff and residential groups and implementation of more effective control mechanisms.

This study evaluated the effects of coating of soybean meal (SMB) with the fat enriched in saturated fatty acid (SFA) and zeolite on rumen degradable dry matter (RDDM), rumen degradable protein (RDP) and intestinal digestibility of protein. Treatments were (1) SBM, (2) SBM protected with 40% SFA, (3) SBM protected with 38% SFA and 2% zeolite, (4) SBM protected with 50% SFA, (5) SBM protected with 48% SFA and 2% zeolite. To obtain the RDP fraction, samples were ruminally incubated for 16 h. The intestinal digestibility of crude protein was performed by three-step in vitro procedure. The results showed that SBM protecting with SFA reduced protein solubility compared with untreated SBM (P=0.002). The RDDM and RDP were decreased (P<0.05) with increasing fat level in the product. Using 2 % zeolite significantly decreased (P<0.05) RDP. There were no significant differences between SBM and SBM protected treatments in intestinal digestibility. It was concluded that protection of SBM with SFA decreased of RDDM and RDP, while RDP values showed more decrease with the inclusion of zeolite in the fat matrix.

In recent years, the increase in car production, population growth, urbanization and significant expansion of the use of private vehicles has led to the development of more and more carwash facilities in all cities. Regarding the carwash wastewater pollutants, treatment of such wastewater can be a big help in protecting surface and groundwater resources. The wastewater needed for this research was taken from the output of carwash using hand washing method and composite sampling. The aim of this study was to determine the efficiency of combined chemical coagulation and UV/H2O2 processes in treatment of carwash wastewater. To reduce the settleable solids, samples underwent a 2-hour settlement. Then in the first step of coagulation process, the optimum conditions for pH and the ferric chloride dose were obtained using jar test. The effluent of coagulation stage was introduced to UV/H2O2 reactor under the influence of ultraviolet radiation. Finally, required parameters such as COD and BOD5 in the effluent of oxidation process were measured at the designated times. Results showed that the COD removal efficiency of 70% and 93.2% was achieved in coagulation and UV/H2O2 process, respectively. The overall efficiency of this system based on COD and BOD5 removal was obtained as 98% and 97.5%, respectively. Overall, the recommended combined system is effective and robust to treat carwash wastewater to meet the standards of effluent discharge.

Due to the wide use of swimming pools and the necessity of maintaining the health of swimmers and controlling health issues, management and monitoring of such sites are necessary and necessary for compliance with established standards by competent authorities. The aim of this study was to evaluate the physicochemical and bacteriological indices of swimming pool water in Zanjan in 1995 This study was descriptive-analytical and all of the active swimming pools were sampled during the summer and autumn seasons. Physical and chemical parameters such as air and water temperature, turbidity, residual free chlorine content, electrical conductivity, oxidation and regeneration potential (ORP) and bacteria including total coliforms and fecal coliforms, plate counting of heterotrophes, stool streptococci, Staphylococcus aureus and Pidmonas Aeroginosa was studied Among the microbial parameters of Pseudomonas aeruginosa and fecal coliforms, the plate count of heterotrophs was 64%, 26.9% and 12%, respectively, and were at an unsatisfactory level compared to the standard. This indicator was obtained for parameters of turbidity, water temperature, air, pH and free chlorine 98%, 94%, 88.9%, 79.6%, 41.7%, respectively Physicochemical and bacterial parameters are in poor compliance with the national standard. Trainers instructors and managers of swimming pools are responsible for basically exploiting pools, implementing retraining courses for health inspectors, controlling routine operation and interventional parameters such as turbidity and temperature, and Effective on the disinfection process and the use of digital and up-to-date digital imaging devices has a significant impact on the water quality of the pools

The objectives were to evaluate effects of adding alfalfa hay (AH) as moisture absorbent to corn forage upon ensiling on silage fermentation, effluent production and performance of late lactating Holstein cows. Corn forage with the initial dry matter content of 22%, left untreated or ensiled with 5 and 10% AH, on a fresh weight basis, for 90 days. Silage DM linearly increased, while effluent production, pH, NDF and water-soluble carbohydrates concentration linearly decreased as AH inclusion rate increased (P<0.05). An incomplete 2×3 Latin square experiment with nine late lactating Holstein cows consuming the above-mentioned silages showed similar nutrient intake and milk production and composition while a linear increase in organic matter digestibility with AH inclusion (P<0.05). Total chwing and eating times were unaffected, however, chewing and ruminating time spent /kg DM linearly decreased as AH inclusion rate increased (P<0.05). Ruminal pH and concentrations of VFA were similar across treatments. Results showed a strong effect of AH on reducing effluent from immature corn silage without having an adverse effect on silage fermentation and dairy cows’ performance. Using AH for controlling of effluent from corn silage is recommended.

Corrosion and scaling of piping are a main issue in the operation of the drinking water network. Corrosive water can cause the intrusion of heavy metals into water and can lead to affect public health. This study aims to present the corrosion and scaling potential of Zanjan drinking water network that is located in north west of Iran. This descriptive cross-sectional study was carried out using calculation of Langlier Saturation Index (LSI), Ryznar Stability Index (RSI), Puckorius Scaling Index (PSI), and Aggressiveness index (AI). Thirty six samples were taken from all over the city within two seasons, summer and autumn in 2016. To reach this goal following parameters such as pH, total dissolved solids (TDS), alkalinity, calcium hardness, magnesium, total hardness, temperature and electrical conductivity (EC) in all samples were measured in the laboratory. The mean and standard deviation values of LSI, RSI, PSI and AI indices were equal to -0.62±0.18, 8.26±0.29, 8.04±0.51 and 11.5±0.24, respectively in summer and -0.83±0.12, 8.70±0.33, 8.00±0.29 and 11.15±0.25, respectively in autumn. According to all indices the results have shown that Zanjan drinking water is a mild corrosive. Finally, it is recommended that water authorities must be adjusted effective parameters such as pH of treated water at the beginning of the network in order to corrosion control.

 

This study has been focused on the relationship between cementation and dissolution processes with depositional facies and unconformity surfaces of upper part of the Sarvak Formation (Cenomanian-Turonian and mid-Turonian unconformity surfaces), using core and thin section data from a key well. Based on petrographic studies, six facies related to lagoon, slope and open marine sub-environments were identified. The results of this study indicate that the dissolution and cementation processes have been occurred in several diagenetic stages. Dissolution of unstable skeletal grains under the effect of eogenetic diagenesis created extensive vuggy porosity. In addition, during the telogenetic diagenesis and in relation to unconformity surfaces, vuggy pore types within the grains and rock matrix have been developed. The distribution of calcite cement within the reservoir shows a close relationship with initial mineralogy of the skeletal grains, size of dissolution vugs as well as density and the width of the factures. Calcite cement occurs as drusy and blocky forms and with meteoric and burial source within the dissolution vugs and microfractues. Within the Turonian interval that has been situated below the mid-Turonian unconformity, due to the mud-dominated nature of lagoon and open marine facies, dissolution and cementation have insignificant distribution, and calcite cement is mostly observed in relation to fractures. In contrast, in the interval below the Cenomanian-Turonian boundary, these processes have more distribution due to the frequency of grain-dominated facies. The results of this study show that the nature of depositional facies has significant role on distribution of cementation and dissolution processes within the Sarvak Formation.

Nowadays, underground water is the main source of drinking water that contamination to organic pollutants such as MTBE is an important issue. One of the suitable methods for these types of pollutants is the advanced oxidation methods. Advanced oxidation processes (AOPs) are involved in the production of highly reactive hydroxyl radicals that oxidize organic matter such as MTBE and even lead to its full mineralization. The use of light in the presence of catalysts is one of the methods of advanced oxidation processes. Photocatalytic methods widely used for a wide range of toxic and none degradable pollutants. Recent advances in the fabrication and characterization of Nano scale materials have extensively developed research into methods for the preparation of highly effective Nano-sized catalysts for the removal of chemical contaminants. This review article discusses the work on the photo catalysis of MTBE in water using different types of photo catalysts.

The Permo-Triassic Dalan-Kangan and upper Jurassic Arab formations are important carbonate-evaporate reservoirs resulted from depositional and diagenetic heterogeneities. The objectives of the study are comparison precursor mineralogy, identification of dominant pore types and clarify the role of diagenetic processes on petrophysical characteristics and reservoir quality of the Dalan-Kangan and Arab formations in the Persian Gulf. To achieve this goal core description and petrographic study and core poroperm data from two hydrocarbon fields in the Persian Gulf were integrated. Pore system studies show that different pore types contribute to the fluid flow and production within the Dalan-Kangan and Arab formations. These pore types are inter-granular, intercrystalline, touch and non-touch vugs and microspores. The initial mineralogy of the components had a significant effect on pores system distribution and trend of the diagenesis of the two studied intervals. During the Permo-Triassic and upper Jurassic, the composition of ocean waters has been suitable for deposition of non-skeletal components with aragonite and calcite mineralogy, respectively. Thus, moldic pores in the Dalan and Kangan reservoirs and intercrystalline and inter-granular pores in the Arab Formation occur as the dominant pore types. In Dalan and Kangan formations, micropores are more frequent than the Arab Formation, which is attributed to the dominance of mud-dominated facies during the Permo-Triassic periods. Detailed diagenetic studies indicate that the studied intervals were exposed to dissolution, cementation, anhydrite mineralization, dolomitization, physical and chemical compaction and fracturing after deposition. Dissolution, anhydrite mineralization and cementation seem to have exerted the main effect on pore system properties

The Sarvak Formation with the late Albian-early Turonian age is the most prolific hydrocarbon reservoir of the Abadan Plain region. Permeability estimation in heterogeneous carbonate reservoirs; such as, the Sarvak Formation, due to the complexity of pore characteristics is challenging, and porosity-permeability relationship in these reservoirs is dependent on pore type, size and connectivity of pore systems. In this study, permeability estimation has been accomplished using the pore facies concept and empirical formula. Based on the core description, thin sections’ studies and SEM images, pore types were identified and described. Afterwards, with respect to the petrophysical nature of pore systems and their porosity-permeability relationships, four pore facies microporosity (PF-1), microporosity-vuggy (PF-2), vuggy (PF-3) and vuggy-interparticle (PF-4) were introduced. In each pore facies, an empirical formula for the permeability estimation based on porosity-permeability relationship were determined. Comparison the results with the permeability values estimated in previous studies demonstrates that the estimation of permeability on the basis of pore facies concept has higher concordant with depositional and diagenetic characteristics. Generally, the intervals with microporosity and separate vugs, due to the weak pore system connectivity, a lower value of permeability will be estimated. In contrast, the intervals with interconnected pore systems such as touching vugs and interparticle pore spaces show higher permeability in comparing with the other pore types with the same values of porosity. Regarding the importance of pore type and geometry on permeability distribution within the reservoir, permeability estimation in term of pore facies can be useful in investigating the reservoir properties of heterogeneous carbonate reservoirs.

Phenol as an aromatic hydroxyl compound are considered as a priority pollutant. Because of their stability, solubility in water and high toxicity had health important.
In the present experimental study, electrocoagulation reactor by iron electrodes are used in the presence of hydrogen peroxide to phenol removing from aqueous solutions. Effects of variables including H2O2 dosage, reaction time, pH, current density and initial phenol concentration were evaluated to estimate the efficiency of the process.
The results showed that pH and H2O2 have the most important role in the removal of phenol. Increasing of H2O2 concentrations from 0.0125 to 0.025 M increased removal efficiency from 74% to 100%. Maximum removal was achieved at pH=3. However, increasing the pH to 9 lead to reducing removal efficiency to 9.8%. Also, by increasing of current density removal efficiency was increased. But with increasing initial concentration of phenol removal efficiency was reduced.
Proxy-electrocoagulation process as an effective and robust process can be used for handling of phenol containing wastewater.

Natural organic matters (NOMs) have the main role in formation of trihalomethanes. These compounds are in natural water sources due to biological activities. In the presented study, adsorption and separation of humic acid as an index of natural organic matters using multi-walled carbon nanotubes is evaluated.
The experiments were carried out in bath adsorption reactors with different concentrations of humic acid. The effects of pH, adsorbent dose, national concentrations of humic acid and contact time as study variables were tested in separated experiments, as well as, kinetic and isotherm models of the adsorption process were determined.
The results showed that the adsorption follows Freundlich isotherm model and pseudo second-order kinetic equation. The removal percent of humic acid reached to higher than 90% with dosage of 1g/l of nanotube.
Adsorption of humic acid from water by multi-walled carbon nanotubes is an efficient alternative pretreatment method in water treatment plants.

The Sarvak Formation is one of the most important carbonate reservoirs of Iran. This study presents an integrated geological and petrophysical reservoir characterization of the Sarvak Formation in a giant oil field in the Abadan Plain, SW Iran. On the basis of porosity-permeability data, core description and petrographic studies from two key wells, flow units were identified and interpreted. To identify flow units within the Upper Sarvak Formation, three different petrophysical methods including (1) Flow Zone Indicator (FZI), (2) Pore Throat Radius (R35) and (3) stratigraphic modified Lorenz plot (SMLP) were applied. The results indicate that the FZI and R35 methods cannot efficiently discriminate the different reservoir zones and flow units for this reservoir, because of the high changes in petrophysical properties have mainly inherited from the internal geological heterogeneity. In contrast, SMLP method successfully classifies the studied reservoir into discrete flow units by considering the relationship between petrophysical properties and depositional and diagenetic features. From depositional facies point of view, the best flow units are related to talus, shoal-biostrome and shallow open marine depositional facies, while lagoon and distal open marine commonly show low reservoir quality. In low reservoir quality units, calcite cementation and compaction are the dominant diagenetic processes, while dissolution is the main agent for enhancing of the reservoir quality in the reservoir units with high quality. The results indicate that the interpretation of flow units based on the depositional and diagenetic characteristics provides the crucial insight on distribution of reservoir zones within the heterogeneous carbonate reservoirs, such as, the Sarvak Formation.

The Late Jurassic Arab Formation, as an excellent example of the classic carbonate-evaporate sequences, constitutes one of the most prolific hydrocarbon reservoir in the Persian Gulf and adjacent areas. In this study, regarding the importance of dolomite reservoirs throughout the world, and the effects of anhydrite mineralization on these reservoirs, the impact of anhydrite texture, its distribution and abundance within the dolomite intervals of the Arab Formation is investigated. In this respect, the integration of the results from core description, petrographic studies as well as core poroperm values and the mercury injection capillary pressure data have been used. The petrographic analysis indicates that there is a strong relationship between the percentage, texture and distribution of anhydrite in the reservoir. Anhydrite has been developed as uniform and patchy distribution in the reservoir with poikilotopic, nodular, pore filling and bedding textures. Generally, the reservoir intervals with the uniform anhydrite distribution are correlatable with the high percent anhydrite samples, and nodular and pore filling textures. In contrast, the intervals with patchy anhydrite cover the reservoir dolomites with low percent anhydrite and poikilotopic texture. The assessment of poroperm data and parameters extracted from the mercury injection capillary pressure tests indicates that the dolomites with patchy anhydrite, poikilotopic texture and low anhydrite content, due to the large pore throats radius, comprise the best reservoir units of the Arab Formation.

Conventional chemical coagulation is considered as the old method to color and COD removal in textile effluent. Electrocoagulation (EC) process is a robust method to achieve maximum removal.
This work was designed to compare the result of operational parameters including optimum pH and coagulant concentration for chemical coagulation with ferric chloride and alum. Also, the effect of voltage, electrolysis time, initial pH, and conductivity for EC with iron electrodes on removal of reactive red 196 (RR 196) were studied.
The results show that ferric chloride and alum at optimum concentration were capable of taking away color and COD equal to 79.63 %, 84.83%, 53%, and 55% respectively. In contrast, EC process removed the color and COD equal to 99.98% and 90.4%, respectively.
The highest treatment efficiency was obtained by increasing the voltage, electrolysis time, pH and conductivity. Increase in initial dye concentration reduces removal efficiency. Ultimately, it could be concluded that EC technology is an efficient procedure for handling of colored industrial wastewaters.

During the precipitation of Sarvak formation imprints of climate, tectonic and sea level fluctuation lead to some of the most prolific reservoirs in Zagros and Persian Gulf basins. The reservoir quality of upper Sarvak formation in Abadan plain oil fields are highly influenced by various diagenetic process. Based on core studies, petrographic analysis, well logs and properm data from two key well in a giant field, diagenetic sequence is reconstructed and the main processes effecting the reservoir quality are discussed. Three main diagenetic environments including 1- marine diagenesis (Micritization, Bioturbation, marine cementation) 2- meteoric diagenesis (mineralogy stability, recrystallization, meteoric cementation, mixing zone dolomitization, Dedolomitization, fabric and none fabric selective dissolution) and finally 3- burial diagenesis (physical and chemical compaction, burial dolomitization, fracturing, burial cementation, Silicification and pyritization and some none fabric dissolution) have affected the upper Sarvak formation after deposition. Dissolution of matrix and grain, especially aragonite shells was a main porosity creating process, and took place primarily by meteoric diagenesis. Diagenetic studies indicate meteoric environment products highly modified reservoir quality. Calcite cementation and compaction are the chief factors controlling the reduction properm whilst dissolution and fracturing have enhanced reservoir quality of the studied interval. This study resulted that distribution and intensity of diagenetic process are dominantly controlled pore systems and reservoir quality.

Titanium dioxide (TiO2)-mediated photocatalysis has been found to be an efficient method of water treatment and is capable of degrading a wide range of organic pollutants and microbial agents with high efficiency. The microorganism Pseudomonas aeruginosa is resistant to chemicals and UV irradiation. Bacteria which are resistant to UV-induced oxidative damage of the cell membrane are susceptible to photocatalytic technology. The main objective of this research was to examine the photocatalytic removal of P. aeruginosa upon UV irradiation in the presence of TiO2 nanoparticles.
Polluted water samples were prepared by the addition of P. aeruginosa colonies into water, followed by contact with UV, TiO2, or a combination of the two in separate stages. The effect of various parameters, including contact time, pH, and TiO2 concentration, on reaction efficiency was examined.
The highest efficiency of bacterial disinfection was achieved with UV irradiation in the presence of TiO2 nanoparticles, with complete (100%) removal of P. aeruginosa observed upon irradiation for 60 min in the presence of 0.4 g/L TiO2 under conditions of neutral pH.
The results of this study suggest that from a technical and economic perspective, the UV/TiO2 process may be effectively applied for the disinfection of polluted water. This process could be considered a promising method of cleaning and purification, and applicable for water disinfection.

Soil pollution by oil compounds is a serious environmental and ground water problem throughout the world. Total petroleum hydrocarbons (TPH) are a combination of many distinctive compounds. Some of these compounds in exposure with human and animal can cause cancer، disorder central nervous system، liver and lungs affects. The objective of this research was to investigate gasoline removal (C10 – C 28) using Brij 35 and Tween 80 from polluted soil. In this experimental study، the efficiency of soil washing with nonionic surfactants (Brij 35، Tween 80) for remediation of gasoline polluted soils was studied. The effects of soil washing time، agitation، surfactant concentration، and pH on the removal efficiency were studied. The results showed that gasoline removal efficiency increased with increasing agitation speed and washing time. In addition، it was found that removal efficiency of gasoline was decreased by increasing surfactant concentration. But، increasing pH did not have remarkable effect on removal efficiency of gasoline. The efficiencies of Tween 80 and Brij 35 for removal of gasoline under optimal condition were 70 -80 and 60- 65% respectively. The results showed that soil washing with non ionic surfactants was effective in removal of gasoline from polluted soil and it can be recommended for treating surface soil polluted.

Backgrounds and The base structure of total petroleum hydrocarbons (TPH) is made of hydrogen and carbon. Widespread use, improper disposal and accidental spills of this compounds lead to long term remaining of contaminations such as organic solvents and poly aromatic hydrocarbons (PAHs) in the soil and groundwater resources, resulting in critical environmental issues. In this study, an oil-contaminated soil was washed using Tween 80 surfactant and the application of photo-Fenton process (UV/Fe2+/H2O2) for treatment of the produced wastewater was evaluated. Tween 80 is a yellow liquid with high viscosity and soluble in water. In order to determine of the photo-Fenton process efficiency, we studied effective variables including Fe concentration, pH, H2O2 concentration, and irradiation time. The UV irradiation source was a medium-pressure mercury vapor lamp (400 w) vertically immersed in the solution within 2L volume glass cylindrical reactor. The results showed that efficiency of COD removal depends on the initial Fe concentration, pH, H2O2 concentration and irradiation time. Under optimum conditions, (Fe: 0.1mM, H2O2: 0.43 mM, pH: 3 and UV light irradiation time: 2 hours) the removal efficiency of COD was 67.3%. pH plays a crucial role in the photo-Fenton process such that the removal efficiency increased with decreasing of pH. According to the results of this study, under acidic condition, this process is an efficient method for COD removal from the wastewater studied.

 This study aimed to evaluate effectiveness of the coagulation process for reactive blue 19 dye (RB19) removal from textile industry wastewater. 

 In this research, coagulation process using three coagulants poly aluminum chloride (PACl), alum, and ferric chloride in the presence of anionic polyelectrolyte and kaolin as coagulants aid were studied for the removal of RB19 dye from synthetic wastewater. The influence of effective parameters such as pH, coagulant dose, initial dye concentration, and addition of coagulants aid was investigated. 

 The results showed that the best dye removal efficiency using three coagulants was archived in neutral pH. Under this condition, the optimum dose of PACl, alum, and ferric chloride was 200, 300, and 400 mg/L and corresponding to dye removal efficiency of 91%, 92%, and 81%, respectively. Addition of polyelectrolyte as a coagulant aid with ferric chloride slightly increased process efficiency, whereas adding polyelectrolyte with alum and PACl slightly decreased dye removal efficiency. By addition of kaolin as a coagulant aid with PACl increased dye removal efficiency about 5%, whereas adding kaolin with alum slightly decreased removal efficiency and can be ignored also, in the case of ferric chloride no significant effect on process efficiency observed in the presence of kaolin. 

 Regarding to obtained results, coagulation can be a robust treatment method for the management of wastewater containing reactive dye.

One of the major elements of any educational system is the student. Student satisfaction at educational services is important to increase motivation and improve education quality. The present study was conducted in order to measure students’ satisfaction of computer site performance with regard to hardware and software provision. This descriptive cross-sectional study was done using a questionnaire to collect data. Statistical population included the students studying in 2010 (n=127). The questionnaire had three sections including site physical condition, hardware, and software, and site personnel behavior. Data was analyzed by SPSS and descriptive statistics. The findings clearly showed that the students showed relative satisfaction for applied software set-up, antivirus up date and appropriate software in the site with 65.3, 63.9, and 59.8 percent cumulative agreement (strongly agree and agree) respectively. But most of the students were not agreed to quantity of computers (72.5 percent). However, in the case of computer up date and processing, satisfaction rate was approximately average. With regard to the results of this research, satisfaction of students of computer site is moderate. Therefore, it is necessary to take measures to change the present conditions by policy makers.

 The aim of the present study is to investigate the efficiency of ultraviolet/ nickel oxide (UV/NiO) system as one form of advanced oxidation processes (AOP) for decolorization of red poly azo. 

 This study was conducted as a laboratory scale in a batch mode. Ultraviolet radiation was provided by a low pressure (11 W) UV lamp. Effects of various factors including pH, different irradiation durations, different concentration of nickel oxide, and initial dye concentration were evaluated. 

 The results of the UV/NiO system's assessment showed that UV light alone cannot remove DR 80 dye. Nickel oxide is an effective catalyst in the decolorization of dye with the nanophotocatalytic process. The decolorization efficiency increases with decreasing pH value and the optimum pH value is 4. Fainally, the highest removal efficiency achieved by UV/NiO process for DR 80 dye with concentrations of 25 mg/l and 50 mg/l was 94.3% and 82.2%, respectively. UV/NiO-based decolorization process follows pseudo-second-order reaction kinetics. 

 From the findings of the present study, it can be concluded that UV/NiO process is an effective technique for decolorization of poly azo dye, DR 80, in aqueous solutions.