Background and Objectives: PHenol is one of most common organic pollutants in aqueous environments. PHenol presenCe in the environment can make some health problems such as carcinogenesis, abnormality of heartbeat, etc for humans and poisonous problems for other organisms. Therefore, this pollutant must be removed from polluted effluents to prevent water pollution. Using nanoparticles in adsorption proCesses is considered as an effective method for contaminants REMOVAL. The aim of this study was to investigate the EFFICIENCY of magnesium oxide nanoparticles in pHenol REMOVAL from aqueous solutions.Materials and Methods: In this research, nanoparticles of magnesium oxide were used with size of 43 nm. After the prEPAration of pHenol stock solution, effects of pH, (3- 5- 7- 9- 11), contact time (10, 30, 60, 90, and 120 min), MgO dosage ( 20, 40, 60, 80 and 100 mg/L) and initial conCentration of pHenol (25, 50, 75 and 100 mg/L) Were investigated.Results: Results indicated that the REMOVAL EFFICIENCY increased with increasing pH, contacttime, MgO dosage to a Certain range and decreasing initial conCentration. Such that the maximum EFFICIENCY was equal to 81% in the pH of about 11, initial conCentration of 50 mg/L, MgO dosage of 80 mg/L and contact time of 60 min. It was found that adsorption kinetics and equilibrium data follow a pseudo-second-order kinetics model and a Langmuir isotherm model respectively.Conclusion: This study showed that the magnesium oxide nanoparticles have the ability to remove the pHenol and can be used effectively in removing pHenol from aqueous solution Document Type: Research article

Background: Dye is one of the most important pollutants in textile industry wastewater and is often toxic, carcinogenic, and mutagenic. Thus, dye contaminants should be treated before discharge into the environment. This study was conducted to assess the EFFICIENCY of Glycyrrhiza glabra ash in Reactive Black 5 dye REMOVAL from aqueous solutions.Methods: The present experimental study was performed at a laboratory scale. The adsorbent was prepared under laboratory conditions and pulverized using American Society for Testing and Materials (ASTM) standard sieves. In this research, the effect of pH (2-12), initial dye concentration (20, 60, and 80 mg/l), absorbent dosage (0.3-2 gr/100 ml), and reaction time (10-180 minutes) were investigated.Findings: The results showed that the efficacy of Glycyrrhiza glabra root ash in dye REMOVAL decreased with increase in pH and initial dye concentration, and increased with increase in exposure time during the initial 60 minutes. The results followed the Langmuir isotherm (R2=0.9467).Conclusion: The results showed that licorice root ash has desirable efficacy (98.48% REMOVAL at a concentration of 20 mg of pollutant) in the REMOVAL of Reactive Black 5 dye from aqueous solutions and textile industry wastewater.

Advanced oxidation processes are associated with the production of very active hydroxyle radicals with a high potential for oxidation of organic compounds. One such process is Fenton process which reacts with ferrous ions in acidic media to produce a hydroxyle radical. It is an oxidation-reduction reaction in which the metallic ion accepts the transfer of one electron. A variety of factors such as pH, temperature, reaction time, and ferrous and H2O2 concentrations may affect the EFFICIENCY of the method. In this study, synthetic solutions of anionic LAS and ABS both having wide household and industrial applications were obtained and used to evaluate the EFFICIENCY of Fenton process in the REMOVAL and treatability of different concentrations of ferrous and H2O2 for a variety of contact times. Experiments were performed with different concentrations of H2O2 and ferrous iron at a constant pH of 3 in a jar test apparatus adjusted at 200 rpm and for different contact times (20, 40, 60, and 80 minutes). Results showed that increase in catalyst and oxidant concentrations increased REMOVAL EFFICIENCY. At a H2O2 concentration of 750 mg/l and a ferrous ion concentration of 130mg/l, 86% of LAS and ABS was removed in 80 minutes. Under these conditions, Fenton oxidation reduced the COD content of the ABS sample from 470 mg/L to 187 mg/L. The BOD5/COD ratio improved by 0.225 for a concentration of 600 mg/L of H2O2 and 130 mg/L of ferrous ion in 60 minuets. Measurements after the reaction revealed that pH reduced from 3 to 2.6 as a result of acidic intermediaries produced; this can be interesting for reaction control investigations.

Backgrounds and Aims: Ammonia REMOVAL from air to prevent severe damage to the environment and living organisms is very important. Biofiltration is an efficient, easy, cost-effective, and environmentally friendly process for degradation of ammonia from waste air. The aim of this study is to investigate the EFFICIENCY of biological filtration using a compost and scallop bed for ammonia REMOVAL.Materials and Methods: According to the ammonia REMOVAL method a column with 14cm inner diameter and 45cm height made from transparent Plexiglas was used. The column was filled up to 25 cm with compost and scallop (with a scallop: compost ratio of 1: 4).In this study, performance of the biofilter was studied under 10 different flow rates (1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 lit/min) and 5 different concentrations (0-20, 20-40, 40-60, 60-80 and 80-100 ppm) at a temperature of 25 degrees Celsius.Results: The results of this study showed that EFFICIENCY is decreased when the flow rate or concentration is increased because the microbial population is reduced. The EFFICIENCY was reduced by 84.6-98.2 percent. Maximum EFFICIENCY occurred at a 0.19g/ (m3.h) loading rate. EFFICIENCY was in 0-20 concentration intervals at a flow rate of 1 lit/min and at an Empty Bed Residence Time (EBRT) of 240 seconds.Conclusion: The results show that a biofilter with a compost and scallop bed is efficient for ammonia REMOVAL from air. Results can be optimized in the design and operation of biological systems to be used in the industrial control of ammonia gas.

Background: An excessive level of heavy metals is one of the most common environmental pollutants that damage human health. Electrocoagulation (EC) is an electrochemical technique with different applications that has been used for lead REMOVAL from wastewater.Objective: The aim of this study was to determine EFFICIENCY of electrocoagulation process for lead REMOVAL from wastewater.Methods: This laboratory study was performed in School of Public Health affiliated to Qazvin University of Medical Sciences during 2013. A laboratory batch electrocoagulation reactor was designed and constructed from Perspex with dimensions of 17 cm* 12 cm* 40 cm and was applied for coagulation and flotation. The aluminium electrodes were connected in a bipolar configuration. Electrolysis was performed for 30 min in each run. Samples were taken every 5 minutes and parameters such as current density, electrolysis time, pH and different concentrations of lead were measured. The lead concentration was 5, 10 and 15 mg/l, and the pH was ranged from 5 to 9.Findings: The REMOVAL EFFICIENCY was found to be dependent on the pH, initial concentration, current density, and electrolysis time. The REMOVAL EFFICIENCY was decreased with increased initial concentration while it was increased with increase in electrolysis time and current density. The REMOVAL EFFICIENCY of 94% was achieved for the current density of 33 A/m2, pH of 7, and electrolysis time of 30 min, respectively.Conclusion: With regards to the results, the electrocoagulation process is an effective method for lead REMOVAL from wastewater.

Background and purpose: So far, different methods have been used to remove residual antibiotics from aquatic environments. This study investigated the EFFICIENCY of enzyme horseradish peroxidase (HRP) in presence of hydrogen peroxide in REMOVAL of Tetracycline and Ciprofloxacin in a batch system. Materials and methods: In an experimental study on laboratory scale, the effects of contact time, concentrations of H2O2, the antibiotics, and enzyme, and reaction pH on the performance of pure HRP enzyme in the presence of H2O2, were investigated. To measure the EFFICIENCY of the enzymatic process, the residual antibiotics were measured using HPLC equipped with a reverse phase column (C-18, 5% micrometer, 250 * 4. 6 mm). The flow rate was 1 ml/min and the injection volume was 40 μ l. The mobile phase of Tetracycline was 0. 1 M TFA-methanol (60: 40) used at 254 nm and the mobile phase of ciprofloxacin was 0. 01 M acetonitrile-phosphate (8: 92) at 220 nm. All experiments were performed in a discontinuous system at laboratory temperature. Results: REMOVAL efficiencies of Tetracycline and Ciprofloxacin were 40% and 95%, respectively, at 10 mg/l initial concentrations of antibiotics, 10-min contact time, Tetracycline pH= 4, and Ciprofloxacin pH= 7. The REMOVAL EFFICIENCY of Ciprofloxacin was two times more than that of Tetracycline. Conclusion: The free HRP could be used as an effective process in removing Tetracycline and Ciprofloxacin from wastewater.

Antibiotics are potential pollutants that represent an important environmental problem because of their toxic effects on the food chain and aqueous streams. The goal of this study was determining the EFFICIENCY of a horizontal subsurface flow constructed wetland for a pharmaceutical pollutants antibiotic penicillin G. This study used constructed wetland pilot system for REMOVAL of penicillin G in artificial wastewater. in this study, the effects of initial concentration of wastewater, hydraulic retention time and reed on the pollutant REMOVAL EFFICIENCY were investigated. The data was analyzed using the central composite design which is the most commonly used response surface methodology design. 30 Samples of wastewater were taken from the output of constructed wetlands subsurface and tested in laboratory based on the standard reference method for experiments in water and wastewater. The results showed that reed, and retention time, has a direct relationship, and enhance them to increase EFFICIENCY. The initial concentration of wastewater is inversely related to REMOVAL EFFICIENCY. In the constructed wetland, the REMOVAL EFFICIENCY for 72 hours and different input concentrations was between 94. 17% and 73. 61%. Based on the study results, it can be stated that subsurface constructed wetland can remove the maximum concentration of hospital wastewater and even double this concentration with EFFICIENCY up to 90 percent, and it can be used as a proper treatment system for REMOVAL of penicillin G.