An Investigation of the Efficacy of Cuttlefish Bone Powder in the Removal of Reactive Blue 19 Dye from Aqueous Solutions: Equilibrium and Isotherm Studies

Introduction: Discharge of textile wastewater causes the reduction of sunlight penetration, interferes with the receiving waters ecology and damage the environment. The aim of this study was to determine the removal efficiency of reactive blue 19 dye from aqueous solutions by cuttlefish bone powder. Materials & Methods: This study was performed experimentally and in laboratory scale. In this research, the effect of adsorbent dose, contact time, initial dye concentration and pH was evaluated. Dye concentration in unknown samples was determined by UV/Vis spectrophotometer. In order to better understand the adsorption process, the experimental data were analysed with Langmuir and Freundlich isotherm models. Results: Results showed that increasing the adsorbent dose up to 0.4 gr/100ml and increasing of contact time, led to an increase in the efficiency of dye removal. Increasing the initial pH had no effect on the adsorption efficiency and increasing the initial concentration of dye decreased the removal efficiency. The Removal efficacy of the dye was found to be 60%, 45%, 37.5% and 31.9% at the time interval of 3h and the initial dye concentrations of 25, 50, 75 and 100 mg/l, respectively. The experimental data were in good concordance with Langmuir isotherm model (R2=0.993). Conclusion: Cuttlefish bone powder is a natural and inexpensive adsorbent that can be used for the removal of environmental contaminations. The adsorption process is affected by sorbent dose, initial dye concentration and contact time but pH had no significant effect on removal efficienc

Evaluation of Maize Tassel Powder Efficiency in Removal of Reactive Red 198 Dye from Synthetic Textile Wastewater

Introduction: Colored compounds which often are toxic and carcinogen is one of the environmental pollutants. These pollutants should be removed prior than discharge to the environment. The aim of this study was the evaluation of maize tassel powder efficiency for the removal of Reactive Red 198 dye from synthetic textile wastewater. Materials & Methods: This experimental study was performed in laboratory scale by using of batch reactors. In this study, the effect of adsorbent dose, contact time, initial dye concentration and pH had been evaluated. Maximum adsorption wavelength (λmax) and the concentration of dye were determined by UV/Vis spectrophotometer. The adsorbent was prepared in laboratory condition and pulverized by standard ASTM sieves with the range of 40-60 mesh. The data were analyzed with Langmuir and Freundlich isotherm models. Results: The result showed that increasing of adsorbent dose led to increasing of the adsorption efficiency but adsorption efficiency was decreased with an elevation of pH from 3 to 9 and increasing of dye concentration from 25 to 50 mg/l. With increasing reaction time, adsorption efficiency increased and the most adsorption occurred in first 30 min of reaction. Obtained data were in good concordance with both Langmuir and Freundlich isotherm models. The adsorption kinetics followed the pseudo-second-order equation. Conclusion: Maize tassel powder is a natural and cheap adsorbent that can be used for the removal of contaminants in the environment

Adsorption of humic acid from aqueous solutions onto shellfish ash: Kinetic and isotherm studies and artificial neural network modeling

Background: Natural organic matters such as humic acid react with chlorine and produce disinfection by products such as trihalomethanes that are carcinogenic. In this study, shellfish ash was used as a novel adsorbent for removal of humic acid. Methods: The present study was performed under various laboratory conditions including pH, adsorbent dose, contact time, and initial concentration of humic acid. Residual concentrations of humic acid in the samples were determined by a UV-Vis spectrophotometer at 254 nm wavelength. Artificial neural network (ANN) modeling studies were also performed. Results: Elemental analysis showed that the shellfish ash was 98% pure calcium. It was indicated that the maximum adsorption capacity was achieved in acidic conditions (pH = 3) and pHzpc was found to be 10.3. The adsorption data followed the Langmuir model (R2 > 0.9). The adsorption of humic acid followed the pseudo-second-order kinetic (R2 = 0.999). ANN modeling also provided the accurate prediction of humic acid adsorption for testing data (R2 = 0.989). Conclusion: According to the results, shellfish ash is recommended as an effective biosorbent for removal of organic pollutants such as humic acid. Keywords: Adsorption, Humic substances, Kinetics, Shellfish, Neural networ

Knowledge, Attitude and Practice of Women Regarding Health Hazards and Proper Methods of Storage and Use of Pesticides at Home in Abarkouh

Introduction: A large amount of pesticides is used worldwide in different locations including homes. Considering that using pesticides in the home is mainly done by women, this study was conducted to determine the knowledge, attitudes and practices of women regarding health hazards and proper methods of storage and use of pesticides in the home in Abarkouh. Materials and Methods: In this descriptive study, data were collected using cluster sampling and questionnaire by interviewing 210 eligible women in households. The questionnaire was included demographic information (age, education level, field of study, occupation, type of home), as well as knowledge, attitudes and practices of women. Validity and reliability of the questionnaire have been confirmed in previous studies. Data were analyzed by SPSS using nonparametric tests. Results: According to results, the mean score of attitude among different academic disciplines was statistically significantly (p = 0.049). In addition, there was a significant relationship between attitude score with practice (p = 0.003) and knowledge (p < 0.0001) scores. Conclusion:&nbsp;Considering the fact that people's knowledge about this subject was moderate, their knowledge should be increased to make their attitude and practice more desirable