Hexavalent chromium removal by using synthesis of polyaniline and polyvinyl alcohol

2016 ◽  
Vol 74 (10) ◽  
pp. 2305-2313 ◽  
Author(s):  
Majid Riahi Samani ◽  
Parisa Ebrahimbabaie ◽  
Hamed Vafaei Molamahmood
Keyword(s):  
Heavy Metals ◽  
Polyvinyl Alcohol ◽  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Chromium Concentration ◽  
Chromium Removal ◽  
Chromium Vi ◽  
Pani Composite ◽  
Stirring Time ◽  
Textile Finishing

Over the past few years, heavy metals have been proved to be one of the most important contaminants in industrial wastewater. Chromium is one of these heavy metals, which is being utilized in several industries such as textile, finishing and leather industries. Since hexavalent chromium is highly toxic to human health, removal of it from the wastewater is essential for human safety. One of the techniques for removing chromium (VI) is the use of different adsorbents such as polyaniline. In this study, composites of polyaniline (PANi) were synthesized with various amounts of polyvinyl alcohol (PVA). The results showed that PANi/PVA removed around 76% of chromium at a pH of 6.5; the PVA has altered the morphology of the composites and increased the removal efficiency. Additionally, synthesis of 20 mg/L of PVA by PANi composite showed the best removal efficiency, and the optimal stirring time was calculated as 30 minutes. Moreover, the chromium removal efficiency was increased by decreasing the pH, initial chromium concentration and increasing stirring time.

scholarly journals Chromium removal from tannery effluents by adsorption process via activated carbon chat stems (Catha edulis) using response surface methodology

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yigezu Mekonnen Bayisa ◽  
Tafere Aga Bullo ◽  
Desalegn Abdissa Akuma
Keyword(s):  
Heavy Metals ◽  
Activated Carbon ◽  
Removal Efficiency ◽  
Cost Effective ◽  
Treatment Method ◽  
Proximate Analysis ◽  
Chromium Removal ◽  
Tannery Effluents ◽  
Chromium Vi ◽  
Before And After

Abstract Objective In tannery processing, water consumption is high, which generates wastewater as a by-product and numerous pollutants such as chromium heavy metals that make adverse effects of water bodies and the surrounding environment. This study analyzed, chromium (VI) removal from wastewater through activated carbon chat stem was investigated. Adsorption is a common treatment method via activated carbon due to its cost-effective, profitable, and removal efficiency of these heavy metals. Results The proximate analysis of moisture content of chat stem has 6%, activated carbon ash content of 17.35%, volatile materials of 20.12%, and fixed carbon contents of 56.53%, which are well-matched the standards quality of activated carbon. As the process parameter varies, the increment of the chromium removal efficiency was from 62.5 to 97.03%. The maximum adsorption efficiency was observed at 30 g/L dosage of the adsorbent, at pH 4, and contact time at 180 min of activated carbon from chat stem waste was found 97.03%. FTIR was used to characterize the surface of the chat stem before and after adsorption. Langmuir and Freundlich are used for short contact time’s adsorption isotherm 0.9839 and 0.9995 respectively, which conformed, no visible change in the corrosion state.

scholarly journals Positive effects of concomitant heavy metals and their reduzates on hexavalent chromium removal in microbial fuel cells

RSC Advances ◽  
2020 ◽  
Vol 10 (26) ◽  
pp. 15107-15115 ◽  
Author(s):  
Xiayuan Wu ◽  
Chunrui Li ◽  
Zuopeng Lv ◽  
Xiaowei Zhou ◽  
Zixuan Chen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Fuel Cells ◽  
Hexavalent Chromium ◽  
Microbial Fuel Cells ◽  
Chromium Removal ◽  
Positive Effects ◽  
Bioelectricity Generation ◽  
Co Reduction

The cooperative cathode modification by BioAu from Au(iii) and in situ Cu(ii) co-reduction enhanced Cr(vi) removal and bioelectricity generation in MFCs.

scholarly journals Removal of Nitrate and Hexavalent Chromium from Groundwater Using Zerovalent Iron – A Laboratory Study

2010 ◽  
Vol 67 (2) ◽  
Author(s):  
Cristina MODROGAN ◽  
Alexandra MIRON ◽  
Oanamari ORBULET ◽  
Cristina COSTACHE
Keyword(s):  
Heavy Metals ◽  
Groundwater Contamination ◽  
Human Health ◽  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Laboratory Study ◽  
Nitrate Reduction ◽  
Laboratory Experiments ◽  
Zerovalent Iron ◽  
Inorganic Pollutants

. Groundwater contamination by inorganic pollutants such as heavy metals, chromium and nitrate has recently begun to attract widespread interests because of significant threat to human health. Nitrate and chromate are most frequently detected contaminants in groundwater. In this paper, we describe a series of laboratory experiments which quantify the rate of chromium (Cr6+) and nitrate reduction by Fe0. The main goal of these experiments was to determine the removal efficiency of chromium (Cr6+) and nitrate ions using iron. The results indicate that in the presence of zero valence iron Cr6+ reduces to Cr3+, and NO3- to NH4+.

scholarly journals Electrocoagulation Based Chromium Removal Efficiency Classification Using Logistic Regression

2020 ◽  
Vol 10 (15) ◽  
pp. 5179
Author(s):  
Meryem Akoulih ◽  
Smail Tigani ◽  
Rachid Saadane ◽  
Amal Tazi
Keyword(s):  
Heavy Metals ◽  
Logistic Regression ◽  
Removal Efficiency ◽  
Chromium Removal ◽  
Refractory Alloys ◽  
Best Value ◽  
Proposed Model ◽  
Auc Value ◽  
Special Steels ◽  
Minimal Area

Surface treatment and tanning industries use huge quantities of heavy metals—especially Chromium (III) and (VI)—in their processes thanks to its physical proprieties. It is used in the composition of special steels and refractory alloys. By dint of using this metal, an enormous quantity of rejects is produced each year and discharged into the oceans. As this is very dangerous for our environment, it is very important to treat these discharges before getting rid of them. This study treats chromium removal as a special type of heavy metals that can be a component of industrial discharges. Electrocoagulation is considered among the best methods used in this kind of treatment. However, it requires a lot of time, energy and remains expensive. This paper presents a predictive model in order to classify the chromium removal efficiency using electrocoagulation method. The proposed model is a logistic regression (LR) that consumes four parameters that we call predictors: pH, time, current, and stirring speed. After the training and validation process, we obtained 88% as classification precision, recall and F-Score metrics values while the use of the 10-Folds cross-validation method gave a minimal area under curve (AUC) value of 97% while the best value attempts 100%. Classification report states that the model performs well comparing to similar experimentation efficiencies.

Removal of Hexavalent Chromium and Turbidity in Drinking Water by Chitosan

2012 ◽  
Vol 433-440 ◽  
pp. 793-797 ◽  
Author(s):  
Shao Xiu Li ◽  
Yu Qiang Lian ◽  
Jian Feng Mai ◽  
Jian Xiong Tan ◽  
Shu Jie Hu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Drinking Water ◽  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Metal Ion ◽  
Removal Rate ◽  
Turbidity Removal ◽  
Initial Concentration ◽  
Stirring Time ◽  
Slow Mixing

The threat of heavy metal pollution in water sources becomes increasingly serious. Toxic hexavalent chromium is harmful for health. Chitosan is a non-toxic and pollution-free substance, it is a cationic coagulant after protonated in diluted acid solution, it also can complex for many heavy metal ion. The study on removal of Cr (Ⅵ) and turbidity in drinking water by chitosan in this paper was performed. The results showed that the removal efficiency of Cr (Ⅵ) decreased with increasing pH, the removal rate of Cr (Ⅵ) was as high as 100% at pH4 using the chitosan concentration of 1.0g/L, but in these conditions, the turbidity was not removed. The removal efficiency of Cr (Ⅵ) bore relationship to stirring time of slow mixing step and initial concentration of Cr (Ⅵ). The best stirring time was 4 hours. To attain a good removal efficiency of Cr (Ⅵ), the dosage of chitosan must increase with the initial concentration of Cr (Ⅵ) increasing. At pH7, low chitosan dosage had good turbidity removal.

scholarly journals The Use of Tea leaves Wastes to reduce Hexavalent Chromium Concentration in industrial Waste Water by Adsorption

2014 ◽  
Vol 11 (2) ◽  
pp. 1067-1073
Author(s):  
Baghdad Science Journal
Keyword(s):  
Waste Water ◽  
Hexavalent Chromium ◽  
Chromium Concentration ◽  
Experimental Results ◽  
Isotherm Models ◽  
Freundlich Model ◽  
Adsorption Isotherm Models ◽  
Freundlich Adsorption Isotherm ◽  
Stirring Time ◽  
Carcinogenic Compound

Abstract : A research was conducted to study the process parameters affecting hexavalent chromium Cr (VI) (carcinogenic compound) the removal percentage from the electrical industries company waste water that contain 88 mg/l of Cr (VI) concentration by adsorption onto tea wastes. Synthetic water with 88 mg/l Cr (VI) concentration was used. Several operation parameters affecting Cr (VI) removal efficiency were investigated, such as pH, initial Cr (VI) concentration, stirring time and tea wastes dose. The experimental results reveal that maximum Cr (VI) removal reached up to 94.26% at pH of 2, stirring time of 180 minute, tea wastes dose of 8gm/100 ml and the equilibrium was attained at 180 minute. Langmuir and Freundlich adsorption isotherm models were analyzed and the experimental results fit very well with Freundlich model.

scholarly journals Investigating the hexavalent chromium removal from aqueous solution applying bee carcasses and corpses modified with Polyaniline

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Ali Hosseini ◽  
Majid Riahi Samani ◽  
Davood Toghraie
Keyword(s):  
Heavy Metals ◽  
Polyethylene Glycol ◽  
Hexavalent Chromium ◽  
Adsorption Isotherms ◽  
Contact Time ◽  
Environmental Pollutants ◽  
Industrial Effluents ◽  
Xrd Analysis ◽  
Chromium Concentration ◽  
Polyethylene Composite

AbstractThere are currently heavy metals in most industrial effluents which are among the most significant environmental pollutants. Hexavalent chromium is one of the most significant heavy metals. In this research for the first time, eliminating the hexavalent chromium from the aqueous medium/aquedia applying bee carcasses and corpses modified with polyethylene was examined. Adsorption experiments were conducted discontinuously on laboratory solutions, including hexavalent chromium. The optimal adsorption conditions such as different pH factors, contact time, initial chromium concentration, and adsorbent value on the adsorption rate were examined at different levels, and adsorption isotherms were plotted. Some adsorbent properties were examined using Field Emission Scanning Electron Microscopy, XRD analysis, Fourier Transform Infrared Spectroscopy, and BET test to study the properties of the synthesized adsorbent. This study indicated that the highest percentage of removal related to polyethylene composite and bee carcasses in the presence of polyethylene glycol was 50.56% among the bee carcasses composites. The parameters effective on the adsorption process for polyethylene composite and bee carcasses and losses in the presence of polyethylene glycol suggested that the adsorption percentage increased for this composite by decreasing the pH, increasing the contact time, and increasing the adsorbent. The highest percentage of adsorption was obtained when the pH was 2, the contact time was 120 min and the adsorbent value was 8 g/L and the initial concentration of chromium was 100 ppm. The most optimal removal percentage was achieved at the pH = 2, the contact time was 30 min, and the adsorbent value was 2 g/L, and the initial chromium concentration was 100 ppm. The results of drawing adsorption isotherms also indicated that higher R2 had a better fit than Langmuir for polyethylene composite and bee carcasses in the polyethylene glycol Freundlich equation.

Breakthrough analysis for hexavalent chromium removal from drinking water in a fixed bed column

2009 ◽  
Vol 9 (6) ◽  
pp. 661-670 ◽  
Author(s):  
S. P. Dubey ◽  
K. Gopal
Keyword(s):  
Aqueous Solution ◽  
Hexavalent Chromium ◽  
Fixed Bed ◽  
Entropy Change ◽  
Spectroscopic Technique ◽  
Fixed Bed Column ◽  
Chromium Vi ◽  
Fixed Bed Adsorption ◽  
Optimal Column ◽  
Eucalyptus Bark

The activated carbon of Eucalyptus globulus was tested for their effectiveness in removing hexavalent chromium from aqueous solution using column experiments. Result revealed that adsorption of chromium(VI) on eucalyptus bark carbon was endothermic in nature. Thermodynamic parameters such as the entropy change, enthalpy change and Gibbs free energy change were found to be 1.39 kJ mol−1 K−1, 1.08 kJ mol−1 and −3.85 kJ mol−1, respectively. Different chromium concentrations were used for the fixed bed adsorption studies. The pre- and post-treated adsorbents were characterized using a FTIR spectroscopic technique. It was concluded that Eucalyptus bark carbon column could be used effectively for removal of hexavalent chromium from aqueous solution at optimal column conditions. This study showed that this biological material is potential adsorbent of Cr(VI) from water.

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