scholarly journals Electrocoagulation as an Alternative for the Removal of Chromium (VI) in Solution

Tecnura ◽  
2021 ◽  
Vol 25 (68) ◽  
pp. 28-42
Author(s):  
Candelaria nahir Tejada tovar ◽  
Angel Villabona Ortíz ◽  
Rafael Contreras Amaya

Context: The contamination of water sources by the discharge of effluents contaminated with chromium (VI) is a current environmental problem because it is a toxic pollutant for humans, animals, plants, and microorganisms; it can be carcinogenic and has a high solubility in an aqueous environment. This research aims to study the electrochemical removal of hexavalent chromium by electrocoagulation using iron and aluminum electrodes with monopolar configuration, evaluating the effect of residence time, voltage, and the number of electrodes on the removal efficiency. Methodology: The experiments were conducted in a 3L batch electrocoagulation cell, using 10 and 6 aluminum and stainless steel plates as electrodes, connected at a distance of 1.5 cm in a monopolar configuration in parallel to the power source. Contaminated solution with Cr (VI) was treated at a concentration of 50 mg/L, evaluating two levels of residence time (20 and 30 min), voltage (20 and 30 V), and the number of electrodes (6 and 10 electrodes). Results: After the electrocoagulation removal tests, it was obtained removal percentages between 60.15 and 92.9%. The most significant positive variable in the process was the increase in the residence time. It can be inferred that electrocoagulation performs better at lower voltages and longer residence times and that the joint effect of the increase of the number of electrodes and the contact time would increase the performance of the process, achieving greater removal. Conclusions: The process of reduction of chromium (VI) by electrocoagulation has the potential to be used for the cost-effective removal of heavy metals from water

Author(s):  
Davoud Balarak ◽  
Kethineni Chandrika ◽  
Marzieh Attaolahi

In this study, efficiency of electrocoagulation (EC) process with aluminum electrodes for treatment of Amoxicillin (AMO) from synthetic solution has been studied and concluded. This experiment was conducted in a batch system with a volume of 1 L that had been equipped with four aluminum electrodes. The effect of operating parameters, such as voltage, time of reaction, initial AMO concentration, KCl concentration and pH on the AMO removal efficiency was investigated. In optimum condition (pH 7, voltage 60 V, electrolysis time 75 min, KCl concentration 3 g/L), electrocoagulation method was able to remove 98.8% of AMO antibiotics from synthetic solution.  In addition, it is found that an increase in the applied voltage the speed of the treatment significantly. However, simultaneous increase of electrode and energy consumption was observed. The method was found to be highly efficient and relatively fast compared to conventional existing techniques and also, it can be concluded that the electrocoagulation process has the potential to be utilized for the cost-effective removal of AMO from water and wastewater.


2012 ◽  
Vol 9 (4) ◽  
pp. 2297-2308 ◽  
Author(s):  
Edris Bazrafshan ◽  
Kamal Aldin Ownagh ◽  
Amir Hossein Mahvi

Fluoride in drinking water above permissible level is responsible for human being affected by skeletal fluorosis. The present study was carried out to assess the ability of electrocoagulation process with iron and aluminum electrodes in order to removal of fluoride from aqueous solutions. Several working parameters, such as fluoride concentration, pH, applied voltage and reaction time were studied to achieve a higher removal capacity. Variable concentrations (1, 5 and 10 mg L-1) of fluoride solutions were prepared by mixing proper amount of sodium fluoride with deionized water. The varying pH of the initial solution (3, 7 and 10) was also studied to measure their effects on the fluoride removal efficiency. Results obtained with synthetic solution revealed that the most effective removal capacities of fluoride could be achieved at 40 V electrical potential. In addition, the increase of electrical potential, in the range of 10-40 V, enhanced the treatment rate. Also comparison of fluoride removal efficiency showed that removal efficiency is similar with iron and aluminum electrodes. Finally it can be concluded that the electrocoagulation process has the potential to be utilized for the cost-effective removal of fluoride from water and wastewater.


2017 ◽  
Vol 17 (01n02) ◽  
pp. 1760013 ◽  
Author(s):  
J. Baalamurugan ◽  
V. Ganesh Kumar ◽  
K. Govindaraju ◽  
B. S. Naveen Prasad ◽  
V. K. Bupesh Raja ◽  
...  

Slag-based nanomaterial is a by-product obtained during steel production and has wide range of components in the form of oxides. In this study, Induction Furnace (IF) steel slag-based application in adsorption of hexavalent chromium is investigated. IF slag has mixture of oxides mainly Fe2O3 and Chromium (VI) a highly toxic pollutant leads to environmental pollution and causes problem to human health mainly, carcinogenetic diseases. Slag-based nanomaterial is characterized using High Resolution Scanning Electron Microscope (HR-SEM) in which the size was around 100[Formula: see text]nm and X-ray Fluorescence (XRF) spectroscopy. Further inductively coupled plasma mass spectroscopy and Fourier transform infrared spectroscopy were used for adsorption studies. Slag activation using NaOH (alkali activation) to the intent of surface hydroxyl ([Formula: see text]OH) group attachment will be a cost-effective process in the removal of hexavalent chromium. Cr(VI) ions are adsorbed on the surface of alkali activated slag material. The core-shell formation of Fe(II)/Fe(III)/Cr(VI) and the adsorption are investigated in detail in the present study.


2021 ◽  
Vol 897 (1) ◽  
pp. 012020
Author(s):  
Tanya Medina-Espinosa ◽  
Christopher Asimbaya ◽  
Salomé Galeas ◽  
Nelly M. Rosas-Laverde ◽  
Alexis Debut ◽  
...  

Abstract The removal of heavy metals from water is one of the major challenges that humanity must address to avoid negative potential impacts on the environment and human health. During the last few years, several adsorbents have been examined, in a search for highly efficient and cost-effective materials. In this work, we investigated the use of laurel, canelo and eucalyptus lignocellulosic sawdust residues (LRs) impregnated with magnetite nanoparticles (MNP), to remove Cr6+ ions. Each LR was added to an aqueous solution in which MNP were being synthesized by coprecipitation. Two composite adsorbents were obtained, with LR:MNP ratios of 1:1 and 3:1. The materials obtained were characterized by X-ray diffraction, scanning and transmission electron microscopy, and infrared and Raman spectroscopy. The results obtained showed that the laurel composite was the best adsorbent, reaching a maximum removal efficiency and capacity of 99.8 % and 30.5 mg/g, respectively. The optimal contact time was 30 min and the process fitted the Langmuir isotherm model, showing small effects of the fraction of sawdust residues used to support the MNP. Further studies will be performed to optimize the composition of the composites aiming to reduce the amount of costly MNP used while ensuring a high removal performance.


Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 863
Author(s):  
Romain Lemaire ◽  
Magnus Christensson

When a wastewater treatment plant (WWTP) uses anaerobic digestion (AD) on its sludge treatment line, the opportunity to install a sidestream deammonification process for the cost-effective removal of the N-rich reject water load generated by the sludge digester should be considered. In this context, the ANITA™ Mox process based on the moving bed biofilm reactor (MBBR) technology has been implemented at more than 30 full-scale facilities over the last 10 years to treat reject water from conventional AD or after thermal hydrolysis process (THP) to reduce the N-load and associated treatment costs on the WWTP. This paper reviews the lessons learned in the implementation of the ANITA™ Mox process at several WWTP in the US, Europe, and Australia.


Author(s):  
James F. Mancuso

IBM PC compatible computers are widely used in microscopy for applications ranging from control to image acquisition and analysis. The choice of IBM-PC based systems over competing computer platforms can be based on technical merit alone or on a number of factors relating to economics, availability of peripherals, management dictum, or simple personal preference.IBM-PC got a strong “head start” by first dominating clerical, document processing and financial applications. The use of these computers spilled into the laboratory where the DOS based IBM-PC replaced mini-computers. Compared to minicomputer, the PC provided a more for cost-effective platform for applications in numerical analysis, engineering and design, instrument control, image acquisition and image processing. In addition, the sitewide use of a common PC platform could reduce the cost of training and support services relative to cases where many different computer platforms were used. This could be especially true for the microscopists who must use computers in both the laboratory and the office.


Phlebologie ◽  
2007 ◽  
Vol 36 (06) ◽  
pp. 309-312 ◽  
Author(s):  
T. Schulz ◽  
M. Jünger ◽  
M. Hahn

Summary Objective: The goal of the study was to assess the effectiveness and patient tolerability of single-session, sonographically guided, transcatheter foam sclerotherapy and to evaluate its economic impact. Patients, methods: We treated 20 patients with a total of 22 varicoses of the great saphenous vein (GSV) in Hach stage III-IV, clinical stage C2-C5 and a mean GSV diameter of 9 mm (range: 7 to 13 mm). We used 10 ml 3% Aethoxysklerol®. Additional varicoses of the auxiliary veins of the GSV were sclerosed immediately afterwards. Results: The occlusion rate in the treated GSVs was 100% one week after therapy as demonstrated with duplex sonography. The cost of the procedure was 207.91 E including follow-up visit, with an average loss of working time of 0.6 days. After one year one patient showed clinical signs of recurrent varicosis in the GSV; duplex sonography showed reflux in the region of the saphenofemoral junction in a total of seven patients (32% of the treated GSVs). Conclusion: Transcatheter foam sclerotherapy of the GSV is a cost-effective, safe method of treating varicoses of GSV and broadens the spectrum of therapeutic options. Relapses can be re-treated inexpensively with sclerotherapy.


2019 ◽  
Vol 2 (4) ◽  
pp. 260-266
Author(s):  
Haru Purnomo Ipung ◽  
Amin Soetomo

This research proposed a model to assist the design of the associated data architecture and data analytic to support talent forecast in the current accelerating changes in economy, industry and business change due to the accelerating pace of technological change. The emerging and re-emerging economy model were available, such as Industrial revolution 4.0, platform economy, sharing economy and token economy. Those were driven by new business model and technology innovation. An increase capability of technology to automate more jobs will cause a shift in talent pool and workforce. New business model emerge as the availabilityand the cost effective emerging technology, and as a result of emerging or re-emerging economic models. Both, new business model and technology innovation, create new jobs and works that have not been existed decades ago. The future workers will be faced by jobs that may not exist today. A dynamics model of inter-correlation of economy, industry, business model and talent forecast were proposed. A collection of literature review were conducted to initially validate the model.


The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.


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