Lead Oxide-Graphite Composite Electrode for pH Measurement

Lead oxide-graphite composite electrode for pH measurement had been fabricated with different percentage of PbO2 in the composite. The proportions of lead oxide affected the sensitivity of the electrode. The electrode composed of 50% lead oxide and 50% graphite gave reproducible result and behaved in Nernstian manner with a potential gradient of -58.8±0.3 mV per unit change in pH. Metal ions such as iron (II), iron (III) and lead (II) interfered in the measurement of pH, while silver (I), copper (II), oxidizing agents such as dichromate and permanganate do not interfere. In absence of interfering ion, the lead oxide-graphite composite electrode could be used for the measurement of pH from 2 to 11. This electrode can also be used as an indicator electrode for acid base titrations. Low cost, quick response, easy to fabricate are some of the advantages of the lead oxide-graphite composite electrode. This electrode is also found to be sensitive to Pb2+ -ions and can be used as a Pb2+-ion sensor up to 10-4M.DOI: http://dx.doi.org/10.3126/njst.v15i1.12015 Nepal Journal of Science and TechnologyVol. 15, No.1 (2014) 61-66

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A SOLID Fe2O3-GRAPHITE COMPOSITE ELECTRODE FOR pH MEASUREMENT

Scientific World ◽

10.3126/sw.v12i12.13596 ◽

2015 ◽

Vol 12 (12) ◽

pp. 44-47

Author(s):

Suchi Srivastava ◽

Raja Ram Pradhananga

Keyword(s):

Electrode Potential ◽

Composite Electrode ◽

Low Cost ◽

Ph Sensor ◽

Potential Gradient ◽

Graphite Composite ◽

Ph Response ◽

Potentiometric Response ◽

Unit Change ◽

Oxidized Graphite

A solid Fe2O3-graphite composite electrode was prepared and investigated for use as a potentiometric pH sensor. The electrode was constructed by mixing iron (III) oxide, oxidized graphite and wax that was put over silver disc onto a polypropylene rod. The response of the electrode was investigated by measuring electrode potential as a function of pH.The effect of composition of the electrode material (Fe2O3 and oxidized graphite ration) on the electrode response was investigated. The electrode with 40% Fe2O3, 30% graphite and 30% wax by mass was found to give the best potentiometric response. This electrode behaves in Nernstian manner with a potentiometric gradient of 56.6±0.4 mV per unit change in pH at 25?C within the working range of pH 2-9.The electrode was also used for the end-point detection in potentiometric acid-base titrations and found to be an excellent electrode for pH-metric titration. The effect of oxidation of electrode on pH response was investigated by dipping electrode in 0.1N KMnO4, 1:1HNO3 and 0.1N Ce4+ solutions for different interval of time. This treatment of the electrode with oxidizing agents increased the standard electrode potential of the electrode however potential gradient per unit change in pH remains unaltered. Low cost, quick response and easy to prepare are the advantages of the iron oxide - graphite composite electrode as a pH sensor. However some metal ions and oxidising agents interfered in the determination of pH using this electrode which is the limitation of using these electrodes.Scientific World, Vol. 12, No. 12, September 2014, page 44-47

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Low cost stretchable carbon graphite composite electrode

Journal of Korean Society for Imaging Science & Technology ◽

10.14226/ksist.2020.26.04.5 ◽

2020 ◽

Vol 26 (4) ◽

pp. 126-132

Author(s):

Su-Yong Nam ◽

Shinyoung Kim ◽

Se-Hoon Park ◽

Hyun Jin Nam

Keyword(s):

Composite Electrode ◽

Low Cost ◽

Graphite Composite

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Donnan Membrane Process for the Selective Recovery and Removal of Target Metal Ions—A Mini Review

Membranes ◽

10.3390/membranes11050358 ◽

2021 ◽

Vol 11 (5) ◽

pp. 358

Author(s):

Dennis Asante-Sackey ◽

Sudesh Rathilal ◽

Emmanuel Kweinor Tetteh ◽

Elorm Obotey Ezugbe ◽

Lingham V. Pillay

Keyword(s):

Wastewater Treatment ◽

Metal Ions ◽

Large Scale ◽

Wastewater Treatment Plants ◽

Low Cost ◽

Potential Gradient ◽

External Energy ◽

Membrane Technologies ◽

Exchange Membrane ◽

Pressure Driven

Membrane-based water purification technologies contribute significantly to water settings, where it is imperative to use low-cost energy sources to make the process economically and technically competitive for large-scale applications. Donnan membrane processes (DMPs) are driven by a potential gradient across an ion exchange membrane and have an advantage over fouling in conventional pressure driven membrane technologies, which are gaining attention. DMP is a removal, recovery and recycling technology that is commonly used for separation, purification and the concentrating of metals in different water and waste streams. In this study, the principle and application of DMP for sustainable wastewater treatment and prospects of chemical remediation are reviewed and discussed. In addition, the separation of dissolved metal ions in wastewater settings without the use of pressure driven gradients or external energy supply membrane technologies is highlighted. Furthermore, DMP distinctive configurations and operational factors are explored and the prospects of integrating them into the wastewater treatment plants are recommended.

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Comparison of the fixation of several metal ions onto a low-cost biopolymer

Water Science & Technology Water Supply ◽

10.2166/ws.2002.0172 ◽

2002 ◽

Vol 2 (5-6) ◽

pp. 217-224 ◽

Cited By ~ 6

Author(s):

Z. Reddad ◽

C. Gérente ◽

Y. Andrès ◽

P. Le Cloirec

Keyword(s):

Aqueous Solutions ◽

Metal Ions ◽

Low Cost ◽

Operating Conditions ◽

Order Kinetic ◽

Adsorption Mechanisms ◽

Equilibrium Data ◽

Order Kinetic Model ◽

Beet Pulp ◽

Removal Of Metal Ions

In the present work, sugar beet pulp, a common waste from the sugar refining industry, was studied in the removal of metal ions from aqueous solutions. The ability of this cheap biopolymer to sorb several metals namely Pb2+, Cu2+, Zn2+, Cd2+ and Ni2+ in aqueous solutions was investigated. The metal fixation capacities of the sorbent were determined according to operating conditions and the fixation mechanisms were identified. The biopolymer has shown high elimination rates and interesting metal fixation capacities. A pseudo-second-order kinetic model was tested to investigate the adsorption mechanisms. The kinetic parameters of the model were calculated and discussed. For 8 × 10-4 M initial metal concentration, the initial sorption rates (v0) ranged from 0.063 mmol.g-1.min-1 for Pb2+ to 0.275 mmol.g-1.min-1 for Ni2+ ions, with the order: Ni2+ > Cd2+ > Zn2+ > Cu2+ > Pb2+. The equilibrium data fitted well with the Langmuir model and showed the following affinity order of the material: Pb2+ > Cu2+ > Zn2+ > Cd2+ > Ni2+. Then, the kinetic and equilibrium parameters calculated qm and v0 were tentatively correlated to the properties of the metals. Finally, equilibrium experiments in multimetallic systems were performed to study the competition of the fixation of Pb2+, Zn2+ and Ni2+ cations. In all cases, the metal fixation onto the biopolymer was found to be favourable in multicomponent systems. Based on these results, it is demonstrated that this biosorbent represents a low-cost solution for the treatment of metal-polluted wastewaters.

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An Anti-Counterfeiting Architecture for Traceability System Based on Modified Two-Level Quick Response Codes

Electronics ◽

10.3390/electronics10030320 ◽

2021 ◽

Vol 10 (3) ◽

pp. 320

Author(s):

Shundao Xie ◽

Hong-Zhou Tan

Keyword(s):

Product Life Cycle ◽

Low Cost ◽

Prototype System ◽

Qr Code ◽

Quick Response ◽

Copy Detection ◽

Traceability System ◽

Scanned Image ◽

Promising Solution ◽

Product Package

Traceability is considered a promising solution for product safety. However, the data in the traceability system is only a claim rather than a fact. Therefore, the quality and safety of the product cannot be guaranteed since we cannot ensure the authenticity of products (aka counterfeit detection) in the real world. In this paper, we focus on counterfeit detection for the traceability system. The risk of counterfeiting throughout a typical product life cycle in the supply chain is analyzed, and the corresponding requirements for the tags, packages, and traceability system are given to eliminate these risks. Based on the analysis, an anti-counterfeiting architecture for traceability system based on two-level quick response codes (2LQR codes) is proposed, where the problem of counterfeit detection for a product is transformed into the problem of copy detection for the 2LQR code tag. According to the characteristics of the traceability system, the generation progress of the 2LQR code is modified, and there is a corresponding improved algorithm to estimate the actual location of patterns in the scanned image of the modified 2LQR code tag to improve the performance of copy detection. A prototype system based on the proposed architecture is implemented, where the consumers can perform traceability information queries by scanning the 2LQR code on the product package with any QR code reader. They can also scan the 2LQR code with a home-scanner or office-scanner, and send the scanned image to the system to perform counterfeit detection. Compared with other anti-counterfeiting solutions, the proposed architecture has advantages of low cost, generality, and good performance. Therefore, it is a promising solution to replace the existing anti-counterfeiting system.

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Kinetics and isotherm modeling of Pb(II) and Cd(II) sequestration from polluted water onto tropical ultisol obtained from Enugu Nigeria

Applied Water Science ◽

10.1007/s13201-021-01402-8 ◽

2021 ◽

Vol 11 (4) ◽

Author(s):

Theresa C. Umeh ◽

John K. Nduka ◽

Kovo G. Akpomie

Keyword(s):

Metal Ions ◽

Low Cost ◽

Water Environment ◽

Standard Technique ◽

Soil Surface ◽

Cost Effective ◽

Polluted Water ◽

Batch Adsorption ◽

Lead And Cadmium ◽

Pseudo Second Order

AbstractDeterioration in soil–water environment severely contributed by heavy metal bioavailability and mobility on soil surface and sub-surface due to irrational increase in wastewater discharge and agrochemical activities. Therefore, the feasibility of adsorption characteristics of the soil is paramount in curbing the problem of micropollutant contamination in the farming vicinity. Soil from a farming site in a populated area in Enugu, Nigeria was collected and tested to measure the lead and cadmium contents using atomic absorption spectrophotometer (AAS). The adsorption potency of the ultisol soil was estimated for identifiable physicochemical properties by standard technique. The mean activity concentration of Pb2+ and Cd2+ was 15.68 mg/kg and 3.01 mg/kg. The pH, temperature, metal concentration and contact time adsorptive effect on the Pb2+ and Cd2+ uptake was evaluated by batch adsorption technique. The Langmuir, Freundlich and Temkin models were fitted into equilibrium adsorption data and the calculated results depict a better and satisfactory correlation for Langmuir with higher linear regression coefficients (Pb2+, 0.935 and Cd2+, 0.971). On the basis of sorption capacity mechanism of the soil, pseudo-second-order model best described the kinetics of both metal ions retention process. The results of the present study indicated that the soil being a low cost-effective adsorbent can be utilized to minimize the environmental risk impact of these metal ions.

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Removal of Chromium(III) and Cadmium(II) Heavy Metal Ions from Aqueous Solutions Using Treated Date Seeds: An Eco-Friendly Method

Molecules ◽

10.3390/molecules26123718 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3718

Author(s):

Mohammad Azam ◽

Saikh Mohammad Wabaidur ◽

Mohammad Rizwan Khan ◽

Saud I. Al-Resayes ◽

Mohammad Shahidul Islam

Keyword(s):

Metal Ions ◽

Adsorption Capacity ◽

Low Cost ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

Surface Analysis Techniques ◽

Adsorption Processes ◽

Ft Ir ◽

Metal Elution ◽

Date Pits

The aim of the research was to prepare low-cost adsorbents, including raw date pits and chemically treated date pits, and to apply these materials to investigate the adsorption behavior of Cr(III) and Cd(II) ions from wastewater. The prepared materials were characterized using SEM, FT-IR and BET surface analysis techniques for investigating the surface morphology, particle size, pore size and surface functionalities of the materials. A series of adsorption processes was conducted in a batch system and optimized by investigating various parameters such as solution pH, contact time, initial metal concentrations and adsorbent dosage. The optimum pH for achieving maximum adsorption capacity was found to be approximately 7.8. The determination of metal ions was conducted using atomic adsorption spectrometry. The experimental results were fitted using isotherm Langmuir and Freundlich equations, and maximum monolayer adsorption capacities for Cr(III) and Cd(II) at 323 K were 1428.5 and 1302.0 mg/g (treated majdool date pits adsorbent) and 1228.5 and 1182.0 mg/g (treated sagai date pits adsorbent), respectively. It was found that the adsorption capacity of H2O2-treated date pits was higher than that of untreated DP. Recovery studies showed maximal metal elution with 0.1 M HCl for all the adsorbents. An 83.3–88.2% and 81.8–86.8% drop in Cr(III) and Cd(II) adsorption, respectively, were found after the five regeneration cycles. The results showed that the Langmuir model gave slightly better results than the Freundlich model for the untreated and treated date pits. Hence, the results demonstrated that the prepared materials could be a low-cost and eco-friendly choice for the remediation of Cr(III) and Cd(II) contaminants from an aqueous solution.

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