Removal of heavy metals from aqueous media using native cassava starch hydrogel

2012 ◽  
Vol 6 (7) ◽  
Author(s):  
L. O. Ekebafe
Keyword(s):  
Heavy Metals ◽  
Aqueous Media ◽  
Cassava Starch ◽  
Removal Of Heavy Metals

scholarly journals Optimization of process parameters for heavy metals biosorption onto mustard waste biomass

2016 ◽  
Vol 14 (1) ◽  
pp. 175-187 ◽  
Author(s):  
Lăcrămioara (Negrilă) Nemeş ◽  
Laura Bulgariu
Keyword(s):  
Heavy Metals ◽  
Aqueous Media ◽  
Order Kinetic ◽  
Waste Biomass ◽  
Solution Ph ◽  
Biosorption Process ◽  
Optimization Of Process Parameters ◽  
Removal Of Heavy Metals ◽  
Equilibrium Data ◽  
Order Kinetic Model

AbstractMustard waste biomass was tested as a biosorbent for the removal of Pb(II), Zn(II) and Cd(II) from aqueous solution. This strategy may be a sustainable option for the utilization of such wastes. The influence of the most important operating parameters of the biosorption process was analyzed in batch experiments, and optimal conditions were found to include initial solution pH 5.5, 5.0 g biosorbent/L, 2 hours of contact time and high temperature. Kinetics analyses show that the maximum of biosorption was quickly reached and could be described by a pseudo-second order kinetic model. The equilibrium data were well fitted by the Langmuir model, and the highest values of maximum biosorption capacity were obtained with Pb(II), followed by Zn(II) and Cd(II). The thermodynamic parameters of the biosorption process (ΔG, ΔH and ΔS) were also evaluated from isotherms. The results of this study suggest that mustard waste biomass can be used for the removal of heavy metals from aqueous media.

scholarly journals A systematic study for removal of heavy metals from aqueous media using Sorghum bicolor: an efficient biosorbent

2018 ◽  
Vol 77 (10) ◽  
pp. 2355-2368 ◽  
Author(s):  
Khalida Naseem ◽  
Zahoor H. Farooqi ◽  
Muhammad Z. Ur Rehman ◽  
Muhammad A. Ur Rehman ◽  
Robina Begum ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Aqueous Media ◽  
Review Article ◽  
Isotherm Models ◽  
Adsorption Efficiency ◽  
Adsorption Isotherm Models ◽  
Removal Of Heavy Metals

Abstract This review is based on the adsorption characteristics of sorghum (Sorghum bicolor) for removal of heavy metals from aqueous media. Different parameters like pH, temperature of the medium, sorghum concentration, sorghum particle size, contact time, stirring speed and heavy metal concentration control the adsorption efficiency of sorghum biomass for heavy metal ions. Sorghum biomass showed maximum efficiency for removal of heavy metal ions in the pH range of 5 to 6. It is an agricultural waste and is regarded as the cheapest biosorbent, having high adsorption capacity for heavy metals as compared to other reported adsorbents, for the treatment of heavy metal polluted wastewater. Adsorption of heavy metal ions onto sorghum biomass follows pseudo second order kinetics. Best fitted adsorption isotherm models for removal of heavy metal ions on sorghum biomass are Langmuir and Freundlich adsorption isotherm models. Thermodynamic aspects of heavy metal ions adsorption onto sorghum biomass have also been elaborated in this review article. How adsorption efficiency of sorghum biomass can be improved by different physical and chemical treatments in future has also been elaborated. This review article will be highly useful for researchers working in the field of water treatment via biosorption processing. The quantitative demonstrated efficiency of sorghum biomass for various heavy metal ions has also been highlighted in different sections of this review article.

Микродвигатели новое направление создания технологий очистки воды и сточных вод (обзор)

2019 ◽  
pp. 54-60
Author(s):  
V. Kofman
Keyword(s):  
Heavy Metals ◽  
Catalytic Properties ◽  
Aqueous Media ◽  
Ultrasonic Waves ◽  
Water Disinfection ◽  
Energy Sources ◽  
Chemical Gradients ◽  
Electric And Magnetic Fields ◽  
Removal Of Heavy Metals ◽  
Autonomous Movement

Микродвигатели представляют собой автономные, выполняющие определенные функции самодвижущиеся микроустройства на основе неорганических, органических или биологических материалов. В конструкции микродвигателя реализованы две функции: автономное движение и эффективный захват и/или деструкция различных химических веществ, в том числе загрязняющих. Для обеспечения автономного движения устройство микродвигателей предусматривает создание локальных термических, акустических, химических градиентов, проистекающих из ассиметричной морфологии или поверхностной структуры. Движение обеспечивается за счет использования различных источников энергии, включая свет, электрические и магнитные поля, ультразвуковые волны или химическое топливо . Хаотичная траектория движения микродвигателей в объеме раствора обеспечивает высокоэффективное взаимодействие иммобилизованных на их поверхности реагентов с целевыми загрязняющими или детектируемыми веществами. Наиболее проработанный принцип создания автономного движения заключается в возникновении импульса отдачи при ассиметричном образовании в результате химической реакции газовых микропузырей. В настоящее время основные исследования применения микродвигателей в процессах водоочистки проводятся по направлениям анализа водных сред, удаления тяжелых металлов, органических загрязняющих веществ, красителей и нефтепродуктов, а также обеззараживания воды. По оценкам, микродвигателям присущи уникальные возможности в области детектирования и удаления загрязняющих веществ в водной среде вследствие сочетания адсорбционных и каталитических свойств с автономным перемещением.Micromotors are autonomous, performing certain functions, selfpropelled microdevices based on inorganic, organic or biological materials. Implemented in a micromotor design are two functions: autonomous movement and effective capture and/or destruction of various chemicals, including pollutants. To ensure autonomous movement the micromotor device provides for the creation of local thermal, acoustic, chemical gradients arising from asymmetric morphology or surface structure. The movement is provided through the use of various energy sources including light, electric and magnetic fields, ultrasonic waves or chemical fuel. The chaotic trajectory of micromotors throughout the solution provides for the highly efficient interaction of the chemicals immobilized on their surface with the targeted pollutants or detectable substances. The most elaborated principle of creating autonomous movement is the generation of a recoil impulse at asymmetric formation of gas microbubbles as a result of a chemical reaction. Currently, the main studies on the use of micromotors in water purification processes are carried out in the areas of analysis of aqueous media, removal of heavy metals, organic pollutants, dyes and oil products, as well as water disinfection. It is estimated that micromotors possess unique capabilities in the field of detection and removal of pollutants in aqueous media due to a combination of adsorption and catalytic properties with autonomous movement.

scholarly journals Magnetic Hydroxyapatite for Batch Adsorption of Heavy Metals

2021 ◽  
Vol 287 ◽  
pp. 04005
Author(s):  
Khee Chung Hui ◽  
Norashikin Ahmad Kamal ◽  
Nonni Soraya Sambudi ◽  
Muhammad Roil Bilad
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Removal ◽  
Aqueous Media ◽  
Heavy Metal Removal ◽  
Calcium Nitrate ◽  
Chemical Precipitation ◽  
Batch Adsorption ◽  
Calcium Nitrate Tetrahydrate ◽  
Removal Of Heavy Metals

In this work, magnetic hydroxyapatite or hydroxyapatite-iron (III) oxide (HAp-Fe3O4) composite was used as the adsorbent of heavy metals and the performance was evaluated using the batch test. The presence of heavy metals in the effluent from wastewater discharge can be toxic to many organisms and can even lead to eye burns. Therefore, hydroxyapatite synthesized from the chemical precipitation of calcium nitrate tetrahydrate and diammonium hydrogen phosphate solutions is used to remove heavy metal in aqueous media. Magnetic properties of Fe3O4 can help prevent formation of secondary pollutants caused by the loss of adsorbent. The synthesized HAp-Fe3O4 can remove cadmium, zinc and lead effectively, which is up to 90% removal. Reusability study shows that the adsorbent could retain heavy metal ions even after four cycles. The percentage removal of heavy metals maintains at around 80% after four times of usage. The composite of HAp-Fe3O4 demonstrates good performance and stability which is beneficial for heavy metal removal in the future.

The potential of melt-mixed polypropylene–zeolite blends in the removal of heavy metals from aqueous media

2011 ◽  
Vol 36 (14-15) ◽  
pp. 1178-1188 ◽  
Author(s):  
Machawe M. Motsa ◽  
Justice M. Thwala ◽  
Titus A.M. Msagati ◽  
Bhekie B. Mamba
Keyword(s):  
Heavy Metals ◽  
Aqueous Media ◽  
Removal Of Heavy Metals

Removal of heavy metals from polluted aqueous media using berry leaf

2021 ◽  
pp. 1-17
Author(s):  
Ahmed H. Mangood ◽  
Ibrahim Abdelfattah ◽  
Fathy A. El-Saied ◽  
Mostafa Z. Mansour
Keyword(s):  
Heavy Metals ◽  
Aqueous Media ◽  
Removal Of Heavy Metals
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