scholarly journals Nutshells as Efficient Biosorbents to Remove Cadmium, Lead, and Mercury from Contaminated Solutions

2021 ◽  
Vol 18 (4) ◽  
pp. 1580
Author(s):  
Mariana Dias ◽  
João Pinto ◽  
Bruno Henriques ◽  
Paula Figueira ◽  
Elaine Fabre ◽  
...  
Keyword(s):  
Mineral Water ◽  
Low Cost ◽  
Water Remediation ◽  
Contaminated Water ◽  
Ultrapure Water ◽  
Cadmium Lead ◽  
Main Components ◽  
Hazelnut Shells ◽  
Complexity Increase ◽  
Cd Removal

The release of potentially toxic elements into the environment, and their effects on aquatic ecosystems still present a real threat. To avoid such contamination, the use of biological sorbents as an alternative to conventional and expensive water remediation techniques has been proposed. The present study evaluated the potential of 0.5 g L−1 of peanut, hazelnut, pistachio, walnut, and almond shells to remove the requisite concentrations of cadmium (Cd), lead (Pb), and mercury (Hg) from contaminated water. Hazelnut shells were identified as the sorbent with the highest potential and were evaluated in mono- and multi-contaminated mineral water. The influence of sorbent-intrinsic and solution-intrinsic characteristics were assessed. Differences among sorbents were attributed to varying percentages of their main components: cellulose, hemicellulose, and lignin. Matrix complexity increase caused a decrease in Cd removal, presumably due to the diminution in electrostatic interaction, and complexation with anions such as Cl−. When simultaneously present in the solution, contaminants competed, with Pb showing higher affinity to the sorbent than Hg. High efficiencies (>90%) obtained for hazelnut shells for all elements in ultrapure water and for Pb and Hg in mineral water) reveals the high potential of this low-cost and abundant waste for use in the remediation of contaminated waters (circular economy).

scholarly journals Recent Developments in Water Treatment by Cellulose Aerogels from Agricultural Waste

2021 ◽  
Vol 947 (1) ◽  
pp. 012011
Author(s):  
Phuong X T Nguyen ◽  
Kim H Ho ◽  
Chi T X Nguyen ◽  
Nga H N Do ◽  
Anh P N Pham ◽  
...  
Keyword(s):  
Water Treatment ◽  
Low Cost ◽  
Agricultural Waste ◽  
Value Added ◽  
Water Remediation ◽  
Contaminated Water ◽  
Research Directions ◽  
Modern Age ◽  
Removal Of Heavy Metals ◽  
Recent Developments

Abstract Water pollution caused by inorganic and organic compounds affects seriously health risks and the destruction of the water balance of the ecosystem. Water remediation is one of the greatest challenges of the modern age, which is faced by several countries in over the world. Many advanced technologies have been developed in recent years to manage this alarming problem. One of the recent research directions is to utilize agricultural waste, which is an abundant, low-cost, eco-friendly source, to manufacture cellulose aerogels for the removal of heavy metals, dyes, and oils from contaminated water. This review paper focuses on the latest green fabrication of bio-aerogels from various cellulose-based plant waste and studies on the kinetics and influence of factors such as contact time, pH solution, initial concentration, and temperature on the adsorption process to better understand the mechanisms of water treatment by the cellulose aerogels. Based on the discussion and summary, the potential of agro-waste sources in their value-added chain by developing efficient water treatment cellulose aerogels is comprehensively overviewed.

Parameters Affecting Dye Adsorption - Using Graphene Coated Sand (GSC)

2018 ◽  
Vol 4 (02) ◽  
Author(s):  
Seroor Atalah Khaleefa Alia ◽  
Dr. Mohammed Ibrahimb ◽  
Hussein Ali Hussein
Keyword(s):  
Heavy Metals ◽  
Contact Time ◽  
Organic Dyes ◽  
Low Cost ◽  
Dye Adsorption ◽  
Contaminated Water ◽  
Maximum Adsorption Capacity ◽  
Engineering Designs ◽  
Heavy Metals Ions ◽  
Coated Sand

Adsorption is most commonly applied process for the removal of pollutants such as dyes and heavy metals ions from wastewater. The present work talks about preparing graphenic material attached sand grains called graphene sand composite (GSC) by using ordinary sugar as a carbon source. Physical morphology and chemical composition of GSC was examined by using (FTIR, SEM, EDAX and XRD). Efficiency of GSC in the adsorption of organic dyes from water was investigated using reactive green dye with different parameters such as (ph, temperature, contact time and dose). Adsorption isotherm was also studied and the results showed that the maximum adsorption capacity of dye is 28.98 mg/g. This fast, low-cost process can be used to manufacture commercial filters to treat contaminated water using appropriate engineering designs.

scholarly journals Eggshell Powder as an Adsorbent for Removal of Fluoride from Aqueous Solution: Equilibrium, Kinetic and Thermodynamic Studies

2012 ◽  
Vol 9 (3) ◽  
pp. 1457-1480 ◽  
Author(s):  
R. Bhaumik ◽  
N. K. Mondal ◽  
B. Das ◽  
P. Roy ◽  
K. C. Pal ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Fluoride Removal ◽  
Contaminated Water ◽  
Fluoride Adsorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Kinetic And Thermodynamic Studies ◽  
Maximum Removal

A new medium, eggshell powder has been developed for fluoride removal from aqueous solution. Fluoride adsorption was studied in a batch system where adsorption was found to be pH dependent with maximum removal efficiency at 6.0. The experimental data was more satisfactorily fitted with Langmuir isotherm model. The kinetics and the factor controlling adsorption process fully accepted by pseudo-second-order model were also discussed. Eawas found to be 45.98 kJmol-1by using Arrhenius equation, indicating chemisorption nature of fluoride onto eggshell powder. Thermodynamic study showed spontaneous nature and feasibility of the adsorption process with negative enthalpy (∆H0) value also supported the exothermic nature. Batch experiments were performed to study the applicability of the adsorbent by using fluoride contaminated water collected from affected areas. These results indicate that eggshell powder can be used as an effective, low-cost adsorbent to remove fluoride from aqueous solution as well as groundwater.

Highly Efficient and Low‐cost Clay‐based Adsorbent for Glyphosate Removal from Contaminated Water

2021 ◽  
Author(s):  
Farzana Nargis ◽  
Ann Duong ◽  
Erwin Rehl ◽  
Charles Bradshaw ◽  
Hossein Kazemian
Keyword(s):  
Low Cost ◽  
Contaminated Water ◽  
Highly Efficient

Comparison of diffused layer prepared using liquid dopant solutions and pastes for solar cell with screen printed electrodes

2016 ◽  
Vol 33 (3) ◽  
pp. 167-171 ◽  
Author(s):  
Kazimierz Drabczyk ◽  
Edyta Wróbel ◽  
Grazyna Kulesza-Matlak ◽  
Wojciech Filipowski ◽  
Krzysztof Waczynski ◽  
...  
Keyword(s):  
Solar Cells ◽  
Ethyl Alcohol ◽  
Diffusion Processes ◽  
Phosphorus Oxychloride ◽  
Low Cost ◽  
Content Type ◽  
Base Solution ◽  
Different Types ◽  
Main Components ◽  
Two Stages

Purpose The purpose of this study is comparison of the diffusion processes performed using the commercial available dopant paste made by Filmtronics and the original prepared liquid dopant solution. To decrease prices of industrially produced silicon-based solar cells, the new low-cost production processes are necessary. The main components of most popular silicon solar cells are with diffused emitter layer, passivation, anti-reflective layers and metal electrodes. This type of cells is prepared usually using phosphorus oxychloride diffusion source and metal pastes for screen printing. The diffusion process in diffusion furnace with quartz tube is slow, complicated and requires expensive equipment. The alternative for this technology is very fast in-line processing using the belt furnaces as an equipment. This approach requires different dopant sources. Design/methodology/approach In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution. The investigation was focused on dopant sources fabrication and diffusion processes. The doping solution was made in two stages. In the first stage, a base solution (without dopants) was made: dropwise deionized (DI) water and ethyl alcohol were added to a solution consisting of tetraethoxysilane (TEOS) and 99.8 per cent ethyl alcohol. Next, to the base solution, orthophosphoric acid dissolved in ethyl alcohol was added. Findings Diffused emitter layers with sheet resistance around 60 Ω/sq were produced on solar grade monocrystalline silicon wafers using two types of dopant sources. Originality/value In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution.

scholarly journals Removal of Cyanide-Contaminated Water by Vetiver Grasses

2015 ◽  
Vol 9 (13) ◽  
pp. 252 ◽  
Author(s):  
Piyada Wachirawongsakorn ◽  
Tongsai Jamnongkan ◽  
Mohd Talib Latif
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Sri Lanka ◽  
Removal Efficiency ◽  
Water Samples ◽  
Low Cost ◽  
Contaminated Water ◽  
Vetiver Grass ◽  
Vetiveria Zizanioides ◽  
Concentration Levels

<p>Vetiver grass and it usages have been widely investigated in many researches as the preferred plant species due to its known efficiency, low cost, the ease of availability and spread. This research aimed to use four different vetiver grass (<em>Vetiveria zizanioides</em>) ecotypes to remove cyanide (CN<sup>-</sup>)-contaminated water for improve its quality. Growth capability, tolerance and removal efficiency were evaluated. The results showed that the vetiver grass had a 100% survival rate for one month after planting. Songkhlar3 had the longest leaves, followed by Surat-Thani, Sri Lanka and Monto, respectively. Root lengths of all ecotypes showed no significant differences (p ≤ 0.05). All vetiver grass ecotypes could potentially purify CN<sup>-</sup>-contaminated water at lower concentrations of ≤ 35 mg CN<sup>-</sup>/L. The Monto ecotype had the highest CN<sup>-</sup> removal efficiency at all CN<sup>-</sup> concentration levels, showing 100% CN<sup>-</sup> removal from the 5-45 mg CN<sup>-</sup>/L contaminated water samples within 2-5 weeks growth. The tolerance of vetiver grass to CN<sup>-</sup> was a more important factor than growth rate when selecting a vetiver grass ecotype for CN<sup>-</sup> phytoremediation.</p>

Design of a Teaching Robot with Three Degrees of Freedom

2012 ◽  
Vol 619 ◽  
pp. 325-328
Author(s):  
You Jun Huang ◽  
Ze Lun Li ◽  
Zhi Cheng Huang
Keyword(s):  
Degrees Of Freedom ◽  
Low Cost ◽  
Degree Of Freedom ◽  
Good Repeatability ◽  
Main Components ◽  
Opening And Closing ◽  
Three Degree Of Freedom ◽  
Three Degrees Of Freedom ◽  
Application Prospects

A teaching robot with three degree of freedom is designed. The three degrees of freedom are: waist rotation, lifting and stretching of the arm and opening and closing of the gripper. The designs of the main components are: a mobile chassis, parallel rails, horizontal rails and manipulator. The teaching robot designed has the features of low cost, easy to regulation, good repeatability and it has good promotion and application prospects in the field of teaching.

scholarly journals Performance Evaluation of Low-Cost Filter in Field Condition

2021 ◽  
pp. 20-26
Author(s):  
K. Nagarajan ◽  
S. Ramya ◽  
T. Thangamani ◽  
A. Selvaperumal ◽  
T. Arthi
Keyword(s):  
Irrigation System ◽  
Low Cost ◽  
Cost Effective ◽  
Water Source ◽  
Filter Media ◽  
Micro Irrigation ◽  
Main Components ◽  
Filtration Unit ◽  
Solids Removal ◽  
Media Layer

The parameters require for maintaining the crop's health and the integrity of the irrigation system has a relation with quality of irrigation water. In Micro irrigation appropriate filtration is very much important to prevent clogging. Filtration unit is one of the main components in micro irrigation system that too, Primary filter is more important to be installed along with the unit, when the water source is from open reservoir and other water sources. Though it is essential, the primary filter is not being installed by the farmers due to its high cost. Hence this study is an attempt to fabricate low-cost filter and to evaluate its performance with different filter media layer. A low-cost primary filter for drip irrigation system is fabricated. Different filter media layer like silex sand (fine silex, coarse silex), pebbles with different sizes are selected. The results revealed that the removal efficiency of filter using silex sand and pebbles were 71% in terms of turbidity, 78% in terms of total suspended solids removal at flow rate of 12 m3 /hr. This fabricated low-cost filter will be cost effective for small farm applications.

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