scholarly journals Modified Ziziphus spina-christi stones as green route for the removal of heavy metals

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Eman A. Assirey ◽  
Shadia M. Sirry ◽  
Hayfaa A. Burkani ◽  
Medhat A. Ibrahim
Keyword(s):  
Heavy Metals ◽  
Maximum Adsorption Capacity ◽  
Characteristic Functional ◽  
Chemically Modified ◽  
Green Route ◽  
Removal Of Heavy Metals ◽  
Ternary Metal ◽  
Uptake Process ◽  
And Control ◽  
By Products

AbstractGreen routes for remediation of heavy metals are worldwide challenges to overcome pollution problems on one hand and control the adverse impact of chemicals on the other hand. Biosorption is one of the most effective methods for removing lower level of heavy metals. The idea to apply natural resources as a green method for removal of heavy metals, this route has no adverse impacts on the environment. This study investigated the ability of chemically modified Ziziphus spina-christi stones (ZSCs) as agriculture by-products to perform the biosorption of Pb(II), Zn(II) and Cd(II) ions from wastewater in a single and ternary metal system. The characteristic functional groups of chemically modified ZSCs were analyzed by Fourier transform infrared. In comparison with acidic ZSCs, alkali-modified ZSCs by KOH was more effective and enhanced the removal efficiency of ZSCs. Using Langmuir isotherm, the maximum adsorption capacity on the modified ZSCs for Pb(II) was 9.06 mg/g, for Zn(II) obtained by using ZSC–citric acid was 4.19 mg/g and 5.38 mg/g for Cd(II) as obtained by using ZSC–H2O2. The molecular electrostatic potential, which was calculated at B3LYP/6-31G(d,p), indicated that each metal is di-hydrated, forming a complex with two units of amino acids. This mechanism demonstrated the uptake process by ZSCs.

scholarly journals Sawdust for the Removal of Heavy Metals from Water: A Review

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4318
Author(s):  
Elie Meez ◽  
Abbas Rahdar ◽  
George Z. Kyzas
Keyword(s):  
Heavy Metals ◽  
Adsorption Mechanism ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Suitable Material ◽  
Removal Of Heavy Metals ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
And Control ◽  
Environmental Agencies

The threat of the accumulation of heavy metals in wastewater is increasing, due to their abilities to inflict damage to human health, especially in the past decade. The world’s environmental agencies are trying to issue several regulations that allow the management and control of random disposals of heavy metals. Scientific studies have heavily focused on finding suitable materials and techniques for the purification of wastewaters, but most solutions have been rejected due to cost-related issues. Several potential materials for this objective have been found and have been compared to determine the most suitable material for the purification process. Sawdust, among all the materials investigated, shows high potential and very promising results. Sawdust has been shown to have a good structure suitable for water purification processes. Parameters affecting the adsorption mechanism of heavy metals into sawdust have been studied and it has been shown that pH, contact time and several other parameters could play a major role in improving the adsorption process. The adsorption was found to follow the Langmuir or Freundlich isotherm and a pseudo second-order kinetic model, meaning that the type of adsorption was a chemisorption. Sawdust has major advantages to be considered and is one of the most promising materials to solve the wastewater problem.

The Behaviors of Removing Silver Ions by Low-Cost Expanded Rice Husk, Nature Diatomite and Nature Bentonite as Sorbents

2012 ◽  
Vol 724 ◽  
pp. 472-475
Author(s):  
Xuan Liang ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Qiang Mei
Keyword(s):  
Adsorption Capacity ◽  
Rice Husk ◽  
Ph Value ◽  
Low Cost ◽  
Silver Ions ◽  
Maximum Adsorption Capacity ◽  
Removal Of Heavy Metals ◽  
Initial Ph ◽  
Influence Of Ph ◽  
By Products

Low cost industrial and agricultural by-products are promising materials for water pollution treatment such as removal of heavy metals. This work deals with removal of silver ions from solutions using expanded rice husk (ERH), nature diatomite (ND) and nature bentonite (NB). Firstly the influence of pH value of the solution on adsorption capacity for silver ions was studied, and then the effect of initial silver concentration on adsorbents adsorption capacity was investigated. The silver ions removal percentage increases with initial pH and achieves a maximum value of nearly 94% at pH= 5.0 ± 0.5 for ERH. The maximum adsorption capacity is 18.6 mg/g for ERH.

Removal of heavy metals from aqueous phases using chemically modified waste Lyocell fiber

2015 ◽  
Vol 299 ◽  
pp. 550-561 ◽  
Author(s):  
John Kwame Bediako ◽  
Wei Wei ◽  
Sok Kim ◽  
Yeoung-Sang Yun
Keyword(s):  
Heavy Metals ◽  
Chemically Modified ◽  
Removal Of Heavy Metals ◽  
Lyocell Fiber

Study on the Removal of Heavy Metals by Biomass

2013 ◽  
Vol 634-638 ◽  
pp. 276-279
Author(s):  
Neng Zhou ◽  
Zhen Zhou ◽  
Yuan Qin ◽  
Chu Jie Zeng
Keyword(s):  
Heavy Metals ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Room Temperature ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Experimental Conditions ◽  
Adsorption Time ◽  
Removal Of Heavy Metals ◽  
Efficient Adsorbent

In this paper, the adsorption of heavy metals by biomass, namely dry garlic stem, an environmentally-friendly and natural adsorbent, were studied．The efficiency of the adsorbent was studied under different experimental conditions by varying parameters such as pH, initial concentration and contact time using batch adsorption technique. The results show that at pH 5.50, room temperature, the adsorption time 90 min and the amount of garlic stem 0.5 g, Co2+ have the maximum adsorption capacity. The maximum adsorption capacity of the Co2+ on garlic stem is 14.9 mg/g. At pH 9.50, the adsorption time 90 min and the amount of garlic stem 0.7g, Cd2+ have the maximum adsorption at the same temperature. The maximum adsorption of the Cd2+ is 20.90 mg/g. At pH 10.0, the adsorption time 150 min and the amount of garlic stem 0.3g, Ni2+ have the maximum adsorption at the same temperature. The dry garlic stem is a efficient adsorbent in removing cobalt, cadmium and nickel from aqueous solution.

Competitive Adsorption of Lead and Copper by Kaolin

2014 ◽  
Vol 1073-1076 ◽  
pp. 784-790
Author(s):  
Obed Osei Anokye ◽  
Chun Lei Zhang
Keyword(s):  
Heavy Metals ◽  
Adsorption Capacity ◽  
Competitive Adsorption ◽  
Binary Solution ◽  
Maximum Adsorption Capacity ◽  
Metal Solution ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Removal Of Heavy Metals ◽  
Separation Factors

Due to the potential of kaolin as an adsorbent for removal of heavy metals from solution, the competitive adsorption of Lead (Pb) and Copper (Cu) by kaolin was investigated to provide further understanding on the binding behaviors and capacities of these two metals onto kaolin. The Langmuir and Freundlich isotherms were applied to further explain the competition between the metals. Three different solutions were used, each at concentrations 10, 20, 30, 45, 60 and 75mg/L: single-metal solution of Pb (Pb-Only), single-metal solution of Cu (Cu-Only), and solution of both metals at the same concentrations (Binary solution). The kaolin adsorbed Pb about twice more than Cu, both for the binary solution and for the single-metal solutions. This correlated well with predictions of maximum adsorption capacity (Q) for kaolin, where Q for Pb was about twice as much as that for Cu, both in the binary solution and in the single-metal solution. Competition from Cu in binary solution reduced Pb adsorption by 9%, while Cu rather increased by 4.1%, relative to their respective adsorptions in Pb-Only and Cu-Only, respectively. However, during competitive adsorption in the binary solution, the relative proportions of adsorbed Pb increased by 11.4% as the initial metals concentration increased from 10 – 75mg/L, while that of Cu reduced by the same proportion. This was explainable by their respective separation factors (RL), which indicated higher favorability of kaolin for Pb than for Cu. Furthermore, bonding energy (KL) of Pb unto kaolin during competition was about 2.5 times that of Cu, and was likely able to cause Pb to displace Cu from kaolin surface. This study reveals greater adsorption capacity of kaolin for Pb than for Cu, and could provide the basis for future projects/studies that would employ kaolin in Pb and Cu removal.

scholarly journals A Study on Adsorption of Heavy Metals with Zeolite and FeS Media

2020 ◽  
Vol 42 (7) ◽  
pp. 349-359
Author(s):  
Gimin Lee ◽  
Gyuri Kim ◽  
Sungkyu Choi ◽  
Tae-jin Lee
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Reaction Kinetics ◽  
Adsorption Capacity ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Adsorption Characteristics ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order ◽  
Kinetics Of

Objectives:Adsorption characteristics in aqueous solution were investigated to effectively remove heavy metals by the crystallization of FeS and reaction kinetics were analyzed to compare with heavy metal adsorption characteristics of zeolite.Methods:The adsorption characteristics of each media were analyzed using Langmuir adsorption isotherm, and the adsorption reaction kinetics of heavy metals (Pb, Cu, Zn) on zeolite and FeS media were analyzed by a pseudo-first or pseudo-second order reaction kinetics.Results and Discussion:The maximum adsorption capacity of zeolite was highest in Pb, and the adsorption preference was in the order of Pb>Cu>Zn. In the case of FeS media, Cu was found to have a higher adsorption capacity than Pb or Zn, and the adsorption preference was observed to be Cu>Pb>Zn. It was found that the adsorption mechanism is based on chemical adsorption (chemisorption) because adsorption of each heavy metal onto zeolite or FeS media is more suitable for pseudo-second order kinetics.Conclusions:It was found that the removal of heavy metals through FeS media has a different pattern from zeolite, and when comparing the adsorption capacity of each media, it was found that FeS media is more effective for Zn or Cu except Pb.

Applicability of agricultural waste and by-products for adsorptive removal of heavy metals from wastewater

2013 ◽  
Vol 148 ◽  
pp. 574-585 ◽  
Author(s):  
T.A.H. Nguyen ◽  
H.H. Ngo ◽  
W.S. Guo ◽  
J. Zhang ◽  
S. Liang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Agricultural Waste ◽  
Adsorptive Removal ◽  
Removal Of Heavy Metals ◽  
By Products

Adsorption performance of magnetic aminated lignin for the removal of Cu(II) and Cd(II)

TAPPI Journal ◽  
2019 ◽  
Vol 18 (01) ◽  
pp. 9-18
Author(s):  
Dafeng Zheng ◽  
Yingzhi Ma ◽  
Xueqing Qiu ◽  
Xuejun Pan
Keyword(s):  
Heavy Metals ◽  
Entropy Change ◽  
Enthalpy Change ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Adsorption Performance ◽  
Monolayer Adsorption ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order

The adsorption behavior of Cu(II) and Cd(II) onto a magnetic lignin-based nanomaterial (MLN) was investigated in detail. The results showed that the adsorption isotherm was better described by the Langmuir model, showing monolayer adsorption with a maximum adsorption capacity of 135.7 and 156.5 mg/g. The kinetics fit the pseudo-second-order model. The thermodynamics showed the enthalpy change of the adsorption for Cu(II) and Cd(II) was 24.12 and 36.49 kJ/mol, with entropy change of 85.12 and 130.3 J/mol·K, respectively; thus, the adsorption was endothermic and spontaneous in the range of 25°C–45°C. Additionally, the adsorbent was easy to regenerate. This study shows that MLN is a capable, sustainable absorbent for the removal of heavy metals.

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