Stability of Nano-ZnO in simulated landfill leachate containing heavy metal ions

2020 ◽  
Vol 198 ◽  
pp. 110641
Author(s):  
Xiaoyu Li ◽  
Wenchuan Ding ◽  
Siying Tan ◽  
Xiaolan Zeng
2019 ◽  
Vol 61 (1) ◽  
pp. 81-87 ◽  
Author(s):  
Xin Xu ◽  
Xiaofeng Liu ◽  
Myounghak Oh ◽  
Junboum Park ◽  
Y. Frank Chen

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
Venkatesham V ◽  
Madhu G.M ◽  
Satyanarayana S V ◽  
Preetham H S

Large amount of heavy metal ions disposed in wastewater by various industries causes environmental pollution and toxicity in waste water. Many naturally available materials were used as adsorbents for the removal of heavy metal ions, but they are not effective because of low surface area. Novel nano materials are used as adsorbents in the removal of metal ions to treat potable water. In the present work nano sized large surface area (80.425 m2/g) Zinc Oxide (ZnO) was synthesized by gel combustion method and used as an adsorbent for the removal of cadmium (II) (Cd2+) from aqueous solution. The nano ZnO and Cd adsorbed ZnO were characterized by XRD, the additional Cd peaks in XRD pattern confirms the Cd adsorption. SEM analysis confirmed the adsorption of Cd2+ by change in the morphology of adsorbent. Percentage purity of the element and the presence of the Cd were characterized by EDAX. Adsorption of Cd2+ on ZnO was confirmed by varying parameters like initial concentration, pH and adsorbent dosage. Cadmium concentration in the solution was analyzed using Atomic Absorption Spectrometer (AAS). Increase in the initial concentration of Cd solution, decreases the percentage of adsorption, where as increase in the adsorbent dosage and pH of the solution increases the adsorption of Cd2+ on ZnO. Synthesized nano ZnO shows maximum of 95% Cd adsorption at lower initial concentration. Experimental data fits Langmuir and Freundlich adsorption isotherm models.


2017 ◽  
Vol 14 (1) ◽  
pp. 15
Author(s):  
M.B. Nicodemus Ujih ◽  
Mohammad Isa Mohamadin ◽  
Milla-Armila Asli ◽  
Bebe Norlita Mohammed

Heavy metal ions contamination has become more serious which is caused by the releasing of toxic water from industrial area and landfill that are very harmful to all living organism especially human and can even cause death if contaminated in small amount of heavy metal concentration. Currently, peoples are using classic method namely electrochemical treatment, chemical oxidation/reduction, chemical precipitation and reverse osmosis to eliminate the metal ions from toxic water. Unfortunately, these methods are costly and not environmentally friendly as compared to bioadsorption method, where agricultural waste is used as biosorbent to remove heavy metals. Two types of agricultural waste used in this research namely oil palm mesocarp fiber (Elaesis guineensis sp.) (OPMF) and mangrove bark (Rhizophora apiculate sp.) (MB) biomass. Through chemical treatment, the removal efficiency was found to improve. The removal efficiency is examined based on four specification namely dosage, of biosorbent to adsorb four types of metals ion explicitly nickel, lead, copper, and chromium. The research has found that the removal efficiency of MB was lower than OPMF; whereas, the multiple metals ions removal efficiency decreased in the order of Pb2+ > Cu2+ > Ni2+ > Cr2+.


2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).


2020 ◽  
Vol 13 ◽  
Author(s):  
Rishabha Malviya ◽  
Pramod Sharma ◽  
Akanksha Sharma

: Manuscript discussed about the role of polysaccharides and their derivatives in the removal of metal ions from industrial waste water. Quick modernization and industrialization increases the amount of various heavy metal ions in the environment. They can possess various disease in humans and also causes drastic environmental hazards. In this review the recent advancement for the adsorption of heavy metal ions from waste water by using different methods has been studied. Various natural polymers and their derivatives are act as effective adsorbents for the removal of heavy metal ions from the waste water released from the industries and the treated water released into the environment can decreases the chances of diseases in humans and environmental hazards. From the literature surveys it was concluded that the removal of heavy metal ions from the industrial waste water was important to decrease the environmental pollution and also diseases caused by the heavy metal ions. Graft copolymers were acts as most efficient adsorbent for the removal of heavy metal ions and most of these followed the pseudo first order and pseudo second order model of kinetics.


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