Magnesium Oxide Embedded Nitrogen Self-Doped Biochar Composites: Fast and High-Efficiency Adsorption of Heavy Metals in an Aqueous Solution

2017 ◽  
Vol 51 (17) ◽  
pp. 10081-10089 ◽  
Author(s):  
Li-Li Ling ◽  
Wu-Jun Liu ◽  
Shun Zhang ◽  
Hong Jiang
2018 ◽  
Vol 18 (2) ◽  
pp. 265 ◽  
Author(s):  
Behzad Shamsi Zadeh ◽  
Hossein Esmaeili ◽  
Rauf Foroutan

Heavy metals are soluble in the environment and can be dangerous for many species. So, removal of heavy metals from the water and wastewater is an important process. In this study, an adsorbent made of eggshell powder was employed to remove cadmium ions from aqueous solution. A number of parameters were studied including pH of the aqueous solution, adsorbent dosage, contact time, the initial concentration of cadmium ion and mixing rate. The best efficiency for the removal of Cd(II) was obtained 96% using this adsorbent. The optimal parameters were ambient temperature of 30 °C, mixing rate of 200 rpm, pH of 9, an adsorbent dosage of 5 g/L and initial concentration of cadmium was 200 ppm. In order to study the kinetics of adsorbent, the pseudo-first-order and pseudo-second-order kinetic models and intra-particle diffusion model were applied. According to the pre-determined correlation coefficients (R2), the pseudo-second-order kinetic model showed a better correlation between the kinetic behaviors of the adsorbent. Furthermore, to study the equilibrium behavior of adsorbent, Langmuir and Freundlich models used and both models showed high efficiency in isotherm behavior of the adsorbent. So, this adsorbent can be used as a natural and cheap adsorbent.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Runlan Yu ◽  
Meilian Man ◽  
Zhaojing Yu ◽  
Xueling Wu ◽  
Li Shen ◽  
...  

AbstractIn polluted groundwater, surface water, and industrial sites, chromium is found as one of the most common heavy metals, and one of the 20 main pollutants in China, which poses a great threat to the ecological environment and human health. Combining biological and chemical materials to treat groundwater contaminated by heavy metals is a promising restoration technology. In this research, Klebsiella variicola H12 (abbreviated as K. variicola) was found to have Cr(VI) reduction ability. A high-efficiency Klebsiella variicola H12-carboxymethyl cellulose (abbreviated as CMC)-FeS@biochar system was established for Cr(VI) removal from aqueous solution. The Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM–EDS), X-ray photoelectron spectroscopy (XPS) results indicated that CMC-FeS was successfully loaded onto the surface of biochar, and K. variicola H12 grew well in the presence of CMC-FeS@biochar with microbial biomass up to 4.8 × 108 cells mL−1. Cr(VI) removal rate of CMC-FeS@biochar system, K. variicola H12 system and K. variicola H12 + CMC-FeS@biochar system were 61.8%, 82.2% and 96.6% respectively. This study demonstrated K. variicola H12-CMC-FeS@biochar system have potential value for efficient removal of Cr(VI) from Cr(VI)-polluted groundwater.


2018 ◽  
Vol 773 ◽  
pp. 373-378 ◽  
Author(s):  
Sujitra Onutai ◽  
Takaomi Kobayashi ◽  
Parjaree Thavorniti ◽  
Sirithan Jiemsirilers

This work aims to evaluate the effectiveness of fly ash based geopolymer powder as an adsorbent for heavy metals in aqueous solution. The structure of synthesized geopolymer was found to be highly amorphous due to the dissolution of fly ash phase. Moreover, the fly ash geopolymer powder has higher surface area compares to original fly ash with specific surface area of 85.01 m²/g and 0.83 m2/g, respectively. For this reason, the geopolymer powder has much higher removal efficiency compared to the original fly ash powder. The removal efficiency was affected by contact time, geopolymer amount, heavy metal initial concentration, pH, and temperature. The four heavy metals were chosen (Pb2+, Cu2+, Ni2+, Cd2+) for adsorption test. The highest heavy metal removal capacity was obtained at pH 5. The geopolymer powder adsorbed metal cations in the order of Pb2+>Cu2+>Cd2+>Ni2+. In addition, Langmuir model is more suitable for fly ash geopolymer powder adsorption of heavy metal ions in aqueous solution than Freundlich model. The results showed that the fly ash geopolymer powder has high efficiency for removal metal which could be employed excellent alternative for wastewater treatment.


2020 ◽  
pp. 15-20
Author(s):  
Ersin Yucel ◽  
Mine Yucel

In this study, the usage of the peppermint (Mentha piperita) for extracting the metal ions [Mg (II), Cr (II), Ni (II), Cu (II), Zn (II), Cd (II), Pb (II)] that exist at water was investigated. In order to analyze the stability properties, Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms were used at removing the metal ions and the highest correlation coefficients (R2) were obtained at Langmuir isotherm. Therefore, it is seen that the Langmuir model is more proper than the Freundlich model. However, it was found that the correlation coefficients of removing Ni and Cd is higher at Freundlich model than Langmuir and low at Dubinin-Radushkevich isotherm. It is established that the biosorption amount increase depends on the increase of biosorbent and it can be achieved high efficiency (95%) even with small amount (0.6 mg, peppermint extract) at lead ions. It is also determined that the peppermint extracted that is used at this study shows high biosorption capacity for metal ions and can be used for immobilization of metals from polluted areas.


RSC Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 953-959
Author(s):  
Chengguang Chen ◽  
Muqing Qiu

A biochar-supported nanoscale ferrous sulfide composite was prepared and applied for the treatment of Pb(ii) ions in aqueous solution.


2020 ◽  
Vol 37 ◽  
pp. 101339 ◽  
Author(s):  
Chengyu Duan ◽  
Tianyu Ma ◽  
Jianyu Wang ◽  
Yanbo Zhou

2012 ◽  
Vol 550-553 ◽  
pp. 2121-2124 ◽  
Author(s):  
Ling Ling Luo ◽  
Xing Xing Gu ◽  
Jun Wu ◽  
Shu Xian Zhong ◽  
Jian Rong Chen

Graphene for its unique physical structure, excellent mechanical, electrical and physical properties has been widely applied in nanoelectronics, microelectronics, energy storage material, composite materials and so on. In recent years, many researchers found graphene have outstanding adsorption capacity of contaminants in aqueous solution due to its high specific surface area. This paper summarized the graphene, graphene oxide and functionalized graphene removing various heavy metals in waste water.


2013 ◽  
Vol 789 ◽  
pp. 176-179 ◽  
Author(s):  
Eny Kusrini ◽  
Nofrijon Sofyan ◽  
Dwi Marta Nurjaya ◽  
Santoso Santoso ◽  
Dewi Tristantini

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.


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