scholarly journals Specifically Designed Magnetic Biochar From Waste Wood for Arsenic Removal

Author(s):  
Chih-Kuei Chen ◽  
Jia-Jia Chen ◽  
Nhat-Thien Nguyen ◽  
Thuy-Trang Le ◽  
Chang-Tang Chang

Abstract Arsenic is a kind of metal elements, widely distributed in nature. Many technologies, including adsorption, ion exchange, membrane separation and extraction, have been developed to treat arsenic-containing wastewater due to a series of drinking water safety problems caused by arsenic pollution. Biochar has some advantages of big surface area, low cost and so on. Therefore, waste wood was used as biochar, FeCl3·6H2O and KMnO4 were also used to promote the performance of arsenic removal. The results of XRD, BET, EA and VSM analysis show that modified biochar has major elements of Fe, Mn with KMnO4. The modified biochar (Fe1Mn1C1) has higher magnetism of 40 emu g-1. Through adsorption performance assessment, the best ratio of Fe/C is 1:1 and the adsorption efficiency and capacity of Fe1C1 is 61.6% and 0.681 mg g-1, respectively. Then, the best ratio of Mn, Fe and C is 4:1:1 with highest adsorption efficiency of 80.8% and capacity of 0.724 mg g-1. The best dosage of Fe1C1 and Fe1Mn2C1 is the same as 1 g L-1. It shows better adsorption capacity under higher pH with pristine biochar (PB) and Fe1C1 while under lower pH with Fe1Mn2C1. The adsorption patterns of PB and Fe1Mn2C1 fit Langmuir well. In contrast, adsorption pattern of Fe1C1 fits Freundlich well. In addition, three types of biochars all fit the pseudo second order adsorption kinetics.

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Chih-Kuei Chen ◽  
Jia-Jia Chen ◽  
Nhat-Thien Nguyen ◽  
Thuy-Trang Le ◽  
Nguyen-Cong Nguyen ◽  
...  

AbstractArsenic is a carcinogenic substance, with many cases of poisoning related to arsenic pollution in groundwater. In Taiwan arsenic in groundwater caused the notorious Blackfoot disease. Methods for arsenic removal from water include precipitation, membrane processes, ion exchange, and adsorption, but these processing technologies suffer from high investment costs and complex operations. The traditional adsorption method cannot be used for arsenic removal due to its high operating costs, difficulties in recovery, and low adsorption capacity. To address these issues, this study designed an adsorption material based on biochar for arsenic removal with higher adsorption properties and easy recovery. Biochar sources are readily available from waste wood as a cheap and environmentally friendly material. The efficiency of As (III) removal is also promoted by FeCl3 and KMnO4. The objectives of this research are to obtain optimum operation conditions by assessing the effects of different iron and manganese contents, different doses, different pH and different initial concentration. The adsorption mechanism between As (III) and biochar was studied by adsorption isotherms and the kinetic model. X-ray diffraction, energy-dispersive X-ray spectroscopy and elemental analyzer analysis results show that modified biochar has major elements of Fe and Mn. There is greater magnetism, 40 emu g− 1, in the modified biochar. The maximum adsorption efficiency of 81% and 0.72 mg g− 1 capacity occurs when the ratio of Mn, Fe and C is 4:1:1. The adsorption capacity is high under higher pH with pristine biochar and 1FeC under lower pH with 1Fe2MnC. The reaction mechanism is divided into four pathways. The first pathway is the attachment of As (III) ions into the pore of biochar via physical adsorption. In the second pathway, biochar can connect with As (III) through hydrogen bonding from the function group -OH in the biochar and the As (III) itself. In the third pathway, they can contact each other by electron force when the biochar surface is filled with a positive charge. In the fourth pathway, the compounds of manganese have strong oxidizability to oxidize As (III) to As(V). The iron ions then act as a bridge connecting the biochar and the As (III), resulting in the formation of new complex compounds.


2021 ◽  
Vol 14 ◽  
pp. 100585
Author(s):  
Amalia Lara Bursztyn Fuentes ◽  
Facundo Barraqué ◽  
Roberto Carlos Mercader ◽  
Alberto Néstor Scian ◽  
María Luciana Montes

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 426
Author(s):  
Yang Liu ◽  
Pengyun Yan ◽  
Feng Liu ◽  
Aoqun Jian ◽  
Shengbo Sang

Inspired by exceptional point (EP) sensing in non-Hermitian systems, in this work, a label-free biosensor for detecting low-concentration analytes is proposed, via a special multilayer structure: a resonant optical tunneling resonator. Due to the square root topology near the exceptional point, a recognized target analyte perturbs the system deviated from the exceptional point, leading to resolvable modes splitting in the transmission spectrum. The performance of the designed sensor is analyzed by the coupled-mode theory and transfer matrix method, separately. Here, the simulation results demonstrate that the obtained sensitivity is 17,120 nm/imaginary part unit of refractive index (IP) and the theoretical detection limit is 4.2 × 10−8 IP (regarding carcinoembryonic antigen (CEA), the minimum detection value is 1.78 ng). Instead of the typical diffusion manner, the liquid sample is loaded by convection, which can considerably improve the efficiency of sample capture and shorten the response time of the sensor. The sketched sensor may find potential application in the fields of biomedical detection, environment protection, and drinking water safety.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2682
Author(s):  
Gyuhyeon Kim ◽  
Young-Mo Kim ◽  
Su-Min Kim ◽  
Hyun-Uk Cho ◽  
Jong-Moon Park

In this study, magnetic steel slag biochar (MSSB) was synthesized from low-cost steel slag waste to investigate the effectiveness of steel slag biochar composite for NH4-N removal and magnetic properties in aqueous solution. The maximum adsorption capacity of NH4-N by MSSB was 4.366 mg/g according to the Langmuir model. The magnetic properties of MSSB indicated paramagnetic behavior and a saturation magnetic moment of 2.30 emu/g at 2 Tesla. The NH4-N adsorption process was well characterized by the pseudo-second order kinetic model and Temkin isotherm model. This study demonstrated the potential of magnetic biochar synthesized from steel slag waste for NH4-N removal in aqueous solution.


2014 ◽  
Vol 625 ◽  
pp. 889-892 ◽  
Author(s):  
Safoura Daneshfozoun ◽  
Bawadi Abdullah ◽  
Mohd Azmuddin Abdullah

This study developed an effective and economical physical pretreatment of OPEFB to be used as biosorbent for the removal of heavy metal ions such as Cu+2, Zn+2and Pb2+. The effects of fibres sizes, metal ions concentration (100-1000 ppm), initial pH (4-10) and contact time (20-150 min) were investigated in batch system. Samples were characterized with Atomic Absorption Spectrometry (AAS), Transmission Electron Microscopy (TEM) and Fourier Transmission Infra-red Spectroscopy (FTIR). Results showed pH-dependence adsorption efficiency and increased adsorption with initial metal concentrations where more than 92% adsorption efficiency achieved. We have successfully developed an eco-friendly, low cost adsorbent without any chemical modification or excessive energy disposal.


2013 ◽  
Vol 361-363 ◽  
pp. 674-681
Author(s):  
Wei Li

As more and more non-public fund entering rural drinking water safety engineering project market; it becomes very necessary to built rural drinking water safety engineering project guarantee mechanism. This paper proposes three steps of mechanism design. Firstly, history data is used to fit multivariate linear equation set up describing relationship between bank loss and key risk factors. Secondly, guarantee fee is calculated through model regression, which is threefold of possible bank loss. Thirdly, guarantee fee is adjusted according to variety of key risk factor in the process of project construction and operating.


2013 ◽  
Vol 49 (1) ◽  
pp. 5-9 ◽  
Author(s):  
D. C. Reid ◽  
K. Abramowski ◽  
A. Beier ◽  
A. Janzen ◽  
D. Lok ◽  
...  

Traditionally, the regulatory approach to maintaining the quality and safety of drinking water has largely been a prescriptive one based on the ability of any given supply to meet standards set for a number of different chemical and biological parameters. There are a number of issues around the assumptions and the limitations of a sampling and analysis regime. The basis for such regimes is essentially reactive rather than proactive and, consequently, the cause of the concern may already have impacted consumers before any effective action can be taken. Environment and Sustainable Resource Development has developed a template for recording drinking water safety plans together with guidance notes to help complete them. The template has been developed in MS-Excel and has been designed in a straightforward step-wise manner with guidance on the completion of each sheet. It includes four main risk tables covering each main element of water supply which are pre-populated with commonly found ‘generic’ risks and these are carefully assessed before considering what action is required to deal with significant risks. Following completion of the risk tables, key risks are identified and the interventions required to bring them into control.


2003 ◽  
Vol 47 (3) ◽  
pp. 7-14 ◽  
Author(s):  
S.E. Hrudey ◽  
P. Payment ◽  
P.M. Huck ◽  
R.W. Gillham ◽  
E.J. Hrudey

An estimated 2,300 people became seriously ill and seven died from exposure to microbially contaminated drinking water in the town of Walkerton, Ontario, Canada in May 2000. The severity of this drinking water disaster resulted in the Government of Ontario calling a public inquiry by Mr. Justice Dennis O’Connor to address the cause of the outbreak, the role (if any) of government policies in contributing to this outbreak and, ultimately, the implications of this experience on the safety of drinking water across the Province of Ontario. The circumstances surrounding the Walkerton tragedy are an important reference source for those concerned with providing safe drinking water. Although some circumstances are obviously specific to this epidemic, others are uncomfortably reminiscent of waterborne outbreaks that have occurred elsewhere. These recurring themes suggested the need for attention to broad issues of drinking water security and they present the challenge for how drinking water safety can be managed to prevent such tragedies in the future.


2019 ◽  
Vol 654 ◽  
pp. 1132-1145 ◽  
Author(s):  
Lucas Rocha-Melogno ◽  
Rebecca Yoo ◽  
Osvaldo Broesicke ◽  
Achilles Kallergis ◽  
José Garcia ◽  
...  

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