Super adsorbent - based remediation and on-site flow injection analysis determeniation of arsenic ions in gold mining site

Arsenic is a mineral which is abundant in gold mining sites. It is a toxic substance which needs to be removed. Thus, this research investigated the problem of extremely high arsenic (As) concentration in effluent (water and slurry) from Selinsing gold mine site, Pahang, Malaysia and developed an ef...

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Main Author:	Asmel, Nabel Kalel
Format:	Thesis
Language:	English
Published:	2017
Subjects:	TA Engineering (General) Civil engineering (General)
Online Access:	http://eprints.utm.my/id/eprint/79416/1/NabelKalelAsmelPFKA2017.pdf
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spelling	my-utm-ep.794162018-10-16T07:30:38Z Super adsorbent - based remediation and on-site flow injection analysis determeniation of arsenic ions in gold mining site 2017 Asmel, Nabel Kalel TA Engineering (General). Civil engineering (General) Arsenic is a mineral which is abundant in gold mining sites. It is a toxic substance which needs to be removed. Thus, this research investigated the problem of extremely high arsenic (As) concentration in effluent (water and slurry) from Selinsing gold mine site, Pahang, Malaysia and developed an effective operational remedial method using an adsorbent material (Ecomel). In this research, a new method for measuring As(III) and As(V), which exist in the contaminated soil and liquid effluents was developed using flow injection analysis (FIA) system, while the total As was analyzed using atomic fluorescence spectrometry (AFS) for the remediating samples. By using the FIA method, the As speciation detection limit of (S/N = 3) for both As(III) and As(V) were found to be 5 μg/L with standard deviation 2.2 (n = 20). It also showed a wide dynamic range coefficient of detection (R2) of 0.999 for As(III) and 0.9989 for As(V). This portable analytical method was successfully applied for the determination of As speciation in the effluent collected from Selinsing gold mine site without further treatment. For the characterizations of slurry and adsorbent materials (Ecomel), X-ray diffraction (XRD), X-ray fluorescence (XRF), energy-dispersive X-ray spectroscopy (EDX), Field Emission Scanning Electron Microscopy (FESEM), Focus Ion Beam–Scanning Electron Microscope (FIB-SEM), Inductively Coupled Plasma Optical Emission Spectrophotometer (ICPOES), Elemental Analyzer (EA) and Brunauer–Emmett– Teller (BET) were used. In the case of liquid effluent from the tailing dam, the pH and cyanide concentrations were measured at 11.5 and 204 mg/L, respectively. However, the batch experiments clearly proved that As leaching from the slurry (contact time: 24 h, stirring speed: 200 rpm, and S:L ratio 1:5) was extremely higher at pH 11.5 compared to pH 2.5 and were measured to be 8,720 and 1,010 μg/L, respectively. The major contributors to the exceedingly elevated levels of As concentration in liquid effluents were attributed to alkaline pH, high cyanide and silicate concentration, as well as high oxidation environment. The batch experiments on Ecomel revealed that maximum adsorption capacity determined at initial pH 2.5 from the Langmuir-Freundlich isotherm model was found to be 704.7 and 122.7 mg/g for As(III) and As(V), respectively. These results indicated that Ecomel has high adsorbent efficiency, cost-effective and is suitable for in-situ and ex-situ remediation of highly concentrated As(III) and As(V) toxicants in aqueous solutions. For As standard solution with initial pH 2.5 and concentration of As at 1 mg/L, it was observed that 0.3125 g/L of Ecomel with 2 h contact time can adequately remove 97.0% of As(V) and 98.1% of As(III), respectively. As a conclusion, results from AFS showed that the treatment of As using Ecomel at initial pH 2.5 was the most proficient for remediation of liquid effluent and slurry. 2017 Thesis http://eprints.utm.my/id/eprint/79416/ http://eprints.utm.my/id/eprint/79416/1/NabelKalelAsmelPFKA2017.pdf application/pdf en public phd doctoral Universiti Teknologi Malaysia, Faculty of Civil Engineering Faculty of Civil Engineering
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	TA Engineering (General) Civil engineering (General)
spellingShingle	TA Engineering (General) Civil engineering (General) Asmel, Nabel Kalel Super adsorbent - based remediation and on-site flow injection analysis determeniation of arsenic ions in gold mining site
description	Arsenic is a mineral which is abundant in gold mining sites. It is a toxic substance which needs to be removed. Thus, this research investigated the problem of extremely high arsenic (As) concentration in effluent (water and slurry) from Selinsing gold mine site, Pahang, Malaysia and developed an effective operational remedial method using an adsorbent material (Ecomel). In this research, a new method for measuring As(III) and As(V), which exist in the contaminated soil and liquid effluents was developed using flow injection analysis (FIA) system, while the total As was analyzed using atomic fluorescence spectrometry (AFS) for the remediating samples. By using the FIA method, the As speciation detection limit of (S/N = 3) for both As(III) and As(V) were found to be 5 μg/L with standard deviation 2.2 (n = 20). It also showed a wide dynamic range coefficient of detection (R2) of 0.999 for As(III) and 0.9989 for As(V). This portable analytical method was successfully applied for the determination of As speciation in the effluent collected from Selinsing gold mine site without further treatment. For the characterizations of slurry and adsorbent materials (Ecomel), X-ray diffraction (XRD), X-ray fluorescence (XRF), energy-dispersive X-ray spectroscopy (EDX), Field Emission Scanning Electron Microscopy (FESEM), Focus Ion Beam–Scanning Electron Microscope (FIB-SEM), Inductively Coupled Plasma Optical Emission Spectrophotometer (ICPOES), Elemental Analyzer (EA) and Brunauer–Emmett– Teller (BET) were used. In the case of liquid effluent from the tailing dam, the pH and cyanide concentrations were measured at 11.5 and 204 mg/L, respectively. However, the batch experiments clearly proved that As leaching from the slurry (contact time: 24 h, stirring speed: 200 rpm, and S:L ratio 1:5) was extremely higher at pH 11.5 compared to pH 2.5 and were measured to be 8,720 and 1,010 μg/L, respectively. The major contributors to the exceedingly elevated levels of As concentration in liquid effluents were attributed to alkaline pH, high cyanide and silicate concentration, as well as high oxidation environment. The batch experiments on Ecomel revealed that maximum adsorption capacity determined at initial pH 2.5 from the Langmuir-Freundlich isotherm model was found to be 704.7 and 122.7 mg/g for As(III) and As(V), respectively. These results indicated that Ecomel has high adsorbent efficiency, cost-effective and is suitable for in-situ and ex-situ remediation of highly concentrated As(III) and As(V) toxicants in aqueous solutions. For As standard solution with initial pH 2.5 and concentration of As at 1 mg/L, it was observed that 0.3125 g/L of Ecomel with 2 h contact time can adequately remove 97.0% of As(V) and 98.1% of As(III), respectively. As a conclusion, results from AFS showed that the treatment of As using Ecomel at initial pH 2.5 was the most proficient for remediation of liquid effluent and slurry.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Asmel, Nabel Kalel
author_facet	Asmel, Nabel Kalel
author_sort	Asmel, Nabel Kalel
title	Super adsorbent - based remediation and on-site flow injection analysis determeniation of arsenic ions in gold mining site
title_short	Super adsorbent - based remediation and on-site flow injection analysis determeniation of arsenic ions in gold mining site
title_full	Super adsorbent - based remediation and on-site flow injection analysis determeniation of arsenic ions in gold mining site
title_fullStr	Super adsorbent - based remediation and on-site flow injection analysis determeniation of arsenic ions in gold mining site
title_full_unstemmed	Super adsorbent - based remediation and on-site flow injection analysis determeniation of arsenic ions in gold mining site
title_sort	super adsorbent - based remediation and on-site flow injection analysis determeniation of arsenic ions in gold mining site
granting_institution	Universiti Teknologi Malaysia, Faculty of Civil Engineering
granting_department	Faculty of Civil Engineering
publishDate	2017
url	http://eprints.utm.my/id/eprint/79416/1/NabelKalelAsmelPFKA2017.pdf
_version_	1747818222070005760

Super adsorbent - based remediation and on-site flow injection analysis determeniation of arsenic ions in gold mining site

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