Arsenic (III) Removal from Aqueous Water by Indigenous Iron Ore Adsorbent from Balochistan Province of Pakistan

Zulfiqar Ali Bhatti

doi:10.22581/muet1982.2101.02

Abstract

The work focuses on the removal of Arsenic-III (As(III)) from water sample by an indigenous iron ore from Balochistan by adsorption method. Three iron ore samples were analyzed by X-Ray Diffractometer (XRD) and a sample from Shikarap containing iron 36.2% was selected because it contained the highest amount of hematite. The batch study was conducted to examine the adsorption by iron ore and maximum adsorption was observed at pH 6, 1/2 g dose per 50 mL solution, contact time 2 hr and shaking speed 150 rpm. At the optimized conditions, the removal was 89% when monitored at 50μg L-1 initial concentration of arsenic. The arsenic removal was monitored by Atomic Absorption Spectrometer (AAS) using hydride generation. Dubinin - Radushkevich (D-R), Freundlich and Langmuir's isotherms were examined. The highest adsorption capacityof iron ore for As(III) removal was observed 13.67 μg g-1 by Langmuir model and Freundlich isotherm indicated good adsorption intensity with value n = 1.512. Thermodynamic parameters revealed that adsorption was exothermic and physisorption. The Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray (EDX)techniques were applied to scan the surface morphology and the percentage elemental composition of samples respectively. SEM results demonstrated that Shikarap mineral grains are an oval shape and these were changed after the uptake of As(III). The EDX spectra of Shikarap mineral confirm the As(III) adsorption on particles as As 4.19%.

Highlights

Elements that have an atomic weight between 63.5-200.6 and possess density greater than 5 g/m3 are basically described as heavy metals [1,2]
The iron ore samples from Balochistan were provided by the Pakistan Geological Survey, from five different locations of province Balochistan which include Quetta, Shikarap, Hoshi, Chagi, Qalat, and Dilband
In this work indigenous Shikarap iron ore was effectively used for the removal of As(III) from water by the batch adsorption method

Summary

Introduction

Elements that have an atomic weight between 63.5-200.6 and possess density greater than 5 g/m3 are basically described as heavy metals [1,2]. Zinc, manganese, iron, cobalt, are some of the examples of heavy metals and effect on the biochemical processes occurring in the human body. The excessive exposure of the human body with these heavy metal results in hazardous conditions. The other toxic heavy metals include chromium, mercury, lead, cadmium, and arsenic. The concentration of toxic heavy metals even in parts per billion is nondegradable, accumulates in the human body and produce severe health problems [3]. The common techniques applied for the sequestration of heavy metals from water include adsorption, precipitation, ion exchange, membrane separation, coagulation, and flocculation. Fu et al [4], Hua et al [5] and Barkat et al [6], focused on adsorption process for the

Methods

Results

Conclusion