Arsenic removal by natural and chemically modified water melon rind in aqueous solutions and groundwater

Shakoor, Muhammad Bilal,Niazi, Nabeel Khan,Bibi, Irshad,Shahid, Muhammad,Sharif, Fakhra,Bashir, Safdar,Shaheen, Sabry M.,Wang, Hailong,Tsang, Daniel C.W.,Ok, Yong Sik,Rinklebe, Jö,rg Elsevier 2018 The Science of the total environment Vol.645 No.-

<P><B>Abstract</B></P> <P>Contamination of groundwater with toxic arsenic (As) has become an emerging health and environmental problem around the world, which has seen significant attention amongst the scientists for development of new sorbents to remediate As-contaminated water. Here, we explored the arsenate (As(V)) and arsenite (As(III)) sorption to natural water melon rind (WMR), xanthated WMR and citric acid-modified WMR in aqueous solutions, and determined potential of the most potent sorbent for As removal in groundwater. Xanthated WMR (X-WMR) showed relatively higher As(V) and As(III) removal than the citric acid modified WMR (CA-WMR) and natural WMR. The maximum As(III) (99%) and As(V) (98%) removal was obtained at pH 8.2 and 4.6, respectively, by X-WMR at 4 mg L<SUP>−1</SUP> initial As(V) and As(III) concentrations and sorbent dose of 1 g L<SUP>−1</SUP>. Langmuir isotherm model best fitted (<I>R</I> <SUP> <I>2</I> </SUP> of up to 0.96) the data both for As(III) and As(V) sorption to X-WMR. Sorption kinetics of As(V) and As(III) was well described (<I>R</I> <SUP> <I>2</I> </SUP> of up to 0.99) by the pseudo second-order model on surface of the X-WMR. Thermodynamic investigations revealed that As(V) and As(III) sorption was endothermic and spontaneous. The FTIR spectroscopy depicted the presence of different surface function groups (OH, COOH, S-bearing (C=S, S=O and S–S)) which were involved in As(V) and As(III) sequestration on the sorbents examined here. Significantly, X-WMR showed (up to 49%) greater As(III) and As(V) sorption than that of natural WMR. Our results demonstrated that X-WMR efficiently removed 94%–100% (<I>n</I> = 16) of As from As-contaminated drinking well water which possessed detectable concentrations of some anions (e.g., SO<SUB>4</SUB>, CO<SUB>3</SUB>, HCO<SUB>3</SUB>). This study highlights that the X-WMR has potential to remove As, notably As(III), from solutions and drinking water, and might be utilized as a reactive medium for the treatment of As-contaminated water.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Water melon rind (WMR) was tested for arsenic removal potential from water. </LI> <LI> Xanthated WMR removed up to 99% of As(III)/As(V) in solutions. </LI> <LI> Langmuir and pseudo second-order models provided the best fits for As(III) and As(V). </LI> <LI> FTIR spectra showed arsenic sequestration with surface functional groups of sorbents. </LI> <LI> Xanthated WMR successfully removed 94–100% arsenic from drinking well water. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Human health implications, risk assessment and remediation of As-contaminated water: A critical review

Shakoor, Muhammad Bilal,Nawaz, Rab,Hussain, Fida,Raza, Maimoona,Ali, Shafaqat,Rizwan, Muhammad,Oh, Sang-Eun,Ahmad, Sajjad Elsevier 2017 Science of the Total Environment Vol.601 No.-

<P><B>Abstract</B></P> <P>Arsenic (As) is a naturally occurring metalloid and Class-A human carcinogen. Exposure to As via direct intake of As-contaminated water or ingestion of As-contaminated edible crops is considered a life threatening problem around the globe. Arsenic-laced drinking water has affected the lives of over 200 million people in 105 countries worldwide. Limited data are available on various health risk assessment models/frameworks used to predict carcinogenic and non-carcinogenic health effects caused by As-contaminated water. Therefore, this discussion highlights the need for future research focusing on human health risk assessment of individual As species (both organic and inorganic) present in As-contaminated water. Various conventional and latest technologies for remediation of As-contaminated water are also reviewed along with a discussion of the fate of As-loaded waste and sludge.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Arsenic is recognized as a Class-A human carcinogen. </LI> <LI> Groundwater As contamination has affected over 200 million people worldwide. </LI> <LI> This paper reviews current knowledge regarding As in the environment. </LI> <LI> A critical assessment of remediation of contaminated water is presented. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Remediation of arsenic-contaminated water using agricultural wastes as biosorbents

Shakoor, Muhammad Bilal,Niazi, Nabeel Khan,Bibi, Irshad,Murtaza, Ghulam,Kunhikrishnan, Anitha,Seshadri, Balaji,Shahid, Muhammad,Ali, Shafaqat,Bolan, Nanthi S.,Ok, Yong Sik,Abid, Muhammad,Ali, Fawad Informa UK (TaylorFrancis) 2016 Critical reviews in environmental science and tech Vol.46 No.5

<P>Arsenic (As) contamination of groundwater reservoirs is a global environmental and health issue given to its toxic and carcinogenic nature. Over 170 million people have been affected by As due to the ingestion of As-contaminated groundwater. Conventional methods such as reverse osmosis, ion exchange, and electrodialysis are commonly used for the remediation of As-contaminated water; however, the high cost and sludge production put limitations on their application to remove As from water. This review critically addresses the use of various agricultural waste materials (e.g., sugarcane bagasse, peels of various fruits, wheat straw) as biosorbents, thereby offering an eco-friendly and low-cost solution for the removal of As from contaminated water supplies. The effect of solution chemistry such as solution pH, cations, anions, organic ligands, and various other factors (e.g., temperature, contact time, sorbent dose) on As biosorption, and safe disposal methods for As-loaded biosorbents to reduce secondary As contamination are also discussed.</P>

Groundwater status in Pakistan: A review of contamination, health risks, and potential needs

Raza, Maimoona,Hussain, Fida,Lee, Jin-Yong,Shakoor, Muhammad Bilal,Kwon, Kideok D. Informa UK (TaylorFrancis) 2017 Critical reviews in environmental science and tech Vol.47 No.18

<P>We examined the current groundwater (used for drinking) quality in Pakistan after implementation of Millennium Development Goals, including contaminants, their sources, and relevant health impacts. The drinking water quality parameters of most of the reported results exceeded the guidelines suggested by the World Health Organization (WHO) and National Environmental Quality Standards (NEQS). Natural sources of groundwater contamination have been activated due to anthropogenic activities like mining, and open dumping of industrial and domestic wastes which lead to poor groundwater quality. Globally, 780 million people, and 100 million people in Pakistan are exposed to unsafe water sources. Therefore, this review demonstrates the potential needs to achieve the safe drinking water goal of the Agenda 2030. The development of a proper monitoring network, installation of treatment plants, and implementation of legislations are recommended in this review.</P>

Phenol removal and hydrogen production from water: Silver nanoparticles decorated on polyaniline wrapped zinc oxide nanorods

Asim Jilani,Mohammad Omaish Ansari,Ghani ur Rehman,Muhammad Bilal Shakoor,Syed Zajif Hussain,Mohd Hafiz Dzarfan Othman,Sajid Rashid Ahmad,Mohsin Raza Dustgeer,Ahmed Alshahrie 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.109 No.-

The toxic and carcinogenic organic compounds discharge from industries, contaminate the natural reservoirsof water and air which eventually pose a global threat not only to the aquatic life but also to thehumanity. Herein, ternary nanocomposites of silver-nanoparticle (AgNPs)-decorated on polyaniline(Pani)-wrapped zinc oxide nanorods (AgNPs@Pani/ZnO) were prepared via a facile approach. Thenanocomposite degraded 97.91% phenol with an optimized dosage and concentration of H2O2. Moreover, the apparent rate constant for phenol degradation was 3.69 times higher than for pure ZnOnanorods. The hydrogen production from AgNPs@Pani/ZnO was 1.58 and 2.74 times higher than Pani/ZnO and ZnO, respectively. The enhanced phenol degradation and hydrogen production is attributed tothe transfer of holes to the Pani, from which the electrons were transferred to the conduction band ofZnO and eventually to the conduction band of the AgNPs, where they accelerated the redox reactionsfor rapid photolysis of water and phenol. The concentration of the catalyst dosage affected the rate ofphenol degradation. Further, response surface methodology was also applied in order to design 13 setsof random experiments in which the catalyst dosage and degradation time were varied to predict thephenol degradation.