This page has only limited features, please log in for full access.
Antimony (Sb) is a regulated pollutant that is frequently present at elevated concentrations in natural bodies of water due to natural sources and human activities. Therefore, its purification from fresh water streams is of ultimate importance. This study focused on the iron hydroxide (FHO) formation and removal of Sb ions from water via ferric chloride (FC) coagulation. The effects of pH, contact time, concentration, temperature, and ionic strength (IS) were studied to explore the mechanistic insights into the removal behavior of both Sb ions during potable water purification. Results indicated that the solubility of FHO decrease by increasing the pH, thus repulsing the oxyanions at alkaline pH, decreasing in turn the adsorption capacity of Sb(V) species. The influence of contact time and equilibrium Sb concentration on FHO formation was found to be insignificant. The adsorption of Sb on FHO was well fitted with Pseudo-first order and Langmuir-Freundlich (L–F) models. Physical adsorption of Sb ions onto FHO was identified to be the major mechanism using the Dubinin-Radushkevich (D–R) isotherm model. Thermodynamic parameters (ΔG, ΔH, and ΔS) suggested that the Sb adsorption process was spontaneously exothermic with increased randomness. A more pronounced effect of IS on high Sb feed was observed with increasing sorption affinities upon enhancing electrolyte concentration. The mechanism was further supported by X-ray diffraction spectroscopy, which revealed the likelihood of inner-sphere complexation and physisorption of Sb onto FHO. Moreover, an involvement of coprecipitation phenomena during growing FHO was observed as key phenomena for greater Sb(III) removal. In general, the results of current research may provide detailed insights into the adsorption ability of FHO and the potential mechanisms responsible for the removal of Sb ions during potable water treatment.
Muhammad Ali Inam; Rizwan Khan; Ick Tae Yeom. Kinetic and isothermal sorption of antimony oxyanions onto iron hydroxide during water treatment by coagulation process. Journal of Water Process Engineering 2021, 41, 102050 .
AMA StyleMuhammad Ali Inam, Rizwan Khan, Ick Tae Yeom. Kinetic and isothermal sorption of antimony oxyanions onto iron hydroxide during water treatment by coagulation process. Journal of Water Process Engineering. 2021; 41 ():102050.
Chicago/Turabian StyleMuhammad Ali Inam; Rizwan Khan; Ick Tae Yeom. 2021. "Kinetic and isothermal sorption of antimony oxyanions onto iron hydroxide during water treatment by coagulation process." Journal of Water Process Engineering 41, no. : 102050.
Coprecipitation-adsorption plays a significant role during coagulation-flocculation-sedimentation (C/F/S) of antimony (Sb) in water. This work uses a Box–Behnken statistical experiment design (BBD) and response surface methodology (RSM) to investigate the effects of major operating variables such as initial Sb(III, V) concentration (100–1000 µg/L), ferric chloride (FC) dose (5–50 mg/L), and pH (4–10) on redox Sb species. Experimental data of Sb(III, V) removal were used to determine response function coefficients. The model response value (Sb removal) showed good agreement with the experimental results. FC showed promising coagulation behavior of both Sb species under optimum pH (6.5–7.5) due to its high affinity towards Sb species and low residual Fe concentration. However, a high dose of 50 mg/L of FC is required for the maximum (88–93%) removal of Sb(V), but also for the highest (92–98%) removal of low initial concentrations of Sb(III). Furthermore, BBD and RSM were found to be reliable and feasible for determining the optimum conditions for Sb removal from environmental water samples by a C/F/S process. This work may contribute to a better understanding and prediction of the C/F/S behavior of Sb(III, V) species in aqueous environments, to reduce potential risks to humans.
Muhammad Ali Inam; Rizwan Khan; Ick Tae Yeom; Abdul Salam Buller; Muhammad Akram; Muhammad Waleed Inam. Optimization of Antimony Removal by Coagulation-Flocculation-Sedimentation Process Using Response Surface Methodology. Processes 2021, 9, 117 .
AMA StyleMuhammad Ali Inam, Rizwan Khan, Ick Tae Yeom, Abdul Salam Buller, Muhammad Akram, Muhammad Waleed Inam. Optimization of Antimony Removal by Coagulation-Flocculation-Sedimentation Process Using Response Surface Methodology. Processes. 2021; 9 (1):117.
Chicago/Turabian StyleMuhammad Ali Inam; Rizwan Khan; Ick Tae Yeom; Abdul Salam Buller; Muhammad Akram; Muhammad Waleed Inam. 2021. "Optimization of Antimony Removal by Coagulation-Flocculation-Sedimentation Process Using Response Surface Methodology." Processes 9, no. 1: 117.
The low phosphate content in the surface water is considered a pollutant that promotes algae reproduction and leads to eutrophication. Bimetallic Fe/La nanoparticles doped on pomegranate fiber (Fe/La Peel) were fabricated by solvothermal synthesis method and applied as biosorbent for phosphate removal in this study. Fe–La/Peel had an irregular and rough surface with a specific surface area of 93.18 m2/g and its surface was uniformly covered with Fe and La, providing potential adsorption sites for phosphate uptake. At the pH 2.91, the highest capacity of Fe/Peel, La/Peel and Fe–La/Peel were 13.91 mg/g, 38.86 mg/g and 44.5 mg/g, respectively. Batch adsorption experiments indicated that Fe–La/Peel biosorbent had excellent adsorption ability. In batch adsorption experiment, highest adsorption capacities of Fe–La/Peel fitted by Langmuir and Sips isotherms were 75.09 mg/g and 78.99 mg/g at 323 K, respectively. The total lowest metal leaching of Fe/La Peel was found 0.054 μg/mL under alkali condition, and the highest metal leaching was determined 8.13 μg/mL under acidic condition. The adsorption performance of Fe/La Peel was better than those La/Peel and Fe/Peel at the same pH levels. Phosphate capture by Fe–La/Peel bio-nanocomposite was a homogeneous adsorption process and increased capacity with the rising temperature. At neutral pH, phosphate uptake by Fe–La/Peel could maintain high efficiency and metal leaching was almost negligible. The preferential phosphate adsorption by Fe–La/Peel can also be achieved in the same magnitudes of coexisting anions (Cl−, NO3−, HCO3−). And the adsorption capacity was reduced to less than 20% in the presence of electrolytes. These results showed that Fe–La/Peel has the potential to be used for environmental remediation to remove phosphate from the wastewater.
Muhammad Akram; Xing Xu; Baoyu Gao; Shue Wang; Rizwan Khan; Qinyan Yue; Pijun Duan; Hongbing Dan; Jingwen Pan. Highly efficient removal of phosphate from aqueous media by pomegranate peel co-doping with ferric chloride and lanthanum hydroxide nanoparticles. Journal of Cleaner Production 2020, 292, 125311 .
AMA StyleMuhammad Akram, Xing Xu, Baoyu Gao, Shue Wang, Rizwan Khan, Qinyan Yue, Pijun Duan, Hongbing Dan, Jingwen Pan. Highly efficient removal of phosphate from aqueous media by pomegranate peel co-doping with ferric chloride and lanthanum hydroxide nanoparticles. Journal of Cleaner Production. 2020; 292 ():125311.
Chicago/Turabian StyleMuhammad Akram; Xing Xu; Baoyu Gao; Shue Wang; Rizwan Khan; Qinyan Yue; Pijun Duan; Hongbing Dan; Jingwen Pan. 2020. "Highly efficient removal of phosphate from aqueous media by pomegranate peel co-doping with ferric chloride and lanthanum hydroxide nanoparticles." Journal of Cleaner Production 292, no. : 125311.
Engineered nanomaterials (ENMs), such as copper oxide nanoparticles (CuO NPs), are emerging as pollutants extensively used in many commercial and industrial applications, thus raising environmental concerns due to their release into water bodies. It is, therefore, essential to remove these pollutants from water bodies in order to minimize the potential threat to the aquatic environment and human health. The objective of this study was to investigate the removal of CuO NPs from waters by the coagulation process. This study also explored the efficiency of coagulation to remove hydrophobic/hydrophilic dissolved organic matter (DOM) and turbidity with varying polyaluminum chloride (PACl) doses. According to the results, a high concentration of DOM affects both the CuO NPs zeta potential and hydrodynamic diameter, thereby decreasing the agglomeration behavior. At effective coagulation zone (ECR), high removal of CuO NPs (>95%) was observed for all studied waters (hydrophobic and hydrophilic waters), above ECR excess charge induced by coagulant restabilized particles in solution. Furthermore, waters containing hydrophobic DOM and those with high UV254nm values needed more coagulant dose than hydrophilic waters to obtain similar CuO NP removals. The primary mechanism involved in CuO NPs removal might be charge neutralization. These findings suggest that PACl is an effective coagulant in the removal of CuO NPs; however, water characteristics are an influencing factor on the removal performance of ENMs during the coagulation process.
Rizwan Khan; Muhammad Ali Inam; Muhammad Akram; Ahmed Uddin; Sarfaraz Khan; Ick Tae Yeom. Effect of Dissolved Organic Matter on Agglomeration and Removal of CuO Nanoparticles by Coagulation. Processes 2019, 7, 455 .
AMA StyleRizwan Khan, Muhammad Ali Inam, Muhammad Akram, Ahmed Uddin, Sarfaraz Khan, Ick Tae Yeom. Effect of Dissolved Organic Matter on Agglomeration and Removal of CuO Nanoparticles by Coagulation. Processes. 2019; 7 (7):455.
Chicago/Turabian StyleRizwan Khan; Muhammad Ali Inam; Muhammad Akram; Ahmed Uddin; Sarfaraz Khan; Ick Tae Yeom. 2019. "Effect of Dissolved Organic Matter on Agglomeration and Removal of CuO Nanoparticles by Coagulation." Processes 7, no. 7: 455.
The process of coagulation and precipitation affect the fate and mobility of antimony (Sb) species in drinking water. Moreover, the solubility and physico-chemical properties of the precipitates may be affected by the media chemistry. Accordingly, the present study aimed to investigate the removal of Sb(III, V) species by ferric chloride coagulation under various water chemistry influences with a particular focus on the role of the properties of the precipitates. The results indicated that the amount of Sb(III) removed increased with increasing solution pH, showing the insignificant effects of the hydrodynamic diameter (HDD) and ζ-potential of the precipitates. However, no Sb(V) removal occurred at alkaline pH values, while a highly negative ζ-potential and the complete dissolution of precipitates were observed in the aqueous solution. The solution pH was also useful in determining the dominant coagulation mechanisms, such as co-precipitation and adsorption. The Fe solubility substantially affects the Sb removal at a certain pH range, while the HDD of the precipitates plays an insignificant role in Sb removal. The presence of divalent cations brings the ζ-potential of the precipitates close to point of zero charge (pzc), thus enhancing the Sb(V) removal at alkaline pH conditions. Pronounced adverse effects of humic acid were observed on Sb removal, ζ-potential and HDD of the precipitates. In general, this study may provide critical information to a wide group of researchers dealing with environmental protection from heavy metal pollution.
Muhammad Ali Inam; Rizwan Khan; Muhammad Akram; Sarfaraz Khan; Ick Tae Yeom. Effect of Water Chemistry on Antimony Removal by Chemical Coagulation: Implications of ζ-Potential and Size of Precipitates. International Journal of Molecular Sciences 2019, 20, 2945 .
AMA StyleMuhammad Ali Inam, Rizwan Khan, Muhammad Akram, Sarfaraz Khan, Ick Tae Yeom. Effect of Water Chemistry on Antimony Removal by Chemical Coagulation: Implications of ζ-Potential and Size of Precipitates. International Journal of Molecular Sciences. 2019; 20 (12):2945.
Chicago/Turabian StyleMuhammad Ali Inam; Rizwan Khan; Muhammad Akram; Sarfaraz Khan; Ick Tae Yeom. 2019. "Effect of Water Chemistry on Antimony Removal by Chemical Coagulation: Implications of ζ-Potential and Size of Precipitates." International Journal of Molecular Sciences 20, no. 12: 2945.
The increased use of copper oxide nanoparticles (CuO NPs) in commercial products and industrial applications raises concerns about their adverse effects on aquatic life and human health. Therefore, the current study explored the removal of CuO NPs from water via coagulation by measuring solubility under various pH values and humic acid (HA) concentrations. The results showed that the media pH significantly affected the coagulation efficiency of CuO NPs (30 mg/L) under various (0–0.30 mM) ferric chloride (FC) dosages. The concentration of dissolved Cu2+ ions at pH 3–6 was (16.5–4.8 mg/L), which was higher than at other studied pH (7–11). Moreover, the simultaneous effect of coagulants and charge neutralization at pH 6–8 enhanced the removal of CuO NPs. At a lower FC (0–0.05 mM) dosage, the higher HA concentration inhibited the aggregation of CuO NPs. However, at the optimum dose of (0.2 mM) FC, the efficiency of turbidity removal and solubility of CuO NPs between pH 8 and 11 was above 98% and 5%, respectively, probably due to coagulant enmeshment. Our study suggested that coagulation was effective in removing the CuO NPs from the complex matrices with pH values ranging from 8–11. The findings of the present study provide insight into the coagulation and dissolution behavior of CuO NPs during the water treatment process.
Rizwan Khan; Muhammad Ali Inam; Saba Zam Zam; Muhammad Akram; SooKyo Shin; Ick Tae Yeom. Coagulation and Dissolution of CuO Nanoparticles in the Presence of Dissolved Organic Matter Under Different pH Values. Sustainability 2019, 11, 2825 .
AMA StyleRizwan Khan, Muhammad Ali Inam, Saba Zam Zam, Muhammad Akram, SooKyo Shin, Ick Tae Yeom. Coagulation and Dissolution of CuO Nanoparticles in the Presence of Dissolved Organic Matter Under Different pH Values. Sustainability. 2019; 11 (10):2825.
Chicago/Turabian StyleRizwan Khan; Muhammad Ali Inam; Saba Zam Zam; Muhammad Akram; SooKyo Shin; Ick Tae Yeom. 2019. "Coagulation and Dissolution of CuO Nanoparticles in the Presence of Dissolved Organic Matter Under Different pH Values." Sustainability 11, no. 10: 2825.
The co-occurrence of arsenic (As) and organic ligands in water bodies has raised environmental concerns due to their toxicity and adverse effects on human health. The present study aims to elucidate the influences of hydrophobic/hydrophilic organic ligands, such as humic acid (HA) and salicylic acid (SA), on the interactive behavior of As species in water. Moreover, the competitive removal behaviors of As(III, V) species and total organic carbon (TOC) were systematically investigated by coagulation-flocculation-sedimentation (C/F/S) under various aqueous matrices. The results showed the stronger binding affinity of As(V) than As(III) species, with a higher complexation ability of hydrophobic ligands than hydrophilic. The media containing hydrophilic ligands require smaller ferric chloride (FC) doses to achieve the higher As(III, V) removal, while the optimum FC dose required for As(III) removal was found to be higher than that for As(V). Moreover, hydrophobic ligands showed higher TOC removal than hydrophilic ligands. The pronounced adverse effect of a higher concentration of hydrophobic ligands on the removal efficiencies of As(V) and TOC was observed. The adsorption of As(V) on Fe precipitates was better fitted with the Langmuir model but the Freundlich isotherm was more suitable for As(III) in the presence of hydrophilic SA. Moreover, TOC removal was substantially decreased in the As(V) system as compared to the As(III) system due to the dissolution of Fe precipitates at higher As(V) concentrations. The results of FC composite flocs demonstrated that the combined effect of oxidation, charge neutralization and adsorption played an important role in the removal of both toxicants during the C/F/S process. In summary, the findings of the present study provide insights into the fate, mobility and competitive removal behavior of As(III, V) species and organic ligands in the water treatment process.
Muhammad Ali Inam; Rizwan Khan; Muhammad Akram; Sarfaraz Khan; Du Ri Park; Ick Tae Yeom. Interaction of Arsenic Species with Organic Ligands: Competitive Removal from Water by Coagulation-Flocculation-Sedimentation (C/F/S). Molecules 2019, 24, 1619 .
AMA StyleMuhammad Ali Inam, Rizwan Khan, Muhammad Akram, Sarfaraz Khan, Du Ri Park, Ick Tae Yeom. Interaction of Arsenic Species with Organic Ligands: Competitive Removal from Water by Coagulation-Flocculation-Sedimentation (C/F/S). Molecules. 2019; 24 (8):1619.
Chicago/Turabian StyleMuhammad Ali Inam; Rizwan Khan; Muhammad Akram; Sarfaraz Khan; Du Ri Park; Ick Tae Yeom. 2019. "Interaction of Arsenic Species with Organic Ligands: Competitive Removal from Water by Coagulation-Flocculation-Sedimentation (C/F/S)." Molecules 24, no. 8: 1619.
The widespread use of copper oxide nanoparticles (CuO NPs) and surfactants in various consumer products makes it likely that they coexist in aqueous environments, making it important to study the effects of surfactants on the fate and transport behavior of CuO NPs. The present study aims to investigate the influence of anionic sodium lauryl sulfate (SLS) and nonionic nonylphenol ethoxylate (NPEO, Tergitol NP-9), on CuO NPs adsorption, aggregation, and removal from water by the coagulation process. The result of the sorption study indicates that both surfactants could be adsorbed on the surface of CuO NPs, and that SLS remarkably decreases the ζ potential as well as the hydrodynamic diameter (HDD) of CuO as compared to NP-9. The kinetic aggregation study showed that both SLS and NP-9 reduced the HDD of CuO NPs and retarded the settling rates at surfactant concentrations above 0.015% (w:v) over a 24 h-period. Moreover, enhanced aggregation of CuO NPs was observed in two environmental waters as compared to pure water, which could be related to their high ionic strength. The addition of surfactants in natural waters has been shown to reduce the aggregation and sedimentation of CuO; however, the reductive effect of SLS was more pronounced than that of NP-9. Finally, the coagulation results showed that the removal efficiencies of CuO, Cu2+, and the surfactant in all tested waters at optimum ferric chloride dosage reached around 98, 95, and 85%, respectively. Furthermore, the coagulation mechanism revealed that the combination of charge neutralization and adsorptive micellar flocculation (AMF) might be involved in the removal of both pollutants. The results of the present study provide new insight into the environmental behavior of coexisting NPs and surfactants in wastewater treatment processes.
Rizwan Khan; Muhammad Ali Inam; Sarfaraz Khan; Andrea Navarro Jiménez; Du Ri Park; Ick Tae Yeom. The Influence of Ionic and Nonionic Surfactants on the Colloidal Stability and Removal of CuO Nanoparticles from Water by Chemical Coagulation. International Journal of Environmental Research and Public Health 2019, 16, 1260 .
AMA StyleRizwan Khan, Muhammad Ali Inam, Sarfaraz Khan, Andrea Navarro Jiménez, Du Ri Park, Ick Tae Yeom. The Influence of Ionic and Nonionic Surfactants on the Colloidal Stability and Removal of CuO Nanoparticles from Water by Chemical Coagulation. International Journal of Environmental Research and Public Health. 2019; 16 (7):1260.
Chicago/Turabian StyleRizwan Khan; Muhammad Ali Inam; Sarfaraz Khan; Andrea Navarro Jiménez; Du Ri Park; Ick Tae Yeom. 2019. "The Influence of Ionic and Nonionic Surfactants on the Colloidal Stability and Removal of CuO Nanoparticles from Water by Chemical Coagulation." International Journal of Environmental Research and Public Health 16, no. 7: 1260.
The presence of natural organic matter (NOM) in drinking water sources can stabilize toxic antimony (Sb) species, thus enhancing their mobility and causing adverse effects on human health. Therefore, the present study aims to quantitatively explore the complexation of hydrophobic/hydrophilic NOM, i.e., humic acid (HA), salicylic acid (SA), and L-cysteine (L-cys), with Sb in water. In addition, the removal of Sb(III, V) species and total organic carbon (TOC) was evaluated with ferric chloride (FC) as a coagulant. The results showed a stronger binding affinity of hydrophobic HA as compared to hydrophilic NOM. The optimum FC dose required for Sb(V) removal was found to be higher than that for Sb(III), due to the higher complexation ability of hydrophobic NOM with antimonate than antimonite. TOC removal was found to be higher in hydrophobic ligands than hydrophilic ligands. The high concentration of hydrophobic molecules significantly suppresses the Sb adsorption onto Fe precipitates. An isotherm study suggested a stronger adsorption capacity for the hydrophobic ligand than the hydrophilic ligand. The binding of Sb to NOM in the presence of active Fe sites was significantly reduced, likely due to the adsorption of contaminants onto precipitated Fe. The results of flocs characteristics revealed that mechanisms such as oxidation, complexation, charge neutralization, and adsorption may be involved in the removal of Sb species from water. This study may provide new insights into the complexation behavior of Sb in NOM-laden water as well as the optimization of the coagulant dose during the water treatment process.
Muhammad Ali Inam; Rizwan Khan; Du Ri Park; Sarfaraz Khan; Ahmed Uddin; Ick Tae Yeom. Complexation of Antimony with Natural Organic Matter: Performance Evaluation during Coagulation-Flocculation Process. International Journal of Environmental Research and Public Health 2019, 16, 1092 .
AMA StyleMuhammad Ali Inam, Rizwan Khan, Du Ri Park, Sarfaraz Khan, Ahmed Uddin, Ick Tae Yeom. Complexation of Antimony with Natural Organic Matter: Performance Evaluation during Coagulation-Flocculation Process. International Journal of Environmental Research and Public Health. 2019; 16 (7):1092.
Chicago/Turabian StyleMuhammad Ali Inam; Rizwan Khan; Du Ri Park; Sarfaraz Khan; Ahmed Uddin; Ick Tae Yeom. 2019. "Complexation of Antimony with Natural Organic Matter: Performance Evaluation during Coagulation-Flocculation Process." International Journal of Environmental Research and Public Health 16, no. 7: 1092.
The use of zinc oxide nanoparticles (ZnO NPs) and polybrominated diphenyl ethers (PBDPEs) in different products and applications leads to the likelihood of their co-occurrence in the aquatic system, making it important to study the effect of PBDPEs on the fate and transport of ZnO NPs. In this study, we determine the influence of PBDPEs (BDPE-47 and BDPE-209) on the colloidal stability and physicochemical properties of ZnO NPs in different aqueous matrices. The results indicated the shift in ζ potential of ZnO NP from positive to negative in the presence of both PBDPEs in all tested waters; however, the effect on the NPs surface potential was specific to each water considered. The lower concentration of the PBDPEs (e.g., 0.5 mg/L) significantly reduced the ζ potential and hydrodynamic diameter (HDD) of ZnO NP, even in the presence of high content of dissolved organic matter (DOM) in both freshwater and industrial wastewater. Moreover, both BDPE-47 and BDPE-209 impede the agglomeration of ZnO NP in simple and natural media, even in the presence of monovalent and polyvalent cations. However, the effect of BDPE-47 on the ζ potential, HDD, and agglomeration of ZnO NP was more pronounced than that of BDPE-209 in all tested waters. The results of Fourier transform infrared (FT-IR) and X-ray Photon Spectroscopy (XPS) further confirm the adsorption of PBDPEs onto ZnO NP surface via aromatic ether groups and Br elements. The findings of this study will facilitate a better understanding of the interaction behavior between the ZnO NPs and PBDPEs, which can reduce the exposure risk of aquatic organisms to both pollutants.
Rizwan Khan; Muhammad Ali Inam; Sarfaraz Khan; Du Ri Park; Ick Tae Yeom. Interaction between Persistent Organic Pollutants and ZnO NPs in Synthetic and Natural Waters. Nanomaterials 2019, 9, 472 .
AMA StyleRizwan Khan, Muhammad Ali Inam, Sarfaraz Khan, Du Ri Park, Ick Tae Yeom. Interaction between Persistent Organic Pollutants and ZnO NPs in Synthetic and Natural Waters. Nanomaterials. 2019; 9 (3):472.
Chicago/Turabian StyleRizwan Khan; Muhammad Ali Inam; Sarfaraz Khan; Du Ri Park; Ick Tae Yeom. 2019. "Interaction between Persistent Organic Pollutants and ZnO NPs in Synthetic and Natural Waters." Nanomaterials 9, no. 3: 472.
The increased use of engineered nanoparticles (ENPs), such as copper oxide nanoparticles (CuO NPs), in commercial products and applications raises concern regarding their possible release into freshwater sources. Therefore, their removal from water is important to eliminate adverse environmental and human health effects. In this study, the effects of pH and natural organic matter (NOM), i.e., humic acid (HA) and salicylic acid (SA) on the removal of CuO NPs by coagulation/flocculation/sedimentation (C/F/S) were evaluated. The results indicated that pH significantly affects the coagulation efficiency, where 10–60% CuO NPs removal was achieved under extreme acidic/alkaline conditions. However, at neutral pH, removal of up to 90% was observed with a lower ferric chloride (FC) dosage (0.2 mM). The coagulation efficiency and mechanism were strongly affected by the type of Fe species present in the aqueous phase, which is mainly controlled by pH. Higher concentrations of both HA and SA decrease the CuO NPs agglomeration rate, and thereby improve the colloidal stability due to the NOM molecules adsorbed onto the NPs surface. The presence of hydrophobic HA needs a higher FC dosage of 0.5–0.8 mM than a dosage of hydrophilic SA of 0.25–0.35 mM, to obtain a similar CuO coagulation efficiency. Moreover, higher removals of dissolved organic carbon (DOC) and UV254 were observed more in hydrophobic NOM than in hydrophilic. The results of the Fourier transform infrared (FT-IR) analysis of FC composite flocs confirm that the charge neutralization and enmeshment of coagulant might be a possible removal mechanism. The findings of the current study may provide critical information in the prediction of the fate, mobility, and removal of CuO NPs during C/F/S in water treatment.
Rizwan Khan; Muhammad Ali Inam; Du Ri Park; Sarfaraz Khan; Muhammad Akram; Ick Tae Yeom. The Removal of CuO Nanoparticles from Water by Conventional Treatment C/F/S: The Effect of pH and Natural Organic Matter. Molecules 2019, 24, 914 .
AMA StyleRizwan Khan, Muhammad Ali Inam, Du Ri Park, Sarfaraz Khan, Muhammad Akram, Ick Tae Yeom. The Removal of CuO Nanoparticles from Water by Conventional Treatment C/F/S: The Effect of pH and Natural Organic Matter. Molecules. 2019; 24 (5):914.
Chicago/Turabian StyleRizwan Khan; Muhammad Ali Inam; Du Ri Park; Sarfaraz Khan; Muhammad Akram; Ick Tae Yeom. 2019. "The Removal of CuO Nanoparticles from Water by Conventional Treatment C/F/S: The Effect of pH and Natural Organic Matter." Molecules 24, no. 5: 914.
The zinc oxide nanoparticles (ZnO NPs) and surfactants that are widely used in commercial and industrial products lead to the likelihood of their co-occurrence in natural water, making it essential to investigate the effect of surfactants on the fate and mobility of ZnO NPs. The present study seeks to elucidate the effect of an anionic sodium dodecyl sulfate (SDS) and a nonionic nonylphenol ethoxylate (NPEO), on ZnO NPs adsorption, aggregation, dissolution, and removal by the coagulation process. The results indicate that the presence of SDS in ZnO NPs suspension significantly reduced the ζ-potential and hydrodynamic diameter (HDD), while the effect of NPEO was found not to be significant. The sorption of SDS and NPEO by ZnO NPs were fitted with Langmuir model, but the Freundlich isotherm was more suitable for SDS at pH 9.0. Moreover, the adsorption was strongly pH-dependent due to the formation of mono-bilayer patches onto the NPs. The SDS remarkably affect the dissolution and aggregation phenomena of ZnO NPs in natural waters as compared to NPEO. Finally, the coagulation results showed that the removal efficiency of ZnO, Zn2+ and the surfactant in synthetic and wastewaters at optimum ferric chloride (FC) dosage reached around 85–98% and 20–50%, respectively. Coagulation mechanism investigation demonstrated that the cooperation of charge neutralization and adsorptive micellar flocculation (AMF) might play an important role. In summary, this study may provide new insight into the environmental behavior of coexisting ZnO NPs and surfactants in water treatment processes, and it may facilitate their sustainable use in commercial products and processes.
Rizwan Khan; Muhammad Inam; Muhammad Iqbal; Muhammad Shoaib; Du Park; Kang Lee; SooKyo Shin; Sarfaraz Khan; Ick Yeom. Removal of ZnO Nanoparticles from Natural Waters by Coagulation-Flocculation Process: Influence of Surfactant Type on Aggregation, Dissolution and Colloidal Stability. Sustainability 2018, 11, 17 .
AMA StyleRizwan Khan, Muhammad Inam, Muhammad Iqbal, Muhammad Shoaib, Du Park, Kang Lee, SooKyo Shin, Sarfaraz Khan, Ick Yeom. Removal of ZnO Nanoparticles from Natural Waters by Coagulation-Flocculation Process: Influence of Surfactant Type on Aggregation, Dissolution and Colloidal Stability. Sustainability. 2018; 11 (1):17.
Chicago/Turabian StyleRizwan Khan; Muhammad Inam; Muhammad Iqbal; Muhammad Shoaib; Du Park; Kang Lee; SooKyo Shin; Sarfaraz Khan; Ick Yeom. 2018. "Removal of ZnO Nanoparticles from Natural Waters by Coagulation-Flocculation Process: Influence of Surfactant Type on Aggregation, Dissolution and Colloidal Stability." Sustainability 11, no. 1: 17.
In most countries, arsenic (As) and antimony (Sb) are regulated pollutants, due to their significant impacts on the environment and human health. Iron-based (Fe) coagulants play a fundamental role in the removal of both elements from aqueous media. This study aims to investigate the competitive removal of As and Sb in relation to Fe solubility. Coagulation experiments were conducted in synthetic water under various pH and contaminant loading, using ferric chloride (FC) as a coagulant. In the single system, the pentavalent species significantly reduced the Fe solubility and thereby enhanced the mobility of As and Sb under these environmental conditions. The coexistence of pentavalent and trivalent species in the binary system considerably decreases the Fe solubility at acidic conditions while enhancing the dissolution under alkaline conditions, thus affecting the overall removal of both species. The presence of four redox species in the quaternary system decreases the Fe solubility remarkably over a wide pH range, with better Sb removal, as compared to As under similar conditions. The adsorption study of the single system showed a decrease in As(V) adsorption capacity at higher concentration, while in the binary system, the Sb(III) showed strong adsorption potential, compared to other species. In the quaternary system, the presence of all four redox species has a synergistic effect on total Sb adsorption, in comparison to the total As. Furthermore, the results of Fourier transform infrared (FT-IR) analysis of FC composite contaminant flocs confirm that the combined effect of charge neutralization and inner sphere complexation might be a possible removal mechanism. These findings may facilitate the fate, transport and comparative removal of redox species in the heterogeneous aquatic environment.
Muhammad Ali Inam; Rizwan Khan; Du Ri Park; Babar Aijaz Ali; Ahmed Uddin; Ick Tae Yeom. Influence of pH and Contaminant Redox Form on the Competitive Removal of Arsenic and Antimony from Aqueous Media by Coagulation. Minerals 2018, 8, 574 .
AMA StyleMuhammad Ali Inam, Rizwan Khan, Du Ri Park, Babar Aijaz Ali, Ahmed Uddin, Ick Tae Yeom. Influence of pH and Contaminant Redox Form on the Competitive Removal of Arsenic and Antimony from Aqueous Media by Coagulation. Minerals. 2018; 8 (12):574.
Chicago/Turabian StyleMuhammad Ali Inam; Rizwan Khan; Du Ri Park; Babar Aijaz Ali; Ahmed Uddin; Ick Tae Yeom. 2018. "Influence of pH and Contaminant Redox Form on the Competitive Removal of Arsenic and Antimony from Aqueous Media by Coagulation." Minerals 8, no. 12: 574.
The large-scale production and usage of zinc oxide nanoparticles (ZnO NPs) may lead to their post-release into the aquatic environment. In this study, the effect of hydrophobic/hydrophilic organic ligands on sorption and sedimentation of ZnO NPs has been systematically investigated. In addition, the coagulation efficiency of ZnO NPs, Zn2+, dissolved organic carbon (DOC), and UV254 with varying ferric chloride (FC) dosages in synthetic waters were also evaluated. The results showed that the higher concentration of organic ligands, i.e., humic acid (HA), salicylic acid (SA), and L-cysteine (L-cys) reduced the ζ-potential and hydrodynamic diameter (HDD) of particles, which enhanced the NPs stability. The adsorption of organic ligands onto ZnO NPs was fitted with the Langmuir model, with maximum adsorption capacities of 143, 40.47, and 66.05 mg/g for HA, SA and L-cys respectively. Removal of up to 95% of ZnO NPs and Zn2+ was achieved in studied waters at the effective coagulation zone (ECR), above which excess charge induced by coagulant restabilized the NPs in suspension. Moreover, the removal rate of DOC and UV254 were found to be higher in hydrophobic waters than hydrophilic waters. The width of ECR strongly depends on the characteristics of source water. The waters with hydrophobic ligand and higher UV254 values require more coagulant than hydrophilic waters to achieve the similar ZnO NPs and Zn2+ removal. The results of Fourier transform infrared (FT-IR) analysis of ZnO NPs composite contaminant flocs indicated that the combined effect of enmeshment and charge neutralization might be a possible removal mechanism. These findings may facilitate the prediction of fate, transport, and removal of ZnO NPs in the natural waters, and might contribute to risk assessment, as well as decision making about engineered nanoparticles (ENPs) in aquatic systems.
Rizwan Khan; Muhammad Ali Inam; Du Ri Park; Saba Zam Zam; SooKyo Shin; Sarfaraz Khan; Muhammad Akram; Ick Tae Yeom. Influence of Organic Ligands on the Colloidal Stability and Removal of ZnO Nanoparticles from Synthetic Waters by Coagulation. Processes 2018, 6, 170 .
AMA StyleRizwan Khan, Muhammad Ali Inam, Du Ri Park, Saba Zam Zam, SooKyo Shin, Sarfaraz Khan, Muhammad Akram, Ick Tae Yeom. Influence of Organic Ligands on the Colloidal Stability and Removal of ZnO Nanoparticles from Synthetic Waters by Coagulation. Processes. 2018; 6 (9):170.
Chicago/Turabian StyleRizwan Khan; Muhammad Ali Inam; Du Ri Park; Saba Zam Zam; SooKyo Shin; Sarfaraz Khan; Muhammad Akram; Ick Tae Yeom. 2018. "Influence of Organic Ligands on the Colloidal Stability and Removal of ZnO Nanoparticles from Synthetic Waters by Coagulation." Processes 6, no. 9: 170.
The dynamic nature of engineered nanoparticle (ENP) aggregation behavior and kinetics are of paramount importance in the field of toxicological and environmental nanotechnology. The Taguchi orthogonal array (OA) L27(313) matrix based on a fractional factorials design was applied to systematically evaluate the contribution and significance of water chemistry parameters (pH, temperature, electrolyte, natural organic matter (NOM), content and type) and their interactions in the aggregation behavior of zinc oxide nanoparticles (ZnO NPs). The NPs were dispersed into the solution using a probe-sonicator cell crusher (Bio-safer, 1200-90, Nanjing, China). The data were obtained from UV–Vis spectroscopy (Optizen 2120 UV, Mecasys, Daejeon, Korea), Fourier Transform Infrared Spectrometery (FT-IR 4700, spectroscopy, a JASCO Analytical Instruments, Easton, Pennsylvania, USA) and particle electrophoresis (NanoZS, Zetasizer, Malvern Instruments Ltd., Worcestershire, UK). The dataset revealed that Taguchi OA matrix is an efficient approach to study the main and interactive effects of environmental parameters on the aggregation of ZnO NPs. In addition, the aggregation profile of ZnO NPs was significantly influenced by divalent cations and NOM. The result of the FT–IR data presents a possible mechanism of ZnO NP stabilization in the presence of different NOM. This data may be helpful to predict the aggregation behavior of ZnO NPs in environmental and ecotoxicological contexts.
Rizwan Khan; Muhammad Ali Inam; Du Ri Park; Saba Zam Zam; Ick Tae Yeom. Taguchi Orthogonal Array Dataset for the Effect of Water Chemistry on Aggregation of ZnO Nanoparticles. Data 2018, 3, 21 .
AMA StyleRizwan Khan, Muhammad Ali Inam, Du Ri Park, Saba Zam Zam, Ick Tae Yeom. Taguchi Orthogonal Array Dataset for the Effect of Water Chemistry on Aggregation of ZnO Nanoparticles. Data. 2018; 3 (2):21.
Chicago/Turabian StyleRizwan Khan; Muhammad Ali Inam; Du Ri Park; Saba Zam Zam; Ick Tae Yeom. 2018. "Taguchi Orthogonal Array Dataset for the Effect of Water Chemistry on Aggregation of ZnO Nanoparticles." Data 3, no. 2: 21.
Zinc oxide nanoparticles (ZnO NPs) are among the most widely used engineered nanoparticles (ENPs) in various commercial sectors to achieve both social and economic benefits. The post-use release of these NPs to the environment is inevitable, and may pose threat to the human and eco-system. In the present study, we investigated the influence of single and multiple environmental factors on sedimentation behavior of ZnO NPs. The fractional-factorial method based on Taguchi orthogonal array (OA) L27(313) design matrix was used for systematic investigation on the contribution and significance of multiple factors and their interactions. The result of single-factor showed that the ZnO NPs were unstable at or near pHzpc, with high electrolyte concentration; however, the adsorption of natural organic matter (NOM) i.e., humic acid, salicylic acid, and citric acid reverses the surface charge and enhanced NP stability. The Fourier transform infrared (FT-IR) analysis confirms the organic capping ligands on the NP surface. Moreover, the matrix result of analysis of variance (ANOVA) showed that electrolyte concentration and type, and NOM concentration were the most significant factors (p < 0.001) in promoting and influencing aggregation, while the interaction between the factors was also found insignificant. In addition, the result of aggregation kinetics and environmental water samples indicated that the mobility of ENPs may vary substantially in an environment with complex and heterogeneous matrices. This study may contribute to better understanding and prediction of the sedimentation behavior and fate of ZnO NPs in aqueous environments, to facilitate their sustainable use in products and process.
Rizwan Khan; Muhammad Ali Inam; Saba Zam Zam; Du Ri Park; Ick Tae Yeom. Assessment of Key Environmental Factors Influencing the Sedimentation and Aggregation Behavior of Zinc Oxide Nanoparticles in Aquatic Environment. Water 2018, 10, 660 .
AMA StyleRizwan Khan, Muhammad Ali Inam, Saba Zam Zam, Du Ri Park, Ick Tae Yeom. Assessment of Key Environmental Factors Influencing the Sedimentation and Aggregation Behavior of Zinc Oxide Nanoparticles in Aquatic Environment. Water. 2018; 10 (5):660.
Chicago/Turabian StyleRizwan Khan; Muhammad Ali Inam; Saba Zam Zam; Du Ri Park; Ick Tae Yeom. 2018. "Assessment of Key Environmental Factors Influencing the Sedimentation and Aggregation Behavior of Zinc Oxide Nanoparticles in Aquatic Environment." Water 10, no. 5: 660.
Coagulation and precipitation appear to be the most efficient and economical methods for the removal of antimony from aqueous solution. In this study, antimony removal from synthetic water and Fe solubility with ferric chloride (FC) coagulation has been investigated. The effects of pH, FC dosage, initial antimony loading and mixed Sb(III), Sb(V) proportions on Fe solubility and antimony removal were studied. The results showed that the Sb(III) removal efficiency increased with the increase of solution pH particularly due to an increase in Fe precipitation. The Sb(V) removal was influenced by the solution pH due to a change in Fe solubility. However, the Fe solubility was only impaired by the Sb(III) species at optimum pH 7. The removal efficiencies of both Sb species were enhanced with an increase in FC dose. The quantitative analysis of the isotherm study revealed the strong adsorption potential of Sb(III) on Fe precipitates as compared to Sb(V). Furthermore, the removal behavior of antimony was inhibited in mixed proportion with high Sb(V) fraction. In conclusion, this study contributes to better understanding the fate of Sb species, their mobilities, and comparative removal behavior, with implications for Fe solubility using ferric chloride in different aqueous environments.
Muhammad Ali Inam; Rizwan Khan; Du Ri Park; Yong-Woo Lee; Ick Tae Yeom. Removal of Sb(III) and Sb(V) by Ferric Chloride Coagulation: Implications of Fe Solubility. Water 2018, 10, 418 .
AMA StyleMuhammad Ali Inam, Rizwan Khan, Du Ri Park, Yong-Woo Lee, Ick Tae Yeom. Removal of Sb(III) and Sb(V) by Ferric Chloride Coagulation: Implications of Fe Solubility. Water. 2018; 10 (4):418.
Chicago/Turabian StyleMuhammad Ali Inam; Rizwan Khan; Du Ri Park; Yong-Woo Lee; Ick Tae Yeom. 2018. "Removal of Sb(III) and Sb(V) by Ferric Chloride Coagulation: Implications of Fe Solubility." Water 10, no. 4: 418.