This page has only limited features, please log in for full access.
Dye treatments in industrial wastewaters causes numerous obstacles while stains exist normally constant to radiance as well as corrosion and thus, aerobic digestion. The removal of Congo red dye in low concentration from acidic aqueous solution is the main objective of present work. Synthesis of Acrylamide (AM), Diallyl Dimethyl Ammonium Chloride Propylene (DADMAC) and Acryloyloxyethyltrimethyl ammonium chloride (DAC) (PADD) were carried by UV-initiated polymerization, and polyacrylamide (PAM) as contrast sample. Several analytical techniques existed employed to characterization and demonstrate the productive synthesize of PADD, characteristics and composition of the flocculants was studied through FTIR, 1HNMR while thermal stability of PADD in addition PAM was studied by TGA. In addition, the strong structure of surface morphology was confirmed by scanning electronic microscopy (SEM). Established effective process was used to evaluate the flocculation behaviour with special characteristics. Measuring the parameters, dosage of flocculants, flocculation time, temperature, flocculants initial concentration of Congo red dye, stirring speed and zeta potential in removal of Congo red efficiently in acid aqueous environment. These factors presented that in the condition of strong acidity, low concentration and charge neutralization, the adsorption and bridging effect of PADD on Congo red dye was dominant. Under the idyllic conditions concentration of dye 3.0 mg L−1 and pH 6.0, the maximum removal rates of Congo red dye have been 96.45% and 81.10%, PADD and PAM, respectively. PADD provides a scientific basis platform for the removal of Congo red dye efficiently.
Sarfaraz Khan; Huaili Zheng; Qiang Sun; Yongzhi Liu; Hong Li; Wei Ding; Andrea Navarro. Synthesis and characterization of a novel cationic polyacrylamide-based flocculants to remove Congo red efficiently in acid aqueous environment. Journal of Materials Science: Materials in Electronics 2020, 31, 18832 -18843.
AMA StyleSarfaraz Khan, Huaili Zheng, Qiang Sun, Yongzhi Liu, Hong Li, Wei Ding, Andrea Navarro. Synthesis and characterization of a novel cationic polyacrylamide-based flocculants to remove Congo red efficiently in acid aqueous environment. Journal of Materials Science: Materials in Electronics. 2020; 31 (21):18832-18843.
Chicago/Turabian StyleSarfaraz Khan; Huaili Zheng; Qiang Sun; Yongzhi Liu; Hong Li; Wei Ding; Andrea Navarro. 2020. "Synthesis and characterization of a novel cationic polyacrylamide-based flocculants to remove Congo red efficiently in acid aqueous environment." Journal of Materials Science: Materials in Electronics 31, no. 21: 18832-18843.
In this study, a new type of hydrophobic cationic polyacrylamide P (AM-DMC-DABC) (PADD) was synthesized by ultrasonic (US)-initiated polymerization, which is used for the separation and removal of coal mine wastewater. The acrylamide (AM), methacryloyloxyethyl trimethyl ammonium chloride (DMC) and acryloyloxyethyl dimethylbenzyl ammonium chloride (DABC) were used as monomers to prepare). The factors that affecting the US initiated polymerization of PADD were analyzed. Fourier transform infrared spectroscopy (FT-IR), 1H nuclear magnetic resonance (1H NMR) and scanning electron microscopy (SEM) were used to characterize the chemical structure, thermal decomposition performance and surface morphology of the polymers. FT-IR and 1H NMR results showed that PADD was successfully synthesized. In addition, irregular porous surface morphology of PADD were observed by SEM analysis. Under the optimum conditions (pH = 7.0, flocculant dosage = 16.0 mg/L), the excellent flocculation performance (turbidity removal rate (TR) = 98.8%), floc size d50 = 513.467 μm, fractal dimension (Df) = 1.61, flocculation kinetics (KN0) = 27.24 × 10−3·s−1) was obtained by using high-efficiency flocculant PADD. Zeta potential analysis was used to further explore the possible flocculation mechanism of removal. The zeta potential and flocculation analytical results displayed that the flocculation removal process of coal mine wastewater mainly included hydrophobic effect, adsorption, bridging and charge neutralization, and electric patching when PADD was used. The PADD showed more excellent coal mine wastewater flocculation performance than PAD, commercial cationic polyacrylamide (CPAM) CCPAM and PAM. Thus PADD, with its good flocculation effect on coal mine wastewater under relatively wide pH range, had bright practical application value.
Xin Qi; Junling Liu; Cheng Wang; Li; Yicong Liang; Khan Sarfaraz; Shiyao Li; Xiang Li. Synthesis of the Hydrophobic Cationic Polyacrylamide (PADD) Initiated by Ultrasonic and its Flocculation and Treatment of Coal Mine Wastewater. Processes 2020, 8, 62 .
AMA StyleXin Qi, Junling Liu, Cheng Wang, Li, Yicong Liang, Khan Sarfaraz, Shiyao Li, Xiang Li. Synthesis of the Hydrophobic Cationic Polyacrylamide (PADD) Initiated by Ultrasonic and its Flocculation and Treatment of Coal Mine Wastewater. Processes. 2020; 8 (1):62.
Chicago/Turabian StyleXin Qi; Junling Liu; Cheng Wang; Li; Yicong Liang; Khan Sarfaraz; Shiyao Li; Xiang Li. 2020. "Synthesis of the Hydrophobic Cationic Polyacrylamide (PADD) Initiated by Ultrasonic and its Flocculation and Treatment of Coal Mine Wastewater." Processes 8, no. 1: 62.
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 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.
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.