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Scatter plots showing linear regression lines and correlation coefficients between concentrations and XRF-CS counts (100 s exposure time, with the standard deviation of each measurement) of resin reference standards for elements generally used in pollution studies (Cr, Mn, Ni, Cu, Zn, Pb).
Source publication
Conventional pollution monitoring strategies for heavy metals are often costly and unpractical. Innovative sampling and analytical approaches are therefore needed to efficiently monitor large areas. This study presents a novel, simple, fast, and inexpensive method to monitor heavy metal pollution that uses cation-exchange resin sachets and the micr...
Contexts in source publication
Context 1
... easily installed and left for suitable times depending on the motivation of the monitoring program. The sensitive and non-destructive XRF-CS can therefore fulfill the demand to quantitatively assess heavy metal concentrations of the resin samples in a fast and economical manner, which allows for archiving samples of potential legal significance (Fig. ...
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... results of resin reference standards. Due to different combinations of standard solutions and stirring speeds, the 17 resin reference standards cover the concentration range from few ppm to thousands of ppm for each tested metal (Fig. 1, X-axis). All the tested elements, including the pollution-related Cr, Mn, Ni, Cu, Zn, Pb and the nature-related Ca, Ti, show excellent linear correlations (R 2 ≥ 0.97) between XRF-CS counts and absolute concentrations calculated by Equation 1 (Fig. 1 for Cr, Mn, Ni, Cu, Zn, Pb and Fig. S3 for Ca, Ti). Such a finding also demonstrates that, ...
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... standards cover the concentration range from few ppm to thousands of ppm for each tested metal (Fig. 1, X-axis). All the tested elements, including the pollution-related Cr, Mn, Ni, Cu, Zn, Pb and the nature-related Ca, Ti, show excellent linear correlations (R 2 ≥ 0.97) between XRF-CS counts and absolute concentrations calculated by Equation 1 (Fig. 1 for Cr, Mn, Ni, Cu, Zn, Pb and Fig. S3 for Ca, Ti). Such a finding also demonstrates that, compared to the sediment which is the originally designed matrix for the micro-XRF core scanner, dry and homogenous resins run well and enable easy application of the XRF-CS ...
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... since all the pollution-related elements have high detectability with the XRF-CS technique and are expected to have high concentrations in the wastewater, 100 s exposure time is not necessary and can be further shortened, as suggested by the previous study 29 . Moreover, since standard deviations of all tested elements with different exposure times are rather small (Figs 1, 2, S3 and S4), the homogenous resin samples can be scanned in a lower scanning resolution with automatic spectrum picking software to further lower the measurement time, similar to the procedure proposed by Ohlendorf 30 . Thus, each resin sample can be measured in approximately www.nature.com/scientificreports ...
Citations
... d) Samples are taken from the downstream, middle, and upstream of the Waiheru River, Waitonahitu River, PLN Poka River, and Lantamal River. overcome these constraints, EDAX Orbis Micro X-ray Fluorescence Spectrometry (μ-XRF) was used due to its fast, non-destructive, high-resolution, and multi-element capabilities across various fields of application, including materials science, quality control, environmental science, geology, and archaeology [22,23]. Micro XRF (μ-XRF) equipment offers better spatial resolution than standard XRF equipment [24]. ...
The Inner Ambon Bay (IAB) is an important area for the economic development of the city of Ambon, one of only a few urban areas in eastern Indonesia. This study is intended to monitor the anthropogenic impact on IAB by employing combined rock magnetic and geochemical analyses on 20 samples collected from IAB and the surrounding rivers. Magnetic susceptibility values of samples in the IAB averaged 26.37× 10−8 m3/kg, which is relatively high and comparable to that of contaminated coastal environments. Magnetic susceptibility correlated positively with certain metals such as Cr, Co, Ni, and Mn but negatively with Hg. Geochemical analyses showed that Hg and Ag contents were relatively high but pose only moderate risk to the environment based on the geo-accumulation index. Furthermore, the potential ecological risk index (PERI) showed that there were two points that showed moderate ecological risk. Multivariate statistical analysis (principal component analysis (PCA), Pearson's correlation coefficient (PCC), and hierarchical cluster analysis (HCA)) outlined that the metallic accumulation in the sediments of IAB was related to lithological, geological, and anthropogenic impacts. Therefore, oil spills and household waste are likely major reasons for anthropogenic pollution in the sediments of the IAB.
... 7,8 To remediate the dye from aqueous solutions, many methods are used for dye removal like ion exchange, adsorption process, ultrafiltration, oxidation, reverse osmosis membrane, flocculation, and coagulation. [9][10][11][12][13] Taking into account the cost-effectiveness, the adsorption process is the simplest, safest, and best economical choice for removing heavy metals and dyes from polluted water. 14 There are many types of adsorbents, like carbon nanotube adsorbents, polymer adsorbents, bio-adsorbents, metal oxide adsorbents, and metal-organic framework molecules (MOFs), which have been investigated for removing dyes from wastewater. ...
Herewith, magnetic Zn MOF composite material was utilized as an efficient adsorbent for direct red 81 “DR81” dye from wastewater. The synthesized magnetic MOF was characterized using X-ray diffraction (XRD), field emission transmission electron microscopy (FETEM), Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), thermal gravimetrical analysis (TGA), and Brunauer-Emmett-Teller (BET) surface area analysis. The adsorption profile of DR81 anionic dye onto the prepared magnetic MOF was investigated with various processing parameters such as contact time, dosage, and initial dye concentrations. The optimum dosage from the fabricated magnetic Zn MOF for decontamination of DR81 was 1.0 g l ⁻¹ at pH = 7 after 30 min. The maximum Langmuir monolayer adsorption capacity of the DR81 decontamination via the synthesized magnetic MOF was recorded 67.35 mg g ⁻¹ . These promising data confirmed the availability of the synthesized magnetic MOF composite as an excellent adsorbent material for the adsorption of DR81 from aqueous media.
... In order to remove heavy metals and dyes from aqueous solutions, there are various methods such as adsorption, ion exchange, reverse osmosis, coagulation and flocculation, advanced oxidation, and ultra-filtration [9][10][11][12][13] . Considering cost-effectiveness, the adsorption method is the simple, safe, ideal, and economical option for removing dyes and metal ions from contaminated water 14 . ...
The presence of dyes and heavy metals in water sources as pollutants is harmful to human and animal health. Therefore, this study aimed to evaluate the efficacy of zinc ferrite (ZnFe 2 O 4 ) nanoparticles (ZF-NPs) due to their outstanding properties including cost-effectiveness, availability, and applicability for removal of auramine O (AO), methylene blue (MB), and Cd (II). The effect of the main operating parameters such as AO concentration, MB concentration, Cd (II) concentration, adsorbent amount, solution pH, and sonication time was optimized by the response surface methodology (RSM). Optimal conditions were obtained at adsorbent amount of 0.25 g, pH = 6, sonication time of 15 min, and concentration of 15 mg L ⁻¹ , and more than 91.56% were removed from all three analytes. The adsorption of AO, MB, and Cd (II) onto ZF-NPs followed pseudo-second-order kinetics and the equilibrium data fitted well with Langmuir isotherm. The maximum adsorption capacities of ZF-NPs for AO, MB and Cd (II) were as high as 201.29 mg g ⁻¹ , 256.76 mg g ⁻¹ and 152.48 mg g ⁻¹ , respectively. Also, the reuse of the adsorbent was investigated, and it was found that the adsorbent can be used for up to five cycles. Based on the results of interference studies, it was found that different ions do not have a significant effect on the removal of AO, MB, and Cd (II) in optimal conditions. The ZF-NPs was investigated successfully to remove AO, MB, and Cd (II) from environmental water samples. The results of this study showed that ZF-NPs can be used as a suitable adsorbent to remove AO, MB, and Cd (II) from aqueous solution.
... In many cases, however, the ability to process large quantities of powdered or granular samples in a short time with a minimum of sample preparation outweighs the disadvantage of only obtaining semi-quantitative data. A recent example is the application of ion exchange resins to assess environmental pollution in rivers and drainage systems 11 . Because the resin takes up ions from the water in proportion to the concentration in the water, the concentration of the elements in the resin can be used as a direct measure of the pollution in the water. ...
... Because the resin takes up ions from the water in proportion to the concentration in the water, the concentration of the elements in the resin can be used as a direct measure of the pollution in the water. Huang et al. 11 applied this to a partly industrialized former farmland area in central Taiwan to pinpoint hotspots of heavy metal pollution related to the factories in the area. In short, the resin was placed in sachets that were deployed across the drainage system for a number of days. ...
... For this study, the cation-exchange resin Amberlite TM IR-120 (Rohm and Hass, USA) cf. 14-16 was chosen because it has already been deployed in at least two studies using resin sachets and XRF analysis 11,12 . About 4 g of the resin was filled into polyethylene (PE) net sachets that were then placed in standardized solutions prepared from Merck Certipur® ICP standards (Product numbers 1.11355.0100 ...
Detecting clandestine, intermittent release of heavy metal pollution into natural and man-made water ways is challenging. Conventional chemical methods are both labor intensive and expensive. A recent approach combining ion-exchange resins with the capabilities of X-ray fluorescence core scanners (XRF-CS) therefore is of great interest. In short, ion-exchange resin is deployed in the water using small sachets, the resin is then collected, dried, filled into sample holders and scanned using XRF-CS. Ion-exchange resins take up heavy metals in proportion to the concentration in the ambient water, with a correlation coefficient (R²) between concentration and XRF-CS counts better than 0.96 for most elements. However, a number of parameters influence the measurements. Different drying methods introduce differences in the XRF counts because of lattice bound water, resin shrinkage, and disaggregation of the resin particles. Furthermore, the newly developed sample carrier, which was constructed using 3D printed polymers, contains trace amounts of elements that may influence the sample measurements through edge effects and secondary fluorescence. In the tested sample carrier materials, substantial levels of Cr, Fe, Co, and Zn were detected, while Ca, Ti, Ni, Cu, Ga showed variable levels. Ba, Tl and Bi show very low levels, and Pb is only of importance in the PLA carrier. It is therefore necessary to streamline the analysis-process to ensure that the variations in sample treatment and drying and filling methods are minimized. It is also recommended that only spectra from the center of the compartments are used for the evaluation to avoid edge effects caused by secondary fluorescence of metals in the compartment walls. Although the technique of using ion-exchange resin sachets and XRF-CS analysis is only semi-quantitative, it is a cost effective and fast way to monitor large areas for environmental pollution, and the new sample carrier greatly contributes to make the process faster and less error prone.
... The cation-or anion-exchange resins have also been developed to extract heavy metals in wastewater with high removal capability and fast kinetics. However, the lower pH might limit the application of the ion-exchange resins (Huang et al., 2019;Yin et al., 2019). As for the adsorption method, the metal removal potential is specifically associated with the accessible adsorption sites, the binding between sorbent and metals, and the coexistence of multiple ions (Heidari et al., 2020;. ...
Since heavy metals have been regarded as ubiquitous environmental pollutants, the exploitation of bacterial biosorption has been suggested as an applicable method for being employed for heavy metal depletion. The present study aimed to characterize the function of Lactobacillus paracasei in the presence of Pb (II) and Cd (II). The simultaneous effect of pH, initial metal concentration, and inoculum size demonstrated the Pb (II) removal of 85.77% at the lowest pH, while the inoculum size was enhanced to 45 CFU/100 ml. The maximum Cd (II) removal was obtained at a high level of pH and inoculum size, while the metal concentration was reduced to 30 ppb. The addition of Cd (II) concentration in access led to the 10% drop in Cd (II) removal efficiency attributed to the metal toxicity and pH. Additionally, the slight variation in the amount of inoculum size caused the decreasing trend in the Cd (II) removal. According to the obtained results, the benefit of L. paracasei in the biosorption of heavy metals was well‐recognized, which could be suggested as an alternative candidate.
Practitioner points
• Strain of Lactobacillus paracasei as potential probiotics was tested for biosorption.
• A successful response surface method was proposed.
• L. paracasei showed a good efficiency for the lead and cadmium biosorption.
• Biosorption process was effective in removing low metal level from drinking water.
• The maximum biosorption was found to be 85.77% for Pb (II) obtained from the experiment.
... The concentration of the adsorbed heavy metals on the time-lapse capsules could also be rapidly determined by the nondestructive X-ray uorescence core-scanning (XRF-CS) technique. 3,11 According to the results reported by Huang et al., 3 the concentrations of heavy metals determined by the XRF-CS (the increase on the resin) and the conventional analytical method (the reduction in water) exhibited excellent correlations (R 2 > 0.97) even at a short scanning time (<1 s). By doing so, one could identify the potential hot spots of illegal discharge in situ and then keep deploying more time-lapse capsules upstream until the discharge point of the industry is located. ...
... The concentration of the adsorbed heavy metals on the time-lapse capsules could also be rapidly determined by the nondestructive X-ray uorescence core-scanning (XRF-CS) technique. 3,11 According to the results reported by Huang et al., 3 the concentrations of heavy metals determined by the XRF-CS (the increase on the resin) and the conventional analytical method (the reduction in water) exhibited excellent correlations (R 2 > 0.97) even at a short scanning time (<1 s). By doing so, one could identify the potential hot spots of illegal discharge in situ and then keep deploying more time-lapse capsules upstream until the discharge point of the industry is located. ...
Adsorption by ion-exchange resins has been widely used as a cost-effective method for removing numerous hazardous materials, particularly heavy metals, from aqueous solutions. For effectively detecting the illegal discharge of industrial wastewater containing heavy metals, we developed “time-lapse capsules” to trap metallic ions from water bodies. Despite recent progress in the development of time-lapse capsules, a fundamental understanding was still needed to unravel the adsorption behavior of different heavy metals for further improvement of the design and scale-up of the capsule. In this study, three different approaches, viz., response surfaces (from the statistical point of view), time-dependent diffusion-controlled models (from the kinetic point of view), and adsorption isotherms (from the equilibrium point of view), were utilized to evaluate the effect of operating factors on the adsorption of heavy metals from watershed using time-lapse capsules. The obtained results indicated that the key parameters, such as adsorption rate constant, diffusivity, and maximum adsorption capacity, could provide insights into the basis of design criteria.
... At the same time, some heavy metals represent valuable resources and should be recovered, considering their economic value and scarcity [2,3]. Treatment technologies including ion exchange [4], adsorption [5], coagulation [6], membrane separation [7], and electrochemical treatment [8] have been employed for the removal of heavy metals and their recovery for decades. Among these strategies, surfactant micelle or soluble polyelectrolyte assisted/enhanced membrane separation processes provide a high metal removal [9][10][11][12][13], but the efficiency is challenged by membrane cost, chemical dosage and reuse, and energy consumption. ...
The application of polymer-surfactant aggregates (PSAs) to recover heavy metal ions from water is a novel treatment process for aqueous metallic effluents. To better employ this strategy, branched polyethylenimine (PEI), sodium dodecyl sulfate (SDS) and copper ions were selected to investigate their interaction in water and to improve the recyclable PSAs process for metal removal and recovery. Electrostatic association between PEI and SDS caused the formation of PSAs, and the addition of SDS to a partially protonated PEI solution caused a pH increase; however, re-dispersal of PSAs could be achieved via an increase in pH. Precipitation of PSAs depended on pH, SDS/PEI concentration ratio and the total concentration of PEI; the optimal SDS/PEI ratio decreased as pH increased, and a higher concentration of PEI showed a greater potential to precipitate. PEI formed a strong complex with Cu 2+ , with the most stable complex at a PEI/Cu chelation ratio of 4. Acidification decreased the chelation capacity of PEI to Cu 2+ , because of the competition from protons for amino groups. Complexation with Cu 2+ in turn reduced the proton buffer capacity of PEI in a non-acid solution. The removal of Cu 2+ increased by increasing the total PEI concentration, or by increasing pH from 1 to above 4. Ionic strength and hardness had no marked effect on Cu 2+ removal using the PSAs process. Following the initial interaction among PEI, SDS and Cu 2+ , the Cu 2+ could then be released from the PSAs by acidification and the reuse of the PSAs material could be achieved by alkalization. Copper removal and recovery were still up to 98 % and 88 % after three reuse cycles of the PSAs process, respectively.
... In order to overcome this critical issue, several innovative inspection technologies, such as timelapse capsules [7,8], have been developed and deployed in the field tests for identifying the patterns of the heavy metals from the illegal discharge. Apart from the innovative inspection, the integration of continuous automatic sampling techniques and cloud technologies was imperative to provide the real-time monitoring for identifying the sources of pollution and improving the irrigation water quality management. ...
In order to provide the real-time monitoring for identifying the sources of pollution and improving the irrigation water quality management, the integration of continuous automatic sampling techniques and cloud technologies is essential. In this study, we have established an automatic real-time monitoring system for improving the irrigation water quality management, especially for heavy metals such as Cd, Pb, Cu, Ni, Zn, and Cr. As a part of this work, we have first provided several examples on the basic water quality parameters (e.g., pH and electrical conductance) to demonstrate the capacity of data correction by the smart monitoring system, and then evaluated the trend and variance of water quality parameters for different types of monitoring stations. By doing so, the threshold (to initiate early warming) of different water quality parameters could be dynamically determined by the system, and the authorities could be immediately notified for follow-up actions. We have also provided and discussed the representative results from the real-time automatic monitoring system of heavy metals from different monitoring stations. Finally, we have illustrated the implications of the developed smart monitoring system for ensuring the safety of irrigation water in the near future, including integration with automatic sampling for establishing information exchange platform, estimating fluxes of heavy metals to paddy fields, and combining with green technologies for nonpoint source pollution control.
... In this study, HCA was used to evaluate the differences and similarities of the heavy metals in different soil layers, and the grouping results were presented in a dendrogram [46]. Linear regression was used to study the relationship of the heavy metals in the different soil layers [47,48]. ...
In the Syr Darya River watershed, 225 samples from three different layers in 75 soil profiles were collected from irrigated areas in three different spatial regions (I: n = 29; II: n = 17; III: n = 29), and the spatial and vertical variation characteristics of potentially toxic elements (Cd, Co, Cu, Ni, and Zn) and a metallic element (Mn) were studied. The human health risks and enrichment factors were also evaluated in the Syr Darya River watershed of the Aral Sea Basin in Kazakhstan. There were significant differences in the contents of heavy metals in the different soil layers in the different sampling regions. Based on element variation similarity revealed by hierarchical cluster analysis, the elemental groupings were consistent in the different layers only in region I. For regions II and III, the clustered elemental groups were the same between surface layer A and B, but differed from those in the deep layer C. In sampling region I, the heavy metals in surface soils were significantly correlated with the ones in deep layers, reflecting that they were mainly affected by the elemental composition of parent materials. In region II, the significant correlations only existed for Cu, Mn, and Zn between the surface and deep layers. The similar phenomenon with significant correlation was also observed for heavy metals in sampling region III, except for Cd. Finally, enrichment factor was used to study the mobilization and enrichment of potentially toxic elements. The enrichment factors of Zn, Cu, and Cd in surface layer A that were greater than 1.5 accounted for 1.16%, 6.79%, and 24.36% of sampling region I, respectively. In sampling region II, the enrichment factors of Zn, Cu, Cd, and Co that were greater than 1.5 accounted for 0.03%, 4.76%, 0.54%, and 9.03% of the total area, respectively. In sampling region III, only the enrichment factors of Zn, Cu, and Cd that exceeded 1.5 accounted for 0.24%, 4.90%, and 6.89% of the total area, respectively. Although the contents of the heavy metals were not harmful to human health, the effects of human activities on the heavy metals in the irrigated soils revealed by enrichment factors have been shown in this study area.
... The Itrax XRF-CS, which is a unique multi-function scanner for core examination, is commonly used for geological research, and it can detect the element profiles of sediment core. Raychaudhuri et al. [50] used the Itrax XRF-CS to analyze the exposure time of resins in laboratory and field survey. Their results showed that resin samples can be measured in approximately 20 s and identified pollution hot spots in a rapid way. ...
Many factories were built and scattered around the farmlands in Taiwan due to inappropriate land use planning. Illegal effluent discharge of high concentration of metals from the nearby factories has been threatening the farmlands, causing damages to agricultural production, food safety, and human health. Sampling was mostly responsible for monitoring the water quality of the agricultural environment; however, the analysis is of high cost and time consuming. Due to uneasy controlled environmental factors (i.e., illegal effluents) and time-consuming and expensive traditional analysis techniques (i.e., atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS), inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma optical emission spectrometry (ICP-OES), and inductively coupled plasma mass spectrometry (ICP-MS)), we develop a fast-screening method, which is the combination of ion exchange resins and the portable X-ray fluorescence (XRF) spectroscopy to identify the source of contaminants in a mixed industrial and agricultural area in Taoyuan County, Taiwan. The time-lapse ion exchange resin sachet (TIERS) is a non-woven bag that is filled with resins and placed in the irrigation channels for continuously absorbing the metal and trace elements in water. The standardization ratios of Cu/Sr and Zn/Sr were calculated as the pollutant indicators for fast-screening the highly polluted sites of exceedance probability of 2.27% in the monitoring area. The TIERS is verified to detect the metal and trace element concentration in an efficient and sufficient way.
