scholarly journals Kinetics and Size Effects on Adsorption of Cu(II), Cr(III), and Pb(II) Onto Polyethylene, Polypropylene, and Polyethylene Terephthalate Microplastic Particles

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiaoxin Han ◽  
Shiyu Wang ◽  
Xue Yu ◽  
Rolf D. Vogt ◽  
Jianfeng Feng ◽  
...  

Due to its small size, large specific surface area and hydrophobicity, microplastics, and the adsorbed contaminants may together cause potential negative effects on ecosystems and human beings. In this study, kinetics and size effects on adsorption of Cu(II), Cr(III), and Pb(II) onto PE, PP and PET microplastic particles were explored. Results indicated that the PE and PET microplastics have the higher adsorption capacity for Cu(II), Cr(III), and Pb(II) than that for PP microplastic. The adsorption capacity was affected by microplastic types and metal species. Among the three metals, Pb(II) had the largest adsorption amount on microplastic particles, especially on PET particles. Moreover, the adsorption capacities of microplastics increase with the decrease of particle size. The metal adsorption capacity of <0.9 mm microplastics is greater than that of 0.9–2 mm and 2–5 mm microplastics. The size effect on metal adsorption was largest for PE microplastic. More attention should be paid in case of the coexistence of heavy metals and tiny PE and PET microplastics in the environment.

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 486
Author(s):  
Alcina Johnson Sudagar ◽  
Slávka Andrejkovičová ◽  
Fernando Rocha ◽  
Carla Patinha ◽  
Maria R. Soares ◽  
...  

Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) regions of Portugal were used as the aluminosilicate source to compare their effect on the compressive strength and heavy metal adsorption of geopolymers. Natural zeolite, an inexpensive, efficient adsorbent, was used as an additive in formulations to enhance geopolymers’ adsorption capacities and reduce MK utilization’s environmental footprint. Geopolymers were synthesized with the replacement of MK by zeolite up to 75 wt.% (A25, B25—25% MK 75% zeolite; A50, B50—50% MK 50% zeolite; A75, B75—75% MK 25% zeolite; A100, B100—100% MK). The molar ratios of SiO2/Al2O3 and Na2O/Al2O3 were kept at 1 to reduce the sodium silicate and sodium hydroxide environmental impact. Geopolymers’ crystallography was identified using X-ray diffraction analysis. The surface morphology was observed by scanning electron microscopy to understand the effect of zeolite incorporation. Chemical analysis using X-ray fluorescence spectroscopy and energy dispersive X-ray spectroscopy yielded information about the geopolymers’ Si/Al ratio. Compressive strength values of geopolymers obtained after 1, 14, and 28 days of curing indicate high strengths of geopolymers with 100% MK (A100—15.4 MPa; B100—32.46 MPa). Therefore, zeolite did not aid in the improvement of the compressive strength of both MK-based geopolymers. The heavy metal (Cd2+, Cr3+, Cu2+, Pb2+, and Zn2+) adsorption tests exhibit relatively higher adsorption capacities of Barqueiros MK-based geopolymers for all the heavy metals except Cd2+. Moreover, zeolite positively influenced divalent cations’ adsorption on the geopolymers produced from Barqueiros MK as B75 exhibits the highest adsorption capacities, but such an influence is not observed for Alvarães MK-based geopolymers. The general trend of adsorption of the heavy metals of both MK-based geopolymers is Pb2+ > Cd2+ > Cu2+ > Zn2+ > Cr3+ when fitted by the Langmuir isotherm adsorption model. The MK and zeolite characteristics influence geopolymers’ structure, strength, and adsorption capacities.


2010 ◽  
Vol 156-157 ◽  
pp. 900-907 ◽  
Author(s):  
Hong Yu Wang ◽  
Hui Fei Huang

The individual and competitive adsorption capacities of Pb2+, Cu2+ and Zn2+ on clinoptilolite and polymeric Al/Fe modified clinoptilolite were studied. In single systems, adsorption capacity of Pb2+ exceeded that of Cu2+ and Zn2+, and the adsorption capacities of Pb2+, Cu2+ and Zn2+ by polymeric Al/Fe modified clinoptilolite were greater than clinoptilolite. In binary isometric competition adsorption, adsorption capacities of Pb2+, Cu2+ and Zn2+ by clinoptilolite and polymeric Al/Fe modified clinoptilolite decreased compared with single systems. In binary non -isometric competition adsorption, adsorption of Zn2+ from solutions containing a fixed Zn2+ concentration was severely depressed (34%, 26% by clinoptilolite and polymeric Al/Fe (PAFC) modified clinoptilolite, respectively) by increasing the concentration of Cu2+ in the solution, but inverting the roles of Cu2+ and Zn2+ caused only a relatively minor reduction in adsorption of Cu2+. What,s more in other non-equal competition binary systems, the effect of metal adsorption was little. In general, the strength of adsorption followed the order of Pb2+ > Cu2+ > Zn2+ and the order of PAFC modified clinoptilolite > clinoptilolite.


2020 ◽  
Vol 175 ◽  
pp. 09009
Author(s):  
Tatiana Bauer ◽  
Tatiana Minkina ◽  
Saglara Mandzhieva ◽  
Marina Burachevskaya ◽  
Maria Zharkova

Sorption of heavy metals on solid matrices such as soils is one of the key processes which determine the fate of contaminants in the environment. Knowledge of adsorption behavior of heavy metals using biochar is essential for their application in soil remediation. Using the adsorption method, the possibility of using a wood biochar to detoxify Fluvisols contaminated with heavy metals (for example, copper) was studied. It is shown that the addition of biochar increases the metal adsorption capacity of soil. The results were analysed using the Langmuir and Freindlich isotherm equations. It was concluded that biocar can be applied to immobilize heavy metals in contaminated soils.


2013 ◽  
Vol 69 (2) ◽  
pp. 407-413 ◽  
Author(s):  
Shan Qiu ◽  
Fang Ma ◽  
Xu Huang ◽  
Shanwen Xu

In this paper, heavy metal adsorption by ceramsite with or without Bacillus subtilis (B. subtilis) immobilization was studied, and the synergetic effect of ceramsite and bacteria was discussed in detail. To investigate the roles of the micro-pore structure of ceramsite and bacteria in removing heavy metals, the amount of bacteria immobilized on the ceramsite was determined and the effect of pH was evaluated. It was found that the immobilization of B. subtilis on the ceramsite was attributed to the electrostatic attraction and covalent bond. The scanning electron microscopy results revealed that, with the presence of ceramsite, there was the conglutination of B. subtilis cells due to the cell outer membrane dissolving. In addition, the B. subtilis immobilized ceramsite showed a different adsorption capacity for different heavy metals, with the adsorption capacity ranking of La3+ > Cu2+ > Mg2+ > Na+.


2017 ◽  
Vol 76 (7) ◽  
pp. 1867-1874 ◽  
Author(s):  
Xu Zhang ◽  
Huanhuan Yang ◽  
Zhaojie Cui

The negative effects of heavy metals have aroused much attention due to their high toxicity to human beings. Migration and transformation trend of heavy metals have a close relationship with soil safety. Researching on migration and transformation of heavy metals in tailings can provide a reliable basis for pollution management and ecosystem restoration. Heavy metal speciation plays an important role in risk assessment. We chose Anshan tailings for our study, including field investigations and laboratory research. Four typical heavy metal elements of mine tailings {Fe (373.89 g/kg), Mn (2,303.80 mg/kg), Pb (40.99 mg/kg) and Cr (199.92 mg/kg)} were studied via Tessier test in vertical and horizontal direction. The main speciation of heavy metals in Anshan tailings was the residual. However, heavy metals have a strong ability for migration and transformation in vertical and horizontal directions. Its tendency to change from stable to unstable speciation results in increasing bioavailability and potential bioavailability. Fe, Mn, Pb and Cr showed different ability in the migration and transformation process (Mn > Pb > Fe > Cr) depending on the characteristics of heavy metals and physicochemical properties of the environment.


2021 ◽  
Vol 8 ◽  
Author(s):  
Beta Susanto Barus ◽  
Kai Chen ◽  
Minggang Cai ◽  
Rongmao Li ◽  
Huorong Chen ◽  
...  

Microplastics (MPs) and heavy metals are two major types of pollutants that interact with each other, but they are poorly understood. Polystyrene (PS) is one type of MPs that is often detected in aquatic environments. In this study, we examined the adsorption capacity and release rate of heavy metals with respect to different particle sizes of PS, heavy metals, initial heavy metal concentrations, and salinities. Virgin (new) PS with diameters of 20, 50, 130, and 250 μm was used in this study, and four heavy metals (lead, cadmium, copper, and zinc) were used. The results showed that larger PS particle sizes adsorbed more heavy metals even though it took longer to achieve equilibrium adsorption. An increase in heavy metal concentration caused the adsorption capacity (μg g–1) of PS particles to also increase, but the adsorption rate (%) decreased. Increased salinity of the heavy metal solution resulted in a slower adsorption time and a lower adsorption capacity and release rate from the surface of PS particles. Different heavy metals also had different adsorption capacities. Pb was consistently more highly adsorbed by MPs, followed by Cu, Zn, and Cd. Larger PS sizes released heavy metals faster than smaller PS sizes, and the amounts of heavy metals released were higher. The heavy metal with the highest release rate was Cd, followed by Pb, Cu, and Zn. Finally, our findings highlight the interactions between PS and heavy metals and strongly support that PS particles can act as vectors for heavy metals in aquatic systems.


2011 ◽  
Vol 9 (2) ◽  
pp. 348-351 ◽  
Author(s):  
Edyta Kordialik-Bogacka

AbstractProperties of metal solution, environmental conditions and the type of biomaterials (microorganism genus, species or even strain) influence the mechanism of metal biosorption and consequently metal adsorption capacity, affinity and specificity. Cell surface properties determine the metal-microorganism interactions to a large extent. In this work the relationship between yeast surface properties and yeast’s ability to bind cadmium, lead and copper was studied. Surface charge and hydrophobicity before and after biosorption were determined using dye retention and solvent partition assays, respectively. There were differences in the surface charge and relative hydrophobicity among different yeast strains. A higher metal adsorption capacity for more negatively charged yeast cells was observed. Biosorption of heavy metals resulted in modifications to the surface charge and hydrophobicity of yeast cells. However, there were not statistically significant changes in the yeast surface charge and hydrophobicity after binding of heavy metals depending on the nature of the metal, initial metal concentration and solution pH.


Author(s):  
Samuel Ng’ang’a Ndung’u ◽  
Esther Wanja Nthiga ◽  
Ruth Nduta Wanjau ◽  
James Ndiritu

Heavy metals contaminated water has detrimental health effects to human beings and animals not limited to hypertension, kidney damage, cancer and eventual death. Available water treatment methods have proved to not only function at high operation costs and ineffective but also yielded insignificant results to a local ordinary Kenyan citizens. The present study investigates the use of Jackfruit seeds wastes as a low cost adsorbent in adsorption water treatment technique. Raw and modified Jackfruit seeds adsorbent were applied to study kinetic studies of Cu2+, Cd2+ and Pb2+ ions adsorption from an aqueous solution under batch conditions. The adsorption behavior of the three metal ions onto raw and modified adsorbents was monitored spectrophotometrically and analysed with Pseudo-first-order and Pseudo-second-order kinetic models. Correlation coefficients (R2) confirmed that all experimental data fitted Pseudo-second-order with R2 > 0.984 which implied a chemisorption process. Experimental and calculated adsorption capacities was higher for modified adsorbent with Pb2+ ions registering higher values. The rate constants (k2) was higher in modified adsorbent than in raw adsorbent with Pb2+ ions registering highest value of rate of 4.54×10-1 (mg g-1min-1). Adsorption capacities was in the order of Pb2+ > Cu2+ > Cd2+. The results showed viability of the adsorbents for the removal of the heavy metals from waste solution in an economical and environmental friendly manner.


Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 61
Author(s):  
Yuan Zhong ◽  
Yuhong An ◽  
Kebing Wang ◽  
Wanqi Zhang ◽  
Zichu Hu ◽  
...  

Heavy metal wastewater treatment is a huge problem facing human beings, and the application degree of Salix psammophila resources produced by flat stubble is low. Therefore, it is very important to develop high-value products of Salix psammophila resources and apply them in the removal heavy metal from effluent. In this work, we extracted the cellulose from Salix psammophila, and cellulose nanofibers (CNFs) were prepared through TEMPO oxidation/ultrasound. The aerogel spheres derived from Salix psammophila (ASSP) were prepared with the hanging drop method. The experimental results showed that the Cu(II) adsorption capacity of the ASSP composite (267.64 mg/g) doped with TOCNF was significantly higher than that of pure cellulose aerogel spheres (52.75 mg/g). The presence of carboxyl and hydroxyl groups in ASSP enhanced the adsorption capacity of heavy metals. ASSP is an excellent heavy metal adsorbent, and its maximum adsorption values for Cu(II), Mn(II), and Zn(II) were found to be 272.69, 253.25, and 143.00 mg/g, respectively. The abandoned sand shrub resource of SP was used to adsorb heavy metals from effluent, which provides an important reference value for the development of forestry in this sandy area and will have a great application potential in the fields of the adsorption of heavy metals in soil and antibiotics in water.


Author(s):  
Agustina Onyebuchi Ijeomah ◽  
Rebecca Ngoholve Vesuwe ◽  
Bitrus Pam

Vegetables growing in mining areas have become a serious food safety concern because of the high levels of heavy metals always associated with mining. In this study, water used for irrigation, soil, cabbage, green pepper and green beans grown in tin mine areas of Heipang District, Barkin-Ladi LGA of Plateau State were analyzed for lead, cadmium and zinc, using Atomic Absorption Spectrophotometer (AAS). The concentrations of the heavy metals in water, soil, vegetables were all in the order Pb, >> Cd > Zn. In the vegetables, the order was: Pb → cabbage > green beans > green pepper; Cd → green beans > cabbage > green pepper; Zn → cabbage > green pepper = green beans. The transfer factors for all the metals (heavy metal in plant / heavy metal in soil) ranged from 0.95 to 1.48. There were high levels of Pb and Cd in all the vegetables, which may be attributed to the metals in the water used for irrigation. Whilst the concentration of Zn in all the samples were lower than recommended limits, the levels of Pb and Cd in the water, soil and vegetables were higher than the WHO/FEPA standard recommended limits reported for vegetables. The Cd concentrations of the vegetables also exceeded the tolerance thresholds for animals and human beings and therefore consumption of vegetable from the area would endanger the health of the population.


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