Although surface complexation models have been widely used to describe the adsorption of heavy metals, few studies have verified the feasibility of modeling the adsorption kinetics, edge, and isotherm data with one pH-independent parameter. A close inspection of the derivation process of Langmuir isotherm revealed that the equilibrium constant derived from the Langmuir kinetic model, KS-kinetic, is theoretically equivalent to the adsorption constant in Langmuir isotherm, KS-Langmuir. The modified Langmuir kinetic model (MLK model) and modified Langmuir isotherm model (MLI model) incorporating pH factor were developed. The MLK model was employed to simulate the adsorption kinetics of Cu(II), Co(II), Cd(II), Zn(II) and Ni(II) on MnO2 at pH3.2 or 3.3 to get the values of KS-kinetic. The adsorption edges of heavy metals could be modeled with the modified metal partitioning model (MMP model), and the values of KS-Langmuir were obtained. The values of KS-kinetic and KS-Langmuir are very close to each other, validating that the constants obtained by these two methods are basically the same. The MMP model with KS-kinetic constants could predict the adsorption edges of heavy metals on MnO2 very well at different adsorbent/adsorbate concentrations. Moreover, the adsorption isotherms of heavy metals on MnO2 at various pH levels could be predicted reasonably well by the MLI model with the KS-kinetic constants.
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http://dx.doi.org/10.1016/j.jes.2014.05.036 | DOI Listing |
Front Pediatr
January 2025
Gansu University of Chinese Medicine, Lanzhou, Gansu Province, China.
Background: Previous research has demonstrated that exposure to individual heavy metals elevates the incidence rate of congenital heart defects (CHDs). However, there is a paucity of data concerning the relationship between combined exposure to multiple heavy metals and the occurrence of CHDs. This study seeks to investigate the association between combined heavy metal exposure in pregnant women and the incidence of CHDs in their offspring in Lanzhou, China.
View Article and Find Full Text PDFJ Food Sci Technol
January 2025
Grain Science and Technology Division, Defence Food Research Laboratory, Mysore, Karnataka 570011 India.
This study aimed to compare thirteen different varieties of hyacinth beans analyzedfor their nutritional and antinutritional constituents. The study classified HA-3, HA-4, and Kadale Avare as Lignosus varieties, while the remaining varieties Arka, Pusa, CO, and NS, were classified as Typicus. The protein content ranged from 19.
View Article and Find Full Text PDFFront Nutr
January 2025
Clinical Center of Reproductive Medicine, Lianyungang Maternal and Child Health Hospital, Lianyungang, China.
Background: Salt usage patterns have been associated with a risk of multiple diseases; however, their relationship with heavy metal exposure has not been extensively studied.
Methods: This study analyzed survey data from 11,574 NHANES participants. Weighted linear regression models were used to examine the relationship between the type of salt used by participants, the frequency of adding salt at the table, and the frequency of adding regular or seasoned salt to cooking or food preparation, and urinary concentrations of 10 heavy metals.
Heliyon
January 2025
Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region, Collaborative Innovation Center for Mountain Ecology & Agro-Bioengineering, College of Life Sciences, Guizhou University, Guiyang, 550025, China.
Vegetation change significantly altered the hydrological processes and soil erosion within riparian ecosystems. It is unclear how change in managed vegetation types affect the geochemical behavior of heavy metals (HMs) and magnetic particles in karst riparian areas. Two soil depths of 0-20 cm and 20-40 cm were taken in alien species (), native species and in a typical urban plateau Lake wetland, Caohai lake, China.
View Article and Find Full Text PDFHeliyon
January 2025
Institute of Global Health and Human Ecology, School of Sciences and Engineering, The American University in Cairo, P.O. Box 74, New Cairo, 11835, Egypt.
Heavy metals like lead, mercury, cadmium, and arsenic are environmental pollutants that accumulate in ecosystems and pose significant health risks to humans and wildlife, primarily through food chain contamination where plants absorb heavy metals, affecting their growth and threatening consumer health. Cognitive and cardiovascular functions are particularly affected by exposure to heavy metals even at low concentrations through the induction of oxidative stress. Various analytical techniques are used in measuring heavy metals in different environmental and biological samples.
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