Papers by Keyword: Heavy Metal

Abstract: Sugarcane represents a significant agricultural commodity extensively cultivated in tropical and subtropical regions globally. Following the industrial processing of sugarcane, a substantial quantity of the byproduct known as sugarcane bagasse (SCB) is generated. Due to the overwhelming production of this biomass, bagasse is often incinerated as a method of solid waste management, leading to environmental problems. To remediate poultry wastewater, agricultural residue was repurposed into a bagasse-based bio-adsorbent enhanced with nano-silica and zeolite clay. FTIR analysis indicated the existence of functional groups such as the O-H stretching, C=C stretching, C-H bending, and C-N stretching. SEM-EDX analysis demonstrated that the synthesized bio-adsorbent exhibits a microporous structure, which is beneficial for filtration applications, and consists of varying concentrations of oxygen, carbon, and silicon. Moreover, the composite achieved up to 100% Cd removal, 100% As removal, 54.76% Pb removal, and 40% Hg removal, while reducing coliform counts by 93.42–99.11%. Dissolved oxygen increased by as much as 60.19%, and total ammoniacal nitrogen decreased by up to 42.05%, demonstrating the material’s strong remediation potential. Furthermore, notable enhancements in the physicochemical properties of the poultry wastewater, including temperature and pH, were also documented. This research study elucidates a significant improvement in the treatment of wastewater through the utilization of agricultural by-products sugarcane bagasse, thereby demonstrating the effectiveness of nano-silica and zeolite integration in developing sustainable and efficient adsorbent materials for wastewater remediation.

Abstract: The current study was carried out by determining structural and energetic parameters to theoretically validate the experimental results of the adsorption efficiency of amine-functionalized porous carbon for the elimination of Cu²⁺ ions and Pb²⁺ and detail the reaction mechanism in the aqueous medium. The Density Functional Theory calculations, molecular dynamics, and Monte Carlo simulations were used to investigate the adsorption enhancement mechanism. The calculations were performed using the Dmol3 module of the Materials Studio program (MatS) using the exchange-correlation function M-11L2. DFT calculations were determined for porous carbon (PC) and porous carbon functionalized by ethylene diamine (PC-ED). Indeed, this study aims to reveal the functionalization influence on improving the adsorption efficiency of Cu²⁺ and Pb²⁺ by porous carbon (PC). Overall, the study attempts to explain the experimental results of the improved interactivity of porous carbon functionalized by ethylene diamine concerning Cu²⁺ and Pb²⁺ ions, compared to the reactivity of these ions with the group carboxyl characterizes the porous carbon (PC). The Molecular dynamics and Monte Carlo simulations were used to clarify the interactions between Cu²⁺ or Pb²⁺ ions and porous carbon modelled in the presence or absence of ethylene diamine (PC–ED) function. Hence, the theoretical study showed that the presence of ethylene diamine (C₂H₄(NH₂)₂)_m forms more ligands towards the ions of metal M²⁺ with the interaction bounds lower than ≤ 2.5 Å. The same result is shown by the small adsorption energy obtained in the range of -1140 to -200 kcal/mol for and -1200 to -600 kcal/mol for Pb²⁺ and Cu²⁺, respectively. Therefore, more adsorption of Cu²⁺ and Pb²⁺ ions. The theoretical results obtained agree with the experimental results.

Abstract: Methods of assessing the intensity of plant growth in soils contaminated with elements of heavy metals as a result of military operations can provide important data regarding the migration, bioavailability of chemical compounds for plants, as a result of the formation of chemical compounds, which are key parameters for assessing the phytoremediation potential. The use of various methods of assessing the impact of heavy metals in the soil on plant growth can be evaluated not only based on the degree of environmental risk, but also predict the magnitude of the impact of a complex of chemical elements taking into account synergistic factors based on a statistical assessment based on the Pearson and Spearman complex. It was established that the mutual influence on the formation of active compounds in the soil significantly affects the intensity of plant growth and, accordingly, the negative correlation of the Pearson coefficient with the concentration of heavy metals in the soil for such as Cd, Cr and Ni. A positive correlation in the range of 0.75-0.89 is typical for soil samples with copper, lead, zinc and titanium. The impact of potentially toxic elements on the biometric parameters of plants was determined using germination tests. Slowdown of plant growth in the range of 5-10% was observed for soils with excess content of elements in the following sequence: zinc, lead, nickel, copper, chromium, cadmium and titanium.Statistical analysis was performed based on the results of biometric parameters of plants from germination tests. The application of the t-test (Shapiro-Wilk, p>0.05) established statistical differences in the homogeneity of the dispersion and the normality of the distribution. Under the condition (p=0.05) of normal distribution, the Mann-Whitney test was used. At p>0.05, the Brown-Forsyth test was used to analyze homogeneity of variances with a normal distribution. The use of the Welch test made it possible to establish the fact whether the distribution is normal for homogeneous and heterogeneous dispersion. Based on the Statistica 13.1 program, it was established that the Welch test data confirm the normal distribution of various types of variance.

Abstract: Lead waste that pollutes the environment can cause a variety of serious diseases. Various efforts have been made to remove lead waste from the environment, one of which is through the development of magnetic nanoparticles-based adsorbents. In this work, the synthesis of ZnFe₂O₄-PEG/RGO nanocomposites was carried out through co-precipitation and sonochemical methods. The structure, morphology, function groups, and adsorption performance of the ZnFe₂O₄-PEG/RGO nanocomposites were characterized using XRD, SEM, FTIR, and AAS. X-ray diffraction pattern showed the formation of a single phase ZnFe₂O₄ with a cubic spinel structure. The RGO peak was not detected because the RGO mass was much smaller inside the ZnFe₂O₄-PEG/RGO nanocomposites. Furthermore, refinement analysis through Rietica software obtained crystallite size of ZnFe₂O₄-PEG/RGO were 9.6 nm. The SEM result showed that the morphology of ZnFe₂O₄-PEG tends to be spherically distributed on RGO. Based on FTIR results, the functional groups of ZnFe₂O₄-PEG/RGO nanocomposites showed the presence of Zn-O and Fe-O bonds at 529 cm^-1 and 428 cm^-1. Meanwhile, C-O bonds at wavenumbers 1222 cm^-1 showed typical absorption of RGO. Despite Fe-O and C-O bonds, the presence of C-O-C bonds at wavenumbers of 1031 cm^-1 indicates the characteristics of PEG that successfully coats ZnFe₂O₄ nanoparticles. Interestingly, the AAS results showed that ZnFe₂O₄-PEG/RGO nanocomposites had an excellent performance as lead adsorbents, evidenced by the percentage of adsorption up to 97,7%.

Abstract: Industries such as electroplating, mining etc. produce wastewater that, as it includes various heavy metals such as lead, cadmium, has a potential threat to our environment. If this wastewater is left untreated, soil and water supplies would be polluted. The release of heavy metals into the natural world, has resulted in a number of heavy metals that can cause serious harm to humans and marine life even at trace levels. Thus, this research address the synthesis of oil palm frond (OPF) based mesoporous silica nanoparticle (MSN) which intended for the removal of heavy metal. The MSN were synthesised from OPF via sol-gel method and later utilised as adsorbent to removed lead (Pb) from the aqueous solution. The FTIR results of OPF-based MSN exhibit similar peak with commercially available silica. The MSN adsorbent was then investigated for Pb removal under different parameter including pH, contact time, dosage, concentration, and temperature and analysed using Atomic Absorption Spectroscopy (AAS). The optimum condition was obtained at pH 7, 45 mins of contact time, 0.4 g/L adsorbent dosage under 10 ppm of Pb concentration at 303 K that aid in enhancing Pb removal by the OPF-based MSN. At this condition, MSN successfully removed up to 89% of Pb in aqueous solution with adsorption capacity of the adsorbent is within the range of 22.3 mg/g. This result demonstrates the potential application of MSN from OPF as an adsorbent in Pb removal from wastewater.

Abstract: Municipal solid waste landfills are major sources of environmental pollution. This study evaluated heavy metal concentrations in soils around Pulau Burung Landfill, Penang, Malaysia, to determine the pollution potential of a landfill. Soil samples were collected at depths of 0–20 cm (top), 20–40 cm (center) and 40–60 cm (bottom) around the landfill and at a control site and characterized for various properties and concentrations of Lead (Pb) and Zinc (Zn). Samples of daily soil cover, collected from the same sites where soil samples were collected, were also analyzed for several of heavy metals analysis. The soils were silty sand, mostly acidic (4.45) with low organic matter content (0.41%) and cation exchange capacity (3.15-3.19 meq/100 g). Other basic physico-chemical and adsorption properties were conducted on soil indicated that soil alone is not effective to be used in the landfill to support the pollutant for a long time. Heavy metals concentrations (as background data) in the soils followed the order Iron (Fe) > Zinc (Zn) > Manganese (Mn) > Lead (Pb) > Arsenic (As) > Chromium (Cr) > Cadmium (Cd) > Copper (Cu) > Nickle (Ni) with samples from around the landfill having higher concentrations especially Iron, (Fe) and Zinc, (Zn). For soil profile contribution, heavy metal enrichment was highest at a depth of 40–60 cm. In short, soil alone cannot retain and minimize the migration of heavy metals in landfill based on the results of this study including removal efficiency test. Monitoring of environments around active landfills needs to be ongoing to mitigate negative impacts on humans and the environment.

Abstract: The Co-MoF was identified as better catalyst for colorimetric sensing for effective detection of Hg²⁺ ions. The mimicking activities and oxidise the TMB in the existence of hydrogen peroxide (H₂O₂) to create a blue-colored sample. The oxidation of TMB was greatly delayed or reduced in the existence of bio-molecule Glutathione since of its stronger cations to repair capability. GSH substrates are oxidised when Hg²⁺ is introduced because of the higher interaction of mercury ions for GSH's thiol groups. Hg²⁺ concentrations ranged from 1 to 50 nM, and it exhibits a LOD of 0.28 nM reached in this study. To our surprise, the proposed sensor technology for detecting mercury contamination from industrial wastewater shows great potential.

Abstract: The paper analyzes the impact of personal protective equipment used by the population as a result of the COVID-19 pandemic on the environment. The scale of the additional amount of waste generated as a result of the use of protective face masks, etc. is noted. The globality of the existing problem and its multiparametric impact on the components of the environment are indicated. The short-term effect of a number of disposable protective face masks on the condition of soil by chemical component has been studied. The dependence of leaching of heavy metals from masks on soil acidity was experimentally analyzed, the dynamics of mobile phosphorus and potassium in soil samples was studied. It is shown that the presence of masks in the soil leads to exceeding the standard for zinc content, while for copper content and manganese content exceeding the standard is not observed in the study period, for lead there are fluctuations in content beyond standard value. The need for long-term research on the impact of face masks on the environment, and in particular soils, was noted.

Abstract: This review article presents the usage of various animal bones such as chicken bone, fish bone, pig bone, camel bone, and cow bone as reliable biosorbent materials to remove heavy metals contained in contaminated water and wastewater. The sources and toxicity effects of heavy metal ions are also discussed properly. Then specific insights related to adsorption process and its influential factors along with the proven potentiality of selected biosorbents especially derived from animal bone are also explained. As the biosorbents are rich in particular organic and inorganic compounds and functional groups in nature, they play an important role in heavy metal removal from contaminated solutions. Overall, after conducting study reports on the literature, a brief conclusion can be drawn that animal bone waste has satisfactory efficacy as effective, efficient, and environmentally friendly sorbent material.

Abstract: Heavy metal such as Cu, Fe, and Zn are the most serious contributers to environmental problems. The removal of heavy metal from the environment is the research interest nowdays. The adsorption of Cu, Fe and Zn from wastewater was investigated with various activated carbons as adsorbents. The activated carbons were produced from oil palm leaves by using multi-activation methods. The H₃PO₄, NaOH, ZnCl₂ and KOH were chosen as chemical activating agents. Batch adsorption experiment was used to test the ability of activated carbon to remove Cu, Fe, and Zn from wastewater. The surface characteristics of activated carbon were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption-desorption isotherms. The Activated carbons were able to purify wastewater with a maximum turbidity level of 2.83 NTU. The AC-H₃PO₄ activated carbon showed the highest absorbability of Cu metal as 91.540%, while the highest absorbabilities of Zn and Fe metals were indicated by AC-KOH activated carbon of 22.853% and 82.244% absorption respectively. Therefore, these results enable the oil palm leaves to become a high potential for activated carbon as removal the heavy metals.