Heavy Metals Research Articles

Dual-channel fluorescent probe for detecting SO2 and Hg2+, and dynamic imaging SO2 under Cd2+ in alfalfa (Medicago sativa)

BackgroundAs an antioxidant, SO2 plays a critical role in maintaining the plant's redox balance. At the same time, Hg2+ as heavy metals, will accumulate in plants through soil, often disrupting physiological processes in plants. However, few studies have been reported to examine changes in Hg2+ and SO2 in plants. Here, we developed a dual-channel fluorescent probe NYD, which can differentiate between the detection of Hg2+ and SO2. ResultsThe probe exhibits high sensitivity (LOD, 44 nM for Hg2+ and 26 nM for SO2). When Hg2+ and HSO3− deprotect and attack the double bond by nucleophilic addition, significant emission of fluorescence at 475 nm and 574 nm with blue and red fluorescence respectively. In addition, NYD has the capability to detect the levels of Hg2+ and SO2 in cells and alfalfa seedlings. Meanwhile, the findings indicated that alfalfa seedlings were exposed to Cd2+, which led to redox imbalance and increased endogenous SO2 production. SignificanceWe anticipate that this research will contribute to a better understanding of the functions of SO2 under oxidative stress induced by Cd2+.

Cotinine exposure enhances the association of blood manganese and non-alcoholic fatty liver disease in American children: a cross-sectional study

This cross-sectional survey aims to determine whether cotinine exposure would enhance the relationship between blood manganese (Mn) and non-alcoholic fatty liver disease (NAFLD) in children using the NHANES database. Restricted cubic spline (RCS) and logistic regression analyses were adopted to determine the potential relationship. Besides, we tested the robustness of the results by performing trend tests and subgroup analyses. The study finally enrolled 866 children aged 18 years and below. Blood Mn was linearly linked to NAFLD and the risk of NAFLD was increased with the blood Mn elevation (P < 0.05). There was a notable relationship between blood Mn and NAFLD in crude model 1, which was still significant upon adjustment of all the identified covariates (all P < 0.05). Under Mn exposure, the cotinine-exposed group had a higher risk of NAFLD than the cotinine-unexposed group. In conclusion, blood Mn level is an independent risk factor for pediatric NAFLD, and cotinine exposure can enhance this relationship to some degree. Therefore, reducing cotinine exposure may alleviate detrimental consequences related to exposure to heavy metals in children.

The Use of Waste Materials Red Mud and Fly Ash as Road Embankment Fill

This study provides a comprehensive evaluation of red mud as a sustainable material for road base construction, particularly in combination with bottom ash. Red mud, a by-product of the Bayer process used in alumina extraction, is known for its high alkalinity and heavy metal content. For this reason, this waste material causes environmental challenges. Red mud sourced from the Eti Aluminum Factory in Seydişehir, Konya (Turkey), was stabilized with bottom ash. Then, these waste materials were tested through a number of experiments, such as in relation to their Atterberg limits, compaction characteristics, unconfined compressive strength (UCS), California bearing ratio (CBR), and microstructure through a scanning electron microscopy (SEM) analysis. The results highlight that the UCS of stabilized red mud samples significantly improved with the addition of bottom ash and longer curing periods. Specifically, the UCS values increased from 0.5 MPa to 2.5 MPa after 28 days of curing. Moreover, RM specimens stabilized with 25% bottom ash achieved a CBR value of 146.64% after 28 days, far exceeding Turkey’s road fill material requirement, which mandates a minimum unsoaked CBR value of 15%. These findings indicate that red mud stabilized with bottom ash not only meets but exceeds the structural requirements for road base materials. This approach provides a sustainable solution for the environmental management of red mud while contributing to infrastructure development. Through the recycling of these industrial by-products, this study presents a viable method to reduce waste and support economic and environmental sustainability in road construction projects.

Occupational exposure assessment of heavy metals in human scalp hair among tannery workers in Bahir Dar, Ethiopia: Indication of pollution

Ethiopia, is one of the African countries, has immense potential for skins and hides for the leather industries, which will play a crucial role in converting nations into manufacturing-driven economies through industrialization. The chemicals applied in the tanning process are a serious concern for employees and the community if proper safety measures are not taken. The pollution status of employees working in Anbessa and Bahir Dar tannery factories was evaluated by collecting hair samples. After the hair samples washed with acetone, and deionized water, the hair samples were digested with 4 mL of HNO3 and 2 mL of HClO4 for 1:30 h at 250 °C. The levels of metals (Cr, Pb, Zn, Cu, Ni, and Cd) were subsequently analyzed using a Flame Atomic Absorption Spectrophotometer (FAAS). The mean concentrations of Cu, Ni, Zn, Pb, and Cr in the Anbessa tannery factory workers were 17.34–22.75, 16.38–35.03, 235.4–369.2, 30.46–67.31, and 97.56–189.18, respectively, in the various working departments of the factory. Similarly, the concentrations of Cu, Ni, Zn, Cd, Pb, and Cr in the hair of Bahir Dar tannery workers were 30.1–105.9, 17.88–62.20, 216.9–762.1, 0.35–5.21, 33.42–91.42, and 118.5–305.7, respectively. Chromium was found to be the most accumulated metal next to Zn with in both tannery workers that highlighted significant occupational health risks. The principal component analysis (PCA) analysis provide an insights into the interactions between occupational factors and metal exposure. In conclusion, the results of hair analysis from the employees of tannery factories indicates alarming levels of metal exposure, especially for zinc and chromium, which might pose health problems in long time exposure. Thus, it's critical to monitor occupational activities that can harm human health and the environment.

Ameliorating arsenic and PVC microplastic stress in barley (Hordeum vulgare L.) using copper oxide nanoparticles: an environmental bioremediation approach

The present study investigates the impact of varying concentrations of PVC microplastics (PVC–MPs) – specifically 0 (no PVC–MPs), 2, and 4 mg L− 1 –alongside different arsenic (As) levels of 0 (no As), 150, and 300 mg kg− 1 in the soil, with the concurrent application of copper oxide–nanoparticles (CuO–NPs) at 0 (no CuO –NPs), 25 and 50 µg mL− 1 to barley (Hordeum vulgare L.) plants. This research primarily aims to assess plant growth and biomass, photosynthetic pigments and gas exchange characteristics, oxidative stress indicators, as well as the response of various antioxidants (both enzymatic and non-enzymatic) and their relevant genes expression, proline metabolism, the AsA–GSH cycle, and cellular fractionation within the plants. The findings showed that increased levels of PVC–MPs and As stress in the soil significantly reduced plant growth and biomass, photosynthetic pigments, and gas exchange characteristics. Additionally, PVC–MPs and As stress increased oxidative stress in the roots and shoots, as evidenced by elevated levels of malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL), which in turn stimulated the production of various enzymatic and non-enzymatic antioxidants, gene expression, and sugar content. Furthermore, a notable increase in proline metabolism, the AsA–GSH cycle, and cellular pigmentation was observed. Conversely, the application of CuO–NPs resulted in a substantial improvement in plant growth and biomass, gas exchange characteristics, and the activity of enzymatic and non-enzymatic antioxidants, along with a reduction in oxidative stress. Additionally, CuO–NPs enhanced cellular fractionation while decreasing proline metabolism and the AsA-GSH cycle in H. vulgare plants. These outcomes provide new insights into sustainable agricultural practices and offer significant potential in addressing the critical challenges of heavy metal contamination in agricultural soils.

Dietary silicate minerals relieving cadmium or lead poisoning in juvenile sea cucumber, Apostichopusjaponicus

Industrial activities increase Apostichopus japonicus exposure to toxic heavy metals. This study evaluates the efficacy of three dietary silicate minerals (montmorillonite, zeolite, and kaolin) in relieving cadmium and lead toxicity in A. japonicus. Over four weeks, juvenile A. japonicus (7 − 9 g) were fed diets incorporating montmorillonite, zeolite, or kaolin, replacing sea mud at a 1:1 ratio. Experimental groups were: SM (control with sea mud), M (montmorillonite), Z (zeolite), and K (kaolin). Each group was exposed to cadmium (50 mg kg−1) or lead (100 mg kg−1) at the minimal toxic dose (MTD). Groups M and K demonstrated excellent growth performance, marked by improvements in weight gain rate (WGR), specific growth rate (SGR), feed conversion ratio (FCR), and survival rate (SR). Their coelomic fluid revealed higher enzymatic activities, such as acid phosphatase (ACP), alkaline phosphatase (AKP), catalase (CAT), and superoxide dismutase (SOD). Additionally, groups M and K showed a reduced accumulation of cadmium and lead in their tissues; group K notably excelled in mitigating intestinal tissue damage. In contrast, Group Z exhibited significantly poorer performance. In other aspects, the trends among the three experimental groups were generally similar: the activity of intestinal digestive enzymes declined, intestinal microbiota diversity decreased, and the stability of community composition increased. In summary, the supplementation of montmorillonite and kaolin effectively reduces cadmium and lead toxicity, diminishes oxidative damage, and promotes intestinal health in A. japonicus. These findings provide valuable insights for enhancing safety in A. japonicus aquaculture.

Pollution Profile of the Panvel Creek, Raigad, Maharashtra, India: Analysis of the Heavy Metal Contamination

The concentration of heavy metal levels (Cd, Cu, Hg, Ni, Pb, and Zn) were assessed in water samples from Panvel creek, District Raigad, Maharashtra, West Coast of India. The heavy metals were analysed by using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Results of the study reveal that, Cu, Ni, Zn, and Hg were detected in water samples of Panvel creek whereas Pb and Cd were not reported. Levels of Cu range from not detectable to 0.037 ppm whereas concentration of Ni varies from not detectable to 0.048. Zn is the only metal which is consistently detected at both the sites during all seasons whereas its values were moderately high (0.108 ppm) during the monsoon at both sites. Highest values were recorded for Hg, especially during the pre-monsoon. Highest levels of Ni and Zn were detected at both sites during monsoon season whereas Cu, Pb, Hg and Cd were not detected during monsoon at all sites. Further, Cu and Zn were detected during post-monsoon, while other metals such as Ni, Pb, Hg and Cd remain not detectable. Zn was only heavy metal detected at both sites during all sampling seasons while Pb and Cd were absent from the water samples during all the seasons at all sites. Average concentration of heavy metals reported in Panvel creek was found to be in the order of Hg&gt;Zn&gt;Ni&gt;Cu&gt;Pb&gt;Cd. Therefore, the coastal water from the Panvel creek is polluted by heavy metals. Absence of heavy metals like Pb and Cd is attributed to the waste discharged in the creek are free from these metals and is also beneficial to the coastal biota of the creek. Consistent occurrence of Cu, Ni, Zn, and Hg in Panvel creek should not be ignored considering their impact on the ecosystem and marine biota.

Response of aquatic ecosystems multi-trophic biological communities under multiple pollutants stress

Industrialization has significantly polluted the Yangtze River Basin, posing phenolic compounds and heavy metals that threaten ecological and human health. This study comprehensively evaluated the impact of these pollutants on the Yangtze River's aquatic ecosystems across multiple trophic levels. Sampling from 84 sites during both dry and wet seasons, water chemistry and biological data were analyzed by advanced molecular and statistical techniques. All organisms are divided into three ecological functional groups with a multitrophic level structure based on their co-occurrence. Our results demonstrate pronounced spatial and seasonal variations in pollutant concentrations, with notable sensitivity in ecological structures to phenolic compounds and heavy metals. The ecological impacts of pollutants are more readily observable (up to 43.1 % maximum) when assessing ecological communities based on functional groups with multi-trophic biological community as opposed to traditional taxonomic classifications. All the data used to develop a predictive model for ecological functional groups, achieving an accuracy rate of 86.1 %. This research provides critical insights into the multi-trophic effects of composite pollution, advocates for the adoption of comprehensive multi-trophic evaluation methods in large-scale ecological monitoring and sustainable watershed management globally.

Efficient Elimination of Inorganic/Organic Pollutants by Fe3O4/biochar@sodium Alginate Gel Beads.

The magnetic composite gel bead (Fe3O4-C@SA GB) adsorbent was prepared by sodium alginate (SA) crosslinking with pitaya peel-derived porous carbons (PPDPCs) and magnetic iron oxide nanoparticles (Fe3O4 NPs). The adsorption effects of Fe3O4-C@SA GBs on heavy metal ions (HMIs) and 17 β-estradiol (E2) in water are evaluated by classical kinetic models and isotherm models. The pseudo-second-order kinetic model shows that Fe3O4-C@SA GBs have maximum adsorption capacities of 9.62, 7.50, and 13.61 mg/g for Cu (II), Cd (II), and Pb (II), respectively. Meanwhile, the highest adsorption performance of the synthesized gel beads to E2 is of ca. 276.3 mg/g. In addition, the Fe3O4-C@SA GBs can still maintain a high level of adsorption efficiency after five adsorption cycles, displaying economic efficiency and reusability. Hence, this work provides useful insights into the efficient adsorption elimination of pollutants in sewage and the corresponding adsorption mechanisms.

Z-scheme driven charge transfer in g-C3N4/α-Fe2O3 nanocomposites enabling photocatalytic degradation of crystal violet and chromium reduction

In this study, we demonstrated the design and fabrication of iron oxide-embedded protonated graphitic carbon nitride (α-Fe2O3/p-g-C3N4) nanocomposites for photocatalytic dye degradation and heavy metal reduction applications under sunlight irradiation. The developed nanocomposites, with varying weight percentages of α-Fe2O3, were characterized for their structural (XRD, FTIR, XPS), optical (absorption and photoluminescence), morphological (FE-SEM, TEM), and electrochemical (EIS) properties to elucidate their structure-property relationships. The synthesis method ensures the uniform dispersion of α-Fe2O3 nanoparticles, with a particle size range of 50–60 nm, onto p-g-C3N4. XPS analysis suggests the formation of an electrical layer at the interface of α-Fe2O3/p-g-C3N4, facilitating the formation of a Z-scheme heterojunction. The photoluminescence and EIS spectra of the nanocomposite indicated effective separation and transfer of photo-induced charge carriers, aided by a reduced bandgap energy of ∼2.63 eV. Notably, the optimized 10 wt% α-Fe2O3/p-g-C3N4 nanocomposite exhibited superior photocatalytic activity, degrading nearly 100 % of crystal violate dye and reducing 98 % of Cr(VI) ions, compared to bare p-g-C3N4, which degraded around 43 % of the dye and reduced 39 % of Cr(VI) ions under sunlight irradiation. Scavenger studies indicated that α-Fe2O3/p-g-C3N4 nanocomposites produce adequate superoxide anions and hydroxyl radicals for dye degradation and heavy metal ion reduction. The composite also demonstrated consistent recyclability up to 5 cycles with around 100 % cyclical efficiency. The pH-dependent photoreduction and cyclic dye degradation by the 10 wt% α-Fe2O3/p-g-C3N4 photocatalyst indicated excellent stability, making it suitable for the treatment of multi-pollutant wastewater.

Microplastic-Enhanced Cadmium Toxicity: A Growing Threat to the Sea Grape, Caulerpa lentillifera.

The escalating impact of human activities has led to the accumulation of microplastics (MPs) and heavy metals in marine environments, posing serious threats to marine ecosystems. As essential components of oceanic ecosystems, large seaweeds such as Caulerpa lentillifera play a crucial role in maintaining ecological balance. This study investigated the effects of MPs and cadmium (Cd) on the growth, physiology, biochemistry, and Cd accumulation in C. lentillifera while elucidating the underlying molecular regulatory mechanisms. The results demonstrated that exposure to MPs alone significantly promoted the growth. In contrast, exposure to Cd either alone or in combination with MPs significantly suppressed growth by reducing stem and stolon length, bud count, weight gain, and specific growth rates. Combined exposure to MPs and Cd exhibited the most pronounced inhibitory effect on growth. MPs had negligible impact while Cd exposure either alone or combined with MPs impaired antioxidant defenses and exacerbated oxidative damage; with combined exposure being the most detrimental. Analysis of Cd content revealed that MPs significantly increased Cd accumulation in algae intensifying its toxic effects. Gene expression analysis revealed that Cd exposure down-regulated key genes involved in photosynthesis, impairing both photosynthetic efficiency and energy conversion. The combined exposure of MPs and Cd further exacerbated these effects. In contrast, MPs alone activated the ribosome pathway, supporting ribosomal stability and protein synthesis. Additionally, both Cd exposure alone or in combination with MPs significantly reduced chlorophyll B and soluble sugar content, negatively impacting photosynthesis and nutrient accumulation. In summary, low concentrations of MPs promoted C. lentillifera growth, but the presence of Cd hindered it by disrupting photosynthesis and antioxidant mechanisms. Furthermore, the coexistence of MPs intensified the toxic effects of Cd. These findings enhance our understanding of how both MPs and Cd impact large seaweed ecosystems and provide crucial insights for assessing their ecological risks.

Food safety risk assessment in Vietnam - Current situation and way forward

Risk assessment is an important scientific step in risk-based food safety (FS) management that has been applied in many countries. In Vietnam, despite being regulated by law, risk assessment activities have not been widely implemented due to inadequate attention and limited resources, which reduces its roles in FS management. Several challenges of FS risk assessment in Vietnam are related to institutional organizations, data management, human resources, and the characteristics of the food supply chain. This article aims to review the progress of risk assessment activities in Vietnam. Different risk assessments have been conducted for various chemical hazards such as pesticides, mycotoxins, preservatives, heavy metals, and environmental residuals, whereas fewer risk assessments have been implemented for microbial hazards, which were mainly focused on common food poisoning pathogens, like Salmonella, Staphylococcus aureus, and E. coli. This article also analyzes risk assessment models from countries and regions such as China, Japan, the United States, Europe, and ASEAN in order to identify the issues and challenges in Vietnam. Based on the review and analysis, we recommend that Vietnam take action to implement risk assessment activities as a tool for effective FS management.

Leaching behavior of sustainable concrete made with coal ash wastes as replacement of cement and sand.

The coal-fired power plant fly ash (FA) and bottom ash (BA) are gradually used as alternative materials in the concrete. However, knowledge of the leaching characteristics of using both incinerator ashes in concrete production is lacking. This work aimed to evaluate the leaching behavior of the FA and BA used in concrete production by employing batch and tank leaching tests. The outcomes of both leaching tests showed that there was no considerable leaching of any trace elements to the environment, and it remains much lower than standard limitations for utilization as construction materials. The results of cumulative mass discharge showed that the slope of flux time for all elements was less than 0.4 and because of that, primary surface wash-off was the main discharge process of all the heavy metals. Strength test results revealed that there was not much difference between coal ash concrete (CAC) and the control mix at the initial age of curing time. Despite that, at a long period of curing time (180 days), the compressive strength of CAC containing 20% FA as cement replacement and 100% BA as fine aggregate replacement increased by 76% due to the pozzolanic reaction of BA and FA in comparison to the normal concrete, while, due to the high porosity of BA, the workability of CAC decreased by 50%. The outcomes of the current work revealed that the combined use of FA and BA can be counted as a promising alternative in the production of sustainable concrete for structural applications toward sustainable development.

Metallothionein family genes in kiwifruit: characterization and determining their roles in plant’s response to different stresses

Kiwifruit growth and development are severely affected by various biotic and abiotic stresses, especially cold stress and the bacterial disease caused by Pseudomonas syringae pv. actinidiae (Psa). Metallothioneins (MTs) are a group of cysteine-rich proteins that play crucial roles in stress response, metal detoxification, and homeostasis in plants. However, the protective role of these MTs in kiwifruit remains to be elucidated. In the present study, four AcMT genes were identified in the Hongyang kiwifruit genome, namely, two Type 2 isoforms (AcMT2 and AcMT2a) and two Type 3 isoforms (AcMT3a and AcMT3b) located separately on four different chromosomes. The hormones and stress response cis-elements within the promoter regions of these AcMTs were characterized. It was revealed that the four AcMT genes exhibited different expression patterns in different tissues: AcMT2 and AcMT2a were expressed at much higher levels in the fruit, male flower, female flower, root, and bark, while AcMT3a was expressed mainly in the fruit and AcMT3b was expressed highly in the bark. The expression patterns of these AcMT genes after exposure to Psa infection and different phytohormones, including gibberellic acid A3(GA3), ethylene (ET), and abscisic acid (ABA), were evaluated. It was revealed that in response to Psa infection, the main AcMTs in each tissue (those with expression levels higher compared to the other MTs in that tissue) were downregulated during the early stage in kiwifruits, followed by a recovery phase. In addition, most AcMTs were downregulated after exposure to ET and GA3, while type 2 AcMTs (AcMT2 and AcMT2a) were upregulated after treatment with ABA. The overexpression of AcMTs in Escherichia coli presented a higher tolerance to H2O2, heavy metals, low temperature, and high temperature. Collectively, these findings demonstrated the protective roles of AcMTs in terms of stress resistance conferred through plant hormone-related signal pathways.

Application of melting technology in the treatment of nonferrous hazardous waste residues

ABSTRACT In order to find a more effective treatment method for non-ferrous hazardous waste residues, the research proposed the fusion disposal technology of collaborative resource residues. The empirical results showed that the leaching concentrations of Cr and Pb of the molten products of the resource residue were maintained at 0 mg/L, and the final leaching concentrations of most heavy metals were within 0.10 mg/L, which showed low toxicity to the environment. The above results show that the fusion disposal technology of collaborative resource residue is an effective treatment method. The fusion disposal technology not only reduces the heavy metal leaching concentration of non-ferrous metals, but also promotes the development of hazardous waste residue treatment technology.

Exploring the Possibilities of Using Recovered Collagen for Contaminants Removal—A Sustainable Approach for Wastewater Treatment

Collagen is a non-toxic polymer that is generated as a residual product by several industries (e.g., leather manufacturing, meat and fish processing). It has been reported to be resistant to bacteria and have excellent retention capacity. However, the recovered collagen does not meet the requirements to be used for pharmaceutical and medical purposes. Due to the scarcity of water resources now affecting all continents, water pollution is a major concern. Another major field that could integrate the collagen generated as a by-product is wastewater treatment. Applications of collagen-based materials in wastewater treatment have been discussed in detail, and comparisons with already frequently used materials have been made. Over the last years, collagen-based materials have been tested for removal of both organic (e.g., pharmaceutical substances, dyes) and inorganic compounds (e.g., heavy metals, noble metals, uranium). They have also been tested for the manufacture of oil-water separation materials; therefore, they could be used for the separation of emulsified oily wastewater. Because they have been analysed for a wide range of substances, collagen-based materials could be good candidates for removing contaminants from wastewater streams that have seasonal variations in composition and concentration. The use of recovered collagen in wastewater treatment makes the method eco-friendly and cost efficient. This paper also discusses some of the challenges related to wastewater treatment: material stability, reuse and disposal. The results showed that collagen-based materials are renewable and reusable without significant loss of initial properties. In the sorption processes, the incorporation of experiments with real wastewater has demonstrated that there is a significant competition among the substances present in the sample.

Oxidative Processes and Xenobiotic Metabolism in Plants: Mechanisms of Defense and Potential Therapeutic Implications.

Plants are continuously exposed to environmental challenges, including pollutants, pesticides, and heavy metals, collectively termed xenobiotics. These substances induce oxidative stress by generating reactive oxygen species (ROS), which can damage cellular components such as lipids, proteins, and nucleic acids. To counteract this, plants have evolved complex metabolic pathways to detoxify and process these harmful compounds. Oxidative stress in plants primarily arises from the overproduction of hydrogen peroxide (H2O2), superoxide anions (O2•-), singlet oxygen (1O2), and hydroxyl radicals (•OH), by-products of metabolic activities such as photosynthesis and respiration. The presence of xenobiotics leads to a notable increase in ROS, which can result in cellular damage and metabolic disruption. To combat this, plants have developed a strong antioxidant defense mechanism that includes enzymatic antioxidants that work together to eliminate ROS, thereby reducing their harmful effects. In addition to enzymatic defenses, plants also synthesize various non-enzymatic antioxidants, including flavonoids, phenolic acids, and vitamins. These compounds effectively neutralize ROS and help regenerate other antioxidants, offering extensive protection against oxidative stress. The metabolism of xenobiotic substances in plants occurs in three stages: the first involves modification, which refers to the chemical alteration of xenobiotics to make them less harmful. The second involves conjugation, where the modified xenobiotics are combined with other substances to increase their solubility, facilitating their elimination from the plant. The third stage involves compartmentalization, which is the storage or isolation of conjugated xenobiotics in specific parts of the plant, helping to prevent damage to vital cellular functions. Secondary metabolites found in plants, such as alkaloids, terpenoids, and flavonoids, play a vital role in detoxification and the defense against oxidative stress. Gaining a deeper understanding of the oxidative mechanisms and the pathways of xenobiotic metabolism in plants is essential, as this knowledge can lead to the formulation of plant-derived strategies aimed at alleviating the effects of environmental pollution and enhancing human health by improving detoxification and antioxidant capabilities, as discussed in this review.

1D supramolecular assembly-induced emission and colorimetry toward precise onsite mercury(II) detection

Manipulation of the one-dimensional (1D) supramolecular assembly of platinum(II) terpyridyl complex is promising for achieving precise onsite mercury(II) detection in complex environments, but still challenging. Herein, by systematic molecular design of platinum(II) terpyridyl complex, chloride-mediated 1D supramolecular assembly has been successfully achieved, exhibiting not only improved recognition ability but also dual-visual signal, with turn-on red luminescence and high-contrast color change from pale-yellow to orange-red. The probe also shows excellent selectivity and anti-interference properties, fast response rate (< 1 s) and low detection limit, stretching to 20.6 fg when incorporated in a hydrogel matrix. Structure insight for the dual-visual response shows that this high detection performance derives from the ancillary ligand of -NCS, which endows the increase of ion-association ability between platinum(II) terpyridyl complex and [HgCl4]2−, leading that 1D packing mode with strengthened Pt-Pt interactions. In all, this work highlights a new strategy of 1D supramolecular assembly construction for high performance detection of heavy metal ions.

Clean-up of wastewater discharged from zinc industry through application of zeolite 4A produced from a waste contaminated by lubricant oil components

The zeolite 4 A powders were sustainably derived from clay-based waste contaminated with the spent lubricant oil. Then, the products were used to treat the wastewater discharged from a local zinc industry. The main challenge is removal of toxic organic components from the waste and conversion of obtained precursor to the zeolite structure, simultaneously. The variation in crystallinity was studied as a function of composition, fusion temperature, aging, and recrystallization times. The zinc adsorption was found to be markedly dependent not only on sodium carbonate/waste ratio but also on aluminum hydroxide content. However, pronounced adsorption was observed over the particles fabricated through the fusion at 900 °C. The relative crystallinity, ∼32 %, is crucial for the effective immobilization of heavy metal ions like Cd2+, Ni2+, and Zn2+ from the wastewater. This level of crystallinity is achievable with the control of aging and recrystallization times, both in 3 h. The maximal zinc adsorption capacity, ∼143 mg g−1, was obtained for the particles with large pores, 48 nm, facilitating the ion diffusion into the adsorbent. On the other hand, the appropriate electrical charge surface expressed based on zeta potential, −43 mV, provided a proper condition for the electrostatic adsorption.

The roles of nanoparticle-enriched biochars in improving soil enzyme activities and nutrient uptake by basil plants under arsenic toxicity

Enriched biochar with improved properties and functionality can play a significant role in providing sustainable solutions for mitigating heavy metal contamination in soil. In this experiment, the effects of solid and enriched biochars (potassium-enriched biochar (BC-K), magnesium-enriched biochar (BC-Mg), both individually and combined) were examined on soil microbial and enzyme activities, as well as nutrient uptake by basil plants cultivated in a soil with three levels of arsenic (nontoxic, 50 mg As kg−1 soil, and 100 mg As kg−1 soil). Biochar-related treatments, increased soil organic matter (65–76%), while decreased availability of arsenic (6–55%) in the soil. The microbial biomass carbon (by about 123%) and soil basal respiration (by about 256%), and soil enzymatic activities (β-glucosidase, urease, alkaline phosphatase, and dehydrogenase) were enhanced by enriched biochars under arsenic toxicity. The solid and particularly enriched biochars decreased arsenic content and improved nitrogen and phosphorus contents of roots and shoots, root length, root activity, and root and shoot biomass in basil plants. Therefore, it is conceivable to suggest that enriched biochars are superior treatments for improving nutrient absorption rates and basil growth under arsenic toxicity through decreasing arsenic mobility and increasing soil microbial activities.