Heavy Metals Nickel Research Articles

Outdoor exposure of a heavy metal doped concrete -Measuring and modelling of substance release.

Many construction products are in contact with, e.g., rain and seepage water during their service life. As a result, they may leach and release potentially harmful substances into the environment. Harmonized laboratory tests are available to assess the potential environmental impact, but the evaluation of leaching test results remains challenging because releases found in laboratory experiments cannot be directly extrapolated to field conditions. Particularly complex is the case of irrigated and therefore intermittently wetted components. This paper presents the leaching results of a one-year outdoor irrigation of a fly ash concrete doped with heavy metals (arsenic, lead, cadmium, chromium, copper, nickel, thallium, vanadium, and zinc). The results are compared with those of two other outdoor irrigation studies: a high-density concrete and a facing masonry mortar. Two modeling approaches, a statistical method by Weiler et al. and a thermodynamic model of Vega Garcia et al. are used to model the incremental and cumulative releases and to compare their applicability and predictive value. The experimental data of this work confirm the well-known fact that cementitious phases effectively incorporate many potentially environmentally harmful substances. However, increased leaching, particularly outdoors, is observed for the oxyanion-forming elements arsenic, chromium, vanadium, and sulfur. Both models seem sufficient for depicting and, in the case of statistics, also to predict the magnitude of the measured values. However, while the statistical approach focuses only on the results and requires further verification data and factor development for different materials, the thermodynamic approach describes the geochemical processes and therefore requires more background knowledge of the operator; it also lacks predictive accuracy for the irrigation case. Further research is needed.

Evaluation of energy recovery, pollutant removal, and microbial dynamics in aged refuse bioreactor for landfill leachate treatment

The study evaluates the effectiveness of aged refuse bioreactors (ARBs) in treating young landfill leachate and recovering energy through biogas production. Over 90 days, duplicate reactors (ARB1 and ARB2) were operated through three 30-day recirculation cycles under anaerobic conditions, utilizing aged refuse from a closed landfill in Bangalore, India. The study was extended by an additional 900 days without further leachate addition to assess long-term gas generation potential. Cumulative gas production amounted to 1384 L in ARB1 and 1182 L in ARB2, with maximum methane production per gram of chemical oxygen demand (COD) recorded at 0.474 L and 0.387 L, respectively. Variability in biogas production was correlated with differences in volumetric moisture content, which also influenced pollutant removal and led to significant improvements in the leachate pollution index, decreasing from 24.4 to 12.84 in ARB1 and to 16.46 in ARB2. COD levels were decreased by 70–90%, and TDS by 46–63%. Heavy metal concentrations, including copper, chromium, cadmium, lead, zinc, and nickel, were reduced by 95–99% to acceptable levels, though increases in ammonia and total phosphorus were noted. Key mechanisms in the ARB included anaerobic degradation, adsorption, oxidation-reduction reactions, and precipitation. In the fourth cycle, without leachate recirculation, gas production reached 320 L in ARB1 and 358.8 L in ARB2, indicating effective conversion of carbon retained from aged refuse and leachate treatment into biogas. Microbial analysis identified dominant communities of Methanosarcina and Methanomicrobia. Overall, this study demonstrates that ARBs are effective in treating young landfill leachate and recovering energy, offering insights into sustainable waste management.

Environmental degradation of Nike lake: a study on water quality parameters and heavy metal accumulation in fish

Environmental pollution is a pressing global issue, with heavy metal pollution posing a significant threat. This study examined the concentrations of heavy metals (cadmium, nickel, lead, chromium, manganese, iron, zinc, copper, mercury, selenium, and arsenic) in various organs and tissues (blood, gills, intestines, liver) of African Catfish (Clarias gariepinus) and Redbelly Tilapia (Tilapia zillii) from Nike Lake in Enugu State, Nigeria. Water samples from the lake were also analyzed for heavy metal concentrations, as well as nitrogen and phosphorous content, nitrate, phosphate, and dissolved oxygen levels. The results showed that the fish samples contained varying concentrations of heavy metals, with the highest levels found in the gills. The ranges of metal concentrations were: Cd (0.00-0.033), Ni (0.00-0.002), Pb (0.00-0.072), Cr (0.00-0.039), Mn (0.00-0.041), Fe (0.010-1.363), Zn (0.268-0.604), Cu (0.008-0.084), Hg (0.00-0.147), Se (0.293-0.474), Mo (0.020-0.095), and As (0.00-0.034). The water samples contained similar concentrations of heavy metals, were Cd:0.02, Ni:0.001, Pb:0.034, Cr:0.00, Mn:0.012, Fe:0.037, Zn:0.173, Cu:0.008, Hg:0.147, Se:0.309, Mo:0.027, As:0.004, with the addition of nitrate (4.373), phosphate (4.383), and dissolved oxygen (45.33) levels. The nitrogen and phosphorous content in the fish organs ranged from 2.938-4.987 and 3.089-7.484, respectively. The study highlights the presence of toxic heavy metals in the organs of the fish, emphasizing the need for regulation and monitoring to mitigate the risks associated with heavy metal pollution in aquatic ecosystems.

Organic compounds in valley fogwater in North and Mount Lebanon during COVID-19 period.

Caltech Active Strand Cloudwater collectors are used to collect valley fog samples from Mount and North-Lebanon during 2021 for the speciation of organic matter for the first time ever. Numerous compounds including pesticides, phenols, acids, and persistent organic pollutants such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons (PAHs) have been identified in fogwater samples. They are extracted using the liquid-liquid extraction performed on the XTR chromabond columns. The highest contribution to the total organic fraction refers to phenols and acids (around 77%) due to their better water solubility than others inducing a good affinity to the aqueous phase of fogwater droplets. The lowest contribution refers to the hydrophobic families accounting together for <5% of the total fraction. Pearson analysis is employed in this study to check correlations between some variables. PAHs are found to be originated from combustion and vehicle exhaust and PCBs are found to be highly correlated with PAHs. Phenols and acids are highly associated with PAHs and PCBs as well as with sulfate and heavy metals (manganese and nickel). This shows that their sources can be either atmospheric oxidation or vehicle exhaust. Pesticides are found to be highly correlated with each other which suggests their simultaneous applications. Despite all, more research is still needed to have a bigger and more reliable data to adopt the beneficial effect of fogwater as an alternative for fresh water at least for the Lebanese agriculture.

Promising strains of phosphate-mobilizing rhizobacteria resistant to glyphosate and nickel

A search was carried out for phosphate-soluble rhizobacteria capable of growing in the presence of different concentrations of the herbicide glyphosate and nickel heavy metal ions (Ni2+). Using the Muromtsev medium, the phosphate-mobilizing activity was determined only in 3 out of 20 strains of Rhizobium spp. – with a low solubilization index (IS). On the contrary, all strains of Pseudomonas sp. showed a positive result, and the highest IS was in Pseudomonas sp. OBA 2.4.1 and GOR 4.17. The highest growth activity under stressful conditions was shown by 4 strains of Pseudomonas spp.: OBA 2.4.1, OBA 2.9, 4.17 and STA 3, their growth was noticeably inhibited with an increase in the concentration of glyphosate in the medium to 10.0 mg/ml. The growth activity of Rhizobium spp. strains was characterized as average. When growing on a medium with NiCl2, Pseudomonas strains sp. 65 HM and 67 HM grew to a concentration of 9 mM NiCl2 in the medium, at a concentration of 11 mM, strain 67 HM gave growth in the form of single colonies. These strains were isolated from soil samples taken from sites contaminated with chemical effluents. It is possible that nickel chlorides were already present in such soil in high concentrations exceeding the norm, that is why these strains had such high resistance to nickel ions. Thus, Rhizobium sp. strains did not have the most active PGPR properties, but different strains of Pseudomonas sp. showed high resistance to glyphosate and nickel chloride. Thus, Pseudomonas sp. they demostrated their high ability to adapt to stressful conditions. It is such PGPR bacteria (Plant Growth Promoting Rhizo bacteria) that can be considered as biological agents to increase the efficiency of bioremediation of agricultural soils.

An interplay of salt and Ni stress on contrasting tomato (Solanum lycopersicum L.) genotypes: a physiological and biochemical insight

The concurrently occurring multiple abiotic stresses like salinity and heavy metals (Nickel) pose a serious threat to plant survival and food security worldwide, especially in the face of climate change. Therefore, it is imperative to continuously test and study the plant’s physiological changes under combinations of abiotic stresses to ensure sustainability and food security. An experiment was conducted to study the interactive effects of salinity (0, 7.5, and 15 dS m−1) and Ni toxicity (0, 10, 20, and 40 mg kg−1) on a tolerant (Naqeeb) and a sensitive (Nadir) Solanum lycopersicum L. physiology and fruit quality in the soil. At maturity (50% fruit ripening), the plant growth and physiological characteristics were measured, revealing that the tolerant genotype exhibited the higher values for plant height, dry weight, potassium, membrane stability index (MSI), and antioxidant enzymes (superoxide dismutase; SOD, catalase; CAT, ascorbate peroxidase; APX, and glutathione reductase; GR). Additionally, it showed enhancement in fruit yield, size, and quality. Conversely, the tolerant genotypes showed a lower reduction in terms of plant height (25.4%) and plant dry weight (41.9%) compared to sensitive genotype (30.1 and 51.4%, respectively). Additionally, the tolerant genotype demonstrated lower values of Ni and Na+ concentration and MDA accumulation under the combined stress of salt and Ni, compared to the sensitive genotype. Furthermore, the study indicated that Ni at a concentration of 10 mg kg−1 significantly influenced tomato plant growth by enhancing its nutritional efficiency and competing with Na+. However, Ni at concentrations of 20 and 40 mg kg−1 had toxic effects on the plants, leading to a decrease in plant growth and physiological processes. Moreover, a negative relationship was observed between Ni uptake and Na+ uptake, while a positive relationship was observed between Ni and K+ uptake. Overall, this study provides valuable insights into the interaction between salinity, heavy metal toxicity, and tomato plant physiology, contributing to the development of sustainable agricultural practices.

Pertubations of Physicochemical Properties and Heavy Metal in the Soil of Coastal Areas of Akwa Ibom State, Nigeria

This study aimed at assessing the concentrations and perturbations of the physicochemical properties and heavy metals in the soil of the coastal regions of Akwa Ibom State, Nigeria. Sampling was carried out across three mangrove locations (Iko Town, Okoroutip and Uta Ewa) in Eastern Obolo, Ibeno and Ikot Abasi Local Government Areas respectively. Four vegetation plots were randomly selected, and within each plot, three belt transects were established. Physicochemical properties [Sand, Clay, Silt, organic carbon (OC), total nitrogen, sulphate and chlorine content] and heavy metals (Arsenic, Silver, Chromium, Copper, Nickel, Lead, Mercury, Cadmium, Titanium, Vanadium and Zinc) were analyzed using standardized methods. Results from this study revealed considerable variations in the physicochemical properties of soil in the study area. The aforementioned heavy metals were present in both wet and dry seasons in considerable concentrations in the soil samples within the study areas. However, were within and below WHO limits. The variations in the physicochemical properties and the presence of these heavy metals in the samples are indicative of an impacted environment unsuitable for the growth and survival of the endemic flora and fauna species of this unique ecosystem. In view of the current knowledge of the role of mangrove ecosystems in blue-economy of the nation and mitigation of ongoing climate change, we advocate a tripartite alliance between the government, multinational companies operating within the area and the various impacted communities that leads to a concerted efforts of constant monitoring and remediation in the reduction of current and future pollutant levels.

Synthesis of Dispersed Magnetic Fe3O4 Nanohydrogel Based on Gelatine by Gamma Irradiation for Toxic Heavy Metals Removal

AbstractHeavy metals are among the problematic groups of contaminants. They are discharged from various industries. The wastewater disposed by heavy metals is causing major hazards to the environment. Different hydrogels based on Gelatin (gelt/AAm/EDTA) and nano- (Fe3O4/gelt/AAm/EDTA) were prepared by gamma radiation at 60 KGy and employed for heavy metals elimination. The structure and surface morphology of the manufactured hydrogels were confirmed with FTIR, X-ray, surface area, and SEM. The prepared hydrogels were characterized in terms of their gel content. The swelling properties were studied as a function of time. This research aims to investigate the adsorption properties of diverse hydrogels concerning heavy metal ions, specifically copper, cobalt, and nickel. The impact of key experimental factors, including initial metal concentration, temperature, time, and pH, was inspected via batch adsorption experiments utilizing atomic absorption spectroscopy. It was found that the adsorption of Cu+2‏, Co+2‏ and Ni+2‏ ions is pH-dependent, and the optimal pH for adsorption of Cu+2 is pH 4‏, Co+2 ‏is 5, and Ni+2‏ is 4. The highest metals removal was copper, nickel, and cobalt ions by nano (Fe3O4/gelt/AAm/EDTA) hydrogel with removal percent 98.5% for Cu+2, 96.8%for Ni+2, and 93.9%for Co+2. Graphical Abstract

Assessment of physicochemical properties among petroleum contaminated and normal soil: A multivariate statistical analysis

Soil surveying and mapping are vital operations in soil science. They contribute to the evaluation of changes in soil quality between various geographical regions. This study intended to investigate the effect of geographic variability on soil properties gathered from different geographical areas of the Rajasthan State of north-western India, using conventional analytical methods. Normal and petroleum-contaminated soils were collected from four diversified regions of Rajasthan: namely, hyper saline wetland (Sambhar), arid desert region (Jaisalmer), semi-arid region (Ganganagar) and humid irrigated plains (Banswara). The correlations between normal and contaminated soil for these four stations were investigated using multivariate analyses, principal component analysis (PCA) and statistical quality control. The one-way ANOVA test is applied to determine the statistical significance between different sampling stations for both normal and contaminated soil. Since the p-value in both cases is less than 0.05, it reflects a significant difference in physical properties among all four stations. The PCA analysis suggests that the first three components have Eigen values greater than one that can describe 100% of the total variability in soil properties. Heavy metals (Lead, Nickel and Copper) are the primary measures of variability between sample points for contaminated soil. In contrast, physicochemical properties (pH, Conductivity and Sodium) are the primary measures of variability between sample sites for normal soil.

Measurements of Heavy Elements and Radioactivity Concentration Levels in Types of Fertilizers and Pesticides Commonly Used in Sana’a Yemen

This study aims to measure heavy metals (HMs) concentration and radioactivity concentration levels in fertilizer and pesticide samples collected from local markets in Sana’a, Yemen. Gamma spectroscopy employing a Survey Sodium Iodide NaI (TI) RIIDEYM-G detector was used for radiation and dose assessments. As for heavy metal analyses, this study used Inductively Coupled Optical Emission Spectroscopy (ICP-OES). Thirty samples were collected from local markets in Sana’a, Yemen. Radioactivity measurements show low levels of radioactivity concentration. The average dose rates due to fertilizer and pesticide samples were 1.14 and 1.07 mSv/y, respectively. These values are nearly equal to the recommended annual radiation dose rate limit (1mSv/y) recommended by the International Commission on Radiological Protection (ICRP). For heavy metal analysis, it was found that the average concentrations of heavy metals (HMs) (cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn)) in the fertilizer samples were 1.08 mg/kg, 4.944 mg/kg, 13.8495 mg/kg, 274.371 mg/kg, 3.30446 mg/kg, 15.35686 mg/kg, and 24.4547 mg/kg, respectively. Heavy metal concentrations in fertilizer samples were mainly less than European (EU) guideline limits, with the exception of a few samples. The average concentrations of heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, and Zn) in the pesticide samples were 0.8 mg/kg, 0.5784 mg/kg, 52.280 mg/kg, 73.4651 mg/kg, 2.4482 mg/kg, 3.199 mg/kg, and 1.1309 mg/kg, respectively. The heavy metal concentrations in pesticide samples were less than the corresponding values in fertilizer samples.

Determination of heavy metals and health risk assessment in drinking water in Bukayriyah City, Saudi Arabia

Abstract Heavy metal levels, including arsenic, lead, cadmium, mercury, chromium, and nickel, were analyzed in 124 samples of tap and filtered water obtained from Bukayriyah city, Saudi Arabia, using inductively coupled plasma mass spectrometry. Additionally, measurements of total dissolved solids, conductivity, and pH were also performed. The study also evaluated the potential non-cancer and cancer risks (CRs) associated with the ingestion of these heavy metals for both children and adults. The results indicated that the average concentrations of heavy metals in both tap and filtered water were found to be below the recommended limits set by the World Health Organization and the Gulf Standard Organization. To assess the non-carcinogenic risks, the chronic daily intake (CDI), hazard quotient (HQ), and hazard index were calculated for analyzed metals present in both tap and filtered water. In both the children and adult populations, the CDI indices for heavy metals in tap and filtered water followed the order of Cr &gt; Hg &gt; Ni &gt; Pb &gt; As &gt; Cd. However, it is worth noting that the CDI values for tap water were higher than those for filtered water for both children and adults. The descending order of HQ values is as follows: Hg &gt; Cr &gt; As &gt; Cd &gt; Pb &gt; Ni. This indicates that the HQ values for all metals are below the acceptable limit of 1. These findings confirm that the exposure to the examined metals from both tap and filtered water in Bukayriyah City is within safe limits and poses no non-carcinogenic risks. To assess the carcinogenic risks, the incremental lifetime cancer risk (ILCR) and total carcinogenic risk (TCR) were calculated. The order of ILCR values for both children and adults in tap and filtered water is as follows: Ni &gt; Cr &gt; Cd &gt; As &gt; Pb. All ILCR values were below the acceptable limit of 10−6 to 10−4. However, TCR values exceeded this threshold range only for children exposed to tap water, with a value of 1.43 × 10−4. Thus, children exposed to tap water have a potential risk of developing carcinogenic diseases.

Machine learning-assisted risk evaluation of heavy metals in the Hainan gold mining region, China.

This study employed machine learning (ML) to thoroughly investigate the impact of informal mining activities on the distribution and pollution status of heavy metals in soils near private gold mines in Hainan Province, southern China, a region known for its ecological sensitivity and economic importance. By systematically collecting surface soil samples and samples at depths of 0.5-1m from 175 drilling sites, a comprehensive quantitative analysis was conducted on major heavy metal elements, including lead (Pb), copper (Cu), cadmium (Cd), nickel (Ni), mercury (Hg), chromium (Cr), arsenic (As), and zinc (Zn). Combined with evaluation methods such as the Pollution Load Index (PLI), Normalized Pollution Index (NIPI), and Ecological Risk Index (ERI), the study revealed a high level of soil pollution at informal mining sites. The findings indicated that the average concentrations of Pb, Cd, Hg, As, and Zn in surface soils significantly exceeded the background values for soils in China, with a pronounced positive correlation observed between these heavy metal elements in both surface and deep soil profiles (r > 0.5). Furthermore, leveraging the heavy metal content in surface soils and the constructed environmental indicators, the predictive accuracy for metal content in deep soils was found to range from R2 = 0.27 to 0.68, suggesting that informal mining activities have led to substantial variations in metal content across different soil profiles. Through the application of a random forest model for predictive analysis of the PLI, NIPI, and ERI, high prediction accuracy was achieved (R2 = 0.78, 0.86, and 0.60, respectively). The study demonstrates that informal mining activities not only elevate the risk of soil pollution but also alter the distribution patterns of heavy metals. Also, this study provides a crucial foundation for the scientific assessment of soil quality and potential environmental hazards, while also affirming the efficacy of ML techniques in forecasting soil quality parameters.

Mycosynthesis of TiO2 nanoparticles using Aspergillus penicillioides for toxic metal removal and photocatalytic applications

Globally, heavy metal pollution, especially lead and nickel, is becoming a problem and is of great concern due to its adverse effects. This study focuses on the eco-friendly biosynthesis of TiO2 nanoparticles using Aspergillus penicillioides metabolites as capping and reducing agents. The myco-synthesized TiO2 nanoparticles were characterized as oblate spherical and applied for photocatalytic removal of lead and nickel from industrial effluent. Optimal conditions for removal included lead and nickel concentrations of 60 μg/mL and 2 μg/mL, 10 μg/mL TiO2 nanoparticle concentration, a pH of 6, and sunlight irradiation. The kinetics and isotherm of adsorption were explained. Effective degradation of lead and nickel by using TiO2 nanoparticles was confirmed by atomic absorption spectroscopy. The nanoparticles demonstrated effective photocatalytic degradation of crystal violet dye achieved a high of 86.9% in 4h and 25% in 2 h, respectively, and showed promising biological activities, including antibacterial, antioxidant, and protein leakage properties. The hemolytic assay confirmed their ecological sustainability for bioremediation. The study highlights the effectiveness of new bio-based TiO2 nanoparticles arbitrated by Aspergillus penicillioides as effective bioremediation agents.

Heavy Metals Analysis of Breweries Effluent used in Soil Cultivated with Glycine Max (L.) Merr. Accessions with Biochar Augmentation

Beer production has promulgated the prevalence of heavy metal contamination in the environment (soil and water bodies). The magnitude of breweries wastewater-effluent effect discharged on soil and its effect on crop quality in terms of growth and physiology must therefore be investigated. This study aims to assess the level of seven heavy metals (HM) (lead (Pb), nickel (Ni), chromium (Cr), copper (Cu), cadmium (Cd), zinc (Zn) and iron (Fe)) in breweries wastewater-effluent and its effect on the growth of Glycine max accessions (TGM-3990, TGM-1348, TGM-1732, TGM-2175 and TGM-928) as well as the influence of biochar soil amendment in the induction of HM tolerance in G. max. Effluent properties were analyzed using the A1 portable TDS/EC meter. HM in the wastewater-effluent was determined using Atomic Absorption Spectrometer (AAS). The experiment was set up in a complete block design. 3 seeds G. max accessions were planted in 7kg of sterilized soil (control, effluent and biochar treatments). Growth parameters were taken using standard methods, while the total photosynthetic pigments (TPP) were determined using the atLeaf chlorophyll meter. The wastewater-effluent recorded an electrical conductivity (EC) of 928µS/cm, total dissolved solids (TDS) (464ppm), Temperature (31.9-32.6°C) and pH (5.37). Results for HM concentration showed; Pb (0.20mg/L), Ni (&lt;0.001mg/L), Cr (0.03mg/L), Cu (&lt;0.001mg/L), Cd (&lt;0.001mg/L), Zn (&lt;0.001mg/L) and Fe (8.74mg/L). The trend shows that Fe˃Pb˃Cr˃Cd˃Cu˃Ni˃Zn. Cr, Cd, Cu, Ni and Zn were significantly below the World Health Organization (WHO) and Waste Water Forum (WWF) permissible limit, while Fe and Pb significantly higher. G. max accessions TGM-928 (80%) and TGM-3990 (80%) had better germination percentage (GP), TGM-1348 (60%) had the lowest GP, while TGM-2175 recorded no germination in all treatments. At 6 weeks after planting (WAP), it was observed that irrigation of G. max accessions with breweries wastewater-effluent significantly (p=0.001) stimulated growth parameters such as shoot length for TGM-3990 which recorded; Treatment=19.53±0.94cm; Control=17.10±0.67cm; Biochar=40.83±1.01cm) while TGM-1732 had the highest shoot growth (T=38.57±1.53cm; C=25.00±0.00cm; B=82.33±5.70cm) when compared to their controls. TGM-3990 (T=32.20mg/kg, C=34.10mg/kg, 43.30mg/kg) recorded the least TPP contents, while TGM-928 (T=51.00mg/kg, C=45.60mg/kg, B=43.50mg/kg) recorded the highest TPP in all treatments. Amelioration of soil with biochar significantly (p=0.001) stimulated growth above the effluent treatment and control. Similar trend was observed for leaf area, petiole length, leaf number, stem girth and internode length. This study has shown that breweries effluent has the potential of growth enhancement in G. max cultivation and in combination biochar application reduces the need for additional fertilizer application.

Characterization and potential application of microspheres from sodium alginate cross-linked with pectin from Citrus depressa Hayata’s peels

BackgroundPectin from Taiwan Citrus depressa Hayata’s peels (CDH pectin) and sodium alginate (Na alginate) were mixed in neutral acidity to produce microhydrogel beads or microspheres. The potential use of the microspheres such as encapsulation materials for quercetin and nobiletin, DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity, toxic elements absorption ability, and thermal characteristics were explored.ResultsDifferent ratios of CDH pectin and Na alginate produced microspheres of varying sizes and shapes. The highest yield (47.59%) with the broadest diameter was obtained at a Na alginate—CDH pectin ratio of 2:1, while the smallest yield was obtained from Na alginate—CDH pectin ratio of 1:3 (24.13%). Increasing the amount of Na alginate resulted in more spherical microspheres, higher heavy metals (cobalt and nickel) removal rates, yet a lower swelling ratio. A high pectin concentration also increased the encapsulation efficiency of quercetin and nobiletin, reaching 91.5% and 86.74%, respectively. Quercetin and nobiletin release analysis (in vitro) showed a slow release of drugs from the microspheres. Less than 20% quercetin and nobiletin were released from the microspheres in SGF (simulated gastric fluid) pH 1.2 solution after 2 h and more than 40% of the encapsulated drug was released in SIF (simulated intestinal fluid) pH 6.8 after 4 h. The strong DPPH scavenging activity of quercetin (99%) was not hindered by encapsulation materials. ICP-OES (inductively coupled plasma–optical emission spectrometry) analysis demonstrated that the biopolymer can absorb cobalt and nickel from water. Thermogravimetric analysis (TGA) result showed that the combination of CDH pectin and Na alginate produced a biopolymer that exhibited a weight loss of only 1.86–4.33% at 100 °C.ConclusionsThese findings suggest that microspheres produced from CDH pectin cross-linked with sodium alginate had potential in nobiletin and quercetin encapsulation. Moreover, the polymer could absorb heavy metals and exhibit an important characteristic for hot food and beverage packaging applications.

Amidation modified hollow composite microspheres as a self-floating adsorbent for efficient capture of anionic dye DB86 and heavy metal nickel (II).

The co-contamination of dyes and heavy metal ions often used as mordants poses potential risks to environment and public health, and is a challenging problem that needs to be solved in water treatment. Meanwhile, improving the solid-liquid separation capability of adsorbents is of great significance for the application of adsorption technology. Herein, amidation modified hollow composite microspheres were prepared using hollow glass microsphere (HGM) as matrix through hydrolysis and condensation of silane coupling agent (A-1100) and subsequent amidation reaction. The material (HGMNE) not only exhibited good adsorption performance for DB86 and Ni2+ but also had stable self-floating capability. The adsorption of DB86 by HGMNE is mainly carried out by the electrostatic interaction between positively charged quaternary amine nitrogen and negatively charged DB86, while the adsorption of Ni2+ is achieved by the carboxyl group in EDTA group through complexation interaction to adsorb Ni2+ to form Ni complex. This research not only is devoted to the utilization of HGMNE to achieve the co-removal of DB86 and Ni2+ and flexible self-floating solid-liquid separation but also verifies the feasibility and applicability of the modification method of introducing organic adsorption functional groups through amidation reaction, so as to expand the preparation path of HGM-based adsorbents.

Biomonitoring of Selected Heavy Metals Using House Sparrow (Passer Domesticus) Residing in Tehran, Iran

he present study aimed to determine the concentration of heavy metals (lead, cadmium and nickel) in the external and internal body tissues of house sparrow (Passer domesticus) living in Tehran, Iran, as a biological monitoring and also to identify possible sources of these pollutants. One of the challenges of this research was sampling and determining the population of city sparrows. The concentration of these heavy metals (in mg/kg) was measured in feather, muscle, blood, adipose tissue and diet samples of birds collected by systematic sampling (n = 96) from selected parks in the north, south, west and east of the city using inductively coupled plasma optical emission spectroscopy (ICP-OES) under optimal measurement conditions. Based on the results, the unwashed feather samples showed the highest concentration for cadmium, as Cd (449.23)&gt; Ni (4.12)&gt; Pb (3.67), and the washed feather samples indicated that the highest concentration of cadmium in the northern (456.75) and southern (449.23) regions. The concentration of lead in most of the regions had relatively similar values, but it was higher in the northern (5.11) and southern (3.67) regions. The highest concentration of nickel was related to the eastern (29.76) and western (9.76) regions. The comparison of our results reveals the correlation between the concentration of heavy metals studied in different tissues of house sparrows and the distribution of polluting sources in Tehran in terms of traffic load, the establishment of gas stations and industrial pollution transfer routes.To conclude, house sparrow can be used as a suitable biological indicator in determining the distribution of changes in the concentration of some heavy metals.

Source identification of heavy metal contamination in beach sediments of the ancient city of Phaselis in Antalya, Türkiye

The ancient city of Phaselis, which is located along gravel, coarse sandy, and sandy beaches, is a popular area visited by thousands of domestic and foreign tourists every year, and has been selected as the study area. Sediment samples collected from 57 different locations in the ancient city of Phaselis were analyzed using an X-ray fluorescence (XRF) spectrometer, and the major, trace, and rare earth element contents of the samples were revealed. The heavy metals arsenic (As), cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), tin (Sn), stronsium (Sr), and zinc (Zn) were used in the pollution index calculations. Distribution maps revealed that heavy metal concentrations reached higher levels, especially in the eastern part of the study area. Therefore, it is recommended to plant rooted macrophytes that can absorb the heavy metals Cr and Ni and perform phytoremediation of the sediment in the region.

Evaluating Household Hazardous Waste Generation, Composition, and Health Risks in an Urban Municipality

This study aimed to assess the generation rate and composition of household hazardous waste (HHW) in Nakhon Si Thammarat Municipality, Thailand. A questionnaire survey was conducted to collect data on HHW generation and disposal practices from households in the municipality. Soil samples were collected and analyzed for heavy metals (cadmium, chromium, mercury, nickel, and lead) and PCBs contamination. The potential health risks from ingestion exposure associated with heavy metals and polychlorinated biphenyls (PCBs) contamination in the soil were evaluated. The result revealed that in 2023, the HHW generation rate was 11.95 kg/household/year, with the highest percentages occurring of electronic waste (17.40%), fluorescent lamps (16.98%), spray cans (12.38%), cleaning products (11.30%), and engine oil and lubricant oil products (9.87%). The majority of residents (92.90%) disposed of hazardous waste and general waste together in public waste containers. However, the health risk assessment indicated that the levels of heavy metals and PCBs in the soil were within the safe acceptable range for residents, with a total lifetime cancer risk from ingestion exposure of less than 1E-06 for both adults and children. The findings highlight the need for improved waste separation practices and the implementation of effective hazardous waste management strategies to minimize potential health risks and environmental impacts. This study serves as a basis for developing targeted interventions and policies to enhance household hazardous waste management in the municipalities and similar urban areas in Thailand. Doi: 10.28991/HEF-2024-05-03-011 Full Text: PDF

Fitoremediasi Air Tercemar Nikel (Ni) dan Merkuri (Hg) Menggunakan Tanaman Azolla filiculoides Lam.

Water pollution from settlements, agriculture, and industry is a significant issue, as it introduces pollutants like heavy metals into water bodies, harming both humans and aquatic ecosystems. Phytoremediation is a cost-effective, eco-friendly technology for reducing heavy metals in water bodies. This study aimed to assess Azolla filiculoides plants' ability to absorb heavy metals nickel and mercury. The plants were grown in a hydroponic solution contaminated with 0.25 ppm of nickel and 0.5 ppm of mercury. The growth of the plants was measured based on their wet and dry weight, and the nickel and mercury content in the plant tissue was analyzed using Atomic Absorption Spectrophotometry (AAS). The study found that the growth of A. filiculoides plants was unaffected by the concentration of either nickel or mercury. The amount of nickel absorbed by the plants was 0 µg/g plant dry weight, while for mercury, it was 1654.82 µg/g. Based on the results, A. filiculoides plant is more promising for use as a phytoremediation agent for water bodies contaminated with mercury heavy metals rather than nickel heavy metals.