Water, Air, & Soil Pollution最新文献

This study addresses groundwater quality in Madurai block by examining heavy metal contamination and its potential health risks. Being the second largest city after Chennai, Madurai’s groundwater quality has not been analyzed for heavy metal contamination so far. In 2022, groundwater samples were taken from 60 wells in the pre- and post-monsoon seasons. The heavy metal concentrations of Cu, Cr, Cd, Co, Fe, Mn, Ni and Zn were measured. The results showed that most of the groundwater samples exceeded the (World Health Organisation (2019) World health statistics overview: Monitoring health for the sustainable development goals), (Bureau of Indian Standards (2012) Drinking water specifications) and (USEPA (2018) National primary drinking water regulations (EPA 816-F-09–004)) limits for drinking water. A spatial analysis using kriging interpolation in GIS and a multivariate statistical analysis were performed to decipher the interrelationships of the metals. The results indicate different sources of heavy metals, primarily caused by weathering and evaporation in both seasons. Pollution indices such as HPI, HEI and DOC were used to comprehensively assess the extent of metal pollution in groundwater. The Hazard Quotient and Hazard Index emphasized the significant health risks to infants, children and adults. To improve the quality of groundwater, this region needs to adopt sustainable and environmentally friendly water management strategies, such as rainwater harvesting, wastewater treatment and strict pollution control measures.

This review presents the first comparative analysis of functional chemical additives in various types of single-use plastics (SUPs). These plastics, commonly used in industries like packaging, food service, and healthcare, contain additives such as stabilizers, colorants, flame retardants, and plasticizers to enhance their flexibility, durability, and appearance. However, many of these additives are not chemically bonded to the polymer matrix and can leach out during the plastic's life cycle, posing risks to human health and the environment. The review explores the functional characteristics, mechanisms, and benefits of these additives, and highlights recent advances in bio-based and additive-free alternatives. The study also uses the AGREEMIP tool to assess the greenness of the synthesis processes for various SUP products, ranking them in the order of environmental safety: disposable plastic containers for hedgehogs > disposable plastic dances > disposable glasses and plates > drinking straws and sticks > plastic bags.

Exploring the kinetic adsorption and desorption of Americium (Am(III)) on sediments and natural colloids can effectively predict its solid–liquid distribution behavior in the environment. In this study, we used batch and stirred flow-through experiments to describe the kinetic adsorption and desorption process of Am(III) on Am(III)-sediments (AS) system and Am(III)-sediments-natural colloids (ASN) system under different conditions (such as solution pH, background electrolyte concentration, and solution injection velocity). The retention and desorption behavior of Am(III) was analyzed through adsorption distribution coefficients and breakthrough curves. The kinetic adsorption process was described using reaction and transport control models. The results showed that in the batch adsorption experiment, the presence of natural colloids significantly increased the adsorption distribution coefficient of the ASN system (249.11—2512.74 mL/g) compared to the AS system (233.05—447.29 mL/g). The retention of Am(III) in the stirred flow-through reactor in AS (70.26% - 73.64%) and ASN (74.13% - 76.25%) systems is relatively high under neutral and low flow rate conditions, which is attributed to the strong adsorption ability of dispersed and stable natural colloids and the sufficient adsorption time provided by low velocity. According to the fitted results of the models, it can be seen that physical reactions such as surface precipitation or surface complexation, as well as diffusion of the liquid surrounding the solid-phase adsorbent, dominate the kinetic adsorption process, which is time-dependent or non-equilibrium.

This is the first report on improving activated carbon fabric (ACF) as an adsorbent for the removal of heavy metals. Magnetic-activated carbon fabric (MACF) was synthesized from waste cotton fabric using a sonosynthesis method with iron salt for removing Cu²⁺ and Cd²⁺ ions from aqueous solutions. MACFs were characterized with BET, FT-IR, and VSM methods. Optimal conditions for ions removal were pH = 4 for 50 mg L⁻¹ initial concentration of Cu²⁺ and Cd²⁺ with 1.5 g L⁻¹ MACF at 20 ± 1 °C and 200 rpm for 1 h. The equilibrium data of adsorption thermodynamics, isotherms, and kinetics of Cu²⁺ and Cd²⁺ using MACF was investigated. The highest regression values of 0.9998 and 0.9750 were obtained by the Langmuir model among other models for adsorption isotherm using MAFC for Cu²⁺ and Cd²⁺ respectively. MACF revealed a higher metal removal of 99.2% for Cu²⁺ and 94.9% for Cd²⁺ for both ions compared to 32% for Cu²⁺ and 28% for Cd²⁺ using ACF. The results indicate that MACF shows superior performance/cost-effective in removing heavy metal ions compared to granules and powder-activated carbons, which can be easily prepared in different dimensions and removed from the filter/environment, making it a promising alternative for applications requiring enhanced heavy/toxic metal removal from any solution.

The study presents initial findings regarding the occurrence and ecological risk assessment of organochlorine pesticides (OCP), polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) in the Neretva Delta sediments, including 28 potentially toxic elements (PTEs) considering limited element studies. Parameters such as solvent type, temperature and number of extraction cycles were optimized for the accelerated solvent extraction (ASE) of PAH from brackish sediment samples. Mixture of cyclohexene: toluene (3:7, v/v) and four extraction cycles at 125 °C provide efficient extraction with recoveries ranged from 86 to 115% and relative standard deviation lower than 19%. Based on the proposed sediment and environmental quality screening standards, levels at all sampling sites may be considered as rare (PCB, OCP) or occasional (certain PAH) risk to aquatic life. The sediment-associated levels generally decreased in the order of contaminant groups: PAH > > PCB > OCP. The 28 PTEs decreased in the following order: Ca > Mg > Al > Fe > S > K > Si > Na > P > Ti > Mn > Sr > Zn > Sb > Cr > Ba > B > Ga > V > Cu > Pb > Li > Ni > As > Mo > Sn > Cd > Be. Specifically, elevated levels of As, Cd, and Mo suggest potential environmental risks, warranting further detailed monitoring and assessment.

In the present study, surface soil samples from Nagpur city, India, were studied for the fractionation of potentially toxic metals using a modified European Community Bureau of Reference sequential extraction procedure (SEP). The results indicated that the metals Cd, Pb, Co, and Zn showed substantial associations with the mobile fraction (F1: soluble + F2: reducible). The mobile fraction of the metals followed the order Cd (73%) > Pb (47%) > Co (29%) > Zn (25%). The metals Cr, Cu, and Ni were predominantly associated with the residual fraction (F4), suggesting their geological origin, whereas Zn and Co were distributed across all fractions, with higher concentrations in the oxidizable and residual fractions (F3). The ecological risk assessment revealed that Cd, Cu, Ni, and Pb posed greater risks in industrial and residential areas, indicating that industrial and anthropogenic activities were the primary sources of heavy metals. The chronic toxic risk to children, i.e., the hazard quotient (HQ) of heavy metals (∑₆HM), exceeded the threshold limit for ingestion and dermal routes in residential and commercial areas, respectively, whereas for adults, the HQ was closer to the threshold limit of 1 (5.13 × 10^–1). The cumulative carcinogenic risk for children and adults was unacceptable (> 1 × 10^–4) and attributed to the relatively high levels of Cd, Cr, and Pb in soils. These findings underscore the need for risk reduction measures to safeguard human health and reduce the ecological impact of heavy metal pollution.

An innovative approach to the treatment of textile wastewater by utilizing fine fractions of construction and demolition waste (CDW) as a cost-effective adsorbent is presented in this work. Through batch experiments, the impact of key parameters on the adsorption process was explored, identifying optimal conditions: natural pH, adsorbent dosage (S/L) of 20 g L⁻¹, and temperature of 20 °C. The characterization of CDW was performed using ICP, BET, FTIR, SEM–EDX, XPS, and XRD. The kinetics of adsorption were effectively described by the Elovich model, while equilibrium adsorption data showed good agreement with the Freundlich model. The maximum monolayer adsorption capacity for acid blue AB113 dye on CDW obtained from Langmuir isotherm was 89.52 mg g^–1. Thermodynamic analysis indicated an exothermic and feasible nature of the adsorption process. The results of this study highlight the potential use of fine CDW as a promising adsorbent to remove acid blue113 dye from textile wastewater.

Graphical Abstract

Air pollution has significantly increased during the Anthropocene, adversely affecting ecosystems and human health. The National Emission Ceilings Directive (NECD, 2016/2284/EU) set targets for reducing emissions and required Member States to establish a national monitoring network to assess ecosystem changes due to air pollution. For freshwaters, the NECD monitoring focused on assessing effects of sulphur and nitrogen deposition and acidification status using chemical parameters and sensitive biological indicators. This paper evaluates the present NECD monitoring scheme and its applicability in Italy, from site selection to initial data collection. High mountain lakes were selected as study sites, because they are free from direct human impacts and sensitive to air pollutant deposition. A two-year survey of chemical and biological components (diatoms and macroinvertebrates) was conducted in eight lakes with the aim to (1) assess the suitability of chemical parameters and biological indices for evaluating air pollutant impacts on sensitive water bodies in Italy, focusing on acidification and nitrogen enrichment, and (2) discuss the current approach's achievements and limitations. Results highlighted the need to develop specific indices for detecting atmospheric pollution impacts on freshwater ecosystems. Beside acidification, other drivers, including nutrients, proved to be important in shaping mountain lakes biological assemblages and affecting their response to pollutant deposition. Our study contributed to a critical assessment of the present freshwater monitoring under the NECD from the Italian perspective, providing indications on future improvement and development of the monitoring scheme itself.

Exorbitant dye contamination in water augments health quandaries in living beings. Besides, expired medicines induce secondary hazards owing to mismanaged, rampant disposal in environments. To quench the dual problem, the waste-to-best protocol was exercised maneuvering the conversion of an expired medicine ‘Oflofrenz-OZ’ to activated carbon (OAC) followed by extraordinary ultrafast scavenging of recalcitrant bromothymol blue (BTB), and crocein orange (CO) from water. The material is well characterized using powder XRD, FESEM-EDX, pH_ZPC, and BET surface area. FESEM exhibits a highly porous morphology, evenly decorated, thereby offering a favorable dye-hosting platform. Outstanding adsorption capacities for BTB and CO (362.318 and 1008.089 mg/g) are powered by ultrafast kinetics, obeying the Langmuir monolayer model (R² = 0.999). Mild alkali-assisted regeneration revives the material by up to 50%, enabling three-cycle reuse. OAC performs well with simulated wastewater from tube-well, tap, and reverse osmosis systems, which synergistically advocates field applicability. The long-hankered disposal problem of dye-loaded spent material has been addressed by converting it to a second-generation carbon-based adsorbent with an 80% yield. Compared with analogous materials, the present material is a clear winner, thanks to its extraordinary adsorption efficacy, economic viability, and zero footprints.

Presence of azo dyes in industrial wastewater is an environmental and health hazard. The available removal methods generally are high cost and difficult to operate. This study optimizes Reactive Black 5 (RB5) adsorption process using polyurethane sponge containing sodium alginate and TiO₂ NPs (PSAT). The results show that Langmuir isotherm (R²-0.999) was best fitted isotherm and Elovich (R²-0.99) was the best fit kinetic model. The Central Composite Design (CCD) assessment guided by Response Surface Methodology (RSM) modelling was used to optimize variables (pH, initial dye concentration, and contact time) for dye removal. The ANOVA analysis of the results from 17 experiments suggested by RSM shows that all three parameters significantly affect the dye adsorption capacity. Under optimal set of condition (pH 7, initial dye concentration of 102.5 mg/L, and a contact time of 255 min) a maximum removal of 59.61 ± 2.26% was predicted by RSM, which in our experiment was found to 59.32 ± 2.36%. The R² value (0.99) of quadratic correlation established to calculate the optimum conditions were in good agreement with the adjusted R² (0.98). The adsorbent was thoroughly studied using TEM, SEM with EDS, and FTIR. It is concluded that PSAT can be used as a low-cost, and easy to use adsorbent for the removal of azo dyes from small scale industry wastewater.