Environmental Nanotechnology, Monitoring and Management最新文献

Heavy metals are the main inorganic contaminants, and their presence in aquatic bodies causes many health and environmental issues. Different man-made activities, such as agriculture, mining, industrialization, urbanisation, thermal power plants, and others, release heavy metals into the water system. These contaminants cause major health issues for humans and other organisms. Adsorption-based heavy metal removal from wastewater is a feasible, adequate, and suitable method for treating a large amount of wastewater. Naturally occurring cellulose is a potential candidate for various applications as a result of its excellent physico-chemical and mechanical features. Several experimental investigations have been conducted in the context of the use of materials based on cellulose for the adsorption-based removal of heavy metals from wastewater. These investigations attempt to determine the extent to which cellulose-based materials may adsorb heavy metals from wastewater or water. The use of nanocellulose-based materials in the adsorptive removal of heavy metals from aqueous media provides some advancements like enhanced surface area, biocompatibility, and superior mechanical features. The present article covers an adequate literature review for the potential of cellulose-based materials in the adsorptive removal of heavy metals.

This study was designed to determine the impacts of different ZnO-NPs concentrations (100–1000 mg kg⁻¹ soil) on soil carbon (C) mineralization of a calcareous soil amended with alfalfa hay (AH) and wheat straw (WS). In addition, C mineralization kinetics in the residue-amended soils were described using different kinetic models and the impacts of ZnO-NPs on the kinetic parameters were investigated. The microbial biomass C (MBC) and basal respiration (BR) were also compared in the treated and control soil samples. The findings revealed a significant reduction in total cumulative mineralized C (C_min) in soil amended with AH at ZnO-NPs concentrations of 100 and 200 mg⁻¹ kg soil. Similarly, in soil samples amended with WS, the C_min value demonstrated a significant decrease across all ZnO-NPs concentrations, except for the lowest concentration of 100 mg⁻¹ kg soil. The results of kinetic analysis using the double first-order model showed that the introduction of ZnO-NPs led to an increase of up to 147 % in the amount of C mineralization during the initial fast phase, while it also resulted in a reduction of up to 27.3 % in C mineralization during the subsequent slow phase. Moreover, the presence of ZnO-NPs in the soil resulted in a noteworthy decrease of 4.44 % to 54.5 % in MBC and 5.12 % to 35.7 % in BR values when compared to the uncontaminated soil, suggesting that the size and activity of the soil microbial community were suppressed, with the extent of suppression varying depending on the type of plant residues and concentrations of ZnO-NPs applied. These findings strongly suggest that the soil microbial community was subjected to heightened toxicity stress caused by ZnO-NPs, particularly at higher concentrations. In conclusion, ZnO-NPs can drastically influence the microbial abundance, maintenance energy demand, and C mineralization process in plant residue-amended calcareous soils.

Pollution in rural waterbodies, sediments, and aquatic species due to long-range transportation and mobilization of heavy and toxic metals contaminants is a growing concern in many developing countries nowadays. Environmental components in rural areas are usually considered as safe and information on metals toxicities in rural natural resources are very limited. Herein, accumulation, mobilization, and distribution of eight different elements (Fe, Ni, Mn, Pb, Cr, Cu, Cd, As) in water bodies and sediments in rural areas of Bangladesh have been investigated successfully. Different metals contents found in water and sediment were compared with standard threshold levels reported by WHO, USEPA, China, and the results revealed the occurrence of pollution in respective environmental resources with the excessive presence of some heavy metals. Pollution characteristics analyses with trace metal pollution index (TPI), heavy metal evaluation index (HEI), contamination index (Cd), and comprehensive pollution index (CPI) indicated that water bodies in rural areas are contaminated with Pb, Mn, Fe, and different metals contents were varied in the order of Fe > Mn > Cu > Pb > Cr > As > Cd > Ni (mg/L). Contamination analyses in sediments with potential ecological risk index (PERI), pollution load index (PLI), metal enrichment (EF), and geo-accumulation index (I_geo) assessments revealed the occurrence of pollution in sediments with Ni, Cr, Cu, and the translocations of different heavy metals in rural sediments were varied in the order Fe > Mn > Cr > Ni > Cu > Cr > Cu > Pb > As > Cd (mg/Kg). PLI data of metals showed higher than one and the magnitudes of I_geo were greater than zero which indicated inordinate accumulation of Ni, Cr, and Cu in sediments. The present research findings offer significant information on how the pollutants from point sources impact the environmental ecosystems in rural areas of Bangladesh due to the long-range pollution with flood and other natural disasters that occur frequently in the region. These results may be useful for making necessary environmental policies in developing countries regarding long-range pollution.

The growing concern over environmental contamination by pharmaceutical compounds has drawn the attention of the scientific community and regulatory bodies worldwide. It is estimated that a wide variety of drugs, including analgesics, antibiotics, hormones, and antidepressants, are widely detected in bodies of water, soil, and even in drinking water supply systems. This contamination represents not only a direct threat to human health and the environment but also challenges conventional water and wastewater treatment systems, which are often ineffective in completely removing these compounds. In this context, advanced oxidation processes (AOPs) emerge as a promising approach for degrading persistent organic contaminants such as pharmaceutical compounds. AOPs are highly effective techniques that involve the generation of reactive oxygen species, such as hydroxyl radicals, capable of oxidizing a wide range of organic pollutants, transforming them into less toxic and more easily treatable products. The importance of using red mud (RM) as a catalyst in AOPs for the treatment of pharmaceutical compounds is underscored by its abundance as a by-product of the aluminum industry and its unique ability to catalyze oxidation reactions. RM is the residue resulting from the Bayer process for refining bauxite to obtain aluminum. Its porous structure and chemical composition rich in metallic oxides confer catalytic properties that can be exploited in the degradation of organic contaminants. In this review, we explore the application of RM as a catalyst in AOPs for the treatment of pharmaceutical compounds. We investigate the mechanisms involved, the methods of preparation and modification of RM for optimizing its catalytic efficiency, as well as review case studies and significant results in the scientific literature. By addressing these aspects, we aim to provide important insights for future research and developments in this area of environmental science and process engineering.

Cadmium in surface waters and the environment beyond the maximum allowed quantities without pre-treatment is hazardous. Bamboo stem biomass adsorption capability for Cd²⁺ remediation from heavy metal-polluted wastewater will be examined to prevent recurrence. The experiment controlled biosorbent dosage, contact length, pH, temperature, and beginning Cadmium concentration for the optimum remediation. Cd²⁺ was best removed at pH 5 with contact time was 90 min at 298 K. Adsorption observed was 4.17 mg/g at 298 K with 4.13 mg/g Cd²⁺ sorbed in 90 min. Metal ion concentration reached upto 80.98 % with q_e 2.01 mg/g while the desorption 91.3 % at 0.05 M of HCl. The kinetic study showed that it follows Lagergren psuedo-second order reaction, Langmuir, and Freundlich models. The bamboo stem biomass performed better at all cadmium concentrations, with heavy metal removal increasing with concentration. According to the results, bamboo stem biomass is effective in heavy metal removal from wastewater. SEM shows biochar has longitudinal pores and a rough surface. Biochar has significant KCl concentration due to its sharp, strong XRD peaks. These findings suggest that bamboo stem biomass is effective in removing heavy metals from wastewater.

Polycyclic aromatic hydrocarbons (PAHs) have been introduced as major pollutants released by the oil, gas, and petrochemical industries. Against this background, the present study examined the coastal air, seawater, and sediments in the Pars Special Economic Energy Zone (PSEEZ), Iran, in terms of pollution caused by such compounds. Considering the industrial facilities and residential areas in this region, the total suspended particulate (TSP), seawater, and sediments were sampled (n = 10) and then analyzed over the course of two seasons via gas chromatography-mass spectrometry (GC–MS). The total concentrations in the TSP, seawater, and sediments were found to be in the range of 346-739ng_PAH/g_TSP, ND-84.87 µg/L, and ND–306.7 ngg⁻¹(dw), respectively. The positive correlation coefficients between sediment organic matter (OM) and concentrations did not show a significant relationship. Crude oil and its derivatives and biomass-coal combustion were identified as the main sources of pollution. Carcinogenic PAHs (CPAHs) were further detected at much higher concentrations near industrial facilities. Sediment quality guidelines (SQGs) and risk quotients (RQs) showed that coastal seawater and sediments posed acceptable and moderate ecological risks. According to the fugacity diagrams, the seabed and seawater served as secondary sources of pollution. The total concentration and values obtained in earlier investigations were also comparable. Nonetheless, most maximum points could provide a point-form of the pollutant concentration. Therefore, preventive measures are required to ensure the protection of the environment.

The emergence of new contaminants like engineered nanoparticles (NPs), pharmaceuticals (PhACs), etc., causes a detrimental effect on the ecosystem and the study needs to be done to understand its behavior in the natural environment. In the present study aggregation and transport behavior of zinc oxide nanoparticles (nZnO) was evaluated in the presence of one of the PhACs, carbamazepine (CBZ). At first, a series of batch experiments were performed with 50 mg/L of nZnO and 1 mg/L of CBZ at different pH (6 and 8) and electrolyte concentration (EC: 1 mmol/L and 20 mmol/L), to study the change in the hydrodynamic diameter of nZnO. The result indicates that the extent of aggregation of nZnO increases with an increase in EC from 1 mmol/L to 20 mmol/L of NaCl or CaCl₂. However, in the presence of CBZ, shows greater colloidal stability at lower EC, and its effect was found to be nominal at higher EC. The transport behavior of nZnO and CBZ was assessed by column experiment, it was found that more than 97 % of nZnO and 99 % of CBZ are retained in the porous media during the injection for different test conditions. Moreover, during transport experiments of longer duration, less than 10 % of nZnO and about 72 µg/L of CBZ were released in the effluent. Therefore, the risk of the release of nZnO is reduced in the presence of CBZ.

Globally utilization, toxicity, and bioaccumulation of Tetracycline (TC) and Metronidazole (MNZ) have received great attention from researchers during the past decades. In this study, the fabrication of Ag-doped CeO₂@SnO₂ was achieved by a green method using A. indica leaf extract for the efficient removal of selected antibiotic drugs (TC and MNZ) from water. The fabricated nanomaterial’s were characterized by PXRD, FT-IR, FE-SEM, BET, TEM, and XPS techniques. The XRD and BET outcomes showed that synthesized Ag-doped CeO₂@SnO₂ have characteristic crystalline structures with high surface area (102 m²g⁻¹) respectively. FT-IR analysis confirmed the doping of Ag in the CeO₂@SnO₂ nanocomposite. Particularly, the Ag-CeO₂@SnO₂ photocatalysts showed a greater photocatalytic degradation rate for the selected drugs under Sunlight illumination compared to parent photocatalysts. Ag-CeO₂@SnO₂ caused highest degradation (96 %–94 %) of pollutants was found at 10 mg L⁻¹ of TC and 2 mg L⁻¹ of MNZ concentration, 20 mg of photocatalyst dosage, and pH ∼ 7 under sunlight irradiation (5 h) with. The presence of different reactive species (holes, hydroxyl radicals, and superoxide’s radicals was confirmed by the quenchers (t-BuOH, p-BZQ, Na₂EDTA) revealed their significant role for the removal of the targeted pollutants. Formation of safer metabolites after degradation of TC and MNZ was confirmed by GC–MS analysis. Fabricated Nanocomposite (Ag-CeO₂@SnO₂) demonstrated remarkable stability and sustainability by remaining unaltered up to 8th cycles without significant loss in its activity. Present study advocated fabrication of an efficient and alternative photocatalyst for treatment of industrial waste with a bright future.

Global economy is inching towards the reduction of waste which is a major concern for the industries worldwide. This study revealed the surface modified Cotton and Flax fabrics via Silver Nanoparticles for the degradation of organic pollutant found in industry wastewater. In situ synthesis was used for development of Ag-treated cotton and flax fabrics using ascorbic acid as a reducing agent through dipping into the silver nitrate solution prepared by chemical reduction. Treated fabrics were characterized by a Fourier Transform Scanning Electron Microscope, Energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, Thermogravimetric analysis, and also an Anti-microbial test. The SEM study revealed a good presence of AgNPs with average particle sizes of silver being 53.5 nm and 132.75 nm for silver treated Cotton and Flax fabrics respectively. Analysis of weight loss behavior showed lower thermal consistency for Fx-Alk-Ag fabric rather than Co-Alk-Ag. The bacterial resistance against E.coli recorded by ZOI value for Co-Alk-Ag and Fx-Alk-Ag were 12 mm and 10 mm respectively. The alkali treated fabrics exhibited as adsorbents and also operated as photocatalysts for degradation of organic pollutants from aqueous medium. The Co-Alk-Ag and Fx-Alk-Ag adsorbents explored an outstanding degradation performance of MB with 90.45 % and 99.37 % within 60 min without using any reducing agent. Prominent adsorption phenomena have been noticed in Flax fabrics than in the Cotton fabrics. Linear fittings and R² values gave conclusive evidence on Langmuir model to be better suited for isotherm phenomenon in the treated fabrics than the Freundlich model. The adsorption phenomenon was evaluated using the Intraparticle Diffusion model where quick adsorption and continuous slow diffusion were found responsible for dye removal. According to these research results, Co-Alk-Ag and Fx-Alk-Ag would have a great opportunity in the degradation of textile pollutants as well as the antimicrobial properties of these composites.

Lead-acid battery industries in Bangladesh have proliferated in urban areas, leading to the release of significant amounts of potentially toxic elements (PTEs) and metalloids into the environment. This study aimed to assess the spatial distribution, sources, contamination status, and ecological risks in agricultural soils, vegetables, and fruits near these industries. Soil samples were collected from four sites at varying distances (0 m, 100 m, 250 m, and 500 m) around three lead-acid battery industries (AA, AB, and AC) in Dhaka and Gazipur Districts during June-July 2020. The concentrations of the Pb, As, Cd and Zn in agricultural soils were ranged between 8.40–116.61, 8.99–28.21, 0.03–1.28, and 25.38–68.72 mg/kg, respectively. The concentrations of Pb, As, and Cd were found to be considerably higher than background levels across all industries, with a gradual decrease in PTE concentrations from 0 m to 500 m. The contamination factor indicated high to moderate contamination in agricultural soils by As, Cd, and Pb, and low contamination by Zn. pollution load index, modified contamination degree, and nemerow comprehensive index revealed varying pollution levels in the vicinity of the industries, with AA and AB showing higher pollution compared to AC. The individual risk factors demonstrated significant risks associated with Cd and As exposure, while Pb and Zn posed lower risks. The potential ecological risk index indicated considerable ecological risk for AA (risk index = 192.41), moderate risk for AB (risk index = 111.80), AC (risk index = 65.08), respectively. Correlation and principal component analysis revealed strong positive associations (p < 0.01) among the chemical parameters and potentially toxic elements in soils, and demonstrated the lead-acid battery industry as the primary contamination source in the studied areas. There were strong positive relationships (p < 0.01) existed between As, Cd, and Zn in soils and vegetables; while a strong negative association found between As in soils with As in Fruits. The cluster analysis showed EC, OC, OM, Pb, As and Zn into separate group, implied their same source of origin as anthropogenic source. The metal uptake was in the decreasing order of Cd > Zn > As > Pb and Cd > Zn > Pb > As in vegetable and fruit samples, respectively and transfer factor analysis highlighted Cd and Zn as metals with higher absorption rates in vegetables and fruits. Among the industries, AA and AB were significantly impacted on soil quality, and considerable metal accumulation found on vegetables. The human health risk assessment results indicate a potential noncarcinogenic health hazard for the populations surrounding the industries (AA, AB, and AC). This is evidenced by the calculation of the total target hazard quotient and the hazard index, both of which exceeded the acceptable level (>1). However, the carcinogenic health risks arising from the consumption of potentially toxic element