Heavy metals are toxic especially when they are introduced into the environment due to anthropogenic activities such as metallurgy, mining, and tanning. Removing these pollutants has become a worldwide concern since they cannot be degraded into nontoxic forms causing extended effects in the ecosystems. The use of an Aspergillus australensis was evaluated in order to remove Cu²⁺ from simulated wastewater. The fungus was isolated from river sludges contaminated with heavy metals and was first evaluated for the determination of Cu²⁺ tolerance levels. Microscopic fluorescence analysis was carried out to determine the effect of Cu²⁺ presence on the viability, cellular components, polyhydroxyalkanoates production, and oxidative stress of the fungus, as a response to the stress caused by exposure to metal. In order to achieve copper removal, the A. australensis biomass was produced using batch cultures, and the mycelium was immobilized on a textile media in order to compare the copper-removal efficiency of live or dead biomass. The optimal values of pH and temperature for biomass production were established by using a surface response analysis. Live immobilized biomass was capable of removing Cu²⁺ from 1.54 ± 0.19 to 2.66 ± 0.26 mg of copper/ g of dry biomass, while values of 1.93 ± 0.03 to 2.36 ± 0.29 mg of copper/g of dry biomass were observed when dead biomass was used. As was expected, copper removal using biomass varied depending on the pH and temperature used.

For several decades air pollution has been recognized to hit drastically the skin of human body. Air pollutants predominantly accountable for aging, oxidative damage, and inflammatory allergic reactions led to psoriasis, dermatitis, acne, and skin cancer owing to the impaired functions of DNA, proteins, and lipid biomolecules. Elevated air pollution and its detrimental effects along with variations in physiological parameters of the skin are verily the scaffold for anti-pollution assertions and could be recognized as markers. The present article encompasses the salient features of air pollution and UV radiations besides dreadful effects on human skin physiological parameters and some anti-pollution approaches.

Azo dyes are extensively used in different industries areas, such as Allura Red (R-40). Previous studies have proven its carcinogenic and mutagenic properties. For the removal of this type of emerging pollutant from effluents, tertiary treatment techniques such as activated charcoal are used. Alternatively, the use of bacteria is preferred because of its quick discoloration processes. The aim of the present investigation is to compare the efficiency removal of R-40 from aqueous media by a physicochemical process and a biological one. The sorption kinetics of 10 ppm of R-40 was carried out with the use of activated charcoal based on walnut shells in water. Moreover, Pseudomonas aeruginosa and Bacillus subtilis stains were used separately to decolorize nutrient broth media supplemented with 50 ppm of R-40. The activated carbon was capable to remove 99.87% of R-40 at 264 h, while the bacterial strains decolorized 92.13% (P. aeruginosa) and 88.21% (B. subtilis), respectively, under microaerophilic conditions after 168 h. Therefore, both process strategies, physicochemical and biological rapprochements, were able to remove the dye from aqueous media. R-40 was not cytotoxic to used strains, besides gram-positive either negative bacteria could be applied to turn over this azo dye in short term. Combination of both approaches may be implemented in tandem architecture.

Effects of Polygonum equisetiforme extracts against dichlorvos were investigated in the commercial clam Ruditapes decussatus. The toxicity of this pesticide was firstly tested in R. decussatus gill and digestive gland tissues using five doses varying from 0.05 to 1 mg/l during 2, 4, and 7 days. Results showed that 0.05 mg/l of DDVP induced oxidative stress and neurotoxicity in R. decussatus after 2 days of exposure. Investigations of the effects of P. equisetiforme extracts in R. decussatus exposed to 0.25 mg/l of DDVP were made in clams receiving three concentrations (0.009, 0.045, and 0.09 g/l) during 4 and 7 days. Antioxidant enzymes SOD and CAT as well as H₂O₂ content and AChE were quantified by colorimetric method. Four days of exposure to DDVP increased SOD and CAT activities and enhances H₂O₂ content. AChE levels decreased considerably following DDVP exposure, although a restoration in the enzyme activity was observed with P. equisetiforme extract (E3 = 0.09 g/l). Overall, P. equisetiforme extract at concentration (E1 = 0.009 g/l) prevents oxidative stress caused by DDVP, while 0.09 g/l of P. equisetiforme extract induced an effect similar to that obtained with DDVP alone. Nevertheless, this concentration was found effective for the restoration of the AChE activity.

Widespread application of titanium dioxide nanoparticles (nTiO₂) and ubiquitous cadmium (Cd) pollution may increase their chance of co-existence in the natural environment. Toxicological information on co-exposure of nTiO₂ and Cd in mammalian models is largely lacking. Hence, we studied the combined effects of nTiO₂ and Cd in human liver (HepG2) and breast cancer (MCF-7) cells. We observed that nTiO₂ did not produce toxicity to HepG2 and MCF-7 cells. However, moderate concentration of Cd exposure caused cytotoxicity to both cells. Interestingly, non-cytotoxic concentration of nTiO₂ effectively enhanced the oxidative stress response of Cd indicated by pro-oxidants generation (reactive oxygen species, hydrogen peroxide, and lipid peroxidation) and antioxidants depletion (glutathione level and glutathione reductase, superoxide dismutase, and catalase enzymes). Moreover, nTiO₂ potentiated the Cd-induced apoptosis in both cells suggested by altered expression of p53, bax, and bcl-2 genes along with low mitochondrial membrane potential. Cellular uptake results demonstrated that nTiO₂ facilitates the internalization of Cd into the cells. Overall, this study demonstrated that non-cytotoxic concentration of nTiO₂ enhanced the toxicological potential of Cd in human cells. Therefore, more attention should be paid on the combine effects of nTiO₂ and Cd on human health.

Chromium (Cr), one of the most abundant and hazardous heavy metals, is generally observed to be widely distributed in environment, primarily due to the inter-mixing of the untreated domestic and industrial wastewaters. There has been an increased interest to replace conventional centralized treatment technologies with the low energy, low cost, and zero sludge producing decentralized constructed wetland technology. Therefore, a long-term investigation on the comparative metal removal efficiency of the experimental vertical sub-surface flow (VSSF) constructed wetland systems, irrigated with Cr-spiked ground waters, under both mono and mixed-culture conditions planted with five different macrophytes viz. Typha (T), Phragmites (P), Acorus (V), Arundo (A), and Vetiver (K), in as mono- and {viz. (TP), (PA), (KV), (AT), and (VT)} as co-cropped combinations along with unplanted (U) systems as controls was conducted at the ICAR-Indian Agricultural Research Institute, New Delhi, India. Long-term investigations revealed significant differences between metal removal efficiencies of the planted (61.6% to 78.5%) and the unplanted systems (32.8% to 47.9%). However, these long-term average metal removal efficiencies were found to be insignificantly different for the mono (78.5%) and the co-cropped systems (77.6%). On further compartmentalization of the experimental wetland system’s Cr-removal efficiencies amongst the major components viz. plant, microbe, and substrate, it was observed that vegetation contributed the maximum (i.e., 33–48%) while the microbes and the substrate contributed only 4–20% and 8–28%, respectively. It was further observed that due to reduced microbial diversity under unplanted conditions, the planted systems were associated with 2–7% higher microbial and equivalently lower substrate removal efficiencies. Thus, microbial activity-mediated metal mobilization and plant uptake were observed to be the principal processes governing Cr removal in the test VSSF constructed wetland systems exposed to varying Cr concentrations. Amongst all test macrophytes and their combinations, Arundo (81.9%) and Acorus (84.5%) based monocropped systems and Arundo+Typha (89.3%) based co-cropped systems emerged to be the most superior Cr-removing systems. Graphical abstarct

Continued long-term monitoring of vegetation activity in national key ecological function zones (NKEFZs) has implications for national ecological security and sustainability in China. We used Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) dataset to map and analyze the spatiotemporal patterns of change in vegetation growth and their linkage with climate change and human activities in NKEFZs during 1982–2013. Statistically significant increases of growing season, spring, and autumn NDVI were observed during all or most periods while 25 NKEFZs are taken as a whole. Non-significant decreases of NDVI were found in 7 NKEFZs during a few periods, and obvious increases were observed during fifteen periods in all other NKEFZs. Vegetation growth in NKEFZs was mainly regulated by a thermal factor, and the dominant climatic drivers varied across different regions and seasons. The influence of temperature was stronger on vegetation activity in spring and autumn for those NKEFZs located in high latitudes and high elevations, while precipitation was the main climatic control factor for NKEFZs in the arid and semi-arid regions. The effects of human activity on the NDVI of NKEFZs were not ignored; a significant decrease of NDVI in the Sanjiang Plain may be related to the rapid change in land use from wetland into farmland.

In recent years, the volume of wastewater produced worldwide has led to an increase in the study and use of different membranes and their properties. The progress of membrane technology in hand with nanotechnology has brought to the establishment of advanced membrane materials that are effective in the field of wastewater treatment and water reclamation. This study focuses on the effectiveness of exfoliated hydrotalcite (EHT) nanosheets in the membrane structure which has been evaluated by water flux and heavy metal rejection studies from aqueous solutions. Moreover, the shedding of HT in an organic polar solvent provides a new type of 2-D nanosheet with higher positive charge density. Hydrophilicity, porosity, surface and cross-section morphology, functional groups, and mechanical strength are determined to characterize the prepared membranes. The effect of adding a pore-forming agent to the dope solution is also investigated. Increased hydrophilicity of the modified membranes is confirmed by water contact angle measurement. Furthermore, EHT is found to be an efficient inorganic additive to get better membrane performance and can be employed as a promising candidate for the removal of Pb²⁺. The rejection % enhanced substantially (50.2% as compared with 29.5% for PES membrane) with increased loading of EHT up to 0.5 g.

In the French West Indies, the chlordecone (organochloride pesticide) pollution is now diffuse becoming new contamination source for crops and environment (water, trophic chain). Decontamination by bioremediation and chemical degradation are still under development but the physical limitations of these approaches are generally not taken into account. These physical limitations are related to the poor physical accessibility to the pesticides in soils because of the peculiar structural properties of the contaminated clays (pore volume, transport properties, permeability, and diffusion). Some volcanic soils (andosols), which represent the half of the contaminated soils in Martinique, contain nanoclay (allophane) with a unique structure and porous properties. Andosols are characterized by pore size distribution in the mesoporous range, a high specific surface area, a large pore volume, and a fractal structure. Our hypothesis is that the clay microstructure characteristics are crucial physico-chemical factors strongly limiting the remediation of the pesticide. Our results show that allophane microstructure (small pore size, hierarchical microstructure, and tortuosity) favors accumulation of chlordecone, in andosols. Moreover, the clay microporosity limits the accessibility of microorganisms and chemical species able to decontaminate because of poor transport properties (permeability and diffusion). We model the transport properties by two approaches: (1) we use a numerical model to simulate the structure of allophane aggregates. The algorithm is based on a cluster–cluster aggregation model. From the simulated data, we derived the pore volume, specific surface area, tortuosity, permeability, and diffusion. We show that transport properties strongly decrease because of the presence of allophane. (2) The fractal approach. We characterize the fractal features (size of the fractal aggregate, fractal dimension, tortuosity inside allophane aggregates) and we calculate that transport properties decrease of several order ranges inside the clay aggregates. These poor transport properties are important parameters to explain the poor accessibility to pollutants in volcanic soils and should be taken into account by future decontamination process. We conclude that for andosols, this inaccessibility could render inefficient some of the methods proposed in the literature.

This paper proposes a quantitative method to optimize the existing river monitoring network based on a modified approaching degree model, T test, and Euclidean distance. In this study, the Liaohe River located in Liaoning province, China, was taken as a research object. Samples were collected from 8 sampling sites throughout the monitoring network, and water quality parameters were analyzed every 2 months from January 2009 to December 2010. The results show that the average concentrations of the ammonia nitrogen (NH₄⁺-N) and chemical oxygen demand (COD) were beyond grade III of the Environmental Quality Standards for Surface Water of China (GB3838-2002), and they were the main water quality parameters. After optimization, the number of monitoring sections along the Liaohe River was reduced to five from the original eight, thus saving 37.5% of the monitoring cost; meanwhile, there is no significant difference between the un-optimized and optimized monitoring networks, and the optimized monitoring network remains to be able to perform as good as the original one. In addition, the total data attainment rate was improved greatly, and the duplicate setting degree of monitoring points decreased significantly compared with other optimal methods. The optimized monitoring network proves to be more efficient, reasonable, and economically feasible, so this quantitative method can help optimize the changing orderly river monitoring networks.