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The large amounts of nitrogen-containing mineral fertilisers in industrial agriculture are leading to water pollution with effects such as eutrophication and death of aquatic life. There is therefore a need for techniques to keep N in the soil to prevent leaching in waters. Here, we tested the effect of the addition of vermiculite, a phyllosilicate mineral, to the soil, on fertiliser NH4 +-N retention in laboratory experiments during 14–45 days. The added amount of vermiculite was twice the amount of the nitrogen fertilizer added. Our results show that addition of vermiculite increases NH4 +-N retention by over 30%, compared to a control. Adding vermiculite is thus a promising technique to control the eutrophication of water systems as well as reducing agriculture cost.

Genomic technologies have been used to improve cultivated crop species. For example, Bt genes such as Cry1Ac, Cry2Ab, Cry1F and Cry3Bb1 are derived from Bacillus thuringiensis, a soil bacterium. Such genes provide protection against lepidopteran insect pests. Bt genes have been introduced in corn, cotton, soybean, rice, potato and canola. Genetically modified (GM)-cotton, containing the Cry1Ac gene, was released for cultivation in the mid-1990s in the USA and later in 28 countries including China and India. Potential harmful effects of the Bt-crops on non-targets were assessed before release into the environment. Most commonly, cultivation of the Bt-crops was found safe. Safety was tested using various experiments including: the insertional impact of transgene and its regulatory elements on plant phenotype and agronomic performance; effect on non-target organisms; and nutritional impacts on multiple experimental models, albeit the studies were conducted for limited durations. However, skeptics always claim for conducting extensive clinical as well as field trials and also cast doubt on methods and procedures of calculating the ecological risks. This debate got further momentum especially after the publication of reports on substantial reduction in monarch butterfly caterpillars when exposed to Bt-maize pollen—though later nullified—and detection of traces of transgene in various tissues of experimental animals. It is generally accepted that procedures, methods and protocols for evaluating the potential risks of GM-crops and foods should be standardized for building confidence of all stakeholders. Efforts should be exerted in deploying genes of interest, marker genes and regulatory sequences invoking no or little issues of potential risks to the ecosystem.

Investigations presented in this paper were aimed at defining the alterations of n-alkane composition in cases of oil-polluted alluvial sediments. Therefore, oil-polluted groundwater samples, taken in five different time intervals during a period of 28 months, were investigated. Samples of alluvial sediments were taken from two boreholes within an oil refinery at Pancevo, Yugoslavia. In both boreholes significant alterations with characteristic degradation of "oil" n-alkanes with no odd- or even-member predominance were observed, as well as subsequent synthesis of new ones with pronounced even-member predominance, and with maxima at C16 and C18. Since no additional contamination of boreholes was observed by analyses of steranes and triterpanes, the observed changes can only be attributed to microbial activity. It is assumed that for the degradation of oil n-alkanes, as well as for the synthesis of "new" n-alkanes, algae such as dinoflagellates are responsible. This assumption was confirmed by identification of n-alcohols with even-member predominance (C14–C20), by identification of cholesterol, as well as of n-fatty acids with even-member predominance (C14–C18) in the extract with n-alkane even-member predominance.

Mercury emission from industrial activities has become a major environmental health concern, because mercury is one of the most toxic metals encountered in the environment. Elemental mercury is the dominant Hg species in gas streams. Adsorption is regarded as a practical technique for Hg0 removal, for which developing efficient and economic adsorbents are needed. Chalcogenides have recently gained increasing research interest owing to their high binding affinity for Hg0. Chalcogen-based adsorbents include S-modified adsorbents, H2S- and SO2-activated adsorbents, polysulfide chalcogels, mineral sulfides and metal selenides. This article reviews chalcogen-based adsorbents for Hg0 capture from gas streams, with focus on removal performances, mechanisms, advantages and disadvantages. Results show that S modification, and H2S and SO2 activation generate a great variety of active sulfur species on the adsorbent surface, resulting in enhanced Hg0 removal activity. Sulfur species include elemental sulfur, sulfide, thiophene and sulfate. Nonetheless, removal efficiency decreases to some extent due to the presence of acidic flue gas components and steam. On the other hand, mineral sulfides and metal selenides exhibit outstanding Hg0 removal performances with fast adsorption rate, high mercury capacity and excellent resistance to SO2 and H2O. Yet most mineral sulfides and metal selenides perform well below 100 °C, which might limit industrial applications.

Fate and risk of nanomaterials in the environment have attracted wide attention over the years. Copper hydroxide (Cu(OH)2) nanorods have been used as antibacterial nanomaterials in agricultural products, leading to their release into the environment. Yet, knowledge about the transformation of Cu(OH)2 nanorods is currently scarce, representing a potential for the environment. Here we investigated the sulfidation process of Cu(OH)2 nanorods by dissolved sulfide (Na2S) in aqueous solutions with varied molar ratios of Cu(OH)2 nanorods versus Na2S. The solid products were characterized with focus on the roles of dissolved oxygen (DO) and dissolved sulfide on CuS formation. The impact of sulfidation on the toxicity of Cu(OH)2 nanorods for Escherichia coli was also investigated. Copper oxide (CuO) nanorods with comparable morphology to Cu(OH)2 nanorods were identified as the intermediate of Cu(OH)2 nanorods sulfidation. We proposed that in situ formation of self-assembly CuS nanorods was achieved through an anion-exchange reaction between O2− of CuO and S2− of Na2S. We found that sulfidation enhanced the toxicity of Cu(OH)2 nanorods to E. coli: the inhibition of E. coli growth increased from 1.2 to 22.6% with increasing sulfidation due to an increase of dissolved Cu concentration.

Industrial activities play a relevant role in environmental pollution since their wastes contain high concentrations of toxic elements that can add significant contamination to natural water and other water sources if no decontamination is previously applied. As toxic metals and metalloids are not biodegradable and tend to accumulate in living organisms, it is necessary to treat the contaminated industrial wastewaters prior to their discharge into the water bodies. There are different remediation techniques that have been developed to solve elemental pollution, but biosorption has arisen as a promising cleanup and low-cost biotechnology. Biosorption is governed by a variety of mechanisms including chemical binding, ion exchange, physisorption, precipitation, and oxide reduction. This review presents applications of biosorbents for metals and metalloids removal. Biomaterials including bacteria, fungi, algae, plant derivatives, agricultural wastes, and chitin–chitosan-based materials are considered. Also, bio-nano-hybrid materials, which have superlative sorption properties due to their high surface area coming from the nanomaterials structures and multifunctional capacity incorporated from the several types of chemical groups of biomaterials, are discussed. High metal removal percentages as high as 70–100% can be found in most works reported in the literature, which demonstrates the excellent performance obtained with biosorbents. These, as well as other important aspects linked to biosorption, are fully covered in the present review.

Water contamination is an environmental burden for the next generations, calling for advanced methods such as adsorption to remove pollutants. For instance, unwanted biowaste and invasive plants can be converted into biosorbents for environmental remediation. This would partly solve the negative effects of invasive plants, estimated at 120 billion dollars in the USA. Here we review the distribution, impact, and use of invasive plants for water treatment, with emphasis on the preparation of biosorbents and removal of pollutants such as cadmium, lead, copper, zinc, nickel, mercury, chromate, synthetic dyes, and fossil fuels. Those biosorbents can remove 90–99% heavy metals from aqueous solutions. High adsorption capacities of 476.190 mg/g for synthetic dyes and 211 g/g for diesel oils have been observed. We also discuss the regeneration of these biosorbents.

Contamination of waters, soils, sediments and other environmental media by steroid estrogens is an emerging health issue because estrogens exhibit toxic effects on fishes and animals. Levels of steroid estrogens vary widely, ranging from below the detection limit to hundreds of nanograms per liter. Estrogens alter hormone levels and the homeostasis system of living organisms, they increase the risk of cardiovascular diseases, prostate cancer and breast cancer in humans and they may induce reproductive disorders, fetal malformations and feminization of males. Here, we review detection methods of steroid estrogens in water samples. Methods mainly include chemical analysis, immunoassays and bioassays. Advanced sensors increase the selectivity and sensitivity of electrochemical assays. For instance, graphene-based sensors can decrease the detection limit to 50 fM, though estrogen analogues may interfere. Immunoassays such as ELISA have the advantages of high sensitivity, fast analysis speed and wide applicability from 2 to 4000 ng/L, though it is susceptible to cross-reactivity.