Springer Science and Business Media LLC

Dust is a serious worldwide pollution, notably for nanoscale particles that are both toxic and difficult to control. Dust suppression can be done by adsorption on solid wastes, such as collagen from by-products of leather manufacturing. Here we review dust pollution and dust control, notably using collagen degradation products. Simulation experiments show that dust suppression using modified collagen degradation products reaches 68.2% for particulate matter 2.5 (PM2.5) and 78.7% for particulate matter 10 (PM10). The advantages and disadvantages of the current dust suppressors are discussed.

In 2010 the pond dam of an aluminium manufacturing plant in Hungary broke and flooded many towns with toxic red mud. At least 10 people were dead and over 150 hospitalized. Bauxite residue is often referred as red mud due to the colour of the bauxite ore and iron oxides. Red mud is separated during the refining process. The production of 1 t of alumina generally results in the creation of 1–1.5 t of red mud. Red mud is toxic for the environment due to high alkalinity, salinity and trace metals. Here, we used the plant Arundo donax L. (giant reed) to uptake trace metals and decrease salinity and pH of red mud. We measured plant toxicity, trace metal availability and biomass production. Results show a 25 % decrease in electrical conductivity of red mud and a 6 % decrease in electrical conductivity of mud-polluted soil. Giant reed cultivation decreases available Cd, Pb, Co, Ni and Fe. Biomass of giant reed seedlings in red mud and mud/control soil mixture was increased by 40.4 and 47.2 %, respectively, comparing with control soil. Our findings show that giant reed is promising to decontaminate soils contaminated by red mud.

Hydroxyl radicals are commonly produced either by metal activation or by using external energy. However, the application of these methods is limited by low working pH and secondary contamination with metal ions. Alternatively, the reaction between hydrogen peroxide (H2O2) and hydroxylamine is an environmentally friendly process that generates active radicals, but the reaction rate is slow. To improve this, we report here a novel and efficient activator for the H2O2/hydroxylamine system that uses sulfate ions ($${\text{SO}}_{4}^{2 - }$$). We tested the effects of different systems, concentrations of H2O2, hydroxylamine and $${\text{SO}}_{4}^{2 - }$$, and pH on the degradation of Rhodamine B. The mechanism was also investigated by kinetic calculation, a radical scavenging experiment, and anions comparison. Results show that the addition of $${\text{SO}}_{4}^{2 - }$$ effectively improved Rhodamine B degradation and widened the working pH. The hydroxyl radical was found to be the primary radical responsible for dye degradation. Moreover, only $${\text{SO}}_{4}^{2 - }$$ shows an enhanced effect under the same ionic strength conditions. Overall, our findings reveal a new method for water purification at acidic and near-neutral pH, especially for sulfate-rich wastewater treatment.

Pure and drinkable water will be rarer and more expensive as the result of pollution induced by industrialisation, urbanisation and population growth. Among the numerous sources of water pollution, the textile industry has become a major issue because effluents containing dyes are often released in natural water bodies. For instance, about two years are needed to biodegrade dye-derived, carcinogenic aromatic amines, in sediments. Classical remediation methods based upon physicochemical reactions are costly and still generate sludges that contain amine residues. Nonetheless, recent research shows that nanomaterials containing biopolymers are promising to degrade organic pollutants by photocatalysis. Here, we review the synthesis and applications of biopolymeric nanomaterials for photocatalytic degradation of azo dyes. We focus on conducting biopolymers incorporating metal, metal oxide, metal/metal oxide and metal sulphide for improved biodegradation. Biopolymers can be obtained from microorganisms, plants and animals. Unlike fossil-fuel-derived polymers, biopolymers are carbon neutral and thus sustainable in the context of global warming. Biopolymers are often biodegradable and biocompatible.

Biological effects of nanoparticles have attracted widespread attention. However, the interaction between plants and nanoparticles remains unclear. The purpose of this study was to investigate characteristics of nano-sized metal particles in two representative plant species, Erigeron canadensis and Boehmeria nivea, in the Guangdong Province, China. The stems of the plants were sliced and placed on Ni–C grids for field-emission transmission electron microscopy (TEM). The metal-bearing nanoparticles were further analysed for their size, shape, composition, content and other characteristics using X-ray energy spectrum analysis, scanning TEM and selected-area electron diffraction pattern. The results revealed that the plants contain nano-sized Au-bearing particles with a diameter of 5–50 nm, ellipsoid, spherical and bone-rod shapes or irregular morphology with smooth edges. These nanoparticles primarily consisted of Au, Cu, O and Cl. The discovery of Au-bearing nanoparticles in natural plant tissues is of great significance for biological nanoscience. Here, we discuss the function and absorption mechanism of Au-bearing nanoparticles in plants and present the influence of the discovery of Au-bearing nanoparticles in natural plants.