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Around the globe there are a large number of people who are not at the receiving end for clean drinking water and the explanation for this major scarcity is advancements in industrialization. The industrials residues include many toxicants and heavy metal ions among which arsenic has some of the worst effects on human beings as well as the environment owing to its carcinogenic nature and accumulative characteristic. Even a slight exposure to can cause devastating effects. The highly hazardous nature is the explanation for arsenic becoming a target metal in water treatments. The environment cannot handle yet another by product that would pose as some other threat and hence the objective is to land on an ecofriendly, efficient and cost effective resolution. The adsorptive alternative with the employment of ZnO posed as a competent candidate for the green resolution of water treatment. This paper portrays a picture of arsenic elimination and its dependence on certain process parameters along with some external material incorporation and structural variations into composites, nano scale rods, spheres, tubes etc. that are known to manifest an inclination towards higher performance of nanoadsorbents. [ABSTRACT FROM AUTHOR]

It summarizes strategic analyses regarding the future of copper concentrate exports, its problems and Chile's participation not only as a global copper producer, but as a refined copper producer. These analyses aim to develop a basis for modernization and possibly the construction of new foundries in Chile; are considered economic, competitive and strategic aspects. In Chile, an increase in the production of copper sulfide concentrates is projected, considering the depletion of oxidized minerals. This increase also includes complex or dirty concentrates with a high presence of impurities, mainly arsenic. Currently in an environmental context, Chilean smelters on average do not meet the emissions standard for copper smelters due to the age of these smelters and the high investment required to modify their infrastructure. Strategically, the increase in high impurities in concentrates results in higher treatment costs, penalties and difficulty of acceptance in the international market. With regard to the economic context of these smelters in Chile, these are among the most cost of operation worldwide. A globalized strategy for the modernization of foundries in Chile is therefore needed. High-capacity foundries are recommended, which will have state-of-the-art technology to eliminate arsenic and capture emissions and are also fed by mixtures of concentrates from different mines, with the participation of Codelco and private miners. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) were synthesized using allyl mercaptan (C3H6S) as the capping agent. It was expected that high affinity of gold to groups containing S as well as double bonds in allyl mercaptan structure can be used to form covalent bonds between AuNPs onto the BDD surface. The characterization of AuNPs using a UV-Visible Spectrophotometer produced specific wavelengths of gold nanoparticles in the range of 510–580 nm, while characterization using Transmission Electron Microscopy (TEM) and Particle Size Analyzer (PSA) showed an average size of AuNPs at 29 ± 5 The synthesized AuNPs were deposited on the surface of the BDD electrodes by immersion method under UV light (λ = 254 nm) and characterized using X-Ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS). Examination of arsenic sensor was carried out using the Anodic Stripping Voltammetry (ASV) technique. Measurements of As3+ using AuNPs-modified BDD (AuNPs-BDD) electrode showed current responses with good linearity (R² = 0.99) in the concentration range 0–100 μM with limit detection values of As3+ of 0.064 μM. [ABSTRACT FROM AUTHOR]

Modification of boron-doped diamond (BDD) with gold nanoparticles (AuNPs) has been developed for an arsenic sensor. The AuNPs was synthesized using garlic extract served as both the capping and reducing agents. The optimum mixture of preparation was 0.11 moles of Au from HAuCl4 in 4 µ g of garlic extract at pH 5 under 15 min UV irradiation. TEM Image showed that the average size of AuNPs was varied from 2–10 nm, which was also confirmed by UV-Vis spectra at 520 nm. Furthermore, the synthesized AuNPs were immobilized on the BDD surface by immersion technique under UV irradiation at 254 nm. SEM EDX showed that AuNPs-modified BDD with an Au:C ratio of 37:63 (wt.%) could be successfully prepared. Application of the AuNPs-modified BDD for detection of As3+ ions using anodic stripping voltammetry technique showed that green synthesized process of BDD modification was suitable to prepare an electrode for arsenic sensors. [ABSTRACT FROM AUTHOR]

Surface water pollution occurs due to urbanization of the environment and the growth of industries. Monitoring of the pollution´ sources, regular control as well as analyzing of surface water status in small streams is a basic prerequisite for good condition and water quality in the rivers into which they flow. The functioning of the water system includes processes that affect the surface water cycle itself, the reduction of selected characteristics, the removal of toxic substances, the protection of the ecosystem and the aquatic fauna. This paper aim is to monitor the surface running the stream Súčanka (Trenčín region, Slovakia) and its three tributaries the Krasín stream, the Černatina stream and the Poľníky stream. The paper summarizes the data quality of the running water surface based on selected physical-chemical and chemical characteristics. The values of the analyzed data are related to the pollution of the water stream and affect the purity of the surface water of the stream. These monitored characteristics were analysed in the samples of the surface running water, which has been removed from the twelve sampling places in 2015-2017. The following selected characteristics were analyzed: temperature, the reaction of water (pH), conductivity, fluoride, chloride, sulfate, ammonia, nitrite and nitrate nitrogen and heavy metals (arsenic, copper, nickel, and lead). From the analyses of selected characteristics the stream Súčanka and its tributaries streams implies the following: the values of the temperature of this watercourse, pH, the concentration of chlorides, sulfates, ammonia nitrogen, and heavy metal (As, Ni, Pb) are within the limit values of the current legislation and standards. Increased values of nitrate and nitrite nitrogen concentrations, which exceeded limit value were analyzed at two sampling places, in the mainstream Súčanka in the range of 7.95 mg.dm-3 even 11.60 mg.dm-3 and the stream Černatina, in the range of 30.50 mg.dm-3 even 32.10 mg.dm-3. From the results of analyses of heavy metal concentrations, the greatest variability was found in the value of Cu concentration at the beginning of the village Dolná Súča (39.30 μg.dm-3). Súčanka stream is not only an important regional hydric biocorridor but it is a trout fishing ground (district number 2- 2730-4-1). [ABSTRACT FROM AUTHOR]

Adsorption on a suitable adsorption material is among the most frequently used methods in water treatment. In terms of plant operation, filtration (sorption) process represents a simple, effective and economical friendly method of heavy metals removal namely for the possibility of using a large scale of substances with a sorption ability – sorbents. Oxides, oxyhydroxides and hydroxide containing iron are among the most frequently used sorbents of the heavy metals removal. The quality of the treated water (pH, silica, phosphorus, fluorides, sulphates, chlorides, vanadium, total mineralization, iron and manganese, organic matter, etc.), redox conditions and the valency has the impacts on heavy metal removing efficiency. The objective of this work was to verify the sorption properties of granular iron-based sorption materials (CFH12, Bayoxide E33) in removal of arsenic from groundwater source Santovka. The water source in the Santovka site (HVS-9 well with a concentration of As about 18 μg/L) and the addition of a certified reference standard so that the resulting arsenic concentration about 50 μg/L was used in laboratory experiments. [ABSTRACT FROM AUTHOR]