Research on the Synthesis of Zinc-Ammonium Phosphate Using Galvanic Waste Sludge as a Source of Zinc.

This paper presents the extraction of zinc ions from waste resulting from the galvanic industry, such as sludge from acid zinc electroplating baths, and their revaluation in mineral fertilizer as zinc-ammonium phosphate. The purpose of this work is to extract zinc ions from the sludge that forms directly in the zinc bath, which can only contain zinc and small amounts of iron, to revalorize zinc into the form of zinc-ammonium phosphate. The process of obtaining zinc-ammonium phosphate is presented using waste sludge from the galvanic industry. In order to obtain zinc-ammonium phosphate, the solution resulting from the dissolution of the sludge with a 20% hydrochloric acid solution was used in reaction with diammonium phosphate and a 25% ammonia solution. After the chemical analysis of the obtained products, zinc-ammonium phosphate was characterized using X-ray powder diffraction, infrared FT-IR spectroscopy and electronic microscopy (SEM) analysis. The results obtained indicate a promising approach to sustainable resource utilization in the production of zinc-ammonium phosphate.

Evaluation of Phosphopolyoxometalates with Mixed Addenda (Mo, W, V) as Corrosion Inhibitors for Steels.

Nowadays, choosing a corrosion inhibitor is not only based on efficiency, but must also consider the toxicity of the compound, the impact on the environment, and, obviously, the regulations in the field. In the last two decades, a special class of substances has begun to be studied, namely polyoxometalates (POMs). Their electronic properties and redox characteristics make the polyoxometalates potential candidates to be used in many electrochemical processes, and as potential corrosion inhibitors. Electrochemical methods such as a Tafel extrapolation plot, chronopotentiometry, or gravimetry have been used to establish the capacity of corrosion inhibition of S235 and SS304 steels in the presence of phosphovanadomolibdate acid (@PMoV) and phosphovanadotungstate acid (@PWV) in 0.5 M sulphuric acid solution. The inhibition efficiency for S235 steel is about 90.6% for @PMoV, and 69.5% for @PWV after 24 h of immersion. In the case of SS304 steel, polyoxometalates have similar effects: the inhibition degree, as a function of Flade potential, is 4.66 for @PMoV; better than 3.26 for @PWV, with both proving the passivant effect.

Colloidal Gold Immunochromatography and ELISA Traceability of Tetracycline Residues from Raw Milk to its Dairy Products.

BACKGROUND/AIM: The presence of tetracycline (TC) and its residues in raw milk and milk dairy products poses a threat to human health due to the induction of antibiotic resistance of bacteria that can be transmitted between animals, humans, and the environment. The aim of this study was to investigate the transfer of TC from raw milk to different dairy products: pasteurized milk, boiled milk, sour milk, skimmed milk, and cottage cheese. We analyzed samples of milk from different sources: household farmers, local farms, and milk factories. MATERIALS AND METHODS: The analyses of TC in milk and dairy products were performed using colloidal gold immunochromatography assay (GICA) and enzyme-linked immunosorbent assay (ELISA). RESULTS: The highest content of TC was found in the milk purchased from local household farmers; therefore, these samples were chosen for the study of TC transfer to dairy products. TC was also found in sour milk at levels comparable with those obtained in raw milk. The average TC content decreased following heat treatment of the milk, as follows: for pasteurized milk 22.07% and for boiled milk 29.35%. The highest concentrations were determined in cottage cheese in the range 200-620 µg/kg. CONCLUSION: TC residues are transferred from milk to dairy products in various amounts depending on the preparation conditions, and due to their chemical properties, they accumulate in concentrated derivatives, such as cheese. Therefore, TC can be identified even in cheeses prepared from milk with undetected antibiotic levels.

Electrochemical strategies for gallic acid detection: Potential for application in clinical, food or environmental analyses.

Polyphenols are important to human health thus making it interesting and necessary to identify and assess methods for their detection. Gallic acid (GA) is a well-known antioxidant compound, found in tea leaves, various fruits, fruit seeds and in fruit-derived foods and beverages. In this study, to electrochemically detect this compound and assess the potential for GA detection, different analytical conditions at pH values of 5.8, 7 and 8 were tried. Two types of device were used for GA detection: (1) Lazar ORP-146C reduction-oxidation microsensors, coupled with a Jenco device, for estimation of antioxidant capacities of different electroactive media, and (2) screen-printed carbon sensors coupled with a mobile PalmSens device using differential pulse voltammetry (qualitative and quantitative GA determination). These proposed methods were validated by analysing some real samples: wine, green tea, apple juice and serum fortified with GA. Detection was evaluated in terms of specific calibration curves, with low limit of detection (LOD) and limit of quantification (LOQ), low response time, and high sensitivities. The analytical characteristics obtained recommend these methods to be tested on more other types of real samples. Our proposed methods, used in the established conditions of pH, may have further application in other clinical, food or environmental samples analyses in which the results of total antioxidants contents are usually expressed in GA equivalents.

Orchard management under the effects of climate change: implications for apple, plum, and almond growing.

The authors analyzed certain species and varieties of fruit tree in which applied crop technology is used and also undergoes the effects of climate change. The aim is to extend productive crop varieties, resistant to disease and pests, in order to obtain superior yields. The research was conducted in orchards located in northwestern Romania (on 8.59 ha), intensively cultivated with apple, plum, and almond species. The blooming period of the species and fruit production was studied in 2009, the first year of the farm's commercial production, and then compared to figures from 2016 to see the changes that occurred. Climatic conditions were studied throughout the period of existence of the farm (2002-2016). To determine the influence of the climatic factor on the blooming and production periods, respectively, every year is considered having pre-blooming, blooming, and ripening periods. It was found that climate change influences the annual biological cycle of the trees: the vegetative rest period of the trees shortens, the tree vegetation begins earlier in the spring, and the blooming period is advanced by as much as 10 days compared to normal cultivated varieties. All these factors have direct repercussions on the quantity of production.