Matrix-type certified reference materials for quality control of metal determination from solid environmental and vegetation samples

In the context of monitoring environmental factors, metals are one of the major analytical components. Applying appropriate determination methods and obtaining accurate results is a requirement imposed on environmental laboratories that perform quality control of water, soil, waste or vegetation. This study presents some examples of certified reference materials for quality control of the results of toxic metal determination from solid environmental and vegetation samples. The analyzed and verified metals were As, Cd, Cr, Cu, Ni, Pb and Zn. The pre-treatment of the samples, the determination methods of metals and the obtained results are also presented. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-EOS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) techniques are suitable for low metal concentrations, while ICP-EOS and Flame Atomic Absorption Spectrometry (FAAS) methods can be used at high concentrations

Geochemical evaluation of soils, surface, and groundwater from natural protected areas from Romania. Case studies.

The purpose of this article was to present an assessment of the soil and water quality in some protected areas from Romania in order to establish a series of geochemical thresholds on a spatial and temporal scale. The activities and results presented in this article are based on extensive monitoring, being stage results because the monitoring activities will continue, the project is ongoing. Two protected areas, Cheile Nerei -Beusnita National Park and Piatra Craiului National Park were selected. Surface water, groundwater samples, and soil samples were collected in 2019, respectively 2021 from 16 sampling sites situated in both locations. For each sample, twenty quality parameters/indicators were analyzed and the values were compared with in-force legislations. For Arsenic, Copper, and Nitrates parameters were plotted the distribution of the values in each site. In future monitoring activities, the evolution of the parameters will be followed

Chemical characterization methods for biodegradable organic wastes with relevance for the composting process. Case study

The study aimed to develop some methods for the compositional characterization of biodegradable waste with relevance to the composting process at the laboratory level. For testing, four waste fractions were selected, such as waste based on dehydrated sludge, waste from parks (leaves, branches), market waste (mixture of vegetable and fruit) and cardboard waste. For metals and phosphorus, several microwave digestion methods were applied. The ammonium nitrogen content (NH4-N) was determined using a number of extraction procedures (water, CaCl2, and KCl). Three certified reference materials were used for testing the validity of the results. Recovery percentages higher than 90% were obtained. The developed and validated methods are suitable for biodegradable waste characterization used in composting processes

Ranking the dietary treatments of broiler chickens in order to reduce nitrogen pollution of the environment

The Analytical Hierarchy Process (AHP) methodology was used to rank the tested nutritional solutions and to choose the best nutritional solution in order to reduce environmental pollution with nitrogen. The evaluation methodology consisted in comparing by three evaluators the diets based on the zootechnical performances/thigh meat quality / environmental impact. The diets of tested nutritional solutions were contained either medicinal and aromatic plants (basil, thyme, sage) in a proportion of 1% (batch 2), respectively essential oils (0.05%) of the same plants (batch 1). The application of the AHP methodology indicated that the best nutritional alternative was obtained for basil, either in the form of essential oil or vegetal material

Sensitive bioindicator plants studies, under the environmental conditions of climate change impact

Air pollution is a serious problem in many heavily populated and industrialized areas in the world. It affects vegetation, and also human health. The diversification of emission sources, among them vehicles, industrial processes, waste burnings and fuel storage, creates zones with different species and concentrations of air pollutants. In this paper was studied the excessive accumulation of toxic metals such as Al, Cr, Ni, Zn, Pb in vegetation as a risk factor for ecosystem and also for human health. The purpose of the study was to establish an optimal method of determination for toxic elements accumulation in leaves, using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). These results made to suppose that, visible and analyzed responses of in in-situ exposed bio monitors compared with heavy metal accumulation depended on the atmospheric situation during the period of exposure, which could assess the efficiency of biomonitoring programs in the region. The advantage of this study consists in new and appropriate approach using a friendly methodology for air monitoring and favoring the development of a circular and sustainable economy

Removal of Metals from Aqueous Solutions Using Sea Buckthorn Waste from Dietary Supplement Technology

The purpose of this study was to produce additional data for the valorization process of vegetable waste originating from dietary supplement technology. Two types of vegetable waste originating from different technological processes of sea buckthorn oil were used: vegetable waste from organic solvent extraction (P1) and vegetable waste from cold extraction (P2). Batch experiments evaluated the influence of pH, initial metal concentration, contact time, and Langmuir and Freundlich adsorption isotherms. The following pollutants—Cu, Cr, Co, Ni, Pb and Zn—from the wastewater were studied. The removal efficiency of metals from wastewater was evaluated at pH 3, 5 and 7. The highest metals removal efficiency was obtained at pH 5. It was observed that the Langmuir isotherm fits the adsorption process very well. Based on the results obtained, it can be concluded that vegetable waste resulting from the sea buckthorn oil industry could have potential applications for removing toxic metals from wastewater due to its high removal efficiency (>80%)

Magnetite Oxide Nanomaterial Used for Lead Ions Removal from Industrial Wastewater

The aim of this article is to present a nonconventional method for the efficient removal of lead ions from industrial wastewater. For this purpose, magnetite nanomaterial was used, which was very easily separated from the wastewater at the end of the treatment due to its magnetic properties. Currently, nanotechnology is an efficient and inexpensive manner that is being researched for wastewater treatment. Additionally, iron oxide nanoparticles are widely used to remove heavy metal ions from water due to their special properties. The experimental results detailed in this article show the influence of pH and contact time on the process of adsorption of lead ions from wastewater. The magnetite nanomaterial had its maximum efficiency of speed when the wastewater had pH 6. At a lower pH, the highest treatment efficiency was over 85%, and the required contact time has doubled. When the pH increases above 6, the precipitation process occurs. Langmuir and Freundlich models were used to describe the adsorption process

Тяжелые металлы как примеси в байерном производственном цикле гидроксида алюминия из сьерра-леонбуксита. Предварительное исследование

This paper is reporting the data of a preliminary study on heavy metals distribution in the fluid and solid phases involved in dry and classified aluminium hydroxide production through Bayer process. For heavy metals released in the fluid phases, the main source of contamination is the bauxite through its mineralogical phases soluble or insoluble in alkaline solution. It was shown that predominant way to transfer contaminating elements in aluminium hydroxide particles is the occlusion of very fine particles coming from mineralogical phases of bauxite residue. New born mineralogical phases from bauxite residue, like poor crystallized sodalite and cancrinite, are the most active occlusion contaminantsВ этой статье приводятся данные предварительного исследования распределения тяжелых металлов в жидкой и твердой ф азах, участвующих в производстве сухого и классифицированного гидроксида алюминия в процессе Байера. Для тяжелых металлов, выделяющихся в жидких фазах, основным источником загрязнения является боксит через его минералогические фазы, растворимые или нерастворимые в щелочном растворе. Было показано, что преобладающим способом переноса загрязняющих элементов в частицах гидроксида алюминия является окклюзия очень мелких частиц, происходящих из минералогических фаз бокситового остатка. Новорожденные минералогические фазы из бокситовых остатков, такие как плохо кристаллизованный содалит и канкринит, являются наиболее активными загрязняющими примесям