Iron and manganese removal from drinking water

The purpose of the present study is to find a suitable method for removal of iron and manganese from ground water, considering both local economical and environmental aspects. Ground water is a highly important source of drinking water in Romania. Ground water is naturally pure from bacteria at a 25 m depth or more. However, solved metals may occur and if the levels are too high, the water is not drinkable. Different processes, such as electrochemical and combined electrochemical-adsorption methods have been applied to determine metals content in accordance to reports of National Water Agency from Romania (ANAR). Every water source contains dissolved or particulate compounds. The concentrations of these compounds can affect health, productivity, compliance requirements, or serviceability and cannot be economically removed by conventional filtration means. In this study, we made a comparison between the electrochemical and adsorption methods (using membranes). Both methods have been used to evaluate the efficiency of iron and manganese removal at various times and temperatures. We used two membrane types: composite and cellulose, respectively. Different approaches, including lowering the initial current density and increasing the initial pH were applied. Reaction kinetics was achieved using mathematical models: Jura and Temkin

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