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.

The soil cover is subject to anthropogenic changes as well as other geoecosystems subjected to pressures due to sources. The results are recorded for the soil cover depending on the type of anthropogenic manifestations, intensity, nature, and number of their manifestations. Moreover, the interferences with the natural landscapes intervene, and from here appear the evaluation process difficulties. In most cases, it is considered that the urban landscape is distinguished by a series of peculiarities regarding the quality of the urban hydrosphere, an atmosphere, and the biosphere, as well as a series of changes in the pedosphere, as a result of land use. Notable for the soil cover, being particularly important is the soil cover the surface of the pedosphere. The complex of ecological parameters can provide important information on the flows and balance within the ecological system. The ecological importance of urban soils has long been underestimated. Urban soils were protected only as a support for construction. It was not until the early 1970s that the first approaches to the study and classification of urban soils were initiate. We can say that in 2020 the situation is completely different, in the sense that urban soilsare studied and evaluated periodically in terms of quality.

The research aimed to provide an optimized method for the determination of phosphorous concentration in different types of solid waste using inductive coupled plasma mass spectrometry (ICP-MS) technique. The analyzed waste matrices are: a) vegetable waste (P1), b) ash from the incineration of medical waste (P2) c) sewage sludge (P3) and d) sludge from the meat processing industry (P4). The results obtained by the ICP-MS method were compared with the UV-VIS spectrophotometric method for the determination of total phosphorus. In the case of using the colorimetric method by UV-VIS technique, lower results were obtained compared to the ICP-MS method due to the interferences given by the reagents used to determine the total phosphorus. The interferences given by other elements (metals) were also investigated and the performance parameters were determined such as detection limit, quantification limit, recovery and expandend incertainty using ICP-MS technique.

The paper presents the chemical fractions and leaching of the heavy metals in the bottom and filter ashes from the incineration of medical waste by two comparative methods of sequential extraction and by Toxicity Characteristic Leaching Procedure test (TCLP). The BCR classic method has higher extraction percentages than proposed modified BCR method. In both ashes, the metals are predominantly bounded in F1 (exchangeable) and F2 (iron and manganese oxides) fractions. Due to the high content of metals in filter ash, representing over 17,000 mg/kg dry matter for Zn, 7,000 mg/kg dry matter for Pb, and 1,400 mg/kg dry matter for Cr and Cu in F1 and F2 fractions, a special attention should be given to the management and storage of this waste.

In this study the removal of Mn (II) ions from wastewater using magnetite nanomaterial was investigated. Some factors influencing the wastewater treatment process were studied such as: treatment time, pH and the concentration of Mn (II) ions from wastewater. The results showed that using magnetite nanomaterial adsorbent lead to a wastewater treatment efficiency higher than 97%. Langmuir and Freundlich models were applied to describe the adsorption process. The correlation coefficients (R2) showed that both models are applicable to the experimental data obtained.