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.

This paper presents aspects of monitoring material dust emissions from stationary emission sources (monthly dust measurements performed on cement mill stacks—mill outlet and separator outlet). Additionally, the Portland cement mill technological process (its component parts), as well as the solutions regarding the reduction of the air emissions level, following the emission limit values (VLE), established in the integrated environmental authorization (AIM) from a cement factory in Romania, were analyzed. The paper focused on analyzing the data obtained in three different years for PM10 and dust concentrations (2018–2020). For each year, the measurements have been done in 3 months, each in a different season. The average values for each year for working conditions were: 30.22 mg/m³ (2018), 27.38 mg/m³ (2019), and 27.51 mg/m³ (2020) for working conditions and for normal conditions: 34.22 mg/m³ (2018), 30.49 mg/m³ (2019), and 30.16 mg/m³ (2020). For all 3 years, the values measured in spring were higher than the other two, both for work and normal conditions.

From the available statistical data, cement factories co-process a range of over 100 types of waste (sorted both industrial and household) being authorized for their use as combustion components in clinker ovens. Therefore, the level of emissions is different depending on the type of fuels and waste used. The amount of industrial and municipal co-processed waste in the Romanian cement industry from 2004 to 2013 was about 1,500,000 tons, the equivalent of municipal waste generated in a year for 18 cities with over 250,000 inhabitants. The objective of this paper was to evaluate the emission level of hydrochloric acid (HCl) and hydrofluoric acid (HF) at the clinker kilns at two cement factories in Romania for different annual time intervals and to do a comparative analysis, to estimate their compliance with legislation in force. The measurements results showed average emission levels of about 0.578 mg/Nm³ for HCl and about 0.100 mg/Nm³ for HF, in the first hours of the evening, but decreased at the beginning of the third tour, at about 0.385 mg/Nm³ for HCl, respectively, to about 0.085 mg/Nm³ for HF. The evolution of HCl and HF emission levels during the last 4 years showed a variable distribution of these acids.

Worldwide, in the rotary kilns of cement plants, various amounts of combustible waste are burned, which would otherwise end up in municipal landfills. The paper first analyzes the literature on the co-processing of waste in cement manufacture and its influence on the environment and human health. Then, it shows how the combustion components of co-processed waste can influence the final characteristics of clinker and cement. The main objective of the paper is to determine the level of emissions of the resulting pollutants (total dust and flue gases: NOx, SO₂, and CO) at the outlet of the chimney of the clinker kiln and flour mill to meet the requirements of the Integrated Environmental Permit (EIA) from Romania and present an estimation of the level of atmospheric air pollution using the climatological model of pollutant dispersion. Following these assessments (data shown), the cement factories will establish measures to reduce the pollution, if necessary, to comply with the regulations in force for the cement industry.

Electricity comes from many sources, each with its own advantages and disadvantages. Availability and environmental impact are two of the most important criteria that will tilt the balance in favor of renewable energies, at the expense of fossil fuels, exhaustible and polluting resources for the environment. Green energy obtained from solar energy with the help of photovoltaic panels is topical and in great demand during this period. Whether it's household consumers, private companies or public authorities, everyone wants to get rid of energy bills. Technological advancement has substantially increased the efficiency of photovoltaic systems, from panels to inverters and equipment for management, reporting and remote action. Thus, the present work presents a management plan that includes the steps that an applicant must go through in the field of photovoltaic panels, from the idea to the commissioning of the photovoltaic park. Each stage is presented in detail. Also, the advantages and disadvantages of implementing a photovoltaic park are presented, becoming a guide that helps future applicants in this field. It also presents possible questions that an applicant may ask, as well as the answers to them, so that if an applicant is unclear, this paper will provide him with the details he needs.