The main purpose of this study was to investigate whether meteorological parameters (temperature, relative humidity, direct radiation) play an important role in modifying the NO2 concentration in an urban environment. The diurnal and seasonal variation recorded at a NO2 traffic station was analyzed, based on data collected in situ in a Romanian city, Braila (45.26° N, 27.95° E), during 2009–2014. The NO2 atmospheric content close to the ground had, in general, a summer minimum and a late autumn/winter maximum for most years. Two diurnal peaks were observed, regardless of the season, which were more evident during cold months. Traffic is an important contributor to the NO2 atmospheric pollution during daytime hours. The variability of in situ measurements of NO2 concentration compared relatively well with space-based observations of the NO2 vertical column by the Ozone Monitoring Instrument (OMI) satellite for most of the period under scrutiny. Data for daytime and nighttime (when the traffic is reduced) were analyzed separately, in the attempt to isolate meteorological effects. Meteorological parameters are not fully independent and we used partial correlation analysis to check whether the relationships with one parameter may be induced by another. The correlation between NO2 and temperature was not coherent. Relative humidity and solar radiation seemed to play a role in shaping the NO2 concentration, regardless of the time of day, and these relationships were only partially interconnected.

Sewage sludge resulted from urban wastewater treatment plants is generally accepted as a valuable source of nutrient and soil conditioner for agricultural usage. Analysis of amount of heavy metals in sewage sludge is essential previous to utilization of the sludge to agriculture considering the inevitable risk of heavy metal toxicity to soil, vegetation and humans. The present paper aims to analyse the characteristics of the sewage sludge resulted in an urban area for 5 years. Sewage sludge generated from five wastewater treatment plants in the South and South Est part of Romania were analysed.

This article investigates the efficiency of phosphorus removal in the municipal wastewater treatment plants in five counties of Romania from 2013 to 2017. This study focused on evaluation of the performance of phosphorus elimination using biological methods in order to respect the admissible effluent discharge limits. The yearly average of inflow total phosphorus varies from 3.64 mg/L to 4.22 mg/L comparing with 1.02 mg/ L and 1.59 mg/L the average of outflow. Chemical and biological methods are utilized to remove phosphorus. The efficiency of the numerous process available for the phosphorus removal is quite inadequate by comparing the effluent degree of purification and the removal cost.

Coffee is one of the most widely consumed beverages. Roasting is a baseline step in coffee processing, being involved in the development of color, flavor and taste for which coffee is appreciated. In addition, the roasting treatment triggers several complex physical changes inside the coffee bean, resulting in density decrease owing to volume increase, increase of beans brittleness, changes in coffee color, loss of bean mass and water, porosity increase, and governs coffee bean behavior during storage, grinding, and brewing. It is essential to examine physical changes, as coffee production is seasonal, and a long-term coffee storage is required. In the present study, the visual and microstructural differences between green and roasted Arabica coffee beans were investigated. The study of microstructural differences was performed using scanning electron microscopy, and clearly showed significant structural differences between green Arabica coffee beans and roasted Arabica coffee beans. The physical and structural modifications of infused coffee with water were explained through chromatic evaluation and microscopic analysis, respectively as function of ground size of roasted coffee beans and infusion time.

The article focuses on the evaluation of PM2.5 and PM10, pollutants resulting from the metallurgical industry in Romania. The analysed period is 2008-2018 and the dataset was provided by the National Institute of Statistics. The purpose of this paper is to examine the impact of final energy consumption in the metallurgical industry on PM10 and PM2.5 emissions. We included in the study three fundamental factors: the final energy consumption in the metallurgical industry and the particulate matter (PM10 and PM2.5). The average of PM10 for reference period is 4026 Tone (Mg) while for the PM2.5 the average is 3645 Tone (Mg). The trend of final energy consumption in the metallurgical industry is identical to the trend of PM2.5 and PM10, which indicates that this factor has a major influence on the amount of PM2.5 and PM10 emissions. PM2.5 and PM10 emission factors represent primary emissions from the metallurgical industry activities and do not consider the formation of secondary aerosol from chemical reaction in the environment afterwards the discharge.