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.

The cyclic variance of PM10 mass concentration in the urban area in the South-East of Romania has been analysed in the article. SE of Romania is considered to be a territory which has medium level of pollution for a period of last ten years, from 2009 to 2018. The spatial dispersion of PM10 concentration was obtained using the METI-LIS soft wear for each season. The objective of dispersion models is to evaluate how pollutant concentration is spread out taking into account the diffusion. The average measurements of PM10 and meteorological parameters as inputs has been used. An evident seasonal change of PM10 concentrations is observed in the article. In order to establish national measures for the improvement of the atmospheric pollution control it was analysed the mechanism of atmospheric pollution. It was observed that the air quality was overall better in spring and in summer in comparison to the other two periods. With regard to the seasonal variation characteristics of PM10 significant differences for the air quality registered in different months in the researched region were observed. The impact of air temperature on atmospheric pollution was insignificant in spring and autumn; moreover, precipitation was defined as an important influence factor upon the atmospheric pollution. The impact of precipitation on the possibility of atmospheric pollution was obviously different in the four seasons. The research results indicate the meteorological parameters that influence the air pollution become active during the cold seasonal days. It was shown that relative humidity and wind speed are the meteorological parameters that impact the PM10. It was found out that the probability of atmospheric pollution decreased with the increase of air temperature in summer. The research results also testify that the air pollution mapping could be enhanced using atmospheric dispersion models and in-situ measurements.

Nitrate is ordinarily found within the ecosystem, as part of the nitrogen cycle. The anthropogenic inputs have highly increased nitrate loads into ground and surface waters. All these factors have had a drastic impact on aquatic environment, human health and flora and fauna. Hence, the identification of nitrate sources is valuable in conserving water quality and achieving sustainability of the water resources. The present paper aims to present a clearly image of water pollution in South and South Est part of Romania. The dataset for ammonium (NH4+), total nitrogen (Ntot) and nitrite (NO2-) was collected from 2013 -2017.

An appropriate appraisal of the water quality parameters has an essential contribution in identification of main pollution factors in a certain region. In Romania, the lower course of Danube River Basin covers more than 1,075 kilometres and a significant percentage of the population lives in this area and depends on the Danube for potable water, industry, agriculture, and transport. The biodiversity, species and habitats, is markedly significant, taking in account that the Danube is the largest uninterrupted wetland area in the world and one of the last relatively undisturbed regions of Europe. The main focus of this article is to analyze the capability of chlorine removal in the municipal wastewater treatment plants in five counties of Romania, starting from 2013 to 2017. The five years average of influent fluctuates from 77.56 mg/dm3 to 111.03 mg/dm3 comparing with 82.94 mg/dm3 and 116.29 mg/dm3 the average of effluent. It should be specified that the limit imposed by the European legislation is 500 mg/dm3. Even if the measured values are below a quarter of the imposed limit, chlorinated wastewaters can be poisonous and may have a harmful impact on aquatic flora and fauna that are exposed to them, and consequently, that chlorination dechlorination might not be appropriate treatment approach for the protection of receiving waters.