RJEEC, Volume 2, no. 2, 2020

In the paper are presented the results of tests on the evaluation of the level of noise and chemical air pollution in two distinct urban areas: an industrial area and an area characterized by heavy road traffic, with a focus on the novelty elements introduced by the regulations in force on the measurement and management of the level of ambient and industrial noise by periodically developing specific noise maps. The results of direct tests and noise maps developed in the case of the studied areas indicated higher values of the indicators measured in the immediate vicinity of the road artery compared to the other measuring points, highlighting the influence of vegetation in urban areas to reduce noise levels and reduce air pollution.

The chemical behavior of groundwater is one of the most dynamic areas of environmental research. In the present study, groundwater sampling from different locations in the north-west area of Romania was performed in order to assess groundwater chemistry and compare water types using Distribution maps. Groundwater chemistry has been evaluated and natural processes are identified as control factors for hydrochemistry. The Piper diagram was created to compare the results of water types. Chemical analysis of groundwater was used to calculate the values of the water quality index. Romanian drinking water standards EPA 485-2002 and WHO standards were taken into account when calculating the WQI. The SAR index was used to evaluate groundwater samples in the study area for irrigation purposes. The classification of water types based on WQI values for each groundwater sample shows that 80% of the analyzed samples can be used as drinking water resources, the rest of 20% is intended for irrigation.

Surface water contamination by synthetic dyes generates human and wildlife adverse health effects and causes photosynthesis decrease due to intense sun-light absorption of these pollutants. 50% of total discharged industrial effluents contain azo dyes. Congo Red is a benzidine based anionic azo dye that is usually employed in rubber, paper, and plastic industries. Congo Red can cause eye and skin irritation and is potentially carcinogenic in nature. This study explores the development of a new HPLC method to detect synthetic dyes in residual waters coming from wastewater treatment technologies based on magnetic material adsorption. Cobalt ferrite (CoFe2O4) and chitosan coated cobalt ferrite (CoFe2O4-Chit) prepared by a simple co-precipitation method were tested as adsorbents for Congo Red (CR). Effect of contact time, solution pH, and initial dye concentration were studied with respect to Congo Red adsorption efficiency. The adsorption experiments were performed at pH = 4.5 and 10.8. Highest value for the removal efficiency using magnetic material of cobalt ferrite coated with chitosan (CoFe2O4-Chit) was obtained at pH 10.8

Environmental pollution is an important issue influencing human health and environmental equilibrium. The range of pollutants is very wide due to industrialization and population growth and surfactants are one of the most common organic pollutants due to their extensive use and ubiquitous presence from industry to households. Their massive presence in the domestic and industrial wastewater could affect the Wastewater treatment plants by inhibiting the activated sludge used in pollutants biodegradation treatment step. This paper aimed to study the inhibition effect of three classes of surfactants (nonionic, anionic, and cationic) by measuring the respiratory activity of microorganisms with the application of the Oxygen Uptake Rate (OUR) test. This study established that the surfactants could activate or inhibit microorganisms’ activity, depending on surfactant concentration.