Water quality is assessed through the biological, physical and chemical parameters. The limits of these parameters that are harmful to human health have been established at national or international level (WHO, EPA, MECC) by various laws, regulations, normative. An efficient and simplified to express the quality of water for consumption is given by the water quality index. It reflects the quality of water in a single value by comparing data obtained from the investigation of a number of physico-chemical and bacteriological parameters with existing limits. This number is placed on a relative scale to justify the quality of water in categories ranging from very poor to excellent. In this study are discussed various water quality indices used to assess the quality of drinking water (surface water). National and international agencies involved in assessing water quality and pollution control defines different quality criteria used for drinking water which is why there are many water quality specific indices for each region or area. In this context, it will present a comparative study of the most important quality indices used to assess water quality worldwide.

The presence of pharmaceuticals in the aquatic ecosystem has received great attention from the scientific community in the last decades, due to their potential impact on living organisms. This paper presents a short review of the results of investigations performed by INCD-ECOIND concerning the occurrence of 32 pharmaceutical compounds belonging to important therapeutic classes and 2 disinfectants along the Danube River and its tributaries. Grab water samples were collected from multiple points along the River (10 sites) and from 2 locations for each of the tributaries Jiu, Olt and Argeș, upstream and downstream of large cities. All samples were quantified via solid phase extraction, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results of these studies show that various pharmaceutical compounds are present in the dissolved water phase of the Danube River and its tributaries in low to moderate amounts with variation due to season and location.

The Danube River is the major source of drinking water supply for the cities in the southern part of Romania. The study was a descriptive-analytical one and lasted for 9 month. Samples were taken monthly between March 2016 and November 2016. Six sampling sites were selected to evaluate the spatial and temporal changes of water quality along the river. The samples were analyzed based on the standard methods for the following parameters: pH, conductivity (EC), NH4+, NO3-, Cl -, suspended solids, PO43-, SO42-, metals (Fe, Cd, Cr, Pb, Ni, Hg, As, Zn, Cu, Mn). The obtained values were compared with those imposed by the Romanian environmental legislation. An efficient and simplified method to express the quality of water used for consumption is provided by the Water Quality Index (WQI). WQI reflects the quality of water in a single value by comparing data obtained from the investigation of a number of physico-chemical parameters to the existing limits. The evaluation of water quality was performed using the Water Quality Index of the Canadian Council of Ministries of the Environment (CCME WQI). Water quality indices were classified as: excellent, good, medium, bad and very bad. The results indicated the water quality classification as �good� in all six sampling selected sites.

A simple, reliable and accurate HPLC/CAD method was developed for the determination of anionic (sodium dioctyl sulfosuccinate and sodium 1-dodecane sulfonate), amphoteric (CHAPS (3-[(3-Cholamidopropyl) dimethylammonium]-1-propanesulfonate hydrate)) and cationic (benzethonium chloride) surfactants mixture from surface water samples. The chromatographic analysis was performed on an Acclaim Surfactant Plus (150 x 3.0 mm, 3 mm d.p.) column acquired from Thermo Scientific, kept at 300C. All experiments were performed in gradient elution conditions at a flow-rate of 0.6 mL/min. Mobile phase composition was a mixture of acetonitrile (A) and 0.1 M ammonium acetate solution acidified to pH 5 with acetic acid (B). The limit of detection (LD) were 20 mg/L for anionic surfactants and 30 mg/L for cationic and amphoteric surfactants. The calibration curves were linear between 15 mg/L � 110 mg/L, with R2 values above 0.992 for all surfactants. Solid phase extraction (SPE) using polymeric (Strata X) cartridges has been applied to extract and concentrate the target analytes from the synthetic samples. Surfactants recoveries after SPE procedure were situated between 91.5�94.6%. Intra-day and inter-day precision (RSD%) were situated between 4.0 � 7.7% and 7.5 � 11.7%, respectively. Limit of quantitation (LQ) was lower than 80 mg/L for anionic surfactants and 90 mg/L for cationic and 100 mg/L for amphoteric surfactants. The new sensitive and selective HPLC/CAD developed method allows simultaneous determination of anionic, amphoteric and cationic surfactants mixture from environmental samples (surface water).

No abstract