The paper presents the quality status of 14 brands of bottled water, with sources of groundwaters from different mountain areas alongside the Carpathian Mountains from Romania. A number of 12 physico-chemical parameters (ammonium, bicarbonate, electrical conductivity, carbonate, chemical oxygen demand, chloride, nitrate, nitrite, pH, sulphate, total hardness, turbidity), 9 metals and metalloids (Li, B, Na, Mg, Al, K, Ca, Sr, Ba) and 17 heavy metals (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Mo, Ag, Cd, In, Tl, Pb, Bi) were determined and studied. The quality status, the potential contamination and the health risk assessment of bottled waters were assessed, by using the drinking water quality index, the heavy metal pollution index, the heavy metal evaluation index, the degree of contamination and the human health risk indices. Hierarchical cluster analysis was applied, indicating similarities among the studied bottled waters based on their metal content. The Piper diagram reveals that the majority of bottled water samples fall into the Ca, Mg, Na, K, Cl−, SO42−, CO32−, HCO3− categories. The quality of bottled waters based on the indices results indicated marginal, poor and very-poor quality status of the studied water samples, while the health risk assessment indices presented potential risks at aluminium, chloride and nitrate for the inhabitants who used those water samples with the purpose of drinking. The pollution indices with respect to metals generally reflected a low pollution status. This study represents the first attempt in assessing the overall quality of some bottled water collected from the mountain area, Romania, likewise assessing the comprehensive human health risk due to several chemical elements determined in water in amounts around and exceeding the maximum allowable concentrations. This research can be useful for development of potential strategies for risk control and management in the field of drinking water.

This paper presented a groundwater quality monitoring in Seini town, North-West of Romania, by assessing 18 physicochemical parameters (pH, EC, COD, turbidity, ht, NH4+, NO2-, NO3-, Cl-, Al, Fe, Mn, Pb, Zn, Cd, Cr, Ni and As) from 12 private dug wells and 5 private drilled wells, each with unique characteristics and used as a drinking water source. The pollution, quality status and risk assessment of drinking water sources were assessed, by pollution, quality and risk indices. Statistical methodology and cluster analysis were applied in order to elaborate and improve upon a mathematical model. 2 D and 3 D mathematical models were elaborated to show the functions that better describe the dependence between a set of physicochemical parameters. Heavy metal pollution index (HPI) and heavy metal evaluation index (HEI) results indicated that the studied drinking water sources presented no heavy metal contamination. Human health risk assessment indices showed that the consumption of studied waters presented no non-carcinogenic risk at heavy metals, but potential non-carcinogenic risk at NO3-. The water quality index (WQI) classifies the majority of samples as waters with excellent quality and the minority of samples in waters with poor and very poor quality. By geostatistical techniques, the spatial patterns of the main physicochemical indicators were established for both the surface of the aquifer and its depth. The aim of the water quality study was to establish the toxicity degree of water, its influence on human health and to inform the population regarding the use of individual water sources.

This paper focuses on the evolution of quality indicators (pH, turbidity, oxidizability) of raw water in the Firiza-Strâmtori barrier lake, in between April 2015 - March 2016, in correlation with atmospheric precipitation quantities. pH, turbidity and oxidizability analyses were conducted in the time span of one year, tracking the evolution of these parameters in regards to the monthly quantity of atmospheric precipitations. For a comprehensive representation, the quality indicators of raw water, at the entrance and exit of the Baia Mare treatment plant, are also followed.

The paper follows the spatial variability and seasonal evolution of the heavy metal content of the Firiza-Strîmtori Reservoir that is the main source of drinking water for Baia Mare city located in the northwestern part of Romania. Water samples were collected from 10 sampling points located along the median line of the lake at different depths (at surface, at 5 m, 10 m, 15 m and 20 m). The experiments were carried out in the winter, spring, summer and autumn of 2015. We determined the concentration – depth profiles, both for the heavy metals iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd), lead (Pb) and also for sodium (Na), potassium (K), calcium (Ca) and magnesium (Mg). We determined the concentrations of heavy metals by atomic absorption spectrometry. We found that concentrations of heavy metals increase with depth. Generally, the concentrations of heavy metals are within the legal limits for the water used as drinking water sources. Mathematical models with high correlation coefficients were obtained in the case of heavy metal concentrations depending on depth and also for the seasonality of heavy metals upload.

This study presents the evolution of specific parameters of raw water quality from the Stramtori-Firiza Lake, which is the raw water source of the water plant in Baia Mare town, Romania. Parameters such as temperature, turbidity, oxidability were recorded over a four years interval. A comprehensive database on the evolution of these water parameters was thus created showing the tendency of these parameters across time. The possible correlations among the parameters were investigated. Positive correlations were found for oxidability and Al content and also for turbidity and oxidability. Temperature and turbidity were found to be highly variable (2-17 degrees C, 3-53 NTU) across seasons. In order to improve the turbidity of treated water, two coagulants were tested: basic polyaluminum chloride (PAC) and aluminum sulphate (SA) evaluating the efficiency of the two treatment methods. While the traditionally used aluminum sulphate was found to be effective only when the temperature and turbidity were high: temperature > 10 degrees C, turbidity > 10 NTU (nephelometric turbidity unit), PAC emerged as an efficient clarifying agent even at low temperature and turbidity.

The paper presents studies regarding the water quality from the accumulation lake, characterised by higher turbidity in the studied period, and also the water treatment possibilities with new coagulation reagents (aluminium bases poly chlorines) and alkalisation, comparative with aluminium sulphate and calcium hydroxide, following the efficiency and inefficiency of those in the colloidal systems destabilisation and zeta potential reduction.

A series of all-solid-state electrodes sensible to the ionic (anionic and cationic) surfactants were developed using silver pills coated with PVC membranes. We used cetyltrimethylammonium laurylsulfate and tricaprylmethylammonium laurylsulfate as sensing materials (active substance). The electrochemical properties of the electrodes were studied and the functions of the electrodes were tested. We selected the best membrane composition considering the best slope and the largest linear response domain. The membrane composition with the best electrochemical characteristics was that based on tricaprylmethylammonium laurylsulfate plasticized with dioctylsebaccate (nearnerstinan slope: 58,56 mV/pC and concentration range of linear response 5x10-2x10 M of laurylsulfate). The electrode function of these electrodes presents an abrupt change at critical micellar point. This property makes possible their utilization to critical micellar concentration, an important property of surfactants solution. We compared the obtained values of critical micellear concentration for sodium laurylsulfate and dodecylbezensulphonate with those obtained from conductivity measurements and we obtained good concordance. We studied also the influence of inorganic electrolytes to critical micellar concentration (CMC) values.

A series of all-solid-state electrodes sensible to the anionic surfactants were developed using silver pills coated with PVC membranes. We used cetyltrimethylammonium laurylsulfate (CTMA-LS) and tricapryl-methylammonium laurylsulfate (TCMA-LS) as electroactive matter (ionophore) and different plasticizers. The electrochemical properties of the electrodes were studied. The best electrochemical characteristics were obtained with TCMA-LS (dioctylsebaccate as plasticizer): nearnerstinan slope: 58,56 mV/pC; concentration range of linear response 10(-3)-2x10(-6) M.L-1 of laurylsulfate anion. The selected membrane-electrode can be applied as equivalence point indicator to the potentiometric titration of anionic surfactants and to the determination of anionic surfactants in environmental samples.

Influence of temperature and collector concentration on its adsorption rate on mineral surface was studied as regarding the 8-hydroxyquinoline/cerusite system. Theoretical equations as well as experimental data may be useful to estimate the adsorption rate and kinetics connected to the conditioning stage in mineral Rotation in order to optimise the selectivity and the recovery of the desired mineral.

This paper presents recent data on soil contamination with Pb, Cd, Cu and Zn at 5 and respectively 30 cm in depth and the pollution of surface waters in two protected areas in Maramures County. The measured values are presented in comparison with the limits defined by the Romanian legislation. In the case of Creasta Cocosului reservation, lead pollution reaches the intervention limit at 5 cm in depth and it exceeds the alert threshold at 30 cm. Lead contamination in Chiuzbaia reservation is also high at the 30 cm in depth, the Cd content exceeds the alert limit, while the values for Cu, Zn and Mn are over the normal admitted values. The high level of contamination with heavy metals of these areas is mainly related to local mining activities and non-ferrous metals concentrates processing.

Polyaluminium chloride is anew coagulation reagent recommended for water treatment. This paper presents a study regarding water treatment from the storage lake Stimtori - Firiza with this new coagulation reagent in comparison with the classic method currently applied. The classic method uses cake of alum (aluminium sulfate) and hydrated lime. In the case of atypical waters having low temperatures, low alkalinity and variable turbidity, the classic method has poor results. The main purpose of the experimental studies is to establish the adequate doses of coagulation reagent for obtaining drinking water according to present legislations.

In this work is presented a research on water treatment by using coagulation reagent such as Sachtoklar aluminium bases polychlorides and alkalinization reagent like sodium aluminate.The purpose of this research is to study the efficiency or inefficiency of these reagents to break up the colloidal systems and to reduce the turbidity of the treated water.To obtain the normal turbidity of water, it was established the relationship between the Sachtoklar aluminium bases polychlorides and the aluminate, as well as the best conditions of the coagulation process.Also it was studied the deposition time of formed floccules of the turbidities obtained at different doses of aluminum.

The paper presents studies regarding the water quality from the accumulation lake, characterised by higher turbidity in the studied period, and also the water treatment possibilities with pre hydrolysed coagulants and sodium aluminates, following the efficiency and inefficiency of these in the colloidal systems destabilization, in the purpose of a corresponding turbidity obtaining. To obtain the normal turbidity of the water, it was established the rapport between the aluminium bases poly chlorides and the aluminates and the best conditions of the coagulation process.

The paper presents the studies regarding the water treatment with new coagulation reagents (aluminium bases poly chloridess) and alkalisation, comparative with aluminium sulphate and calcium hydroxide, following the efficiency and inefficiency of those in the colloidal systems destabilisation and zeta potential reduction.