Groundwater and surface water in the Edwards Plateau region exhibits spatial variability arising from mineral differences in aquifers and mixing of groundwaters with diverse flow paths and ages. Integration of basic hydrochemical and isotope data (⁸⁷Sr/⁸⁶Sr, [delta]¹⁸O, [delta]D, ¹⁴C, ³H) document that groundwaters in the Lower Cretaceous Edwards-Trinity (Plateau) aquifer system reflect intermixing of modern and Pleistocene recharge. Pleistocene recharge occurred under cooler paleo-climatic conditions, based on [delta]¹⁸O variance of 4.59%, and flow traversed sub-cropping Permian evaporite and Triassic strata under hydraulic conditions that promoted upward flow into the Plateau system. Recharge areas may have been in topographically elevated areas in New Mexico that no longer are connected with the Plateau. Present distribution of groundwaters with higher SO₄/Cl values occurring beneath topographic divides on the Plateau suggests that modern recharge occurs preferentially in losing-stream networks and is inhibited on divides by low-permeability soils. Relationships between ¹⁴C, tritium, [delta]¹³C, and Mg/Ca values confirm that effectively younger groundwaters occur beneath the upper parts of drainage networks, but down slope of divides. Thus, groundwater-age and hydrochemical data suggest that recharge preferentially occurs in the upper parts of drainage networks. Correlations between groundwater relative age and Mg/Ca enable estimation of the proportion of modern recharge at specific well locations based on Mg/Ca values and enables estimating local absolute recharge rates from regional-scale recharge estimates obtained from regional flow models. The Upper Colorado River bounds the northern and northeastern margin of the Plateau system and shows systematic chemical evolution along its flow path, including decreasing salinity and increasing SO₄/Cl values. The stream can be conceptually divided into three segments that each reflect groundwater inputs from five hydrochemically distinct intervals: 1) deep Permian and Pennsylvanian reservoirs similar to those that produce hydrocarbons in the region; 2) Upper Permian halite (Salado Formation); 3) the Triassic siliciclastic aquifer (Dockum Group); 4) the sulfate-evaporite-bearing Permian system (Ochoan, Guadalupian, and Leonardian Series); and 5) the Plateau aquifer system. Conservative mixing models suggest that any aquifer that the river is traversing at a specific location contributes a distinct hydrochemical signature, but the dominant contribution is from the Plateau system. / text

Οι περιβαλλοντικές επιπτώσεις από τη λατόμευση και επεξεργασία γύψου στις μονάδες παραγωγής γυψοσανίδων,αφορούν το έδαφος, την ατμόσφαιρα, αλλά και τους επιφανειακούς υδάτινους σχηματισμούς (λιμνοθάλασσα, λίμνες). Στην παρούσα εργασία γίνεται προσπάθεια να ποσοτικοποιηθούν οι παραγώμενοι ρύποι και να περιγραφεί η αλληλεπίδραση των ρύπων με την γεώσφαιρα, υδρόσφαιρα, ατμόσφαιρα και βιόσφαιρα. / The environmental impacts of the gypsum extraction and processing that produces plaster board, inside the gypsum plants, not only affects the soil and the atmosphere,but also the surface water reservoir. With this present task I try to give emphasis to the quantification of the derivative pollutants and a description of the interaction of the pollutants as far as it concerns the geosphere, hydrosphere, atmosphere and biosphere.

Combining geochemical data with physical data produces a powerful method for understanding sources and fluxes of waters to river systems. This study highlights this for river systems in regions of complex hydrogeology, shown here through the identification and quantification of base-flow sources to the Verde River and its tributaries within the middle Verde River watershed. Specifically, geochemical tracers (major solutes, stable and radioactive isotopes) characterize the principal aquifers (C, Redwall-Muav, and Verde Formation) and provide a conceptual understanding of the hydrologic connection between them. For the surface-water system, PCA is utilized to identify potential base-flow sources to the Verde River on a several-kilometer scale. Solute mixing diagrams then provide relative inputs of these sources, and when combined with stream discharge, allow for quantification of water sources. The results of this study provide an improved conceptual model that reveals the complexity of groundwater-surface water exchanges in this river basin.

The occurrence of chemical contaminants in the environment is one of the key issues the world isfacing today. Special effort has been put on the screening of endocrine disrupting compounds(EDCs), substances that have been shown to have adverse effects on the endocrine system. EDCs are mainly found in pharmaceuticals and personal care products (PPCPs), but also other products covering almost all categories of our daily life. EDCs can be both organic, such as the persistent organic pollutants (POPs), and inorganic, e.g. heavy metals. Today, all kinds of EDCs are currently being investigated on a large scale. Two EDC sub-categories that have gained increased public attention during the last years are organic flame retardants (FRs) and per- and polyfluoroalkylated substances (PFASs). Both categories have shown to be bioaccumulating, persistent and toxic, which has led to banning of several substances in both categories. However, as both FRs and PFASs are considered to be emerging POPs, their fate and behaviour in the environment are still in great need of research. FRs and PFASs often end up in surface waters due to their disinclination of getting removed in waste water treatment plants (WWTPs) and their persistence. Thus, the objective of this project was to provide a snapshot of the current situation of FRs and PFASs in Swedish rivers, including both smaller streams and bigger rivers. Grab water samples were taken at 25 sites for FRs and 44 for PFASs in rivers all over Sweden. The results showed that sparsely populated areas such as the northern part of Sweden generally showed lower concentrations of PFASs in the water than the southern part did. The summarised concentrations of FRs ranged from 37 ng L-1 to 4.6 μg L-1, and from 0.59 ng L-1 to 59 ng L-1 for the detected PFASs, which was in good comparison to previous studies carried out on surface water in Europe. The percentile composition, the so-called fingerprint, showed significant differences between the southern part and the northern part for both FRs and PFASs, but also great similarities between some of the rivers with the highest measured PFASs concentrations. The highest loads of both FRs and PFASs were detected in Delångersån, which is one of the smaller rivers screened and likely to be affected by a nearby industrial point source. The European environmental quality standard of 0.65 ng L-1 of perfluorooctane sulfonic acid (PFOS) was exceeded in 12 of all 44 sampled rivers.

Vandenų apsauga yra viena iš svarbiausių aplinkosaugos sričių. Europos Sąjungos direktyvos griežtai reglamentuoja išleidžiamų į paviršinius vandenis miestų nuotekų kokybę. Ne mažiau kaip 80 procentų išleidžiamų nuotekų neturi viršyti didžiausios leidžiamos koncentracijos. Darbo tikslas ištirti nuotekų valyklų Raseinių rajono savivaldybėje darbo efektyvumą ir numatyti priemones jų darbui pagerinti. Darbe analizuojama Raseinių rajono (Raseinių, Ariogalos, Kaulakių gyvenviečių) nuotekų valyklų darbo efektyvumas. Analizei naudoti 2005-2007 metais atliktų tyrimų duomenys. Duomenų analizė parodė, kad visoms valykloms reikalinga rekonstrukcija, visose gyvenvietėse reikia didinti prie centrinės nuotekų šalinimo sistemos prisijungusių gyventojų skaičių. / The protection of water is one of the most important spheres in the environment control. The quality of cities‘ sewage, that is drained to surface water, is strictly regulated by the directives of European Union. Not less than 80 per cent of drained sewage must not exceed the maximum allowable concentration. The purpose of this research is to analyse the effectiveness of sewage works in Raseiniai district and to provide the plant improvement scheme. In the article there is discussed the effectiveness of sewage works in Raseiniai district (Raseiniai, Ariogala, Kaulakiai). The data of 2007 is used in the analysis. The results show that the reconstruction is necessary for all the sewage works. Moreover, in all the places of residence it is a must to increase the number of residents who are linked to the central sewage removal system.

Two wild blueberry fields were selected to evaluate the impact of variable rate (VR) fertilization on crop productivity, surface and subsurface water quality. Management zones were delineated based on slope variability, and different fertilizer rates were applied according to prescription maps. Runoff collectors were place in the fields to measure the nutrient losses in surface runoff, while lysimeters were installed to evaluate the impact of VR fertilization (VRF) on subsurface water quality. The VR treatment significantly decreased phosphorus and nitrogen loadings in surface runoff as compared to uniform treatment. The concentrations of nutrients in subsurface water samples were also significantly lower for VR treatment as compared to uniform treatment. The excessive nutrients enhanced vegetative growth in low lying areas of uniform fertilization, while berry yield was less. Based on these results, it can be concluded that VRF in wild blueberry fields improved the crop productivity and potential environmental impacts. / This study was conducted to evaluate the impact of variable rate fertilization on crop productivity and surface and subsurface water quality in wild blueberry fields. Result illustrated that variable rate fertilization significantly reduce the nutrients loading in surface and subsurface water, and improved blueberry yield.

Research has shown biological filtration can be a successful treatment for manganese (Mn) removal from groundwater and surface water. In this study, bench-scale direct biofiltration was used to remove Mn and dissolved organic carbon (DOC) from a pH 6 surface water source in Halifax, Canada. The removal of Mn in pH 6 surface water was significantly (? = 0.05) removed with 200-300 µg/L phosphorus (P), and 500 µg/L hydrogen peroxide (H2O2). DOC removal was significantly (? = 0.05) improved with granular activated carbon (GAC) media, P enhancement at 200-300 µg/L, and H2O2 enhancement at 500 µg/L. Mn was likely removed by biological oxidation and physical adsorption to biogenic Mn and iron (Fe) oxides. These results show direct biofiltration of surface water at pH 6 can remove Mn below the 50 µg/L aesthetic guideline from a Mn loading of over 1 mg/L. Further research is required to verify the microbial mechanism.

Groundwater is an important source of baseflow. Baseflow supports minimum flows and living area through dry periods, and moderates surface water temperature. The reductions in baseflow after urbanization can cause degradation of the stream ecosystem. The purpose of this study was to investigate the groundwater-surface water interaction and thermal regime of Clythe Creek, Guelph to illustrate the importance of groundwater/streamflow interaction in determining the health of a stream ecosystem. Piezometers were used to quantify vertical and lateral groundwater flow direction, and surface water temperature measurements were used to characterize and quantify the thermal regime. Groundwater-surface water interaction varied both temporally and spatially between the two geomorphic units. Average summer surface water temperatures were consistently cooler in the downstream portion of the study reach. The importance of groundwater-surface water interactions in supporting stream ecosystems was concluded from this study, and restoration strategies to address threats from urbanization were made. / Ontario Research Fund (ORF)

Natural organic matter (NOM) is present in all surface waters as a result of decaying vegetation, biological activity, and organic soil. Alternative NOM removal processes such as anion exchange resins (AERs) have shown NOM removals typically ranging between 50 to 90%, with up to 99% removal achieved in some cases. The first portion of this study evaluated the performance of two AERs; a conventional Type 1 AER and magnetic ion exchange resin (i.e. MIEX®) for NOM removal from surface water quantified by UV254, dissolved organic carbon (DOC), and specific UV absorbance (SUVA). Samples were also characterized for chloride, sulphate, and chloride-to-sulphate mass ratio (CSMR) to provide additional information on water quality characteristics of AER treated waters. Overall, the results showed that both AERS were effective for removing NOM. However, the MIEX® resin provided greater removal of NOM with shorter contact times compared to the conventional resin investigated. Water treated with MIEX® resin showed significantly higher chloride and lower sulphate concentrations than the conventional AER. Higher CSMR values were found with MIEX® treated water compared to conventional AER system, although both resins showed CSMR much greater than 0.5, which can increase galvanic corrosion effects with lead. Bench-scale jar tests were conducted to investigate the impact of temperature on the efficacy of three NOM removal treatment technologies; enhanced coagulation with alum, MIEX® and a combined MIEX® treatment followed by coagulation with a low dose of alum. Higher settled water turbidity was observed during cold water operating conditions for all three processes. At cold-water operating conditions, DOC removal was reduced with combined MIEX® -Alum treatment, and UV254 removal was impacted for both MIEX® and MIEX® -Alum processes. The combined MIEX®-Alum process was found to provide the lowest THMFP and HAAFP at both temperatures to concentrations lower than current regulatory maximum acceptable concentration (MAC) guidelines in Canada. Surface charge analysis experiments were performed at bench-scale using synthetic water containing humic acid to determine the relationship between NOM and the charge of AER-treated waters. Further bench and pilot-scale studies were performed to investigate the use of surface charge measurements to monitor and optimize NOM removal during treatment with AER systems. Strong correlations were observed between UV254 and respective charge measurements (i.e. ZP, SC) of AER-treated synthetic and raw waters. The results of this research has shown that it is possible to use charge to optimize the MIEX® process for NOM removal. Additionally, it was found that SC measurements could be used as an operational tool for AER processes, where deviations in SC from optimum treatment would indicate the requirement for fresh resin addition or resin regeneration.

In order to improve the water situation in rural areas of Bangladesh, a research group at the University of Dhaka has been developing low cost domestic methods to remove pathogens from surface water through pasteurisation using free solar energy. Pasteurisation is a process in which water is heated to approximately 60 °C and maintained for about 30 minutes to destroy pathogens. In these methods, the water is also exposed to UV-light from the sunshine, which causes destruction of diarrhoeal pathogens at temperatures somewhat lower than required in normal pasteurisation. However, despite many advantages these devices need to be installed for each time of use. Recently, a semi-permanent device has been developed which is expected to be more user friendly. The objective of this Master thesis has been to study and optimize the low cost semi-permanent device that can deliver safe drinking water to people in rural areas. Two test devices were constructed to determine the most effective treatment e.g. temperature, time, solar radiation, user-friendliness and cost. To replicate the results from the solar heating tests a model, based on the solar radiation and convective heat loss from the device, was used. The model was also able to determine the time duration at a certain solar radiation level to estimate when the water is safe to drink. The results revealed that the performance of the device depends on thickness of the insulation and thickness of the air gap. This is because the most important factors to achieve safe drinking water are solar radiation and time. The modelling indicated that the measured water temperature corresponds well with the calculated water temperature and also showed that the lowest required solar radiation is 390 W/m2 to reach drinking water criteria, at an air temperature of 25 °C. A study of microbiology showed that the semi-permanent low cost device could purify surface water to a safe level.