Ions Onto Diatomite from Aqueous Solution
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15th International Conference on Environmental Science and Technology Rhodes, Greece, 31 August to 2 September 2017 Spatiotemporal river water physicochemical profile and pollution hazard mapping in the wider area of Spercheios River catchment (Central Greece) Markogianni V. 1,*, Generalı K.2 And Dımıtrıou E.3 1,3 Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research, 46.7 km of Athens- Sounio Avenue, Anavissos 19013, Greece 2 Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, Botanikos, 75, Iera Odos, Athens 118 55, Greece *corresponding author: e-mail: [email protected] Abstract agricultural practices, chemical accidents, dam Human induced activities impose significant pollution construction, and natural processes like erosion, could each threats in river catchments worldwide. The Spercheios influence surface water quality. However, the degree that river outflows in the Maliakos Gulf and is located at each factor contributes to water quality is ambiguous Central Greece and protected under the Natura 2000 (Zhang et al., 2009a). Thus, determining the prevailing European network. The catchment land uses comprise pollution sources can help environmental managers to mainly intensive agricultural areas with significant make reasonable decisions as to the best actions for pollution pressures from fertilizers, small factories and improving water quality (Zhang et al., 2009b). Agricultural domestic wastewater. This study aims to identify and land-use is among the most important factors affecting the evaluate the impacts of land uses and human activities on quality of surface water and groundwater (Fohrer et al., the water quality of the river by spatially monitoring the 2001). Traditional methodologies to evaluating water fluctuations of physicochemical properties along the river. quality are based on the comparison of determined Physicochemical data from 10/2014 up to 07/2016 - parameter values with the existing guidelines but in many acquired from three automatic-telemetric monitoring cases, this does not readily give information on the status stations in Alamana (natural riverbed), Anthili (artificial of the source (Debels et al., 2005). One of the difficult riverbed) and Ipati (main river branch) - and chemical data tasks facing environmental managers is to convert complex from sampling stations adjacent to the telemetric, were data to information for better identifying the sources and used. Physicochemical data were statistically analysed in type of the pollution (Boyacioglu and Boyacioglu, 2008). hourly, seasonal and annual basis, chemical data were used This study focuses on the identification of the river basin’s to evaluate the water physicochemical status of the stations pollution sources through the pollution hazard map of the and subsequently all of them were related to the pollution wider area and the main objectives include: (1) the hazard/pressure map of the Spercheios catchment. The detection of significant pollution pressures and dominant results revealed the significant effects of human pressures biogeochemical mechanisms responsible for the spatial in the river water quality, especially downstream, and the variations in river water quality and (2) the identification outputs have been used to propose best practices for the of impacts from the pollution sources (natural and integrated management of the Spercheios river catchment. anthropogenic) on the water quality parameters and the chemical composition of the Spercheios River. Keywords: Spercheios river, physico-chemical properties, catchment, hazard map 2. Methodology 2.1. Study area 1. Introduction The Spercheios river is located in Phthiotis prefecture in Water resource management is a major challenge today, central Greece, is 85 Km long and the total area of its for socio-financial development, due to its association with drainage basin is 1,907.2 Km2 (Fig. 1). It is an area of downstream ecological impacts and water sources ecological significance included in the Natura 2000 (Thanapakpawin et al., 2006). network. A number of temporary streams discharge along During recent decades, concerns about the effects of land the north coast (Akoumianaki et al., 2013). The climate in use changes associated with desertification and agricultural the area of the Spercheios drainage basin belongs to the conversion have provoked social and political tensions sub-tropical Mediterranean zone, with warm and dry from local to national scales. Major interests focus on summer and mild and wet winter. The riparian forest in the results of landuse change for water supply and demand, at upper part of the delta occupies extended areas with width a local and regional level (Thanapakpawin et al., 2006). a ranging from few up to several hundred meters. The Human activities such as urbanization, industrial and CEST2017_00260 Figure 1. Spercheios River’s catchment, sampling and telemetric stations. 2 ο to be a pollution source (Andreo et al., 2006), was Spercheios river Delta occupies an area of 196 Km , at 23 calculated and classified into five hazard categories (from ο 30΄ longitude and 38 50΄ latitude. It extents about 4 Km very low to very high) according to Zwahlen (2004; see east of Anthili village and south-east of Lamia city and it is Table 1). the sixth in size Delta, in the shores of the Greek area (Efthimiou et al., 2014). Table 1: Hazard index values and the corresponding hazard levels according to Zwahlen (2004). 2.2 Water sampling, telemetric data and chemical determinations hazard index hazard index class hazard level Field sampling measurements of chemical parameters (nutrients) were conducted monthly or bimonthly in a 0-15 1 very low network of three (3) stations along Spercheios River (Fig. 15-30 2 low 1) from April 2014 to September 2015. Moreover, physicochemical data (water temperature, conductivity, 30-45 3 moderate salinity, pH, water level and dissolved oxygen 45-60 4 high concentration) from 10/2014 up to 07/2016 were acquired >60 5 very high from three automatic-telemetric monitoring stations in Alamana (natural riverbed), Anthili (artificial riverbed) and 3. Results Ipati (main river branch; Fig. 1), located precisely close to the sampling ones. Those data were statistically analysed 3.1 Statistical analysis of physicochemical telemetric data in hourly, seasonal and annual basis and subsequently examined for interrelationships. Concentrations of Correlation matrices among all available physicochemical nutrients (NO3−, NO2−, NH4+ and PO4 3−) were parameters of all the three telemetric stations indicated determined in the soluble fraction using an ion analyser various negative and positive correlations. The strongest Metrohm, the automatic analyzer Radiometer and the relationships were detected among electrical conductivity photometer Merck Nova 400. To classify the and salinity (R2 = 0.89), dissolved oxygen and salinity and physicochemical status of the river’s sites, the River dissolved oxygen and temperature, as it is expected. The Nutrient Classification System (Skoulikidis et al., 2006) correlation between pH and water level indicated low was applied for nutrients and the Norwegian system for positive correlations (R2 = 0.165 for Anthili, R2 = 0.143 for dissolved oxygen (Cardoso et al., 2001). Ipati). Water dissolved mineral substances, aerosols and dust from the air, received human wastes, and support of 2.3 Hazard mapping photosynthetic organisms are processes affecting pH. The For the identification and assessment of the pollution carbon dioxide content of water in rivers and streams is pressures in the Spercheios catchment, the CORINE 2006 less likely to change; mainly activities in the watershed map has been used according to the methodology applied may affect pH. Alamana station implied a negative at the COST Action 620 project, (Zwahlen, 2004), moderate relationship (-0.38) between water level and pH, focusing on the potential point and nonpoint pollution which partially can be attributed to photosynthesis by sources of the catchment tributaries that discharge into aquatic plants removing carbon dioxide from the water, a Maliakos Gulf. For each recorded land use in the study fact that can significantly increase pH. Water level was area, a weighted pollution factor (hazard index), describing also positively correlated to dissolved oxygen the intensity and possibility of each potential land use type concentration, since the decrease of the water level and the CEST2017_00260 Figure 2. Box plots presenting the annual distribution of (a) electrical conductivity values (b) pH values and frequency charts presenting aggregated data of (c) electrical conductivity values and (d) dissolved oxygen concentrations of all telemetric stations (green line: mean value, red line: median value). river’s flow rate, decreases the mixture of water with air, be processed due to technical problems of the sensor (Fig. resulting in further DO decrease. Concerning the annual 2d). fluctuation of electrical conductivity values (Fig. 2a), 75% 3.2 River water physicochemical status monitoring of the Alamana station’s measurements on 2014 were close to 550 μS/cm, while on 2015 and 2016 the values ranged According to the physicochemical telemetric data and the around 200 μS/cm. In Anthili station in years 2014 and nutrient analysis, the physicochemical status of the 2015, values between the 50th and the 75th percentile were Spercheios River indicates a degradation from the pretty