Session 14 - Efficient water resources management in Cr(VI) impacted water bodies

[CEST2019_00726] Evaluation of calcium polysulfide as a reducing agent for the restoration of a Cr(VI)-contaminated aquifer
by Mpouras T., Papassiopi N., Lagkouvardos K., Mystrioti C., Dermatas D.

This work aims at investigating the efficiency of applying calcium polysulfide (CPS) as a reducing agent for the decontamination of a heavily Cr(VI)-contaminated aquifer. Series of batch experiments were carried out in order to evaluate the reductive behavior of CPS towards the aqueous and solid phase. CPS was added in several stoichiometric excesses (2.0X, 2.6X, 4.6X and 6.5X) with respect to the Cr(VI) concentration measured in the contaminated groundwater. The effect of time on Cr(VI) reduction by CPS was tested performing short term batch experiments. In addition, the effect of CPS on other groundwater constituents, e.g. nitrates, and potential mobilization of soil elements, sensitive to redox changes (Mn, As, Co, etc.), were also evaluated. The experimental results showed that CPS can be effectively used for the remediation of the Cr(VI) contaminated aquifer without affecting significantly the soil properties.

Session: 14, Room: B, at Thu, 09/05/2019 - 16:15 to 16:30
Oral presentation in Efficient water resources management in Cr(VI) impacted water bodies
[CEST2019_00640] Harmonization of sampling and chemical analysis for the study of Cr(VI) water contamination in aquifers of eastern Mediterranean and Oman- the CrITERIA project experience
by Argyraki A., Kelepertzis E., Pyrgaki K., Botsou F., Megremi I., Dermatas D.

The CrITERIA project aims to deliver a harmonized data base, to assist water resource management organizations and water users on decision making when coping with water scarcity, climate extreme events and contaminated water. Contamination by Cr(VI) is used as an example of a specific water pressure problem that has to be tackled. Comparative, collaborative research using real situation data from case study areas in each of the participating countries was the base of our methodology. Such areas had already been identified in Greece and Italy and were further monitored, evaluated and compared to potentially affected water bodies in Cyprus, Turkey, Jordan and Oman, suspect for Cr(VI) contamination due to either natural or industrial sources within the same time frame. To enable comparison a common protocol for water sampling has been developed. This served as the base for monitoring water quantity and quality aspects in the case study areas and verify if Cr(VI) contamination levels exceed regulatory levels. The analytical QA/QC has been facilitated by analyzing a proportion of the samples from each case study area in an external accredited laboratory. The paper presents the developed sampling protocol and discusses the challenges during the harmonization of data from sampling and analysis.

Session: 14, Room: B, at Thu, 09/05/2019 - 16:00 to 16:15
Oral presentation in Efficient water resources management in Cr(VI) impacted water bodies
[CEST2019_00622] A DPSIR Approach To Selected Cr(VI) Impacted Groundwater Bodies Within Attica and Eastern Sterea Ellada River Basin Districts
by Pyrgakı K., Argyrakı A., Kelepertzis S., Botsou F. Megremi I., Karavoltsos S., Mpouras T., Dassenakis E., Hatzaki M., Dermatas D.

The holistic approach of the Driver-Pressure-State-Impact-Response (DPSIR) analytical framework in combination with Geographical Information Systems was applied to selected Cr(VI) impacted groundwater bodies. For the characterization of water-quality “state” 157 samples including field blanks were collected during the wet and dry seasons of 2017 and 2018 and several physicochemical parameters were determined. In Loutraki area, Cr(VI) in groundwater ranged from 12 to 62 μg/L while NO3 and Cl maximum values were 157mg/L and 218mg/L respectively. Very high concentrations of Cr(VI) (up to 430μg/L), NO3 (up to 245mg/L) and Cl (up to 1039mg/L) were measured in the Schinos alluvial aquifer. Additionally, Cr(VI) up to 131μg/L and NO3 up to 156mg/L were identified in the groundwater ofThiva agricultural area. In C. Evia, Cr(VI) was up to 96μg/L while NO3 and Cl concentrations were also high reaching 362mg/L and 793mg/L respectively. Finally, the highest Cr(VI) concentrations (up to 11.7 mg/L) were measured in Oinofyta area. The main identified pressures are: i) NO3 pollution due to intensive agriculture and urban waste disposal, ii) sea water intrusion due to overpumping and iii) Cr(VI) contamination due to both natural processes and industrial activities (clearly in the case of Oinofyta). In many cases, Cr(VI), NO3 and Cl are above the upper drinking water threshold values of the European Directive 98/83/EC.

Session: 14, Room: B, at Thu, 09/05/2019 - 15:45 to 16:00
Oral presentation in Efficient water resources management in Cr(VI) impacted water bodies
[CEST2019_00576] Preliminary study on Cr-rich groundwater treatment by membrane processes
by Fuoco I., Figoli A., Brozzo G., De Rosa R., Bloise A., Criscuoli A., Apollaro C.

The aim of this work is to treat chromium (Cr)-rich groundwaters through membrane processes as alternative to conventional methods. Commonly, the highest Cr (VI) concentrations into groundwater are detected in ophiolitic areas due to water-serpentinite interaction processes. In this work, the water sample treated comes from Bonassola serpentinitic aquifer (La Spezia, Liguria, Italy), in which a Cr(VI) concentration of 84 μg/l was detected. To lower down this value under the threshold established by law, NF/RO laboratory-scale system with membranes named DK (NF polyamide membrane, GE Osmonics) and AD (RO polyamide membrane, GE Osmonics) and CD (RO cellulose membrane, GE Osmonics) were used. The experiments were conducted at different operating pressures. Membrane process treatment was able to lower the Cr concentration within the threshold values, and rejections around 95% were registered for each used membrane. These preliminary results are quite promising for future developments on Cr removal from contaminated groundwaters.

Session: 14, Room: B, at Thu, 09/05/2019 - 16:33 to 16:36
Flash presentation in Efficient water resources management in Cr(VI) impacted water bodies
[CEST2019_00581] Synthesis of kaolin supported nZVI and evaluation for the removal of Cr(VI) and Ni from waste streams
by Toli A., Mystrioti C., Della A., Thymi S., Papassiopi N.

This study involved the synthesis of kaolin-supported nano zero valent iron (K-nZVI) and the evaluation of its performance for the removal of chromates and nickel from contaminated waters. K-nZVI was prepared by mixing a kaolin sample with a FeCl3 solution, followed by the addition of sodium borohydride for the reduction of Fe(III) to the zero valent state. The effectiveness of kaolin supported nZVI for Cr(VI) and Ni removal was evaluated by conducting batch experiments. The investigated parameters included the amount of K-nZVI per solution volume, the concentration of contaminants and the effect of pH. K-nZVI was found to be more efficient for the treatment of Cr(VI) contaminated waters than for the removal of Ni. Using 1 gram of K-nZVI per liter of solution, it was possible to reduce 20 mg/L of Cr(VI) to less than 5 mg/L within 3 hours. Starting with the same concentration of Ni, i.e.20 mg/L, the final concentration after 3 hours was aproximately 17 mg/L at pH 5.6, and dropped to 10 mg/L when the pH of the suspension was regulated to the value of 7.5. The results suggest the K-nZVI has a rather limited efficiency for Ni removal.

Session: 14, Room: B, at Thu, 09/05/2019 - 15:30 to 15:45
Oral presentation in Efficient water resources management in Cr(VI) impacted water bodies
[CEST2019_00594] Geogenic Cr(VI) in groundwater of the Pollino Massif (southern Apennines): occurrence and remediation.
by Paternoster M., Rizzo G., Sinisi R., Vilardi G., Di Palma L., Mongelli G.

In this study total Cr, Cr(VI), Ni, major and some trace elements were determined in groundwater of northern sector of the Pollino Massif. The investigated area is characterized by ophiolitic rocks consisting of metabasites and cataclastic and highly fractured serpentinites. Two different hydro-facies were observed, reflecting low-temperature water-rock interactions. The Mg-HCO3 hydrofacies was determined through the weathering of serpentinites, the Ca-HCO3 groundwater are due to the interaction with calcschist and metabasites. High Cr(VI) concentrations were detected, exceeding the maximum admissible concentrations by Italian regulation, due to the release of Cr(III) from ophiolitic rocks into water and its oxidation to the hexavalent state. Remediation tests were performed at different liquid/solid concentration, and the kinetic data were interpreted with a suitable mathematical model.

Session: 14, Room: B, at Thu, 09/05/2019 - 16:36 to 16:39
Flash presentation in Efficient water resources management in Cr(VI) impacted water bodies
[CEST2019_00538] Stakeholder Participation in Prioritization of Water Supply and Demand in Jordan
by Shammout M.W., Shatanawi M.

Stakeholder participation in prioritization of water supply and demand was developed to assist water resource entities and water users on decision making when coping with water scarcity, climate change and contaminated water in Zarqa River Basin, Jordan. The basin was selected for CrITERIA project to represent a case study of semi-arid area in the Mediterranean. The paper demonstrates a participatory approach of integrating stakeholders’ experience and their active involvement in water management. Issues related to prioritization of water demand were identified, and the opinions of stakeholder were ranked according to their role in securing supply and improving supply reliability. The most important issues were ranked according to number of opinions out of the total. Findings showed that water management issues was the major issue in the basin and represents 86% of the stakeholders opinions, followed by water supply as 82% to less extent by water demand as 77% and quality as 68%. Most of the stakeholders agreed that management issues are the major cause of water scarcity. Like expected, water problems in Jordan are 50% associated with poor management and 50% due to water scarcity.

Session: 14, Room: B, at Thu, 09/05/2019 - 15:15 to 15:30
Oral presentation in Efficient water resources management in Cr(VI) impacted water bodies
[CEST2019_00469] Occurrence and distribution of hexavalent chromium in ground and surface waters in Cyprus under the CrITERIA project
by Zissimos A., Christofi C., Christoforou I., Rigas M.

The origin and distribution of hexavalent chromium, Cr (VI) over four seasonal cycles was investigated through a conceptual model that included three aquifer systems in Cyprus. An extensive water sampling grid covered two sea water intruded coastal aquifers, namely the Kokkinochoria (A1) and Kiti-Pervolia (A2) aquifers and the Troodos massif (A3). Analytical results give a first insight to the presence of Cr (VI). Areas A1 and A2 exhibit high conductivity and nitrate concentrations (due to NPK fertilisers and seawater intrusion). The highest Cr (VI) value of 26 μg/l is observed in the Troodos area (A3) where Cr(VI) is detected in all water systems sampled (surface, ground and spring). Nonetheless, the highest mean value of 7 μg/l is exhibited in Kiti-Pervolia (A2). Stable isotope analyses show strong deuterium and Cr (VI) correlation with distinct differentiation between water systems. Troodos shows two distinct groups of meteoric and near meteoric waters whereas isotopically enriched water is shown to correspond to the Kiti and Kokkinochoria area.

Session: 14, Room: B, at Thu, 09/05/2019 - 16:30 to 16:33
Flash presentation in Efficient water resources management in Cr(VI) impacted water bodies
[CEST2019_00449] CrVI contaminated groundwater in the Mediterranean: Case study from Mersin, Turkey
by Hatipoglu-Bagci Z., Bayari C.S., Canakci A.

Increasing population, industrialization, agricultural and tourism activities in Mediterranean countries do not only increase the water demand but also led to deterioration of water quality. Water quality degradation is a common problem in all circum-Mediterranean countries and there is an increasing need for the development of a common approach in tackling water resources management problems. ERANETMED CrITERIA project aims to assist the water resources management organizations with an optimization tool that includes documentation and database for decision support. Greece, Italy, Turkey, Cyprus, Jordan and Omman are the partners of the project.
The project area in Turkey covers Mersin city and its surrounding. This region is located on the Mediterranean coast and consists of two main hydrogeological parts; the Coastal Aquifer and the Hillside Aquifer. The Coastal Aquifer is represented by a deltaic environment and The Hillside Aquifer is composed mainly of sedimentary and ophiolite rocks. Within the scope of the study, surface and groundwater samples were collected from the region in May 2017 and October-November 2017 and May-June 2018. About 50 sites were sampled in each period. It is determined that none of the samples has above the 50 µg/L limit of EU drinking water standard for total Cr, but some of the samples have CrVI contents above 10 µg/L. CrVI is regarded as a potential carcinogen.

Session: 14, Room: B, at Thu, 09/05/2019 - 15:00 to 15:15
Oral presentation in Efficient water resources management in Cr(VI) impacted water bodies