Algae and particle removal in direct filtration of Biesbosch water

Abstract not availableApplied Science

Groundwater Quality of Drinking Water Wells in the West Bank, Palestine

Groundwater, the main drinking water source in the West Bank, is highly vulnerable to pollution given the karstic nature of the aquifer. This study was aimed at screening the quality of groundwater used for water supply, in terms of physicochemical and microbiological properties, and heavy metals concentrations. Attention was given to groundwater chemistry, using piper and Durov diagrams, to assess potent impact of pollution on groundwater. Twenty-nine groundwater samples from selected wells, representing the different groundwater fields in the West Bank, were collected and analyzed. The results revealed that the concentration of the ions and parameters affecting the aesthetic and health related water quality, such as Cl−, Na+, NH4+, TDS, and NO3−, and selected (semi) metals, including Cr, Cu, Fe, Mn, Pb, Cd, and As, are within the limits recommended for drinking water. The dominant cations and anions were in the order of Ca2+ > Na+ > Mg2+ > K+ > NH4+ and HCO3− > Cl− > NO3− > SO42−, respectively. The total average groundwater hardness is approximately 2.1 mmol/L and can be attributed to calcium (approximately 60%) and magnesium. The major ground water types in the West Bank were fresh water (Ca-Mg-HCO3), fresh water mixed with another water type (Ca-Mg-Na-HCO3 or Ca-Mg-HCO3-Cl), and extreme water type (Na-Ca-Mg-HCO3-Cl or Na-Ca-HCO3-Cl) showing high TDS, Cl− and Na+. Signs of pollution, namely elevated levels of nitrate and ammonium, were, however, observed even in some deep wells (>600 m), despite the thick cover of soil, tapping the Lower Ceneomanian confined aquifer

Direct filtration of Biesbosch water and Algae and water treatment in the Netherlands: 3rd Direct Filtration Seminar

This presentation summarises basic information on direct filtration, and demonstrates the main research findings, related to the performance of simple in-line direct filtration. The results reported are part of a comprehensive ongoing research programm "Direct filtration of Biesbosch water" undertaken jointly by Delft University of Technology and International Institute for Infrastructural, Hydraulic and Environmental Engineering (IHE Delft). The main research goal of the study is to assess the applicability of direct filtration to water from Biesbosch reservoirs. The key issue addressed in this study is coagulation of algae and other particles and their subsequent removal in rapid sand filters.Water ManagementCivil Engineering and Geoscience

Reduction of ripening time of full-scale manganese removal filters with manganese oxide-coated media

Effective manganese removal by conventional aeration-filtration with virgin filter media requires a long ripening time. The aim of this study was to assess the potential of manganese oxide-coated media to shorten the ripening time of filters with virgin media, under practical conditions. A full scale filter filled with virgin sand and a full scale filter filled with anthracite/sand were operated at two groundwater treatment plants, in parallel with (full scale) test filters, with an additional layer of Manganese Oxide-Coated Sand (MOCS) or Manganese Oxide-Coated Anthracite (MOCA). Significantly different ripening times were observed to achieve an effective manganese removal: 55 days for a filter with virgin sand and 16 days for a filter with virgin anthracite/sand, respectively. The observed differences could be attributed to different feed water quality, different iron loading, and backwashing intensity and frequency. In batch experiments fresh MOCA and MOCS showed good manganese adsorptive properties. Addition of a shallow layer of fresh MOCA in test filters eliminated the ripening time, while a layer of aged MOCS did not significantly shorten the ripening period. The poor performance of the aged MOCS was likely caused by changed properties of aged and dried MOCS, that had lost its adsorption capacity, the auto-catalytic activity and the biological activity.Water ManagementCivil Engineering and Geoscience