In general, groundwater is a preferred source of drinking water because of its convenient availability and its constant and good quality. However this source is vulnerable to contamination by several substances. Acceptable quality limits relative to micropollutant contents in drinking water are becoming increasingly lower and efficient elimination treatment processes are being implemented in order to meet these requirements. Metals contaminants at low concentration are difficult to remove from water. Chemical precipitation and other methods become inefficient when contaminants are present in trace concentrations and the process of adsorption is one of the few alternatives available for such situations. This book describes the adsorption method in the removal of selected heavy metals present as cations (Cd2+, Cu2+ and Pb2+) or oxyanions (Cr(VI) and As(V)) using iron oxide coated sand (IOCS) and granular ferric hydroxide (GFH). The effects of pH, natural organic matter (fulvic acid (FA)) and interfering ions (PO43-, Ca2+) on the adsorption efficiency were also assessed. The sorption reactions that take place at the surface of the adsorbent were also described through the surface complexation modelling for Cd2+, Cu2+ and Pb2+ adsorption. Batch adsorption tests and rapid small scale column tests (RSST) were used as laboratory methods.
Table of Contents
2: Assessment of groundwater quality in Eastern Rwanda; case study of Nyagatare District
3: Effect of calcium on adsorptive removal of As(III) and As(V) by iron oxide based adsorbents
4: Effect of phosphate on chromium and cadmium removal from groundwater by iron oxide coated sand (IOCS) and granular ferric hydroxide (GFH)
5: Effect of calcium on adsorptive removal of copper and cadmium by Iron oxide coated sand and granular ferric hydroxide
6: Effect of Fulvic Acid on Adsorptive Removal of Cr(VI) and As(V) from Groundwater by Iron Oxide Based Adsorbents
7: Adsorption and surface complexation modelling of trace metal sorption onto iron oxide coated sand
8: Summary and conclusions
Mrs. Valentine Uwamariya was born at Shangi Sector in Nyamasheke District on the 14th May 1971. She went to Groupe scolaire Sainte Famille Nyamasheke for secondary education and later joined the National University of Rwanda. She graduated with the degree of Bsc in Organic Chemistry in 1999 with distinction. From June 2000, she has been working as assistant lecturer at the same university, in the Department of Chemistry. In 2003, she joined the University of Witwatersrand in South Africa where she obtained a Master of Science in Electrochemistry in 2005 with distinction. In the same year she has been promoted to the grade of a lecturer. In 2007, she was awarded a scholarship by the Netherlands Government to study a PhD at UNESCO-IHE, Institute for water Education, under sandwich construction program. Her area of interest is analytical chemistry applied to the environment.