Horizontally embedded Fe(0) electrocoagulation to enhance As(III) removal in biologically active rapid sand filters for drinking water treatment

The presence of high levels of arsenic in groundwater, an otherwise preferred drinking water source, urges the need for innovative and highly efficient (in terms of chemical use and energy consumption) technologies to remove arsenic during drinking water treatment. This research focussed on embedding iron electrocoagulation (Fe-EC) within a...

Iron Removal in Low Salinity Water: A case study of brackish water reverse osmosis permeate

A reverse osmosis (RO) membrane followed by a packed tower aerator and rapid sand filter are used by an agricultural company in Emmen to treat brackish groundwater to supply water for growing crops and cleaning purposes. The iron removal by the treatment plant is sufficient most of the time throughout the year. However, the farmer periodically ...

Genomic profiles and removal mechanisms explain the observed stratification of Fe²⁺, NH₄⁺ and Mn²⁺ removal in rapid sand filters

Groundwater is an excellent source for the production of drinking water due to its low concentration of microorganisms and contaminants. The main contaminants present in groundwater are iron, ammonium and manganese, which are sequentially removed in rapid sand filters by a combination of biological and chemical processes. Currently, limited...

Biological As oxidation during start-up of rapid sand filters

Removing iron under anoxic conditions

Aeration and rapid sand filtration are common practice for the treatment of iron, manganese and ammonium containing ground water for more than a century. Nevertheless, this process has not become obsolete. On the contrary, this thesis assumes that enhanced rapid sand filters remain standard treatment technology in the 21st-century. Iron can be...

Monitoring of rapid sand filters using an acoustic imaging technique

A novel instrument is developed to acoustically image sand filters used for water treatment and monitor their performance. The instrument consists of an omnidirectional transmitter that generates a chirp with a frequency range between 10 and 110 kHz, and an array of hydrophones. The instrument was extensively tested in a lab before being...