Development of affordable adsorbent systems for arsenic and fluoride removal in the drinking water sources in Tanzania (DAFWAT)
In this study, investigation and optimisation of the use of low-cost affordable adsorbents to remove fluoride and Arsenic from water will be perfected at laboratory scale, and a pilot water defluoridation plant will be constructed and tested.
Project name and -number: Development of affordable adsorbent systems for arsenic and fluoride removal in the drinking water sources in Tanzania (DAFWAT), Sida Contribution no.: 51170071
Project leader: Prosun Bhattacharya, SEED, and Felix Mtalo, University of Dar es Salam (UDSM), Tanzania
Participating universities/companies/other organisations: KTH Royal Institute of Technology
Project period: 2015-2020
Financing: Swedish International Development Cooperation Agency (Sida)
There is a serious problem of elevated concentration of Arsenic and Fluoride containing waters in parts of the Tanzanian Rift valley, particularly in the Northern regions. The elevated concentration of these elements has posed a serious medical problem for dental, skeletal and skin cancer. About 90 per cent of the population living along the Great Rift Valley are affected by dental fluorosis at some point. Fluoride issues have been having a lower priority and less action has been taken to overcome the problem. In some communities there is no reliable source of low-fluoride water and people may not realise the effects it has on their daily lives.
Current defluoridation technology employed in northern Tanzania is based on household and community scale units. The units use bone char for sorption of fluoride. While this technology reduces the fluoride level, it cannot produce water that complies with WHO guideline values especially due to colouration and in some cases smell. There is also the problem of preparation of the bones, collection of sustainable quantities and some religious beliefs.
In this study, investigation and optimisation of the use of low-cost affordable adsorbents to remove fluoride and Arsenic from water will be perfected at laboratory scale, and a pilot water defluoridation plant will be constructed and tested at one of the places with excess fluoride under the Arusha Urban Water Supply and Sewerage Authority (AUWSA). This will also involve a pilot plant for preparation (crushing, sieving and calcination) of adsorbents from locally available adsorbents rawmaterials (gypsum, bauxite and magnesite). The other impurities such as colour, organic matter and trace elements will be removed by appyling the membrane technology.