SORAS Description

Description
Solar oxidation and removal of arsenic (SORAS) is a simple method that uses irradiation of water with sunlight in PET - or other UV - A transparent bottles to reduce arsenic levels in drinking water. Experiments in Bangladesh show that the process on average can reduce arsenic content of water to about one - third.

Development
Swiss Federal Institute for Env. Science and Technology
Swiss Agency for Development and Cooperation

Benefits & Drawbacks

Benefits
  • Simple
  • Scientifically proven
  • Excellent microbial removal
  • Bottles widely available
  • Water is already contained in a safe storage vessel
Drawbacks
  • The arsenic removal efficiency is limited to approx. 50 - 70 % and hence, raw water up to 100 - 150 µg/L can be treated with this low-cost method.
Comments
  • Arsenic affected people are desperately waiting for water treatment options which have to be developed and promoted by the different actors of the Bangladesh Arsenic Mitigation Water Supply Project (BAMWSP). SORAS is such an option, at least it is a useful interim measure until better options are available. Faced with the choice between drinking water that contains 150 and more µg/L of poisonous arsenic, or after treatment by SORAS, water that contains half or a quarter of that amount, who would not opt for the latter? Furthermore, SORAS also removes the iron and improves the taste of the water to which people attribute a high interest.

Costs

The costs associated with SORAS are minimal because the only materials needed are plastic bottles. Solar reflectors and cookers can also be made cheaply using cardboard and aluminum foil.

Resources

References & Links

Contact Information