ITN-BUET has conducted a number of researches on arsenic issue. In continuation to that, a research on “Assessment of the Performance of Modified AIRU under Different Hydro-Geological Conditions” was conducted by ITN-BUET. This publication is the outcome of that initiative. Promotion of technologies for removing arsenic is one of the important policies of the government for providing safe drinking water. The focus of the present study was on removal of both arsenic and iron from groundwater by using AIRU (Gender. It is expected that this publication of ITN-BUET will be an important reference for research and development activities of the government, non-government organizations, development partners and other agencies working in the WSS sector especially on arsenic issue. In addition, this publication will also be useful to the scientists, researchers and sector professionals to undertake further researches to enrich the knowledge base in this particular area.