Abstract:
Ground water is a major source of safe water for drinking and
other domestic purposes for the rural I urban population of
Bangladesh which may have iron content in excess of 5 mg/L.
This study is an experimental investigation to observe the
effect of different factors in iron removal and also to develop
simple and cost effective iron removal method.
Relevant literature on chemistry of iron content water and unit
processes of iron removal have been reviewed, and water use
pattern and distribution of iron in ground water have also been
focused.
Investigations were made at laboratory condition on artificial
iron content water and natural ground water collected from
tubewells of iron prone areas to find out effect of different unit
processes and other related factors on iron removal.
Experimental results shows that filtration is an effective mode
of iron removal. However, considering the frequent cleaning
of the filter bed and low yield, in this study emphasis have
been given on sedimentation, for effective and efficient iron
removal. As an aid in improving settling characteristics of the
precipitated iron, coagulation is observed to be an important
tool.
Aeration, coagulation and 30 min sedimentation can reduce
iron concentration to allowable limit of 1 mg/L. However, the analysis also shows that iron removal increases with an
increase in anion concentration. More pronounced effect is
observed when the added anion is common to the anion
already in solution, due to common ion effect. Alum used as
coagulant is observed to be more effective than lime in iron
removal. Whereas, the coagulant cost involved using alum as
coagulant is 191.7% higher than lime.
