Environmental Engineering Reference
In-Depth Information
17.7.7.1 Composite-Type Adsorbent-Based Domestic Deluoridation
Unit “NEERMAL” of the CSIR-NEERI
A domestic deluoridation drinking water unit named “NEERMAL” has been designed in
which the developed material NEERMAL was used as deluoridation media (Figure 17.6).
A pair of cartridges containing NEERMAL mixed with sand has been retroitted in a com-
mercial ilter. NEERMAL material can be applied for deluoridation of wastewater also.
NEERMAL, a composite material based on metal oxide and carbon, nitrogen, and other
elements/functional groups for removal of luoride from water and wastewater has been
developed. The composite-based adsorbent shows luoride uptake capacity in the range of
5-14 mg/g under different conditions, with good selectivity and a wide pH range for luo-
ride uptake. The ield trials on the prototype units are proposed for detailed evaluation
with respect to its feasibility. The unit is especially designed for domestic applications in
India and other developing countries. It works on gravity low with no electricity require-
ment and gives luoride levels below the prescribed limit of 1 mg/g in treated water.
17.7.7.2 Household Treatment Methods for Fluoride
Removal in Rural Areas by CSIR-NEERI
The CSIR-NEERI in collaboration with UNICEF (Bhopal unit) has carried out user percep-
tion studies for assessing the acceptability of various domestic deluoridation techniques
for rural applications. Some of these techniques are described here.
17. 7. 7. 2 .1 L o o s e S o rb e nt
In this method, a predeined dose of adsorbent is added to approximately 1 L of water and
stirred continuously by using a stick for about 10-15 min (Figure 17.7). Stirring ensures
a good contact between adsorbent and luoride-contaminated water. After stirring, the
adsorbent was separated by iltering the treated water through a piece of cotton cloth.
FIGURE 17.6
Domestic deluoridation unit prototype based on composite-type adsorbent (CSIR-NEERI, India).
