This document presents information on removing boron from water using reverse osmosis (RO). It discusses the health risks of boron in drinking water and various boron removal methods. It outlines the RO process, factors that affect it like pH, pressure and temperature. Experimental results show boron rejection increased with higher pH and pressure. The conclusion is that RO can effectively remove boron when optimizing operating conditions.

1. Presented by:-
Akhilesh Kumar Kushwaha
M.Tech – Chemical Engineering
Malaviya National Institute of Technology Jaipur
Removal of Boron from Water
using Reverse Osmosis
National Conference on Water Quality
Management
(NCWQM) – December20-22 , 2012

2. Contents
 Introduction
 Health Risks and Ecological implications
 Methods of removal of boron
 Reverse osmosis
 Factors affecting RO
 Advantages and disadvantages of RO
 Boron analysis
 Experimental setup
 Results and discussions
 Conclusions
 References

3. Introduction
 Boron is a naturally occurring element found in rock
and soil
 Surface and ground waters as well as waste waters at a
concentration level of 5-100 mg/liter
 In water, boron exists in the form of boric acid
 Recent rapid growth in water desalination by RO
technology, the issue of boron removal has come to the
light
 Natural sources and Anthropogenic sources

4. Health and Ecological Implications
 WHO permissible limit for drinking water (0.5mg/l)
 Borism, teratogenic effects, nausea etc.
 Boron is an essential nutrient for plants
 Chlorosis (discoloring of leaves) & necrosis
 Plants can occasionally be stressed by boron toxicity
and salinity simultaneously

5. Methods of boron removal
 Reverse osmosis
 Ion exchange
 Adsorption
 Coagulation and precipitation

6. Reverse Osmosis (RO)
 In reverse osmosis, two solutions are separated by
a semi-permeable membrane, pressure is applied
to reverse the natural flow of the water. This forces,
the water to move from the more concentrated
solution to the less concentrated
 Spiral wound membrane element

7. RO…
Solution diffusion model:
 The RO membrane has a homogeneous, nonporous
surface layer
 Both the solute and solvent dissolve in this layer and
then each diffuses across
 Diffusion is due to its own chemical potential gradient
across the membrane
 Gradients are the result of concentration and pressure
differences across the membrane
 Transport across the membrane:
Jw = A(∆P-∆ᴫ )

8. RO...
Different stages in RO treatment process:
 Pretreatment
 Pressurization
 Separation
 Post treatment

9. Factors affecting RO
 pH
 Pressure
 Temperature
 Salt concentration
 Effect of recovery

10. Advantages & disadvantages
Advantages
 Can treat low to high TDS seawater
 Low maintenance
 Green technology
 Single step separation
 Installation cost low
Disadvantages
 Membrane change
 High membrane cost
 Parameters should not exceed their limits
 Pretreatment required

11. Boron Analysis Method
Curcumine Spectrophotometer Method:
 Boric acid on reaction with curcumine
(diferuolylmethane – C21H20O6) in acidic solution
results in a red color boron – chelate complex called
Rosocyanine.
 Absorbance of this solution was taken at 540 nm.

12. Experimental Setup

13. Result and Discussion
The effect of pH on % boron rejection:
Conc. = 20 ppm & P = 5 bar at Temp = 23 C
Fig(1): Variation of boron rejection with pH
0
2
4
6
8
10
12
0 20 40 60 80 100 120
pH
% removal

14. Results Contd…
Variation of % boron rejection with applied pressure:
Temp = 23 C , Conc. = 20 ppm & pH=10
Fig(2): effect of pressure on % boron removal
0
20
40
60
80
100
120
0 20 40 60 80 100 120 140
%Bronrejection
Time(min)
2 bar
5 bar

15. Results contd...
Variation of permeate boron conc. with time
Conc. = 20 ppm & P = 5 bar at Temp = 23 C , pH= 10
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 20 40 60 80 100 120 140
permeatebronconc.(ppm)
Time(min)

16. Conclusion
The outcome of this work implies that:
 The % boron rejection was observed to increase with
increase in pH from normal to higher pH which is in
accordance to the theoretical predictions
 On increasing the feed pressure, the % boron rejection
was observed to increase accordingly.

17. References
 C D Tagle , V J R Ternero, A M D Torres Boron removal efficiency in small
seawater Reverse Osmosis systems, Desalination 265 (2011) 43–48
 Alyson Sagle and Benny Freeman, Fundamentals of Membranes for Water
Treatment.
 B. Panete, L.G. Rodriguizw Current trends and future prospects in the design of
seawater reverse osmosis desalination technology, desalination, volume208.
 A. E. Ylmaz, R. Boncukcuoğlu, M.Kocake, E. Kocadağistan, An empirical model
for kinetics of boron removal from boron containing wastewaters by the electro
coagulation method in a batch reactor, Desalination 230 (2008) 288–297.
 M. Htun O, L.Song Effect of pH. and ionic strength on boron removal by RO
membranes, Desalination 246 (2009) 605–612.
 Drinking Water Health Advisory For Boron, EPA