PRESENTATION ON

Conducting polymer membrane for the treatment of perchlorate ion in waste water

INTZAR ALI 13-PSTM-017

DEPARTMENT OF APPLIED

CHEMISTRY

CONTENTS Introduction

Effect of Perchlorate Ion on Health

Origin of problem

Basic principle

Preparation of Conducting Polymer Membrane

Types of Membrane

Membrane filtration depending upon pore size

Conclusions

INTRODUCTION

Conductive polymers are organic polymers that

conduct electricity Such compounds may have metallic conductivity

or can be semiconductors.

Perchlorates are the salts derived from perchloric acid —in particular

when referencing the polyatomic anions found in solution,

perchlorate is often written with the formula ClO4−.

Perchlorate ion has tetrahedral structure.

Separation process can be done by making electrodes by using anionic

and cationic conducting polymer membranes.

Bonding and structure of Perchlorate ion

Effect of Perchlorate Ion on Health

Perchlorate is a powerful competitive inhibitor of the thyroid sodium-iodide symporter.

Perchlorate can temporarily inhibit the thyroid gland's ability to absorb iodine from the bloodstream ("iodide uptake inhibition", thus perchlorate is a known goitrogen) .

it is neither stored nor metabolized, any effects of perchlorate on the thyroid gland are fully reversible.Less clear are the effects of perchlorate on foetuses, newborns, and children.

Diseases Goitre Caused by Perchlorate ion

ORIGIN OF PROBLEM

Most water is disinfected for human consumption.

According to 2007 world health organization (WHO) report-:

1.1 billion people lack access to an improved drinking water supply.

1.8 million people die from diarrheal disease each year.

88% of the 4 billion annual cases of diarrheal disease are attributed to unsafe water.

The first experiments into water filtration were made in the 17th century.

Sir Francis Bacon attempted to desalinate sea water by passing the flow through a sand filter.

Antoine van Leeuwenhoek and Robert Hooke, used microscope to observe for the first time small material particles that lay suspended in the water.

Many process were done in this field to purify waste water e.g.

a) Ion exchange

b) Membrane technology

Ion exchange:

Ion exchange systems use ion exchange resin - or zeolite -packed columns to replace unwanted ions.

The most common case is water softening consisting of removal of Ca2+ and Mg2+ ions replacing them with soap friendly Na+ or K+ ions.

Ion exchange resins are also used to remove toxic ions such as nitrite, lead, mercury, arsenic and many others.

Ion

Exchange

mechanism

Membrane technology Membrane filters are widely used for filtering both drinking water and sewage.

For drinking water, membrane filters can remove virtually all particles larger than 0.2 um.

Membrane filters are an effective form of tertiary treatment when it is desired to reuse the water for industry, for limited domestic purposes, or before discharging the water into a river that is used by towns further downstream.

They are widely used in industry, particularly for beverage preparation (including bottled water).

Basic Principle

The waste water containing perchlorate and other ions is passed through conducting polymer membranes.

The conducting Polymer membrane works as electrodes, the ions are attracted to electrodes with an opposite electric charge and finally water becomes demineralized .

Membranes can be constructed to permit selective passage of either anions or cations.

Mechanism of filtration of waste water

Types Of Membrane

Synthetic membrane Natural membrane

Reverse Osmosis

Mechanical pressure is applied to an impure solution to force pure water through a semi-permeable membrane.

Reverse osmosis is theoretically the most thorough method of large scale water purification.

Although perfect semi-permeable membranes are difficult to create.Unless membranes are well-maintained, algae and other life forms can colonize the membranes.

Membrane Filtration depending upon pore size

Reverse Osmosis

Ultrafiltration

In Ultrafiltration, membranes are used as polymer membranes with chemically formed microscopic pores.

This membrane can be used to filter out dissolved substances avoiding the use of coagulants.

The type of membrane media determines how much pressure is needed to drive the water through and what sizes of micro-organisms can be filtered out.

Nanofiltration

with low total dissolved solids water such as surface water and fresh groundwater.

Removes polyvalent cations.

Removes disinfection by-product precursors such as natural organic matter and synthetic organic matter.Nanofiltration is a relatively recent membrane filtration process used most often

Microfiltration

Contaminated fluid is passed through a special pore-sized membrane.

It can separate microorganisms and suspended particles from process liquid.

It is commonly used in conjunction with various other separation processes such as ultrafiltration and reverse osmosis.

Provide a product stream which is free of undesired contaminants.

Comparative Filtration Chart according to pore size of Membrane

Conclusion

Conducting Polymer membrane may provides effective removal of perchlorate and as well as other ions .

The efficiency may be same or different depending upon size and charge on the ions.

Conducting Polymer membrane can be effectively used in future as it is of very low cost, high tensile strength, high permeability, etc.

[1] E.T. Urbansky, M.R. Schock, Journal of Environmental Management 56 (1999)79–95.

[2] R. Perciasepe, Federal Register 63 (1998) 10273.

[3] USEPA, EPA Sets Reference Dose for Perchlorate, 2005.  [4] J.H. Espenson, The problem and perversity of perchlorate, in: E.T.

Urbansky

References:

  [5] B. Gu, W. Dong, G.M. Brown, D.R. Cole, Environmental

Science & Technology37 (2003) 2291–2295.

[6] A.M. Moore, C.H. DeLeon, T.M. Young, Environmental Science & Technology 37

(2003) 3189–3198.  [7] G.G. Lang, G. Horanyi, Journal of Electroanalytical Chemistry

552 (2003)197–211.

[8] E.T.Urbansky, Perchlorate in the Environment, KluwerAcademic/Plenum Publishers,New York, NY, 2000, p.

Options, The Interstate Technology and Regulato

THANK YOU