Volume 2 • Issue 5 • 1000123
Hydrol Current Res
ISSN: 2157-7587 HYCR, an open access journal
Open Access Research Article
Shastry and Shashidhar, Hydrol Current Res 2011, 2:5
DOI: 10.4172/2157-7587.1000123
Waste Water Treatment Using Eco Friendly Oxidising Agent Fe (VI)
Vidyavati Shastry* and Shashidhar S
Department of Chemistry, SEA College of engineering and Technology, Bangalore, India
*Corresponding author: Dr.Vidyavati Shastry, Department of Chemistry, SEA
College of engineering and Technology, Bangalore, India, E-mail: vidyavati_
kinetic@yahoo.co.in
Received July 29, 2011; Accepted December 08, 2011; Published December
12, 2011
Citation: Shastry V, Shashidhar S (2011) Waste Water Treatment Using Eco
Friendly Oxidising Agent Fe (VI). Hydrol Current Res 2:123. doi:10.4172/2157-
7587.1000123
Copyright: © 2011 Shastry V, et al. This is an open-access article distributed under
the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and
source are credited.
Abstract
Ferrate (Fe (VI)) is a potential water treatment chemical due to its dual functions as an oxidant and a subsequent
coagulant/precipitant as ferric hydroxide. Hence, an application of Fe (VI) to wastewater could achieve both oxidative
elimination of various micro pollutants and reduction in the COD, BOD, Total hardness, Chloride, Fluoride can be
achieved.
The aim of this study was to assess the potential of Fe (VI) to oxidize selected micro pollutants and remove
phosphate during enhanced treatment of municipal waste water in a single treatment step. The waste water from pond
in K.R Puram, Bangalore is treated with powerful eco-friendly oxidizing agent Fe(VI){0.005mg/L}, the parameters
such as, COD, BOD,TSS, Total hardness, chloride, phosphate, ammonia, cyanide etc. are measured before and
after treatment. The reduction in the COD, BOD, Total hardness, Phosphate, Ammonia, Cyanides are observed.
Keywords: Waste water; Fe (VI); Pollutants
Introduction
Water pollution is a serious issue which afects the physical and
economic health of world community. According to W.H.O million
of people sufer illness and death each year due to drinking water
contamination. Filtration and disinfection methods are followed
in water treatment. But fltration is poor barrier for few pollutants.
Disinfection by chemicals gives by-products some of which may be
toxic to human and aquatic health.
In recent years Ferrate (VI) has attained importance as
environmentally friendly oxidizing agent and coagulating agent [1] in
wastewater treatment. Te product Fe (III) is non toxic compound. Fe
(VI) oxidizes toxic chemicals [2], nitrites, glycerol, oxalates, alcohol,
sulphides [3] ether, ammonia [4], urea, many other water soluble and
water insoluble organic compounds, drugs [5] microbes etc., in the pH
range of 6-9. It simultaneously acts as oxidant disinfectant & coagulant
in water treatment.
Fe (VI) is powerful reducing agent it reduces in acids and alkalis.
4 K
2
FeO
4
+ 10 H
2
O → 4 Fe (OH)
3
+3O
2
+ 8KOH
When waste water is treated with Fe (VI) concentrations higher
than 5 mg/L, it eliminates the organic compounds by more than 60%.
It removes phosphates [6] from 2.5 to 0.80mg when the dose of Fe (VI)
is more than 7 mg/L. It oxidises H
2
S to thiosulphate and sulphate at pH
9-11. H
2
S is formed by the incomplete oxidation of organic compounds
which gives bad odour to water and has toxic nature. Te oxidation of
organic pollutants by Fe (VI) incorporated by nature and manmade
activities reduces the COD and BOD of water samples.
3 C
6
H
5
CH
2
OH + 2 K
2
FeO
4
→ 3C
6
H
5
CHO + Fe
2
O
3
+ 4 KOH + H
2
O
8 HFeO
4
-
+ 3 H
2
S + 6 H
2
O → 8 Fe (OH)
3
+ 3 SO
4
2-
+ 2 OH
-
Te level of BOD and COD is an important factor in evaluating the
organic pollutants in waste water. Te discharge of impurities generate
BOD & COD level to 5000-3000 mg/L and COD level to 1000-5000mg/
L but discharge permits only 250mg/L & 500mg/L respectively.
Te aim of our study is to check the water quality in pond and to
treat it with Fe (VI) to remove the pollutants.
Experimental
Preparation of Fe (VI)
All chemicals used were of analytical grade (EMerck) and were
used without further purifcations. To the 250 ml sodium hypochlorite
solution slowly added 25g of ferric nitrate at 25-30 degrees. Te
temperature is maintained at 30 degrees while saturating with NaOH.
Te mixture is then fltered with suction through a coarse fritted
glass flter. Te sodium ferrate fltrate is placed in a 250ml beaker and
immersed in a 20 degree water bath 100ml of saturated KOH solution
is added with stirring. Stirring is continued for 5 minutes, fnally
fltering through a fritted glass flter of medium porosity, the fltrate
being discarded [7].
Te precipitate is leached on the flter with 4-5 10ml portions
of 3 molar KOH solutions. Te residue remaining on the flter has a
light grey cast and is discarded. Te fltrate is transferred to a 250ml
beaker and 50ml of chilled, saturated KOH solution is added. Any solid
potassium ferrate still on the flter disk is washed out with a few ml of
saturated KOH solution. Te fnal solution is approximately 11 molar
in KOH. Te solution is stirred for 5 minutes and then fltered through
medium porosity fritted glass.
Waste water treatment with fe (vi)
Water sample is collected in polythene bottles from the pond
in K.R Puram, Bangalore, INDIA.Water is passed through a series
of process of primary treatment to remove suspended & colloidal
impurities. Ten it is treated with Fe (VI) over a period of 25-30 days.
Te water parameters are recorded regularly.
Hydrology
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ISSN: 2157-7587