|Title of Invention||
"A PROCESS FOR PRODUCING POTABLE WATER"
|Abstract||The present invention relates to a process for removal of arsenic from contaminated or drinking water by use of mixture of steel wool and clean and dried river sand. The steel wool may be prepared from the waste generated by steel plant. The steel wool is crushed and is the mixed with clean and dried river sand. Water contaminated with different forms of arsenic is kept in contact with steel wool and sand mixture, taking about 15g of Mixture per one liter of contaminated/drinking water, for o approximately 2 hours in a thermostatic shaker, at around 35 C. The treated water is then filtered through clean sand at a constant flow rate of 2..... 4 litres per hour. The various forms of arsenic are removed from water to the extent of more than 99%.|
|Full Text||FIELD OF INVENTION
preparation of potable water by
The present invention relates to a process for the/removal of arsenic from contaminated or drinking water.
Arsenic is known to cause toxicity in drinking water. The systems known in the art for removal of arsenic from water are based upon using of activated alumina or by using ceramic filters.
A disadvantage of using above mentioned systems is that these systems do not remove arsenic to desired level.
Another disadvantage of using above mentioned systems is that there is better removal of arsenic(V) as compared to arsenic(III), which is four times more toxic.
Another process known in the art for removal of arsenic from water is by using chemically treated alumina.
A disadvantage of using above process is that it leaches other harmful chemicals in the water.
Another disadvantage of using above process is that it is expensive.
Another arsenic removal technology uses iron and manganese oxide coated sand.
The disadvantage of this technology is that it leaches undesirable manganese and iron in drinking water.
Still another technology known in the art uses iron fines and silica sand for removal of arsenic from water.
A disadvantage of this technology is that the arsenic removal is carried out under anaerobic conditions and so is expensive.
Another disadvantage of using the above technology is that it is very complicated.
c:> mixing crushed steel wool and washed ? the range of 7s3 to 2:3,
d) mixing in s grinder at a temperature range of .1(3 to 45 C»
e) mixing sand and steel wool mixture with contaminated water and
shaking the contents for half an hour to two hours with the pH
range of 6-10,
f) allowing the contents to settle and the supernatant being
filtered through clean sand at a constant flow rate of 2-4
litres per hour.
The invention will now be illustrated with a working example which is intended to foe a typical example to illustrate the working of the invention and is not intended to be taken restrict!vely to imply any limitation on the scope of the present invention.
For the preparation of 1kg batch of steel wool-sand mixture,
river sand was washed thoroughly with analytical grade Milli-Q
o water and dried in an oven at a temperature of 110 C for
approximately 24 hours, till constant weight is achieved. 500 gm of steel wool was crushed in a grinder for 10 minutes and then it was mixed with 500 gm of washed and dried sand. It was mixed properly at ambient temperature in a mixer grinder for .15 minute. The final mixture so obtained was evaluated for its performance for the removal of arsenic from water in the following manner.
15g of the mixture prepared SB above was added to 100ml of Ippm
(parts per million) synthetic; solution of different forms of
arsenic compounds and real contaminated ground water 600ppb) in stoppered glass bottles. The contents were shaken for
helf an hour- to two hours on s thermastatic shaker, at a
o temperature of 35 C. The solutions were allowed to settle and
then filtered through 10 cjm of clean sand at a flow rate of 2-4 litres per hour. The filtered water was free from arsenic and other undesirable contaminants specially iron.
Arsenic concentration before and after adsorption is determined by using GBC-HG-3000 atomic absorption spectrophotometer.
Results of water analysis (Table Remove)
BDL - below detectable limit, ND - not detected.
It is clear from the foregoing description and the analytical data that the steel wool and sand mixture is highly effective for removal of arsenic from drinking water. It is inexpensive, easy to use and environmental friendly as the spent material can be used for other applications such as for making standard grade concrete blocks.
It is to be understood that the process of the present invention is susceptible to modifications, changes and adaptations by those skilled in the art. Such modifications, changes, adaptations are intended to be within the scope of the present invention which is further set forth under the following claims:-
1. A process for producing potable water by removal of all forms
of arsenic from contaminated or drinking water wherein the
process comprises of following steps:
a) washing and drying the river sand till constant weight is achi eved.
b) Crushing the steel wool into small pieces to convert it into
form of fine fibres.
c) Mixing clean and dried sancl and steel wool in a grinder.
d) Shaking the contaminated/drinking water with mixture of steel
wool fibres and clean & dried sand and allowing it to settle.
(?) Filtering the supernatant through clean sand at a constant flow rate of 2 to 4 litres per hour.
2, A process as claimed in claim 1 wherein the said drying of
o sand is carried out around 110 C.
3. A process ss claimed in claim 1 wherein the ratio of steel
wool fibres to sand is in the range of 7s3 to 2s3 preferably
4, A process as claimed in claim 1 wherein said mixing of sand
and steel wool fibres is carried out at temperature of 10 to
45 C preferably at 20 to 35 C-
OBJECTS OF HHE INWEMTION
'The main object of the present invention is to propose a process for the preparation of potable water by removal of arsenic from contaminated or drinking water.
Another object of the present invention is to propose a process for the preparation of potable water by removal of arsenic, wherein all forms of arsenic vis. Arsenic Still another object of the present invention is to propose a process the preparation of potable water by removal of arsenic, wherein the leaching of harmful chemicals is eliminated cotnp 1 ete ly .
Yet another object of the present invention is to propose & process the preparation of potable water by removal of arsenic, which is inexpensive as it utilises the waste generated by steel p 1 ant.
According to this invention there is provided s process for preparation of potable water by removal of arsenic from contaminated water comprising in the steps of:
a) washing river sand thoroughly and air dried in an oven till
we i gh t i s ac: h i e v e d ,
b) crushing steel wool into small pieces,
5» A process as claimed in claim 1 wherein the steel wool fibres and sand mixture is taken in quantities of 5 - 80 Q per litre preferably 15g per litre of drinking/contaminated water.
6. A process as claimed in claim i wherein the said shaking of
steel wool and Band mixture with contaminated/drinking water
o is carried at around 35 C for about 2 hours.
7. A process as claimed in claim 1 wherein pH of the solution of
contaminated/drinking water and the mixture of steel wool
fibres and sand is between 6 - 10.
8. A process for producing potable water by removal of all forms
of arsenic from contaminated or drinking water as
substantially described and illustrated herein.
|Indian Patent Application Number||143/DEL/2002|
|PG Journal Number||32/2008|
|Date of Filing||25-Feb-2002|
|Name of Patentee||ADDITIONAL DIRECTOR (IPR)|
|Applicant Address||DEFENCE RESEARCH & DEVELOPMENT ORGANISATION MINISTRY OF DEFENCE, GOVT OF INDIA, B-341, SENA BHAWAN,DHQ P.O. NEW DELHI-110011|
|PCT International Classification Number||C02F 1/62|
|PCT International Application Number||N/A|
|PCT International Filing date|