Released on = February 15, 2006, 10:08 pm

Press Release Author = Ms Papita Saha.

Industry = Environment

Press Release Summary = The textile wastes are created by:
a. During operation consists of weaving, dyeing, printing & finishing.
b. During sizing of filers, Kiering.
c. During desizing the woven cloth.
d. During bleaching, mercerizing, dyeing & printing.

Chemical precipitation helps to remove 80 - 90% total suspended matters, 40 - 70%
BOD, 30 - 60% COD, 80 - 90% of bacteria from effluent by chemical treatment which
involves coagulation and flocculation. Coagulation is a process by which colloidal
particles are destabilized and is achieved mainly by neutralizing their electric
charge. Flocculation is the massing together of discharge particles as stirring
brings them into contact with one another. The additions of some coagulants help to
reduce the thickness of the diffuse electric layer and thereby reduce zeta
potential. Some important chemical or inorganic coagulants used in Waste Water
Treatment of Textile effluent are:
Alum Al2(SO4¬)3, 18 H2O.
Lime Ca(OH)2
Ferric Chloride FeCl3
Ferrous Sulphate FeSo4, 7H2O



Press Release Body =
Chemical precipitation in waste water treatment involves the addition of chemical
to alter the physical state of dissolved and suspended solids and to facilitate
their removal by sedimentation.

Treatment with coagulants involves i) Lime (5%), alum (5%). ii) Lime (5%),
ferric chloride (0.025%) and alum (5%), iii) Lime (5%), ferrous sulphate
(5%).

From Experimental Results it is observed that lime and alum treatment helps
to remove 83.9 % turbidity, 95.16% Total Suspended Solids, 24.49% total
solids, 85.71% Biochemical Oxygen Demand, 86.36% Chemical Oxygen Demand,
nearly 100% of Oil & grease. On the other hand, lime and ferrous sulphate
help to remove 57.14% turbidity, 83.87% Total Suspended Solids, 43.30% total
solids, 19.04% Biochemical Oxygen Demand, 72.72% Chemical Oxygen Demand,
nearly 70% of Oil & grease. Another Chemical treatment named lime, Ferric
Chloride and alum treatment help to remove 67.85 % turbidity, 70.96% Total
Suspended Solids, 27.56% total solids, 38.09% Biochemical Oxygen Demand,
63.63% Chemical Oxygen Demand, nearly 80% of Oil & grease.

It is also observed from that lime and alum treatment has maximum % of
removal efficiency of TSS, BOD, COD, Oil & Grease than other two chemical
treatments. It transpires that the lime and alum treatment will be
economically viable and acceptable by textile industry.

Web Site = http://geocities.com/papitasaha

Contact Details = Papita Saha.
Nimta
Kolkata - 700049, India
E-mail: papitasaha@gmail.com