The document summarizes a study on treating oily wastewater from a metal industry's cutting fluid in Indore City, India. The study tested various coagulants for removing total suspended solids (TSS), total dissolved solids (TDS), and oil and grease. Poly aluminum chloride was found to be the most effective coagulant, removing up to 89.6% of TSS, 42.2% of TDS, and 88.8% of oil and grease. Acidification of the wastewater to pH 4 prior to coagulation treatment was found to maximize oil removal. The study concludes that chemical treatment using coagulation after acidification is an effective way to remove contaminants from o
1. IWWA 51st Annual Convention Indore
TREATMENT of OILY WASTEWATER in CUTTING FLUID of a
METAL INDUSTRY in INDORE CITY
Sonal Garg Dr. D.J.Killedar Apurva Pandey
Asst. Professor Professor Former M.Tech student
CE-AMD CE-AMD CE-AMD
S.G.S.I.T.S S.G.S.I.T.S S.G.S.I.T.S
INDORE [M.P.] INDORE [M.P.] INDORE [M.P.]
2. INTRODUCTION
• Wastewater obtained from industries is generally much more polluted than
domestic or even commercial wastewater. Still several industries try to
discharge their effluents into our natural river streams through unauthorized
direct discharges.
• Such a tendency on the part of the industries may pollute the entire river water
to a great extent thereby making its purification almost an impossible task.
Sometimes the industries discharge their polluted wastewater into municipal
sewers thereby making the task of treating that municipal sewage a very
difficult and costly exercise.
• The industries are therefore generally prevented by legal laws from discharging
their untreated effluents. It therefore become necessary for the industries to treat
their wastewater in the individual treatment plant before discharging their
effluent either on land or lakes or rivers or in municipal sewers.
• Since, oil and grease present in oily wastewater consist of free oil, TSS and
TDS which are harmful for natural environment, so when untreated wastewater
is discharged into natural river or streams, it proves hazardous for aquatic life.
3. CUTTING FLUID
• Cutting fluid is a type of coolant and lubricant designed
specifically for metal working processes, such
as machining and stamping.
• There are various kinds of cutting fluids, which include
oils, oil-water emulsions, pastes, gels, aerosols (mists),
and air or other gases.
• They may be made from petroleum distillates, animal
fats, plant oils, water and air, or other raw ingredients.
Depending on context and on which type of cutting fluid
is being considered, it may be referred to as cutting
fluid, cutting oil, cutting compound, coolant, or lubricant.
4. • In order to protect our natural environment, oily wastewater
needs to be treated so as to minimize the concentration of
TDS, TSS and oil & grease present in it.
• The project has been taken to find ways to treat oily
wastewater present in cutting fluid economically by chemical
treatment.
• This study was done to determine the coagulant best suited for
chemical treatment of emulsified oil, it’s optimum pH and
optimum dosage for removal of TSS & TDS by jar test.
NEED OF STUDY
5. STUDY AREA
The field work was conducted at “BHARAT METAL ENGINEERS”
industry situated at Rambali Nagar industrial area near Scheme No. 51 at
Indore city.
6. METHODOLOGY ADOPTED
Treatability tests for removal of different parameters using coagulants by Jar
Test
Determination of optimum pH of raw wastewater by acidification
Preparation of different doses of coagulants
Selection of different coagulants
Determination of physico-chemical characteristics of raw effluent
Collection of sample
7. Characteristics of raw effluent of cutting fluid
S. No. Parameters Concentration
1 pH 8.5
2 COD 700 mg/l
3 TSS 6750 mg/l
4 TDS 32400 mg/l
5 Oil & Grease 173.20 mg/l
9. Weight of coagulants add in 25 ml distilled water to make standard solution
S. No.
Standard solution
concentration
(in mg/L)
Alum
(in gm)
FeCl3
(in gm)
PAC
(in gm)
1 10 0.75 0.14 0.18
2 20 1.50 0.28 0.36
3 30 2.25 0.42 0.54
4 40 3.00 0.56 0.72
5 50 3.75 0.70 0.90
Preparations of different doses of coagulants
10. Determination of optimum pH of wastewater by
acidification
Check the concentration of oil & grease in bottom layer decanted water at
different pH values
Mixture separates in 2 layers
Oily material concentrates in upper layer Water separates on bottom layer
Place the sample in separating funnel & allow to settle
pH of sample was reduced from 8.5 to 2, 3, 4, 5, 6, 7 and
8 by adding appropriate amount of conc. HCl (Acid
allows the oil droplets to agglomerate)
100 ml of wastewater sample was collected
Oil and water separation was done by destabilizing cutting fluid emulsion and
separating it in two layers, one is water and other is oil material present by
addition of acid.
11. S. No. Parameters
Wastewater characteristics at different pH after acidification
pH=8.5 pH= 2 pH=3 pH=4 pH=5 pH =6 pH =7 pH= 8
1
Oil & Grease
(in mg/l)
173.20 60 62.60 58.6 74.3 68.2 72.7 75.8
2
TDS
(in mg/l)
32400 15900 24620 27600 31900 11450 26500 28690
3
TSS
(in mg/l)
6750 1400 1600 1300 1000 1100 1250 1500
4
COD
(in mg/l)
700 640 600 680 520 600 m 380 560
12. Treatability tests for removal of different physico-
chemical parameters using coagulants by Jar Test
Jar test method determines optimum dosage of coagulant (single/mixed),
coagulant aids for removal of TSS, TDS and oil & grease caused by colloidal
and non settleable particles followed by sedimentation under quiescent
condition.
RM:
100 rpm, 1 min
SM:
30 rpm, 20 min
21. CONCLUSIONS
On the basis of study of some aspects of treatment of emulsion oil present in
cutting fluid by acidification and coagulation through chemical treatment, the
following conclusions can be drawn-
In this study, it has been found that the ‘Acid cracking’ is a suitable method to
remove the maximum oil droplets at pH=4 from the effluent.
The Oil & Grease concentration decreased drastically in the acidification
process as compared to the decrease in concentration of TSS & TDS.
The coagulation process after acidification process applied in order to remove
contaminants from wastewater appeared very effective.
The study shows that Poly aluminum chloride is very efficient in removal of
the TSS and TDS from oily wastewater as compared to other coagulants used.
It was found that among three coagulants studied viz. Alum, FeCl3 and Poly
aluminum chloride, Poly aluminum chloride gave the best result and removed
maximum concentration of contaminates i.e. 89.6% TSS, 42.2% TDS and
88.8% Oil and grease.