WWT Sludge:

Solution that is generated during the zinc phosphate conversion coating process of automobiles is sent 

to WWT treatment plant. This solution contains the following components:

Iron Oxide (Fe2O3 or FeO) (36.97%), 

Calcium Oxide (10.62%), 

Aluminum Oxide (0.55%), 

Magnesium Oxide (3.93%), 

Zinc Oxide (8.56%) 

Nickel Oxide (4.43%)

During the WWT treatment process NaOH is used to convert metals to hydroxides and then a

flocculating agent (ferric chloride or polymeric substance) is used to precipitate these metals. 
Description Honda (Greensburg, In.)

Date 7/28/10

Constituent % TSCA Chemical CAS No.

CaO 10.62 Calcium hydroxide (Ca(OH)2) 1305620

SiO2 2.62

Al203 0.55 Aluminum hydroxide (Al(OH)3) 21645512

Fe2O3 36.97 Iron hydroxide (Fe(OH)3) 1309337

MgO 3.93 Magnesium hydroxide (Mg(OH)2) 1309428

SO3 0.45

Na2O 1.96

K2O 1.28

TiO2 1.28

P2O5 25.26

Mn2O3 1.68

SrO 0.08

Cl 0.24

F ND

V2O5 ND

CR2O3 ND

ZnO 8.56 Zinc Hydroxide (Zn(OH)2) 20427581

CuO ND

Br ND

NiO 4.43 Nickel hydroxide (Ni(OH)2) 12054487

ZrO2 ND

Ga2O3 ND

Co3O4 ND

SnO2 0.1

Bi2O3 ND

Y2O3 ND

I ND

HfO2 ND

Nb2O5 ND

As2o3 ND

PbO ND

GeO2 ND

Rb2O ND

MoO3 ND

TI2O3 ND

SeO2 ND

WO3 ND

CeO2 ND

Sb2O3 ND

CeO2 ND

Sb2O3 ND
Pre-Cleaning Degrease Rinse Rinse Conditioning Phosphate Rinse Dip Rinse Rin

Pre-Cleaning Degrease Rinse

Conditioning Phosphate Rinse Dip Rinse 

FromWeld

Regulated metals (Zn, Ni) in current PA processrequire industrial wastewater treatment in plant FAC

Chemistry of phosphatingFe + 2H3 PO4 Fe(H2 PO4)2 + H2Zn(H2 PO4 )2 ZnHPO4 + H3 PO4

3ZnHPO4 Zn3 (PO4 )2 + H3 PO4

Zn(H2 PO4 )2 , 

Ni(NO3 )2 , HF

Plant FACIndustrialWastewaterTreatmentSystem

110

0

F

Situation Analysis 
Primer/Surfacer Pit

Clearcoat PitTopcoat Pit#1 DIW Rinse

#2 DIW Rinse

Influent Metals

Sump

Treatment

Chemicals

P

P

(2) Pumps

(3) Raw Metals Batch Treatment Tanks

150,000 Gallon Capacity Each

P

P

Flow Meter

(2) Pumps

Gravity Settler

55 Gal.

Drum

Polymer Feed

System

P

P

(2) Pumps

PolymerAddition

Combined Sludge Tank

35,000 Gallon Capacity

Anionic Cationic

E-Coat Tank

#1 Permeate

#2 Permeate#3 Permeate#4 Permeate

Stage 8 #4 Water RinseStage 9 #5 Water RinseStage 7 #3 Water RinseStage 6 PhosphateStage 5 Surface ConditionerStage 4 #2 Water RinseStage 3 #1 Water RinseStage 2 Main CleanStage 1 Pre-CleanBumper Paint PlantAnolyte#4 DIW Rinse#3 DIW Rinse

pH Adjustment

Chemistry of waste treatmentZn++ + NaOH Zn(OH)2 + Na+Metal hydroxide sludge generation

PA MAP & ELP FAC Industrial Wastewater Treatme

FAC

Chelation of heavy metals by EDTA in PA Degreaser

makes it very difficult and costly to break the bonds,

and capture from solution as metal hydroxide precipitate
Honda Marysville

Line 1 Pretreat

Stage 4 

#1 water rinse

Stage 3 

Clean Dip tank 

Stage 2 

Pre-Clean sprays

Stage 1 

Pre-water dip

Stage 5 

#2 water rinse

Stage 6 

Surface Conditioner

Stage 7 

Phosphate dip tank

Stage 10 

#1DI water rinse

Stage 11 

#2 DI water rinse

Stage 9 

water dip rinse 

33,300 gallons 15,300 gallons 1,500 gallon sub tank 33,000 gallons 4,100 gallon sub tank 15,300 gallons

1,500 gallon

15,200 gallons

1,500 gallon sub tank

Sub tank

1,500 gallon sub tank 1,500 gallon sub tank OLD PHOSPHATE OVEN

Sprays off Sprays off Dip empty Sprays off

Stage 4 

#1 water rinse

Stage 3 

Clean Dip tank 

Stage 2 

Pre-Clean sprays

Stage 1 

Pre-water dip

Stage 5 

#2 water rinse

Stage 6 

Surface Conditioner

Stage 7 

Phosphate dip tank

Stage 10 

#1DI water rinse

Stage 11 

#2 DI water rinse

Stage 9 

water dip rinse 

33,300 gallons 15,300 gallons 1,500 gallon sub tank 33,000 gallons 4,100 gallon sub tank 15,300 gallons

1,500 gallon

15,200 gallons

1,500 gallon sub tank

Sub tank

1,500 gallon sub tank 1,500 gallon sub tank OLD PHOSPHATE OVEN

Sprays off Sprays off Dip empty

Stage 4 

#1 water rinse

Stage 3 

Clean Dip tank 

Stage 2 

Pre-Clean sprays

Stage 1 

Pre-water dip

Stage 5 

#2 water rinse

Stage 6 

Surface Conditioner

Stage 7 

Phosphate dip tank

Stage 10 

#1DI water rinse

Stage 11 

#2 DI water rinse

Stage 9 

water dip rinse 

33,300 gallons 15,300 gallons 1,500 gallon sub tank 33,000 gallons 4,100 gallon sub tank 15,300 gallons

1,500 gallon

15,200 gallons

1,500 gallon sub tank

Sub tank

1,500 gallon sub tank 1,500 gallon sub tank OLD PHOSPHATE OVEN

Stage 4 

#1 water rinse

Stage 3 

Clean Dip tank 

Stage 2 

Pre-Clean sprays

Stage 1 

Pre-water dip

Stage 5 

#2 water rinse

Stage 6 

Surface Conditioner

Stage 7 

Phosphate dip tank

Stage 10 

#1DI water rinse

Stage 11 

#2 DI water rinse

Stage 9 

water dip rinse 

33,300 gallons 15,300 gallons 1,500 gallon sub tank 33,000 gallons 4,100 gallon sub tank 15,300 gallons

1,500 gallon

15,200 gallons

1,500 gallon sub tank

Sub tank

1,500 gallon sub tank 1,500 gallon sub tank OLD PHOSPHATE OVEN

Sprays off Sprays off Dip empty Sprays off