Automotive WWTP addresses complex effluent from multi-stage surface treatment in modern car production. Sources: stamping, welding, phosphating (Bonderite), cataphoresis (E-coat), primer/topcoat, engine assembly and testing.
Auto wastewater has COD 800-3,500 mg/L, oil-grease 50-500 mg/L, phosphate 50-300 mg/L, heavy metals (Zn, Ni, Cr, Mn) 5-50 mg/L. pH swings from 2 (phosphating) to 11 (alkaline degrease).
Arsistek auto sector solutions combine stream segregation, oil separation (API/CPI/DAF), heavy metal precipitation, biological treatment and UF/RO recycle. Modern plants target 70-90% water reuse.
Automotive Wastewater Structure
Modern car production has 7-12 surface treatment stages: degreasing (alkaline), phosphating (Bonderite, acidic), passivation, cataphoresis (E-coat), primer, topcoat, clearcoat — each rinse contributes effluent.
Surface treatment streams carry Zn, Fe, Mn, Ni with phosphate. E-coat epoxy residues raise COD. Paint lines contribute VOC residues.
Test (engine-test, A/C) and service waters bring high oil-grease, moderate organic load. Stream segregation + stream-specific pretreatment is essential.
Oil Separation Systems
High oil-grease streams (service, test, machine wash) first pass through API separator — free oil removed.
CPI follows for emulsified oil. Stable emulsions broken with chemicals + DAF. Total oil removal 95%+.
Heavy Metal Precipitation
Zn, Fe, Ni from surface treatment precipitated at alkaline pH 9-10 as hydroxides.
Stricter limits: sulfide precipitation or ion exchange. Sludge belt-pressed and sent to licensed disposal.
Water Reuse and Zero Liquid Discharge
Auto sector leads zero liquid discharge (ZLD). Premium plants worldwide achieve 95%+ water reuse.
Treated effluent goes through UF + RO. Permeate below 1,000 µS/cm returns to rinses, cooling towers, E-coat dilution.
RO concentrate is sent to evaporator + crystallizer producing solid salt — the final ZLD step. No liquid leaves the site.
Auto Sector Solution Advantages
Automotive References
8 images coming soon — stay tuned for our reference projects and facility photos.
Frequently Asked Questions
Acidic phosphating (pH 2), alkaline degrease (pH 11), oily service and neutral paint streams have very different compositions. Mixing causes chemical interaction, corrosion and inefficiency.
Yes. Many premium-brand auto plants (Mercedes, BMW, Toyota) run ZLD. CAPEX is 2-3x standard but pays back via tender scoring, ESG credits and long-term water cost savings.
Chemical precipitation (calcium/aluminum salts) + biological P-removal achieves <2 mg/L.
Preferably yes. Contains VOC, pigments, resins. Dedicated UF + GAC + Fenton pretreatment before joining the main biological stage.
Depends on capacity, reuse target and ZLD level. Plant-specific engineering study required for detailed budget.
Multiple projects for Turkish auto majors and Tier-1 suppliers in surface treatment WWTP. References shared under NDA.