Industrial Emulsified Acidic Water: Sources, Composition and Pollutants

1. Sources and characteristics of emulsified acidic water

Sources: electric desalter effluent, acid pickling wastewater, catalytic cracking sour water and similar streams.

Typical composition: oils such as emulsified oil and dissolved oil; acidic substances such as H₂SO₄, HCl and H₂S (pH 1-4).

Pollutants: heavy metals (Fe, Ni), sulphides and phenols.

2. Demulsification and oil removal processes for acidic water

Acidification demulsification: acid such as H₂SO₄ is added to adjust the pH to 2-3, destabilising the emulsifier and releasing free oil.

Chemical demulsifier: polyether type (such as PE-6000) or aluminium salt (PAC) dosed at 50-200 mg/L.

Gravity oil separation: 1-2 hours of retention to remove free oil;

Flotation: dissolved air flotation (DAF) removes more than 80% of the emulsified oil.

3. The SINOKLE high-efficiency treatment process

SINOKLE uses its own developed products in a combined new process to treat emulsified acidic water efficiently and in an environmentally sound way, meeting customer requirements.

High-efficiency coalescing oil separator:

A patented product of the company, it uses the coarse-graining principle, the shallow-pool principle and CFD simulation to optimise the internal space and structure of the vessel, rationally laying out the internal flow field so that oil droplets or suspended solids rapidly gather, coalesce, rise (or settle) and separate in the water.

The vessel interior consists of an inlet pre-separation zone, a primary separation zone and a main separation zone. The inlet zone contains a specially designed cyclonic separation device, the primary and main zones are packed with coalescing media of different specifications, and an oil collection header is provided at the top of the vessel with a high-efficiency sand-flushing and sludge-discharge device at the bottom.

Compact structure and small footprint with high oil removal efficiency (above 90%); the internal packing uses a patented structural design and is available in stainless steel or reinforced PP, giving high strength and long service life; the specially designed sand-flushing and sludge-discharge device keeps the packing unclogged and the equipment free of sludge build-up; fully enclosed automatic operation under pressure is stable, safe and reliable.

Cyclonic dissolved air flotation (CDFU):

a new generation of green, high-efficiency vertical-tank flotation equipment developed by the company. It integrates cyclonic centrifugal separation, ultrafine bubble generation and dissolved air flotation, and through the organic combination of these technologies achieves efficient, rapid separation of waste oil, emulsified oil and suspended solids from wastewater.

Integrating several technologies in one unit, it achieves oil removal above 90% and SS removal above 85%; no chemicals are used, demulsification is purely physical and no oily sludge is produced; the equipment is skid-mounted, automated and digitalised, with remote expert service available; it operates sealed under pressure, safely and cleanly.

4. Acidic water treatment site

Water quality data:

Inlet oil content: 150,000 ppm or less

Outlet oil content: 100 ppm or less