ETP Phase-II

ARL Up-gradation of Effluent Wastewater Treatment Plant (ETP

Phase-II)

A sustainable Environmental InitiativeMuhammad Fahad

KhanAttock Refinery Ltd.

Introduction

Enhance capacity of effluent treatment system.

Compliance with the National Environment Quality Standards (NEQS), in view of future expansion.

Addition of secondary treatment system.

Brief Description API separators for separation of oil from effluent

water. (C-Separator, D-Separator, B-Separator)

From separators, oil pumps to oil treatment tanks & effluent water flows towards large sump called C-Sump.

Form C-Sump effluent pumps to existing effluent treatment plant.

Effluent from C-Sump first treats in 2 # parallel 100 gpm SRC (Slant Rib Coalescing) units, here oil & sludge, after separation, recycled to C-Sump and onward pumps to oil treatment tanks.

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(cont.) At downstream of SRC unit we have 100

gpm DAF (Dissolved Air Floatation) unit, for chemical treatment of effluent.

Coagulation & Flocculation phenomenon to remove oil, grease & organic contents present in effluent.

Reduce BOD, COD, O&G contents. From DAF unit separated O&G contents pumped to

C-Sump & then to oil treatment tanks.

At the end treated water at DAF outlet, released from refinery after meeting National Environment Quality Standards.

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Block flow diagram of ETP-I

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SRC Unit

C & D-Separator

Slop Oil Tanks

C-Sump

Waste Water

Oil

Water

Oil O & G

DAF Unit

Treated Water Released from

Refinery

Demulsifier

FFO TanksOR

Oil for Reprocessing

Water

O & G

Coagulant

Flocculent

Alum Polymer

Influent

White Water Vessel

White Water

Clear Water

DAF Sludge

Upgraded API Separators

Existing API separators (C, D & Vac.) are upgraded.

Scrapper system removed the settled solids & sludge.

Pumping of sludge to drying beds. 1st stage oil skimmer system remove free floating oil. Pumping of removed oil to oil collection tanks.

Oil coalescers to coalesce the small droplets of oil in water.

2nd stage oil skimmer to remove the coalesced oil droplets.

Pumping of removed oil to oil collection tank.

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Block Flow Diagram of Upgraded API Separators

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Waste WaterScrapper System

Oil Skimmer-I

Sludge Drying Bed

Oil Tank

Oil

Oil Skimmer

Oil Coalescer

Effluent Flow to C-Sump*

Oil Skimmer-II

Oil

Slop Oil Tank

Sludge

ETP-II Section Vise

Capacity 200 USGPM

Primary Treatment Chemical treatment using DAF.

Secondary Treatment Biological treatment using activated

sludge system and secondary calarifier.

Sludge Treatment Gravity sludge thickener, sludge holding

tank and filter press.

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Primary Treatment

Chemical Treatment pH adjustment to favor the onward

chemical reactions. Coagulants dosage to react with

fine suspended solids to form flocs. Flocculants dosage to form large

clumps of loose flocs.

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(cont.)

Dissolved Air Floatation System Removal of generated flocs & suspended

solids. Pressurized water saturated with air

injects to the DAF tank. Fine bubbles formed, attach with flocs and

suspended solids, bring them on surface. Surface particles removed mechanically or

overflowed Removed particles treats as primary

sludge & transferred to filter press.

Secondary Treatment

Biological treatment process.

Aeration Tank Conventional activated sludge system to favor

micro-organism growth. Micro-organisms uptake BOD and COD load

present in wastewater for metabolic growth. Supply of air/oxygen for micro-organism

growth. Maintaining of MLSS (2800 – 3500 mg/l) by

recycling part of activated sludge from secondary clarifier.

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(cont.)

Secondary Clarifier Remove the solids by

sedimentation process. Recycle part of sludge to aeration

tank to keep continue the treatment process.

Treated effluent meeting national environment and quality standards, will released from refinery to polishing pond.

Sludge Treatment Sludge collected from secondary

clarifier thickens by filtering the water out of the sludge.

Pumping of reduced volume sludge to sludge holding tank.

Filter press will use to eliminate the moisture content of sludge up to 30 % and to produce cake.

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Process Flow Diagram @ C-Sump

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Scrapper System

Oil Skimmer-I

Sludge Drying Bed

Oil Tank

Oil

Oil Skimmer

Oil Coalescer

Effluent o ETP-II

Oil Skimmer-II

Oil

Slop Oil Tank

Sludge

(cont.)

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Effluent Meeting NEQS

Pre-DAF

Acid/Alkali

Flocculent

Coagulant

DAF UNIT

White Water

Primary Sludge

~25% COD & BOD Removed~90% TSS/O&G Removed

Activated Sludge System

Secondary Clarifier

Comparison Automate the removal of sludge & solids to

minimize manual handling. Automate removal of free oil to minimize manual

handling. Increase the overall efficiency and effectiveness

of the API Separators to achieve 80% removal of oil.

Increased capacity for effluent treatment system to cater the future scenario.

Improved quality of treated effluent by utilizing the secondary treatment technology, even this effluent will use for aquatic life.

ETP-II

THANKS Q . . . ?