Treatment Technologies

How We Select Technology

The Right Technology for Your Wastewater

Technology selection at Critical GREEN begins with characterisation of your wastewater — not a catalogue. Here is how we match technology to application.

High-Strength Industrial (COD >1,000 mg/L)

Anaerobic pre-treatment (UASB or IC Reactor) followed by aerobic polishing (SBR or MBR). Biogas recovery makes the system energy-positive.

UASBIC ReactorSBR

High FOG / Emulsified Effluent

DAF or SAF pre-treatment for fats, oils, and grease removal, followed by biological treatment. CAV-DAF for emulsified streams and colour.

SAFCAV-DAFDAF Flat/Radial

Sewage / Low-Strength (BOD <400 mg/L)

ABR + constructed wetlands for low-cost gravity treatment, or SBR/MBR for NEQS-compliant effluent with reuse potential. Underground option for housing societies.

ABRMBRWetlands

Technology Selection Matrix

Technology	Inlet COD Range	Removal Efficiency	Energy Use	Best For
UASB Reactor	1,000–30,000 mg/L	60–85% COD	Very Low + Biogas	Sugar, Distillery, Food
IC Reactor	5,000–80,000 mg/L	70–90% COD	Very Low + Biogas	Distillery, Paper, Pharma
ABR	150–800 mg/L	70–85% BOD	Zero	Municipal, Housing, Rural
SBR	100–2,000 mg/L	>90% BOD	Medium	Textile, Edible Oil, Municipal
MBR	100–1,500 mg/L	>98% BOD	Medium-High	Housing, Hotels, Reuse
BAF	50–500 mg/L	85–95% BOD	Medium	Municipal, Industrial Polish
SAF / DAF	FOG <2,000 mg/L	>92% FOG	Low-Medium	Edible Oil, Dairy, Food
Constructed Wetlands	50–400 mg/L (post ABR)	70–95% BOD	Zero to Minimal	Municipal, Sugar Polish, Reuse

Process Engineering

Typical Treatment Trains by Industry

🍬

Sugar Mill / Distillery

Screen→ Equalisation→ UASB / IC Reactor→ SBR Polish→ Discharge / Irrigation

UASB achieves 70–85% COD reduction with biogas recovery. SBR polishes to NEQS. Total COD removal >95%.

🧵

Textile & Dyeing

Screen→ CAV-DAF→ SBR→ Multimedia Filter→ Discharge

CAV-DAF removes 60–80% colour and SS. SBR biological stage removes BOD/COD to NEQS. Multimedia filter polishes SS.

🫙

Edible Oil Refinery

Screen→ SAF / DAF→ SBR→ Discharge

SAF removes >95% FOG in pre-treatment. SBR handles residual BOD/COD. NEQS compliance achieved consistently.

🏘️

Housing Society STP

Screen→ MBR→ UV Disinfection→ Irrigation Reuse

MBR produces BOD <5 mg/L, SS ~0 mg/L. UV disinfection for reuse. Installed underground — green area above.

🌾

Rural / Low-Cost Municipal

Screen→ ABR→ HSSF Wetland→ Irrigation / Discharge

ABR + HSSF wetland = zero electricity, no moving parts, 25-year design life. Lowest cost treatment for Pakistan conditions.

🌬️

High-Ammonia Streams

pH Adj.→ Ammonia Stripping→ UASB→ SBR→ Discharge

Ammonia stripping tower removes NH₃-N to <50 mg/L before biological stages. (NH₄)₂SO₄ fertiliser by-product recovered.