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Water Treatment

Alkali Dosing Systems

Caustic soda, soda ash, and potassium hydroxide dosing for low-pH correction. Precision metering with real-time pH feedback control for any flow rate.

Caustic, Soda Ash & Lime

Caustic Soda (NaOH)

Sodium hydroxide (25-50% solution) provides rapid pH increase. Most common alkali for industrial effluent. Instant reaction, precise control.

25-50% conc. 10-500 mg/L dose

Soda Ash (Na4CO3)

Sodium carbonate for moderate pH increase with alkalinity addition. Safer handling than caustic. Ideal for boiler feed and cooling water.

Powder/soln. 20-300 mg/L dose

Hydrated Lime (Ca(OH)4)

Calcium hydroxide slurry for bulk pH raise at lowest cost per kg alkalinity. Common in mining, steel, and municipal applications.

15-30% slurry 50-2,000 mg/L dose

Quicklime (CaO)

Calcium oxide for large-scale neutralisation. Requires slaking to Ca(OH)4 before dosing. Lowest chemical requirement for high-tonnage operations.

Bulk powder 20-5,000 kg/hr

Where Alkali Dosing Is Used

Low pH Effluent

Process Water

AMD Treatment

Metals Precipitation

pH Compliance

Coagulation Aid

Alkali Dosing Equipment

Peristaltic Pumps

Gentle pumping action for caustic soda without seal wear. Self-priming and dry-run capable.

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pH Controllers

Dual-setpoint controllers for alkali dosing with deadband to prevent acid-alkali hunting.

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Lime Slurry Systems

Automated lime preparation with mixing tanks, recirculation loops, and progressive cavity feed pumps.

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Agitators

Tank mixers for lime slurry suspension and caustic solution homogenization.

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Process Fundamentals

pH correction is a critical stage in wastewater and process water treatment. Incorrect pH can damage downstream biological systems, corrode pipework, violate discharge consent limits, and compromise product quality. Our dosing systems utilise flow-proportional control with automated feedback loops to maintain target pH within ±0.2 units, regardless of influent variability.

Neutralisation Kinetics

Rapid mixing and reaction kinetics ensure complete neutralisation before downstream processes.

Dose Control

Flow-paced and feedback-controlled dosing eliminates chemical wastage and overshoot.

Buffer Capacity

Systems account for influent buffer capacity to calculate precise reagent requirements.

Temperature Compensation

Automated temperature compensation ensures accurate pH measurement across seasonal variations.

Design Parameters & Sizing

Flow Range0.5 – 5,000 m³/h
pH Setpoint Range4.0 – 10.5 (adjustable)
Control Accuracy±0.2 pH units
Response Time<30 seconds to setpoint
Reagent Concentration10% – 98% (application specific)
MaterialsSS316L, PVC, PVDF, PTFE, rubber-lined steel
Control PhilosophyFlow-paced + cascade PID feedback
CommunicationModbus RTU/TCP, Ethernet/IP, OPC-UA

Compliance & Standards

ISO 9001:2015

Quality management systems ensuring consistent design, manufacture, and commissioning.

ATEX / IECEx

Explosion-proof dosing skids available for Zone 1 and Zone 2 hazardous area installations.

Environmental Permits

Systems engineered to meet local discharge consent limits including pH, metals, and COD.

Related Pages & Equipment

pH Correction Overview

Complete pH neutralisation systems for acid and alkaline wastewaters.

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Acid Dosing

Sulphuric, hydrochloric, and citric acid dosing systems.

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Alkali Dosing

Caustic soda, lime, and soda ash dosing for pH elevation.

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Lime Dosing

Slaked lime and quicklime systems for large-flow neutralisation.

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CO2 Dosing

Carbon dioxide re-carbonation for precise pH reduction without salt addition.

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Chemical Dosing

Complete reagent storage, preparation, and metering systems.

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pH Controllers

Automated pH controllers with dual-setpoint and alarm management.

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Dosing Pumps

PTFE diaphragm metering pumps for aggressive chemicals.

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Need pH correction for your process?

Contact Our Engineers for system design, sizing, and quotation.

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.