pH Control In Water Treatment

pH control plays a crucial role in water treatment processes across various industries. It ensures wastewater meets environmental standards, protects infrastructure, and enhances the efficiency of other water treatment methods.

Whether for industrial effluent, swimming pools, or drinking water, controlling pH levels is essential for regulatory compliance and environmental responsibility.

Want better pH control in your wastewater treatment system? Get in touch with Trade Environmental. We’ve worked with businesses in dozens of industries, and know what it takes to create a functional system that performs well into the future.

What is pH?

pH measures the acidity or alkalinity of a substance on a scale from 0 to 14. A pH of 7 is neutral, while values below 7 indicate acidity, and those above 7 signify alkalinity.

For example:

• Acidic substances: Lemon juice (pH ~2), vinegar (pH ~3)
• Neutral substances: Pure water (pH 7)
• Alkaline substances: Baking soda (pH ~9), bleach (pH ~12)

Maintaining a specific pH range in water is vital for industrial processes, environmental safety, and public health. For instance, trade waste authorities typically require wastewater discharge to have a pH between 6 and 10.

Furthermore, when recycling water, a neutral pH is crucial for other forms of treatment such as filtration and dosing to work effectively.

The Process of pH Control

pH control involves adjusting the alkalinity or acidity of water by adding chemicals. This makes certain that the liquid’s pH stays within the desired range, preventing environmental harm and ensuring compliance with discharge regulations.

A pH control system typically includes three main components:

1. Probe: Measures the current pH of the water.
2. Controller: Determines the necessary correction and activates the chemical injection system.
3. Injection pump: Adds acidic or alkaline substances to the water to achieve the desired pH.

Types of pH Control Systems

There are two common types of pH control systems:

• In-line pH control: A probe measures pH directly in the pipe or tank, and chemicals are injected into the flow.
• Recirculating pH control: Water is pumped from a tank to a measurement system, where it is treated and returned. This method provides greater accuracy, as the system constantly monitors circulating water and reduces wear on sensitive probes.

Applications of pH Control in Water Treatment

pH control has widespread applications across industries. It is critical for wastewater treatment, industrial processes, and even recreational facilities.

1. Effluent treatment: In industries like mining and manufacturing, wastewater often contains pollutants that can harm the environment if discharged untreated. pH control neutralises the water, ensuring it meets regulatory standards. In some cases, pH adjustment enhances other treatment processes, such as coagulation, where chemicals bind suspended solids for easier removal.
2. Industrial operations: Car washes, workshops, and service stations generate wastewater with oils, chemicals, or greases. pH control prevents damage to plumbing systems and ensures safe discharge. Mining operations use pH adjustment to neutralise acidic runoff, protecting surrounding ecosystems.
3. Recreational and public facilities: Swimming pools require a pH around 7.4 to prevent skin irritation and cloudy water. Drinking water must have a pH within 6.5 to 8.5 for safety and palatability.

Common Chemicals Used in pH Control

To adjust pH levels, different chemicals are used depending on the treatment requirements:

• Sodium hydroxide: Increases pH in acidic water.
• Hydrochloric acid: Decreases pH in alkaline water.

These chemicals are dosed in precise quantities to achieve the desired pH range without over-correction.

Benefits of pH Control

While every business wants to avoid fines and meet discharge standards, there are many benefits to pH control that extend beyond regulatory compliance:

• Enhanced treatment efficiency: Optimise processes like coagulation and sedimentation.
• Infrastructure protection: Prevent corrosion or scaling in pipes and equipment.
• Public safety: Ensure safe and clean water for public use, whether in swimming pools or drinking supplies.

Beyond compliance, pH control is vital for protecting the environment. For instance, improperly treated acidic water can damage aquatic ecosystems, while alkaline water can disrupt soil and plant health.

By maintaining appropriate pH levels, industries contribute to sustainability while safeguarding public resources.

Challenges in pH Control

While pH control is highly effective, improper setup or maintenance can lead to inefficiencies:

• Incorrect chemical dosing can result in over-correction, wasting resources and harming equipment.
• Neglecting to clean or calibrate probes can cause inaccurate readings, leading to poor pH control.
• Regular maintenance and expert advice are key to overcoming these challenges.

How Trade Environmental Can Help

Paul Banner, Trade Environmental’s Managing Director, has been working with businesses for years:

“pH control is one of the most integral parts of water treatment. We’ve worked with everyone from industrial operations to public facilities, helping them manage pH levels for compliance, operational efficiency, and environmental sustainability.”

If you’re looking for expert guidance or high-quality pH control systems, Trade Environmental offers tailored solutions for every industry. Contact us today to find the perfect system for your business and ensure your water treatment processes meet the highest standards.