Continuous Measurement of Ammonia in River Water

River water quality is assessed by the Environment Agency through the General Quality Assessment (GQA) programme and it is vital that potentially harmful chemicals in the river are controlled. Ammonia is an important nutrient for plants and algae that live in river water. However, when the river temperature changes, the ionized ammonia changes to non-ionized ammonia gas. This is deadly to fish and other aquatic life in the river, so it is important to constantly monitor ammonia levels.

Water quality is also important for water treatment plants that use river water as their source. High levels of ammonia in the water can cause major problems for the disinfection process. By successfully measuring ammonia levels in river water at the inlet of a water treatment plant, the organization is able to protect the inlet supply. In some applications, the inlet can be closed when ammonia levels reach unacceptably high levels.

Current ammonia monitoring techniques are expensive and complex, use ion-selective electrodes and expensive reagents, are toxic and difficult to handle. These monitors are also non-specific and require continuous calibration to adapt to different needs, such as wastewater treatment, drinking water treatment and measuring ammonia levels in river water. Ion-selective electrodes typically require daily zeroing and calibration with reagents.

The HONDE ammonia monitor avoids the challenges of traditional ammonia monitors by using a completely unique approach. The ammonia is converted to a stable monochloramine compound at a concentration equivalent to the original ammonia level. The chloramine concentration was then measured using a polarographic membrane sensor with a selective linear response to chloramine. Reaction chemistry gives the monitor excellent sensitivity even at very low (ppb) ammonia levels.

The reagent is simple, low price and low utilization rate. So the cost of ownership is very low.

The larger UK water companies and some Environment Agence-accredited laboratories are already using HONDE monitors to effectively monitor ammonia levels in river water. This new ammonia system from Analytica Technologies provides users with a monitor that is simple to operate, economical to purchase, low to run and free from measurement interference.