Bristle Worms

Identification

• Have bristles along their body
• Segmented bodies
• Their heads normally have two-to-four pairs of eyes

Why Do I Have It?

• Found in very old sludge
• Low F:M conditions
• Low ammonia levels

Treatment

If bristle worms are a known problem within a wastewater plant, adding AQUABACxt can help control their population. If you are concerned about your plant conditions contact a technical rep for information and recommendations.

Under the Microscope and in Your Plant

Bristle worms are found in very old sludge age and prefer high MLSS and low F:M conditions. Bristle worms can be large enough to be seen with the naked eye; they typically range from 300 µm to 1 cm. Bristle worms have been known to reduce MLSS levels by consuming bacteria. They appear to also have a tendency to consume the younger and healthier bacteria, which exacerbates the high sludge age-related issues. In lab studies using common wastewater food sources, Aquafix has noticed that the addition of dog food generated an increase in the bristle worm population.

Aeleosoma, or bristle worms, are a segmented worm that are easily identified by the bristles along their body. They have cilia that can create a vacuum, allowing them to feed on bacteria, algae, and other protozoa. Larger bristle worms can appear similar to tubifex worms when observed macroscopically, as they are similar in color.

Unique Experience in the Field

A common issue for wastewater plants during the winter months is an elevation of ammonia levels. A wastewater plant with bristle worms in their trickling filters has been known to frequently experience this issue. One year, this plant’s ammonia levels became too difficult to control which resulted in an effluent violation. It wasn’t just the cold weather that was responsible for their violation though. Bristle worms are sensitive to ammonia. So when the cold caused an increase of ammonia within their system, the bristle worms started to die. When bristle worms die, they release ammonia. Subsequently, this plant formed a cycle of continuous bristle worm death and increased ammonia levels. However, once their trickling filters were treated to remove the bristle worms, the plant’s ammonia effluent levels were able to return to normal and were no longer in violation.

Interesting Facts

• Are capable of distinguishing light from dark but some species have large eyes with lenses that may be able to see more
• Can regenerate injured or missing parts of themselves