About Sludge and Biosolids
Wastewater Sludge
Wastewater treatment facilities collect waste from residential, commercial, and industrial sources. The plants must treat the wastewater to meet safety standards before release or disposal.
Plants separate the liquids and solids during treatment, and the resulting slurry of solids is known as
"sludge."
Microorganisms are used to digest the materials, yielding a sludge that is largely made of the cells of these miniature cleaning crews. Sludge also contains pathogens that could threaten public health.
Biosolids
While some water treatment plants simply make the sludge safe enough to dispose of,
most facilities continue treatment so that the material can be put to good use in their
communities.
Once sludge is treated to meet EPA safety standards for beneficial use, the resulting nutrient-rich product is termed "biosolids." These biosolids are used to enrich soil and reduce the need for harsh chemical fertilizers. There are three types of biosolids:
There are three types of biosolids:
Dried Biosolids
Fenton dryers produce Class A and Class A EQ biosolids by heat-treating sludge until
the water evaporates and the pathogens are killed. The dark granules produced by the
Fenix™ provide a slow release of nutrients to plants. Dried biosolids have proven to be an effective
and easy-to-use fertilizer for farms, ranches, parks, golf courses, wild lands, and home
gardens. To learn more about biosolids and waste regulations visit our links and resources area.
The Granular Advantage
Dried biosolids come in either a pellet or granular form. Fenton has chosen to produce granular
biosolids for several reasons:
- Granular systems are more compact
- Pellet systems have more mechanical points where systems can fail
- Granular biosolids are a consistent product that works better as a soil amendment
The larger size of biosolids pellets means a very slow breakdown period and a tendency to wash away with heavy rainfall, sometimes wreaking havoc with nearby lakes and rivers. Granular biosolids contain particles of various sizes which allows more thorough ground cover that sticks to the soil well. The smaller particles dissolve and deliver nutrients to plants quickly, while the larger ones break down gradually, supporting plants over a period of time.
Producing pelletized biosolids is a complex process involving sifting and reworking of the material until it reaches a desired size. This requires operator attention and often results in pellets that are over-dried and have a "burnt" odor.
When it comes to product acceptance, granular biosolids have a familiar soil amendment appearance that appeals to home users and farmers alike. The small size also allows municipalities to market custom soil mixes, because it is easy to combine Fenix™ biosolids with other soils and fertilizers.
