Alternatives to the Ceres process are very limited in the “stabilization” category however there are alternatives to “dispose” of the organic waste including incineration, land application, composting, and anaerobic digestion.
Incineration is the reduction of a large mass of organic waste to a smaller mass that is then landfilled. Generally this option is now being eliminated due to the uncertain impact on air quality and local residents’ objection.
Land application of either liquid or solid applications is used for bisosolids only and this material is land applied under generally local government regulation that strictly controls the time and volume of application. This option is rapidly becoming more restrictive and regulated.Local government control of this activity is limited in Asia but is growing due to local watershed concerns and the public health issue associated with farmers handling untreated material.
Composting is the conversion of all organic wastes into a soil bulk additive with limited N-P-K nutrient value. Composting requires the use of a carbon source (usually wood chips) in order to achieve proper composting. The process produces foul odours, and because of this, composting sites are subject to local regulation. Composting guidelines may also limit the amount of biosoldis that can be used in a composting operation.
Anerobic Digestion (“AD”) is typically applied in conjunction with some form of energy recovery and resulting in a “digestate” which is also an organic material that ultimately needs disposal. AD is also used for most “on-farm” organic waste management. Large scale AD systems are rare as they are highly susceptible to disruption if the quality of the inbound material varies too much.AD is used in Surat, India to produce electricity for internal STP consumption.
Stabilization typically involves the application of a chemical or other additive to achieve pathogen kill and, in some cases, a dryer final product. While there are other technologies that offer an alternative to the Ceres System none have achieved the scale of operation of Ceres.