Submitted to: Water Environment Federation
Publication Type: Abstract only
Publication Acceptance Date: 3/25/2003
Publication Date: 11/1/2003
Citation: Lima, I.M., Marshall, W.E., Fitzmorris, K.B., Reimers, R.S. 2003. Animal biosolids as granular activated carbons for environmental remediation (abstract). Water Environment Federation. Interpretive Summary: The objective of this work was to study the potential application of granular activated carbons prepared from chicken litter for the removal of environmental pollutants. The conversion of animal waste to activated carbons and their use for removal of pollutants from air and water represents a novel approach to the utilization of this waste. This can provide a profitable alternative to the current disposal of animal manures deriving from concentrated animal facilities. These carbons displayed excellent physical/chemical and adsorptive properties, superior to some available commercial carbons. This research will benefit poultry producers as the poultry litter will now have additional value through its conversion into a value added product, namely activated carbon.
Technical Abstract: Water quality and public health impacts of animal manure produced at large concentrated animal facilities prompted the need for viable solutions for their conversion and reuse. Current approaches to dispose of raw manure such as lagoon storage, anaerobic digestion and composting or transformation into soil additives and amenders can still pose associated health and environmental risks and produce low value alternatives. The conversion of animal biosolids to value added products, such as activated carbons for environmental remediation, could be a profitable alternative. The Southern Regional Research Center (SRRC) has conducted experiments on the feasibility of converting pelletized poultry biosolids to activated carbon. The process involved pyrolyzing a pelletized sample of poultry biosolids (stabilized/disinfected manure plus wood chips as a binder) under nitrogen at 700°C for one hour, followed by steam activation at 800°C under nitrogen for a period ranging from 1 to 4 hours. Specific physical and adsorptive properties of this steam-activated carbon were determined and compared to a steam activated commercial coal-based carbon (Filtrasorb 400). Physical properties (yield and surface area) and adsorptive properties (organics adsorption) of the biosolids-based carbon were lower than the reference carbon. Yet, the carbon produced from animal biosolids was superior in metal ion uptake. This was the case for copper ion where 0.40 mmoles of Cu2+ per g carbon was adsorbed by our carbon compared to 0.17 mmoles/g for Filtrasorb 400). Copper is one of the metals of particular environmental concern because it is toxic to many animal species and because of its ubiquitous presence in the environment. Since our studies have been preliminary, we anticipate further improvements in both physical and adsorptive properties of our biosolids-based carbons by varying pyrolysis and activation conditions as well as binder type and biosolids to binder ratios. We believe the conversion of animal biosolids to activated carbons and their use for remediation of polluted air and water media represents a novel approach to the utilization of animal biosolids.