title: Nutrient Limitation in a Compost Biofilter Degrading Hexane.
abstract: A laboratory-scale compost-based biofilter was operated over a six-month period to study the requirements for removal of n-hexane from air. Hexane is a relatively short chain aliphatic hydrocarbon with a high Henry's coefficient and a low water solubility. Acclimation of the biofilter was slow, but removal efficiencies around 80% were achieved after one month of operation. However, performance decreased during the next two months of operation to 50% removal efficiency. Nutrient limitation was proposed as a reason for the decrease in reactor performance. After the addition of a concentrated nitrogen solution, reactor performance increased almost immediately to >99%. Removal efficiency remained above 99% for the following two months of operation at inlet concentrations of 0.7 g/m3 (200 ppmv), at superficial bed velocities approaching 50 m/h, and empty bed residence times of about one minute. Thus, nutrient availability may well limit biofilter performance even in compost- based units. It was shown that nutrients can be added effectively in a soluble form if compost quality is poor and a method is proposed for the evaluation of compost quality.
authors.affiliation: a Institute for Water Quality Control and Waste Management, Technical University Munich , Garching , Germany.
authors.forename: Eberhard
authors.initials: E
authors.lastname: Morgenroth
authors.forename: Edward D
authors.initials: ED
authors.lastname: Schroeder
authors.affiliation: b Department of Civil and Environmental Engineering , University of California , Davis , California.
authors.forename: Daniel P Y
authors.initials: DP
authors.lastname: Chang
authors.affiliation: c Department of Land Air and Water Resources , University of California , Davis , California.
authors.forename: Kate M
authors.initials: KM
authors.lastname: Scow