Biotransformation of aromatic hydrocarbons in subsurface biofilms, W. Zhang et al; elimination of p-chlorophenol in biofilm reactors - a comparative study of continuous flow and sequenced batch operation, H.-P. Kaballo et al; modelling biofilm biodegradation requiring cosubstrates - the quinoline example, M.J. Malmstead et al; modelling of volatile organic contaminants in trickling filter systems, H. Melcer et al; effects of biofilm structure, microbial distributions and mass transport on biodegradation processes, P.L. Bishop et al; experimental and conceptual studies on mass transport in biofilms, Z. Lewandowski et al; anoxic and oxic biological fluidized bed treatment of amines and phenol, V.T. Nguyen and W.K. Shieh; cometabolism in biofilm reactors, G.E. Speitel Jr. and R.L. Segar Jr.; development and application of bacterial cultures for the removal of chlorinated aliphatics, D.B. Janssen and W. De Koning; use of ribosomal RNA-based molecular probes for characterization of complex microbial communities in anaerobic biofilms, L. Raskin et al.