Ecological equilibrium on biological activated carbon

Scholz, M; Martin, R

Abstract

This paper examines the potential of a biological activity control system (BACS) for biological
activated carbon (BAC) in comparison to granular activated carbon (GAC) for the treatment of potable
water. The overall objective of the project is to produce drinking water of a higher quality more
economically by developing a BACS for exhausted GAC that can be transformed to BAC by the
development of a natural biofilm during the bio-regeneration mode. The research therefore may be
interesting for water companies and the activated carbon industry. Findings show that the lifetime of a
GAC filter can be significantly extended by maintaining an active biofilm that has to be controlled in order
to avoid filter clogging. The most important parameters are dissolved oxygen (DO), pH and a correct
balance of nutrients, which enables a natural control of the biomass, pH control was required to maintain
an optimal bacteria-protozoa level. Excessive growth of filamentous bacteria can be prevented by a
decrease in I-)O, increase in pH and the reduction of one essential nutrient, e.g. total phosphorus (P). Total
organic carbon (TOC) and chemical oxygen demand (COD) values were reduced by bioactivity. DO,
turbidity anti suspended solids (SS) values were kept in acceptable ranges with respect to drinking water
objectives. Plants without a significant population of protozoa deliver turbid low quality effluent high on
SS and biochemical oxygen demand (BOD). It was possible to control the biofilm on GAC containing
a natural biofilm and BAC during the bio-regeneration mode. Natural and artificial bio-regeneration lead
to similar performance characteristics.

Citation

Scholz, M., & Martin, R. (1997). Ecological equilibrium on biological activated carbon. Water Research, 31(12), 2959-2968. https://doi.org/10.1016/S0043-1354%2897%2900155-3

• Journal Article Type: Article
• Publication Date: Jan 1, 1997
• Deposit Date: Jul 15, 2011
• Journal: Water Research
• Print ISSN: 0043-1354
• Publisher: IWA Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 31
• Issue: 12
• Pages: 2959-2968
• DOI: https://doi.org/10.1016/S0043-1354%2897%2900155-3
• Keywords: GAC, BAC, comparison between GAC and BAC systems, biological regeneration, biofilm development, pH/DO control, protozoa-bacteria equilibrium, organic carbon removal, phosphorus removal
• Publisher URL: http://dx.doi.org/doi:10.1016/S0043-1354(97)00155-3