Removal of virus particles, bacteria and bovine serum albumin from water by steam-exploded Pinus radiata bark

Novel methods for removal of bacteria, viruses and high BOD material, such as proteins, from industry wastes and sewage, are of increasing interest particularly if they are able to harness waste materials from other industries. The washed, tannin-rich, material resulting from Pinus radiata bark treated by steam-explosion, has been investigated as a potential filtration medium for removing microorganisms and protein contaminants from water and waste water. The steam-exploded bark effectively removed a test virus (bacteriophage MS2) from dechlorinated tap water when used as a filtration medium (>99.9%) or when stirred in suspension (99% within 10 min). Bacterial species (Escherichia coli and Enterococci faecalis) in the same experiments were removed well by filtration (>99.9%) but stirring in bark suspension only reduced the initial titre by 55–62% within 10 min. Treatment of bovine serum albumin (100 mg/l and 700 mg/l) with steam-exploded bark in suspension removed up to 95% of the protein from solution. These results suggest that tannin rich steam-exploded bark products may have some application in treatment of protein rich effluents and those containing microbial contaminants.