Biofilter trials delayed

Press, 16 May 1985, Page 5

Biofilter trials delayed

Wet weather this week has held up the results of the Christchurch Drainage Board’s experiments with the new biofilter to combat odorous air.

The results of the experiments at the board’s sew-age-treatment works could be available by June, the chief engineer, Mr H. P. Hunt, told the operations and services committee yesterday. “While the wet weather affects the experimental work it will not affect the final biofilter that we build,” he said. “In fact, we will need to spray the material that we choose to ensure that it stays wet.”

Three containers of material were being tested, Mr Hunt said in his report. “One container holds peat and manuka; another holds peat, wood, and bark chips; the third contains peat and bark chips. Various odorous air flow rates and other operational conditions are under investigation on the three containers. “A manifold is necessary to ensure even air distribution through the filter media under all weather conditions.” Biogas Advertising of excess biogas by the board could have been misleading, said the finance committee’s chair-

man, Mr R. B. Wright. Mr Wright was questioning the committee’s ability to fulfil obligations if a market for bulk biogas is found. Mr C. H. Russell said the advertising was only to find out how much interest there was among local bodies and the public in converting to biogas. The conversion would not be as easy for diesel-driven engines as for the Drainage Board’s petrol-powered vehicles, he said. Mr Russell said he had also decided to test the market now because in the past it had taken up to two years to get a response.