"Bioreaktivt filter - Utprøving av bioreaktivt filter i fullskalaforsøk for rensing av avløpsvann fra utslipp av plantevernmiddelrester fra aske-/påfyllingsplasser"


Ole Martin Eklo
Bok Bokmål
Les boka på nett
Medvirkende
Omfang
43
Opplysninger
The aim of the project was to identify an optimal biofilter for collecting and purifying run-off water from areas for handling of pesticides and cleaning of spraying equipment. To achieve this, a biofilter system consisting of stackable cassettes filled with a mixture of soil (25%), compost (25%) and straw (50%), and a concrete slab (handling/cleaning site) with a water collection system, was constructed and tested under normal operating conditions at a potato and grain farm. The biofilter was tested for efficiency for reducing pesticide concentrations in water/runoff, capacity through several years of operation, and degradation and sorption of pesticides. The results show a good effect of reducing pesticide concentrations when circulating contaminated water through the biofilter. During the trial period, the biofilter was regularly supplied with washing water from the water collection tanks at the handling/cleaning site. There was a reduction of more than 95 % for many of the pesticides, and the lowest measured pesticide reduction was at around 70%. Challenges were related to pesticides used for potato tuber which were added in high concentrations. The capacity of the filter was deemed satisfactory. After 4 years of use, the biofilter is still very effective. However, our results show that there is a need for annual replenishment of biomix during the period of use. Degradation studies indicate a more rapid degradation of pesticides in the biomix as compared to agricultural soil. The biomix also provided a strong sorption for the tested pesticides. Biochar can further increase the sorption capacity for challenging substances. To ensure the capacity and efficiency of the biofilter, it is recommended that clean water be directed outside the water collection tank.
Emner
report
ISBN
9788217028543

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