Modeling a pilot-scale bio-geo-filter for removing soluble nitrate

This study uses alternate layers of non-woven geotextile and granular soil to remove soluble nitrate. The mixing weight ratios of PRB materials are 25% sand, 25% anthracite, 20% zeolite, 20% iron filings, and 10% poplar sawdust. Synthetic wastewater with an initial nitrate concentration of 100 mg/l is introduced to the filter over 25 minutes of the filter breakthrough curve (BTC). The BTC from the column test is assumed as a normal curve and the obtained longitudinal dispersion coefficient is equal to 1×10 − 7 m 2 /s. The filter reduces the amount of nitrate by 99% within nine days. CTRAN/W software properly estimates the contaminant transport in the filter. However, the BTC obtained by the software cannot estimate the total time for a complete breakthrough under laboratory conditions. At the same time, it can determine the nitrate breakthrough time close to the experimental model.