Phase 1 condition 2
Removal Efficiency (%) 2nd Condition Ozone
Average Removal end of condition 2
- 3 samplings in october 2019
- 30 compounds analysed
- 20/30 removal efficiency calculable
- Rest never above detection level or not fullfilling the removal rate calculation demands
Average removal
65% by biology
79% after first point ozonation
86% after multiple point ozonation
Removal efficiency after ozonation condition 1 (june ‘19). In the reference line some micropollutants are removed better than others and this corresponds with the findings from the autum ’18 and gives an average removal of 63%. In the experimental line with 2 times ozone injection a whole other picture is seen. After just one point of ozonation an average removal of 78% was observed and after injecting ozone a second time (tertiary) it reached 93% removal in average!
Micropollutant concentration vs. PNEC
Above PNEC end of condition 1
- 3 samplings in october 2019
- 36 compounds investigated
- 5 > PNEC in inlet wastewater
3 > PNEC after conventional biology
0 > PNEC after multiple point ozonation
After the first condition of ozone its clear to see the improvement. In the reference line 5/36 compounds were above PNEC in the outlet. However, after multiple point ozonaton none of these 5 micropollutants is even detectable in the waterphase anymore. In fact, 32/26 came below limit of detection (LOQ).
Only 3 are above in the reference line, but not far above PNECs -> could be due to a lot of water to the plant in October 2019 (approx. 200.000 m3) comparred to october 2018 (60.000m3)
Sludge Volume Improvement
Mixed-liquor ozonation can effectively reduce sludge volume
