Division 56
United Kingdom
BAT for pretreated waste water from the coking process and coke oven gas (COG) cleaning is to use biological waste water treatment with integrated denitrification/nitrification stages.
The BAT-associated emission levels, based on a qualified random sample or a 24-hour composite sample and referring only to single coke oven water treatment plants, are:
| In some cases, TOC is measured instead of COD (in order to avoid HgCl2 used in the analysis for COD). The correlation between COD and TOC should be elaborated for each coke oven plant case by case. The COD/TOC ratio may vary approximately between two and four. | |
| This level is based on the use of the DIN 38405 D 27 or any other national or international standard that ensures the provision of data of an equivalent scientific quality. | |
| This level is based on the use of the DIN 38405 D 13-2 or any other national or international standard that ensures the provision of data of an equivalent scientific quality. | |
| — chemical oxygen demand (CODf1) | < 220 mg/l |
| — biological oxygen demand for 5 days (BOD5) | < 20 mg/l |
| — sulphides, easily releasedf2 | < 0,1 mg/l |
| — thiocyanate (SCN-) | < 4 mg/l |
| — cyanide (CN-), easily releasedf3 | < 0,1 mg/l |
| — polycyclic aromatic hydrocarbons (PAH) (sum of Fluoranthene, Benzo[b]fluoranthene, Benzo[k]fluoranthene, Benzo[a]pyrene, Indeno[1,2,3-cd]pyrene and Benzo[g,h,i]perylene) | < 0,05 mg/l |
| — phenols | < 0,5 mg/l |
| — sum of ammonia-nitrogen (NH4 +-N), nitrate-nitrogen (NO3 --N) and nitrite-nitrogen (NO2 --N) | < 15 – 50 mg/l. |
Regarding the sum of ammonia-nitrogen (NH4 +-N), nitrate-nitrogen (NO3 --N) and nitrite-nitrogen (NO2 --N), values of < 35 mg/l are usually associated with the application of advanced biological waste water treatment plants with predenitrification/nitrification and post-denitrification.
Annotations
Footnotes
- f1
-
In some cases, TOC is measured instead of COD (in order to avoid HgCl2 used in the analysis for COD). The correlation between COD and TOC should be elaborated for each coke oven plant case by case. The COD/TOC ratio may vary approximately between two and four.
- f2
-
This level is based on the use of the DIN 38405 D 27 or any other national or international standard that ensures the provision of data of an equivalent scientific quality.
- f3
-
This level is based on the use of the DIN 38405 D 13-2 or any other national or international standard that ensures the provision of data of an equivalent scientific quality.