Comparison of effluent quality

The technical brief and the master thesis can be accessed with here.

A technical brief of the comparison system can be found here.

The master thesis underlying this comparison system was supported by the German Red Cross and the International Federation of Red Cross and Red Crescent Societies. The master thesis was conducted during the Cox’s Bazar People Movement Operation of the International Federation of Red Cross and Red Crescent Societies.

The high number of different faecal sludge treatment plants, reportedly up to 500, in the Kutupalong mega camp made an easily understandable comparison system necessary to better understand the public and environmental health impact of the treatment plant effluent.

The comparison system presented here was developed as part of a master thesis (Orlob, 2019). The aim of the thesis was to develop a simple comparison system which will provide a single value (system score) for an easy comparison of the effluents of field faecal sludge treatment plants. For the calibration of the system the effluent of a limited number of treatment plants located in the Kutupalong-Balukali mega camp, Bangladesh operated by different humanitarian aid organisations was sampled and analysed.

Calculation of the System Score

The system score is used to for the comparison of the environmental and public health impact of (liquid) effluents of field faecal sludge treatments plants. For the calculation of the system score the analysis of four parameters is needed:

  • Chemical oxygen demand (COD)
  • Ammonia-Nitrogen
  • Coliform colony forming units (CFU)
  • Helminth eggs
Tables and formulas needed for the calculation of the system score

Attention: While the system score can be calculated from the analytical results of a single sample, it is advised to average the analytical results over a longer time period to better represent the plant effluent.

Comparison with regulations

Next to the comparison of treatment plants to each other, the system can also be used to compare a treatment plant with national standards and regulations. The effluent thresholds of the four parameters are used for the calculation of the comparative value.

Attention: A treatment plant with a lower comparative value than the regulations does not automatically imply concordance with those regulation and standards. E.g. better than required COD removal may balance an exceeding Coliform CFU concentration, while still resulting in a comparative value lower than the regulations.