The European Community has decided in 1991 to oblige all EU Member States to be equipped with wastewater treatment plants for all cities whose wastewater organic load is greater than 15000 equivalent-inhabitants (to be implemented before the 31st December 2000) and 2000 equivalent-inhabitants (to be implemented before the 31st December 2005). The characterisation of wastewater at the inlet and outlet of the treatment plants is an effective way to control the process efficiency and to verify the final quality of treated waters. Usually, wastewater quality is characterised both by global parameters like Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Organic Carbon (TOC) or Total Suspended Solids (TSS), and by nitrogen and phosphorous compounds. All values must be lower than maximum permissible values, depending on specific regulations. These dispositions are of great importance but unfortunately monitoring procedures presently performed are not very satisfying because they involve sampling, storage and laboratory analysis, a succession of sample handlings which considerably enhance the risks of errors. There is an increasing need now to limit sample handlings and to develop fast and accurate devices enabling to monitor a range of parameters by direct field-measurements.
The aim of this study was to develop a simple wastewater quality monitor based on spectrophotometric methods for the measurement of BOD, COD, TOC, TSS, global N and total P. Other parameters such as nitrate, nitrite, ammonium, orthophosphate or detergents can be directly measured with the system.
The prototype device has been successfully tested and is now available on the market. The results of the experiments and development phase are fully described in the Report EUR 16914 EN (1996).
The proposed multiparametric monitor was built around a Sequential Injection Analysis (SIA) system coupled with two simple spectrophotometric detectors. All parameters are measured using one of the two following principles. The first one is based on the direct exploitation of the UV spectrum of the sample and the second principle involves a chemical reaction with one stable and simple reagent.
Funding SchemeCSC - Cost-sharing contracts
07071 Palma De Mallorca