Abstracts
Abstract
Wastewater conductivity has been monitored for extended periods of time by in situ probes and on grabbed samples in four communities (from 1,000 to 350,000 PE). In parallel, the concentrations of the main ionic contributors, such as calcium, sodium, potassium, magnesium, ammonium, ortho-phosphate, chloride and sulphate have been measured and their variations with respect to time compared to human activity patterns. It appears that sodium, potassium, ammonium and ortho-phosphate, which contribute to about 34% to wastewater conductivity, exhibit diurnal variations in phase with human activity evaluated by absorbance at 254 nm. However calcium (≈ 22% of wastewater conductivity) is out‑of-phase. This release, ahead of the one of other cations and anions, could be related to sewer concrete corrosion or to groundwater infiltration. The combination of these different ionic contributions creates a conductivity pattern which cannot be easily related to human activity. It makes difficult to integrate conductivity in a monitoring system able to detect ion-related abnormalities in wastewater quality.
Keywords:
- Conductivity,
- corrosion,
- urine,
- calcium,
- potassium,
- infiltration
Résumé
Les variations de la conductivité d’eaux usées urbaines ont été suivies sur de longues durées a l’aide de sondes placées in situ en entrée d’installations de traitement et sur des échantillons prélevés automatiquement. Quatre communautés (entre 1 000 et 350 000 habitants) ont été choisies pour cette étude. On a également dosé sur les échantillons les principaux ions (calcium, sodium, potassium, magnésium, ammonium, ortho-phosphates, chlorures et sulfates). Il apparait que le sodium, le potassium, l’ammonium et les ortho-phosphates contribuent pour 34 % a la conductivité des eaux usées et présentent des variations journalicres en phase avec la pollution carbonée soluble, estimée a partir de l’absorbance a 254 nm. Par contre, le calcium, qui contribue pour 22 % a la conductivité, présente un déphasage qui peut ztre du a son transport dans le réseau d’assainissement du fait de la corrosion des conduites en béton ou a des infiltrations d’eaux claires. Finalement, la combinaison de ces différentes contributions ioniques conduit a une variabilité de la conductivité qu’il n’est pas facile de lier a l’activité humaine, et donc a des rejets accidentels dans le cadre d’un systcme de détection de variation anormale de la qualité des eaux usées.
Mots clés:
- Conductivité,
- corrosion,
- urine,
- calcium,
- potassium,
- infiltration
Appendices
Références bibliographiques
- DE BELIE N., J. MONTENY, A. BEELDENS, E. VINCKE, D. VAN GEMERT and W. WERSTRAETE (2004). Experimental research and prediction of the effect of chemical and biogenic sulphuric acid on different types of commercially produced concrete sewer pipes. Cem. Concr. Res., 34, 2223-2236.
- BÖHM M., J. DEVINNY, F. JAHANI and G. ROSEN (1998). On a moving-boundary system modelling corrosion in sewer pipes. Appl. Math. Comput., 92, 247-269.
- EL SAMRANI A.G., B.S. LARTIGES, J. GHANBAJA, J. YVON and A. KOHLER (2004). Trace element carriers in combined sewer during dry and wet weather: an electron microscope investigation. Water Res., 38, 2063-2076.
- ERIKSSON E., K. AUFFARTH, M. HENZE and A. LEDIN (2002). Characteristics of grey wastewater. Urban Water, 4, 85–104.
- GRAPIN G. (2004). Wastewater quality: from continuous measurement to pollution alert. PhD thesis. National Polytechnical Institute of Lorraine, Nancy, France.
- HENZE M., P. HARREMOES, J. COUR JANSEN and E. ARVIN (2002). Wastewater treatment: biological and chemical processes, 3rd Ed. Springer, Heidelberg, 430 p.
- HERNANDEZ M., E.A. MARCHAND, D. ROBERTS and J. PECCIA (2002). In situ assessment of active Thiobacillus species in corroding concrete sewers using fluorescent RNA probes. Int. Biodeterior. Biodegrad., 49, 271-276.
- HOCHEDLINGER M., G. GRÜBER and H. KAINZ (2005). Assessment of spill flow emissions on the basis of measured precipitation and waste water data. Atmos. Res., 77, 74-87.
- KIM OANH N.T. and G.E. BENGTSSON (1995). Development of a wastewater monitoring program incorporated into process control for mitigation of chemical and fiber loss from the Bai Bang Paper Company (BAPACO), a bleached kraft pulp and paper mill in Vietnam. Resour. Conserv. Recycl., 14, 53-66.
- KREBS P., P. HOLZER, J.L. HUISMAN and W. RAUCH (1999). First flush of dissolved compounds. Water Sci. Technol., 39, 55-62.
- LANGERGRABER G., N. FLEISCHMANN and F. HOFSTÄDTER (2003). A multivariate calibration procedure for UV/VIS spectrometric quantification of organic matter and nitrate in wastewater. Water Sci. Technol., 47, 63-71.
- LE BONTE S., O. POTIER and M.N. PONS (2005). Toxic event detection by respirometry and adaptive principal components analysis, Environmetrics, 16, 1-13.
- METCALF and EDDY (1991). Wastewater engineering: Treatment, disposal and reuse. 3rd Edition, Mc-Graw-Hill, New York, USA.
- MRKVA M. (1983). Evaluation of correlations between absorbance at 254 nm and COD of river waters. Water Res., 17, 231-235.
- NIREL P.M.V. and R. REVACLIER (2003). Authentication of a physico-chemical variability index in freshwaters: relationship with biological quality. Aquat. Ecosys. Health Manage., 6, 1-5.
- PEDERSEN B., K. GERNAEY, M. HENZE and P.A. VANROLLEGHEM (2002). Evaluation for an ASM1 model calibration procedure on a municipal-industrial wastewater treatment plant. J. Hydroinform., 4, 15-38.
- ROBERTS D.J., D. NICA, G. ZUO and J.L. DAVIS (2002). Quantifying microbially induced deterioration of concrete: initial studies. Int. Biodeter. Biodegrad., 49, 227-234.
- SCHILPEROORT R.P.S., G. GRUBER, C.M.L. FLAMINK, F.H.L.R. CLEMENS and J.H.J.M. VAN DER GRAF (2006). Temperature and conductivity as control parameters for pollution-based real-time control. 5th IWA World Congress, Beijing, China,10-14 September 2006.
- THOMAS O., F. THERAULAZ, M. DOMEIZEL and C. MASSIANI (1993). UV spectral deconvolution: a valuable tool for wastewater quality monitoring. Environ. Technol., 14, 1187-1192.
- UDERT K.M, T.A. LARSEN and W. GUJER (2003a). Estimating the precipitation potential in urine-collecting systems. Water Res., 37, 2667-2677.
- UDERT K.M., T.A. LARSEN, M. BIEBOW and W. GUJER (2003b). Urea hydrolysis and precipitation dynamics in a urine-collecting system. Water Res., 37, 2571–2582.
- WU J., M.N. PONS and O. POTIER (2006). Wastewater fingerprinting by UV-visible and synchronous fluorescence spectroscopy, Water Sci. Technol., 53, 449-456.