A leachate study was conducted at the Etueffont landfill (Belfort, France), to examine differences in leachate composition between old and new areas of the fill and their seasonal evolution. It was based on hourly (1999), monthly (1998-1999) and annual (1993 to 1998) samplings of domestic landfill leachate. Variations in flow rate, rainfall, temperature, electrical conductivity, O2, pH, Cl, SO4, Zn, Cu, Fe, Ni, HCO3, NO3, NH4, BOD and COD were monitored. The results from monthly samplings showed close coupling between flow and concentrations of all parameters measured in the leachate. Indeed, these latter parameters decreased with increasing flow rates. Also, mass emissions per unit waste mass decreased with increasing waste age. The hourly monitoring pointed out an increase in electrical conductivity, chloride and COD concentrations in the middle of the day. This was most likely attributable to temperature fluctuations.

To evaluate the landfill leachate impact on the stream water quality, we assessed the spatial evolution of several abiotic and biotic parameters in Etueffont domestic landfill (Belfort, France). The samples were taken in 13 June 1999 with a Van-Dorn bottle from upstream to downstream. The study showed that leachate rejection resulted in an increase of the pH, NO 3 -, Cl -and COD concentrations in the first meters after rejection. In downstream, however the reverse was quoted. Bacterial abundance increased from upstream to downstream with no relationship between this biological compartment and leachate rejection. Finally, it seems likely that the abilities of self regulation of brook were higher to the leachate-induced pollution.

Dans le cadre d'un traitement par lagunage naturel des lixiviats d'une décharge d'ordures ménagères broyées, nous avons procédé au cours d'un cycle annuel (mai 1998 à mai 1999) à des analyses biologiques et physicochimiques des eaux à l'entrée (lixiviat brut), dans les quatre bassins successifs et à la sortie du dispositif (lixiviat traité) avant son rejet dans le milieu récepteur (ruisseau Mont Bonnet). L'évolution spatiotemporelle de la qualité des lixiviats a été approchée par le suivi des fluctuations saisonnières de divers paramètres (température, conductivité électrique, pH, oxygène dissous, potentiel redox, chlorures, fer, manganèse, nickel, zinc, azote total, phosphore total, ammonium, DBO, DCO et chlorophylle a). Les résultats montrent deux périodes de dysfonctionnement de la station durant l'année. Un dysfonctionnement estival marqué par une chute du rendement épuratoire du fer, du manganèse et de la DBO, sous l'effet d'une diminution du potentiel redox et du surplus de matières organiques autochtones. Le deuxième dysfonctionnement, observé en hiver et au début du printemps, est caractérisé par une chute des rendements épuratoires pour l'ensemble des éléments chimiques suivis. Cette chute des rendements épuratoires est vraisemblablement liée à la diminution importante des valeurs de pH durant cette période.

The quantitative distribution of dominant phytoplankton species was carried out in the stabilisation ponds of Etueffont landfill leachate (Belfort, France) from May 1998 to May 1999. The results showed maximum phytoplankton abundance in the last lagooning basin during summer 1998, that coincided with an increase in temperature and better leachate quality. In addition, the phytoplankton was dominated by Euglenophytes species Phacus sp. and Euglena sp. known to resist constraints induced by the highly polluted aquatic environments. An improve in water quality of the last basins translated into a shift in species composition with the substitution of the Bacillariophyceae (Stephanodiscus dubius) by the Chlorophyceae (Coelastrum sp.).

A study in the Etueffont landfill, located in Belfort (France), was conducted to evaluate the performance of combining natural lagooning and use of two sand filters for treating leachates through the coupling estimation of several abiotic and biotic parameters. Two gravel filters were installed in the upstream of the first basin which communicates with the remaing 2, 3 and 4 basins. The distribution of physical-chemical (T, pH, Eh, EC, O2, SM, SO4(2-), Cl-, Zn, Fe, Mg, Ni, Al, As, Ba, Cu, Sn, Zn, BOD, COD, KN, NH4+, NO2+ ,TP, AOX: absorbable organic halides, VFA: volatile fatty acids, and atrazine) and biological (bacteria, protozoa, phytoplankton) parameters was assessed in the leachate entering in basin 1, and downstream of the filters. The results showed slight variations in the physical-chemical composition of the leachate between 1999 and 2000, most likely ascribed to the maturation of the landfill but a very significant removal of SM (suspended matter) by the sand filters. This, applied to the majority of the studied parameters. Thus, the sand filter treatment of the leachates combined with natural lagooning was efficient in the improvement of water clarification.