Comparisons of Packing Materials in On-Site Wastewater Treatment System

Abstract

Numerous biological, physical and chemical parameters are involved in retention and removal of chemical pollutant and bacteria in wastewater treatment systems. Biofilm presence was often cited for its influence in these mechanisms. Sandy soil is the most used packing material in wastewater treatment study and little information is available for the other soil. The objectives of this study were to compare purification efficiency of packing materials (soil) and to allow a better understanding in purification mechanisms in one-site wastewater treatment. Our work focused on water pollution removal and biofilm development. For this purpose, four experimental reactors were packed with sand and silt suitable for on-site wastewater treatment plant. They were dosed with septic effluent at loads of 5 and 12 cm/j for sand and 2 and 5 cm/j for silt. The purification performances and biofilm development were monitored on 245 for sand filters and 65 days for silt filters. Dissolve oxygen concentration from the treated effluents showed better values for the low loads and for the silt reactors. Also, organic pollutant remove by oxidation (COD and DOC) were better eliminated in the following reactors: Silt (2 cm/j) > Silt (5 cm/j) > Sand (5 cm/j) > Sand (12 cm/j). Adsorption was the mechanism of ammonium removal in silt although nitrification took part in sand. Biofilm development was observed in the first 2.5 cm and 10 cm in the sand reactors loaded at 5 and 12 cm/j respectively.

Pilot plant for wastewater treatment involving septic pit and biological filtration on sand of dunes of the Algerian Sahara

“…Their characterization confirmed their potential to be used as filtration media [11], since the equivalent diameter, the uniformity coefficient, the porosity and the permeability were in the ranges 0.09-0.14 mm, 1.57-2.60, 38-57% and 0.13-0.41 m/h respectively, showing that sand size can be characterized as thin to medium. Physicochemical (Table 1) and chemical (Table 2) characterization of the sand of dunes showed that the characteristics of all the considered quarries were close to those reported in the available literature [8,9,12,13]. It should only be noted high salinity and carbonate values for some quarries: Temacine quarry for salinity, Guemar and El Oued quarries for carbonate values.…”

Evolution of Bacterial Community in Experimental Sand Filters: Physiological and Molecular Fingerprints

“…Wastewater treatment reactors were packed with sand as previously described (Chabaud et al 2006a) and supplied with septic effluent at a nominal load (5 cm/d) and an overload (12 cm/d) corresponding to reactor 1 and 2 respectively (Chabaud et al 2006a). Sand samples (10 cm depth) were removed from the two experimental on-site wastewater treatment reactors and septic effluent, as well as treated effluent were collected.…”

“…In this system, the main removal pollution mechanisms are filtration, adsorption and aerobic degradation by microorganisms arranged in biofilm (Chabaud et al 2006a). The biofilm development in the first centimetres of sand media contributes to the development of clogging zones altering the purification efficiency in soil infiltration treatment system (Stevik et al 2004).…”

Diagnosis of domestic wastewater sand filters

“…The renewed interest in ODWT plants is due to their simplicity of implementation, affordability and efficiency. ODWT plants demonstrate very good performance in treating total organic carbon and ammonia nitrogen (N-NH 4 ) as well as in dealing with suspended solids (SS) (Beal et al, 2005;Chabaud et al, 2006a;Maillard, 1998;Siegrist et al, 2000).…”

“…Numerous studies have been carried out concerning SFVDF systems in the field of ODWT in order to determine their behaviour and the characteristics of the materials to be used in order to obtain good sewage treatment performance (Bruen and Piluk, 1994;Chabaud et al, 2006a;Charles et al, 2005;Jayarathne et al, 2007;Jenssen and Siegrist, 1990;Rolland, 2009;Wanko et al, 2005;Whitehead and Geary, 2000).…”