

@article {2229,
	title = {{Treatment of domestic sewage at low temperature in a two-anaerobic step system followed by a trickling filter.}},
	journal = {Water science and technology : a journal of the International Association on Water Pollution Research},
	volume = {48},
	number = {11-12},
	year = {2003},
	month = {jan},
	pages = {199{\textendash}206},
	abstract = {The treatment of domestic sewage at low temperature was studied in a two-anaerobic-step system followed by an aerobic step, consisting of an anaerobic filter (AF) + an anaerobic hybrid (AH) + polyurethane-foam trickling filter (PTF). The AF+AH system was operated at a hydraulic retention time (HRT) of 3+6 h at a controlled temperature of 13 degrees C, while the PTF was operated without wastewater recirculation at different hydraulic loading rates (HLR) of 41, 15.4 and 2.6 m3/m2/d at ambient temperature (ca. 15-18 degrees C). The AF reactor removed the major part of the total and suspended COD, viz. 46 and 58\% respectively. The AH reactor with granular sludge was efficient in the removal and conversion of the anaerobically biodegradable COD. The AF+AH system removed 63\% of total COD and converted 46\% of the influent total COD to methane. At a HLR of 41 m3/m2/d, the COD removal was limited in the PTF, while at HLR of 15.4 and 2.6 m3/m2/d, a high total COD removal of 54-57\% was achieved without a significant difference between the two HLRs. The PTF was mainly efficient in the removal of particles (suspended and colloidal COD removal were 75-90\% and 75-83\% respectively), which were not removed in the anaerobic two-step. The overall total COD removal in the AF+AH+PTF system was 85\%. Decreasing the HLR from 15.4 to 2.6 m3/m2/d, only increased the nitrification rate efficiency in the PTF from 22\% to 60\%. Also, at HLR of 15.4 and 2.6 m3/m2/d, PTF showed a similar removal for E. coli by about 2 log. Therefore, the effluent of AF+AH+PTF system can be utilised for restricted irrigation in order to close water and nutrients cycles. Moreover, such a system represents a high-load and a low-cost technology, which is a suitable solution for developing countries.},
	issn = {0273-1223},
	author = {Elmitwalli, T A and van Lier, J and Zeeman, G and Lettinga, G}
}
