Anaerobic reactor/high rate pond combined technology for sewage treatment in the Mediterranean area.
Two high-rate, anaerobic/aerobic units were used to treat the sewage of the Institut Agronomique st Vétérinaire Hassan II (Morocco) campus in a 1,100 m2-plant designed for 1,500 e.p. and receiving 63 m3 per day. The anaerobic pre-treatment consisted of a two-step up-flow anaerobic reactor (TSUAR) comprising two reactors and one external settler all in series. The aerobic line, or post-treatment, consisted of a high-rate algal pond (HRAP) and one maturation pond in series. The system totalized a hydraulic retention time (HRT) of 9 days. A gravel filter (GF) was constructed behind the TSUAR to trap low-density particles. The TSUAR removed 80% of COD and 90% of SS within 48 h. Solids retention time in the reactors averaged 32 d with a specific sludge production of 0.28 g SS g(-1) COD removed. Almost 93% of the sludge evacuated from the settler was stabilized. Specific biogas production from both reactors was 0.25m3 kg(-1) COD removed. Used in this configuration, the HRAP lost its BOD removal activity and increased its nutrients and pathogens removal capabilities (tertiary treatment). Results showed that 85% of total nitrogen and 48% of total phosphorus were removed by the HRAP. Land area requirement of this combination was less than 1 m2 per capita and filtered final effluent was of excellent quality (COD, 82 mg/l; TKN, 8.3 mg/l; total P, 2.7 mg/l, faecal coliforms, 2.4 10(3)/100 ml and zero helminths eggs).
El Hafiane
F
F
Wastewater Treatment and Reuse Unit, Department of Rural Engineering, Institut Agronomique et Veterinaire Hassan II (IAV), BP 6202, Rabat-lnstituts, Morocco.
El Hamouri
B
B
D000641:Ammonia / Q000302:isolation & purification; D000693:Anaerobiosis; D000818:Animals; D001673:Biodegradation, Environmental; D019149:Bioreactors; D004531:Eggs; D004755:Enterobacteriaceae / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D006376:Helminths / Q000302:isolation & purification; D008522:Mediterranean Sea; D009018:Morocco; D009584:Nitrogen / Q000302:isolation & purification; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D010758:Phosphorus / Q000302:isolation & purification; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*
D012722:Sewage; D010758:Phosphorus; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen