SEWAGE TREATMENT IN DOMESTIC REACTOR ANAEROBIC REACTOR OF HYBRID FOLLOWED WITH ALGAE IMMOBILISED

Abstract

This study was performed aiming to evaluate the fecal contamination indicator and nutrient removals in immobilized algae reactor in post-treatment of anaerobic effluent. An Hybrid Anaerobic Reactor (HAR) fed with sewage was installed and its effluent post treated with Immobilized Algae Reactor (IAR). The RAI operated with moving-bed biofilm characteristics, and the support medium was polyurethane foam cut in cubes. The experiments were operated in three distinct phases at a greenhouse. The first one was characterized by a low insolation and temperature at a range from 22.4 to 30.2 ºC. At second phase ammonium sulfate was added to stimulate the nitrification. At the third phase the reactor was exposed to a greater insolation with temperature between 23.4 and 33.3ºC. The HAR provided an expressive organic matter and suspended solids removals, with 77 and 88% efficiency respectively. The IAR the N-NTK removal efficiency were respectively 96, 79 and 62% for the three phases. Nitrification occurred at first and second phases, at these phases the phosphorus removal was not efficient. On the other hand the third phase obtained a removal efficiency of 87% for orthophosphate and 99.98% for E. coli. The polyurethane was revealed as a good support medium for algae immobilization, being possible to efficiently remove the nutrients and the fecal contamination indicator organisms.

Key Words: indicares faecal contamination, nutrients, reactor immobilized algae.