Terra rossa as the substrate for biological phosphate removal from wastewater

AbstractThree samples of terra rossa were shown to be efficient adsorbents of phosphate [P(V)] from wastewater and removed 29.9–32.6% of P(V). The total iron content in terra rossa was the key factor which determined the P(V) removal from wastewater. The original samples of terra rossa were effective support materials for the immobilization of metabolically active P(V)-accumulating bacteriaAcinetobacter junii(0.56–2.47×1010CFU g–1). The removal of oxalate-extractable iron from original sample of terra rossa increased the number of immobilized bacteria to 1.34×10–11CFU g–1, which is the largest number of immobilized bacteria reported in the literature so far. In reactors containing theA. juniiand terra rossa P(V) was removed from wastewater by simultaneous adsorption onto terra rossa and accumulation inside bacterial cells, resulting in 40.5–62.5% of P(V) removal. Terra rossa is a promising substrate for biological P(V) removal from wastewater, acting both as adsorbent of P(V) and carrier of P(V)-accumulating bacteria.