Absorption of phosphorus from wastewater by aged refuse excavated from municipal solid waste landfill

Municipal solid waste(refuse) landfill stabilizes as the refuse degrades. After years of biodegradation, the refuse in the landfill becomes stabilized and aged, which may vary with the local climate, humidity, and composition of refuse placed. In this work, it is found that the refuse with an age of over 8 years at Shanghai Refuse Landfill has been significantly stabilized and sufficiently aged and is thus suitable for excavation. The 8-year old aged refuse is mechanically screened, and the fine fractions of refuse(aged refuse) with a diameter less than 2 cm are then used as a biological absorbent for removal of both inorganic and organic phosphorus in livestock wastewater and prepared aqueous solution. It is proved that the aged refuse is very effective for the quantitative removal of both types of phosphorus. The absorption mechanism is proposed. It is considered that phosphorus is firstly absorbed onto the surface of the aged refuse and then used as a substrate for the growth of microorganisms which ultimately leave the aged refuse as sludge.