Biodegradabilidade do lodo de água para consumo humano formado durante o processo de coagulação/floculação com os coagulantes policloreto de alumínio e moringa oleifera

Abstract

The treatment process for drinking water production generates a residue (sludge), which according to ABNT NBR 10004 (2004) is classified as solid waste. But usually this sludge is returned to the sources without any treatment, causing considerable environmental impacts. The main objective is to characterize and evaluate the biodegradability of the sludge formed during water treatment with the use of chemical coagulants and natural. For the production of sludge were assayed for coagulation/flocculation in the laboratory with the help of chemical coagulant PAC (Poly Aluminium Chloride) that is widely used in water treatment in the WTP, and Moringa oleifera that is a natural coagulant and is being intensively investigated for that can replace or assist the process of conventional treatment. The results indicate that the studied sludge wastes are classified as Class II A not dangerous - not inert, according to ABNT NBR 10004 (2004). The biodegradability tests showed that the sludge formed by natural coagulants has higher biodegradability compared with the sludge obtained with the use of chemical coagulant. Thus we can conclude that the use of natural coagulants is a viable alternative for the replacement of chemical coagulants, especially regarding the biodegradability of sludge formed and can thus facilitate the disposal of this waste.