PRE-TREATMENT OF LANDFILL LEACHATE BY ALKALINIZATION AND CHEMICAL PRECIPITATION

This work had the objective to study the economic and environmental viability of the application of commercial hydrated lime type I (CH-I) and analytical standard sodium hydroxide (NaOH P.A) in alkalization/chemical precipitation processes using landfill leachate. For this, in May/2021, approximately 1 m3 of leachate was collected from the Sanitary Landfill in Campina Grande (ASCG), Paraiba, Brazil, in a tank truck, which was stored in a polyethylene reservoir, in the physical dependencies. from the Federal University of Campina Grande, Headquarters Campus. Subsequently, about 0.001 m3 of leachate were collected, in triplicate, to accomplish the alkalization tests, which aimed to increase the hydrogenic potential (pH) of the referred effluent to 10 ± 1 and 12 ± 1 and to verify the chemical precipitation of copper (Cu), chromium (Cr) and nickel (Ni), as well as the removal of color, turbidity and total ammoniacal nitrogen (NAT), using CH-I and NaOH P.A. The results showed that 28.45 g of CH-I and 5.59 g of NaOH P.A were needed to raise the pH of the leachate to 10 ± 1. Regarding the economic aspect, it is more advantageous to use CH-I in the process of alkalinization/chemical precipitation, since its cost was about 12 (pH = 10 ± 1) and 17 (pH = 12 ± 1) times lower compared to NaOH P.A. It was observed that CH-I presented the best performance in the reduction of apparent color (60 to 90%) and NAT (> 8%), and had similar efficiency to NaOH P.A in the removal of Cr (pH = 12 ± 1), Cu and Ni, reaching values ​​higher than 30, 90 and 40%, respectively. In view of the above results, it was concluded that, both from an economic and environmental point of view, CH-I proved to be the best chemical species to be applied in alkalization/chemical precipitation processes using leachate from a landfill in a semi-arid region.

Bibliographic Details

Main Authors:	Gomes, Naiara Angelo, Calixto, Nayr Thays Henrique, Silva, Elisângela Maria da, Ribeiro, Libânia da Silva, Monteiro, Veruschka Escarião Dessoles, Melo, Márcio Camargo de
Format:	Digital revista
Language:	por
Published:	AIDIS / Instituto de Ingeniería, Universidad Nacional Autónoma de México 2023
Online Access:	https://www.revistas.unam.mx/index.php/aidis/article/view/83582
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