Quantificação da areia retida no pré-tratamento de esgoto de uma cidade com solo arenoso

Abstract

Environmental sanitation is an issue of utmost relevance for modern society, playing a crucial role in preserving public health and the environment. One of its essential stages involves wastewater treatment, which includes preliminary processes such as the removal of solids, including sand. This stage is particularly important in coastal regions, where environmental characteristics directly influence waste composition, requiring efficient systems to ensure treatment quality and minimize environmental impacts. The Baldo Wastewater Treatment Plant (WWTP), inaugurated in 2011 in the city of Natal, plays a vital role in waste management and wastewater treatment in the region. The plant handles considerable volumes of wastewater in an area characterized by sandy soil, which has specific properties. In this context, the primary objective of this research was to investigate the interference of sand in the wastewater retention process at the Baldo WWTP, aiming to understand the effectiveness of the treatment procedures adopted in sandy soils. The methodology included a literature review to identify the problems caused by the presence of sand in wastewater treatment, combined with a case study that provided relevant information about the influence of local geology on treatment efficiency. The results showed that the average sand retention aligns with the values reported in the literature. According to the Brazilian standard NB-570, the amount of sand removed per 1,000 cubic meters of wastewater should range from 30 to 40 liters, demonstrating the efficiency of the pre-treatment system for sand removal used at the Baldo WWTP.