Evaluation of potentially toxic elements in the sanitary sewer system arising from informal and home productive arrangement in the jewelry and fashion jewelry chain from Limeira, SP, Brazil

Author(s)

Fernanda Junqueira Salles

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Saúde Pública (FSP/CIR)
• Defense date: 2017-08-08

Examining board members

Kelly Polido Kaneshiro Olympio; Renato Sanches Freire; Rubia Kuno; Adelaide Cassia Nardocci

• Advisor: Kelly Polido Kaneshiro Olympio; Wanderley da Silva Paganini

Abstract

Introduction: Electroplating is part of the jewelry and fashion jewelry manufacturing process and causes toxic substances elimination in the sludge and liquid effluents. The outsourcing informal home practices adopted in some regions of Limeira-SP, Brazil in the productive arrangement of jewelry and fashion jewelry raises a concern for its environmental impact. Objectives: This study assessed the presence/concentration of potentially toxic elements (PTEs: As, Cd, Cr and Cr-VI, Cu, Hg, Ni, Pb, Sn and Zn) in Limeira sewage system and compare the PTEs concentration to the Brazilian and other countries legislation limits. Methods: The sanitary sewage samples (n=540) were collected in 15 manholes of different areas during two campaigns in the year 2016. The three collection areas are: industrial area, area with a concentration of families inserted in the informal productive arrangement of jewelry and fashion jewelry and area without known industrial or informal activities. During each month, 3 weekly collections were made, during three weeks, in two periods for day (morning and afternoon). The sewage sludge (n=12), raw sewage (n=12) and treated sewage (n=12) were collected in two Limeiras WWT (AS and TATU), which operates with different treatment process. Most of PTEs determination was performed by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP OES), Hg concentration was determined by Direct Mercury Analyzer (DMA) and Cr-VI by UV-Vis. Total Organic Carbon (TOC) concentration was determined to estimate de sewage dilution by the High-Temperature Combustion Method and Wet-Oxidation. Results: Most PTEs results were found be lower than the detection limit of the instrumental techniques. Cr-VI, Cu, Ni and Zn were quantified in concentrations within the State of São Paulo decree N.8.468. Cr-VI concentrations in sanitary sewage ranged from 0.0093 to 0.61 mg L-1, Cu ranged from <0.02 to 4.24 mg L-1, Ni ranged from <0.02 to 6.16 mg L-1 and Zn ranged from <0.02 to 1.34 mg L-1. Four sanitary samples exceeded Cu or Zn values permitted by decree to be discharged into sewage treatment networks. A significant difference was found between values above and below the 75th percentile for campaign and TOC values (p<0.015). The treated sewage from AS WWT presented low concentrations of Cu (p<0.05), Zn (p=0.02) and Ni (p=0.01) compared to treated sewage from TATU WWT. In the sludge samples, the Cu means exceeded the values of the CONAMA 375/2006 resolution (1,500 mg kg-1) and the Zn results were very close to the legislation (2,800 mg kg-1). Conclusions: The heterogeneity of the results, observed on random days, can indicate the sporadic nature of the sanitary disposal of PTEs. Our study found PTEs in the sanitary sewage, which are used in the production of jewelry and fashion jewelry and may precipitate and concentrate on the sludge. The high concentrations of Zn and Cu in the sludge require its controlled destination (AU)

• FAPESP's process: 15/21253-0 - Evaluation of the presence of potentially toxic elements arising from jewelry industries in the sanitary waste waters collection system in Limeira - SP
• Grantee: Fernanda Junqueira Salles
• Support Opportunities: Scholarships in Brazil - Master