Alternative treatments for footwear industry liquid effluents. Part 2 Pressure wet oxygen oxidation

• Type: Article in International Scientific Journal
• Date: 2002

Authors

M. J. Ferreira (Author) Other; Manuel Fonseca Almeida (Author) FEUP; Sílvia C. Pinho (Author) FEUP; A. Neves (Author) Other

Journal

Title: Journal of the Society of Leather Technologies and Chemists

Vol. 86

Pages: 101-105

ISSN: 0144-0322

Publisher: Society of Leather Technologists and Chemists

Indexing

ISI Web of Science

Scopus

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

CORDIS: Technological sciences

Other information

Abstract (EN): Small volumes of non-biodegradable liquid effluents are generated in footwear finishing operations. These effluents must be treated to meet regulatory requirements before discharge. Coagulation/flocculation followed by carbon adsorption may allow the discharge of the final effluent to sewage systems but the sludge produced and the adsorbent required makes the process of doubtful feasibility. Even with this treatment, threshold values for discharging the effluent to surface waters are not achieved. Such limitations encountered with these more conventional treatments pushed the research towards other less conventional options. One of them is wet oxidation (WO) here studied with oxygen as the selected oxidant. Thus, experiments were carried out to evaluate the influence of temperature, time, oxygen and pH on the reduction of effluent chemical oxygen demand (COD). In addition, the catalytic effect of copper sulphate on the WO treatment efficiency was evaluated. The WO treatment of these wastewaters using oxygen as oxidant requires at least 200 °C, 30 minutes and non-alkaline pH, preferably pH2. The catalytic effect of copper is only small thus its role is not of interest for this purpose.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5