Photodegradation of olive mill wastewater with sunlight using nano-ZnO-SiO2 composite, its reusability and the quality of treated water

Ulusoy C., SPONZA D. T.

INTERNATIONAL JOURNAL OF GLOBAL WARMING, vol.19, pp.106-126, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 19
  • Publication Date: 2019
  • Doi Number: 10.1504/ijgw.2019.101775
  • Journal Name: INTERNATIONAL JOURNAL OF GLOBAL WARMING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.106-126
  • Keywords: ZnO-SiO2, photocatalytic degradation, olive mill wastewater, OMW, sunlight irradiation, reuse, recovery, PHOTOCATALYTIC DEGRADATION, ADVANCED OXIDATION, ZNO NANOPARTICLES, TIO2, ADSORPTION, PHENOL, ACID, DYES
  • Dokuz Eylül University Affiliated: Yes

Abstract

In this study, nano-ZnO-SiO2 was used to treat pollutants from olive mill industry wastewaters (OMW) by photo-degradation. The effects of increasing nano-ZnO-SiO2 concentrations (0.5 g/L, 1 g/L 3 g/L, 5 g/L and 10 g/L), photooxidation times in sunlight (8, 16, 24 and 36 hours) and different pHs (4, 7 and 10) were evaluated in the treatment of OMW pollutants. The maximum pollutant yields for chemical oxygen demand (COD), total phenol and total solids (TS) were 77%, 73% and 64% with a nano-ZnO-SiO2 concentration of 3 g/L after 24 hours of sunlight irradiation at pH 4. It was found that the treated olive mill wastewater (OMW) can be used again after eight sequential treatments with total COD and total phenol yields as high as 99%. The treated water was evaluated based on irrigation purposes. The total cost to treat 1L of OMW containing the seven nano composite expenses is 1.95 euro.