Fungus-based bioremediation of olive mill wastewater and potential use in horticulture

Proposed treatment processes of OMWW have not been efficient in decreasing its high toxicity or lowering its ecological impact. Bioremediation using microorganisms might be considered an environmentally friendly alternative. In this work, four fungal isolates were tested for their efficacy in lowering the toxicity of OMWW. Results of this work showed that fungal isolates were able to grow on OMWW. However, only one isolate (OMWW2) showed significant lowering in total phenols from 159.27 mg/ml (in controlled untreated water) to 57.75 mg/ml. The treated OMWW was tested on seed gemination of tomato. The results showed 83% germination rates in the presence of treated OMWW compared with 0% rates in nontreated OMWW. The results showed also that OMWW could be used as a supplement fertilizer to the presence of macronutrient and micronutrient. This work provides a promising future treatment OMWW. Further studies are needed to evaluate the possible use of OMWW in horticulture

Nano-ZnO film photocatalysts in bench-scale continuous-flow mineralization of olive mill waste contaminants in water

Olive oil milling, widely practiced in Mediterranean countries, including Palestine, yields the so-called olive mill waste water (OMWW) or Zebar (Zibar). The waste contains minerals and organic materials (including phenols and polyphenols) which undergo continuous oxidation and cause environmental hazards if not well managed. This work basically aims at purifying surface waters, intentionally pre-contaminated with OMWW organic contaminants. Fate of other mineral ions present in the contaminated water is also investigated. ZnO nanoparticles, deposited as films onto glass reactor bottom (165 cm2 area), are described as catalyst for photodegradation of the organic contaminants, in a continuous flow reaction mode (gravity fed, typically at flow rate 3.5 mL/min). Two types of ZnO materials, namely commercial ZnO onto glass (C–ZnO/Glass) and synthetic ZnO supported onto clay and deposited on glass (Syn–ZnO/Clay/Glass), have been examined. The Syn–ZnO/Clay/Glass catalyst is slightly more efficient in removing organic contaminants (~ 43%), compared to the C–ZnO/Glass (41%) in 30 h. Different reaction parameters have been investigated, such as waste dilution factor, exposure duration, pH and catalyst recovery and reuse