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Ain Shams University (2016)

BIOTREATMENT OF OLIVE MILL WASTEWATER FOR AGRICULTURAL USES

Ibrahim, Ghada Amin Zaki.

Titre : BIOTREATMENT OF OLIVE MILL WASTEWATER FOR AGRICULTURAL USES

Auteur : Ibrahim, Ghada Amin Zaki.

Etablissement de soutenance : Ain Shams University

Grade : Doctor of Philosophy (PhD) in Environmental Sciences 2016

Résumé partiel
Olive mill waste water (OMWW) is a liquid by-product generated during olive oil production and widely known for its fertilizing value in sustainable agricultural systems. OMWW samples collected from different localities in Egypt were subjected to different chemical, physical and microbiological analysis to determine its quality as fertilizer. The presence of high content of phenolic compounds, COD and BOD were the great challenge to convert this waste rich with nutrients into safe and highly efficient biofertilizer. Aerobic OMWW fermentation processes were conducted to eliminate its phytotoxicity by removal of phenolic compounds present. from twenty nine microbial isolates, the most efficient two bacterial isolates which degraded phenols to a greater extent within a relatively short time were selected for fermentation process and identified by partial 16S rRNA gene sequence analysis as Enterobacter asburiae, and Pseudomonas aeruginosa. Factors affecting the fermentation process and their impact on phenolic compounds degradation were optimized and the results revealed that the optimum pH values were (6 and 7), incubation temperature (250C and 300C), inoculum size (2ml\ 100ml OMWW), nitrogen sources (ammonium sulphate 1gm\L for both microbes), incubation period (27 and 30 days) anaerobic static cultures with 25% OMWW for E. asburiae and Ps. aeruginosa, respectively. Under these conditions of fermentation, phenolic compounds degrading ability was 82.6% for Pseudomonas aeruginosa and 79.9% for Enterobacter asburiae. At the end of fermentation process, high energy components as total phenolic compounds phytohormones, amino acids, and antioxidants were determined using HPLC, amino acid analyzer and spectrophotometer, respectively. HPLC analysis revealed that the degradation rate of phenolic compounds ranged from 75 to 98.5 and 57.5 to 99.16% for Ps. aeruginosa or E. asburiae, respectively. Qurectin, catechol and caffiec acid were subjected to the maximum degradation rate of phenolic compounds while tyrosol, gallic acid and catchin showed less degradation levels by either Ps. aeruginosa or E. asburiae. The phytohormones in the form of gebrillic acid increased in fermented OMWW by Ps. aeruginosa and E. asburiae to 15687.06 ppm and 12915.68 ppm, compared to11815.89 ppm for unfermented control. A remarkable increase in total amino acids in fermented OMWW was detected reaching 459.19 mg\ml and 559.81 mg\ml for OMWW fermented with Ps. aeruginosa and E. asburiae, respectively comparing with unfermented control (1.844 mg\ml). The average concentration of antioxidants (Butylated hydroxyanisole ”BHA” and tertiary butylhydroquinone ”TBHQ”, respectively as standards) using in fermented OMWW by Ps. aeruginosa were (0.869 mol\ l) and (0.831 mol\ l), respectively, while in fermented OMWW by E. asburiae were (0.675 mol\l) and (0.641 mol\l) comparing to unfermented OMWW in which they were (0.862 mol\l) and (0.587 mol\l), respectively. A Pot experiment was conducted at Desert Research Center - Egypt during summer 2012, to evaluate using of raw OMWW and different types of fermented ones as fertilizers using different types of application methods on Sorghum bicolor ( L). The data indicated that application of OMWW fermented with Ps. aeruginosa or E. asburiae applied as soil drench application recorded the maximum positive effects on different traits as height of shoot and length of root, fresh and dry weight of shoot and root and leaf area index while unfermented OMWW recorded the minimum results comparing to control. Also application of fermented OMWW by Ps. aeruginosa and E. asburiae gave the maximum results of NPK, chlorophyll and carbohydrate contents followed by that of unfermented one compared to control (chemically fertilized plants).

Présentation étendue (EULC)

Page publiée le 11 février 2019