| Titre : | Monitoring physicochemical and biological characteristics of date palm waste compost |
| Auteurs : | Abdelouahad Ouali, Auteur ; Fatima Hiouani, Directeur de thèse |
| Type de document : | document multimédia |
| Editeur : | Biskra : Universite Mohamed Khider, 2024-2025 |
| Format : | 126 p. |
| Langues: | Français |
| Mots-clés: | Date palm waste, Composting, Rotary Drum Bioreactor, Initial C/N ratio. |
| Résumé : |
The date palm (Phoenix dactylifera L.) is an important crop in the MENA region, particularly in Algeria, where it is widely cultivated in areas like Biskra. This horticulture produces significant waste that needs to be recycled for sustainable development. Composting is a key method to recycle this agricultural waste, reducing reliance on chemical fertilizers and enhancing soil health. However, composting lignocellulosic wastes, like date palm waste (DPW), presents challenges due to its chemical properties that limit biodegradability. The current research utilized a cost-effective rotary drum bioreactor, which offers various advantages, to establish a decentralized system that enables farmers to manage waste effectively on their farms. Two compost preparation techniques were used. The first employed a ratio of 2:2:6 (DPW : Additives : Water) to achieve a moisture content of 60% , for 60 days composting, with poultry (PM1) and sheep manure (ShP2) as additives. The second approach accelerated decomposition by optimizing the initial moisture content and C:N ratio. A calculation technique was used to formulate a mixture with initial C:N ratios of 25 (CkS25) and 30 (CkS30), regarded as optimal for lignocellulosic composting by numerous studies, and included chicken litter as an additive for a 20-day period. To assist farmers with the mixture proportion calculations, an app was developed, taking into account their limited mathematics knowledge. In all trials, the bio-oxidation periods lasted 18 days, while the thermophilic phases lasted a minimum of 9 days. Throughout the trials, organic matter, moisture content, particle size, and wet bulk density showed a decreasing trend compared to their initial values, whereas other parameters exhibited an increasing trend. By day 20, all trial end products had a dark hue, a soil-like odor, and a low temperature. However, the germination index remained below the acceptable threshold for agricultural application (80%), with only the mixtures CkS25 and CkS30 recording a C:N ratios under 25. After 60 days, mixtures PM1 and ShP2 achieved a germination index around 80. In summary, the bioreactor and the mathematical approach proved effective in improving the initial mix; however, a 20-day period was insufficient for producing a fully mature and stable product. |
| Note de contenu : |
Figures List _______________________________________________________________4 Tables List ________________________________________________________________5 Introduction_______________________________________________________________7 Chapter 01 : Date Palm (Phoenix dactylifera L.)________________________________15 I. Date Palm (Phoenix dactylifera L.) Classification :________________________15 II. Etymologically: ___________________________________________________16 III. History: _________________________________________________________16 IV. Distribution and Production:________________________________________17 V. Botanical Description: _______________________________________________18 V.1. Rhizosphere: ___________________________________________________19 V.2. Trunk: ________________________________________________________20 V.3. Leaves: ________________________________________________________21 V.4. Fruit: _________________________________________________________22 VI. Benefits: _________________________________________________________23 VII. Date Palm Waste: _________________________________________________23 Chapter 02: Composting Process_____________________________________________26 I. History: ___________________________________________________________26 II. Generality:_______________________________________________________26 III. Composting technologies:___________________________________________28 IV. Compostable materials: ____________________________________________30 V. Composting Advantages: _____________________________________________31 VI. Compost benefits: _________________________________________________31 VII. Maturation and Stabilisation: _______________________________________32 VIII. Factors: _______________________________________________________33 VIII.1. Aeration: ____________________________________________________34 VIII.2. Temperature:_________________________________________________36 VIII.3. Moisture Content:_____________________________________________42 VIII.4. potential of Hydrogen (pH):_____________________________________45 Chapter 03: Materials and Methods __________________________________________54 I. Objectives: _________________________________________________________54 II. Study's site: ______________________________________________________54 III. Feedstocks Collection and Recipe preparation Techniques:_______________55 IV. Bioreactor selection and design: _____________________________________59 V. Experimental Setup: _________________________________________________61 VI. Sampling, physicochemical and biological Analysis:_____________________62 VI.1. Temperature:_________________________________________________62 VI.2. Moisture Content:_____________________________________________63 VI.3. Water Holding Capacity: _______________________________________63 VI.4. potential of Hydrogen (pH) and Electrical Conductivity (EC): ________63 VI.5. Total Kjeldahl Nitrogen (TKN): _________________________________63 VI.6. Organic Matter (OM), Total Organic Carbon (TOC) and Biodegradability:______________________________________________________64 VI.7. Nutrient Concentration:________________________________________65 VI.8. Germination Index: ___________________________________________65 VI.9. Bulk density: _________________________________________________65 VI.10. Free Air Space: _______________________________________________66 VI.11. Particle Size: _________________________________________________66 VII. Statistical Analysis: ________________________________________________66 Chapter 04: Results and Discussions__________________________________________68 I. Temperature:_______________________________________________________68 II. Particle Size Distribution (PSD):_____________________________________73 III. Bulk density (BD) and Free Air Space (FAS): __________________________74 IV. Moisture Content:_________________________________________________76 V. potential of Hydrogen (pH):___________________________________________79 VI. Electrical Conductivity (EC): _______________________________________81 VII. Organic Matter (OM) Decomposition: ________________________________83 VIII. C: N progress: __________________________________________________85 IX. Nutrients Content: ________________________________________________88 X. Sensory Analysis (Colour and Odor): ___________________________________90 XI. Germination Index (GI): ___________________________________________93 |
Exemplaires (1)
| Cote | Support | Localisation | Disponibilité |
|---|---|---|---|
| DOC-AGR/110 | These doctorat | bibliotheque departement agronomie | disponible Disponible |
