Biowaste and vegetable waste compost application to agriculture

The landfilling of biodegradable waste is proven to contribute to environmental degradation. Compost use in agriculture is increasing as both an alternative to landfilling for the management of biodegradable waste, as well as means of increasing or preserving soil organic matter. This research aimed to contribute to the identification of a system for managing the utilization of vegetable waste (agricultural plant-tissue waste) and biowaste (source-separated biodegradable municipal solid waste) composts for sustainable agriculture, with particular regards to nitrogen availability and leaching.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Biowaste and vegetable waste compost application to agriculture

The landfilling of biodegradable waste is proven to contribute to environmental degradation. Compost use in agriculture is increasing as both an alternative to landfilling for the management of biodegradable waste, as well as means of increasing or preserving soil organic matter. This research aimed to contribute to the identification of a system for managing the utilization of vegetable waste (agricultural plant-tissue waste) and biowaste (source-separated biodegradable municipal solid waste) composts for sustainable agriculture, with particular regards to nitrogen availability and leaching

Considerations for recycling of compost and biosolids in agricultural soil

Regulatory pressures, economic factors and the increasing production of organic waste promote the recycling of compost and biosolids to agricultural land. Sustainable recycling requires an in-depth understanding of the various processes involved when dealing with organic materials. These include interactions in the soil–crop system and the wider environment. The fertiliser value of compost and biosolids depends on the nutrient content of the materials, notably nitrogen, phosphorus and potassium, and their availability to plants. Compost and biosolids constitute slow release fertilisers since most of the nitrogen and phosphorus is not readily available for plant uptake. Furthermore, imbalances in their nutrient composition can negatively affect their agronomic performance. The development of nutrient-enriched biosolids (organomineral fertilisers) appears to be a sustainable alternative for recycling to agricultural land as it deals with the problems associated with nutrient imbalances and release. Further research is necessary to develop suitable techniques for compost nitrogen enrichment in order to improve its nitrogen fertiliser value

Purification of Olive Mill Wastewater Using Microfiltration Membrane Technology

Olive mill wastewater (OMWW), a by-product of the olive oil extraction process, is a severe polluting waste, but also a source of antioxidants; polyphenols, especially hydroxytyrosol. This study aimed at investigating the potential of microfiltration (MF) for separating the polyphenols from OMWW. OMWW treatment consisted of a preliminary centrifugation step, followed by MF for the separation of fats and polyphenols. Two types of ceramic MF membranes were used. MF flux ranged between 78 and 95 kg m-2 h-1, indicating the applicability of the described process on commercial scale. Better results were obtained with MF membrane of 50 nm pore size, due to its higher porosity compared to the membrane of 200 nm pore size. The optimum operative conditions were transmembrane pressure of 3.5 bar, flow rate of 10 m s-1, and temperature of approximately 55 °C. A 3-month storage of OMWW prior to treatment resulted in a 20% decrease in permeate flux, indicating that direct processing of the OMWW is necessary. Membrane pollution was not a problem for MF operation and did not affect membrane permeability significantly. Restoring the permeability of water to baseline levels after each use, confirmed the successful cleaning regime applied. The microfiltrate was an excellent antioxidant, which contained useful polyphenols, including hydroxytyrosol, tyrosol, p-coumaric acid, caffeic acid and catechin

Physical and Aerodynamic Properties of Lavender in relation to Harvest Mechanisation

A laboratory study evaluated the physical and aerodynamic properties of lavender cultivars in relation to the design of an improved lavender harvester that allows removal of flowers from the stem using the stripping method. The identification of the flower head adhesion, stem breakage, and aerodynamic drag forces were conducted using an Instron 1122 instrument. Measurements on five lavender cultivars at harvest moisture content showed that the overall mean flower detachment force from the stem was 11.2 N, the mean stem tensile strength was 36.7 N, and the calculated mean ultimate tensile stress of the stem was 17.3 MPa. The aerodynamic measurements showed that the drag force is related with the flower surface area. Increasing the surface area of the flower head by 93% of the "Hidcote" cultivar produced an increase in drag force of between 24.8% and 50.6% for airflow rates of 24 and 65 m s −1 , respectively. The terminal velocities of the flower heads of the cultivar ranged between 4.5 and 5.9 m s −1 , which results in a mean drag coefficient of 0.44. The values of drag coefficients were compatible with well-established values for the appropriate Reynolds numbers

Maize Fertigation with Treated Olive Mill Wastewater: Effects on Crop Production and Soil Properties

The present study investigates the potential of olive mill wastewater, treated by microfiltration and XAD4 macroporous resin, to be used as liquid fertilizer in maize production through a 2-year field experiment. The treated olive mill wastewater (T-OMWW) was applied at two rates of 25 t and 50 t per ha per year, supplemented with mineral fertilization. There was also a treatment involving the application of only T-OMWW at the rate of 50 t per ha per year, and an only mineral fertilizer treatment. Mineral fertilizers and T-OMWW were applied progressively through a drip irrigation system. Maize grain and soil analysis showed that T-OMWW was capable to meet crop requirements in N, P and K, and increase soil N, P and K availability. There was a tendency for increasing soil Na and electrical conductivity (EC) using the higher rate of T-OMWW. Therefore, for sustainable agriculture, it may be safer to apply the T-OMWW at the lower rate of 25 t per haper year, or use the higher rate of 50 t per haevery other year