Olive Solid Waste Research Articles

Composites based on (ethylene–propylene) copolymer and olive solid waste: Rheological, thermal, mechanical, and morphological behaviors

In the olive oil‐producing countries, large quantities of olive solid waste are dumped in nature causing several environmental problems. Therefore, the use of this by‐product as filler in (ethylene–propylene) matrix could be an effective way to reduce significantly the quantities of the disposed biomass and elaborate a cost‐effective material. However, the hydrophilic nature of this natural filler decreases the compatibility with the hydrophobic matrix. To improve the interfacial adhesion, maleated polypropylene was added as a compatibilizing agent. In a first step, the influence of the filler loading on the rheological, thermal, and mechanical properties was investigated. Composites with various filler contents were prepared by melt blending using a twin‐screw extruder and injection molding. The filler addition led to an increase of the viscoelastic properties and the crystallinity degree. Then, the coupling agent (MAPP) was reported to enhance the rheological, thermal, and mechanical properties of the composites up to a critical amount beyond which the plasticizing effect becomes more predominant than the reinforcing effect, a fact that could be responsible for the decrease of viscoelastic properties, crystallinity, and mechanical properties. POLYM. ENG. SCI., 56:27–35, 2016. © 2015 Society of Plastics Engineers

Management of Olive Grove Pruning and Solid Waste from Olive Oil Extraction Via Thermochemical Processes

Olive oil production is a significant economic activity in the Mediterranean basin and a considerable employment source, while the environmental pressures associated with the olive tree farming and olive oil extraction are remarkable and increasingly important. Olive farming and olive oil processing are generating large quantities of solid and liquid wastes, the disposal of which are still considered as a major problem for the farmers and the mill operators. The commonly applied management practice of combustion is not fully in line with sustainability criteria. Taking into consideration that the average size of olive groves and olive mills in the Mediterranean countries is relatively small, the management of olive farming wastes via thermochemical routes could develop an energy self-maintained decentralized system that contributes to the conservation of natural resources and is in line with the principles of ecology and sustainable agriculture. In this context, this work investigates pyrolysis and gasification as potential scenarios for waste management in the case of an olive grove of 10 hectares. The results have shown that the produced electricity, in both cases, is not only enough to cover the energy required for milling operations but is also producing a surplus that can be supplied to the grid and sold, thus providing an extra income to the farmer, boosting the economic viability of all the process. Pyrolysis, in addition, has the advantage of providing a soil amendment (bio-char), thus enhancing soil quality and carbon sequestration into the soil.

Solid olive waste in environmental cleanup: Enhanced nitrite ion removal by ZnCl2-activated carbon

This communication describes how olive solid wastes can be used to prepare activated carbon (AC), with soundly high surface areas, suitable to remove nitrite ions from water. Solid olive wastes, so called Jeft, separated as unwanted bi-products from olive oil mills, have been converted into charcoal. The charcoal was then physically and/or chemically activated using different compounds namely conc. H3PO4 or ZnCl2. Charcoal carbonization was performed under inert atmosphere to avoid loss of heated carbon by oxidation with air. Surface area measurements and SEM micrographs showed that activation using ZnCl2 yields AC with highest surface area and more porous surfaces. The ZnCl2-activated carbon was then used to remove nitrite ions from water by adsorption. Effects of different parameters on value of surface area and adsorption capacity of the AC were investigated. Commercial AC materials were used as reference for comparison. The AC showed higher adsorption capacity toward nitrite than other reported adsorbents. The results suggest that using 5g of the ZnCl2-activated carbon per liter of heavily nitrite-contaminated water (50ppm) may bring the contaminant concentration down to the WHO accepted concentration limits within 60min. This work highlights the future feasibility of using olive waste as feed stocks to produce useful renewable materials while keeping in mind the wisdom “make wastes work in environmental protection”.

Energy recovery alternatives for the sustainable management of olive oil industry waste in Australia: life cycle assessment

Over the last two decades, the olive oil industry in Australia has been growing at an annual rate of 9%. Nevertheless, the highly polluting solid waste and wastewater generated by the industry poses significant challenges for the environmental sustainability of the industry. This paper analysed five alternatives for managing this waste stream using life cycle assessment methodology. The options included manufacturing briquettes as solid fuel for home heating; pellets for domestic or industrial water heating; pyrolysis and composting. The functional unit used in this study is the processing of 1 Mg of olive solid waste at the mill. Emissions were categorised into eight impact categories: ozone layer depletion potential (ODP), global warming potential (GWP100), eutrophication potential (EP), acidification potential (AP), human toxicity (HTP), fossil fuel depletion potential (FDP), ionising radiation potential (IRP), and photochemical oxidant formation potential (POFP). The study showed that although composting (current best practices – CBP) can achieve significant environmental benefits, using the olive waste to produce energy products may achieve better results, especially when displacing electricity from the main grid. The production of pellets for use in domestic hot water boilers (PHWH) is the option that is likely to deliver the highest environmental benefits. For example, GWP100 and ODP of the PHWH were estimated to be −1057 kg CO2-Eq, −1.5 × 10−5 kg CFC-11-Eq compared to −12.4 kg-CO2-Eq and 5.3 × 10−8 kg CFC-11-Eq achieved by the CBP, respectively. Future energy scenario and transportation distances were identified as significant parameters affecting the performance of the options. Sensitivity analysis showed that the expected change in the future Australian energy mix to cleaner energy sources is unlikely to have a significant effect on the performance of the alternatives. The results also showed little sensitivity to transportation distances of the energy product to the end user. This paper is the first to evaluate options for energy utilisation of olive solid waste using life cycle assessment and compare it to industry current best practices (composting). Although the paper focuses on the Australian olive oil industry, the results are also relevant to other countries and regions were olive solid waste is generated in relatively moderate quantities but distributed over large geographic area.

Cellulose acetate from biomass waste of olive industry

In the present work cellulose powder was extracted from olive industry solid waste and then converted into cellulose acetate. The cellulose powder was extracted from olive industry solid waste by kraft pulping process and multistep bleaching p sequences. An elemental chlorine-free chemical bleaching sequence chlorine dioxide (D)-cold caustic extraction (E)-hypochlorite (H)-hydrogen peroxide (P) was used. Cellulose powder was obtained in about 35 % yield. The extracted cellulose and cellulose acetate made from thereof were extensively characterized using Fourier transform infrared spectroscopy, electron microscopy sciences, gel-permeation chromatography/high-performance liquid chromatography, and viscometry. Our key finding in this study was that olive industry solid waste is a valuable source of cellulose powder and its derivatives. This is important, since our results show how lignocellulosic agricultural wastes could be utilized and converted into cellulose products with high value.

Impregnation of olive mill wastewater on dry biomasses: Impact on chemical properties and combustion performances

Mediterranean countries generate large amounts of olive oil byproducts mainly OMWW (olive mill wastewater) and EOSW (exhausted olive solid waste). Although solid residues have various valorization strategies, there is no economically viable solution for the OMWW disposal. This study aims to recover the OMWW organic contents through solid biofuels production. Hence sawdust and EOSW were used for the OMWW impregnation. The potential of the obtained samples, namely: IS (impregnated sawdust) and IEOSW (impregnated exhausted olive solid waste) were evaluated. Therefore, the physicochemical characterizations and thermogravimetric analyses of the samples were first performed. Secondly, the samples densification into pellets and their combustion in a domestic combustor were carried out. Combustion efficiencies, gaseous and PM (particulate matter) emissions as well as ash contents were evaluated.The analysis finding shows that addition of OMWW leads to an increase of energy content through the heating values increase. An increase of the impregnated samples reactivity was observed and assigned to the potassium catalytic effect. Combustion performances show that the OMWW addition has not a negative effect on their firing quality. Moreover, a beneficial effect on the pollutant emissions is observed with IEOSW pellets. The developed strategy constitutes a promising issue for the OMWW disposal and recovery.

Biodegradation of olive mills wastewater using thermophilic bacteria

Biodegradation of olive mill wastewater (OMW) toxic constituents was investigated using thermophilic bacteria. Three types of thermophilic bacteria were isolated from olive mills solid waste (Jift) and tested their ability to detoxify OMW. These thermophiles, namely Bacillus polymaxa JT6, Bacillus Maceramns JT7 and Bacillus popilliae JT8, can grow on Zebar as a main carbon source. The optimal growths of thermophiles were obtained at temperature of 65°C and pH of 6.4. The growth of the three thermophiles on Zebar was descending with increasing Zebar concentration. Complete inhibition of thermophiles was observed when the total solid concentration of Zebar was above 20 g/L. This suggests the need for a pretreatment process for Zebar prior to the biological treatment or the use of diluted Zebar solution. Moreover, the growth rate of the thermophiles on Zebar solution of 8 mass% was described by Monod growth model.

Assessing the impact of agro-industrial olive wastes in soil water retention: Implications for remediation of degraded soils and water availability for plant growth

Olive solid waste (OSW) is a toxic by-product of olive oil production. Disposal of OSW is a major problem in many Mediterranean countries leading to increased interest in its potential as an organic fertiliser. Relatively little is known regarding the impact of augmentation with OSW and olive solid waste compost (OSWC) on soil hydraulic properties. The effect of OSW and OSWC on the hydraulic characteristics of common agricultural soils with high sand but very different silt and clay contents was analysed. Increased organic inputs induced reductions in soil bulk density and increases in air capacity, hydraulic conductivity and the water content available for plant growth (AWC) in the Sandy Clay Loam (SCL) soil. Similar patterns were observed in Loamy Sand (LS) soil augmented with OSW, but OSWC caused reductions in hydraulic conductivity, air capacity and AWC. Nonetheless, over longer timescales OSWC may benefit the hydraulic properties of loamy sand soils as the compost becomes fully incorporated within the soil structure. Augmentation with organic olive waste induced the hydraulic parameters of the sandy clay loam soil to become identical to those loamy sand (LS) with a higher available water capacity; suggesting that soil augmentation with OSW and OSWC may be an effective tool in remediating and improving degraded or organic poor soils. In terms of the improvement of hydraulic parameters, application rates of 6–8% OSW/OSWC were most beneficial for both soil types.

Development and optimisation of a non conventional extraction process of natural dye from olive solid waste using response surface methodology (RSM)

Dyes obtained from different natural sources have emerged as an important alternative to synthetic dyes.In this study, optimisation of natural colorant non-conventional extraction technique from olive waste was investigated using response surface methodology. The combined effects of extraction conditions on total phenolic content (TPC) and relative color strength (K/S) were studied using a three-level three-factor Box–Behnken design. The optimum conditions for dye extraction were found to be 0.14mol/L, 62.11min, 71.23°C and 4.5g for sodium hydroxide concentration, extraction time, temperature, and mass of the waste, respectively.The efficiency of extraction under these optimum conditions was found to be 1133.86mg/L of phenolics and relative colour strength (K/S) equal to 23.22. Further, Fourier Transform Infrared Spectroscopy was used to identify the major chemical groups in the extracted dye.

Devolatilization behavior and pyrolysis kinetics of potential Tunisian biomass fuels

Biomass thermochemical conversion is complex and requires a good understanding of the thermal decomposition process. This process may be identified using mass loss kinetics which are useful for the design of proper equipment used for biomass conversion.This work aims to determine devolatilization kinetic parameters characterizing four Tunisian biomass species: industrial by product (Pine Sawdust), agro‐industrial by product (Olive Solid Waste), agricultural residue (Date Palm Trunk) and seaweed (Posidonia Oceanica) using data from non‐isothermal thermogravimetry and the Coats and Redfern calculation method.Decomposition TG and DTG data were analyzed by applying 10 kinetic models including processes governed by nuclei growth, surface nucleation followed by geometric, diffusion and chemical reaction models. Obtained results show that biomass pyrolysis is represented by two successive steps: (i) devolatilization stage characterized by high weight loss rate, which is well described by diffusional, surface nucleation followed by geometric and first order chemical reaction models. (ii) char formation stage characterized by low weight loss rate, which is well described by second order and third order chemical reaction models. © 2014 American Institute of Chemical Engineers Environ Prog, 33: 1452–1458, 2014

Effect of multi-ingredient of Bokashi on productivity of mandarin trees and soil properties under saline water irrigation

This study was carried out during 2012 and 2013 seasons at El-Sheikh Zuwayid ,North Sinai Governorate, Egypt, to study the effect of mult-ingredient of bokashi on N, P, K, Fe, Zn, Cu, Ca, Mn and Mg in the leaves, yield as well as some physical and chemical characteristics of Clementine mandarin fruits and soil properties under saline water irrigation. Seven treatments were done as follows: T1: control treatment (normal sandy soil), T2: poultry manure 10 kg/ tree, T3: bokashi1 (poultry manure + solid olive waste +EM+ molasses) 10 kg/ tree, and T4: bokashi 2 (poultry manure + rice straw +EM+ molasses) 10 kg/ tree. T5: bokashi 3 (poultry manure + rice husks +EM+ molasses) 10 kg/ tree, T6: bokashi 4 (poultry manure + solid olive waste + rice straw +EM+ molasses) 10 kg/ tree and T7: bokashi 5 (poultry manure + solid olive waste + rice husks+ EM+ molasses) 10 kg/ tree. The obtained results showed that all treatments were very effective on leaves mineral content, yield, physical and chemical characteristics of the fruits and chemical characteristics and micro flora soil. Generally, the best treatment was T6 which improved the mineral content (N, K, Fe, Zn, Cu, Ca and Mn) in the leaves, yield, fruit length, fruit diameter, fruit weight, fruit volume, juice percentage, T.S.S, total sugar, and vitamin C. In addition , T6 treatment increased the number of the soil micro flora, (total fungi (TF), total bacteria (TB) and total actinomycetes (TA) and some macro and micro elements (N, P, K, Fe, Zn, and Mn) while decreased the total acidity, peel thicknesses in fruits, ECe, pH and Na in soil as compared to the control.

Effect of ultrasonic pretreatment on biomethane potential of two-phase olive mill solid waste: kinetic approach and process performance.

The effect of ultrasound (US) pretreatment on two-phase olive mil solid waste (OMSW) composition and subsequent anaerobic biodegradation was evaluated by chemical oxygen demand solubilization and biochemical methane potential (BMP) tests. OMSW was ultrasonically pretreated at a power of 200 W and frequency of 24 kHz for time periods of 20, 40, 60, 90, 120, and 180 minutes, corresponding to specific energies of 11367, 21121, 34072, 51284, 68557, and 106003 kJ/kg total solids, respectively. In order to evaluate the US pretreatment, a low, medium, and high exposure time, that is, 20, 90, and 180 min, were selected for BMP tests. Methane yields of 311 ± 15, 393 ± 14, and 370 ± 20 mL CH4/g VSadded (VS: volatile solids) were obtained for 20, 90, and 180 minutes, respectively, while the untreated OMSW gave 373 ± 4 mL CH4/g VSadded. From a kinetic point of view, the BMP tests showed a first exponential stage and a second sigmoidal stage. In the first stage, the kinetic constant obtained for US pretreated OMSW at 20 minutes was 46% higher than those achieved for the pretreated OMSW at 90 and 180 minutes and 48% higher than that for untreated OMSW. The maximum methane production rate achieved was 12% higher than that obtained for untreated OMSW.

Biosorption performance, combustion behavior, and leaching characteristics of olive solid waste during the removal of copper and nickel from aqueous solutions

Several researchers have proved that agricultural by-products constitute good adsorbents for removing heavy metals from aqueous solution. However, few investigations have identified efficient strategies for the adsorbent′s regeneration. Hence, a global methodology for the removal of copper and nickel metals from wastewater including metal biosorption, thermal treatment and residual ash landfill is proposed. In order to validate this strategy, olive solid waste (OSW), provided by an olive oil mill from Tunisia, were used to remove copper and nickel on batch experiments. Copper and nickel were adsorbed on a monolayer of OSW surface with maximal adsorption capacity (q max) of 3.6 and 1.7 mg g−1, respectively. Contaminated OSW with copper and nickel were combusted at 850 °C in an electrical furnace. About 96 % of each metal was recovered in residual ashes that present a good secondary raw material for copper and nickel production. Low leaching transfers (≤4 %) were observed for copper and nickel from residual ashes leading to the possibility to be landfilled. Therefore, the suggested process can be used as an alternative to the classical technologies for effluent decontamination.

The Application of Solid Olive Waste as Reinforcement in Carboxylated Nitrile Butadiene Rubber/Organo Nano Layered Silicates Composites

The Application of Solid Olive Waste as Reinforcement in Carboxylated Nitrile Butadiene Rubber/Organo Nano Layered Silicates Composites

Effects of olive solid waste and olive solid waste compost application on soil properties and growth of Solanum lycopersicum

Mediterranean countries are the largest global producers of olive oil. One by-product of this industry, and a major environmental problem, is olive solid waste (OSW). This study aims to explore the potential of OSW and olive solid waste compost (OSWC) for reuse and recycling as an agricultural fertiliser. Typical Sandy and Loamy agricultural soils were augmented with increasing amounts of OSW and OSWC (0, 4, 8 and 10%) in order to investigate the effect on soil characteristics and growth of tomato (Solanum lycopersicum). Plant growth was dramatically reduced by the application of OSW Composting of OSW results in a break-down of toxic compounds. Consequently, augmentation of soils with OSWC enhanced seed-germination, plant and root biomass and total nitrogen content. Application of 4–8% OSWC produced the optimal effect on soil parameters across all treatments, while plant growth subsequently decreased when OSWC application was increased to 10%. These results suggest that composting of OSW has the greatest potential beneficial impacts for the use of this agri-industrial waste as an agricultural fertiliser. To ensure optimal impact on crop production application of OSWC should be within 100–210 tonnes per hectare, and not exceed 260 tonnes, significantly greater than current standard compost application rates.

Impact of solid and liquid olive oil waste applications on important soil properties

Some of the agricultural waste has important economic potentials to be used as a source of plant nutrients and as soil conditioner. Olive oil solid and liquid waste (OSLW) is one of them. Some of the characteristics of this material are favorable for agriculture, such as low pH and high content of organic matter, N, P, K, and Mg. This study was carried out at the Research Farm of Faculty of Agriculture, Adnan Menderes University Aydin for two years. Olive oil solid and liquid waste was applied as liquid and solid forms with three doses (liquid OSLW 0–2.5–5.0–7.5 l m−2, solid OSLW 0–1.5–3.0–4.5 kg m−2). Results indicate that organic matter contents were slightly risen up with the applications of olive oil waste while soil pH decreased with both liquid and solid forms of waste applications. There were also increases in organic matter, N, P, K, and Mg contents with rise of application doses. It was also determined that the undesired effects of Na and EC in soils, important for environmental pollution, disappeared through the experimental period.

Cellulose powder from olive industry solid waste

In the present work, a method for extracting cellulose from olive industry solid waste has been developed. The method involves subjecting solid olive waste to kraft pulping, followed by multistep bleaching processes. The totally free chlorine chemical bleaching sequence APEP was the most effective and gave an average cellulose yield of about 35%. The extracted cellulose was extensively characterized using FTIR, EMS, HPLC, and viscometry. Our key finding in this study is that the extracted cellulose was found to have physio-chemical properties that are similar to those of conventional microcrystalline cellulose (MCC). This is important, as our results show how lignocellulosic agricultural wastes can be utilized to produce high value cellulose powder.

Effects of olive oil solid waste on growth and nutrient uptake of faba bean, onion, and radish plants

Although, olive oil industry is crucial for Turkey, olive oil solid waste or olive vegetation water, a by-product of the industry, leads to environmental pollution during olive oil production. This study investigated the fields where olive oil solid waste was used as an organic substance. Olive oil solid waste in different concentrations (0, 10, 20, 30 and 40 t ha-1) were applied to faba bean, onion and radish plants grown (in 1 m2 plots) in the field conditions. Germination rates and growth of the plants were monitored. The application at the rates of 10 to 30 t ha-1were determined as the most appropriate rates for both faba bean and onion. The higher rates of application negatively affected germination and growth of plants. The application at 20 t ha-1 concentration of olive oil solid waste provided the best results for faba bean and onion plants. However, none of the application rates were found suitable for radish. Keywords: Olive oil solid waste; germination; plant growth; plant analysis

Energetic valorisation of olive mill wastewater impregnated on low cost absorbent: Sawdust versus olive solid waste

The oil extraction industry generates two by-products, an aqueous effluent, olive mill wastewater (OMWW) and a solid residue, olive mill solid waste (OMSW). OMWW is considered as the major pollutant in the Mediterranean area causing severe environmental threats. The main problem regarding the disposal of OMWW is to find an environmental and economical viable solution. A new valorisation strategy has been carried out which includes the following steps: (a) absorption of OMWW on low-cost renewable absorbents, (b) natural evaporation of the water and (c) energy recovery by combustion of the impregnated absorbents. Sawdust and OMSW were selected as low-cost renewable absorbents. Thermal behaviour of the impregnated samples was studied under inert and oxidative atmosphere from 20 °C to 900 °C using thermogravimetric analysis (TGA). Kinetic parameters were obtained and compared for the different samples. Gaseous emissions such as CO2, CO and volatile organic compounds (VOC) were measured under oxidative conditions at 500 °C, 600 °C and at 700 °C in a fixed bed reactor. The results indicate that for samples containing the same amount of OMWW, the reaction time of impregnated sawdust is lower compared to impregnated OMSW. Combined treatment of OMMW proposed in this study may be a promising method for the reduction of their environmental impact and for the energetic valorisation of the organic content of OMWW.

Valorisation of Olive Oil Solid Wastes: Valuable Compounds Recovery Using High Pressure- High Temperature

Valorisation of Olive Oil Solid Wastes: Valuable Compounds Recovery Using High Pressure- High Temperature