Yield, nutrient utilization and soil properties in a melon crop amended with wine-distillery waste

In Spain, large quantities of wine are produced every year (3,339,700 tonnes in 2011) (FAO, 2011) with the consequent waste generation. During the winemaking process, solid residues like grape stalks are generated, as well as grape marc and wine lees as by-products. According to the Council Regulation (EC) 1493/1999 on the common organization of the wine market, by-products coming from the winery industry must be sent to alcohol-distilleries to generate exhausted grape marc and vinasses. With an adequate composting treatment, these wastes can be applied to soils as a source of nutrients and organic matter. A three-year field experiment (2011, 2012 and 2013) was carried out in Ciudad Real (central Spain) to study the effects of wine-distillery waste compost application in a melon crop (Cucumis melo L.). Melon crop has been traditionally cultivated in this area with high inputs of water and fertilizers, but no antecedents of application of winery wastes are known. In a randomized complete block design, four treatments were compared: three compost doses consisted of 6.7 (D1), 13.3 (D2) and 20 t compost ha-1 (D3), and a control treatment without compost addition (D0). The soil was a shallow sandy-loam (Petrocalcic Palexeralfs) with a depth of 0.60 m and a discontinuous petrocalcic horizon between 0.60 and 0.70 m, slightly basic (pH 8.4), poor in organic matter (0.24%), rich in potassium (410 ppm) and with a medium level of phosphorus (22.1 ppm). During each growing period four harvests were carried out and total and marketable yield (fruits weighting <1 kg or visually rotten were not considered), fruit average weight and fruit number per plant were determined. At the end of the crop cycle, four plants per treatment were sampled and the nutrient content (N, P and K) was determined. Soil samplings (0-30 cm depth) were carried before the application of compost and at the end of each growing season and available N and P, as well as exchangeable K content were analyzed. With this information, an integrated analysis was carried out with the aim to evaluate the suitability of this compost as organic amendment.

Desulfurization of pyrolysis fuel produced from waste lube oils, tyres and plastics

Sulphur compounds remaining in petroleum fractions from topping, hydroskimming or deep conversion processes are a growing concern for oil refiners since in the lapse of a few years the sulphur specification for motor fuels has dropped from 500 mg/kg to 10 mg/kg in most European countries. This increasingly stringent regulation has forced refineries to greatly improve their hydrodesulfurization units, increasing the desulfurization rates and thus consuming huge amounts of hydrogen.

Impact of a value chain approach on the sustainability of solid waste management in Mukuru Kwa njenga informal settlements Nairobi, Kenya

En un mundo altamente urbanizado, la gestión de residuos sólidos es un problema primordial en toda ciudad. Las ciudades de paises en desarrollo deben además afrontar retos que no afectan a las ciudades de paises desarrollados. En los paises en desarrollo muchas municipalidades sufren un crecimiento descontrolado de los asentamientos informales sin planificación urbana que hace muy complicada una adecuada gestión de los residuos sólidos urbanos, situación que se agrava al no contar estas con suficientes recursos económicos para llevar a cabo su responsabilidad en cuanto a provisión del sevicio básico de recogida de residuos. La provisión de servicio de recogida de residuos por parte de SHGs (grupos de ayuda comunitarios) en estos asentamientos informales puede ayudar a resolver algunos de estos problemas. Para que esta oportunidad sea completamente explotada, los ingresos de estos grupos deben ser garantizados, teniendo en cuenta que la sostenibilidad de estos grupos depende enteramente de ello. Este estudio pretende averiguar cómo un enfoque de cadena de valor puede mejorar la sostenibilidad de la gestión de residuos sólidos, permitiendo asegurar los ingresos de los recolectores informales de residuos. El estudio propondrá después de analizado el actual sistema, mejoras que permitan desarrollar un medio ambiente saludable en los asentamientos informales donde se desarrolla el estudio. Para alcanzar este objetivo, se ha desarrollado una investigación específica en Nairobi (Kenia) en el asentamiento precario de Mukuru Kwa Njenga, analizando los distintos aspectos relevantes que tienen influencia en una gestión integrada de residuos sólidos y las relaciones entre los distintos actores que tienen influencia en la misma.

Effects of biochar prepared from organic waste on soil properties

Biochar is a carbon-rich solid obtained by the thermal decomposition of organic matter under a limited supply of oxygen and at relatively low temperatures. Biochar can be prepared from the pyrolysis of different organic feed- stocks, such as wood and biomass crops, agricultural by-products, different types of waste or paper industry waste materials . The pyrolysis procedure of waste, i.e. sewage sludge, has mainly two advantages, firstly, it removes pathogens from waste and, secondly, biochar can reduce the leaching of heavy metals present in raw sewage sludge. This trend of the use of waste material as feedstocks to the preparation of biochar is increasing in the last years due to industrial development and economic growth imply an increase in waste generation. The application of biochar may have positive effects on soil physical properties as water holding capacity and structure or on soil biological activity and soil quality. Also, biochar can be used to remove water pollutants and can be used in multiple ways in soil remediation due to its adsorption of pesticides or metals. Also, biochar contribute to carbon sequestration due to carbon stability of biochar materials. The objective of this presentation is to review the positive effects of the biochar prepared from organic waste on soil properties.

Factors impacting the market share of Construction and Demolition (C&D) Waste recycling solutions

Current EU Directives force the Member States to assure by 2020 that 70% of the Construction and Demolition (C&D) waste is recovered instead of landfilled. While some countries have largely achieved this target, others still have a long way to go. For better understanding the differences arising from local disparities, six factors related to technical, economic, legislative and environmental aspects have been identified as crucial influences in the market share of C&D waste recycling solutions. These factors are able to identify the causes that limit the recycling rate of a certain region. Moreover, progress towards an efficient waste management can vary through the improvement of a single factor. This study provides the background for further fine-tuning the factors and their combination into a mathematical model for assessing the market share of C&D recycling solutions.

Approach to the potential production of giant reed in surplus saline lands of Spain

Growing energy crops on marginal land has been promoted as a way of ensuring that biomass production involves an acceptable and sustainable use of land. Saline and saline-prone agricultural lands represent an opportunity for growing energy crops avoiding the displacement of food production and contributing to restoration of degraded land. Giant reed (Arundo donax L.) is a perennial grass that has been proposed as a promising energy crop for lignocellulosic biomass production while its tolerance to salinity has been proved. In this work, the identification of surplus saline lands that could be irrigated with saline waters for growing tolerant-energy crops (giant reed) in the mainland of Spain and the assessment of the agronomically attainable yield in these limiting growing conditions were undertaken. To this purpose, a GIS analysis was conducted using geodatabases related to saline areas, agro-climatic conditions, irrigation water requirements, agricultural land availability, restrictions regarding the range of electrical conductivity tolerated by the crop, competition with agro-food crops and irrigation water provisions. According to the approach developed, the irrigated and saline agricultural area available and suitable for biomass production from giant reed amounted up to 34 412 ha. The agronomically attainable yield in these limiting conditions was estimated at 12.7 – 22.2 t dm ha−1 yr−1 and the potential production of lignocellulosic biomass, 597 338 t dm yr−1. The methodology followed in this study can be applied to other target regions; it allows the identification of this type of marginal lands, where salinity-tolerant plant species could be grown for bioenergy purposes, avoiding competition with agro-food crops, and where soil restoration measurements should be undertaken.

Determinación del riesgo de incendio en una instalación de secado de alperujo = Determination of the risk of fire in an olive-oil mill waste dryer

For the energy valorization of alperujo, residue of the olive oil two phases extraction process, it is necessary to perform a drying process to reduce moisture content from over 60% to less than 10%. In order to reduce primary energy consumption and get an economic return, usually in this kind of drying facilities Gas Turbine CHP is used as a heat source. There have been recently in Spain some fires in this kind of GT-CHP facilities, which have caused high material losses. In some of these fires it has been suggested that the fire was caused by the output of incandescent alperujo in the flue gasesof the drying system. Therefore, the aim of this study is to determine experimentally and analytically under which operational conditions a process of alperujo self-ignition in the drying process can begin, and determine the actual fire hazard in this type of TG-CHP system. For analytical study, the temperature and initial composition of the combustion gases of the Gas Turbine at the entrance of the drying process was calculated and the gas equilibrium conditions reached in contact with the biomass were calculated and, therefore, the temperature of the biomass during the drying process. Moreover, the layer and dust ignition temperature of alperujo has been experimentally determined, according to EN 50281-2-1: 2000. With these results, the operating conditions of the drying process, in which there are real risk of auto-ignition of alperujo have been established.Para la valorización energética del alperujo, residuo del proceso de extracción en dos fases del aceite de oliva, es necesario realizar un proceso de secado para reducir su contenido de humedad de más del 60% al 10% m/m en b.h. Con el fin de reducir el consumo de energía primaria y obtener una rentabilidad económica, normalmente en este tipo de instalaciones de secado se usa la cogeneración con turbina de gas (TG) como fuente de calor. En España en los últimos años han ocurrido algunos casos de incendio en este tipo de instalaciones de cogeneración, que han supuesto pérdidas materiales muy elevadas. Por esta razón, el objetivo de este trabajo es determinar analítica y experimentalmente las condiciones operativas del secadero bajo las cuales podría comenzar un proceso de autoinflamación del alperujo y determinar el riesgo real de incendio en este tipo de instalaciones. Para el estudio analítico, se ha planteado y validado el modelo matemático que permite calcular la temperatura y la composición de los gases de combustión a la entrada y a la salida del secadero, en función de las curvas características de la TG, de las condiciones atmosféricas, del caudal y del grado de humedad de la biomasa tratada. El modelo permite además calcular la temperatura de bulbo húmedo, que es la máxima temperatura que podría alcanzar la biomasa durante el proceso de secado y determinar la cantidad de biomasa que se puede secar completamente en función del caudal y de las condiciones de entrada de los gases de combustión. Con estos resultados y la temperatura mínima de autoinflamación del alperujo determinada experimentalmente siguiendo la norma EN 50281- 2-1:2000, se demuestra que en un proceso de secado de alperujo en condiciones normales de operación no existe riesgo de autoencendido que pueda dar origen a un incendio.