• Energy Research

Continuous phosphorus discharges in bodies of water, generated by human activities, such as agriculture, domestic effluences or wastewater from industrial processes, produce contaminated water and eutrophication. For this reason, efficient and low-cost systems that can remove phosphorus from contaminated water are necessary. In addition, it is important to generate renewable energy such as the energy produced in biomass power plants, taking advantage of the available biomass waste in each place. When producing this renewable energy, the resulting ash is a residue that can be used for phosphorus removal by adsorption processes. Moreover, according to the concept of the circular economy, the ash waste generated in this bio energy process should be reduced as much as possible. One of the advantages of this research being that surplus phosphorus-laden ash can be reused as fertilizer in agricultural fields. Considering this, the efficiency of reed ash (RA) (Phragmites australis) has been analysed in batch experiments, as well as the effect of several parameters on the removal of phosphate, such as contact time, phosphate-ash ratio, ash dose and temperature. Significant results obtained show that RA can be used to improve water quality.

[EN] The objective of this research is to analyse the feasibility of reusing the fly ash waste, which is produced in biomass plants, during the production of renewable energy, for controlling phosphorus contamination in the wastewater being processed in sewage treatment plants. The research examines the efficiency of using different types of ash, obtained from representative biomass materials after combustion in an energy plant (paulownia wood, wheat straw and barley straw), in removing phosphorus from water. The ashes were respectively mixed with synthetic water, rich in phosphorus; then, using batch experiments, the effects that the pre-treatment of ash, adsorbent dosage, contact time and temperature had on the adsorption process were studied. The main results show that phosphorus adsorption by the tested ashes augments as temperature increases. Similarly, the adsorbed amount of phosphorus increases by increasing the dose of the adsorbent. In addition, the adsorption of phosphorus by these three materials has been described well by the Langmuir isotherm equation. It has been found that the removal process of phosphorus was endothermic. Finally, this study concludes that waste ash from biomass plants can be used to remove phosphorus from wastewater in sewage treatment plants.

Wireless sensor networks are widely used for monitoring different processes, including agriculture, in order to reach sustainability. One of the keys to sustainable crops is water saving. In particular, saving water is extremely important in arid and semiarid regions. In those regions, citrus trees are cultivated, and drip irrigation is used to save water. In this paper, we propose a smart irrigation system for citrus trees using a WSN. We describe the employed sensors and nodes for this proposal. Next, we present the proposed architecture and the operational algorithms for the nodes. Moreover, we designed different algorithms for fault tolerance and energy saving functionalities. The energy saving algorithm is based on the relevance of the gathered data, which is analyzed in order to consider whether the information should be forwarded or not. A TPC-based protocol is proposed to perform the communication among the nodes of our system. In addition, we present different simulations of the proposed system. Particularly, we show the consumed bandwidth and the remaining energy in the different nodes. Finally, we test different energy configurations to evaluate the network lifetime and the remaining energy when the first node depletes its energy.