Novel, simple, and environmentally safe method for wastewater pollutant removal

In this work, a new methodology has been developed for the elimination of cobalt, nickel and a mixture of both metals from synthetic wastewater in a continuous way. This methodology consists of the electrochemical formation of ferrites of these metals through the oxidation of iron sheets and the reduction of water. Two critical process parameters, current densities and initial pollutant concentration, were analysed. An initial batch prototype resulted in efficiencies on the order of 98% under conditions of applied densities of 50 mA/cm2 and concentrations of both metals of until 100 ppm of the ions. The obtained particles have been characterized by X-ray diffraction to determine the formation of ferrites without the appearance of secondary phases. The formed particle sizes are approximately 30 nm, with hemispherical or flower-like shapes. A flow system prototype was designed for the recirculation of the solution with 100 ppm of both contaminating metals, obtaining approximately 90% recovery with an easy magnetic harvesting. © 2021 The Author

Phosphorous flow analysis and resource circularity at the province level in north Italy

Phosphorus is an essential element for living organisms, but its unequal distribution combined with the current anthropogenic activity make it a critical resource. To decrease the risks of future shortages, new techniques to manage phosphorous are needed to be mainstreamed under a Circular Economy approach to boost a sustainable transition. A full characterization of flows and stocks is necessary to measure the contribution of secondary materials to meet the overall demand in a system and support decision-making process towards potential improvements. This understanding is determinant for a successful implementation of phosphorous recovery at the regional level, where site-specific conditions dictate local constraints. In this study, material flow analysis has been applied to characterize the 2020 phosphorous cycle in the Province of Rimini (Italy) and the State of San Marino, which are served by a wastewater treatment plant with a 560,000 person-equivalent capacity. Our model shows that, about 236 ± 23 t P entered the system, while 155 ± 14 t P left it, resulting in a net accumulation of 81 ± 21 t P, mainly located in soil for crop production, water bodies, and sedimentation due to dissipative flows. The greatest potential for phosphorous recovery is embedded into the digested sludge from the wastewater treatment plant, which would ideally meet 96% of the annual local demand of mineral fertilizers. However, this flow is currently disposed of by landfilling. Further technical, economic, environmental, and regulatory valuations are ultimately needed to build a positive business case to recover phosphorous in the region

Evaluating the most promising sites for wind energy development in Arizona USA: Working paper series--05-09

During the summer of 2003, the state of Arizona took delivery of a set of high-resolution wind energy maps. After applying various exclusions, the developable wind energy potential is 23,290 MW of class 3 or higher, 2,630 MW of class 4 or higher, and 775 MW of class 5 or higher winds. Having determined the potential wind resource, the geographical information system data supplied with the wind maps was used to create a wind resource inventory and to systematically identify the most promising sites for wind energy development. In addition to wind energy potential, proximity to transmission lines and roads, and land ownership were considered in this analysis. Following that, the cost of energy was estimated at a few geographically diverse sites, including class 3, 4, and 5 wind resource areas, at a hub height of 70 m. These estimates revealed that the real levelized cost of energy in 2005 dollars ranged from 4.21 to 5.04 cents per kWh, as the wind class varies from 5 to 3. This paper documents the findings of the wind mapping process, describes the method and results of evaluating the most promising sites for wind development, and presents the cost of energy results