RESUMO
Development of electrode materials exhibiting exceptional phosphate removal performance represents a promising strategy to mitigate eutrophication and meet ever-stricter stringent emission standards. Herein, we precisely designed a novel LaCeOx heterostructure-decorated hierarchical carbon composite (L8C2PC) for high-efficiency phosphate electrosorption. This approach establishes an internal electric field within the LaCeOx heterostructure, where the electrons transfer from Ce atoms to neighboring La atoms through superexchange interactions in La-O-Ce coordination units. The modulatory heterostructure endows a positive shift of the d band of La sites and the increase of electron density at Fermi level, promoting stronger orbital overlap and binding interactions. The introduction of oxygen vacancies during the in situ nucleation process reduces the kinetic barrier for phosphate-ion migration and supplies additional active centers. Moreover, the hierarchical carbon framework ensures electrical double-layer capacitance for phosphate storage and interconnected ion migration channels. Such synergistically multiple active centers grant the L8C2PC electrode with high-efficiency record in phosphate electrosorption. As expected, the L8C2PC electrode demonstrates the highest removal capability among the reported electrode materials with a saturation capacity of 401.31 mg P g-1 and a dynamic capacity of 91.83 mg P g-1 at 1.2 V. This electrochemical system also performs well in the dephosphorization in natural water samples with low concentration that enable effluent concentration to meet the first-class discharge standard for China (0.5 mg P L-1). This study advances efficient dephosphorization techniques to a new level and offers a deep understanding of the internal electric field that regulates metal orbitals and electron densities in heterostructure engineering.
Assuntos
Eletricidade , Fosfatos , Capacitância Elétrica , Carbono , EletrônicaRESUMO
The carbon peaking and carbon neutrality targets proposed by the Chinese government have initiated a green transformation that is full of challenges and opportunities and endowed sustainable development strategy for combating global warming issue. It is essential to execute comprehensive identification and carbon reduction measures across all industries that produce greenhouse gas (GHG) emissions. Water supply system, as an energy-intensive sector, plays a crucial role in GHG reduction. This work conducted a life cycle assessment (LCA) to account the GHG emissions associated with the construction and operation phases of the drinking water treatment plant (DWTP). During the construction phase, the total GHG emissions were 19,525.762 t CO2-eq, with concrete work and rebar project being the dominant contributors (87.712%). The promotion of renewable or recyclable green building materials and low-carbon construction methods, such as the utilization of prefabricated components and on-site assembly, holds significant importance in reducing GHG emissions during the construction phase of DWTP. Regarding the operation stage, the DWTP possessed an average annual GHG emission of 37,660.160 t CO2-eq and an average GHG intensity of 0.202 kg CO2-eq/m3. Most emissions were attributed to electricity consumption (67.388%), chemicals utilization (12.893%), and heat consumption (10.414%). By increasing the use of clean energy and implementing strict control measures in the water supply pumps, energy consumption and GHG emissions can be effectively reduced. This study offers valuable insights into the mapping of GHG emissions in the DWTP, facilitating the identification of key areas for targeted implementation of energy-saving and carbon-reducing measures.
Assuntos
Água Potável , Gases de Efeito Estufa , Animais , Dióxido de Carbono/análise , Efeito Estufa , Carbono , Estágios do Ciclo de VidaRESUMO
Under the current meat sheep breeding system, newborn lambs usually live with their mothers until weaning, and in daily management, they often need to be separated from their ewes for a short period due to dehorning, disease treatment, etc. Such short-term separation was considered to be a high-intensity stress for the lambs. This study aimed to explore the effects of 1 h sensory separations on behaviors and the concentration of stress-related indicators of small-tailed Han lambs. Lambs were assigned to four groups: auditory, visual, and tactile separation (AVT) group; visual and tactile separation (VT) group; tactile separation (T) group; and control (C) group. Then they were separated from their mothers for one hour on postnatal days 14, 21, 28, 35 and 42. Results showed the separated lambs (AVT, VT, and T groups) spent less time lying down relaxing and more time looking around, exploring, vocalizing, and attempting to escape (P < 0.05). Lambs separated by lack of tactile contact only exhibited the most escaping and moving behavior. Twin-born lambs showed less moving, escaping, and vocalizing than single-born lambs (P < 0.05). The separation also led to a rise in serum globulin levels and a decrease in tetraiodothyronine. In conclusion, this study showed that temporary 1 h ewe-lamb separations could affect behaviors and the serum levels of stress indicators of lambs. The behavioral responses were more obvious when lambs were separated by lack of tactile contact only, and in single-born lambs. It can conclude that indicated that when lambs need to be temporarily separated from ewes in daily management production, it would be better to let them stay together with their littermates, and make them avoid hearing or seeing the ewes, such management may partially reduce the separation stress, thereby improving the welfare and breeding efficiency of sheep.