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Structure and Classification of 2D Monoelemental Materials (Xenes)
Published in Zongyu Huang, Xiang Qi, Jianxin Zhong, 2D Monoelemental Materials (Xenes) and Related Technologies, 2022
The group ⅤA Xenes are phosphorene (P), arsenene (As), antimonene (Sb), and bismuthene (Bi).1 There are a variety of allotropes in group ⅤA elements. In nature, phosphorus has white, red, black phosphorus and other several amorphous forms.40,41 Arsenic has three common allotropes, which are metallic gray, yellow, and black arsenic.42 Antimony has three allotropes, which are gray antimony, black antimony, and explosive antimony.1 And bismuth has one stable structure, which is gray arsenic. Among them, the most stable structures are black phosphorus, gray arsenic, gray antimony, and gray arsenic. There are two phases that have been isolated in natural layered crystals, α phase and β phase, as shown in Figure 1.2. With the exploration of the five groups of phosphorene allotropes by theoretical calculation, more phase structures have been found. Zhang et al. systematically proposed nine-phase structures, including five typical honeycomb (α, β, γ, δ, ε) and four non-honeycomb (ζ, η, θ, ι) structures as shown in Figure 1.4.4, 3There are five typical honeycomb (α, β, γ, δ, ε) and four non-honeycomb (ζ, η, θ, ι) structures of the group ⅤA allotropes. Reproduced from Ref. 43 with permission. Copyright 2016, Wiley.
31P
Published in Guillaume Madelin, X-Nuclei Magnetic Resonance Imaging, 2022
Owing to its high reactivity, white phosphorus must be stored under water and is usually used to produce phosphorus compounds, which are mainly used in fertilizers. Phosphorus is essential to life, but the natural cycling of phosphorus through the biosphere is slow. Therefore, phosphorus-based fertilizers are critical to supply many essential plant nutrients in crop production. Red phosphorus is formed by heating white phosphorus to 250°C and is used in safety matches, fireworks, smoke bombs and pesticides. Black phosphorus is also formed by heating white phosphorus using mercury as a catalyst, but has no significant commercial uses. Other applications based on phosphorus compounds are detergents, baking powder, glass, water softeners, soft drinks, pharmaceuticals, met al treatments, fluorescent light bulbs, and television sets.
Challenges, Innovations, and Future Prospects in Transforming Future Wastewater Treatment Plants into Resource Recovery Facilities
Published in Sreedevi Upadhyayula, Amita Chaudhary, Advanced Materials and Technologies for Wastewater Treatment, 2021
Biofuels from municipal wastewater treatment plants will become economical only if governments can provide subsidies to compete with commercial supplies and those that produce and distribute traditional coal, natural gas, and petroleum. The effluent from the wastewater treatment has a high heat content and is currently being dissipated into the environment. Wastewater treatment plants should focus on the recovery of this waste heat in addition to the traditional capture of the heat from the co-generation using anaerobic sludge digestion. As nations plan on seriously cutting greenhouse gas emissions and limiting global temperature rise this century to well below 2°C above pre-industrial levels, a serious commitment to the reduction in the fresh consumption of fossil fuels is being sought. The recovery of energy from wastewater is more important now than ever before. Energy companies can work with wastewater treatment plants to achieve carbon neutrality as part of the economic and market-based approach of carbon trading. The same philosophy may be applied to fertilizer production facilities to consider wastewater resource recovery units as their partners in the conservation of nutrients and thus lower some of their own environmental footprints. Phosphorus removal technologies have been very expensive, and hence future efforts should focus more on technologies that recover phosphorus than its removal from wastewaters. Technologies must be further improved with a goal to reduce energy consumption in nitrogen recovery.
Process variables that defined the phytofiltration efficiency of invasive macrophytes in aquatic system
Published in International Journal of Phytoremediation, 2023
Yetunde Irinyemi Bulu, Nurudeen Abiola Oladoja
Phosphorus (P) is a key plant nutrient in fertilizer production, and a salient precursor in the production of varieties of industrial products (e.g., detergents, animal feed, and beverages). In an aqueous system, P exists as dissolved and particulate inorganic P, and dissolved and particulate organic P, but the dissolved inorganic P is the most readily bioabsorbable form (Figure 2) (Yoshimura et al.2007; Yu et al.2019). Anthropogenic activities, that produce excessive P in water leads to the unabated proliferation of aquatic flora (i.e., eutrophication). The bloom of the aquatic flora cause reduction in sunlight penetration, and the dissolved oxygen concentration, which affects aquatic lives, and in severe cases, lead to their death. The dead aquatic lives enhance microbial activities and further reduced the dissolve oxygen concentration of the water (Bulu and Saliu 2021).
Preparation of Fe-filled MOF-Al-based hydrogel for efficient reclaim of phosphate from wastewater and reusing as a slow-release fertilizer
Published in Environmental Technology, 2022
Zhengxian Wang, Jiankang Lu, Chengyi Wu
Phosphorus (P), as a vital nutrient element for nature, was widely distributed in water, soil, sediment and organisms [1,2]. With the rapid development of economy and population, a large amount of P-rich sewage and industrial wastewater were discharged into the environment. In addition, the overuse of P-containing pesticides and fertilizers in agriculture was a major factor in phosphorus pollution. Excess levels of phosphorus in the water led to eutrophication and promote the growth of harmful substances, which will pose a potential threat to drinking water safety and aquatic ecosystems [3–5]. According to the report of the 2017 Ecological Environment Bulletin of China, 30.28% of the 109 monitored lakes were eutrophicated and 61.47% are in the process of eutrophication [6]. Phosphate in water is the direct P-source of eutrophication. Many government agencies have published various strict laws to restrict the discharge of phosphate wastewater. For instance, in EU, the concentration of phosphate in wastewater should not exceed 0.1 mg P/L [7]. The US Environmental Protection Agency claimed that the total phosphate concentration did not exceed 0.05 mg P/L [8]. Therefore, how to reduce the content of phosphate in water is the main issue to control eutrophication.
Zebra mussel shells as an alternative mineral resource for lime production as a phosphorus precipitant
Published in Environmental Technology, 2022
Kenton McCorquodale-Bauer, Nazim Cicek
Eutrophication is caused by an overabundance of nutrients, primarily phosphorus, in a body of water [6]. Phosphorus enters rivers, and subsequently lakes, through runoff of agricultural fertilizers and animal waste, commercial and residential lawn fertilizer, and sewage release. Excess phosphorus allows blue green algae, also known as cyanobacteria, to grow in large blooms [6]. When these blooms die and decompose, dissolved oxygen is consumed which can result in anoxic conditions in waterbodies [6], which in turn leaves respiring macrophyte organisms in distress. One means of reducing phosphorus loading is to remove phosphorus in wastewater effluents using chemical treatment, such as the use of lime, which is currently used as a chemical precipitant in wastewater treatment and removes phosphorus through the formation of calcium phosphates. In regions where lakes and rivers are negatively affected by both phosphorus overloading and invasive zebra mussels, using the overabundance of zebra mussel shells for an alternative source of lime for phosphorus removal in local sewage lagoons could serve as a sustainable way to reduce two ecological-social problems. One such area is Lake Winnipeg, located in the province of Manitoba, Canada, where eutrophication and invasive zebra mussels present significant ecological, economical, and societal issues.