Renewability is not Enough: Recent Advances in the Sustainable Synthesis of Biomass‐Derived Monomers and Polymers

Taking advantage of the structural diversity of different biomass resources, recent efforts were directed towards the synthesis of renewable monomers and polymers, either for the substitution of petroleum‐based resources or for the design of novel polymers. Not only the use of biomass, but also the development of sustainable chemical approaches is a crucial aspect for the production of sustainable materials. This review discusses the recent examples of chemical modifications and polymerizations of abundant biomass resources with a clear focus on the sustainability of the described processes. Topics such as synthetic methodology, catalysis, and development of new solvent systems or greener alternative reagents are addressed. The chemistry of vegetable oil derivatives, terpenes, lignin, carbohydrates, and sugar‐based platform chemicals was selected to highlight the trends in the active field of a sustainable use of renewable resources.     

Mechanistic Insights into a Sustainable Mechanochemical Synthesis of Ettringite

Mechanochemistry offers an environmentally benign and facile synthesis method for a variety of cement paste constituents. In addition, these methods can be used to selectively tune the properties of cement components. The mineral ettringite is an important component of cementitious materials and has additional technological potential due to its ion exchange properties. Synthesis of ettringite via mechanochemistry is an environmentally friendly alternative to conventional wet-chemical synthesis established in industry. This contribution explores the mechanism of a two-step mechanochemical synthesis of ettringite, which was previously found to greatly improve the reaction conversion as compared with one-pot synthesis. The crystallinity of Al(OH)₃ was found to decrease during the first stage of this mechanochemical synthesis. This was correlated to a significant decrease in the particle size of Al(OH)₃ in this stage. No other significant changes were found for the other components, suggesting that mechanochemical activation of Al(OH)₃ is responsible for the enhanced formation of ettringite by the two-step approach. The environmentally friendly approach developed for ettringite synthesis offers a versatile synthetic strategy, which can be applied to synthesise further cementitious materials.     

Conflict minerals (3TG): Mining production,applications and recycling

The growing public awareness of conflict minerals used in consumer electronics and various other devices (e.g. GPS in vehicles, medical equipment, airplane equipment and instruments, etc.) is accompanied by increasing regulatory obligations for companies affected by different laws and certification standards e.g. Dodd Frank Act section 1502, the ICGLR Regional Certification, the OECD Due Diligence Guidance or the planned EU Certification regulation.The so called conflicts minerals are natural mineral resources such as tin, tantalum, tungsten and Gold (3TG) that are critical resources for the electronic and automotive industries but also for other industries (aviation, medical equipment, etc.).Extraction of the 3TGs is widespread and includes primary industrial mining and artisanal mining as well as recycling.     

Laccases: Versatile Biocatalysts for the Synthesis of Heterocyclic Cores

Laccases are multicopper oxidases that have shown a great potential in various biotechnological and green chemistry processes mainly due to their high relative non-specific oxidation of phenols, arylamines and some inorganic metals, and their high redox potentials that can span from 500 to 800 mV vs. SHE. Other advantages of laccases include the use of readily available oxygen as a second substrate, the formation of water as a side-product and no requirement for cofactors. Importantly, addition of low-molecular-weight redox mediators that act as electron shuttles, promoting the oxidation of complex bulky substrates and/or of higher redox potential than the enzymes themselves, can further expand their substrate scope, in the so-called laccase-mediated systems (LMS). Laccase bioprocesses can be designed for efficiency at both acidic and basic conditions since it is known that fungal and bacterial laccases exhibit distinct optimal pH values for the similar phenolic and aromatic amines. This review covers studies on the synthesis of five- and six-membered ring heterocyclic cores, such as benzimidazoles, benzofurans, benzothiazoles, quinazoline and quinazolinone, phenazine, phenoxazine, phenoxazinone and phenothiazine derivatives. The enzymes used and the reaction protocols are briefly outlined, and the mechanistic pathways described.     

DPSIR = A Problem Structuring Method? An exploration from the “Imagine” approach

The Drivers, Pressures, State, Impact and Response or DPSIR framework has been with us for over a decade now and it is widely used as a means to assess and measure and, eventually provide a guide to managing the environment. With its repertoire of diagnostic and analytical components the DPSIR can be argued to be a Problem Structuring Method or PSM. Criticisms of the framework abound but it has a resilience which is noteworthy. Some argue that DPSIR, by its nature, is a narrowly formulated, engineering device, incompatible with the multiple perspectives which human interaction in global ecology requires. Is there a value in DPSIR being more flexible in expression and experience of users? In this article it is shown how the DPSIR framework was applied within a multi-methodology approach called Imagine in a number of coastal management projects around the Mediterranean and in other contexts. The article argues that DPSIR, whilst admittedly limited in its scope and approach can, if applied in a participatory and systemic multi-methodology, combine with other tools and help to create outcomes of value to local populations.     

不同燃料循环方案的可持续性与经济性分析

基于核燃料循环政策技术的成熟度,选取了一次通过循环方案(OTC)、单次复用循环方案(TTC)、快堆闭式循环方案(FRC)及混合堆闭式循环方案(HRC)四种典型的核燃料循环方案进行分析。采用平衡物质流模型对不同燃料循环方案的可持续性进行研究,基于平准化电力成本计算方法对不同方案的燃料成本和乏燃料处置成本进行分析。研究结果表明：闭式燃料循环可极大减少核废料产生; 燃料可自持的FRC方案及HRC方案可使用贫铀做燃料而不消耗天然铀; 仅考虑燃料成本和乏燃料处置成本时,HRC方案的经济性最高而TTC方案的经济性最差。     

可持续发展的环境工程专业应用型人才培养

为了建立可持续发展的环境工程专业应用型人才培养模式,结合欧盟亚洲链项目和德意志学术交流中心（DAAD）项目,建构具有合肥学院特点和可持续发展特性的环境工程专业人才培养模式．具体体现在：加强专业骨干教师培训工作、校际合作,建立国际化教育平台,成立环境技术转化中心和安徽省工程技术研究中心,为专业实践教学和建设服务．     

Chemists around the World,Take Your Part in the Circular Economy!

Based on recent examples and initiatives reported in the literature, this concept article discusses how chemistry can contribute to the circular economy approach in order to improve our current and future economical, societal, and environmental system. Through five proposed levels of contribution, chemists can take a significant part in this global approach via the consideration of green chemistry principles, the simplification of syntheses, the limitation of complex products preparation, the efficient utilization of resources but also the novel ways of waste valorization. A more systematic and generalized environmental and economic assessment from the lab-scale is also recommended. At last, chemists have to work even more collaboratively and in a multidisciplinary way, within chemistry and beyond.     

Recycled high-density polyethylene/gypsum composites: evaluation of the microscopic,thermal, flammability,and mechanical properties

Sustainable composites comprising scraps of high-density polyethylene (HDPE) and gypsum waste in proportions HDPE/gypsum 100/0, 50/50, 40/60, and 30/70 wt% were prepared. The morphology of the injected specimens was core-shell. Thermal, flammability, water absorption, and compression resistance were also evaluated. Progressively, the presence of gypsum increased the HDPE crystallinity and T_onset. Concerning the flammability, the composite 30/70 exhibited the burning rate three times lower than HDPE, indicating that the gypsum played a role as a flame retardant. The HDPE acted as waterproofing for gypsum. The compression resistance of the composites was similar to HDPE.