Phthalocyanines Synthesis: A State-of-The-Art Review of Sustainable Approaches Through Green Chemistry Metrics.

Driven by escalating environmental concerns, synthetic chemistry faces an urgent need for a green revolution. Green chemistry, with its focus on low environmental impacting chemicals and minimized waste production, emerges as a powerful tool in addressing this challenge. Metrics such as the E-factor guide the design of environmentally friendly strategies for chemical processes by quantifying the waste generated in obtaining target products, thus enabling interventions to minimize it. Phthalocyanines (Pcs), versatile molecules with exceptional physical and chemical properties, hold immense potential for technological applications. This review aims to bridge the gap between green chemistry and phthalocyanine synthesis by collecting the main examples of environmentally sustainable syntheses documented in the literature. The calculation of the E-factor of a selection of them provides insights on how crucial it is to evaluate a synthetic process in its entirety. This approach allows for a better evaluation of the actual sustainability of the phthalocyanine synthetic process and indicates possible strategies to improve it.

The management and prevention of food losses and waste in low- and middle-income countries: A mini-review in the Africa region.

This mini-review analyses food losses and waste (FLW) management in low- and middle-income countries (LMICs) and identifies potential strategies to improve FLW management efficiency on the African continent. To achieve this aim, a search of grey and published scientific literature-case studies, feasibility studies, theses, peer-reviewed journals, governments and technical reports was performed. Food waste (FW) per capita in sub-Saharan Africa (SSA) was determined to be between 6 and 11 kg capita-1 year-1. Factors militating against FLW management include a lack of infrastructure, waste reduction and mandatory waste management plans, financial support for food redistribution programmes, awareness and a lack of knowledge of FW management and effective approaches. Poor recovery systems, a lack of incentives in FW recycling programmes, a lack of a regulatory and policy framework and institutional weaknesses as well as a lack of sufficient and appropriate education programmes to improve FW source separation and collection rates are all significant challenges in the African region, with negative consequences for the environment and public health. Except for fuel conversion and food scraps for digestion to recover energy, there is a huge potential for composting and using FW as a digestate, which could eventually lead to a reduction in the amount of FW being landfilled or incinerated. The study explores potential interventions to reduce amount of FLW and form a basis for future research in this field and improving FW management efficiency in LMCs, especially on the continent of Africa. It also provides information that could assist researchers, policymakers and decision-makers reduce amount of FLW, aid in the utilization of FW for energy production, and reduce greenhouse gas emissions in the continent, as well as support the achievement of other sustainable development goals, such as 12.3, which is particularly important in the context of the African continent, which is dependent on food imports.

Value-Added Upcycling of PET to 1,4-Cyclohexanedimethanol by a Hydrogenation/Hydrogenolysis Relay Catalysis.

We present an innovative process for directly transforming poly(ethylene terephthalate) (PET), a polymer extensively used in food and beverage packaging, into trans-isomer-enriched 1,4-cyclohexanedimethanol (CHDM), a key ingredient in advanced specialty polymers. Our approach leverages a dual-catalyst system featuring palladium on reduced graphene oxide (Pd/r-GO) and oxalate-gel-derived copper-zinc oxide (og-CuZn), utilizing hydrogenation/hydrogenolysis relay catalysis. This method efficiently transforms PET into polyethylene-1,4-cyclohexanedicarboxylate (PECHD), which is then converted into CHDM with an impressive overall yield of 95 % in a two-stage process. Our process effectively handles various post-consumer PET plastics, converting them into CHDM with yields between 78 % and 89 % across different substrates. Additionally, we demonstrate the applicability and scalability of this approach through a temperature-programmed three-stage relay process on a 10-gram scale, which results in purified CHDM with an isolated yield of 87 % and a notably higher trans/cis ratio of up to 4.09/1, far exceeding that of commercially available CHDM. This research not only provides a viable route for repurposing PET waste but also enhances the control of selectivity patterns in multistage relay catalysis.

Separation of Tellurium from Metal Chalcogenides through Mild Anhydrous Chlorination.

The separation of tellurium from cadmium telluride is examined using a unique combination of mild, anhydrous chlorination and complexation of the subsequent tellurium tetrachloride with 3,5-di-tert-butylcatecholate ligands (dtbc). The resulting tellurium complex, Te(dtbc)2 , is isolated in moderate yield and features a 103 to 104 reduction in cadmium content, as provided by XRF and ICP-MS analysis. Similar results were obtained from zinc telluride. A significant separation between Te, Se, and S was observed after treating a complex mixture of metal chalcogenides with this protocol. These three tunable steps can be applied for future applications of CdTe photovoltaic waste.

Waste of electrical and electronic equipment management from the perspective of a circular economy: A Review.

In addition to the difficulties involved in the management of conventional solid waste, the management of waste of electrical and electronic equipment (WEEE) is significantly more complex due to its unusual chemical composition and fast generation. Both developed and developing countries have been looking for solutions to deal with the problems caused by the growing flow of WEEE, especially regarding sustainable solutions based on reducing resource exploitation by the recovery of materials from this type of waste. In this context, this work presents a quali-quantitative and comprehensive literature review of the publications on the management of WEEE, from the perspective of a circular economy. The results showed that the first publications on the topic appear in 2006, with a significant increase from 2015, the year when the Circular Economy Action Plan was instituted in the European Community. The most prominent authors have been giving emphasis to researches on recycling, reuse and technologies for the recovery of materials/energy from WEEE. Nevertheless, few studies have been found focusing on the prevention/reduction in WEEE generation, priority actions of the WEEE management hierarchy. The works analysed show that the current management of WEEE, despite considering the circularity of materials, prioritizes the development of technological solutions of the end-of-pipe type, greatly represented by the recovery of materials, instead of preventing the generation, which may be detrimental to long-term sustainability. The work ends with the presentation of a SWOT-TOWS (strengths, weaknesses, opportunities and threats) analysis conducted to define the main strategies for the improvement of WEEE management from a circular economy perspective.

Modular Functionalization of Metal-Organic Frameworks for Nitrogen Recovery from Fresh Urine.

Nitrogen recovery from wastewater represents a sustainable route to recycle reactive nitrogen (Nr). It can reduce the demand of producing Nr from the energy-extensive Haber-Bosch process and lower the risk of causing eutrophication simultaneously. In this aspect, source-separated fresh urine is an ideal source for nitrogen recovery given its ubiquity and high nitrogen contents. However, current techniques for nitrogen recovery from fresh urine require high energy input and are of low efficiencies because the recovery target, urea, is a challenge to separate. In this work, we developed a novel fresh urine nitrogen recovery treatment process based on modular functionalized metal-organic frameworks (MOFs). Specifically, we employed three distinct modification methods to MOF-808 and developed robust functional materials for urea hydrolysis, ammonium adsorption, and ammonia monitoring. By integrating these functional materials into our newly developed nitrogen recovery treatment process, we achieved an average of 75 % total nitrogen reduction and 45 % nitrogen recovery with a 30-minute treatment of synthetic fresh urine. The nitrogen recovery process developed in this work can serve as a sustainable and efficient nutrient management that is suitable for decentralized wastewater treatment. This work also provides a new perspective of implementing versatile advanced materials for water and wastewater treatment.

The liquid phase of 4,4'-trimethylenedipiperidine: a safe and greener dual-task agent for clean and facile synthesis of coumarin derivatives.

A practical and facile synthesis of various coumarin derivatives was conducted using a liquid phase of 4,4'-trimethylenedipiperidine as a safe and greener dual-task reagent under catalyst-free and solvent-free conditions. This reagent is a commercially available solid and can be handled easily, having a liquid phase over a vast temperature range, high thermal stability, low toxicity, and good solubility in green solvents such as water and ethanol. It is worth mentioning that 4,4'-trimethylenedipiperidine could be completely recovered and regenerated after a simple process. The current method has other merits, including (a) minimizing the use of high-risk and toxic reagents and solvents; (b) the use of a secure and recoverable medium-organocatalyst instead of metal-based catalysts, (c) avoid tedious processes, harsh conditions, and a multi-step process for the preparation of catalysts, (d) transform phenol and salicyladehyde derivatives into the corresponding coumarin derivatives in good to high yields, (e) minimize hazardous waste generation. TMDP could be easily recovered and reused several times with no change in its activity. Furthermore, the current work demonstrated that the liquid phase of 4,4'-trimethylenedipiperidine can be a promising medium in organic reaction at higher temperatures due to its broad liquid range temperature, thermal stability, acceptor/donor hydrogen bond property, and other unique merits. New methodology for the synthesis of coumarines using liquid phase of TMDP under mild conditions.

New Bio-Based Furanic Materials Effectively Absorb Metals from Water and Exert Antimicrobial Activity.

Development of sustainable bio-based materials for removal of toxic contaminants from water is a high priority goal. Novel bio-based binary and ternary copolymers with enhanced ion-exchange, adsorption and antibacterial properties were obtained by using plant biomass-derived diallyl esters of furandicarboxylic acid (FDCA) as crosslinking agents and easily available vinyl monomers. The synthesized copolymer materials showed higher sorption capacities for NiII , CoII and CuII compared to the commercial ion-exchange resins, and they maintained their high metal adsorption capacities for over 10 cycles of regeneration. The synthesized copolymer gels containing 1-5 wt % of the crosslinker showed excellent water absorption capacities. The synthesized copolymers with 1 % crosslinker content showed swelling ratios high enough to also act as moisture absorbents. Synthesized copolymers with crosslinker content of 10 wt % performed as contact-active antibacterials by inhibiting the growth of Gram-positive (S. aureus) and Gram-negative bacteria (E. coli, K. pneumonia) in suspension tests.

Engineered pro-peptide enhances the catalytic activity of keratinase to improve the conversion ability of feather waste.

Keratinase is an attractive industrial enzyme that can specifically catalyze keratin waste to obtain value-added products. A challenge to the application of keratinase is improving catalytic capacity to achieve efficient hydrolysis. In this study, we effectively expressed the keratinase gene from Bacillus licheniformis BBE11-1 in Bacillus subtilis WB600 based on pro-peptide engineering. Partial deletion of the pro-peptide sequence and the substitution of amino acid at the pro-peptide cleavage site (P1) suggested that the "chaperone effect" and "cleavage efficiency" of the pro-peptide determine the activity of the mature enzyme. Subsequently, seven target sites that can increase the activity of the mature enzyme by 16%-66% were obtained through the multiple sequence alignment of pro-peptides and site-directed mutation. We further performed combinatorial mutations at six sites based on the design principle of three-codon saturation mutations and obtained mutant 2-D12 (236.8 KU/mg) with a mature enzyme activity of 186% of the original (127.6 KU/mg). Finally, continuous fermentation was carried out in a 5-L bioreactor for 22 h, and the activity of the 2-D12 mature enzyme was increased to 391.6 KU/mg. Most importantly, 2-D12 could degrade more than 90% of feather waste into amino acids and peptides within 12 h with the aid of sulfite.

Application of nitrogen-rich porous organic polymer for the solid-phase synthesis of 2-amino-4H-benzo[b]pyran scaffolds using ball milling process.

This paper presents the efficient synthesis of 2-amino-4H-benzo[b]pyrans using mesoporous poly-melamine-formaldehyde as a polymeric heterogeneous catalyst. According to the principals of green chemistry, the reaction was performed by the planetary ball milling process at ambient and neat conditions. The heterogeneous catalyst could be reused up to five runs with no reducing of catalytic efficiency. A variety of substituted 2-amino-4H-benzo[b]pyrans were obtained in good to excellent yields under eco-friendly conditions. Other advantages of the current methodology include short reaction time, wide substrate-scope, and use of a metal-free polymeric catalyst. Also, the current method avoids the use of hazardous reagents and solvents, tedious workup and multi-step purification. This work revealed that porous organic polymers containing Lewis base sites having acceptor-donner hydrogen bonding functional groups, and high porosity could play a vital role in the promotion of the one-pot multicomponent reactions in the solid-phase synthesis.

School canteens and the food waste challenge: Which public initiatives can help?

Foodservice is estimated to produce 12% of the total food waste in Europe, and it is a major target for policies against food waste. The amount of food lost during foodservice operations has been assessed in the literature as a figure ranging from 10% to 41% of the quantity prepared in the kitchen, either as non-served food or as plate waste. In this paper, a systematization of the current initiatives against food waste in EU school foodservice is provided. This background is used as a base to discuss the results of a direct assessment of food waste conducted in 78 primary schools in Italy, where 28.6% of the food prepared was not consumed by the diners. Part of it was saved for reuse, while the rest was disposed and treated as organic waste or, to a lesser extent, as unsorted waste. The flows of food waste, represented by a Sankey diagram, show that some actions may be implemented in order to save more food from disposal; for example, implementing donation programmes for non-served food or using doggy bags to avoid the disposal of plate waste. A greater effort shall be put on preventive actions, aimed at avoiding the generation of food waste; in this sense regular monitoring at schools may act as a first preventive measure as it can increase the awareness of students, teachers and foodservice staff over the issue of food waste.

Influencing factors of community empowerment for domestic waste prevention and management among people living in river basin: A scoping review.

Citarum River in West Java, Indonesia, is the most polluted river in the world which pollutes the ocean. This is caused by lack of community empowerment for domestic waste prevention and management. This study aimed to identify factors influencing community empowerment for domestic waste prevention and management, as well as the intervention for improvement. A scoping review was conducted using databases such as Google Scholar, EBSCOhost, and PubMed with keywords such as community empowerment, domestic waste management, waste prevention, and healthy living, published from 2009 to 2019. Initially, a total of 57,339 articles were retrieved, and with inclusion and exclusion criteria, eight articles were included for this review. Based on the results, three influencing factors were found at the individual, community, and government level. Regarding the intervention, promoting people and participatory engagement were the most effective ways to empower people in promoting healthy and clean behavior. Further research is needed to improve community empowerment for waste management among people living in the river basin to reduce pollution from domestic waste.

No time to waste: assessing the performance of food waste prevention actions.

As a result of the growing awareness of the need to prevent food waste, several initiatives have been launched in the last few years to reduce food waste generated across the food supply chain. However, the evaluation of food waste prevention interventions is still at an early stage of development and appropriate methods to assess their effectiveness are missing, hampering the identification of best practices amongst existing initiatives and the prioritisation of those that are most promising. To address such needs and provide a common approach to consistently assess the performance of food waste prevention initiatives, the European Commission Joint Research Centre has developed an evaluation framework for food waste prevention actions. The framework supports the EU Platform on Food Losses and Food Waste, which has been established to identify best practices and share knowledge on food waste prevention initiatives. Additionally, a food waste prevention calculator, based on life cycle thinking, has been developed to support such an evaluation by a consistent assessment of the environmental and economic benefits of such initiatives, and the identification of potential trade-offs at early design stages. The main goal of this paper is to present the evaluation framework and the calculator developed, critically discussing how future initiatives should be designed, monitored and reported, to ensure sufficient and relevant data is made available to enable their proper assessment. Crucially, this would enable practitioners and decision makers to evaluate the success of existing initiatives and give priority to the implementation of the best performing ones.

Municipal solid waste prevention: A review of market-based instruments in six European Union countries.

This article focuses on quantitative prevention of municipal solid waste among the 28 member countries of the European Union. A strict definition of waste prevention is used, including waste avoidance, waste reduction at source or in process, and product reuse, while recycling is outside the scope of this article. In order to provide a solid overview of the European situation, the study selected six countries (Belgium, Bulgaria, Italy, the Netherlands, Romania and Spain). Several selection requirements have been considered, such as geographic location or municipal solid waste per capita production trends from 1995 to 2017. A review of prevention programmes and other national strategic documents has been conducted. Extended producer responsibility, Pay-As-You-Throw schemes, Deposit-Refund Systems and Environmental Taxes implementation among the selected countries have been studied in order to understand how these market-based instruments can be used for the sake of waste prevention. Each market-based instrument has been further analysed using the Drivers Pressures State Impact Response model. Based on the results of this study, the effectiveness of market-based instruments implementation is strictly related to the context they are enforced in. It is particularly important to tailor the market-based instruments based on the implementation area. Nevertheless, market-based instruments, which are now mostly meant to boost the recycling sector of the considered Member States, should be designed to improve waste prevention performances, ensuring the achievement of the highest level of waste hierarchy promoted by the European Union.

Seven-Step Continuous Flow Synthesis of Linezolid Without Intermediate Purification.

Herein, the blockbuster antibacterial drug linezolid is synthesized from simple starting blocks by a convergent continuous flow sequence involving seven (7) chemical transformations. This is the highest total number of distinct reaction steps ever performed in continuous flow without conducting solvent exchanges or intermediate purification. Linezolid was obtained in 73 % isolated yield in a total residence time of 27 minutes, corresponding to a throughput of 816 mg h-1 .

New York City's Reuse Impact Calculator: Quantifying the zero waste impact of materials reuse.

In 2015, the city of New York (NYC) introduced a plan to reduce the volume of collected solid waste by 90% by 2030 and envisioned the expansion of reuse opportunities as one of its main drivers. The assessment of the contributions from reuse initiatives to the advancement of waste prevention and waste reduction goals requires a quantitative understanding of the scope of reuse activities. The high population density in NYC and well-organised collection efforts by The City of New York Department of Sanitation (DSNY) (DSNY) have resulted in a structure that enables the informal sector to readily contribute and access the reuse market. Importantly, the scale of the operations in NYC enable the results found to be a model for other municipalities of similar size. This article presents the Reuse Impact Calculator, developed from the need to automate and quantify the environmental impact of product reuse by nonprofit enterprises in NYC. Specifically, we will explain the development process, show the novel characteristics of this calculator, describe the software in terms of data input, auto mapping functionality and calculations and present a case study to demonstrate the implementation of the Reuse Impact Calculator. This calculator is a dynamic and easily modifiable tool that converts diverse datasets to comparable conditions and allows the assessment of the impact of reuse organisations to waste prevention in NYC.

Structured evaluation of food loss and waste prevention and avoidable impacts: A simplified method.

Interest in life-cycle assessment (LCA) for foodstuffs has increased over recent years. In the same period, there could also be noticed an increased focus on food losses and waste (FLW); hence the need for guidance or a method that assesses the environmental impacts of FLW when analyzing agrifood systems with the use of LCA. This study introduces a method of assessing FLW in the context of supply chain LCA through: i) calculating the impacts of the food supply chain with the associated FLW, in order to account for the overall environmental impacts; and ii) assessing the benefits of FLW prevention strategies. After the method is presented, a practical application follows. The results of this study show that this method is able to aid LCA practitioners to include FLW on their LCA for food studies so as not to underestimate the impacts. Furthermore, the method is able to aid decision makers to assess the benefits of implementing a FLW prevention action in comparison to a baseline scenario. This method has some limitations: the attributional approach, lack of guidelines on how to estimate prevention potentials, as well as lack of guidelines to estimate additional impacts due to prevention actions.

Borazine-CF3- Adducts for Rapid, Room Temperature, and Broad Scope Trifluoromethylation.

A fluoroform-derived borazine CF3- transfer reagent is used to effect rapid nucleophilic reactions in the absence of additives, within minutes at 25 °C. Inorganic electrophiles spanning seven groups of the periodic table can be trifluoromethylated in high yield, including transition metals used for catalytic trifluoromethylation. Organic electrophiles included (hetero)arenes, enabling C-H and C-X trifluoromethylation reactions. Mechanistic analysis supports a dissociative mechanism for CF3- transfer, and cation modification afforded a reagent with enhanced stability.

Fast determination of codeine, orphenadrine, promethazine, scopolamine, tramadol, and paracetamol in pharmaceutical formulations by capillary electrophoresis.

Paracetamol is an active ingredient commonly found in pharmaceutical formulations in combination with one of the following compounds: codeine, orphenadrine, promethazine, scopolamine, and tramadol. In this work, we propose a unique analytical method for determination of these active ingredients in pharmaceutical samples. The method is based on capillary electrophoresis with capacitively coupled contactless conductivity detection. The separation was achieved on a fused silica capillary (50 cm total length, 40 cm effective length, and 50 µm id) using an optimized background electrolyte composed of 20 mmol/L ß-alanine/4 mmol/L sodium chloride/4 µmol/L sodium hydroxide (pH 9.6). Each sample can be analyzed in a single run (≤2 min) and the limits of detection were 2.5, 0.62, 0.63, 2.5, 15, and 1.6 µmol/L for scopolamine, tramadol, orphenadrine, promethazine, codeine, and paracetamol, respectively. Recovery values for spiked samples were between 94 and 104%.

Extending the life-cycle of reverse osmosis membranes: A review.

The reverse osmosis (RO) technology for desalination and demineralization serves the global water crisis context, both technically and economically, and its market is growing. However, RO membranes have a limited life-cycle and are often disposed of in landfills. The impacts caused by the disposal of thousands of tonnes per annum of RO membranes have grown dramatically around the world. Waste prevention should have a high priority and take effect before the end-of-life phase of a product is reached. In this review, a summary is presented of the main advances in the performance of the RO technology and the membrane lifespan. Afterwards, this paper reviews the most important relevant literature and summarizes the key findings of the research on reusing and recycling the discarded modules for the purpose of extending the life-cycle of the RO membranes. In addtion, there are some recent researches that indicated recycling RO membranes for use by the microfiltration or ultrafiltration separation processes is a promising solution to the disposal problem. However, there are many gaps and differences in procedures and results. This article also discusses and brings to light key parameters involved and controversies about oxidative treatment of discarded RO membranes.