Lignin Nanoparticles and Alginate Gel Beads: Preparation, Characterization and Removal of Methylene Blue

A novel and effective green system consisting of deep eutectic solvent (DES) was proposed to prepare lignin nanoparticles (LNPs) without any lignin modification. The LNPs are obtained through the dialysis of the kraft lignin-DES solution. The particle size distribution, Zeta potential and morphology of the LNPs are characterized by using dynamic light scattering (DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The average diameter of LNPs is in the range 123.6 to 140.7 nm, and the LNPs show good stability and dispersibility in water. The composite beads composed of LNPs and sodium alginate (SA) are highly efficient (97.1%) at removing methylene blue (MB) from the aqueous solution compared to 82.9% and 77.4% by the SA/bulk kraft lignin composite and pure SA, respectively. Overall, the LNPs-SA bio-nanocomposite with high adsorption capacity (258.5 mg/g) could be useful in improving water quality and other related applications.

Complex Systems Thinking Approach to Urban Greenery to Provide Community-Tailored Solutions and Enhance the Provision of Cultural Ecosystem Services

This paper presents a GIS-based method for supporting local administrations in the design of urban green areas while taking into account the complexity of the whole system. The proposed method merges the criteria of availability, accessibility, attractiveness, usability, and suitability in a multi-level approach (city, neighborhood green area) to assist in the selection of which services within green areas to enhance from those requested by citizens. The case study is an urban park in a medium-sized Italian city (Perugia). The results demonstrate that the available urban green spaces amount to 34.7 m2 per person, but only 24% of citizens have adequate access to a green area providing at least an adequate level of service, and 18% of them are without access to any appropriately equipped green area. Furthermore, citizens have limited knowledge of their city’s urban green system as a whole. Indeed, 41% of the requested services were already available in other accessible green areas with attractive and readily available dedicated equipment. These areas were suggested as alternative solutions. To achieve a complex systems approach, our results suggest observing similar systems with various and adaptable scales and studying them as open networks composed of heterogeneous internal and external variables.

Green System Development in the Medinas of Tunis and Marrakesh—Green Heritage and Urban Livability

Due to their authentic urban and architectural character, the Medinas of Tunis and Marrakesh became listed among the United Nations educational, scientific, and cultural organization (UNESCO) heritage sites in 1979 and 1985, respectively. Nowadays, the urbanization of the surrounding green areas and the climate change impacts on cities are degrading the Medinas’ livability and their characteristic heritage. On the other hand, scientific knowledge and data about the green system in the dense urban cores of Medinas in the Maghreb region is still not a widely apprehended theme in the scientific domain. This research objective is to initiate nature-based and sustainable solutions in these cities by demonstrating the application of the urban green infrastructure (UGI) approach. As a research methodology, an analysis of the historical green system development in the Medinas is given to highlight their tangible and intangible values. The analysis goes over three periods: first, the medieval Islamic era, then the modern period during the French colony, and the contemporary city as a unique urban landscape. Finally, the study proposes a design guideline to prove the applicability of the UGI in the given historical morphologies by implementing the retained historical values of the historic green heritage in Medinas and the aspects of the site.

Synthesis of Chitosan-Coated Silver Nanoparticle Bioconjugates and Their Antimicrobial Activity against Multidrug-Resistant Bacteria

The increase in multidrug-resistant bacteria represents a true challenge in the pharmaceutical and biomedical fields. For this reason, research on the development of new potential antibacterial strategies is essential. Here, we describe the development of a green system for the synthesis of silver nanoparticles (AgNPs) bioconjugated with chitosan. We optimized a Prunus cerasus leaf extract as a source of silver and its conversion to chitosan–silver bioconjugates (CH-AgNPs). The AgNPs and CH-AgNPs were characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy (UV–Vis), and zeta potential measurement (Z-potential). The cytotoxic activity of AgNPs and CH-AgNPs was assessed on Vero cells using the 3-[4.5-dimethylthiazol-2-yl]-2.5-diphenyltetrazolium bromide (MTT) cell proliferation assay. The antibacterial activity of AgNPs and CH-AgNPs synthesized using the green system was determined using the broth microdilution method. We evaluated the antimicrobial activity against standard ATCC and clinically isolated multisensitive (MS) and multidrug-resistant bacteria (MDR) Escherichia coli (E. coli), Enterococcus faecalis (E. faecalis), Klebsiella pneumonia (K. pneumoniae), and Staphylococcus aureus (S. aureus), using minimum inhibitory concentration (MIC) assays and the broth dilution method. The results of the antibacterial studies demonstrate that the silver chitosan bioconjugates were able to inhibit the growth of MDR strains more effectively than silver nanoparticles alone, with reduced cellular toxicity. These nanoparticles were stable in solution and had wide-spectrum antibacterial activity. The synthesis of silver and silver chitosan bioconjugates from Prunus cerasus leaf extracts may therefore serve as a simple, ecofriendly, noncytotoxic, economical, reliable, and safe method to produce antimicrobial compounds with low cytotoxicity.

Elevated Vertical-Flow Constructed Wetlands for Light Greywater Treatment

Integrated planning of urban blue–green infrastructures is crucial to strengthen urban environmental quality and mitigate negative climate change-associated effects. It implies, however, increased water demand for irrigation, wherefore greywater (wastewater excluding wastewater from toilets and urinals) can be used, yet it requires handling for safe reuse. One treatment option is the use of constructed wetlands (CW), which have thus far not been broadly applied in inner-city districts due to large area requirements. This work investigates a novel bipartite container-based vertical-flow constructed wetland (VFCW) for the treatment of light greywater (from showers and hand wash basins) and its use as irrigation water for urban facade greenery. The VFCW consists of two compartments with 2.5 m2 filter area each, filled with 75 cm zeolite-containing lava sand (0–4 mm) and 75 cm Rhine sand (0–2 mm), respectively. In short, screening has proven to be well suitable for coarse solids removal, so there is no further need to settle light greywater, which reduces overall treatment area and benefits urban application. Treated greywater complied with irrigation standards at all times, yet mixing with rainwater can help reduce salt contents, if applicable. The modular/elevated lava sand VFCW exhibited extensive nitrification, even at extremely low water temperatures, as well as mean effluent concentrations of 6.3 mg/L COD and <0.05 mg/L Ptot, which makes it a very promising treatment option for greywater. All in all, the modular/elevated design promotes urban application of VFCW as a multifunctional blue–green system that can help increase urban resilience.

Overview of the integrated efficiency of management of the green supply chain in battery industrial companies. A study of an electric motorcycle battery company in China

The introduction of green supply chain coordination management is an important strategy for battery manufacturing firms that can effectively grow the Green Industrialization Movement and encourage resource recycling. First, this paper builds a collaborative management model to analyze the efficiency of the battery manufacturing business from the internal and external supply chain, based on the supply chain principle, in order to enhance the performance of the green supply chain well. After that, this paper makes an empirical study of the productive and green system efficiency of the green supply chain of companies. Since TIANNENG is the largest electric bicycle company in China, we take it as an example here. The results show that the overall green output of Chinese industrial companies in the field of electric bicycle batteries is strong, but with obvious fluctuations. The internal green output is reasonably constant, and change requires new power; the external green performance fluctuates heavily. The findings also show that industrial battery companies can increase the level of collection and recycling of waste, improve the efficiency of recovery and reuse of residual heat, and improve the organization of the green supply chain.

Towards an Understanding of the Pre-War Landscape Transformations in the Face of Contemporary Urban Challenges on the Example of Gajowice in Wrocław

This paper discusses the results of desk and field studies conducted in the Gajowice estate in Wrocław. The aim of the paper is to identify the original assumptions of the development of areas around multifamily buildings and to examine the process of their transformation to the present day. The research hypothesis states that the used solutions would now be defined as green infrastructure or nature-based solutions. This was confirmed with the help of comparative cartographic studies. Research on the original land development of the interwar period allows for identifying the principles based not only on compositional aspects, but also the recognition of natural values in the variety of green forms used in a given area and the important role of trees with large target sizes, in addition to the principle of shaping the green system that permeates the urban tissue, creating ecological corridors and positively influencing the local climate. Thus, the historical development is in line with the contemporary postulates of climate resilient cities.

How New Food Networks Change the Urban Environment: A Case Study in the Contribution of Sustainable, Regional Food Systems to Green and Healthy Cities

More and more people worldwide live in urban areas, and these areas face many problems, of which a sustainable food provision is one. In this paper we aim to show that a transition towards more sustainable, regionally organized food systems strongly contributes to green, livable cities. The article describes a case study in the Dutch region of Arnhem–Nijmegen. Partners of a network on sustainable food in this region were interviewed on how they expect the food system to develop, and in design studies possible futures are explored. Both the interviews and the designs give support to the idea that indeed sustainable food systems can be developed to contribute to green livable cities. They show that the quality and meaning of existing green areas can be raised; new areas can be added to a public green system, and connections with green surroundings are enforced. They also show that inhabitants or consumers can be stimulated to become so called food citizens, highlighting that the relation of food systems and livable cities is a very close one.