Soil carbon storage under different types of arid land use in Algeria.

This study aims to assess the amount of organic carbon stored in soils, as it is an intention of knowing the sustainable soil management, by using two common methods for determining soil organic matter (SOM), namely oxidation with acidified wet dichromate (Walkley-Black method-WB) and loss on ignition (LOI). The study was carried with soil samples collected from a depth of 0 to 30 cm in the Saharan arid region of Ghardaïa (Algeria), with different land uses: agricultural, forest and pastoral. The results obtained from the LOI and WB methods were subjected to statistical analysis, and the relations between both methods were tested to investigate their relationship. The mean percentage of SOM values were 1.86, 2.42, 1.54 by using LOI, but, lower values of 0.34, 0.33, 0.36 were determined by using WB method, for agricultural, forest and pastoral soils respectively. A weak linear relationship between the two analytical procedures was obtained (R2 of 0.19 and 0.13 for agricultural and forest soils), while a medium relationship (R2 = 0.65) was found for pastoral soils when using linear adjustment. However, the opposite behaviour was found when we use the logarithmic adjustment. The study outcomes indicated discrepancies in the measurements of SOM values between the two methods, been higher those estimated with LOI. Finally, in order to identify the best methodology to measure soil organic matter in arid soils, more research is required in these extreme arid regions as they are a gap in world soil organic matter maps.

The concept of food waste and food loss prevention and measuring tools.

Food waste (FW) has become a global concern, with an estimated 1.3 billion tonnes lost annually, costing about $1 trillion. Environmental and social consequences of FW are significant, contributing to 6% of European Unions' greenhouse gasemissions and affecting global food security. FW occurs is a complex issue occurring at various stages of the food supply chain (FSC) and is influenced by multiple factors such as infrastructure, available knowledge and socio-economic conditions. Developed countries FW is more prevalent at the consumption stage, whereas in the developing countries losses occur in agricultural production, post-harvest and distribution stage. Accurate quantification of FW across the supply chain is crucial and monitoring key performance indicators helps identify areas for improvement. The European Union mandates FW measurement, aligning with sustainable development goals, emphasizing the need for effective waste prevention measures. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach was utilized to conduct a systematic literature review on FW key performance indicators (KPIs) and monitoring tools. The research identified 22 KPIs, categorized into three levels of the FSC: primary, secondary and tertiary. The most common KPIs included FW per capita, FW per portion and FW percentage. The study further discusses FW prevention measures and essential monitoring tools for addressing FW throughout the supply chain.

Waste metrics in the framework of circular economy.

There are several sustainability issues that the linear economy of today's society cannot adequately tackle (i.e. resource depletion, waste treatment, etc.). As a result, the scientific community and policymakers give high priority to the implementation of the circular economy concept. The sustainable development goals of the United Nations are in line with the European Union's (EU) commitment to a smooth transition to a circular economy. Circular business models require a shift in technical elements involving R strategies to replace traditional business models (i.e. reuse, reduce, recycle, etc.). Monitoring circular economy to provide quantifiable, measurable data is necessary for a successful transition. Monitoring tools (i.e. Key Performance Indicators, quality protocols) enable decision-makers to measure circular economy performance and identify circularity's advantages and disadvantages. To stimulate the adoption of a circularity model addressing critical issues of excessive waste production and resource use, this mini review aims to address the literature gap of waste metrics in the framework of circular economy and offer insights on circular economy indicators to aid for a seamless transition to a more sustainable society. For this purpose, Preferred Reporting Items for Systematic Reviews and Meta-Analysis method was chosen to assess literature. The authors collected and analysed data from 101 records, 70 articles and 31 reports related to the topic under consideration. Through the literature review, it is obvious that moving away from linear production model frequently leads to the development of new internal capabilities along the value chain and, eventually, high efficiency that reduces costs, increasing productivity, encourages brand names, minimizes threats, creates new products and fulfils regulations and green consumer expectations.

Nitrogen management in farming systems under the use of agricultural wastes and circular economy.

Population growth leads to an increase in the demand for energy, water, and food as cities grow and urbanize. However, the Earth's limited resources are unable to meet these rising demands. Modern farming practices increase productivity, but waste resources and consume too much energy. Agricultural activities occupy 50 % of all habitable land. After a rise of 80 % in 2021, fertilizer prices have increased by nearly 30 % in 2022, representing a significant cost for farmers. Sustainable and organic farming has the potential to reduce the use of inorganic fertilizers and increase the utilization of organic residues as a nitrogen (N) source for plant nutrition. Agricultural management typically prioritizes nutrient cycling and supply for crop growth, whereas the mineralization of added biomass regulates crop nutrient supply and CO2 emissions. To reduce overconsumption of natural resources and environmental damage, the current economic model of "take-make-use-dispose" must be replaced by "prevention-reuse-remake-recycle". The circular economy model is promising for preserving natural resources and providing sustainable, restorative, and regenerative farming. Technosols and organic wastes can improve food security, ecosystem services, the availability of arable land, and human health. This study intends to investigate the nitrogen nutrition provided by organic wastes to agricultural systems, reviewing the current state of knowledge and demonstrating how common organic wastes can be utilized to promote sustainable farming management. Nine waste residues were selected to promote sustainability in farming based on circular economy and zero waste criteria. Using standard methods, their water content, organic matter, total organic carbon, Kjeldahl nitrogen, and ammonium levels were determined, along with their potential to improve soil fertility via N supply and technosol formulation. 10 % to 15 % of organic waste was mineralized and analysed during a six-month cultivation cycle. Through the results, the combination of organic and inorganic fertilization to increase crop yield is recommended, as is the search for realistic and practical methods of dealing with massive amounts of organic residues within the context of a circular economy.

Environmental factors influencing DDT-DDE spatial distribution in an agricultural drainage system determined by using machine learning techniques.

The presence and persistence of pesticides in the environment are environmental problems of great concern due to the health implications for humans and wildlife. The persistence of DDT-DDE in a Mediterranean coastal plain where pesticides were widely used and were banned decades ago is the aim of this study. Different sources of analytical information from water and soil analysis and topography and geographical variables were combined with the purpose of analyzing which environmental factors are more likely to condition the spatial distribution of DDT-DDE in the drainage watercourses of the area. An approach combining machine learning techniques, such as Random Forest and Mutual Information (MI), for classifying DDT-DDE concentration levels based on other environmental predictive variables was applied. In addition, classification procedure was iteratively performed with different training/validation partitions in order to extract the most informative parameters denoted by the highest MI scores and larger accuracy assessment metrics. Distance to drain canals, soil electrical conductivity, and soil sand texture fraction were the most informative environmental variables for predicting DDT-DDE water concentration clusters.

The perception of circular economy in the framework of fashion industry.

Humanity's three main components are energy, food and clothing. Each of us, individually and collectively, contributes to climate change and CO2 emissions, natural resource consumption, and social attitudes and behaviour. Global fashion trends are expected to increase in value from 1.5 trillion dollars in 2020 to around 2.25 trillion dollars by 2025, indicating that the fashion demand is on the rise. Due to climate change, soil and water scarcity, and a variety of other diseases, new natural resources must be developed from plastic fibres, natural colours must replace synthetic ones, water consumption must be reduced and the 'buy-and-throw-away philosophy' must be replaced with 'buy-less-and-these-are-needed' and incorporate the 12 'R' strategies to aid the transition to a circular economy. In the context of waste management as well as on the development of new strategy approach, the fashion industry requires a new business circular model and furthermore a new mindset.

The Lixiviation of Metals When Amending Agricultural Soil of the Mediterranean Basin with Biosolids: Trials in Leaching Columns.

An appropriate handling and use of urban and agricultural biosolids on soils are the best means to protect them from erosion, prevent the loss of nutrients due to runoff and washing, and preserve and restore soil productivity. Heavy metal concentrations in biosolids are one of the decisive factors when using this type of waste on soil, due to potentially being harmful to crops and reaching the human food chain. There is a clear need to study the incidence of these metals in agricultural practices in Mediterranean soils. Research for this article was performed as a controlled study using leaching columns. Three treatments were performed by applying different amounts of biosolids (T50: 50,000 kg ha-1, T90: 90,000 kg ha-1, T130: 130,000 kg ha-1), as well as a blank test or control treatment (T0). The presence of macronutrients (K, Na, Ca and Mg), micronutrients (Fe, Cu, Mn and Zn) and three contaminating heavy metals (Cr, Cd and Ni) in lixiviated water was analyzed. Relevant amounts of metals in the wash water were not found. This indicates that, under the watering conditions used, the contaminants and micronutrients analyzed are not a relevant source of water contamination on a common calcareous soil of the Mediterranean Basin.

General Mapping of the Environmental Performance in Climate Change Mitigation of Spanish Universities through a Standardized Carbon Footprint Calculation Tool.

Higher education institutions (HEIs) can be considered role models of small cities that contribute to the fight against climate change. Therefore, assessing their own carbon footprints (CFs) and drawing conclusions gives significance to this study. In this study, 77 CFs from 14 HEIs were obtained through a tool developed by the Spanish Government. They were analyzed along with different variables and recalculated using the same standardized activity ratios. As a result, a general mapping of the environmental performance in climate change mitigation of Spanish universities has been obtained. Although there is an overall decrease in total CF (72.7%), direct greenhouse gas (GHG) emissions (Scope 1) remain stable, while the decrease is due to the reduction of emissions caused by electricity consumption (Scope 2) through the use electricity suppliers that guarantee the energy provided is generated from renewable sources. A lack of consensus in the definition of "student" and "employee", used for the activity ratios, causes large variations in the relative CF values. For worldwide benchmarking of HEIs' climate change performance, CF can be a valid indicator only if they: (1) include standardized Scope 1 and 2 emission sources, (2) use the same emission factors, and (3) calculate activity ratios from standardized functional units.

Soil Sealing and Hydrological Changes during the Development of the University Campus of Elche (Spain).

The University Miguel Hernández of Elche was created in 1996 and its headquarters is located in the city of Elche. A new campus was developed where new buildings and infrastructures have been established for over 25 years in the north of the city. The university is growing, and the land cover/land use is changing, adapted to the new infrastructures. In fact, the landscape changed from a periurban agricultural area mixed with other activities into an urbanized area integrated into the city. The purpose of this work was to evaluate the progressive sealing of the soil and the consequences on the surface hydrology. The area is close to the Palmeral of Elche, a landscape of date palm groves with an ancient irrigation system, which is a World Heritage Cultural Landscape recognized by UNESCO. The evolution of the land occupation was analyzed based on the Aerial National Orthophotography Plan (PNOA). Soil sealing and the modifications of the hydrological ancient irrigation system were detected. Based on the results, proposals for improvement are made in order to implement green infrastructures and landscape recovery that can alleviate the possible negative effects of the soil sealing in the area occupied by the university.

Urban strategies evaluation for waste management in coastal areas in the framework of area metabolism.

Europe is considered one of the most attractive and safe prevalent tourist destinations in the entire world. Approximately half (47.4%) of European tourist visits occurred in coastal regions, defined "on the basis of and consist of local administrative units or municipalities that border the sea, or have at least half of their total surface area within a distance of 10 km from the sea." Destinations such as Malta, Greece, Cyprus, Spain and Croatia presented with an increased level of tourist accommodation establishments, as well as, the overall flow of tourism in the European Union is mostly concentrated on Mediterranean coastal regions (as nine out 10 tourists, in 2015, spent their holidays at coastal areas). This paper, is dealing with the assessment of a tourist area and how the concept of urban metabolism has been affected by touristic activities. Moreover, this research using several key performance indicators such as waste compositional analysis, the clean coast index, the accumulation rate, and accumulation index, etc., tries to measure the level of environmental performance, and furthermore, to assess the existing infrastructures and the waste management plan, that are being implemented. The results are very useful, for any policy-maker, as well as competent authorities and/or tourist organizations which are dealing with tourist activities and aim to propose or re-schedule any waste strategy targeting the goals of United Nations Sustainable Development Goals, European Green Deal, and the new circular economy strategy.

Measuring the level of environmental performance in insular areas, through key performed indicators, in the framework of waste strategy development.

To measure "something that is not there", is not easy and at the same time not fully understandable and perceived by the citizens. Several elements (such as, waste production, waste management cost, social attitude and behaviour, etc.) interrupt and disturb any strategy in the framework of waste management. Additionally, through the European Green Deal (EGD), Europe is trying to achieve climate neutrality by 2050, taking into account the Circular Economy Strategy (CES) and the United Nations Sustainable Development Goals (UNSDGs). A Driving Force-Pressure-State-Impact-Response (DPSIR) breakdown was applied, to establish and organize key information's on the environmental performance (E.P) taking into consideration the existing pollution, reviewing the contemporary knowledge and existing implemented waste strategies on the driving forces, pressures, states and impacts. This paper includes several key performed indicators (KPIs), in order to evaluate the E.P of an area, through hybrid approach which cover among others, the waste compositional analysis, SWOT and PESTEL analysis, waste recycling and waste accumulation index, prevention activities, awareness activities etc. The results indicate that, the selected areas implement periodic measures, but they need to put more effort to boost their citizens to participate in any proposed waste strategy. Furthermore, the results are very valuable and helpful to policy makers, consultants, scientists, competent authorities, stakeholders etc., in order to design and promote synergies and activities (mainly in Local Authorities), to reach the proposed figures that EGD, proposed in relation with the CES as well as with the SDGs.

The use of wastes (organic and inorganic) in land restoration in relation to their characteristics and cost.

The great extent of degraded soils in southeast Spain makes it necessary to carry out restoration and rehabilitation strategies. In addition, the great amount of wastes produced need to be properly managed. Several types of wastes and amendments (organic and inorganic) can be applied for soil rehabilitation and land restoration. When large areas must be restored several aspects should be considered, such as availability of the waste, its characteristics, and transport. This research focuses on the characterization and the cost of 12 waste types and amendments (such as sewage sludge compost, brown peat, black peat, fertilized peat, earthworm humus, straw hay, palm tree leaves, pine bark, exfoliated vermiculite, expanded perlite, limestone outcrops, and volcanic crushed stones) obtained from four different sources. All of them were characterized following the UNE standards for soil amendments and the cost was obtained as a mean value of four different sources. The results indicate a great variability of properties between organic and inorganic materials, as was expected. Depending on the type of restoration, the characteristics, and the cost, the materials can be selected for an adequate purpose. Sewage sludge compost is a good alternative for application in large areas related to its characteristics (organic matter content and nutrient availability) and low cost. For inorganic amendments, natural limestone outcrops were the low-cost alternative. The use of both wastes (composted sewage sludge and limestone raw materials) for soil rehabilitation can facilitate the reduction of landfill disposal and add value for these wastes. Moreover, the results are very useful for scientists and engineers who deal with the development of rehabilitation and restoration strategies.

Wastewater Biosolid Composting Optimization Based on UV-VNIR Spectroscopy Monitoring.

Conventional wastewater treatment generates large amounts of organic matter-rich sludge that requires adequate treatment to avoid public health and environmental problems. The mixture of wastewater sludge and some bulking agents produces a biosolid to be composted at adequate composting facilities. The composting process is chemically and microbiologically complex and requires an adequate aeration of the biosolid (e.g., with a turner machine) for proper maturation of the compost. Adequate (near) real-time monitoring of the compost maturity process is highly difficult and the operation of composting facilities is not as automatized as other industrial processes. Spectroscopic analysis of compost samples has been successfully employed for compost maturity assessment but the preparation of the solid compost samples is difficult and time-consuming. This manuscript presents a methodology based on a combination of a less time-consuming compost sample preparation and ultraviolet, visible and short-wave near-infrared spectroscopy. Spectroscopic measurements were performed with liquid compost extract instead of solid compost samples. Partial least square (PLS) models were developed to quantify chemical fractions commonly employed for compost maturity assessment. Effective regression models were obtained for total organic matter (residual predictive deviation-RPD = 2.68), humification ratio (RPD = 2.23), total exchangeable carbon (RPD = 2.07) and total organic carbon (RPD = 1.66) with a modular and cost-effective visible and near infrared (VNIR) spectroradiometer. This combination of a less time-consuming compost sample preparation with a versatile sensor system provides an easy-to-implement, efficient and cost-effective protocol for compost maturity assessment and near-real-time monitoring.