Determination of soil quality index in areas with high erosion risk and usability in watershed rehabilitation applications

Erosion is an important environmental issue threatening natural resources and ecosystems, especially soil and water. Soil losses occur in many parts of the world due to erosion at different degrees, and various rehabilitation plans have been carried out to reduce these losses. However, soil protection applications are generally carried out by considering only the essential characteristics of the soil. This may decrease the chance of success of rehabilitation applications. The present study aimed to determine the soil quality index (SQI) by weighting the soil quality parameters according to the analytical hierarchy process (AHP) in the Çapakçur microcatchment (Bingöl, Türkiye) where soil loss is high. Accordingly, 428 soil samples were taken from the study area and analyzed. The soil losses in the Çapakçur watershed were calculated employing the revised universal soil loss equation (RUSLE). To determine the soil quality index, a total of 20 indicators were used, including (i) physical soil properties, (ii) chemical soil properties, and (iii) soil nutrient content. Soil quality index results are divided into classes between 1 and 5. As a result of the study, the annual total amount of soil lost from the microcatchment was calculated as 96,915.20 tons, and the yearly average amount of soil lost from the unit area was calculated as 10.14 tons ha^-1. According to SQI, the largest area in the microcatchment was Class-2 (weak), with 39.49%, whereas the smallest area was 1.4% (the most suitable). However, it was determined that there was a significant negative relationship between SQI and soil erodibility. Considering the SQI distribution of the area in the planning of soil protection and erosion prevention practices in watershed rehabilitation studies may increase success.

Production and characterization of biodegradable bi-layer films from poly(lactic) acid and zein

Recently, packaging industry has turned to biodegradable packaging, and poly(lactic acid) has become the most remarkable polymer. However, the high oxygen permeability of PLA films significantly limits their use. Therefore, this study, it was aimed to improve the oxygen barrier properties of PLA films without adversely affecting the mechanical and water vapor barrier properties. Biodegradable PLA-Zein bi-layer films were produced by changing PLA and zein thickness. Transparent and UV barrier bi-layer films were obtained. Mechanical properties of PLA films were improved by the production of bi-layer films. Water vapor permeability of bi-layer films increased whereas the permeance decreased with zein coating of PLA. Multi-criteria decision hierarchy was used to select the best bi-layer films based on mechanical, permeance, and opacity results. Oxygen barrier properties of PLA film significantly improved by zein coating, and hydrophobicity of PLA film was not affected by zein coating. The crystallization and melting temperatures of films decreased when compared to PLA films, supporting the mechanical results. Homogeneous, non-porous, and smooth film surface was obtained and zein layer was in good compatibility with PLA layer. These results suggest that zein coatings could be used to decrease oxygen permeability of PLA films without negatively affecting other properties.

An approach to the design of photovoltaic noise barriers and a case study from Istanbul, Turkey

Solar energy solutions that do not require additional space are critical. Noise barriers, which are built in low-value lands next to noise sources, provide effective areas for PV modules. There are many studies on using noise barriers as a sub-structure for photovoltaic systems, providing electricity generation besides noise reduction targets. Photovoltaic noise barrier (PVNB) technology combines noise control measures with renewable energy generation. In this study, it is aimed to develop an integrated design method that embeds solar energy technology in noise protection structures. The method is exemplified in an existing settlement located on the side of the road with heavy traffic. According to local climate and solar data, optimum tilt angles have been determined for annual, semi-annual, seasonal, and monthly periods. Noise barrier alternatives are derived with combinations of different diffraction edge sizes of barrier top and determined optimum inclination angles. The performance of the criteria that affect the PVNB effectiveness for alternatives was calculated through software tools. The energy generation potential of PVNB and its shading in adjacent blocks were calculated with PVsyst 6.7.7. The noise control efficiency of the structure was computed via SoundPLAN 7.2. TOPSIS method, one of the most common multi-criteria decision-making (MCDM) techniques, was used in the evaluation. As a result of TOPSIS, the best PVNB solution in the case study is the alternative that has 3-m and 2-m-wide edges and 58° and 31° tilted edges. In comparison with the current situation, the selected alternative will decrease 44% of the number of receiving points affected by noise and provide 524,804 kWh annual electricity generation.

Towards a sustainable waste-to-energy pathway to pequi biomass residues: Biochar, syngas, and biodiesel analysis

The waste-to-energy (WTE) valorization pathway of Caryocar brasiliense (pequi) seeds was investigated via pyrolysis, gasification, and transesterification to understand its potential as biochar, syngas, and biodiesel. First, the pyrolysis (300-700 °C) was conducted in N₂ atmosphere for pequi seeds (PS) and pequi seeds without its extractives (PSWE), characterizing its biochar properties. The PSWE was then gasified at 1000 °C under O₂/N₂, O₂/CO₂/N₂ and O₂/H₂O/N₂ atmospheres to evaluate the characteristics of the producer gas. The PS extractives were then transesterified and characterized for biodiesel production. Finally, a multiple-criteria decision analysis assessed the PS products' potential within the thermochemical routes. The results evidenced better biochar (up to 22.29% HHV enhancement, higher mass and energy yield, up to 75.9 and 85.5% reduction of O/C and H/C, respectively, and enriched N content) via PSWE pyrolysis than PS considering biofuel application and optimistic perceptions for soil amendment. This indicates that the preceding extraction of vegetal fat from PS strengthens the WTE by including further processing of extracted oil. The produced syngas under O₂/H₂O/N₂ gasification atmosphere showed better applicability as a biofuel (16.37 MJ·kg^-1 lower heating value, 107.33% cold gas efficiency, and 113.55% carbon conversion efficiency) with up to 24% higher success rate. The transesterification of the extractives revealed its potential (98% conversion rate) for use as feedstock for in situ power generation, or blended for biodiesel production. The results provide insights into the circular economy in agro-extractivist communities that may support Brazil's small and medium agro-food industries with their energy demands.

Comparative study on air gasification of plastic waste and conventional biomass based on coupling of AHP/TOPSIS multi-criteria decision analysis

A broad range of conventional biomass and plastic waste types was considered and their air gasification process was modeled using a Gibbs free energy minimization coupled with Lagrange multiplier approach. The comparison between the performances of biomass and plastic waste gasification is the main issue of this study. Another important novelty and contribution of this study is analytical hierarchy process/technique for order performance by similarity to the ideal solution coupled method that is employed in gasification of conventional biomass and plastic waste, to prioritize the considered criteria and to select the best feedstock for gasification. Hydrogen production was linearly reduced in the case of conventional biomass with an in increase in the equivalence ratio; however, there was an optimum equivalence ratio to achieve the highest hydrogen production in plastic waste gasification. Plastic waste had a higher low heating value compared to conventional biomass. However, carbon monoxide and nitrogen production from conventional biomass was smaller than from plastic waste. Ten types of feedstock, comprising six types of conventional biomass and four types of plastic waste, were selected as alternatives. The multi-criteria decision analysis coupled method revealed that waste polypropylene and polyethylene were the best alternatives.

Upgrading current multi-attribute decision-making with a 3-dimensional decision matrix for future-based decisions

Two shortcomings of existing Multi-Attribute Decision-Making (MADM) approaches are presented in this paper. The problems were decision makers' (experts') dynamic level of experience in certain areas, as well as the difficulties of forecasting the future with the existing MADM techniques. A solution is also proposed to overcome the issues.•Two critical shortcomings of existing multi-attribute decision-making (MADM) approaches are presented with this work.•As a solution for the shortcomings, a 3-dimensional decision matrix is introduced.