Integrated TOPSIS-COV approach for selecting a sustainable PET waste management technology: A case study in Qatar

A historical review and analysis on MOORA and its fuzzy extensions for different applications

Multi-criteria decision-making (MCDM) methods have been widely used among researchers to provide a trade-off solution between best and worst, considering conflicting criteria and sets of preferences. An efficient and systematic literature review of these methods is needed to maintain their application in distinctive domains. To this end, this paper presents a comprehensive and systematic literature survey on "multi-objective optimization by ratio analysis" (MOORA) method and its fuzzy extensions developed and discussed in recent years. This review includes articles categorized based on the publication name, publishing year, journal name, type of applications, and type of fuzzy extensions. In addition, this review will enhance the understanding of practitioners and decision-makers on the MOORA method, its development, fuzzy hybridization, different application areas, and future work. The study revealed that the MOORA technique was predominantly used with the TOPSIS approach, followed by the AHP and COPRAS methods. Furthermore, 76.28 % use single and hybridization approaches among all MOORA studies, while 23.72 % use MOORA in a fuzzy environment.

Municipal solid waste management: Identification and analysis of technology selection criteria using Fuzzy Delphi and Fuzzy DEMATEL technique

Municipal solid waste management (MSWM) poses a considerable challenge to developing countries like Bangladesh because of the rising waste generation rates and lack of effective management practices such as illegal open dumping and informal waste collection. One of the crucial factors in the successful management of MSW is to select the appropriate technology which is a complex multi-criteria and laborious process. Despite the global emphasis on the importance of MSWM in the literature, there is a lack of studies conducted in developing countries that effectively identify and analyze the critical performance criteria for appropriate technology selection. This research aims to address this shortcoming by identifying, and prioritizing the selection criteria and finally investigating the inter-relationship between them and the degree to which they affect or are affected by one another. First, a thorough literature review and expert consultation were employed to determine a set of 21 key criteria using the Fuzzy Delphi method (FDM). Later, taking into account the imprecise and subjective nature of the DEMATEL method on human judgements, the Fuzzy DEMATEL technique was employed to investigate the cause-effect relationships among the identified criteria. The findings of the study demonstrated that 14 criteria were categorized as causal elements that have the most significant influence on the MSWM technology selection process and 7 criteria were categorized as effect. The selection of MSWM technology demands greater consideration of the top three ranked criteria, namely T4- Access to Technology (AT), T8- Feasibility (F), and the Ec6-Infrastructure requirements (IR). By identifying the pertinent criteria, structures and interrelationships, the outcome of the study can facilitate a better understanding of causal relationships among the criteria that require specific consideration from the decision-makers and allow them to select appropriate MSW management technology.

Improvement of soil acidification and ammonium nitrogen content in tea plantations by long-term use of organic fertilizer

Soil acidification is common in some Chinese tea plantations, which seriously affected growth of tea trees. Hence, it is essential to explore soil remediation in acidified tea plantations for sustainable development of the tea industry. We sought to determine how different fertilizers affect acidified soil and their N transformation in tea plantations. Different fertilizers were used on acidified tea plantation soils for 4 years (2017-2021), and changes in soil pH, indices related to soil N transformation and tea yield were analysed to construct interaction networks of these indices and find which had the largest influence on fertilization. Long-term use of sheep manure reduced soil acidification, increased soil pH, enhanced the number and intensity of N-fixing and ammonifying bacteria, urease, protease, asparaginase and N-acetamide glucose ribosidase activity and nifH gene expression. This treatment reduced the number and intensity of soil nitrifying and denitrifying bacteria, nitrate reductase and nitrite reductase activity, while the expression of amoA-AOA, nirK, nirS, narG and nosZ in turn increased ammonium N content of the soil, reduced nitrate N content, and enhanced tea yield. Topsis index weight analysis showed that ammonium N content in the soil had the largest impact among fertilization effects. Long-term use of sheep manure was beneficial in restoring the balance of the micro-ecosystem in acidified soil. This study provides an important practical basis for soil remediation and fertilizer management in acidified tea plantation soils.

Reasonable deep application of sheep manure fertilizer to alleviate soil acidification to improve tea yield and quality

Soil acidification in Chinese tea plantations is widespread, and it has significantly affected the growth of tea trees; it was important to explore soil remediation of acidified tea plantations in depth for the sustainable development of tea industry. In this study, the effects of sheep manure fertilizer with different application depths on soil acidification, tea yield and quality, and soil nitrogen transformation in tea plantations were analyzed for five consecutive years from 2018 to 2022. The results showed that long-term use of sheep manure fertilizer significantly reduced soil acidification (P< 0.05) in tea plantations, improved soil pH and soil ammonium nitrogen content, enhanced root activity and root nitrogen uptake capacity of tea trees, and thus improved tea yield and quality. The effect of different application depths of sheep manure fertilizer on tea yield and quality was mainly reflected in the transformation ability of soil ammonium nitrogen and nitrate nitrogen, which showed that high transformation ability of soil ammonium nitrogen and high ammonium nitrogen content were beneficial to high tea yield and vice versa, and the best effect was achieved when sheep manure was applied at a depth of 50 cm and 70 cm. The topsis analysis confirmed that sheep manure fertilization had a greater effect on root activity, ammonium nitrogen, ammonia intensity, and nifH gene. This study provided an important practical basis for the restoration of acidified tea plantation soil through sheep manure fertilizer management.

Effects of Long-Term Use of Organic Fertilizer with Different Dosages on Soil Improvement, Nitrogen Transformation, Tea Yield and Quality in Acidified Tea Plantations

In this study, sheep manure fertilizers with different dosages were used for five consecutive years to treat acidified tea plantation soils, and the effects of sheep manure fertilizer on soil pH value, nitrogen transformation, and tea yield and quality were analyzed. The results showed that soil pH value showed an increasing trend after a continuous use of sheep manure fertilizer from 2018 to 2022. After the use of low dosage of sheep manure fertilizer (6 t/hm²-15 t/hm²), tea yield, the content of tea quality indicators (tea polyphenols, theanine, amino acid, and caffeine) and soil ammonium nitrogen content, ammoniating bacteria number, ammoniating intensity, urease activity and protease activity showed increasing trends and were significantly and positively correlated to soil pH value, while the related indexes showed increasing and then decreasing trends after the use of high dosage of sheep manure fertilizer (18 t/hm²). Secondly, the nitrate nitrogen content, nitrifying bacteria number, nitrifying intensity, nitrate reductase activity, and nitrite reductase activity showed decreasing trends after the use of low dosage of sheep manure fertilizer and showed significant negative correlations with soil pH value, while the related indexes showed decreasing trends after the use of high dosage of sheep manure and then increased. The results of principal component and interaction analysis showed that the effects of sheep manure fertilizers with different dosages on tea yield and quality were mainly based on the transformation ability of ammonium nitrogen and nitrate nitrogen in the soil, and the strong transformation ability of ammonium nitrogen and the high ammonium nitrogen content in the soil were conducive to the improvement of tea yield and quality, and vice versa. The results of topsis comprehensive evaluation and analysis showed that the most influential effect on the fertilization effect was the ammonium nitrogen content in the soil and long-term treatment with 15 t/hm² of sheep manure fertilizer had the highest proximity to the best fertilization effect. This study provided an important practical basis for the remediation and fertilizer management in acidified tea plantation soils.