Low collection coverage, lack of a safe and appropriate destination for all generated waste and pollution caused by inadequate waste disposal procedures are probably one of the most significant ...threats in the current decade (2021-2030). At the beginning of 2020, a new and unforeseen challenge emerged - the COVID-19 pandemic. This article provides a brief overview of the state of waste management in the world, identifying significant challenges that arose during the pandemic. As the situation changed daily in all regions of the world, many local authorities were obliged to react urgently and adjust the current way of waste management. People's habits have changed and the mandatory wearing of protective masks has increased the daily amount of plastic waste worldwide by approximately 21 000+ tons. This represented an additional burden for already under capacitated waste management systems. Also, waste collected from households in many parts of the world had to be treated as medical waste due to the COVID-19 positive people. There was a drastic increase in the daily amount of generated medical waste due to this, which in some cases was up to 6 times higher than usual.
Excessive use of fossil fuels has an extremely negative impact on the environment and climate, as it results in the emission of harmful gases into the atmosphere. The goal of this research was to ...compare the use of solar energy and biomass as an energy source for drying tobacco in relation to natural gas. The research covered the drying of Virginia tobacco leaves with batch dryers, namely: thermogen models that use wood chips ("Model 1"), firewood ("Model 2") and pellets ("Model 3"), one model with natural gas thermogen combined with solar cells ("Model 4") and one thermogen with classic tobacco drying with ground gas ("Model 5"). In the first and third drying phase "Model 1" provides enough energy for drying the tobacco leaf but in the second phase it could not provide the required temperature, so it is necessary to increase the capacity of the combustion chamber. "Model 2" fully meets the requirements of tobacco leaf drying technology. Using pellets according to "Model 3" there were no difficulties and the tobacco was dried with good quality. Energy saving by using solar collectors according to "Model 4" is about 20%. Natural gas drying showed as the most expensive one.
The simulation results of sunflower seeding in the laboratory with seed plates from 12 to 36 holes at working speeds from 4 to 10 km/h are presented. At a working speed of 6 km/h, the seed plate n = ...12 with a rotational speed of 0.652 m/s achieved an average seeding spacing of 23.26 cm. At this rotational speed, the plate achieved a QFI of 89.15. The seed plate n = 36 with a rotational speed of 0.217 m/s achieved an average spacing of 21.76 cm with a QFI index of 98.45. At a working speed of 10 km/h, the seeding machine achieved an average spacing of 23.87 cm with a seed plate n = 12. The same seed plate achieved a rotational speed of 1.812 m/s. The seed plate n = 36 with a rotational speed of 0.602 m/s recorded an average spacing in the seeding simulation of 22.52 cm.
Water, food, and energy are considered necessary segments to achieve the sustainable development goals. Urbanization, population growth, international trade, economic development and climate change ...will significantly increase the need for these three segments, which is why it is necessary to focus on equal access to water, food and energy, while adhering to the principles of the circular economy. Water is used along the entire agri-food chain, while the generated energy is needed for the production, transport and distribution of food, as well as for the extraction, pumping, lifting, collection, transport, and treatment of water. Urbanization, industrial development, and the general population of citizens also require gradually more water, as well as land for food production and expansion, which entails the need for more and more energy resources. This results in environmental degradation and impairment of environmental sustainability, which leads to the scarcity of resources and impairment of the health of living organisms. Given the importance of the topic related to the knowledge of biowaste and its management, a survey was conducted to gain insight into whether the general population of citizens is aware that by throwing food, other resources represented in the "water-energy" chain also get wasted, which leads to the disturbance of ecological stability. As expected, the results showed that our society needs further education to be able to manage waste in a sustainable way.
A significant problem in the use of pumpkin is the fact that its total mass is not used completely, but is thrown away and becomes waste. The meat is used for the production of flour, but after its ...production there are leftovers. The work includes two varieties of pumpkin (seed with shell and seed without shell). The aim of this study is to determine the impact of drying and variety on the quality of meat flour and the possibility of using residues after the production of peel and seed shells with the goal of producing energy. Drying will be carried out by convection at 50, 60, and 70 °C. The obtained results showed that Variety 1 (with shell) is better for flour production and energy efficiency. LHV of peel was 14.70 MJ/kg and shell 17.80 MJ/kg and classifies pumpkin residues as a very desirable raw material for green energy production.
Cilj ovoga rada bio je utvrditi učinak gnojidbe dušikom (N) od 30 odnosno od 45 kg/ha, kao i trima komercijalnim dušičnim gnojivima, CaNO3 (15% N), KAN (27% N) i YaraMilaTM Cropcare (8:11:23), na ...agronomska svojstva: prinos, cijenu i vrijednost suhoga lista, kao i na šest morfoloških svojstava duhana tipa virdžinija. U poljski pokus, proveden u četiri okoline, bila su uključena tri hrvatska kultivara duhana. Gnojidba dušikom imala je signifikantan učinak samo na komponente prinosa: duljinu, širinu i površinu 9. lista, čije su vrijednosti kod gnojidbe s 45 kg N/ha bile za 2,2; 3,5 odnosno 5,8% veće u odnosu na gnojidbu s 30 kg N/ha. Tip korištenoga dušičnog gnojiva nije imao signifikantan učinak niti na jedno ispitivano svojstvo. Uzorak korelacija između morfoloških i gospodarskih svojstava bio je pod utjecajem okoline, kao i razine gnojidbe. Iako nije utvrđen učinak gnojidbe na gospodarska svojstva, signifikantno povećanje komponenata prinosa kod gnojidbe s 45 kg N/ha, u usporedbi s 30 kg N/ha, upućuje na višu razinu gnojidbe kao jamstvo osiguranja visokih i stabilnih prinosa te kvalitete osušenoga lista.
The aim of this study was to determine the effect of nitrogen (N) fertilization rate of 30 and 45 N kg/ha, as well as three commercial N fertilizers, CaNO3 (15% N), KAN (27% N) and YaraMilaTM Cropcare (8:11:23) on the agronomic traits: yield, price, and value, as well as six morphological traits of flue-cured tobacco. The field experiments, which included three Croatian tobacco cultivars, were conducted in four environments. Nitrogen fertilization had a significant effect only on yield components: length, width and area of the 9th leaf, whose values for fertilization with 45 kg N/ha were 2.2%, 3.5%, and 5.8% higher, respectively, compared to fertilization with 30 kg N/ha. The type of N fertilizer did not have a significant effect on any of the traits. The pattern of correlations between morphological and economic traits was influenced by the environment, as well as by the level of fertilization. Although no effect of fertilization level on economic traits was found, the significant increase in yield components at 45 kg N/ha compared to 30 kg N/ha suggests a higher level of fertilization as a guarantee of ensuring high and stable yields and quality of the cured leaf.
The paper presents the result of a triennial field experiment (2013‒15), aiming to determine the influence of irrigation, nitrogen fertilization, and cultivars, as well as their interactions on the ...yield and chemical properties of the soybean seeds. Four soybean cultivars (Lucija, Vita, Ika and Tena) of different maturity groups were investigate as a sub‐subplot factor (C). The main plot factor (A - irrigation) resulted in a statistically very significant (P≤0.01) seed yield in all three years, and it was found out by an analysis of variance. The subplot factor (B - nitrogen fertilization) had an impact on the grain yield depending on the research year, while sub‐subplot factor (C-cultivar) significantly affected all examined traits. The factor interactions and their significance varied by the research years. The seed yield achieved in 2013 (3883 kg ha-1) indicated a great importance of all factors’ interaction. The correlations between a seed yield and a protein and oil concentration were determined during the research.
Aim of this study was to monitor the influence of drying method (naturally and chamber drying) and different sample preparation on supercritical CO2 extraction of oil from three grape seed varieties ...(Graševina, Zweigelt, Cabernet Sauvignon). The highest oil content was obtained from naturally dried screened and washed seeds of red variety Cabernet Sauvignon (14.85%) and lowest from chamber dried screened seeds of white variety Graševina (7.67%). Peroxide value ranged from 0.36 to 1.77 mmol O2/kg oil, free fatty acids 0.28-8.0%, and insoluble impurities 0.05-0.28%. Determined fatty acids were palmitic (6.98-11.58%), stearic (3.82-6.59%), oleic (14.90-19.97%) and linoleic acid (61.82-71.96%) in oil obtained from naturally dried seeds and 6.84-8.68%, 4.12-5.73%, 15.10-20.18% and 67.88-70.76% in oil from chamber dried seeds, respectively. In defatted cakes after supercritical CO2 extraction, protein and fibre content ranged from 8.17 to 9.85% and 34.58 to 43.96%, respectively. According to ANOVA results, sample preparation and drying method had statistically significant influence on grape seed oil extraction.
Cilj istraživanja bio je odrediti utjecaj načina sušenja (prirodno i u komornome sušioniku), kao i same pripreme sjemenki grožđa, na ekstrakciju ulja superkritičnim CO2 iz triju sorata grožđa (graševina, Zweigelt, Cabernet Sauvignon). Najveći udio ulja ekstrahiran je iz prirodno osušenih i prethodno opranih sjemenki grožđa crne sorte Cabernet Sauvignon (14,85%), dok je najmanje ulja dobiveno iz sjemenki osušenih u komornome sušioniku bijele sorte graševina (7,67%). Vrijednost peroksidnoga broja dobivenih ulja bila je u rasponu 0,36-1,77 mmol O2/kg, slobodne masne kiseline 0,28-8,0%, a netopljive nečistoće 0,05-0,28%. U ulju dobivenome iz prirodno osušenih sjemenki grožđa određene su sljedeće masne kiseline: palmitinska (6,98-11,58%), stearinska (3,82-6,59%), oleinska (14,90-19,97%) i linolna kiselina (61,82-71,96%). U ulju sjemenki grožđa prethodno osušenih u komori određene su sljedeće masne kiseline: palmitinska (6,84-8,68%), stearinska (4,12-5,73%), oleinska (15,10-20,18%) i linolna kiselina (67,88-70,76%). Nakon ekstrakcije superkritičnim CO2 u odmašćenim pogačama određen je udio proteina (8,17-9,85%) i vlakana (34,58-43,96%). Priprema uzorka i način sušenja sjemenki grožđa te sorta imaju značajan utjecaj na ekstrakciju i kvalitetu dobivenoga ulja.
Spelt (Triticum spelta L.), also known as dinkel wheat, or hulled wheat is one of the oldest crops. It originates from Asia. In Europe spelt was very important cereal during the Bronze Age and the ...Middle Ages. After the processing grains for food, biomass lags as a by-product or waste. Rising fossil fuel prices and increasing concerns about climate change are creating a growing demand for new sources of raw material for biomass combustion for sustainable heat production. In recent years studies have shown the positive effects of the use of agricultural residues for energy production. Grains of Spelt are processed into various purposes, while the chaff, glumes and stems remain as a by-product. Therefore, it is important to carry out research in order to determine energy characteristics of chaff, glumes and stems. This paper examined the two Spelt varieties: BcVigor and Ostro. Collected and homogenized samples were analysed by the energy characteristics: high (HHV) and lower (LHV) heating values of chaff, glumes and stems were determined by standard methods. The results obtained in this research showed that, after the use of Spelt grain for food, chaff, glumes and stems are representing by-product but also it is a high-quality raw material for energy production because of its high calorific values: the upper heating value in BcVigor stem was 17.367 MJ/kg and 17.224 MJ/kg in the Ostro stem, 16.402 MJ/kg in the Ostro chaff and glumes and 16.650 MJ/kg in the BcVigor chaff and glumes.
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