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.
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.
Globally, lignocellulosic biomass has great potential for industrial production of materials and products, but this resource must be used in an environmentally friendly, socially acceptable and ...sustainable manner. Wood and agricultural residues such as walnut shells as lignocellulosic biomass are one of the most affordable and important renewable resources in the world, which can partially replace fossil resources. The overall objective of the research is to provide background information that supports new applications of walnut shells in a biorefinery context and to increase the economic value of these non-wood forest products. This paper presents the properties characterization of liquefied biomass according to their chemical composition. All results were compared to liquefied wood. In this study, the liquefaction properties of five different walnut shell particle sizes were determined using glycerol as the liquefaction reagent under defined reaction conditions. The liquefied biomass was characterized for properties such as percentage residue, degree of liquefaction, and hydroxyl OH numbers. The chemical composition of the same biomass was investigated for its influence on the liquefaction properties. Accordingly, the main objective of this study was to determine the liquefaction properties of different particle sizes as a function of their chemical composition, also in comparison with the chemical composition of wood. The study revealed that walnut shell biomass can be effectively liquefied into glycerol using H2SO4 as the catalyst, with liquefaction efficiency ranging from 89.21 to 90.98%.
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.
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.
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.
Model „brze mode" u modnoj industriji podrazumijeva proizvodnju trendovskih odjevnih predmeta koji imaju kratko vrijeme skladištenja i oglašavanja te su dostupni kupcima po povoljnim cijenama. ...Međutim, takav način proizvodnje potencijalno povećava količinu tekstilnog otpada. U ovom radu istražujemo koncept „brze mode" i njen utjecaj na klimatske promjene usporedbom između Portugala i Hrvatske. Istraživanje je istodobno opisno i analitičko. Primjeri dolaze iz presjeka populacija ovih dviju zemalja, nakon čega se retrospektivno analizira povijest predmeta istraživanja kroz izloženost ovom fenomenu i posljedice te izloženosti tijekom određenog vremenskog razdoblja. Podatke smo prikupili pomoću upitnika te analizom izvještaja o otpadu i podataka iz EuroStata. Rezultate smo analizirali pomoću programa IBM SPSS koristeći deskriptivnu statistiku i hi-kvadrat test. Rezultati su pokazali da se u Portugalu kupuju veće količine odjevnih predmeta u odnosu na Hrvatsku te da Portugal proizvodi više tekstilnog otpada pa je time veći i njegov učinak na okoliš. „Brza moda" je jedan od glavnih razloga za povećanje količine tekstilnog otpada. Upozoravamo na važnost poticanja kružne ekonomije, stimuliranja reciklaže tekstilnih materijala, povećanjem sakupljanja tekstila i ulaganja u reciklažne tehnologije. Ključno je stvaranje novog modela zatvorenog ekonomskog sustava za tekstilni sektor u kojem bi se odjeća i materijali ponovno koristili te ne bi završavali kao otpad.
There is a large potential for the production of energy crops on agricultural land. Global demand for food is expected to double within the coming 50 years, and demand for transportation fuels is ...expected to increase even more rapidly. There is a great need for renewable energy supplies for biofuel production that do not cause significant environmental harm and do not compete with food supply. In addition, biofuel by-products can be utilized as livestock feed with a substantial revenue source and significantly increases the profitability of the production process. Food-based biofuels can meet but a small portion of energy needs despite recent advances in crop yields and increased biofuel production efficiency. Therefore, biofuels that are non food-based are likely to be of far greater importance over the longer term. Reasonable values on the external effects are in most cases not enough to make agriculture-based biomass energy competitive so that considerable government subsidies are needed. Biofuels such as cellulosic ethanol that can be produced on agriculturally marginal lands with minimum fertilizer, pesticide, and fossil energy inputs, or produced with agricultural residues have potential to provide fuel supplies with greater environmental benefits that either petroleum or current food-based biofuels.
Biootpad se prema direktivama EU i zakonskim propisima Republike Hrvatske definira kao biološki razgradiv otpad iz vrtova i parkova, hrana i kuhinjski otpad iz kućanstava, restorana, ugostiteljskih i ...maloprodajnih objekata uključujući i slični otpad iz proizvodnje prehrambenih proizvoda. Iako se pojam biootpada miješa s pojmom biorazgradivog otpada, oni se bitno razlikuju. Naime, biorazgradivi otpad obuhvaća šire područje te uključuje i razne druge vrste biološki razgradivoga otpada kao što je otpad iz šumarstva, otpadna gnojiva, papir, karton, tekstil i sl. Zakon o održivom gospodarenju otpadom (NN 94/13) propisuje ograničenja u vezi odlaganja biorazgradivoga komunalnoga otpada na odlagališta, pa tako i otpada od hrane, a Pravilnikom o načinima i uvjetima odlaganja otpada, kategorijama i uvjetima rada za odlagališta otpada (NN 117/07, 111/11, 17/13) zabranjen je prihvat komunalnoga otpada na odlagalište ukoliko mu masa biorazgradive komponente premašuje 35% od ukupne mase. Definirane su i obveze odvojenoga sakupljanja biootpada s ciljem njegovog kompostiranja, anaerobne digestije ili energetske oporabe uvođenjem Pravilnika o nusproizovdima i ukidanju statusa otpada (NN 117/14) kojim su otvorene mogućnosti u pogledu gospodarenja ovom posebnom kategorijom otpada sukladno najmodernijim tehnološkim i najnovijim zakonskim tekovinama EU. Smanjenje nastanka otpada od hrane zauzima značajno mjesto i u programima europskih institucija. Prema dokumentu Europske komisije The Roadmap to a Resource Efficient Europe do 2020. godine odlaganje otpada od hrane na razini EU trebalo bi biti smanjeno za polovicu. Rad donosi analizu pripremljenosti i rezultata koje je Republika Hrvatska ostvarila ili mora ostvariti u narednom periodu te pregled mogućnosti obrade otpada od hrane.
The collapse of the banking system, financial crisis and the fall of free economy only deepened the problems of energy and ecology crisis. However, since crises create also new opportunities, the ...process of recovery has also given rise to green economybased on green technologies. World of labor, human needs, natural resources and their interrelations are basic for green economy and echnologies. It is the question of quality and not quantity. It is the recovery of individuals, communities and ecosystems. Green economy and green technologies are not just a question of
environmental protection and energy security. They create new horizons making the economy like a sailing boat in the wind of eco-system, creating the harmony of nature and human needs. It is the answer to overall crises that went into full swing in 2009 and have lasted ever since. In this paper will be described system of green technologies and green economy in Croatia case study.
PDF
