Browse

In the last decade, many researchers have asked themselves whether it is possible to have a different economic model from the so-called linear one, i.e. to move from the linear to the circular economy. The linear economy is based on the concept that the goods we use must follow a life cycle consisting of three phases. The first phase consists of the extraction of raw materials (or production of agricultural products). The second phase is the transformation of the raw material into semi-finished products. The final...

The area of interest is the synthesis and study of properties of new types of hydrogels made from pelt waste, in order to recover waste from tanneries. The research paper shows that exploratory research as a starting point to obtain new polymeric complex products -multicomponent - called hydrogels, by processing organic waste with applications in agriculture. Hydrogels that are based on biopolymers, compared with hydrogels based on synthetic polymers, have the advantage of biodegradability and a low level of toxic...

Economic analysis was performed for a new process that will be adapted to an existing coal-fired power plant process in order to recycle bottom ash with the objective of obtaining synthetic graphite. Synthetic graphite is a valuable raw material with many industrial applications. It can replace successfully natural graphite, saving capital and environmental costs associated to graphite extraction. Bottom ash resulting from combustion of low quality lignite at a Romanian coal-fired power plant contains significant ...

The waste management is a key factor for sustainable regional and local development. It affects directly to environment ? soil, water, air and etc., which are one of pillars of quality of life and living conditions. The article presents an approach for more easy understanding of the set of statistical data that monitored environment and in particular waste management. The waste management has been analyzed at national, regional and local levels. A share of treated municipal waste of total municipal waste generated...

In this study, three different waste biomass (soy waste biomass, mustard waste biomass and rapeseed waste biomass) resulted after oil extraction, were used as biosorbents for the removal of some heavy metal ions (such as Pb(II), Cd(II) and Zn(II)) from aqueous media. The biosorptive performances of each waste biomass were evaluated as a function of metal ions concentration in aqueous solution and contact time, and the obtained experimental results were modeled using Langmuir isotherm models and pseudo-second order...

Environmental pollution, which has extended its threat on the entire planet, reached the limit where attacks unleashed the man and his living space. Pollutants released by the global textile industry are continuously doing unimaginable harm to the environment. All actors along the supply chain have a role to play in reducing the environmental footprint of textile products. Passing over the capacity limits of nature defence, regenerative and balancing, all thenew pollutants are rapidly spreading through the air, wa...

The positive effect of mineral additions in cementitious materials (concrete, mortars, composite materials), proven by several studies along time, encouraged a complex research at NIRD ?URBAN-INCERC? Cluj-Napoca Branch regarding the potential valorisation of mineral wastes or by-products, generated by Romanian local industry, in new innovative cementitious materials for the construction industry. The central focus of the research was targeted towards fly ash and its potential use in reliable, high performance ceme...

In order to reduce the amount of waste in the production process, the efficient use of raw materials and energy, the concept of a circular economy is increasingly being introduced. Its main goal is the rational use of resources and raw materials, and the reduction of waste in the production process. One of the reasons for introducing this concept is to limit the negative impact of economic development on the environment. The implementation of this idea is not easy. Especially nowadays when technology is dynamicall...

Chicken meat is easy to produce, and as a result, it is a cheap and massively used source of animal protein in food. However, poultry farms produce more than 200 thousand tons of chicken manure per year, which must be treated. In the large scale farms biological treatment requires huge facilities and investments, therefore other methods are required. Among them, high-temperature drying and pyrolysis. The goal of this work was to compare the products of chicken manure treatment by means of two thermal methods - hig...

Sulfide ore processing is characterized by significant losses of non-ferrous and precious metals into various wastes including flotation tailings, which is presently considered as promising source of different metals along with low grade ores. Old flotation tailings, which have been accumulated in significant quantities during the exploration of some mineral deposits, usually contain a wide range of minerals, including sulfides (pyrite, chalcopyrite, sphalerite), sulfates, hydroxides, hydroxysulfates, etc. Thus, s...

The article describes an information-analytical system for assessing the impact of solid waste landfills on the environmental. The proposed system can be an informational basis for creating a national register of municipal solid waste, both authorized, acting in accordance with the requirements of current legislation, and unauthorized dumps. This basis will provide a scientific and economic justification for making decisions on the prospects for the management of municipal solid waste at the regional and local lev...

The use of recycled polyethylene terephthalate (PETr) in new value-added products is problematic because, during reprocessing in the melt, it undergoes a number of chemical, mechanical, thermal and oxidative degradations, which leads to decreased intrinsic viscosity / molecular mass and implicitly to poor mechanical and thermal properties. In the literature, numerous approaches have focused on obtaining polymer blends using PETr in combination with other thermoplastic polymers. Unfortunately, such mixtures are inc...

In the present work, films based on a potato starch/gelatin composition were prepared with a different ratio of components from 100/0 to 0/100 vol.%/vol.% with increment of 10 vol.% and addition of glycerol as plasticizer. The films were obtained with different drying regimes of the film-forming solutions at 25, 35, 45 and 50 °C for 24 h. For the obtained films the influence of their composition and the drying regime of the film-forming solution on the mechanical properties at puncturing, wettability and water sor...

Today, waste of electrical and electronic equipment is a big problem because it contains heavy metals such as copper, cadmium or nickel that cause neurological diseases. In addition, such waste also contains precious metals such as gold and silver, which makes this material really attractive for recovery. One of the fastest-generated groups of electrical and electronic waste is mobile phones. In 2008, the global sale of smartphones reached the level of 140 million units, while in 2015 it is rapidly growing to the ...

The ability of acidophilic microorganisms to oxidize sulfide minerals is increasingly used in biohydrometallurgical technologies to produce non-ferrous and precious metals from sulfide ores. Strains of Acidithiobacillus ferrooxidans and Sulfobacillus thermotolerans often dominate heap bioleaching processes. Due to their high ability to catalyze redox processes, it has been suggested that they can be used in the technology of microbial fuel cells (MFCs). MFC allows using organic and inorganic waste as a substrate f...

Several research projects of the Department of transportation engineering dealt with the issue of recycling and reuse of various materials into the pavement structure. By recycling and reuse of road construction materials, material and natural resources savings, environmental protection and energy savings were followed. The mixture with reclaimed material, most often reclaimed asphalt pavement (RAP), is of sufficient quality for the new road construction layer and can also affect the resistance to permanent deform...

After the end of use, they become e-waste and are recycled or put on the landfills. Recycling rate of e-waste in Slovakia was in 2017 according to Eurostat only 36.7 %. Recent studies show that yields from e-waste (mainly computers, mobile phones) are much higher than in metal ores and thus can be considered as valuable secondary sources of precious and base metals. In presented paper five different parts of computer e-waste were investigated for possible gold recovery, namely CPUs, CPU sockets, BGA chips, pins fr...

Metallurgical production generates ferrous waste at every stage of the process. Solid wastes that arise in metallurgical plants include, for example, blast furnace slag, sludge, dust, scale and others. The composition of these materials varies depending on the source of production. The use there fine-grained iron-bearing wastes is possible within a metallurgical cycle. Attention was paid to the possibility of scaling and subsequent use for the blast furnaces. The scales contain mainly FeO, so energy savings occur ...

In this study we examined such a high-keratin-content slaughterhouse by-product as pig bristles and poultry feathers. Our first and most important aim in this research to make a decision about the using direction of a final products. Only after our decision we can determine the most optimal treating and processing method for these slaughterhouse by-products. In our model experiment we can produce different products for example raw materials for cosmetics and petfood products. But the requirements of two main using...

Electronic waste is becoming a serious environmental and economical concern worldwide. The annual growth rate of about 4-5 % in 2016 is one of the fastest growing waste stream in municipal wastes and only about 20% of e-waste is recycled. The rapid growth in the use of electronic equipment caused by various socio-economic reasons has contributed significantly to the generation of large quantity of e-waste. After the use-phase, the electronic devices become electronic waste (e-waste); consequently, it is important ...

Synthetic cast iron was introduced into production 60 years ago, just after the development and production of medium and low-frequency high-capacity of induction furnaces (1 to 20 tonnes). This allowed the production of a wide range of cast iron, especially alloyed. Another significant effect was the increase in the portion of steel scrap up to 100% and, in particular, the reduction of the consumption of deficient and costly pig iron. Its price is up to twice as high as steel scrap. In the long time, the negative ...

Selective non-catalytic reduction of nitrogen (SNCR) oxides is a conventional technology applied extensively to conventional fuel combustion equipment in order to mitigate the emission of such oxides. The results of the process ? NOx concentration in the exhaust gas evacuated and the influence of the SNCR process on the overall combustion process depend on several factors and must be examined in each particular case. The paper presents a comparison between the situation before and after application of the SNCR pro...

We are the generations that are most acutely confronted with the reduction of natural resources and the negative effects of the impact of human activities on the environment, and this forces us to change both, our thinking and the way we relate to the environment and to the economic and social activities. The complexity of the 21st century human society and economy is also the most important source of vulnerability. As a result of aggressive consumption of resources, we must abandon existing linear economic models...

The possibility of using invertebrate animals as bioindicators of soil conditions has been shown, because microarthropods react strongly to environmental changes. The isotopic composition of heavy metals and their anthropogenic origin are analyzed. It was established that the highest content of heavy metals is in the soil in roadside green zones and the lowest-at a distance from sources of pollution. The assessment of soil invertebrate species with the influence of various levels of soil pollution has completed. T...

Technical lignins are by-products formed in the amount of about 70 million tons annually during the chemical and biochemical processing of plant biomass in the world. Most technical lignins are burned for energy. No more than 2% of technical lignins are supplied to the market mainly in the form of lignosulfonates due to their good solubility and surface activity. Modification of lignosulfonates can improve their properties and expand the field of practical use. In this study, we carried out a modification of sodiu...

This paper proposed an optimized method used for determination of minor elements (Cu, Zn, Mn) from Romanian biomass ash from three different biomass ash using ICP-MS technique. The purpose of the study was to find a suitable method of analysis for the complex matrix of biomass ash by comparing two samples preparation methods: at 5500C and 8200C. For this study the content of metals from three different samples from forestry and related industries (P1), forestry and exploitation (P2) and agriculture (P3) was analyz...

The paper is part of the analysis of the current issues on the challenges that should lead to a sustainable future based on the optimization of production processes and the reduction of waste, with a first contribution on a leading agricultural sector in Italy. In agriculture, there are very different experiences and practices, each of which has the potential to develop indicators to monitor report and communicate trends and progress towards the implementation of the circular economy. In this context, the document...

One of the most important alternatives in sewage sludge ash management is the recovery of essential elements such as phosphorus. Phosphorus is an important element for plants, food supply, human health and industry. Phosphorus is a non-regenerative resource and therefore it is important to find alternative sources to recover phosphorus. Phosphorus recovery as struvite (NH4MgPO4.6H2O) from sewage sludge ash has attracted special attention in the last decade due to the potential to be used as an ecologic fertilizer....

The relevance of the results. The experience of the EU countries shows that the process of involving regions in innovative development can be successfully carried out on the basis of "smart specialization" of the regions. A number of specialists consider "smart specialization" as a basis for the formation of both innovation and socio-economic policy. "Smart specialization" of regions allows to achieve 3 main goals: to choose priorities of interregional interaction; to involve in this process various organizations ...

Concrete slurry waste (CSW) from the production of prestressed poles production in original and Fe-modified form (CSWFe) was studied as potential adsorbent of environmentally risk cations (Cd2+, Pb2+) and oxyanions (AsO43- and CrO42-) from contaminated waters. Structural, surface and chemical properties of adsorbents were characterized by Powder X-ray diffraction (XRD), X-ray fluorescence (XRF), Specific surface area (SBET) and Scanning electron microscopy (SEM). Adsorption experiments ran in a batch manner at lab...

Production of castings plays an important part in the global and in the national economy. The main recipient of the foundry production is the automotive industry, but castings find application also in other branches of industry, in civil engineering, in farming, in medicine, and can as well serve art production. In 2016, worldwide casting production reached 104.1 million metric tons, a shade over the 103.7 million metric tons produced in 2015. The remaining 2015 top 10 casting nations by tonnage are Japan at 5.4 m...

The European Union ?circular economy? aims to maintain the value of products, materials and resources for as long as possible, minimizing the generation of waste by recycling and reusing them [1]. The leather industry generates large amounts of waste, more than 55% of raw material (hides and skin), and over 99% are stored at the landfill [2, 3]. Part of these waste generated are untreated solid waste (hide and skin), meaning around 500-600 kg per ton of raw hides [4, 5]. A way to valorize the untreated hide and sk...

The article discusses modern approaches and assessments of "resource regions" and "resource dependence". For the analysis of resource dependence, the data of Rosstat and customs statistics for 2005-2016 were used. The lower border (2005) is determined by the end of the period of economic recovery after the deep recession of the 90s. Moreover, 2005 is the first year when data on the share of extractive industries in the gross regional product of the region began to be calculated. 2016 is the last year for which dat...

In this article, I will focus on the possibilities of recycling aluminium chips and chips from aluminium alloys. Recycling can be divided into conventional recycling, by remelting the material, or the unconventional method of recycling it in its solid state, in which the chips can be transformed directly into dense bulk materials. The advantages of this method lie in lower energy consumption, reduced metal losses, almost no emissions of harmful gases and minimum waste. In the introduction I will introduce the meth...

jewellery, construction materials, in the mechanical systems and energy generation). The popularity of the use of copper alloys caused an increase in the application of these materials and the increase in the demand for recovery of previously used metals that are components of these alloys. The sources of materials from which the above-mentioned metals are recovered can be: brass scrap, elements from electric furnaces, electronics, car scrap and alkaline batteries. Thus, in recent years, the demand for the recover...

Tin is widely used in the electro-technical industry, mainly for the production of the solders and tin-sheets. Resources for the production of primary tin are currently limited. Therefore, the importance of secondary methods - the recovery of tin from waste - is growing. However, the recycling of tin is associated with many technological, economic and environmental problems. It is usually energy-intensive. One of the compromising methods is "dilution" - secondary tin is mixed with high purity primary tin. However,...

Ash and slag waste constitutes a significant part of the waste of heating and power plant (CHP) complexes operating on solid energetic fuel. For the most part, this by-product does not find further application, accumulating in ash dumps. Meanwhile, taking into account the global trend towards the involvement of ash and slag waste in industrial processing, it is necessary to predict their recycling in Russia. However, for recommend recycling type of ash and slag it is necessary to know their structural and material...

Reverse vending machines (RVM) are a key part of used plastic containers utilization system in Europe and the United States. Waste recognition and sorting in RVM machines can be performed by any of the following procedures: by determining the container material (e.g. using the IR-spectrometer), by recognition of the container type by its shape, or by the barcode identification.[1] These three basic control-procedures make any attempt of the fraud completely impossible. But at the same time, it makes the RVM too ex...

Circular economy has become a world trend, and the only way of economic sustainable development. Waste utilization in concrete technology have much to offer in terms of helping to achieve circular economy goals. Recently various types of waste have been widely recycled as a substitute of fine aggregates in concrete technology. The use of waste as a replacement of natural aggregate is the best sustainable method in order to find alternative ways for conserving the environment. Concrete is the most widely used build...

The global economy needs significant changes that will reduce the high consumption of natural resources and the amount of waste generated. The idea of solving the circular economy proposes a path to solve such problems. Thematically, it covers social, political, economic and production issues. However, it should be noted that Circular Economy is not a ready recipe for solving the problems of depleting raw materials and the deteriorating condition of the environment. The basic premise of Circular Economy is a simpl...