Transformation Of Solid Waste Research Articles

The simultaneous removal of methylene blue (MB) and Ca2+ by recyclable adsorbents based the scales derived from coal gasification system.

The transformation of solid wastes from industrial production into effective adsorbents could significantly contribute to wastewater treatment. In this study, after acidizing and burning soft scale (SS) from coal gasification system, two magnetic adsorbents (mag-ASS and mag-BASS) were prepared via the combination of magnetite with ultrasonic, respectively. The treatment effects of mag-ASS and mag-BASS were then investigated for simulated wastewater containing macromolecular organic matter [i.e., methylene blue (MB)] and Ca2+. The results indicated that the pseudosecondorder kinetic, Elovich, Freundlich,Langmuir and Temkin model could well describe the adsorption behavior of MB and Ca2+ onto mag-ASS and mag-BASS. The maximum adsorption capacities of mag-ASS for MB and mag-BASS for Ca2+ were 600.53mg/g and 102.54mg/g, respectively. Surprisingly, the adsorption abilities of mag-ASS for MB and mag-BASS for Ca2+ showsignificantly higher than the others. The adsorption mechanisms of MB mainly included electrostatic interaction, π-π conjugate interaction and cation exchange, while those of Ca2+ were mainly electrostatic interaction and cation exchange. The diffusion of MB and Ca2+ onto the magnetic adsorbents might be controlled by the combined effects of intraparticle and liquid film diffusion. There was no significant reduction in adsorption capacity after 8 cycles of adsorptionand desorption, indicating that SS-based magnetic adsorbents had good recyclability and stability. Moreover, the removal efficiency of mag-BASS for total hardness and total organic carbon in real coal gasification gray water (CGGW) was 82.60 and 64.10%, respectively. The treatment of CGGW and theresource of wastes would significantly promote the reasonable disposal of coal gasification scales.

Synthesis of multifunctional porous carbon-silicon composites from coal gasification fine slag: Adsorption of methylene blue and microwave-induced biomass catalytic pyrolysis

Coal gasification fine slag (CGFS) is an important byproduct in the coal gasification process with a huge annual output in China and its efficient and green conversion is one of the key issues in the development of coal chemical technology. In this study, using CGFS as the raw material, a facile method was designed for the preparation of multifunctional porous carbon-silicon composites through one-step alkali fusion based on its carbon, silicon and metal elements composition. It was found that the reaction proceeded more adequately using KOH as the activator and the obtained material (T-K1) was mainly composed of micropores and mesopores. A great number of prismatic nepheline crystals were formed and embedded in the honeycomb porous carbon. The specific surface area of T-K1 reached 424.33 m2/g with a variety of active functional groups on the surface. The porous composite exhibited great potential as a multifunctional adsorbent and catalyst. Using T-K1 as an adsorbent, its equilibrium adsorption capacity on methylene blue (MB) reached 208.44 mg/g at 298 K. The adsorption process was consistent with the situation described by the pseudo-second-order kinetic and the Langmuir model, and the adsorption mechanism mainly originated from cation exchange, van der Waals forces, π-π interaction, hydrogen bond and electrostatic attraction. In addition, T-K1 can act as both a catalyst and a microwave absorber in the microwave pyrolysis of biomass. Taking pine sawdust as an example, H2 and CO in the gas product were enriched with high yields of 126.4 and 178.9 ml/g at 550 °C respectively, and the relative content of the phenolic in bio-oil increased to 53.6%. It is believed that this process can provide a useful alternative for the high-value-added transformation of solid waste containing carbon and silicon.

Heavy metal migration regimes in the production of syngas from solid waste by thermal plasma treatment

In recent years, thermal plasma technology has been widely used in the harmless and resource-efficient treatment of solid waste (SW). This study investigates the migration behaviors of heavy metals during the thermal plasma treats SW to obtain the interphase structure change regimes of heavy metals. The transformation of SW under high-temperature environments was analyzed by Fluent simulation, and the composition of the crystalline phases and heavy metal content of the post-treatment slags were studied through a combination of XRD, SEM, and heavy metal leaching experiments. The results show that the thermal plasma provides a melting zone temperature of more than 4000 K, and the treated slag is mostly an amorphous solid composed of glassy Si-O mesh, which effectively encapsulates heavy metals and reduces their leaching rate. Additional analysis of the migration and transformation of heavy metals during thermal plasma treatment revealed that solid-phase heavy metals primarily took the form of sulphides and sulphates, while liquid- and gas-phase heavy metals were mostly oxides and chlorides. Simultaneously, Economic analysis results showed that the thermal plasma treats SW economically with an Energetic efficiency of up to 76.7%. The results of this study providing new insights into thermal plasma treatment SW research.

Application of biochar derived from used cigarette filters in direct carbon solid oxide fuel cell

As a typical waste, used cigarette filters (UCFs) are difficult to biodegrade and harmful to the environment. The direct carbon solid oxide fuel cell (DC-SOFC) is an energy conversion device that can utilize carbon directly, including biochar, as fuel. We report a superior DC-SOFC powered by Fe-loaded UCF biochar in this paper. The microstructure and composition are characterized, indicating that the UCF biochar is micron-sized and contains metal elements such as K and Ca that are beneficial to the performance of DC-SOFC. The peak power density of the cell fueled by pure UCF biochar is 308 mW cm−2 and increases to 341 mW cm−2 after loading Fe as the catalyst, which is comparable to that of the cell with Fe-loaded activated carbon (368 mW cm−2). It proves the feasibility of the UCF biochar as fuel for DC-SOFCs, providing a theoretical basis and technical demonstration for the disposal and transformation of solid waste.

Patent technometry by mind maps: a study on the recycling of waste electrical and electronic equipment

Objective: To demonstrate the possibility of relating bibliographical review and patent technometry in a study on the recycling of waste electrical and electronic equipment (WEEE). Method: Technometry in patents using a mind map generated from the classification of 466 patent registers. The prospecting of patents was carried out through the software Patent2Net accessing the database of the European Patent Office (EPO). Originality/Relevance: Research in patent databases as a source of information has been growing substantially with advances in information technology, but the identification of relevant records in a given context from the large volume of data available is still a challenge. In this work, we have analysed a method that has not yet been published, which deals with patent technometry with the use of mind maps. Results: The patent records found were related to the main problems mentioned in the literature on WEEE recycling, involving the following aspects: a) separation of high-value components from other elements. b) reduction of the environmental impact of battery recycling; c) transformation of solid waste into material useful or harmless to the environment; d) separation of metals from plastic waste; e) solutions for the adequate collection of residues from the domestic environment; and e) techniques to reduce the health impact of recycling professionals. Theoretical/methodological contributions: Presentation of the method of patent analysis by mind maps as a complementary resource to bibliographic research in studies aimed at technological innovation.

Transformation of Solid Waste into Nanoporous Carbon via Carbothermic Reduction.

Continuous population growth and rapid urbanization will outpace the global capacity of solid-waste disposal. Although pyrolysis, in the waste management sector, has been regarded as a savior to bring potential returns, it has struggled against high operation costs. Here, we found that simple pyrolysis of properly mixed wastes [e.g., organic wastes (C) + metal wastes in the form of metal oxides (MxOy)] can bring about the carbothermic reduction [C(s) + MxOy(s) → C′(s) + M(s) + CO(g)] caused by the thermodynamic reducibility of metal oxide. This process consequently produced not only nanoporous carbon powder usable for energy storage devices but also nanoporous carbon fully decorated with magnetic nanoparticles useful for magnetic applications. We believe that the carbothermic reduction process, historically used for metal refining, could be a promising alternative to resolve the long-pending issues of the conventional pyrolysis approach as well as to produce useful nanoporous carbon with ease. Our method could be a simple and effective way to transform ubiquitous solid waste into useful resources in the form of nanoporous carbon.

Manejo de recursos sólidos para la creación de ambientes óptimos de aprendizaje

At a global level there is a problem of environmental pollution, generated by human activities, largely due to the improper handling of solid waste, which is why educational institutions are expected to generate pedagogical strategies that encourage students to adopt environmental attitudes, to preserve its environment. The purpose of the study was to promote the management of solid resources for the creation of optimal learning environments. The methodology was oriented under the qualitative approach, using the type of action research, from a descriptive, exploratory design. For the collection of data, techniques such as; participant observation and field diary. A sample of twenty-four (24) students from elementary school to eleventh secondary school was chosen from the Macondo Departmental Educational Institution of the Jose Celestino Mutis Rural School for males. An integral management of solid waste was evidenced as part of the learning process of the institution, reaching conclusions with an importance in the transformation of solid waste that improve the school environment.

Potential and possibilities of vermicomposting in sustainable solid waste management: a review

Treatment of solid wastes using earthworms has been intensively investigated in recent years. Most of the agricultural, urban or industrial organic materials can be used for vermicomposting, ensuring that they do not contain toxic materials, which can harm the earthworms. The transformation of solid wastes into vermicompost is of double interest: a waste is converted into value-added product and it controls a pollutant that is a consequence of increasing population, urbanisation and intensive agriculture. This paper deals with the state of research on various aspects of vermicomposting process.