Accumulation Of Solid Waste Research Articles

Flyash and coffee silverskin binary blended geopolymer

Exploring alternative precursors other than flyash, slag, metakaolin and palm oil fuel ash for geopolymer synthesis has become very essential owing to the need for reduction in cost and accumulation of solid waste that could contribute to environmental pollution. The use of coffee silverskin (CSS) in binary blending with flyash (FA) in geopolymer synthesis is not yet fully understood, although its performance in ternary blending with silica fume for ordinary Portland cement (OPC) mortar has been established. Thus, binary blended CSS (0–30 %) with FA - such that CSS/(FA+CSS) varied from 0 to 0.3 - was activated by sodium hydroxide (8MNaOH) and sodium silicate (Na2SiO3), and then subsequently cured at 60 °C. Mechanical property, binder morphology, compound product phases and bond characteristics were studied through compressive strength test, scanning electron microscope (SEM/EDS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIRS), respectively. CSS (CSS/(FA+CSS) = 0.3) significantly contributed to strength loss due to microcracks, carbon content and fiber induced microstructural discontinuity, such that 7-,14-and 28-d strengths recorded were 5.2, 7.8 and 9.7 MPa, respectively. Maximum 28-day strength of 16.5 MPa was recorded in CSS/(FA+CSS) = 0.1. CSS caused the formation of monetite, and disappearance of muscovite and augite in flyash/coffee silverskin based (FACSS) geopolymer.

Japan’s experience in organizing and promoting separate accumulation of municipal solid waste (MSW)

The article considers the Japanese system of municipal solid waste management as well as work with the population in the field of environmental education. The roles and responsibilities of the parties in the management of municipal solid waste are analyzed. In Japan, unlike other countries, the state is deeply involved in the process. Sorting and disposal of waste occur at the municipal level due to the historical characteristics of the Japanese society. Extended producer responsibility requires their participation from product development to disposal, and consumers are required to cooperate with them and local authorities by properly disposing solid waste.The regulatory framework in the field of MSW management is built around the Basic Act on Establishing a Sound Material-Cycle Society and the Law for Promotion of Effective Utilization of Resources, which formulates the 3R strategy, aimed at Reducing, Reusing, and Recycling of waste. An analysis of recently adopted documents, the Plastic Resource Circulation Act of 2021 in particular, demonstrates that special emphasis is placed on 2R: waste reduction and reuse, which is successfully achieved thanks to the high level of environmental awareness of Japanese citizens and thoughtful and multifaceted educational work with the population.Over the past decade, Japan has seen a steady reduction of municipal solid waste. However, while remaining one of the world leaders in the field, it is currently faced with a number of difficulties, such as a low recycling rate and a significant volume of incinerated waste. It is concluded that significant progress in this area is impossible without clearer goal setting for the volume of solid waste processing that would meet modern world standards.

Mechanical and shrinkage properties of alkali-activated mortars with graphite tailings

To improve the problems of high CO2 emission generated by the preparation of silicate cement, large accumulation of solid waste, and depletion of natural sand resources, this paper investigates the effect of pozzolanic effect of graphite tailings (GT) on the mechanical properties, shrinkage properties and microstructure of alkali-activated mortar, and less research has been done on this related content. This paper partially replaced the natural sand with GT, and completely replaced the cement with fly ash and slag to prepare alkali-activated fly ash-slag (AAFS) mortar. The consequences of GT replacement rate on the mechanical and shrinkage characteristics of AAFS mortar were analyzed. In addition, X-ray diffraction (XRD), mercury-in-pressure (MIP), and nuclear magnetic resonance (29Si MAS NMR) were used to examine the hydration degree, pore structure, and hydration products of AAFS mortar. The results demonstrated when the Na2O content was 7 % and the activator modulus was 1.0, the test group's 28-day flexural and compressive strengths at a 20 % GT replacement rate were increased by 19.49 % and 14.45 %, respectively, compared to the test group without GT. The appropriate quantity of GT reduced the AAFS mortar's drying shrinkage and increased the AAFS mortar's self-shrinkage. According to the microstructure analysis, GT had a pozzolanic effect: moderate doping of GT promoted the hydration reaction of precursors, improved the amount of C-(A)-S-H gel product generated, and improved AAFS mortar's mechanical and shrinkage properties.

Investigation of the activator system for coal gangue and its optimal utilization in composite cementitious materials

The extensive accumulation of coal-derived solid wastes in China has become a significant environmental challenge. Utilizing these wastes as resources is considered an effective approach. This study investigated activation systems for coal gangue to determine the optimal dosage for incorporation into cementitious materials. The effects of types and dosages of admixtures on the mechanical properties were examined. The results showed that augmenting the coal gangue content within a certain range enhanced the compressive strength of the composite cementitious materials. However, exceeding 20 wt.% led to a decline in compressive strength. The addition of coal gangue led to an increase in porosity. Furthermore, the addition of 4% lime and 4% gypsum resulted in enhanced properties. The performance of the resultant optimal cementitious material surpasses that of P·O 32.5 cement, making it a viable replacement in construction sector and contributing to the realization of resource recycling and ecological civilization construction goals.

Down flow jet-loop reactor with NF-RO membrane system for the treatment of textile wastewater

Textile industries are significant consumers of fresh water, extensively using it for washing and dyeing processes. The effluent from these operations contains various chemicals, including complex synthetic dyes, NaCl and Na2SO4 necessitating efficient treatment before discharge into water bodies. Zero Liquid Discharge (ZLD) technology facilitates complete water recovery but leads to substantial solid waste accumulation, which poses challenges for reutilization. This study introduces an innovative approach using a Downflow Jet Loop Reactor combined with ozone and activated carbon to effectively remove color and Chemical Oxygen Demand (COD) from textile effluent. Furthermore, a combination of Nanofiltration (NF) and Reverse Osmosis (RO) membrane systems ensures comprehensive purification by effectively separating inorganic salts. Experimental results demonstrated a maximum color removal of 81.25 % from the textile effluent. The fabricated PSF/PVDF NF membrane exhibited exceptional capacity for rejecting divalent salts. Additionally, the RO reject, which is a concentrated solution of salts and contaminants, was successfully reused in a dye bath for cotton fabric dyeing. This approach highlights the practicality, sustainability, and resource conservation potential within the textile production cycle. It underscores the importance of a comprehensive water treatment strategy for achieving sustainable textile production.

Mineralized carbon sequestration evaluation of coal-based solid waste consolidated backfill: A novel data-driven approach

The coal mining industry and its byproduct utilization are confronted with challenges such as the accumulation of coal-based solid waste and the emission of CO2, which seriously jeopardize environmental protection. A lucrative way of mitigating these problems is CO2 mineralization storage technology of coal-based solid waste consolidated backfill. Its successful realization stringy depends on the CO2 mineralization sealing stock and requires accurate account of the carbon sequestration rate of cemented backfill. Therefore, this study proposes a novel hybrid intelligent model combining the adaptive enhanced whale optimization algorithm and the support vector regression (A-E-WOA-SVR) to forecast the carbon sequestration performance of cemented backfill. The respective data set of cemented backfill was obtained through laboratory tests under different values of seven factors influencing the carbon sequestration rate, including water–solid ratio, cement ratio, fly ash ratio, slag ratio, curing pressure, curing temperature, and curing time. The results exhibit that the adaptive enhanced whale optimization algorithm can effectively optimize the hyperparameters of the support vector regression. The A-E-WOA-SVR hybrid intelligent model proposed in this paper accurately predicted the carbon sequestration rate of cemented backfill. Coefficient of determination, mean absolute error, root mean square error, and other indices were used to evaluate the performance of the intelligent prediction model. The obtained values of these indices implied small errors. The mean impact value sensitivity analysis revealed that water–solid ratio, cement content, curing pressure, and curing time were the key sensitive factors controlling the carbon sequestration performance of cemented backfill, which should mainly considered in the control of cemented backfill mineralization carbon sequestration performance. The research results provide a theoretical reference which enhance the CO2 mineralization storage performance of coal-based solid waste consolidated backfill.

Efficient utilization of coral waste for internal curing material to prepare eco-friendly marine geopolymer concrete

To address shortages in construction materials for island engineering, tackle the accumulation of solid waste, and inhibit the shrinkage of geopolymers, coral waste was utilized as the internal curing material to prepare high-performance marine geopolymer concrete (MGC) with seawater, sea-sand, and normal limestone aggregate (LsA). The coral coarse aggregate (CorA) used in this investigation has a total porosity ranging from 50% to 58.3% with internal pore diameters spanning 50–400 μm. The water desorption of CorA followed a two-stage pattern within a relative humidity (RH) range of 75%–85%, becoming nonlinear above 90% RH, which released about 85% of its moisture within 200 h at 97% RH, demonstrating potential for internal curing. Adding a small amount of CorA to MGC increased slump and setting time by providing internal curing water. However, as CorA content exceeded 30%, the slump significantly decreased due to reduced mixing water and elevated activator concentration, while the initial setting time slightly decreased. Furthermore, the inclusion of saturated CorA in MGC significantly reduced autogenous shrinkage, with higher CorA contents (exceeding 30%) leading to slight expansion in the early stages and nearly eliminating shrinkage at contents above 40%. The greater drying shrinkage in geopolymer systems compared to ordinary Portland cement is due to capillary pressure compressing the product framework, converting larger gel pores into smaller ones. Additionally, the layered calcium aluminosilicate hydrate (C-A-S-H) gel exhibits more pronounced creep characteristics under low internal humidity conditions. The higher CorA content in MGC promoted the formation of hybrid C, N-A-S-H gel and hydrotalcite-like phases, and reduced carbonation issues. The interfacial transition zone (ITZ) between CorA and the geopolymer matrix formed a robust mechanical interlock, enhancing tensile strength and minimizing shrinkage-induced cracks. Based on overall performance and marine material utilization, an optimal substitution rate of CorA between 40% and 50% is recommended.

Preparation and property study of sawdust-modified cement mortar

Sawdust, a solid waste generated during stone processing, poses a serious threat to the environment with its untreated accumulation. This paper first analyzes the chemical composition and physical properties of sawdust, and discusses its mechanism of action in cement mortar. By systematically optimizing the blending ratio and modification method of sawdust, the sawdust-modified cement mortar with excellent performance was prepared. This study evaluates the key performance indicators of sawdust-modified cement mortar, such as compressive strength, flexural strength, and durability, through a series of experiments. The experimental results indicate that the incorporation of an appropriate amount of sawdust significantly enhances the mechanical properties of cement mortar, while also improving its durability, particularly in terms of freeze-thaw resistance. Microstructural analysis reveals the mechanism by which sawdust improves the pore structure of cement mortar; the active components in the sawdust react with the hydration products of cement, resulting in the formation of crystalline structures with higher strength.Therefore, the use of sawdust as a modifier in cement mortar can improve its mechanical properties and durability, while simultaneously reducing the accumulation of solid waste and promoting the sustainable development of building materials.

Assessing performance, economic costs and environmental benefits of high-performance ecological geopolymer concrete incorporating excavated rock and soil from tunnelling, fly ash and slag as reclaimed raw materials

Excavated rock and soil from tunnelling (ERST), fly ash (FA), and slag are one of the largest sources of solid waste and play an important role in reducing dependence on natural resources and solving the problem of solid waste accumulation. This study verifies the feasibility of high-performance ecological geopolymer concrete (HPEGC) incorporating ERST, FA and slag for engineering applications. The effects of different binding material to machine-made sand ratio (BMMSR) and SN/FS (the total mass of sodium silicate and NaOH solids to the total mass of the powdered raw material) on the slump, compressive strength, tensile strength, drying shrinkage, salt corrosion resistance of concrete and the microstructural deterioration process before and after salt corrosion were analysed by indoor tests and microscopic tests. The results showed that the hydration products generated at SN/FS of 10, 12, and 15 % could effectively fill the pores of HPEGC and improve the pore structure and interfacial properties of HPEGC by microminiaturisation of the pore size. HPEGC formed a dense three-dimensional reticulated polysilica-aluminate-like structure due to the coexistence of C-S-H gel, C-A-S-H gel, N-A-S-H amorphous gel, and Na2Al2Si3O10. HPEGC with SN/FS of 12 % and BMMSR of 0.36 showed 29.5 % and 18.9 % improvement in compressive and tensile strengths, better resistance to sulfate attack, and 4.5 % and 45 % reduction in economic cost and GHG emission, respectively, compared with ordinary Portland cement concrete (OPCC). The results of the study proved that the engineering application of HPEGC incorporating ERST, FA and slag as raw materials is promising, providing new solutions for global underground excavation materials and industrial solid waste, and effectively promoting the sustainable development of the construction industry.

Evaluation of solid medical waste management system in Undata Regional General Hospital, Palu city, Central Sulawesi Province, Indonesia

Waste is an environmental problem that is still not fully resolved properly even though the resulting impact has a major effect on environmental pollution, especially solid medical waste. The purpose of this study was to assess the characteristics of solid medical waste at Undata Hospital based on its sources and types, calculate the average weight of solid medical waste generated per day, and evaluate the solid medical waste management system with sorting, packaging, collection and transportation modes in accordance with the criteria of Permen of Environment and Forestry Number 56 of 2015 and Permenkes Number 2 of 2023. This research uses a qualitative approach with a descriptive research type. This research was conducted in August-September 2023. The sampling technique in this study used Purposive Sampling, with 18 informants selected from each unit/room/installation at Undata Hospital, Palu City. Based on the results of the study, it was found that every day Undata Palu Hospital produces domestic waste as much as ± 270 kg / day. The results of the evaluation of the solid medical waste management system at Undata Palu Hospital show that basically it is quite effective but not optimal, because the storage process shows non-compliance with the guidelines for medical waste management by the Ministry of Health Number 2 of 2023, namely storage in TPS which should not be more than 2x24 hours, but in fact the accumulation of solid medical waste is stored for 1 month in the LB3 TPS due to delays in transportation by third parties. This causes a large amount of solid waste in the TPS so that the TPS becomes full and dangerous because the waste undergoes a process of decomposition and decay, which is harmful to the environment and human health. Undata Hospital needs to maximize the procurement of internal medical waste processing equipment (incineration equipment) which needs to be supported by the Environmental Agency and the relevant Health Office to prevent environmental pollution from medical activities.

Durability of geopolymer cementitious materials synergistically stimulated by Ca2+ and Na+

Fewer studies related to the durability of multi-source solid waste geopolymer cementitious materials and the massive accumulation of industrial solid waste are urgent problems to be solved in practice in Inner Mongolia, China. In this paper, blast furnace slag (BFS), fly ash (FA), and calcium carbide slag (CCS) are used as the main raw materials to prepare geopolymer cementitious materials (BFCG) with Calcium Carbide Slag as the Ca-source alkali activator and NaOH as the Na-source alkali activator, considering their durability properties. By assessing the indicators of mechanical performance, engineering performance, and the synergistic mechanism of Ca2+ and Na+ in multi-source solid waste geopolymer, four sets of BFCG ratio optimization schemes are selected. XRD, FT-TR, SEM-EDS, and other testing methods are used to analyze its freeze–thaw resistance and acid–alkali-salt corrosion resistance. The following conclusions are drawn: the BFCG prepared under the synergistic excitation of Ca2+ and Na+ has better resistance to freezing and thawing, as well as acid-alkali-salt corrosion, both of which are in accordance with the standard specifications for road construction in China. After the freeze–thaw cycles, BFCG still has more three-dimensional network-like silica-aluminate structures, a compact micromorphology, and small pores. Its strength loss rate is 0.56 %–15.56 %, the mass loss rate is 0.19 %–1.26 %, and the relative dynamic modulus is 79.56 %–100.25 %. In a NaOH environment, the crystal type of BFCG did not change significantly, and the resistivity coefficients are 115.78 %–143.54 %. In a Na2SO4 environment, the decalcification or dealumination of C-A-S-H gel leads to the formation of a gel rich in silicon, magnesium, and aluminum phases, with a corrosion resistance coefficient of 101.8 %–119.96 %. In a HCl environment, HCl erosion inhibits the growth of hydration product crystals, with corrosion resistance coefficients ranging from 73.83 % to 97.24 %. BFCG-D has the best resistance to freezing and thawing as well as acid and alkali corrosion. BFCG-D has the best resistance to freezing and thawing as well as acid and alkali corrosion. These studies show that BFCG offers a promising solution for improving the durability of road base materials and reducing industrial solid waste.

Prediction of the Dangerous Range of Dumps Based on a Dynamic Process

A dump is a loose accumulation of solid waste from mining operations that easily leads to disasters such as landslides and debris flows. Taking a dump in the Panzhihua region of China as an example, based on the MPM and SPH meshless methods, the dynamic calculation of the instability process of the spoil slope was carried out according to the realistic three-dimensional calculation model of the generated terrain. Firstly, the strain and displacement of the dump under normal conditions and heavy rainfall conditions were simulated by the MPM material point method. The maximum spatial displacement of the dump under heavy rainfall conditions reached up to 386 m. Then, the motion and morphology of the accumulation of the dump under ordinary working conditions and heavy rainfall conditions were analyzed using the smooth particle hydrodynamics (SPH) method. Under heavy rainfall conditions, the maximum horizontal displacement of the dump was approximately 394 m. The research results are conducive to the risk assessment of the spoil slope and provide theoretical support for the calculation of the range of potential threats from the dump.

Stepwise extraction of lithium and potassium and recovery of fluoride from aluminum electrolyte wastes through calcification roasting-two-stage leaching.

Aluminum electrolyte is a necessity for aluminum reduction cells; however, its stock is rising every year due to several factors, resulting in the accumulation of solid waste. Currently, it has become a favorable material for the resources of lithium, potassium, and fluoride. In this study, the calcification roasting-two-stage leaching process was introduced to extract lithium and potassium separately from aluminum electrolyte wastes, and the fluoride in the form of CaF2 was recycled. The separation behaviors of lithium and potassium under different conditions were investigated systematically. XRD and SEM-EDS were used to elucidate the phase evolution of the whole process. During calcification roasting-water leaching, the extraction efficiency of potassium was 98.7% under the most suitable roasting parameters, at which the lithium extraction efficiency was 6.6%. The mechanism analysis indicates that CaO combines with fluoride to form CaF2, while Li-containing and K-containing fluorides were transformed into water-insoluble LiAlO2 phase and water-soluble KAlO2 phase, respectively, thereby achieving the separation of two elements by water leaching. In the second acid-leaching stage, the extraction efficiency of lithium was 98.8% from water-leached residue under the most suitable leaching conditions, and CaF2 was obtained with a purity of 98.1%. The present process can provide an environmentally friendly and promising method to recycle aluminum electrolyte wastes and achieve resource utilization.

Evaluating coastal lagoon sustainability through the driver-pressure-state-impact-response approach: a study of Khenifiss Lagoon, southern Morocco

Coastal lagoons are valuable ecosystems, providing socioeconomic benefits and supporting human populations and biodiversity. However, these systems face several challenges, making them vulnerable to both natural and human factors. In this study, we apply the Driver-Pressure-State-Impact-Response (DPSIR) Approach to conduct a comprehensive socioeconomic and environmental assessment of the Khenifiss Lagoon to promote sustainable development and support decision-makers. Located on the southern Atlantic coast of Morocco, the lagoon was designated a natural reserve in 1962, a biological reserve in 1983, and a protected wetland under the Ramsar Convention since 1980. This study represents the initial endeavor to conduct a comprehensive global and multidisciplinary environmental assessment of the lagoon by using a wide range of data sources, including relevant publications and reports, satellite images and remote sensing data, field observations, and interviews, all analyzed under the DPSIR framework. Our findings show that both natural and human factors have an impact on the ecosystem. Natural Factors associated with the geomorphological features of the region likely contribute to the silting of the lagoon, possibly intensified by a large shipwreck stuck at its inlet. Meanwhile, human factors encompass population growth (at a rate of 2% per year), tourism, shellfish farming, fishing, shellfish harvesting, and salt extraction. Our results reveal significant changes in the lagoon’s condition in recent years, including a reduction in water body extent, a probable decrease in depth, and an increase in the accumulation of solid waste, plastics, and wastewater in three sectors spanning a total surface area of 464 ha (equivalent to 7% of the lagoon), a substantial expansion of the salt mining area encompassing 368 ha, and a remarkable loss of biodiversity, manifested in declining fish stocks and seabird populations. This study showed that the lagoon is positioned as a potential site for economic growth and serves to alert stakeholders and the local population to the ecosystem’s environmental issues. Based on the findings of this study, we highly recommend regulating human activities within the lagoon, the removal of the wreck at the entrance, proper waste management, community awareness programs, and strict monitoring and enforcement of regulations to protect the environment.

Converting municipal solid waste incineration bottom ash into the value-added artificial lightweight aggregates through cold-bonded granulation technology

To effective recycle the Municipal solid waste incineration bottom ash (MSWIBA), this study adopts cold consolidation granulation technology to develop eco-friendly artificial lightweight aggregates (ALCBAs), and the materials are over 50 % dosage of MSWIBA, less 50 % fly ash (FA) or ground granulated blast furnace slag (GGBFS), and 10 % ordinary Portland cement (OPC). This study investigated the effects of different binder types and dosages on the properties of ALCBAs, including compressive strength, water absorption rate, bulk density, microstructures, pore development, heavy metal leaching behavior, and sustainability. The feasibility of ALCBAs to design green concrete was also explored. The results show that with higher content of MSWIBA and binders of FA, GGBFS and OPC, the ALCBAs with compressive strength greater than 2.5 MPa, bulk density of about 1000 kg/m3 and water absorption rate greater than 12 % was successfully developed. Increasing the content of FA/GGBFS is beneficial to improve the compressive strength and reduce the water absorption rate and the total porosity and lower the air bubbles percentage of ALCBAs. More importantly, both FA and GGBFS are mixed into ALCBAs, the compressive strength is at 2.5 MPa-3.0 MPa, the water absorption rate is significantly reduced, and the energy consumption, carbon footprint and cost are also significantly reduced. As the content of ALCBAs increases, although the compressive strength and splitting tensile strength are not as good as concrete with natural aggregates, the density of low-carbon concrete with ALCBAs gradually decreases, and the interface transition zone is gradually improved. Overall, ALCBAs can be beneficial to the conservation of natural resources (natural aggregates) and effectively solve the shortage of natural aggregates, and can be used to deal with the accumulation of solid waste in a green way, and it also can open up new channel for solid waste recycling.

An effective way to utilize solid waste resources: The application of modified fly ash in removing Cu2+ and Pb2+ in wastewater

The sustainable development of society requires the support of developed industrial production, which inevitably produces a series of industrial by-products, including heavy metal-containing wastewater and solid waste. Using solid waste to adsorb heavy metal ions in wastewater is a sustainable way. This not only reduces the environmental threat caused by solid waste accumulation, but also reduces the treatment cost of heavy metal ions in wastewater. In this study, fly ash was modified to prepare magnetic adsorbent (M-AT), which was used to adsorb Cu2+ and Pb2+ in wastewater. The results showed that M-AT has a good adsorption effect on Cu2+ and Pb2+ in wastewater. Its maximum adsorption capacity for Cu2+ and Pb2+ was 53.18 and 85.86 mg/g, respectively. Ion exchange and complexation reaction were major adsorption mechanisms of M-AT for Cu2+ and Pb2+, they played an important role in the adsorption process. M-AT maintained a good adsorption effect on Cu2+ and Pb2+ under different influence factors. This ensured that M-AT can be used in complex application environments. In addition, M-AT exhibited good reusability, its removal rate for Cu2+ and Pb2+ reached 50.21 % and 75.15 % after 5 adsorption–desorption cycles. And the removal rate of M-AT for Cu2+ and Pb2+ in domestic sewage treatment plant influent, tailings drainage, industrial wastewater was 82.80 %, 87.12 %, 85.12 % and 95.10 %, 91.20 %, 93.13 %, respectively. These results proved the feasibility of M-AT in treating Cu2+ and Pb2+ in wastewater. This study provides a new way for the resource utilization of fly ash. Applying solid waste to treat heavy metal-containing wastewater is a sustainable way to treat industrial waste.

Formulation of Novel Microbial Consortia for Rapid Composting of Biodegradable Municipal Solid Waste: An Approach in the Circular Economy

Urbanization and rapid industrialization have led to the escalation of municipal solid waste generation and accumulation. Composting is widely recognized as a sustainable solution for solid waste management. However, its long-term investment is considered a disadvantage. The present research study discusses the rapid biotransformation of solid waste into valorized compost. Bacteria were isolated from soil, solid waste, and leachate samples from open dump sites. From the 18 different bacterial consortia created using potential isolates, the five most promising consortia were selected based on concurrent different enzyme production. These selected consortia were incorporated into typical compost bins with Municipal Solid Waste (MSW). Daily monitoring of enzymatic activity, pH, conductivity, bulk density, moisture, and temperature, along with other composting parameters, was conducted. The study’s results demonstrated that consortium No. 5, comprising Bacillus haynesii, Bacillus amyloliquefaciens, and Bacillus safensis, exhibited significant (p<0.05) enzyme activity of cellulase, amylase, lipase and proteinase enzymes during composting compared to the control and other treatment setups. Consortium No. 5 also facilitated rapid and successful composting, as evidenced by significant alterations of composting parameters by exhibiting a shorter average composting time, reducing it from 110±10 days to 20±3 days, showcasing the potential applicability of formulated bacterial consortium as a sustainable and greener approach to the global solid waste problem. The novelty of this study lies in the isolation of local bacterial strains from open dump sites soil, MSW, and MSW leachate samples, which were then utilized in the composting organic fraction of MSW, enhancing the potential for effective waste management.

Environmental Aerobic Bacterial Associated with Infectious and General Solid Waste: Screening at the “Université des Montagnes” Teaching Hospital Waste Accumulation Sites

Background: Waste is a source of potentially dangerous microorganisms for users of healthcare facilities, and its accumulation is a risk factor for infectious agent dissemination. Objective: The first aim of the present study was to identify and quantify aerobic bacteria around solid waste accumulation sites at the “Université des Montagnes” Teaching Hospital. The second one was to assess bacteria susceptibility to common conventional antibacterial agents. Methods: Soil samples and airborne bacteria were collected at various distances from the target solid waste accumulation sites. Bacteria isolation and susceptibility tests were thereafter conducted according to standard protocols. Results: Isolated organisms (123 bacterial isolates) included Staphylococcus spp (48%), Gram-positive rods (32%) and Gram-negative rods (20%). Polymorphism and bacterial loads were highest at the sampling locations closer to the accumulation sites and decreased with increasing distances from these sites. Overall findings revealed that variations of polymorphism and bacterial loads is likely associated with anthropogenic activities. In addition, susceptibility rates for Staphylococcus were high. Conclusion: Together with the overall bacterial population distribution trends, the high susceptibility rates recorded deserve better understanding in future research initiatives for optimal hospital hygiene.

Public administration of domestic solid waste management as a direction for the protection of consumer rights

The scientific article is devoted to the public administration of solid household waste management as a direction of consumer rights protection. Attention was drawn to the positive aspects of public administration regarding the management of solid household waste as a means of protecting consumer rights (for example, in the Dnipropetrovsk region): the existence of the National Waste Management Strategy in Ukraine until 2030; availability of a regulatory and legislative framework in the field of management and handling of solid household waste; availability of "Methodical recommendations for the development of regional waste management plans”; existence of a solid household waste management program in the Dnipropetrovsk region for 2022-2024; positive experience of the EU and other developed countries in the field of effective management and handling of solid household waste; the presence of a solid household waste collection and disposal system; availability of municipal solid waste landfills; availability of enterprises for processing, processing and disposal of hazardous components of solid household waste; initiation of elements of separate collection of solid household waste; gradual formation of awareness among the population regarding the need to separate resource-valuable components from the general flow of solid household waste.
 It was concluded that the problematic issues in public administration regarding the handling of solid household waste as a direction of consumer rights protection (for example, in the Dnipropetrovsk region): the tendency to increase the scale of generation and accumulation of solid household waste; lack of a systematic approach to creating effective management and handling of solid household waste; insufficient funding of solid waste management and management; low level of implementation of previous regional solid waste management and handling programs; low level of utilization of resource-valuable components of solid household waste; lack of waste transfer stations and waste processing enterprises, etc.

Research on Utilizable Calcium from Calcium Carbide Slag with Different Extractors and Its Effect on CO2 Mineralization.

With the increasing accumulation of alkaline industrial solid waste, the mineralization of CO2 using alkaline industrial solid waste has broad application prospects. Carbide slag is highly alkaline and contains a large amount of calcium elements, making it an excellent material for CO2 mineralization. Our idea was to acquire qualified products and fast kinetics by integrating carbide slag utilization and carbon reduction. The reaction route was divided into two steps: calcium extraction and carbonization. In order to achieve efficient extraction of utilizable calcium, we selected NH4Ac as the extraction agent, which has the advantage of buffer protection and environmental friendliness due to being an acetate radical. The extraction efficiency of utilizable calcium exceeded 90% under the conditions of L/S 20:1 and NH4+/Ca2+ 2:1. In the carbonization process, the crystal forms of CaCO3 synthesized by direct carbonation, acid extraction, and ammonium salt were characterized. The formation mechanism of vaterite in ammonium solution and the influence of impurities (Al3+, Mg2+) on the crystal transformation were revealed. This study provides technical support for using alkaline industrial waste to prepare high-purity vaterite. Therefore, alkaline industrial waste can be efficiently and sustainably utilized through CO2 mineralization.