Waste Treatment Research Articles

N-doped lignin-based activated carbon aerogel derived from bamboo black pulp liquor for efficient removal of malachite green in wastewater.

In this study, a lignin-based aerogel (LA) was prepared through acid precipitation of BPBL, followed by sol-gel method and freeze-drying. Additionally, a one-step activation-carbonization method was used to acquire nitrogen-doped lignin-based activated carbon aerogel (NLACA). The adsorption and catalytic degradation performance for malachite green (MG) were examined. The specific surface area of NLACA after N-doping was 2644.5 m2/g. The adsorption capacity for MG was increased to 3433mg/g with the presence of nitrogenous functional groups on surface of NLACA compared without N-doping. Meanwhile, non-radical singlet oxygen is the primary active substance and degradation efficiency arrives at 91.8% after the catalytic degradation within 20min and it has good stability and reuse. Three possible degradation pathways during degradation were analyzed by LC-MS technique. The adsorption isotherm and kinetic data demonstrated conformity with both the Langmuir model and the pseudo-second-order kinetic model. The primary mechanisms of the adsorption for MG dyes on NLACA include hydrogen bonding, π-π interactions, attraction of electrostatic and pore filling. Hence, NLACA derived from BPBL acts as a cost-effective and high-performance adsorbent and catalyst for removal of MG in dye wastewater. This concept introduces an innovative approach of "treatment of waste with waste" for developing a low-consumption, high-efficiency dye wastewater treatment and provides significant reference to treatment dye wastewater.

Analysis of Solid Waste Treatment and Management in Typical Chinese Industrial Parks with the Goal of Sustainable Development and Future Suggestions

Solid waste disposal and management have become a global problem, which is particularly tricky in China with its large population and rapid urbanization. This study focused on the disposal status of multi-source solid waste as well as the park management of some typical cities of China. Firstly, the main technical methods for solid waste disposal were summarized as follows: landfill, incineration, anaerobic digestion and aerobic compost. Secondly, the network analysis method was applied to seek an optimized method for solid waste disposal and management. Thirdly, typical demonstration parks for solid waste disposal and management were analyzed to study their respective operating modes and strategies for synergistic development in terms of resources, environment and economy and to explore the sustainable development potential of the Guangdong–Hong Kong–Macao operating mode. The results showed that the collaborative disposal and recycling of solid waste are important for cities (especially megacities) to achieve resource conservation and environmental protection. The NIMBY effect and environmental pollution risks caused by decentralized construction could be reduced through the construction of circular industrial parks. Advanced technologies and the national policy for solid waste disposal and recycling in industrial parks of small–medium cities, large–medium cities and megacities were systematically analyzed so as to explore a self-operating management mode of industrial parks. Finally, reasonable suggestions, such as sharing, saving and cycling and propaganda education, as well as green and low-carbon solutions were put forward for solid waste disposal and management in typical industrial parks, effectively resolving the contradiction between economic development and environmental protection so as to help urban sustainable development.

Sustainable Waste Management and Service Quality Delivery in Nigeria

Waste disposal, collection and treatment is an indispensable facet in the developmental phases of rural and urban cities across the globe. The accumulation, disposal and treatment of waste in urban centers have become a predicament to both private and public stakeholders in Uyo metropolis, Akwa Ibom State, Nigeria. The objective of this study is to examine sustainable waste management and service quality delivery in Nigeria. The issues to be addressed by this study include; attitude of residents towards waste disposal, non-conformity with modern waste collection/treatment processes, and the waste management infrastructural gaps. The study adopted the 9 Development Band global theory of waste and development - using Integrated Sustainable Waste Management – ISWM approaches, with a model elucidating the effects of waste management on environmental footprint. Descriptive survey technique was adopted in which, questionnaire was administered to 384 respondents in the metropolis, as well as the conduct of in-depth interview to obtain additional information on issues that were not clarified in the structured questionnaire. Data collected from the field were collated and analyzed using Pearson Correlations Analysis Technique, to ascertain the relationship between the dependent and independent variables. The findings of the study revealed unwholesome and unsustainable approaches in waste disposal/management, and suggest effective service delivery approaches in line with the 9DB model ISWM. The study recommends that residents should dispose waste in line with established waste disposal procedures, waste management authorities should adopt efficient and sustainable waste collection and treatment approaches. If these suggestions are implemented; it could reduce the metropolis environmental footprint, mitigate on the current global climate change challenges, and promote the UN-SDG - 11 which anchors on the need for sustainable cities and communities.

Efficacy and Economic Benefits of Nano TiO2 Photocatalytic Advanced Oxidation Technology in Solid Waste Treatment

In order to assess the application value of nano TiO2 photocatalytic advanced oxidation technology in the field of solid waste treatment and improve the efficiency of waste disposal, this study investigates the preparation of TiO2/ZnIn2S4 composite photocatalysts using an in-situ growth method. Subsequently, this photocatalyst is applied to urban solid waste treatment schemes to degrade solid waste and organic pollutants in wastewater. The results indicate that, at a pH value of 7.5, the composite material exhibits the optimal photocatalytic degradation performance, achieving a degradation rate of 90%. Following the urban solid waste treatment scheme, the greenhouse gas emissions per ton of municipal solid waste range from 50 to 100 kg, resulting in a 90% reduction in greenhouse gas emissions. The calculated payback period for this waste treatment scheme is 5 years. The findings suggest that this treatment approach effectively reduces greenhouse gas emissions, enhances resource recovery rates, and demonstrates favorable economic benefits for application in small to medium-sized urban areas. This research provides valuable insights for the application of nano TiO2 photocatalytic technology in the field of solid waste treatment.

The relationship between energy provided and growth during severe wasting treatment.

Treatment of severe acute malnutrition aims at producing quick catch-up growth in children to decrease their short-term mortality risk. The extent to which catch-up growth is influenced by the amount of energy provided is unclear. This study assessed whether energy provided at admission is associated with catch-up ponderal growth among children with mid-upper arm circumference (MUAC) < 115 mm at admission. We conducted a secondary data analysis an operational cohort in Mali. The children were treated with a simplified protocol providing 1000 kcal/day of therapeutic food until MUAC ≥ 115 mm was achieved for two consecutive weeks and 500 kcal/day thereafter until discharge with MUAC ≥ 125 mm for two consecutive weeks. Linear mixed-effects regression models were fitted to assess the relationship between energy provided at admission (kcal/kg/day) with weight gain velocity (g/kg/day) (primary outcome), change in MUAC -for-age z-score and change in weight-for-age z-score. Unadjusted models and models adjusted for sex, age, seasonality and MUAC at admission were fitted. Both models included the study site as a random effect. A 10 kcal/kg/day increase in energy provided at admission was associated with increments in all outcomes; for weight gain velocity, the mean (95%CI) increment was 0.340 [0.326, 0.354] g/kg/day and 0.466 [0.446, 0.485] g/kg/day in the unadjusted and adjusted analysis, respectively. A positive relationship exists between energy provided at admission and catch-up ponderal growth in children with MUAC < 115 mm treated using a simplified protocol. Determining the ideal weight gain rate remains essential for assessing the benefits and risks of increased energy intake during treatment.

Multiphoton-Driven Photocatalytic Defluorination of Persistent Perfluoroalkyl Substances and Polymers by Visible Light.

Perfluoroalkyl substances (PFASs) and fluorinated polymers (FPs) have been extensively utilized in various industries, whereas their extremely high stability poses environmental persistence and difficulty in waste treatment. Current decomposition approaches of PFASs and FPs typically require harsh conditions such as heating over 400 °C. Thus, there is a pressing need to develop a new technique capable of decomposing them under mild conditions. Here, we demonstrated that perfluorooctanesulfonate (PFOS), known as a "persistent chemical," and Nafion, a widely utilized sulfonated FP for ion-exchange membranes, can be efficiently decomposed into fluorine ions under ambient conditions via the irradiation of visible LED light onto semiconductor nanocrystals (NCs). PFOS was completely defluorinated within 8-h irradiation of 405-nm LED light, and the turnover number of the C-F bond dissociation per NC was 17200. Furthermore, 81 % defluorination of Nafion was achieved for 24-h light irradiation, demonstrating the efficient photocatalytic properties under visible light. We revealed that this decomposition is driven by cooperative mechanisms involving light-induced ligand displacements and Auger-induced electron injections via hydrated electrons and higher excited states. This study not only demonstrates the feasibility of efficiently breaking down various PFASs and FPs under mild conditions but also paves the way for advancing toward a sustainable fluorine-recycling society.

Multiphoton‐Driven Photocatalytic Defluorination of Persistent Perfluoroalkyl Substances and Polymers by Visible Light

AbstractPerfluoroalkyl substances (PFASs) and fluorinated polymers (FPs) have been extensively utilized in various industries, whereas their extremely high stability poses environmental persistence and difficulty in waste treatment. Current decomposition approaches of PFASs and FPs typically require harsh conditions such as heating over 400 °C. Thus, there is a pressing need to develop a new technique capable of decomposing them under mild conditions. Here, we demonstrated that perfluorooctanesulfonate (PFOS), known as a “persistent chemical,” and Nafion, a widely utilized sulfonated FP for ion‐exchange membranes, can be efficiently decomposed into fluorine ions under ambient conditions via the irradiation of visible LED light onto semiconductor nanocrystals (NCs). PFOS was completely defluorinated within 8‐h irradiation of 405‐nm LED light, and the turnover number of the C−F bond dissociation per NC was 17200. Furthermore, 81 % defluorination of Nafion was achieved for 24‐h light irradiation, demonstrating the efficient photocatalytic properties under visible light. We revealed that this decomposition is driven by cooperative mechanisms involving light‐induced ligand displacements and Auger‐induced electron injections via hydrated electrons and higher excited states. This study not only demonstrates the feasibility of efficiently breaking down various PFASs and FPs under mild conditions but also paves the way for advancing toward a sustainable fluorine‐recycling society.

A new fractal pore-throat chain model for non-Darcy flow through porous media

Non-Darcy flow through porous media is of great significance in hydraulics, oil and gas engineering, biomedical science, chemical and civil engineering etc. However, it is difficult to fully grasp the nature of fluid flow through porous media from macroscopic scale alone. Based on the statistically fractal scaling laws of pore structures, a new fractal pore-throat chain model (FPTCM) for non-Darcy flow through the isotropic porous media is developed. The analytical expressions for the Darcy and non-Darcy permeability as well as non-Darcy coefficient are derived accordingly. In order to explore the local flow field of high-speed non-Darcy flow through porous media, the finite element method is also carried out on an equivalent pore-throat unit. The predicted permeability by FPTCM shows better agreement with present numerical results and available experimental data, compared with commonly used semi-empirical formulas including Kozeny-Carman and Ergun equations. It has been found that both Darcy and non-Darcy permeability as well as non-Darcy coefficient strongly relate to the pore structures of porous media. The non-Darcy permeability is positively correlated to porosity, pore fractal dimension and Darcy permeability, while it is negatively related to tortuosity fractal dimension and pore size range. The non-Darcy coefficient shows opposite correlation with these parameters. The present work can provide theoretical basis for oil and gas development, nuclear waste treatment, carbon dioxide geological sequestration etc.

Technological and economical analysis of the heat recovery system from flue gas in a thermal waste treatment plant

A heat recovery system from flue gas increases the overall efficiency of a district heating or CHP plant, as the system recovers the waste energy contained in the flue gas at the chimney outlet. This makes it possible to increase thermal energy production with the same fuel consumption. A method for calculating the thermodynamic parameters of municipal waste incineration plants was developed as part of the work carried out. The mathematical models prepared made it possible to analyse the impact of the heat recovery system from flue gas on technical and economic parameters and the environment, including, among other things, an estimate of the annual amount of heat recovered, the amount of additional electricity consumed, the amount of condensate treated, the estimated capital expenditure, operating profits and operating costs. The results of the analyses were the basis for designing and constructing a heat recovery system from flue gas equipped with a condensation heat exchanger for the municipal waste incineration plant in Cracow. The calculation results were compared with the measurement results obtained during the test run of the constructed installation.

Enhancing mechanical performance in SLS-printed PA12-slate composites through amino-silane treatment of mineral waste

The SLS additive manufacturing industry enables the development of products for diverse applications with distinct properties due to its excellent surface finish and ability to create varied part geometries, but it consumes high-performance materials with high acquisition costs. An extensive quarrying of stone leads to the accumulation of mineral residues, posing environmental hazards by contaminating soil and water when disposed of in landfills. The primary objective of the study was to incorporate mineral waste into the SLS technique and investigate the influence of its addition, along with a silane-based chemical treatment, on the mechanical performance of polymer-mineral composites (PA12-slate). Additionally, the feasibility of producing a highly loaded printed prototype, employing 50 wt% of mineral waste, was examined. Samples of PA12, PA12 blended with 50 wt% slate waste, and slate waste treated with silane underwent fabrication via selective laser sintering (SLS) and subsequent mechanical characterization, including tensile, flexural, and compressive tests. Additionally, the samples underwent accelerated aging using a QUV weathering tester, followed by mechanical characterization. The geometric accuracy, stability, and processing feasibility of these formulations were evaluated through SLS-printed composite prototypes utilizing PA12_50Sla_Si. It was found that the addition of 50% of slate to the PA12 presented mechanical properties decreasing compared to the printed PA12 only. However, an increase was verified when using silane-induced mineral bonding. The incorporation of mineral agents and silane enhanced the resistance of PA12 to aging. However, after aging, both tensile and flexural strength decreased across all printed samples. Nonetheless, this study showcased the feasibility of producing complex PA12-slate waste specimens containing up to 50 wt% of mineral waste using the SLS printing technique. Therefore, SLS presents itself as a viable means of adding value to this mineral waste.

Education of Waste Cooking Oil Processing into Aromatherapy Candles for 2 Junior High School Karanganyar Students

Waste is a complex problem and an important challenge for the sustainable development of a circular economy and can have social, environmental and economic impacts. This service aims to provide education to students so that students can have high knowledge and awareness of waste processing and can utilize used cooking oil waste to make aromatherapy candles. This service was carried out at 2 Junior High School Karanganyar on Thursday, June 20 2024. The service method was socialization and direct practice in making aromatherapy candles. Students have the skills and are successful in making aromatherapy candles according to the material presented by the speaker. This activity succeeded in increasing students' awareness and knowledge regarding household waste management. Students showed high enthusiasm in following the process of processing used cooking oil waste into useful products such as aromatherapy candles, while also expressing their creativity in this process. Positive support from teachers also contributed to the successful implementation of this waste treatment.

Sosialisasi Kewirausahaan pada UMKM Ecoprint KWT Pandan Arum Kjang untuk Meningkatkan Usaha Ekonomi Kreatif di Kelurahan Pajang

Ecoprint KWT Pandan Arum 48 Kjang is one of the entrepreneurial potentials that exists in Kelurahan Pajang. This effort was created at the same time as the Climate Village Race (PROKLIM). But the awareness of this effort and the marketing strategy used is still not optimal, because only through mouth-to-mouth and WhatsApp. Therefore, we strive to provide understanding related to product innovation, waste treatment, as well as the use of digital technology in the world of business, that is, digital marketing. The purpose of the submission is to improve skills, learn how to manage waste properly, and reach a broader market for the entrepreneur Ecoprint KWT Pandan Arum 48 Kjang. We realize these activities through the socialization of entrepreneurship. Thus, through this socialization, it is expected to increase competitiveness, expand the reach of the market, and make Ecoprint KWT Pandan Arum Pajang a sustainable business.

Microbial electrochemical enhanced composting of sludge and kitchen waste: Electricity generation, composting efficiency and health risk assessment for land use

To realize the energy and resource utilization from organic solid waste, a two-phase microbial desalination cell (TPMDC) was constructed using dewatered sludge and kitchen waste as the anode substrate. The performance of electricity generation and composting efficacy was investigated, along with a comprehensive assessment of the potential health risks associated with the land use of the resulting mixed compost products. Experimental outcomes revealed a maximum open-circuit voltage of 0.893 ± 0.005 V and a maximum volumetric power density of 0.797 ± 0.009 W/m³. After 90 days of composting enhanced by microbial electrochemistry, a significant organic matter removal rate of 31.13 ± 0.44 % was obtained, and the anode substrate electric conductivity was reduced by 30.02 ± 0.04 % based on the anode desalination. Simultaneously, there was an increase in the content of available nitrogen, phosphorus, and potassium, as well as an improvement in the seed germination index. The forms of heavy metals shifted from bioavailable to stable residual states. The non-carcinogenic hazard index (HI) values for heavy metals and polycyclic aromatic hydrocarbons (PAHs) during the land use of compost products were less than 1, and the total carcinogenic risk (TCR) values for heavy metals and PAHs were below the acceptable threshold of 10−4. The occupational population risk of infection from five pathogens was higher than that of the general public, with all risk values ranging from 8.67 × 10−8 to 1, where the highest risk was attributed to occupational exposure to Legionella. These outcomes demonstrated that the mixture of dewatered sludge and kitchen waste was an appropriate anode substrate to enhance TPMDC stability for electricity generation, and its compost products have promising land use suitability and acceptable land use risk, which will provide important guidance for the safe treatment and disposal of organic solid waste.

Solid waste management and resource recovery during the 4-crew 180-day CELSS integrated experiment

In order to explore the management and treatment methods of solid waste in the Controlled Ecological Life Support System (CELSS) of future lunar bases, during the 4-crew 180-day integrated experiment, the Solid Waste Management and Treatment System (SWMTS) was built, in which the treatment of recyclable solid waste such as inedible plant parts and human excrement was completed through a combination of biological aerobic composting and high-temperature oxidation. Basic data on the types and amounts of solid waste generated during the 4-crew 180-day experiment mission were obtained. There were six types of solid wastes, including the work support wastes, the household support wastes, the plant cultivation wastes, the plant-based wastes, and crew feces. The daily average production was 0.67, 1.4, 0.32, 8.48, 0.534 kg/d, respectively. The proportion of plant-based wastes was high as 74.3 %, indicating that it was the most important part. By closed-loop air drying and graded crushing, all 1526.97 kg of plant-based waste was treated, with water recovery (about 1163.87 kg), as well as volume reduction and stabilization treatment. By incineration and aerobic composting treatment, 67.3 % (244.4 kg) of the plant-based wastes (dry weight) and all of the feces (96.26 kg) were converted, providing 339.54 kg carbon dioxide for plant growth. And 90.6 kg organic fertilizer was obtained. The fertilizer was highly mature, met safety requirements, and effectively improved lettuce yield. The recycling rate of renewable solid waste during the experiment reached 89.8 %. The efficient circulation of solid waste had been achieved during the 4-crew 180-day integrated experiment. The long-time experimental results have shown that the established solid wastes management and treatment system can timely treat biomass solid waste such as inedible parts of plants and crew feces, achieve timely recovery of water in such solid waste, and recycle carbon and other elements, which effectively improved the material closure of the system and ensured the successful 4-crew 180-day experiment. This work also maybe lay the foundation for the construction and operation of an ecological life support system for future lunar bases.

QUANTIFICATION OF CARBON POTENTIAL OF CONSTRUCTION WASTE TREATMENT: A CASE STUDY OF GUANGZHOU, CHINA

ABSTRACT Emission reduction in the construction sector is essential for China to achieve its carbon peaking and carbon neutrality goals. Construction waste recycling represents an important step in reducing the construction industry’s carbon emissions; however, construction waste recycling potential has received little attention from the industry to date. This paper adopts the Life Cycle Assessment method, constructs a carbon potential quantification formula for different construction waste treatment modes, and evaluates the economic benefit of these methods. The study’s main results are as follows. (1) For each unit (t) of construction waste disposal, the carbon potential of close-range off-site recycling is the lowest, that of public landfill is the highest, and that of recycling is intermediate. (2) The economic benefit evaluation shows that under the same conditions, the lowest total disposal cost for construction waste per unit (t) is via recycling and resourcing, indicating that this approach combines economic benefits, environmental friendliness, and sustainability. (3) Eco-friendly bricks produced by construction waste recycling have reduced carbon potential requirements compared to traditional bricks; thus, the construction waste treatment process plays a successful role in reducing carbon potential. This study’s conclusions enrich and improve the theory of construction waste resource management and can be used as a reference basis for the government to formulate emission reduction strategies for the construction industry and provide guidance for enterprises related to construction waste recycling.

Comparative analysis of water quality index and river classification in Kereh River, Penang, Malaysia: Impact of untreated swine wastewater from Kampung Selamat pig farms.

The Kereh River in Penang, Malaysia, has faced severe pollution for over 40 years due to untreated wastewater from swine farms in Kampung Selamat, discharged via stormwater drains. Despite official claims that all 77 swine farms treat their wastewater to meet regulatory standards, local non-governmental organizations and villagers have challenged this, though their concerns lack scientific backing. This study evaluates the river's water quality by analyzing samples from upstream (US), midstream (MS), and downstream (DS), and from Parit Cina-Parit Besar, a conduit for untreated swine wastewater. Fourteen parameters were measured against Malaysia's National Water Quality Standards (NWQS). Significant differences were found in six parameters: ammonium nitrogen (AN), biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), total suspended solids (TSS), and oil and grease (OG). While Dunn's post hoc pairwise comparison showed no significant differences among river segments, mean values indicated increased pollution downstream, particularly after the convergence with untreated swine wastewater. River classification worsened, with water quality index dropping from 69.88 ± 11.37 score (Class III) US to 38.49 ± 12.74 and 50.44 ± 3.14 scores (Class IV) MS and downstream, respectively. A significant positive correlation between E. coli and AN (r = 0.71, p < 0.01) suggests a common point source pollutant, particularly the untreated swine wastewater. The river exhibits low oxygen levels and high organic matter and nutrient concentrations, especially MS and downstream, highlighting substantial ecological and public health risks. Effective enforcement of waste treatment regulations and enhanced monitoring are crucial for mitigating pollution and restoring the river's ecosystem. Collaboration between authorities and pig farmers is essential to improve water quality and maintain the river's ecological balance. PRACTITIONER POINTS: Severe Kereh River pollution: Untreated swine wastewater from Kampung Selamat pig farms, primarily via Parit Cina-Parit Besar, has degraded the river for over 40 years. Regulatory non-compliance: Despite official claims, untreated swine wastewater continues to pollute the river, challenging regulatory standards. Significant pollution indicators: Elevated levels of AN, BOD, COD, DO, TSS, OG, and E. coli signal severe pollution midstream and downstream. Water quality index drop: WQI scores classify midstream and downstream sections as polluted, indicating worsening conditions downstream. Urgent need for action: Enforcing regulations, improving wastewater treatment, and relocating pig farms are crucial for restoring the Kereh River.

Comparison of mesophilic and thermophilic anaerobic digestion of food waste: Focusing on methanogenic performance and pathogens removal

Food waste (FW) is a valuable and sustainable resource for anaerobic digestion (AD). However, mesophilic AD, commonly used, poses risks associated with pathogenic microorganisms, potentially limiting the safe utilization of digestion by-products. This study aimed to evaluate and compare methane production efficiencies and pathogen reduction capabilities between mesophilic and thermophilic AD processes. Methane production was assessed in batch and continuous operations under thermophilic conditions, resulting in methane yields of 380 and 360 mL/g VS, representing increases of 5.56 % and 22.44 % respectively compared to mesophilic conditions. Pathogen removal efficiency analysis showed that thermophilic AD achieved Escherichia coli elimination rates between 98.9 % and 99.9 %, with higher removal rates for Salmonella ranging from 77.9 % to 99.8 % compared to mesophilic processing. Overall, results from batch and continuous experiments demonstrate that thermophilic AD not only enhances methane production but also significantly improves pathogens reduction, offering a more effective approach for managing FW in AD systems. The findings of this study enhance the scientific understanding of anaerobic digestion technology in food waste treatment applications and provide crucial technical support and decision-making guidance for environmental management and renewable energy production.

Hierarchical V2O3 spiny hollow nanosphere for efficient adsorption of precious metal ions in complicated matrices

Treatment of precious metals in electronic waste has attracted tremendous attention and is essential for both environmental protection and resource sustainable development. In this study, a novel adsorbent for precious metal ions, V2O3 spiny hollow nanospheres (p-V2O3 SHN), was synthesized through a one-step hydrothermal-assisted methodology for the adsorption of Au(III), Ag(I), Pd(II), and Pt(IV) from the leaching solution of electronic waste. The results reveal that the p-V2O3 SHN hierarchy was successfully constructed with a hollow structure and dense spiny morphology. The prepared p-V2O3 SHN can effectively remove precious metal ions such as Au(III), Ag(I), Pd(II), and Pt(IV), with the selective capture order being Au(III) > Ag(I) > Pt(IV) > Pd(II) > other metal ions. This superior adsorption capability can be attributed to the multi-diffusible, intermingled composition, and numerous active sites decorating the p-V2O3 SHN hierarchy, facilitating the uptake of Au(III), Ag(I), Pd(II), and Pt(IV) ions from electronic waste. The Langmuir model provided a better fit for the uptake process, revealing maximum uptake capacities of 833.33 mg/g for Au(III), 370.37 mg/g for Ag(I), 77.51 mg/g for Pd(II), and 42.01 mg/g for Pt(IV) on p-V2O3 SHN. Remarkably, p-V2O3 SHN exhibited a robust affinity for the adsorbate due to the presence of surface defects and reduction. The new p-V2O3 SHN also demonstrated good reusability for three sorption cycles, highlighting its potential for electronic waste treatment. Due to its facile synthesis and excellent efficiency, hierarchical p-V2O3 SHN presents itself as a promising candidate for the selective uptake of Au(III), Ag(I), Pt(IV), and Pd(II) from electronic waste.

Geology, mineralogy, geochemistry and genesis of volcano-sedimentary hosted Lake Abiyata diatomite in central main Ethiopian Rift

The Abiyata Diatomite deposit is located in the Main Ethiopian Rift, which is characterized by strong extensional tectonics. The deposit is mostly made up of diatomaceous earth, which is a sedimentary rock made up of the fossilized remnants of diatoms, which are tiny algae. Diatomite's geological, geochemical, and mineralogical features, as well as its formation, are discussed in this research. To characterize diatomite from Abiyata, chemical, mineralogical, technological, and micro paleontological examinations were conducted on samples collected from outcrops and stream sections. The XRD characteristic peaks of diatomite demonstrate that it is primarily made up of Opal A silica, however certain crystalline phases were discovered in adequate amounts. Quartz and feldspar were the predominant crystalline phases, with lesser amounts of Calcite, Cristobalite, Illite, Mordinite, Wairakite, Halloysite, Clinoaptilolite, Adularia, and Tridymite. From SEM photomicrographs diatomites are primarily formed of benthic freshwater diatom species such as Staurosirella pinnata, Staurosira construens, Pseudostaurosira brevistriata, Epithemia Sorex and surirella pinnata. Diatom species, sedimentary profile sections and mineralogical data suggest that diatomite was deposited in lacustrine-type freshwater shallow lake environment. Chemical data obtained from 10 diatomite samples show that while silica is the bodybuilding material for diatomite. i.e., Silica (SiO2), 76.9 %; Alumina (Al2O3), 3.49 %; Sodium Oxide (Na2O), 1.52 %; Potassium Oxide (K2O), 1.107 %; Iron Oxide (Fe2O3), 1.1 %; Loss on ignition (LOI) 13.7 and other oxides are below 1 %. Studies from technological properties like physical tests, chemistry, and mineralogy and micropaleontology of Abiyata diatomite suggest that calcined diatomite can be used for waste treatment processes in the filter aid industry and as filler material.

The role of the informal sector in waste sorting, collection, and recycling in Tan An City, Long An

Abstract Despite efforts to adopt at-source waste separation, Tan An city’s solid waste management is under strain due to a lack of infrastructure. The demand of the scrap recycling market has resulted in the forming of a network of informal scrap trading establishments everywhere. Informal garbage workers efficiently collect (pick, buy) scraps from homes, grocery stores, businesses, workplaces, schools, parks, dump sites, and landfills. This boosts waste segregation at the source. Therefore, in Tan An city, most households separate recyclables for sale to informal waste workers. According to survey results, there are approximately 247 informal waste workers in Tan An City engaged in recyclables collection at a daily average rate of 69.66 kilograms per person. Thus, the total quantity of recyclables collected by this sector is approximately 17,260 kg per day, contributing to the daily diversion of 11.4% of waste from landfills. It helps that the annual savings to the city are estimated at VND 2.75 billion for waste collection and transportation and VND 2.47 billion for waste treatment. It also contributes to the creation of jobs, and the reduction of plastic emissions into the ocean because approximately 28.39% of recyclables are plastic waste, and the reduction of approximately 3.076 tons of CO2 emissions into the atmosphere if this amount of waste is transported to a landfill. This study could initiate further research to find a way to introduce modern initiatives that aim to improve working conditions and the environmental impact of the informal sector and include the informal sector into the EPR scheme as their integration is related to social, labor, health, economic, and other issues.