Waste Technology Research Articles

Research progress on high-value utilization technology of sludge solid waste in China

Research progress on high-value utilization technology of sludge solid waste in China

Development of Technologies for Processing Polypropylene Foil Waste and Their Use in the Production of Finished Products

This work aims to assess the possibility of using packaging industry waste to modify polypropylene products (PPs). The products were made in the form of extruded foil and injected samples. The products were produced using regranulate made of polypropylene cast foil. Maleic anhydride-modified polypropylene (MAPP) and polyolefin elastomer (POE) with a glycidyl ester functional group were used to modify the polypropylene. The samples were produced based on 50% foil waste reground and 50% pure PP. The rheological properties of the blends were assessed using the melt mass flow rate (MFR) technique; thermal properties using the differential scanning calorimetry method (DSC). The products manufactured using the injection molding method were subjected to an analysis of mechanical properties, such as tensile strength and impact strength. Also, in the case of film samples, tensile strength was assessed. Color-change assessments with CIE L*a*b* were carried out for all materials. Injection-molded products based on recycled metallized cast foil showed favorable mechanical properties such as tensile strength (1 MAPP = 26.7 MPa; 2 MAPP = 27.1 MPa), which was higher than the original material (cPP = 20.7 MPa). Also, for the films produced from regrind, the tensile strength was at a level similar (1 MAPP = 24.6 MPa; 2 MAPP/POE = 25.1 MPa) to the films extruded from virgin materials (cPP = 24.9 MPa). The introduction of a POE additive to the blends resulted in increased impact strength (1 MAPP/POE = 31 kJ/mol; 2MAPP/POE = 18 kJ/mol; 3 MAPP/POE = 11 kJ/mol) in relation to unmodified samples (cPP = 7 kJ/mol). The introduction of a POE additive to the tested mixtures improved the impact strength of the injected products by almost 4 times for sample 1 MAPP/POE and 2.5 times for sample 2 MAPP/POE in comparison to virgin cPP. These studies confirmed that foil waste can be successfully used to modify polypropylene products shaped both in the injection and extrusion processes.

Synthesis of La2Ti2O7 nanoscale powder and ceramics based on it by sol-gel and spark plasma sintering

The application of ceramics as matrices for the immobilization of radionuclides for the purpose of their safe long-term disposal or beneficial use is being studied with an emphasis on phase stability, structural integrity, hydrolytic stability, etc. In this work, a combined approach was investigated, based on the sol-gel citrate synthesis of nanosized La2Ti2O7 powder and its subsequent spark plasma sintering to produce dense ceramics. The phase composition and structure of the nanosized La2Ti2O7 powder and ceramic samples based on it, obtained in the temperature range of 900–1300 °C, were studied by XRD and SEM. It has been shown that the powder synthesis conditions ensure the formation of nanosized crystalline La2Ti2O7 grains, whose consolidation under spark plasma heating conditions proceeds with a change in the phase composition from single-phase La2Ti2O7 of monoclinic structure to orthorhombic with an admixture of LaTiO3 at temperatures above 1200 °C. It was revealed that the change in the ceramic structure is accompanied by the formation of non-porous and defect-free monolithic samples. It was determined that such a change leads to an increase in relative density (81.3–95.7%) and compressive strength (78–566 MPa) of the ceramic samples. However, the hydrolytic stability of the ceramics decreases, as indicated by an increase in the leaching rate of La3+ from 10–7 to 10–5 g/cm2·day. The obtained results are useful for the systematic study of materials suitable for immobilization technologies of radioactive waste in ceramics.

A life cycle-based comparison study of sludge recycling technology incorporating subjective and objective evaluations

Inadequate land capacity and low sludge recycling rates have become a major global environmental challenge. Low organic sludge content and inadequate waste management policy mean that there is an urgent need to improve sludge solutions in China, which has the world's largest WWT capacity. Decision-makers face difficulties in selecting sustainable sludge-to-resource technologies given the existence of multiple social, environmental and economic objectives, and also in optimizing the allocation of sludge between different available technologies. In this paper we used a combined analytic hierarchic process (AHP) and entropy weight (EW) method to evaluate four recycling technologies: aerobic composting (AC), dry-incineration (DI), hydrothermal carbonization (HTC) and pyrolysis (PY), in terms of five economic, environmental and land resource indicators. The results showed that human toxicity was viewed as the most important indicator, while economic value of sludge product was the least important. HTC had the best overall performance of the evaluated technologies while PY was the least attractive. However, all four sludge recycling technologies showed greater potential for reducing carbon emissions and human toxicity than landfilling when sludge dewatering was included. Sensitivity analysis showed that adjustments to AHP weights only had a limited impact on the technical ranking. Finally, the result was further verified by a particle swarm optimization algorithm. Considering capacity constraints, the optimal proportion of the four technologies was found to be 44.9%, 42.7%, 0 and 12.4% for HTC, DI, PY and AC respectively. The paper demonstrates the effectiveness of combining subjective and objective methods to evaluate multiple indicators, providing decision-makers with a practical analysis framework for waste technology selection.

Value-added utilization technologies for seaweed processing waste in a circular economy: Developing a sustainable modern seaweed industry.

The global seaweed industry annually consumes approximately 600,000 tons of dried algal biomass to produce algal hydrocolloids, yet only 15-30% of this biomass is utilized, with the remaining 70-85% discarded or released as scum or wastewater during the hydrocolloid extraction process. This residual biomass is often treated as waste and not considered for further commercial use, which contradicts the principles of sustainable development. In reality, the residual algal biomass could be employed to extract additional biochemical components, such as pigments, proteins, and cellulose, and these ingredients have important application prospects in the food sector. According to the biorefinery concept, recycling various products alongside the principal product enhances overall biomass utilization. Transitioning from traditional single-product processes to multi-product biorefineries, however, raises operating costs, presenting a significant challenge. Alternatively, developing value-added utilization technologies that target seaweed waste without altering existing processes is gaining traction among industry practitioners. Current advancements include methods such as separation and extraction of residual biomass, anaerobic digestion, thermochemical conversion, enzymatic treatment, functionalized modification of algal scum, and efficient utilization through metabolic engineering. These technologies hold promise for converting seaweed waste into alternative proteins, dietary supplements, and bioplastics for food packaging. Combining multiple technologies may offer the most effective strategy for future seaweed waste treatment. Nonetheless, most research on value-added waste utilization remains at the laboratory scale, necessitating further investigation at pilot and commercial scales.

Upcycling end-of-life carbon fiber in high-performance CFRP composites by the material extrusion additive manufacturing process

Each year, a significant amount of waste is produced from carbon fiber polymer composites at the end of its lifecycle due to extensive use across various applications. Utilizing regenerative carbon fiber as a feedstock material offers a promising and sustainable approach to additive manufacturing based on materials. This study proposes the additive manufacturing of recycled carbon fiber with a polyamide-12 polymer composite. Filaments of recycled carbon fiber-reinforced polyamide-12 (rCF-PA12) with different recycled carbon fiber contents (0%, 10%, and 15% by weight) in the polyamide-12 matrix are developed. These filaments are utilized for 3D printing of specimens by using various infill density parameters (80% and 100%) on a fused deposition modeling 3D printer. The study examined how the fiber content and infill densities influenced the flexural performance of the printed specimens. Notably, the part containing 15 wt% recycled carbon fiber (rCF) composites showed a significant improvement in flexural performance due to enhanced interface bonding and effective fiber alignment. The results indicated that reinforcing the printed part with 10% and 15 wt% recycled carbon fiber (rCF) improved the flexural properties by 49.86% and 91.75%, respectively, compared to the unreinforced printed part under the same infill density and printing parameters. The investigation demonstrates that the additive manufacturing-based technique presents a potential approach to use carbon fiber-reinforced polymers waste and manufacture high-performance engineering, economic, and environmentally friendly industrial applications with the complicated design using different polymer matrices.

ИССЛЕДОВАНИЕ ТЕРМОДЕФОРМАЦИОННЫХ СВОЙСТВ ПОЛИТЕТРАФТОРЭТИЛЕНА

In this paper, comparative studies of the thermal and thermal deformation characteristics of PTFE presses obtained from the initial powder and chips are carried out. The work carried out comprehensive studies using methods of differential thermal and thermomechanical analyses. The results obtained are important for the development and improvement of technologies for processing polymer waste.

Phytocapping for Municipal Solid Waste Landfills: A Sustainable Approach

This paper reviews the historical developments in landfill technology and its drawbacks. It introduces phytocapping, in light of previous research, as a promising, eco-friendly and sustainable technology for municipal solid waste (MSW) landfill covers in order to reduce landfill gas and leachate generation. This paper highlights the challenges to successful phytocapping, such as selection criteria for appropriate plants and growth media, and the importance of new research into overcoming these challenges. It also presents a database of plants used in landfill phytocapping studies worldwide. In addition, the performance, economics, and sustainability of phytocapping technology are evaluated in comparison to ordinary MSW landfill methods.

TG-FTIR-Py-GCMS analysis and catalytic pyrolysis mechanism of textile waste by red mud catalyst for liquid fuel production

The substantial generation of textile waste (TW) and red mud (RM) has resulted in significant resource wastage and environmental challenges. Co-utilization technology of solid waste is an effective approach to improve waste utilization efficiency. In this study, RM catalytic pyrolysis experiments of TW were conducted using TG-FTIR and Py-GC–MS for liquid fuel production, and TW and RM were recycled simultaneously. At the optimal experimental conditions (temperature of 600 °C and feed catalyst ratio of 2:1), the tar yield and higher heating value (HHV) of TW pyrolysis catalyzed by RM were 73.43 wt% and 32.34 kJ/g, respectively. Additionally, experiments on the pyrolysis of various TW types revealed that LDPE and PP are suitable for tar production, while cotton, nylon, and PET are more suitable as feedstock for syngas production. The RM catalytic pyrolysis mechanism of textile waste is that Fe2O3 in RM exhibits significant catalytic activity in enhancing tar and syngas yields. However, during the catalytic process, Fe2O3 undergoes reduction to Fe3O4, resulting in diminished catalytic performance of the RM. After five cycles of use, the RM essentially lost its catalytic activity due to the accumulation of char and tar. All experimental findings of this study could offer an effective guideline for TW recycle and promoting RM utilization toward the waste-to-energy circular economy.

Experimental Assessment of Energy Potentials from Tea Wastes as a Source of Energy: A Case of Itona Tea Factory in Tanzania

Tea processing is an energy-intensive process. However, high agricultural productivity and subsequently the growth of the green revolution have been made possible only by a large amount of energy inputs, especially those from fossil fuels, wood fuels, and electricity. With recent price rise and scarcity of these fuels there has been a trend towards use of alternative energy sources such as waste (agricultural waste) to energy that could solve both energy and environment issues. Moreover, these energy resources have not been able to provide an economically viable solution for agricultural applications so long as they seem to contain amount of energy which can be source of energy to be used in various factories in rural areas through gasification process. A gasifier is normally fuel specific system and it is tailored around a fuel rather than the other way round. Hence, this paper presents an experimental assessment of energy potentials from tea wastes available at Itonaa Tea Factory for tea drying processes as important data for agricultural wastes. The experimental measurement of energy potential from tea wastes was done using bomb calorimeter, muffle furnace and energy balances to determine calorific value moisture content and energy potentials of tea waste respectively. The findings indicate that the combined energy potential of factory and garden tea waste was found to be 2.78x10<sup>8</sup>kWh, and corresponding electrical energy was estimated to be 2.78x10<sup>7</sup>kWh which is enough for tea drying process in tea manufacturing plant. The total energy used in the production of tea was discovered to be equal 3.5 - 7.5 kWh/kg of made tea. Thus, total energy consumption (4.5 kWh/kg of made tea) for processing of 9.6 x 10<sup>6</sup> kg of tea from 4.5 x 10<sup>3</sup> hectares of tea plantation in Mufindi for the period of 2021-2022 was 4.32x10<sup>7</sup> kWh. Thus, with the proper utilization of energy conversion technology of tea waste, part of the energy requirement in processing of tea could be met reducing environmental challenges associated with both wood fuel burning and tea waste disposal.

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.

Data-driven multi-objective intelligent optimal control of municipal solid waste incineration process

The municipal solid waste incineration (MSWI) process has become the primary technology for municipal solid waste (MSW) treatment worldwide due to its advantages of harmlessness, reduction, and resource recovery. However, the automatic combustion control (ACC) system developed in developed countries are often not effectively applicable to other countries, particularly China, due to regional differences in MSW composition. To achieve intelligent development of MSWI plants, it is crucial to develop intelligent optimal control technology tailored to national conditions to reduce comprehensive pollutant emission concentration (CPEC) and improve combustion efficiency (CE). This article proposes a data-driven multi-objective intelligent optimal control strategy. Firstly, based on the analysis of the whole process, the Tikhonov regularization-least regression decision tree (TR-LRDT) algorithm is used to establish a MSWI whole process model, incorporating serial controlled objects and parallel pollutant indicators, to support a multi-objective optimization model. Then, leveraging the ACC system and expert experience, a multi-input multi-output loop controller is established using the single neuron adaptive PID (SNA-PID) algorithm to achieve stable control of key controlled variables. Next, a mutation crossover strategy and termination condition are integrated with the multi-objective particle swarm optimization (MOPSO) algorithm to solve the multi-objective optimization model, and domain expert rules are applied to determine the optimal setpoints for key controlled variables in the Pareto front, aiming to reduce CPEC and improve CE. Finally, the effectiveness of the proposed intelligent optimal control strategy is validated using actual data. The experimental results demonstrate that this strategy not only maintains the stability of key controlled variables but also decreases CPEC by 1.82% and increases CE by 2.38%, laying a foundation for further research into intelligent optimization control of the MSWI process. Further, the software system based on the proposed strategy is developed and validated on a hardware-in-loop simulation platform.

Evaluation of Waste Management in XYZ University Area in Yogyakarta

The increasing volume of waste is driven by several factors, including population growth, urbanization, and changes in lifestyle. This rise in waste generation has outpaced the capacity of available landfill space, leading to the improper accumulation of unmanaged waste. This study aims to evaluate the current waste management practices, analyze the waste generation and composition, and propose an effective waste management scenario. A quantitative descriptive analysis approach was employed, utilizing waste generation and composition data measured in accordance with the Indonesian National Standard (SNI) 19-3964-1994. The proposed waste management scenario is aligned with the guidelines outlined in Sleman Regency Regulation No. 4 of 2015. The operational techniques for managing waste include stages such as storage, collection, transportation, and treatment, which are outsourced to a third party. The findings of this study indicate that the waste at eight sampling points averaged 359,250 kg/day and 4,058 m³/day. The waste composition is predominantly organic (2.48%), paper and cardboard (12.4%), and other types of waste (11.07%). The proposed processing methods focus on utilizing technologies for organic waste and residue treatment, such as Masaro technology.

Эффективность использования куриного помета при выращивании зерна озимой пшеницы

In this paper, the possibility and effectiveness of using chicken manure as an organic fertilizer "Soil improver (UP-1)" is studied. "Soil improver (UP-1)" was obtained by adding the plant growth regulator "Mephosphone" to chicken manure. The drug "Mephosphone" is intended for the cultivation of grain crops, as well as the production of organic products. Experimentally, the prospects of using the drug "Mephosphone" to accelerate the processing of organic waste have been revealed. As a result of the research, field data were obtained on the cultivation of winter wheat of the Kazanskaya 560 Elite variety in the fields of JSC Agrofirma Ak Bars - Pestretsy. The introduction of chicken manure - "Soil improver (UP-1)", treated with the drug "Mephosphone" was carried out according to the described method. The local variety of winter wheat "Kazanskaya 560" Elite with a seeding rate of 280 kg/ha was used as an experimental crop. The predecessor was perennial herbs. Before the experiment and after harvesting, soil was selected for analysis from both experimental fields with an area of 300 hectares from 6 random plots at a layer depth of 0-20 cm. As a result of field tests, an increase in the yield of grain of the Kazanskaya 560 Elite variety was recorded when applying chicken manure. In the experimental plots, the yield was 33.5 and 36.0 c/ha. The grown grain with the use of chicken manure treated with the preparation "Mephosphone" meets the basic quality requirements and is practically not inferior to the grain of the control group, which allows it to be freely used for processing into flour of proper quality. Analysis of the indicators of experimental soil samples shows that they do not exceed the requirements of scientific and technical documentation. Thus, the resulting soil is safe for humans and agricultural production. The proposed technology for processing poultry waste will improve the environmental situation around modern poultry farms, reduce the use of unprocessed chicken manure as fertilizers, replacing it with higher-quality and environmentally friendly organic fertilizers formed as a result of anaerobic disposal of manure.

The Implementation of Lean Manufacturing on Zero Waste Technologies in the Food Processing Industry: Insights from Food Processing Companies in Kosovo and North Macedonia

This study aims to investigate the impact of lean manufacturing (LM) practices in the food processing (FP) industries of Kosovo and North Macedonia. It focuses on examining the effects of LM practices on operational performance metrics and evaluating the challenges and opportunities in integrating lean principles with zero waste (ZW) technologies and sustainability objectives. A qualitative multiple case study approach was used to examine nine case studies from companies in Kosovo and North Macedonia, with four companies from Kosovo and five from North Macedonia. Semi-structured interviews, guided by themes derived from a comprehensive literature review, facilitated in-depth discussions on lean practices and their influence on operational metrics and ZW technologies. For analyzing the qualitative data, a thematic analysis approach was employed, involving a multi-step coding process that ensured a comprehensive exploration and interpretation of the data. The thematic analysis uncovered that LM practices, such as Just-In-Time (JIT), Total Productive/Preventive Maintenance (TPM), Statistical Process Control (SPC), and employee involvement, considerably improve efficiency, quality, and responsiveness. The results demonstrate a close relationship between LM practices and sustainability goals, especially in waste reduction and resource optimization. Identified challenges include organizational resistance to change and resource constraints, while opportunities for improvement were noted in employee involvement, supplier engagement, and continuous improvement initiatives. This study underscores the potential of LM methodologies to boost operational performance, foster sustainability, and tackle specific challenges within the industry, offering key insights for enhancing sustainable food production in both Kosovo and North Macedonia.

Study on mechanical properties and microstructure of metakaolin-slag-calcium carbide residue synergistic solidifying waste engineering mud

Utilizing MSC composite materials (M-Metakaolin(MK)), S-Slag, C-Calcium carbide residue (CCR)), the waste engineering mud produced through the drilling and grouting pile construction method was solidified.Through the analysis of unconfined compressive strength (UCS), X-ray diffraction (XRD), and scanning electron microscope (SEM) on solidified engineering mud test blocks, the influence of complex factors such as slag content, CCR content, and curing time on the solidification efficiency of engineering mud was investigated, and the microscopic mechanism was analyzed.Concurrently, supplementary tests were carried out to ascertain the pH and water content of the cured mud.The results indicated that the 7-day unconfined compressive strength of cured mud specimens could achieve 3 MPa when incorporating 12 % MK, 8 % slag, and 6 % CCR.The optimal pH for the curing mud is determined to be 11.25, correlating with a water content of 84 %.The destructive strains corresponding to the peak stresses of the cured mud at different curing times ranged from 1.6 % to 2.5 % and generally decreased with increasing peak stresses.The XRD and SEM analyses have demonstrated that the enhancement in the strength of the cured mud can be attributed to the processes of hydration and polymerization, resulting in the generation of gel products such as calcium silicate hydrate (CSH) and aluminosilicate-Na hydrate (NASH). These products are responsible for the adsorption of clay and bentonite particles, thereby efficiently occupying the structural voids.The research findings have the potential to provide theoretical support for the development of environmentally friendly and low-carbon MSC gelling materials, as well as their application in soil reinforcement, notably in the context of engineered mud solidification.

Synergetic effects during co-pyrolysis of waste textiles and Ca/Fe-rich industrial sewage sludge: Reaction kinetics and product distribution

Co-pyrolysis is a promising technology for industrial organic waste to utilize their unique resource and energy properties for efficient conversion into valuable products. This study was the first time to characterize the co-pyrolysis of waste textiles with Ca-rich industrial sludge and Fe-rich industrial sludge on a laboratory-scale fixed bed. The properties, mechanisms, gas, oil and carbon production were investigated as a function of temperature and mixing type. Co-pyrolysis increased the total weight loss from 50.05 % to 69.81 % for Ca-rich industrial sludge mixed with 50 % waste textiles and from 49.13 % to 70.01 % for Fe-rich industrial sludge mixed with 50 % waste textiles. The activation energy of co-pyrolysis was approximately 50 % lower compared to the pyrolysis of waste textiles alone. The optimal reaction model for the different reaction stages for all samples was three diffusion (D3). Co-pyrolysis resulted in lower CO and CO2 emission temperatures of about 25–110 °C and produced more short-chain organic compounds (C < 10). Co-pyrolysis produced more aldehydes and ketones organics. Moreover, co-pyrolysis char exhibited an elevated level of fatty alkyl side chains and bridge branching, as well as higher degrees of aromatization and stability. This study offers valuable insights into the potential application of pyrolysis for the management of Ca/Fe-rich industrial sludge and waste textiles, thereby serving as a basis for future utilization endeavors.

AHP TOPSIS Analysis in Selecting Waste Processing Technology Based on Energy Justice

The amount of waste in Bantul Regency increased by 4.96% from 2020 to 2021, indicating that the capacity of final disposal sites (FDS) in Piyungan District, Bantul Regency, was decreasing. The peak occurred from 23 July 2023 to 5 September 2023, during which the Piyungan FDS could not provide waste disposal services. The high poverty rate in Bantul Regency forces the government to process waste into energy as a sustainable waste management effort. However, numerous criteria make it difficult to determine which technology is most suitable for this purpose. Energy justice criteria need to be considered when choosing technology and efforts to improve the welfare of Bantul Regency's residents. This research aimed to present an assessment of each alternative technology for processing waste into energy and decide one suitable alternative for sustainable waste management in Bantul Regency using a combination of AHP and TOPSIS methods based on energy justice. AHP was used to assess the level of importance of each criterion, while TOPSIS was used to determine the optimal alternative based on the criteria by considering costs and benefits. The findings showed that the preference value for three alternatives was 0.579, 0.414, and 0.341 for incineration, pyrolysis, and gasification, respectively. According to these preference value, incineration was identified as the foremost viable alternative technology for implementation in Bantul Regency. Gasification and pyrolysis ranked as the subsequent and third alternatives, respectively.

ROOT ZONE TECHNOLOGY FOR WASTE WATER TREATMENT

In India, the primary cause of surface and ground water pollution is the discharge of untreated sewage, according to a 2007 study by the Central Pollution Control Board. In India, there is a significant delay between the generation and treatment of household wastewater. India's insufficient treatment capacity is not the only issue; there are also sewage treatment plants that exist, but they are not being maintained or operated. Because of poor design, inadequate maintenance, unreliable electricity supplies, absentee staff, and incompetent management, the majority of government-owned sewage treatment plants remain closed for the most part of the year. Usually, the wastewater produced in these places evaporates or percolates into the soil. Uncollected waste builds up in urban areas, releasing pollutants that seep into surface and groundwater and creating unsanitary conditions. Furthermore, industrialists prefer not to treat the waste produced and instead to dump it untreated into rivers in the areas where these treatment plants are located because the cost of treatment is so high.The Root Zone Treatment System (RZTS), sometimes referred to as the reed bed system or the constructed wetland system, is a sealed filter bed that is planted with vegetation that can grow in wetlands and is made up of a sand, gravel, and soil system, sometimes with a cohesive element. The wastewater flows through the filter bed, where biodegradation of the wastewater occurs, after the coarse and floating material has been removed. Complex physical, chemical, and biological processes that are the outcome of the interaction of wastewater, wetland plants, filter bed material, and microorganisms define the functional mechanisms in the soil matrix that are in charge of the mineralization of biodegradable matter.

Statistical adaptive modeling for kitchen waste detection in complex scenes

Automatic detection of kitchen waste is of great significance, which provides support for its subsequent full quantitative consumption and harmless treatment. In addition, manual sorting of kitchen waste is inefficient and toxic waste is harmful to human health, making automatic detection of kitchen waste technology crucial. Automatic detection of kitchen waste in complex scenes faces the challenge of diversity of category outlines and uneven distribution. In this paper, we propose a detector based on statistical adaptive modeling(namely SA-Det) for the automatic detection of kitchen waste in complex scenes. Firstly, to solve the issue of diversity of category outlines, we propose a category statistics adaptive (CSA) module. The CSA module constructs dynamic thresholds for each instance to accurately assign positive and negative samples by fusing category statistics and instance shape information, thereby improving detection performance. Moreover, to solve the issue of uneven distribution, we propose a distribution adaptive (DA) module, which dynamically adjusts the loss weights by adaptively sensing the number of labels during training process. Extensive experiments on our constructed kitchen waste dataset (KWD) demonstrate that SA-Det consistently and significantly improves the performance of existing state-of-the-art methods (e.g., Rotated_RetinaNet (Lin et al., 2017) and RoI_Transformer (Ding et al., 2019)) by around 2% to 3.5%.