Solid Waste Minimization Research Articles

A review towards developing a hierarchical model for sustainable hospital solid waste management in rural areas of Zimbabwe.

Management of solid waste from rural hospitals is amongst problems affecting Zimbabwe due to diseases, population, and hospital increase. Solid waste from rural hospitals is receiving little attention translating to environmental health problems. Therefore, 101 secondary sources were used to write a paper aiming to proffer a hierarchical model to achieve sustainable solid waste management at rural hospitals. Rural hospitals' solid waste encompasses electronic waste, sharps, pharmaceutical, pathological, radioactive, chemical, infectious, and general waste. General solid waste from rural hospitals is between 77.35 and 79% whilst hazardous waste is between 21 and 22.65%. Solid waste increase add burden to nearly incapacitated rural hospitals. Rural hospital solid waste management processes include storage, transportation, treatment methods like autoclaving and chlorination, waste reduction alternatives, and disposal. Disposal strategies involve open pits, open burning, dumping, and incineration. Rural hospital solid waste management is guided by legislation, policies, guidelines, and conventions. Effectiveness of legal framework is limited by economic and socio-political problems. Rural hospital solid waste management remain inappropriate causing environmental health risks. Developed hierarchical model can narrow the route to attain sustainable management of rural hospitals' solid waste. Proposed hierarchical model consists of five-layered strategies and acted as a guide for identifying and ranking approaches to manage rural hospitals' solid waste. Additionally, Zimbabwean government, Environmental Management Agency and Ministry of Health is recommended to collaborate to provide sufficient resources to rural hospitals whilst enforcing legal framework. Integration of all hierarchical model's elements is essential whereas all-stakeholder involvement and solid waste minimisation approaches are significant at rural hospitals.

Modeling Solid Waste Minimization Performance at Source in Dar es Salaam City, Tanzania

Modeling Solid Waste Minimization Performance at Source in Dar es Salaam City, Tanzania

A Strategic model of municipal solid waste minimization based on decision-making and public participation

Municipal waste management is a public issue with health, environmental, economic and social implications at the home, local, national and international levels, so the scope of management of this category is very wide and variable, for such an organization there is no other way but strategic management. This qualitative-quantitative study was done with the help of smart pls2 software with the aim of designing a strategic model of minimization of solid waste management through maximum participation of citizens and stakeholders in decision making. It can be acknowledged that the optimal participation of all internal and external stakeholder organizations and citizens in the policy and executive systems of waste management is very important in order to achieve the goal of quality improvement. In this way, it has been tried to establish a two-way relationship between the citizens and the private sector with the public sector through the participation of all sectors. So, the final consumers of waste, can interact with the municipalities through councillors and community center and provide to reduce waste mechanisms to receive citizens' opinions and attract citizens' participation. In fact, cities and municipalities should not try to do everything alone.

Tailor-made biochar-based nanocomposite for enhancing aqueous phase antibiotic removal

In the present study, an innovative biochar-based metal(loid) oxide nano-matrix doped hybrid nanocomposite (nMOC) from kitchen waste-derived biochar (KWB) and ZnO/SiO2 was used for aqueous phase tetracycline removal. It involved a three-stage process, entailing thermal conversion of biomass to KWB, synthesis of ZnO/SiO2 nano-matrix, and nMOC fabrication via ball-milling. Advanced characterizations were employed to determine surface chemistry, surface morphology, surface area, and elemental composition, exhibited thermostable, mesoporous, heterogeneous, ZnO/SiO2-doped matrix with rich active surface-functional groups. The nMOC showed excellent performance (95.27 ± 0.304 %) for TC removal through batch mode adsorption study for 7.0 mg L−1 aqueous TC solution at ambient temperature. The sorption data were statistically evaluated through linear and non-linear isotherms, kinetics, and thermodynamics modelling incorporating error function analysis, suggested spontaneous, exothermic, and multilayer chemisorption with complex diffusional adsorption phenomenon. The adsorption mechanisms were governed by, electrostatic interaction, H-bonding, π-π stacking interactions, and pore-filling. Regeneration study demonstrated the maximum efficiency using EDTA (81.39 ± 1.234 %). Experiments on interference by co-existing ions suggested lesser impact by monovalent anions (NO3−) than divalent anions (SO42−), and monovalent cations (NH4+). The nMOC showed enhanced TC adsorption and excellent reusability along with dual benefits of minimization of solid kitchen waste and very effective antibiotic removal from (waste)water.

Solid waste minimization in Sweden: management proposals for Brazilian municipalities

Resumo Para que a reciclagem aconteça, são necessárias normas, participação social e infraestrutura adequada para a coleta do material descartado. As estruturas e as normas internacionais e nacionais que norteiam o gerenciamento dos resíduos sólidos na Suécia favorecem a redução do volume descartado. Nesse contexto, este artigo objetiva examinar os arranjos institucionais dos serviços de manejo dos resíduos sólidos da Região Metropolitana de Estocolmo e seus efeitos sobre a diminuição do volume encaminhado para destinação final. A metodologia utilizada tem natureza exploratória, do tipo descritiva, com análise qualitativa. Os arranjos institucionais aplicados na Suécia vêm contribuindo para o alcance de objetivos nacionais e internacionais propostos para o país e podem inspirar o aperfeiçoamento do gerenciamento desses serviços no Brasil.

A Conceptual Framework Analysing Malaysian University Students’ Solid Waste Minimisation Behaviour: An Integrated Model

The magnitude of the global waste crisis highlights the urgent need for its mitigation. In Malaysia, consumer solid waste generation significantly contributes to the proliferation of municipal solid waste. University students, as a subset of the youth demographic, are considered the future gatekeepers of environmental preservation and sustainability. The present study proposes a conceptual framework that integrates the Transtheoretical Model (TTM) and Identity Theory to analyse solid waste minimisation behaviour among university students in Malaysia. The framework postulates that student behaviour varies across five TTM stages. The primary aim is to investigate the significance of pro-environmental self-identity (PESI) as an underlying motivation at various stages of the TTM. Besides behavioural adoption, the proposed framework emphasises the maintenance aspect of the behaviour, along with possible relapse effect. The knowledge generated from this study could be utilised by both policymakers and intervention planners to create student segmentation for a more streamlined behavioural change and Campaign, Education, Public Awareness (CEPA) effort. The present study supports the Sustainable Development Goal (SDG) 12 (Sustainable Consumption and Production) target and the green growth goals outlined in the Twelfth Malaysian Plan 2021–2025.

Real time monitoring of solid waste with customized hardware and Internet of Things

According to the United Nations' Sustainable Development Goals (SDGs), waste collection and management are essential public services for every community and are also necessary for the protection of public health and the environment. The minimization of solid waste is possible with the integration of advanced technologies like the Internet of Things (IoT), and the cloud. In this study, WPAN and cloud-assisted architecture are proposed and implemented to real-time monitor solid waste from any remote location through Xbee communication and the internet. The customized hardware is implemented in real-time by embedding it in the bins. The customized sensor node and coordinator node which are connected with the cloud server visualize the sensor data and also enable real-time monitoring of the bins. LabVIEW data logger receives the bin status and represents the status of the bin in digital form. The sensor data is visualized on the cloud server via WPAN and internet connectivity.

A Comparative Study of the California Bearing Ratio Value of Subgrade Made by Stone Dust and Natural Sand with Coarse Aggregate

Resources of engineering materials (sand) used for construction activities are limited, so some other materials should be introduced by changing the sand. Stone dust produced from Stone Crushing Zone appears as a problem for effective disposal. Stone dust can be replaced by sand which is used as a fine aggregate in construction work. In this study, the main concern is to find an alternative to sand. Replacement of normal sand by stone dust will work both solid waste minimization and sand recovery. Stone dust is one of the alternatives to sand which can meet the demand of fine aggregate. In the engineering practice, the properties of existing sub-grades are required for the construction of the earth, thereby improving density and strength of the subgrade. A series of California Bearing Ratio (CBR) tests have been conducted for determination of soaked and un-soaked CBR by using the stone dust as a fine aggregate blended with 10 mm and 20 mm size Coarse Aggregates (CA). A detailed comparison is made for the findings of the CBR tests conducted on samples prepared using natural sand (as a fine aggregate) blended with 10 mm and 20 mm size coarse aggregates.

Recent Advances in Synthesis and Degradation of Lignin and Lignin Nanoparticles and Their Emerging Applications in Nanotechnology.

Lignin is an important commercially produced polymeric material. It is used extensively in both industrial and agricultural activities. Recently, it has drawn much attention from the scientific community. It is abundantly present in nature and has significant application in the production of biodegradable materials. Its wide usage includes drug delivery, polymers and several forms of emerging lignin nanoparticles. The synthesis of lignin nanoparticles is carried out in a controlled manner. The traditional manufacturing techniques are costly and often toxic and hazardous to the environment. This review article highlights simple, safe, climate-friendly and ecological approaches to the synthesis of lignin nanoparticles. The changeable, complex structure and recalcitrant nature of lignin makes it challenging to degrade. Researchers have discovered a small number of microorganisms that have developed enzymatic and non-enzymatic metabolic pathways to use lignin as a carbon source. These microbes show promising potential for the biodegradation of lignin. The degradation pathways of these microbes are also described, which makes the study of biological synthesis much easier. However, surface modification of lignin nanoparticles is something that is yet to be explored. This review elucidates the recent advances in the biodegradation of lignin in the ecological system. It includes the current approaches, methods for modification, new applications and research for the synthesis of lignin and lignin nanoparticles. Additionally, the intricacy of lignin’s structure, along with its chemical nature, is well-described. This article will help increase the understanding of the utilization of lignin as an economical and alternative-resource material. It will also aid in the minimization of solid waste arising from lignin.

МОДЕЛІ ВІДПОВІДАЛЬНОГО СПОЖИВАННЯ У РОЗБУДОВІ ГЛОБАЛЬНОЇ ЗЕЛЕНОЇ ЕКОСИСТЕМИ

The article emphasizes the steady increase in the scale of global consumption of goods and services due to the rapid increase in the value of household wealth in all regions of the world. Accordingly, a contradiction between the constantly growing needs of global consumers and the inability of available resources to satisfy them has been arising. The author believes that the mentioned contradiction can be effectively resolved solely based on the greening of public consumption and the mass introduction of models of responsible consumption into consumer relations. The article describes the main existing models of responsible consumption. First, the author notes the increasing orientation of the global consumer towards the joint (collective) consumption of goods, the formation and development of the "sharing economy". As another model of responsible consumption, the practices of minimization of solid household waste by consumers and their transition to sorting garbage and separate methods of its disposal have been analyzed. The special importance of the development of such a model of responsible consumption as an increasing orientation of economic subjects towards the consumption of ecologically clean goods and healthy food has been proven. An assessment of such trends has been made in the article. In the comprehensive description of models of responsible consumption, the author focuses on such a direction as the refusal of consumers from single-use packaging of purchased goods in favor of its economical options, as well as reusable and ecological packaging. Accordingly, the author also analyzes the trend of the transition of world production to ecological packaging, with the introduction of the system of extended producer responsibility. The author evaluates the trend of consumption of durable goods as another effective model of responsible consumption. The author believes that extended responsibility of manufacturers implies their responsibility not only for the design, production and market sale of manufactured goods, but also for the safe handling of their packaging waste throughout the entire product life cycle.

Pulp and paper characterization by means of artificial neural networks for effluent solid waste minimization—A case study

Paper mills are among the most polluting industries, responsible for many organic and inorganic compounds emissions. The fibres electro-kinetic features strongly affect the ability to retain fillers since the fillers–fibres interactions are charge induced. The control and the prediction of these parameters would represent a precious aid for process management, allowing the fillers retention enhancement, a lower environmental impact and the paper sheet properties streamlining. The work presented deals with the implementation and training of four artificial neural networks (ANNs) for the prediction of the main electrochemical and physical features of cellulose pulp and paper. First, two ANNs predict the electrochemical parameters. Following, they were applied to predict the paper sheet properties and fillers retention. The neural models implemented showed outstanding prediction performance, with R2 in the order of 0.999 and a low mean error. The results demonstrate how Artificial Neural Networks may be a valuable instrument for paper mill pollutant reduction. However, they suggest a more inclusive investigation for a better fibres behaviour representation.

Sustainable Campus Through Solid Waste Minimization Strategies (Case study: Universitas Agung Podomoro in Indonesia)

A large amount of solid waste (SW) generation becomes inevitable for campus due to its population and variety of activities. Therefore, it is a challenge to develop and implement SW minimization plan to encourage sustainable campus practices. The aim of this study was to develop sustainable strategies to support this plan for Universitas Agung Podomoro (UAP) included evaluating the SW management condition by monitoring the SW generation and surveying the perception and willingness to participate of campus society. The results showed that the SW generation was 52.63 kg/day or 0.08 kg/person/day. The composition consisted of 32.29% biodegradable and 67.71% non-biodegradable. The recycling potential was 61.01% consisted of 22.28% composting and 38.73% recycling. The social survey showed that respondents had positive perceptions about SW minimization. The complete evaluation resulted in the development of strategies to decrease the SW generation rate, increase the recyclable material rate, and increase the participation of campus society.

Resíduos sólidos no Parque Nacional da Chapada dos Veadeiros

Meios de hospedagem são os maiores geradores de resíduos sólidos do setor turístico. No contexto da instituição da Política Nacional de Resíduos Sólidos e uma série de orientações sobre gestão sustentável de empreendimentos turísticos, elaboradas pelos órgãos públicos brasileiros, torna-se relevante avaliar as práticas dos meios de hospedagem nesse sentido. Este estudo analisa a gestão de resíduos sólidos nas pousadas e hostels de Alto Paraíso (GO), cidade com a maior capacidade de alojamento mais próxima da entrada do Parque Nacional da Chapada dos Veadeiros. Trata-se de um estudo de caso, com coleta de dados por meio de entrevistas em dez meios de hospedagem e com um representante da associação de reciclagem local. Os resultados indicam uma fraca conscientização dos clientes, forte dependência de decisões das autoridades locais, pouca vontade de cooperar e desconhecimento de técnicas de minimização de resíduos sólidos.

Implementation green industry standard at textile industry and textile product

At present industrialists must begin to shift from the industry as usual to an environmental industry or what is now known as a green industry. An important issue in the principle of green industry that needs to be understood and implemented is industries in their production processes implement sustainable efficiency and effectiveness in resources. The green industry is not only oriented towards improving the economic sector but also concerned with environmental sustainability. So the negative impact on the environment and the use of natural resources providers of industrial supports, does not result in a decrease in the carrying capacity and capacity of the environment. Therefore to realize the textile industry and textile products that are environmentally friendly, the necessity to develop industrial performance by integrating the principles of the green industry into the production process. This paper will explain the implementation of green industry characteristics that can be adapted into each stage of the production process in the textile industry and textile products, especially the batik industry. The characteristics of the green industry include the efficiency of the use of input materials, namely raw materials and auxiliary materials and the use of alternative materials that are more environmentally friendly, low energy and water intensity, minimization of waste both liquid and solid waste and reducing emissions due to the use of low-carbon technology. Each characteristic is equipped with criteria in the green industry standard (GIS) that can be used by textile and textile products industrialists, especially the batik industry in implementing the principles of the green industry.

Solid Waste Generated by Amazon and Tapajós River Vessels: An Environmental Education Activity

Given the lack of research on solid waste generated by vessels and often incorrectly discarded, it became clear the need for a new methodological approach focusing on the knowledge of this theme. Thus this study was conducted focusing on the process of awareness of users of a vessel that made the route that traveled the Amazon River and Tapajós, using an environmental awareness activity, with results and immediate observations. From this, the waste was quantified before and after the interventions, which occurred from the clarification of the environment, solid waste generation, natural resources, water, among others. The research took place aboard a vessel that connects Manaus-AM to Alenquer-PA, evaluating the before and after the intervention. Given this, it is verified that the evaluation process achieved positive results in the minimization of solid waste generated, ensuring that the study has immediate effect, but the intervention measures need time for consolidation, given the responsibility of environmental education, which needs different approaches, under different eyes and with depth of knowledge, even if it requires a long-term process. Therefore, the importance of this type of activity is verified, aiming at the correct destination of the solid waste generated, in any circumstance, mainly in vessels, in different rivers, considering the condition of this natural resource. In addition, user awareness and education through environmental education is mandatory to better understand the impacts caused by different changes over time and needs to be an effective tool to ensure the success of habit transformation processes and quality improvement of life.

ENHANCING THE POTENTIAL OF RECYCLABLES WASTE COLLECTION THROUGH WASTE BANK PROGRAMME: EXPERIENCE FROM HEI IN MALAYSIA

A voluntary approach for recycling programme can be enhanced by the establishment of waste bank in institutions of higher education. Hence, a waste bank programme was implemented in a “close loop” system at the Faculty of Environmental Studies, Universiti Putra Malaysia (FPAS, UPM). This aims to promote collection of recyclable materials and raise awareness among UPM students on the importance of recycling. Throughout the five (5) phases of operation, about 500 students were registered as waste bank members with the amount of total collected recyclables reaching 14,817.46 kg. The direct measurement method was applied in the waste bank operation procedure to weigh the recyclable materials received twice a week. The most frequent type of recyclable material collected was paper, including black/white paper, newspaper, and mix paper. The waste bank programme has enhanced the potential of solid waste minimisation by shifting the amount of waste disposed at the landfill site. Moreover, it enables recyclable materials to be seen as valuable resources as monetary rewards were given to encourage recycling practices among students based on the total weight for each collection of recyclable materials. Therefore, the implementation of the waste bank programme in Higher Education Institutions (HEI) in Malaysia creates an opportunity to be a medium of a sustainable solid waste minimisation system in promoting sustainable green campuses at the university.

ENHANCING THE POTENTIAL OF RECYCLABLES WASTE COLLECTION THROUGH WASTE BANK PROGRAMME: EXPERIENCE FROM HEI IN MALAYSIA

A voluntary approach for recycling programme can be enhanced by the establishment of waste bank in institutions of higher education. Hence, a waste bank programme was implemented in a “close loop” system at the Faculty of Environmental Studies, Universiti Putra Malaysia (FPAS, UPM). This aims to promote collection of recyclable materials and raise awareness among UPM students on the importance of recycling. Throughout the five (5) phases of operation, about 500 students were registered as waste bank members with the amount of total collected recyclables reaching 14,817.46 kg. The direct measurement method was applied in the waste bank operation procedure to weigh the recyclable materials received twice a week. The most frequent type of recyclable material collected was paper, including black/white paper, newspaper, and mix paper. The waste bank programme has enhanced the potential of solid waste minimisation by shifting the amount of waste disposed at the landfill site. Moreover, it enables recyclable materials to be seen as valuable resources as monetary rewards were given to encourage recycling practices among students based on the total weight for each collection of recyclable materials. Therefore, the implementation of the waste bank programme in Higher Education Institutions (HEI) in Malaysia creates an opportunity to be a medium of a sustainable solid waste minimisation system in promoting sustainable green campuses at the university.

Minimization of household hazardous solid waste (HHSW) with 4R concepts (reduce, reuse, recycle and recovery) in Padang City, Indonesia

Improper management of hazardous waste originating from household activities will potentially pose a threat to health and the environment. Management of hazardous waste includes minimization activities and hazardous waste treatment. This study aims to analyze the existing conditions and potential minimization of Household Hazardous Solid Waste (HHSW) with the 4R concept, namely Reduce, Reuse, Recycle and Recovery in Padang City. HHSW minimization data was obtained through the analysis of questionnaire data distributed to several HHSW generation sources in Padang City, while the minimization potential was obtained from the existing literature review. The minimization of the existing HHSW was 17.4% (2,067 kg/day) from the total HHSW generation in Padang City. This minimization activity consisted of 11.6% reduce activities, 2.2% reuse activities and 3.6% recycle activities. From the calculation and literature study, the potential of minimizing HHSW was 51.2% (6,081 kg/day) which consists of 11.6% reduce potential in the form of large volumes of HHSW packaging purchases, 18.7% reuse potential through the return of product packaging to producers in the Environmental Producer Responsibility (EPR) program, 13.2% recycle potential in the form of oil can recycling, bulbs and cartridges, and 7.7% recovery potential by recovering metal content in batteries and car battery.

ЕКОЛОГІЯ ТА СЕРЕДОВИЩЕЗНАВСТВО ЯК НАУКИ І СПЕЦІАЛЬНОСТІ

The tendencies in the development of the scientific-methodological and educational-methodical sphere related to the problems of deepening ecological knowledge, the ecologization of the spheres of productive and non-productive activities and education in particular, are analyzed. The world tendencies and main features of the current situation in environmental education in Ukraine are outlined. The necessity of entering the world standards of studying and assessing the state of the natural environment and the human environment is emphasized. The scheme of methodological structuring and improvement of the new in Ukraine, but well-established in European countries, the field of research and practical knowledge - environmental science – is presented.
 The environmental science is concerned with the study of all levels of the natural environment, from the cosmic to the intracellular, as well as all levels of the anthropic environment, from the technogenic to the productive, from the socio-cultural to the spiritual-aesthetic. A unique phenomenon of nature is the recognition of multi-level biotic – intra-ecosystem and intra-organismal environments.
 The subject matter of environmental science is constituted by the scientific foundations of the balanced coexistence of the medium-forming animate and inanimate natural systems and the human community, the methods of rational use of real-energy natural resources for the benefit of mankind without the destruction of the environment.
 The environmental science aims at the development and promotion of reasonable principles of coexistence of natural and social medium-forming systems in the environment in order to preserve the possibility of satisfying present and future generations of their material and non-material needs.
 As a system of knowledge, the science of the environment is filled with new information about the evolutionary unity of the material inanimate and living world, the role of science and spirituality in its understanding and preservation. Based on modern scientific and philosophical principles, the perception and importance of the biotic systems, biodiversity and eco-means of all levels is grounded. 
 The environmental science studies the history of the emergence of the human population, its transformation into planetary geological force. Various spheres of human activity are considered, such as urbanization, social hygiene and health, agricultural production, food supply and threats typical of these activities. An inseparable part of education in environmental science is the knowledge of physical real-energy resources and the values of stability of inanimate medium-forming systems. Here, it is necessary to obtain geological knowledge, to study atmospheric phenomena, climate, water resources, natural disasters, as well as ways to control and protect them from pollution, destabilization or depletion.
 The current section of environmental science deals with the problems of civilization development and the latest achievements in such areas as renewable and safe energy, minimization and neutralization of solid and toxic waste, sustainable urbanization, non-destructive for environment and resources economics, balanced policies and legislation. Nonetheless important is active and optimistic promotion of the necessity to introduce principles of sustainable (eco-safety) development in all spheres of human activity, the formation of the mindset on the inevitability of transition to an economical way of life of an individual and civilization, the need to take an active civil position in society to preserve the environment.
 The list of priority disciplines for obtaining an education in the specialty of Environmental Protection Technologies is given. It is emphasized that the differentiation of the spheres of research and the study of general ecology and environmental science will allow us to streamline and improve the quality and pace of the ecologization of public consciousness. The implementation of above mentioned ideas will improve the results of environmental and nature protection activities, and will also contribute to the ongoing ecological research.

Adsorption kinetics and modeling of H2S by treated waste oil fly ash

ABSTRACTWaste oil fly ash (OFA) collected from disposal of power generation plants was treated by physicochemical activation technique to improve the surface properties of OFA. This synthesized material was further used for potential hydrogen sulfide (H2S) adsorption from synthetic natural gas. The raw OFA was basically modified with a mixture of acids (20% nitric acid [HNO3] and 80% phosphoric acid [H3PO4]), and it was further treated with 2 M potassium hydroxide (KOH) to enhance the surface affinity as well as surface area of synthesized activated carbon. Correspondingly, it enhanced the adsorption of H2S. Crystallinity, surface morphology, and pore volume distribution of prepared activated carbon were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analyses. Fourier transform infrared (FTIR) study was also performed to identify the functional groups during different synthesis stages of modified activated carbon. The Langmuir, Freundlich, Sips, and dual-site Langmuir (DSL) models were used to study the kinetic and breakthrough behavior of H2S adsorption over alkali-modified activated carbon. Modeling results of isotherms indicated that OFA has dual sites with high and low affinity for H2S adsorption. The Clark model, Thomas model, and Yoon-Nelson model were used to examine the effects of flow rate and inlet concentration on the adsorption of H2S. Maximum uptake capacity of 8.5 mg/g was achieved at 100 ppm inlet concentration and flow rate of 0.2 L/min.Implications: Utilization of worthless oil fly ash from power plant is important not only for cleaning the environment but also for solid waste minimization. This research scope is to eradicate one pollutant by using another pollutant (waste ash) as a raw material. Chemical functionalization of synthesized activated carbon from oil fly ash would lead to attachment of functional groups of basic nature to attract the acidic H2S. Such type of treatment can enhance the uptake capacity of sorbent several times.