Thermal Incineration Research Articles

EFFECTIVE MANAGEMENT OF HOSPITAL AND MEDICAL WASTE IN RURAL AREAS OF PAKISTAN: A CASE STUDY

The proper management and safe disposal of increasing amount of solid wastes has been recognized as a global problem of the recent age. Toxic and hazardous constituents present in the solid wastes, make this problem even more critical and challenging. Exposure of such solid waste, when not managed properly significantly effects the local environment and public health. For example, bio-hazardous wastes generated from hospital and other clinical settings possess heterogeneous constituents with potentially infectious properties imposing a significant threat to the public health as well as the natural environment. This becomes more curious in case of epidemic diseases treatment and cure procedures. There are several techniques used to treat the infectious wastes, however, adoption of either technique depends upon the type of material and available resources. Thermal treatment or incineration has been found as one of the common and efficient methods for toxic waste management in which waste materials are ignited and burnt under controlled conditions destroying the toxic constitutes of the hazardous materials. The present study has been taken up in order to study the toxic waste management with emphasis on hospital waste. The case of basic health unit has been taken in order to assess and quantify toxic waste potential and its management. The study has also come up with a proposed design of small-scale fixed bed incinerator for hospital waste.

Atmospheric chemical composition of bulk deposition at two geographically distinct locations in Sri Lanka.

This study presented the research work carried out for the investigation of chemical composition of bulk precipitation in two geographically and economically distinct areas, namely Gampaha and Kandy Districts. This study was conducted from 2013 to 2014 at three sampling stations in each District. The bulk precipitation was analyzed for pH, conductivity, Na+, NH4+, K+, Mg2+, Ca2+, F-, Cl-, NO3-, SO42-, Pb, Cu, Mn, Al, Zn and Fe for a total of 375 samples. Only 8% events of acidic precipitation were recorded in Gampaha District when compared with 3% in Kandy District. The volume weighted average concentrations of the major ionic species present in precipitation samples were in the order of Na+ > Ca2+ > Cl- > NH4+ > SO42- > Mg2+ > NO3- > K+ > F- in the Gampaha stations, while the order was NH4+ > Ca2+ > Na+ > Cl- > SO42- > Mg2+ > NO3- > K+ > F- in Kandy District. Neutralization of acidity of precipitation is much more related to CaCO3 than NH3, and high content of Ca2+ ions present in both Districts strongly supports this fact. When considering marine contribution, SO42-/Na+, Ca2+/Na+ and Mg2+/Na+ ratios are higher than the reference value suggesting contribution of sources other than marine. Depositions of both Districts show that the concentration of Al is the highest while that of Mn is the lowest. Principal component analysis suggests that influencing human activities on chemical composition of rain water depends on thermal power plant, oil refinery, heavy traffic and waste incineration in the study area.

Investigating the activation of hydrochar from sewage sludge for the removal of terbuthylazine from aqueous solutions

Hydrothermal carbonization offers the opportunity to reduce the issues related to the management of sewage sludge, enhancing dewaterability and avoiding thermal treatment prior landfill disposal or incineration, as water acts as a subcritical medium which catalyzes the process. The hydrochar obtained can find sustainable application as fuel, sorbent and soil amendment. Here, the effects of activation temperature (550–750 °C), time (1–4 h) and impregnation ratio potassium hydroxide: hydrochar (1–3), as well as their interactions, were investigated by Response Surface Methodology. The carbonaceous sorbent was then applied for the removal of terbuthylazine from aqueous solutions. Solid yields up to 32.31% were obtained, with corresponding ash content ranging from 13.05 to 35.06%. The combined effect of time and temperature significantly affects the ash content. An increase of impregnation ratio or temperature leads to low yields but high terbuthylazine adsorption, while the effect of the activation time on the pollutant removal is negligible. Up to 63.87% of the herbicide was adsorbed by the activated material, at terbuthylazine concentration of 2.5 mg L−1. The developed sorbent well fits the circular economy approach, offering a promising potential for sewage sludge management, as well as for water remediation.

Effect of Heat-Treatment Remediation on the Mechanical Behavior of Oil-Contaminated Soil

The heat treatment of oil-contaminated sites is widely carried out for the purposes of remediation. However, heat treatment changes the physical and chemical properties of soil. Before the soil can be reused as a construction material in civil engineering, such as in backfill or road base materials, the changes to its physical properties must be understood. Therefore, this study investigates the changes in the physical and chemical properties of oil-contaminated soil after heat treatment. In this investigation, experimental samples of soil with added oil from a refinery plant are used to investigate the removal rate of total petroleum hydrocarbons (TPHs) by thermal desorption and incineration. The physical properties of the soil, including water permeability and mechanical properties, are compared before and after heat treatment. The results of this study are as follows. (1) Particle size analysis reveals that heat treatment makes soil particles finer. (2) In the burning reduction test, heat treatment at 900 °C removes more than 90% of THP. (3) In the direct shear test, the friction angle (ϕ) increases with the removal rate. (4) In the hydraulic test, as the removal rate increases, the permeability coefficient increases after heat treatment.

Valorisation of discarded nonwoven polypropylene as potential matrix-phase for thermoplastic-lignocellulose hybrid material engineered for building applications

Textiles are a global fast-growing highly-abundant complex waste stream constituted by heterogeneous mixtures of polymers, which at the end-of-life routinely are subject to thermal destruction, incineration, or landfill. Alternatively, this study targets the cascading use of these resources within a circular green manufacturing scheme, examining for the first time the utilization of recycled nonwoven textile Polypropylene (PPt), selected from single-use disposable technical-grade garments in the function of matrix-phase; for the development of non-toxic thermoplastic-lignocellulose hybrid sheet materials engineered for building applications. For this purpose two sources of recycled Polypropylene –textile and food packaging– were selected for the comparative analysis between fibrillated and particulate matrices; and wood fibres sourced from furniture manufacturing residual waste were selected as the lignocellulosic disperse-phase, formulated in the ratio of 40/60 wt%, respectively. The hybrid compounds were mechanically micronized, homogenized, and no coupling agent or additives were incorporated. The overall experimental results indicated PPt presented competitive advantages over the particulate polypropylene due to distinctive morphological, microstructural, crystallinity, and chemical variances; which improved the Filler-Matrix interfacial behaviour, increased the hydrophobicity of the blend, as well as facilitated the thermal-processing of the hybrid prototypes during isothermal hot-compression. Consequently, the end-product exhibited peak performance for flexural strength, moisture resistance, and fire-retardant properties, thus, suggesting that disposable technical-grade PP textiles introduce a viable alternative solution for the advancement of multifunctional sustainable building materials manufactured entirely from heterogeneous complex waste mixtures.

PRODUCTION OF LIME WITH HIGH REACTIVITY IN A FLUIDIZED BED APPARATUS OF AN INERT MATERIAL

In dry desulfurization, for example, of gaseous combustion products of thermal power plants and incineration plants, calcium oxide CaO, as a product of firing of natural carbonate rocks, mainly limestones (CaCO3), is widely used. Firing technology, depending on the limestone heat treatment regimes, form a product with certain physicochemical properties: porosity, specific surface, shrinkage value, chemical activity. The influence of heat treatment conditions on the properties of the product obtained is studied. The possibility of fast low temperature heat treatment of finely dispersed limestone in a fluidized bed of an inert material to produce CaO of the required quality is shown. Research facility, technique for carrying out experiments and processing experimental data are described. As a result of the research, the degree of calcination of 80 % of fine limestone in a device with fluidized bed of inert material was achieved and the residence time of the particles in the inert layer was determined. Bibl. 10, Fig. 2, Tab. 1.

A systematic approach for selecting an optimal strategy for controlling VOCs emissions in a petrochemical wastewater treatment plant

This study assessed the fate of benzene, toluene, and styrene in a full-scale petrochemical wastewater treatment plant (WWTP) with respect to the selection of an efficient and cost-effective control strategy. To prepare input parameters for TOXCHEM, wastewater samples were collected from the inlet of treatment units. Subsequently, the resultant emission rates were applied in AERMOD to study the dispersion patterns of the target volatile organic compounds (VOCs). Based on the TOXCHEM results, the overall emission of benzene, toluene, and styrene was 123,935 g/day, of which 73.4, 13.3, and 13.4% were benzene, toluene, and styrene, respectively. The results indicated that up to 99.5% of the target VOCs were removed from wastewater by volatilization and biodegradation mechanisms. Also, more than 85% of the VOCs emission occurred from the primary treatment units (American Petroleum Institute oil separator, equalization basin, and dissolved air flotation system). In some cases, the concentration distribution profiles resulting from AERMOD showed higher values than EPA reference concentrations (RfC) around the study area. The most affected area was near the WWTP with maximum 1-h concentrations of 8166, 1267, and 1228 μg/m3 of benzene, toluene, and styrene, respectively. Based on the modeling results, the most applicable and available methods for separating and ultimately disposing of VOCs were investigated and compared with the aim of reducing emission rates to meet ambient air quality standards. The results revealed that steam stripping is the most efficient and cost-effective VOCs control strategy in the studied plant. Moreover, thermal incineration was marked as the first choice for ultimate disposal of the contaminated air streams.

Study on potency of municipal solid waste conversion into renewable energy by thermal incineration and bioconversion: case study of Medan city

Municipal solid waste (MSW) in Medan City is facing problems either with the quantity and management of MSW. Local authority only dumped approximately 73.9% MSW in the landfill over the years. Spontaneous phenomena of methane formation in dumping site indicates the potency of MSW conversion into energy by biochemical conversion. On the contrary, the presence of plastics, woods, papers, etc. in the MSW show the potency of MSW to be treated by thermal conversion. Both thermal incineration and anaerobic digestion may convert MSW Medan City into energy. This study evaluates potency of MSW conversion into renewable energy using proximate and ultimate analysis. Overall, MSW of Medan City has the opportunities to be converted into energy by both thermal and biochemical conversion with a special requirement such as pre-dry the MSW prior incineration process and degrade organic MSW in a bioreactor.

A review of Waste Tyre Rubber as an Alternative Concrete Consituent Material

The current global waste tyre generation far exceeds its consumption in terms of recycling and re-use. The traditional recycling and re-use methods like thermal incineration have proven ineffective, costly and in some cases environmentally unsustainable. Particularly, in developing countries where some of the sophisticated techniques required to process tyres to allow them to be utilised are either too costly or have not yet been developed. The situation has resulted in accumulation of large waste tyre stockpiles that pose health and safety risks. To combat the problem, the use of waste tyre rubber in concrete construction has been proposed. Several studies have been conducted to assess the effects of the inclusion of waste tyre rubber in its different forms (fibres, particles), for concrete production and the results are promising. Although there are some apparent demerits to the inclusion of tyre rubber in concrete, the potential benefits seem to overshadow the negatives. This paper reviews published research on the scientific and technical viability of using waste tyre rubber in concrete production. It discusses the production and properties of waste tyre particles. It highlights advances made with regards to the incorporation of tyre rubber material in concrete, focusing on the engineering properties of the tyre rubber modified concrete. In conclusion, recommendations for future research and possible application for the material will be discussed.

Evaluation of Thermal Hydrolysis and Incineration of Sludge for Energy Recovery at an Advanced Water Reclamation Facility

Evaluation of Thermal Hydrolysis and Incineration of Sludge for Energy Recovery at an Advanced Water Reclamation Facility

Thermal Hydrolysis and Incineration of Sludge: Evaluating Their Role in Optimizing Energy Profiles at Advanced BNR Facilities

Thermal Hydrolysis and Incineration of Sludge: Evaluating Their Role in Optimizing Energy Profiles at Advanced BNR Facilities

Thermal disposal of waste containing nanomaterials: first investigations on a methodology for risk management

Considering the wide use and production of NMs since last two decades, these trendy nanomaterials (NMs) are expected to end up in thermal disposal and waste incineration plants (WIP). It seems relevant to assess the risks related to the thermal disposal and incineration of waste containing NMs (WCNMs). The objective of this work is to present a first approach to develop a preliminary methodology for risk management in order (1) to give insights on nanosafety of exposed operators and on potential environmental risks related to the incineration and thermal disposal of WCNMs, and (2) to eventually support decision-makers and incineration plant managers. Therefore, the main challenge is to find (a) key parameter(s) which would govern the decision related to risk management of NMs thermal disposal. On the one hand, we focused on the relevant literature studies about experimental works on incineration of NMs. On the other hand, we conducted an introductory discussion with a group of experts. The review of this literature highlights that the nano-object’s nanostructure destruction appears as a relevant indicator of the risks related to the NMs incineration. As a consequence, we defined a “temperature of nanostructure destruction” (TND) which would be the temperature from which the nanostructure will be destroyed. This parameter has been assumed to be a consistent indicator to develop a preliminary methodology. If the combustion chamber temperature is higher than the TND of the NM (or if they are close to each other), then the nanostructure will be destroyed and no risks related to NMs remain. If the TND of the NMs is higher than the combustion chamber temperature, then the nanostructure will not be destroyed and risks related to NMs have to be considered. As a result, five groups of NMs have been identified. WCNMs including carbonic NMs appear to be in good position to be destroyed safely in WIP. On the other hand, based on this criterion, there would be no available thermal disposal plants to safely manage WCNMs including CeO2 and ZrO2. Finally, a decision tree has been designed. TND is used as criteria to assess if a waste can be managed safely or not by a specific thermal disposal and which safety measures have to be taken.

Anaerobic digestion for the stabilization of the organic fraction of municipal solid waste: A review

Anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) has gained great interest in the last few decades. Presently, among the various municipal solid waste management (MSWM) techniques, such as sanitary land-filling, aerobic or anaerobic composting, and thermal incineration, AD is being considered as the most techno-economically viable method owing to its many advantages. AD not only serves to efficiently manage and treat an enormous quantity of OFMSW but also acts as a convenient source of non-conventional energy. The methane generated via AD of OFMSW serves as a potent substitute for fossil-based fuels. Given the current global energy crisis, this technology may be a welcome boost to the global energy demand. In this review an attempt has been made to provide a comprehensive understanding of: (i) the origin and scope of AD of OFMSW; (ii) the potential of AD for OFMSW stabilization; (iii) various pilot and bench-scale studies conducted hitherto; (iv) the process design aspects of AD of OFMSW; (v) the potential of energy recovery from AD of OFMSW; and (vi) the past experiences of AD of OFMSW. This review also delves into the critical issues that govern the process of AD in stabilizing OFMSW. In addition, the compatibility of AD for MSWM in the Indian scenario compared to other classical methodologies, such as landfilling, composting, thermal incineration, and pyrolysis or gasification, is highlighted. An overview of the overall future prospect of AD of OFMSW is discussed.

Design and Optimization of Dish for Solar Thermal Incineration

Waste disposal in remote areas is a hurdle due to lack of active dumping space. Besides, improper dumping of waste on empty land can have a detrimental impact on the environment. Incineration of waste using thermal incineration (using a solar concentrator) can be utilized for mobile incineration devices to dispose of hazardous waste effectively with a limited space. The design and mobility of the solar dish for this purpose is one of the most important considerations. The modeling of the solar dish was performed on SOLIDWORKS® with APEX® for optical simulation. The simulation results showed a linear variation of flux coating to enable a more comprehensive cost benefit analysis for the design. The simulation was also used to check whether the required flux at focus (to achieve ignition) was achieved. Further work is required to validate the results.

A Numerical Study for the Thermal Incineration Characteristics of CF4

A Numerical Study for the Thermal Incineration Characteristics of CF4

SORPTION OF ZINC USING MICROWAVE INCINERATED SUGARCANE BAGASSE ASH (MISCBA) AND RAW BAGASSE

Release of contaminated wastewater containing toxic pollutants has adverse negative effects to the receiving water environment. Heavy metals are non-biodegradable, with longer half –life and overtime, and can accumulate in living organism. Therefore, it is important to remove heavy metals from wastewater for its safe disposal. In this study, activated carbon prepared from thermal incineration of sugarcane bagasse was used in removing zinc from synthetic solution. The prepared carbon is termed as microwave incinerated sugarcane bagasse ash (MISCBA). Raw non-incinerated bagasse was also employed to compare the removal capacities of the two adsorbents (MISCBA and raw bagasse). Parameters including pH, contact time, initial metal concentrations and adsorbents dosages were examined. The results showed that pH of 6.0, contact time 3 hours and adsorbents dosage of 12 g/L were found to be optimum for zinc removal. Removal capacities of 21.05 mg/g and 13.4 mg/g were determined for MISCBA and raw bagasse, respectively. Freundlich correlation coefficients for MISCBA and raw bagasse were found to be 0.7508 and 0.9233, respectively. Langmuir correlation coefficients were 0.9231 and 0.6423, for MISCBA and bagasse respectively.

Recovery of Petroleum Hydrocarbons from Oily Sludge Landfilled Soil

Three types of experiments, based on the physical properties of oily sludge landfilled soil, were conducted to recover total petroleum hydrocarbons (TPH) from the soil. These experiments included gravity separation, solvent extraction using water, and air floatation. The oil portion was not easily separated from the wet (raw) soil because water molecules aggregate the soil particles, despite the fact that the soil was sandy. However, the drying and grinding processes destroyed the aggregates, causing the TPH recovery to increase to approximately 60% when air floatation was used. The drying process decreased the specific gravity of the soil sample, thereby enhancing the overall recovery of TPH from the soil. Although thermal desorption and/or incineration are common choices for heavily dumped sites, physical separation can recover the oil portion instead of simply removing it.

Life cycle assessment of integrated waste management systems for alternative legacy scenarios of the London Olympic Park

This paper presents the results of the life cycle assessment (LCA) of 10 integrated waste management systems (IWMSs) for 3 potential post-event site design scenarios of the London Olympic Park. The aim of the LCA study is to evaluate direct and indirect emissions resulting from various treatment options of municipal solid waste (MSW) annually generated on site together with avoided emissions resulting from energy, materials and nutrients recovery. IWMSs are modelled using GaBi v6.0 Product Sustainability software and results are presented based on the CML (v.Nov-10) characterisation method.The results show that IWMSs with advanced thermal treatment (ATT) and incineration with energy recovery have the lowest Global Warming Potential (GWP) than IWMSs where landfill is the primary waste treatment process. This is due to higher direct emissions and lower avoided emissions from the landfill process compared to the emissions from the thermal treatment processes. LCA results demonstrate that significant environmental savings are achieved through substitution of virgin materials with recycled ones. The results of the sensitivity analysis carried out for IWMS 1 shows that increasing recycling rate by 5%, 10% and 15% compared to the baseline scenario can reduce GWP by 8%, 17% and 25% respectively. Sensitivity analysis also shows how changes in waste composition affect the overall result of the system. The outcomes of such assessments provide decision-makers with fundamental information regarding the environmental impacts of different waste treatment options necessary for sustainable waste management planning.

Effective abatement of VOC and CO from acrylic acid and related production waste gas by catalytic oxidation

Waste gasses containing volatile organic compounds (VOC) are arising mainly form industrial production in which organic materials are processed. These VOC must be treated to levels so that they meet the local applicable legislation limits. Momentive specialty chemicals is a company which produces acrylic acid, acrylic acid esters, and acrylate polymers in Sokolov (Czech Republic). A mixed waste stream which contains 6,000–10,000 mg TOC/Nm3 of VOC is treated. The management would like to lower the operating costs of the thermal incineration unit used. It seems suitable in this case to replace the existing incinerator with a catalytic oxidation unit with use of a Pt–Pd/Al2O3 catalyst for VOC abatement. A full-scale unit was designed according to the waste gas composition and flow. Mass and energy balances were carried out, and it was discovered that the catalytic bed must be divided into two parts to prevent the reactor overheating and irreversible damage to the catalyst. A pilot plant was designed and implemented due to the potential threat of catalyst fouling by solid impurities and to confirm the expected conversion of VOC and CO. It also proves the long-term reliability of the catalytic reactor. The performed pilot tests confirmed that catalytic oxidation is suitable for the disposal of waste gas from acrylic acid and acrylates production (for this application and treated inlet concentration of VOC). VOC and CO removal efficiencies during pilot trials were 98.3 and 98.5 %, respectively.

Environmental Bioremediation: A Low Cost Nature’s Natural Biotechnology for Environmental Clean-up

Setting up of new industries or expansion of existing industrial establishments resulted in the disposal of industrial effluents, which discharge untreated effluents causing air, water, soil and solid waste pollution. Bioremediation is an ecologically sound and state-of-the-art technique that employs natural biological processes employing microorganisms, fungi, green plants or their enzymes to return the natural environment altered by contaminants to its original condition. Compared with other technologies, such as thermal desorption and incineration, thermally enhanced recovery, chemical treatment, and in situ soil flushing (which may require further management of the flushing water), bioremediation may enjoy a cost advantage. Not all contaminants, however, are easily treated by bioremediation using microorganisms. While bioremediation can’t degrade inorganic contaminants, can be used to change the valence state of inorganic and cause adsorption, immobilization onto soil particulates, precipitation, uptake, accumulation, and concentration of inorganic in micro or microorganisms. This manuscript delineates the general processes of bioremediation within the soil environment, factors of bioremediation strategies, genetic engineering approaches, monitoring bioremediation, and further, the pros & cons of the technique, limitations and potential of both ex situ and in situ bioremediation as viable alternatives to conventional remediation are explained and addressed.