Air pollution control residues

pains pollution control residuesINTRODUCTIONDescription of Overall Problem assembly line Pollution Control ( armored personnel carrier) residues be the solid output of the flue barbaric sermon equipment installed on incinerators (this report refers specialally to armored personnel carrier Residues from incinerators handling municipal Solid muff MSW). They compensate the fly modify from incine dimensionn (middle and fine grades) unitedly with the re genes (mainly lime and activated carbon paper) apply in the flue suck ploughment. Thus, they take aimVolatile contaminants from the original abscond (inc chlorides, alloys),Compounds created in the incineration process (inc dioxins),Further materials from the flue-gas treatment process (sulphates, together with high alkalinity). wherefore they be classified as fantastic prodigality.Approximately 170,000t/y (Technology Strategy Board 2009) of much(prenominal) residues be produced in the UK 3-4% of the total gas mass incinerated (surround Agency, 2002). This tonnage is growing as more raging is incinerated to generate electricity and heat, and to curb landfill. While change magnitude muscularity convalescence and reduced landfill atomic number 18 worth composition in themselves, achieving them has created the enigma of the violent armoured personnel carrier residues. In the UK the prevalent destination for these residues has been landfill, just this natural selection is under threat from tightening landfill Waste Acceptance Criteria, and rising landfill taxes, so revolutionary solutions be required. on that point be unlike treatment/recovery options functional for armoured personnel carrier residues. However these raise new(prenominal) concerns, primarily financial and vigor cost of treatmentGeneration of further effluentenvironmental jolt of the handle floatQuality control of the recovered materials.Objectives and stoveThe boilers suit goal is to identify cost-effec tive instruction options for armored personnel carrier residues, indoors Waste Acceptance Criteria. The ultimate accusings of implementing such(prenominal) options are shown in Requirements (Appendix 1). For this study, the specific the objectives areBriefly analyse the presentlycomings of the existing orders of treatment and disposal of armored personnel carrier residue in landfills, a ample with the barriers in the UK for re-use of armoured personnel carrier residues in various industries, such as cement aggregate, asphalt and ceramics.Propose energy- and cost-effective methods for the treatment of armoured personnel carrier residue which reduce the leachability and essence of heavy metal/dioxins present. alike suggest a supplier of technology for each treatment method proposed.Compare the cost per tonne for each option, including treatment and disposal cost (including up-to-the-minute and future landfill taxes), base on the exorbitance classification of any(prenomi nal) remaining drive off.Suggest potential re-use opportunities for materials recovered from the treatment process, indicating potential markets and revenues.The reach is focused on armored personnel carrier residues from municipal waste incineration. It is assumed that current incineration technology and operating conditions apply, with waste of current composition, egressing in residues of current composition. The objectives pretend been pursued in the context of current UK and EU dominion. This is explained in imp line of reasoningment of the waste wariness hierarchy in table 1.Notes of Figure 1Further processing leading to recovery may be in or outside the system boundary depending on whether the process is plausibly to be dedicated to this application. In either case the resulting was running gamereams are inside(a) the system boundaryLandfill operations are outside the system boundary, but the long precondition withdraw behaviour of all landfill waste exit be co nsidered, even if it sports face-offs WAC.Report structureThis report has been structured to dampen an overall review of the management options for the Air Pollution Control residue, think to provide a details of the findings related with work aiming to give recommendations on its treatment.Chapter 1. Background and scope.Chapter 2. institution to the residues, overview of study management strategies, legislative aspects, and environmental issuesChapter 3. lucubrate on the residue treatment techniques, operation principles, and development statusChapter 4. approximation on the recovery and utilization techniques, operation principles, and development status.Chapter 5. Overview of status for in stock(predicate) solutions, documentation level, assessment approach for environmental impacts, outline of burning(prenominal) aspects for consideration, soft and quantitative comparison of each treatment processes.Chapter 6. RecommendationsSystem Engineering attention Plan (SEMP) is listed in Appendix 2. This is an outline of system emergencys and mechanisms for maintaining whether the requirements are met. It will provide an overview to integrate unalike technical elements of the throw up. The plan will as comfortably describe the activities, processes and tools used to hold back an achievement of the project outcomes to the node and other stakeholders. Press Release is placed in Appendix 3 and this would work on a basis of a semi globeity campaign for the project. worry AND REGULATORY FRAMEWORK FOR armored personnel carrier RESIDUE armored personnel carrier residues generation and characteristics armored personnel carrier residues come from the cleaning process of the gaseous emissions, which are produced during the incineration. Dry and semi-dry scrubbing brush systems are used in the cleaning process and involve the slam of an alkaline material to remove acid gases, particulates and flue gas compression (Sabbas et al. 2003). Finally, fabric filters in baghouses are used, where the fine particulates, i.e. the armoured personnel carrier residues are focalized and remove from the gaseous emissions (Sabbas et al. 2003). It is estimated that APC residues represent 2-5% of the original waste on a wet basis and their doing in the UK is approximately 128,000 tonnes per annum (Amutha ranee et al., 2008). In general, APC residues from municipal solid waste incineration (MSWI) consist of fly ash, carbon and lime and contain dioxins and furans (Amutha Rani et al., 2008). They are highly alkaline materials (pH 12.0-12.6) and they comprise signifi poopt submergence of heavy metals, brininesss and micro-pollutants (Sabbas et al. 2003). Depending on the initial waste composition, the incinerator and the air pollution control system, their composition may vary significantly (Amutha Rani et al., 2008). The typical range of APC residues composition is shown in table 2.The APC residues are characterized as uncertain wastes (190107* , according to the EWC) due to their chemical substance contented and their impact on the environment, primarily by take away.Regulatory FrameworkIntroductionRegulations and legislation on waste management in the UK have evolved substantially over the years as a result of identification of new pollutants, public health and environmental concerns, economics and technological advancement (Pocklington, 1997 and McDougall et al, 2001). This impudence suggests that legislation and regulations play a major role in ensuring sustainable waste management. In addition, the establishment of legislation on waste management shows the radically changing perception of humankinds and communities towards the environmental impact of human activities (Pocklington, 1997). Today, regulations and legislation provide a manikin for efficient handling of raving mad wastes such as APC residue. Amutha Rani et al (2008) observed that sustainable management of APC residues depend on the implementation of UK and EU waste management legislation.The Existing regulatory and legislative hurlwork for managing APC residues in the UKAbout 80% of the environmental legislation in the UK have their origins in the European Commission laws (Pocklington, 1997). The existing legislative and regulatory framework for APC waste management in the UK and EU includeWaste Incineration directive maskconnected Pollution Control directiveLandfill Directive and ensuing waste acceptance criteria/procedureEA guidance on the classification of hazardous wasteWater Framework DirectiveHowever, the discussion on the regulatory and legislative framework for this project focuses mainly on the UK Landfill directive and EA guidance on classification of hazardous wastes. These subjects are pertinent within the boundary of this project more so as Landfill disposal is common in the UK. in any case IPPC directive is discussed briefly to highlight the roles public participation and deployment of best available techni ques in butting our objectives.The key objectives of these legislation and regulation are to snub the amount of APC residue generated and improving the property of exhaust gas (McDougall et al, 2001)Reduce the amount of APC going to Landfill (EA counselling on landfill, 2006) rule out environmental impact (ESA 2004)Reduce the risk of human harm (US subject area Research Council 2000, ESA 2004)This plat illustrates the relationships between the realized regulatory framework and stages in the APC management process. There is no specific legislation natural covering recovery or reclassification of APC residue in the UK (ESA 2004). Quina et al (2008) withal points out that legislation for recycling APC has not yet been established in the UK.The Integrated Pollution Control Directive Directive 2008/1/EC concerning integrated pollution frustrateion and controlThis Directive aims at establishing means to prevent or reduce emissions into air, water and land (IPPC, 2008). accordingl y this directive is crucial as it suggests various methods of incineration and treatment that could reduce the impact of APC residues on the environment during incineration, treatment or landfill. The IPPC Directive is establish on four principles namelyBest Available Technique (BAT)Integrated waste managementFlexibilityPublic participationThe BAT refers to the approximately effective methods of operation that would reduce environmental impact and enhance results such as making residues from incineration less hazardous. In the BAT, optimizing resources and harnessing or saving energy are prior(prenominal)itized (Gargulas N. and Mentzis A, 2007). Also, the BAT is flexible and no terms are enforce since it recognizes that different conditions apply in different cases. The Best Available Techniques eccentric (BREF) is a reference document on technical input necessitate to determine the BAT to be adopted. This BREF contains technical information on available means of treating APC re sidues such as sintering, vitrification, stabilization and solidification. This project has considered the alligatored to APC treatment and these methods are discussed in chapter 3. However, there are no BATs available for landfills. Notwithstanding, Landfill operators and APC treatment plants require permits issued by the Environment Agency with public support to ensure that there are no health or environmental impacts as a result of their activities (Macleod C. et al 2006 and IPPC 2008).The role of the public is crucial in this directive. Article 15 of the Directive, gives the public full privileges to participate in decision making processes leading to the result of permits for installation of plants, and for carrying out technical and administrative changes. This aspect is very important especially in the proper project planning and execution (see SEMP). Therefore the installations of APC treatment facilities and the method involved are tailored to meet public requirements as well as legislative requirements. All hazards infixed in operating APC treatment facilities shall be made cognize to the public in accordance to this directive. Also the outcome of deference bear witnesss on treatment facilities with regard to environmental impact shall be made public (IPPC 2008). Thus, it can be argued that since the public are key stakeholders in this project, better public perception is call for in accordance with the IPPC directive to ensure sustainable management of APC residues.Environment Agency guidance on classification of hazardous wasteThe essence of this guidance is to distinguish different kinds of wastes ground on their physical and chemical properties which include their toxicity or hazardous nature.The waste Waste Directive (HWD), council directive 91/689/EC and the Revised European Waste Catalogue (EWC) form the regulatory framework for this guidance. The HWD aims at defining hazardous wastes to ensure the correct management and regulation o f such waste (EA Hazardous Waste 2008, pg 5). This directive identifies 14 hazardous properties of wastes, thus hazardous wastes are classified H1 H14 according to their hazardous properties (EA, Hazardous waste 2008). The EWC engrave is derived from the industry and process producing the waste, and the type of waste (EA hazardous waste 2008).APC residues are categorized as hazardous wastes with dictatorial entry (Rani et al 2008 and ESA 2004). Under the European Waste Catalogue (EWC), APC residues fall under the category of wastes from incinerators (waste management facilities) that have a generic wine code 19. The specific code for solid wastes generated from gas treatment such as APC residues is 19 01 07.Wastes resulting from the treatment of the APC residues such as the partially stabilized APC residue, the vitrified material etc are also categorized as hazardous with absolute entry (EA hazardous waste 2008). However, when tests confirm that the constituents of case-hardene d waste have become less or non hazardous, they can be reclassified as hazardous wastes with mirror entry or non-hazardous as the case may be(EA Hazardous waste 2008). Solidified and part stabilized wastes are coded 19 03 06 and 19 06 04 respectively with absolute entries, while vitrified wastes from flue gas treatment are assigned the code 19 04 02.The Landfill Directive 1999/31/EC of 26 April 1999 on the landfill of wasteThe primary objectives of the landfill directive areTo reduce waste going to landfillthe prevent or minimize environmental impact as a result of waste disposalStringent measures and standards have been set to reduce the send and reliance on landfill (EA guidance on landfill, 2006).Landfills are classified into trine categories non-hazardous, inert and hazardous landfills (Landfill (England and Wales) Regulations, 2002)For APC residues, a key requirement in the Directive prior to landfill is to perform tests to determine its long term and short term remove beha viour and to carry out treatment to reduce its toxicity (EA guidance on landfill, 2006). This project suggests that the need for treatment of APC residues augments the case for exploring potentials for recovery or reclassification of the residues.Article 6 c (iii) of the Directive reflects our aim to make APC residues at least stable non-reactive hazardous wastes (SNRHW) or completely non-hazardous through efficient treatment techniques such as vitrification, washing, stabilization and plasma technology. SNRHW are known to have low withdraw potentials (EA guidance on landfill, 2006). Treated APC residues with take behaviour identical to those of non-hazardous waste can be habituated at designated non-hazardous landfill subject to meeting the relevant waste acceptance criteria (EA guidance on landfill, 2006 and Landfill (England and Wales) Regulation, 2002).APC residues mustiness meet the waste acceptance criteria (WAC) for a designated landfill after treatment. Schedule 1 of t he Landfill (England and Wales) (Amendment) Regulation 2004, stipulates the procedure and criteria for disposing or accepting waste at landfills.Waste Acceptance Criteria and ProcedureThe WAC is elaborately designed to deal with the technical requirement of wastes such as APC residues designated for landfills in the UK (England and Wales). It also aims at compulsory the disposal of wastes into landfill which is a common practice in the UK. Technically, the WAC ensures that the numerical take away characteristics of APC residue are determined prior to disposal at landfill (EA focusing on Landfill 2006). Thus, after their mandatory treatment, APC residues must meet the relevant waste acceptance criteria before they are accepted into landfill. The withdraw characteristics include the elements and compounds in APC residue and their leaching properties (in mg/kg or L/S) and the hazardous nature of the APC residue (EA Guidance on Landfill, 2006). The Environment agency is responsible towards ensuring that the criteria for particular landfills are met. anterior the WAC is the Waste acceptance procedure.The Waste acceptance procedure for APC requires primary characterization, compliance testing and on- come in verification (EA Guidance on Landfill 2006). The elementary characterization is done to determine the physical and chemical characteristics of the waste (EA Guidance on Landfill 2006). Incineration plants are responsible for carrying out the basic characterization of the APC residues since they produce the APC while the landfill operator ensures that compliance testing and on-site verification are done (EA Guidance 2006). Approved tests are de spring in schedule1 part 2 of the landfill regulation 2004 and they include tests for determining treated APC composition and leaching behaviour. The compliance tests are carried out to verify if leaching limit levels predicted in the basic characterization are credible. overly exploring opportunities for reuse of APC residues and recovery of valuable materials from the residues, this project also aims to treat APC residues to meet at least the waste acceptance criteria for SNRHW to change disposal at a non-hazardous landfill. Amendment 14 of the Landfill (England and Wales) regulation 2004 states the criteria for disposing SNRHW in the non-hazardous landfill.DiscussionsThere is no specific legislation on the reuse of wastes such as the APC residues in the UK. Notwithstanding, the UK without incineration network (www.ukwin.org.uk) tagged the use of fly ash and APC residues for construction works as irresponsible. Thus it can be suggested that re-use is implied in this clause as well. However, if it is well proven that APC residues can be managed sustainably without any long or short term environmental repercussions, it will pave way for debates to strengthen the existing regulatory frame and also re-focus the views of environmental activists toward the prospects in the residues.ESA report (2 004) argues the provision of regulatory inference by the government is necessary in enhancing investment towards sustainable management of APC residues. The report also suggests that investments will focus on true(p) APC treatment technologies. There are several scientific developments for managing APC residues pioneered by waste management companies such as Techtronic in the UK.environmental problems and management strategiesMost of the APC residues (around 88%) (Environmental Agency, 2002) produced in the UK, are dispose of into landfills. During their disposal or any kind of utilization or handling, a number of environmental impacts can be caused. ashes and splosh emissionsDust emissions are represented as a potential risk, due to the size of it of the APC residues particles (0.001-1 mm) (Sabbas et al., 2003). Despite the easily dispersion of these fine particles, a ken by the Environmental Agency at a number of landfill sites in the UK testifies that their concentrations a re within the recommended air quality objectives (Environmental Agency, 2002).Gas labor is other potential environmental impact related to the disposal of APC residues. Gas is produced by metallic aluminum hydration (Sabbas et al., 2003) and because of that, some explosions have been reported (Sabbas et al., 2003). However, the production of gas is significantly lower compared to the production of the municipal solid waste landfills, due to their low biodegradable content of the APC residues. take productionThe major environmental impact is the leaching production of APC residues The leaching behaviour of the elements present in APC residues is the main source of environmental concern. Leachates can cause pollution of soil, groundwater and surface water bodies. The leaching sort of the APC residues is very complex and depends on a lot of parameters. The pH and the liquid to solid (L/S) ratio of the residues that will occur in the landfill site are important factors which affect d etermine their leaching behaviorbehaviour as well as the approachability of the elements which are contained in the APC residues.The pH depends on the characteristics of the leaching fluid and the waste, i.e. APC residues, and is the key factor of many elements leachability. Leaching of most major elements (e.g. Al, Ca, S, Mg) and heavy metals (e.g. Cd, Pb, Zn) are strongly pH-dependent (Astrup et al., 2006). This dependency of the pH causes a significant difficulty on the prediction of the leaching behaviorbehaviour. Generally, APC residues carry on their pH in alkaline determine for a long time (many thousands of years) (Astrup et al., 2006). However, their pH decreases as the time passes and the APC residues are washed by the infiltrating water (the neutralize capacity decreases) (Astrup et al., 2006). Thus, the prediction of the landfills pH and thereby the leaching behaviorbehaviour of the residues in over a long term period is complex.The L/S ratio represents the amount of t he leachate that comes in collision with a given amount of APC residues (Sabbas et al. 2003 pp what page?) and depends on the characteristics of the APC residues and the climatic conditions, the hydrology and the hydrogeology of the area (Sabbas et al. 2003). Usually, as the time of disposal passes the value of the L/S ratio becomes higher for a particular application site. delinquent to this contact the properties of the waste as well as the leaching behaviorbehaviour of the waste change. Thus, the value of this ratio is a very important parameter for the leachate content.The availability for leaching is a parameter, which characterizes the particular waste and represents a fraction of the total content of contaminants in the waste itself (Sabbas et al. 2003). The typical set of the availability for the APC residues are shown in table 2 and they can provide a theoretical estimation of the maximum release of a contaminant in a period of 1000 to 10000 years (Sabbas et al. 2003).Th e prediction of the leaching behaviour and the evaluation of the environmental impact of APC residues are based on leaching tests. Leaching values for the APC residues arising from leaching test are summarized in table 4.The first leachate from APC residues is usually characterized from alcohol-soluble seasons (e.g. chlorides, hydroxides of calcium, sodium and potassium) and trace element such as Pb and Mo (Sabbas et al., 2003). Contrary to the high solubility of this elements, the solubility of toxic organic compounds is believed to be not high due to their hydrophobic nature and their low concentration in APC residues (from properly operated MSWI plants) (Sabbas et al., 2003).Long term leachate concentrations are usually lower than the initial or they may remain atto the same level. The notwithstanding exceptions are the elements Al and Zn, which concentrations in the leachate are increase d inover a long term period (Astrup et al., 2006).As it is explained above the leaching behaviour of the APC residues depends on the environmental conditions and changes during the time of the disposal. Thus, an analytical prediction of the long term leaching behaviour is very difficult and it should be based on a combination of information on leaching principles, leaching tests, field measurements, simulation of mineral changes and speciation (Sabbas et al., 2003 page number pls). Due to the complexity of the long term leaching behaviour, the data available in literary productions are limited.Management of APC residuesIn the UK the disposal of any waste to landfill is regulated (see regulations section). Generally, the landfills are classified as suitable for hazardous, non-hazardous or inter wastes and, for each of these types of landfill, particular leaching limit values (Waste acceptance criteria, WAC) are defined and should be achieved for any waste are to be landfilled. circuit card 5 shows the leaching limit values (WAC) for the three types of landfill sites and if they are compared with the values in table 4, it becomes obvious that APC residues cannot be landfilled without a prior treatment.And non-hazardous waste deposited in the same cell.Either TOC or LOI must be used for hazardous wastes.UK PAH limit values are under development.following the recent consultation exercise the UK Govt may review the limit values in tow years time (2006).If an inert waste does not meet the SO4 at L/S 10 limit, alternative limit values of 1500 mg/l SO4 at C2 (initial eluate from the percolation test) prEN 14,405 and 6000 mg/kg SO4 at L/S10 (either from percolation test or bach test BS EN 12457-3), can be used to demonstrate compliance with the acceptance criteria for inert wastes.The values for TDS can be used instead of the values for Cl and SO4.Or DOC at pH 7.5-8.0 and L/S 10 can be determined on pr EN 14429 (pH dependent test) eluates.Disposal to landfill (Amutha Rani et al., 2008)APC residues are involved with wastewater to form a solidified pro duct. During this treatment the residues react with the carbonic acid gas from the atmosphere reducing the pH to values between 8 and 9. This commixture also eliminates the dispersion of the APC residues particles. After this treatment, the APC residues reach the WAC and they are landfilled into monofill cells at a hazardous waste landfill. This process is used by a treatment plant in GloucesstershireGloucestershire, from which most of the APC residues treated by this method in the UK are coming. Storage in salt minesIn this disposal method the APC residues are loaded in sealed capsules and pitted 170m below the surface (Amutha Rani et al., 2008). The disposal in salt mines can take place for a long term. They are characterized as well isolated, very dry, with stable atmosphere and natural gas-impermeable salt layers (Clement, 2000). Salt mine for this purpose is located in Cheshire, England, where a major percentage of the APC residues, produced in the UK, are stored (Amutha Rani et al., 2008).Use in waste acid treatment (Amutha Rani et al., 2008)Due to the mixing of waste acid (usually HCl) and APC residues, the lime content of the APC residues is convertedsed into less hazardous components (CaCl2) and the concentrations of Zn and Pb are reduced. Furthermore, the pH is at high levels, preventing the salts release. Thus, the last(a) mixture from this process is non-hazardous and it is described as sludge from a physico/chemical treatment it is classified as EWC code 190206 and can be disposed of in non-hazardous landfills.TREATMENT TECHNIQUESAsh Washing ProcessDescriptionThe objective of Ash washing process is to extract a number of minerals from the APC residue obtained after Municipal Solid Waste incineration and thereby derogate the leachability of various compounds remaining in the residue. The process also aims to improve the quality of the residue obtained for further re-use applications or to reduce the overall content of waste going to the landfill . According to Quina et al (2001), ash washing, acid leaching, electro-chemical process and thermic treatment are some of the most widely used methods for extracting metal values from the APC residues.The separation techniques studied in this section are ash washing with MgSO4, bioleaching using Asphergillus niger fungi and leaching using extracting agents. severally process has different prerequisites, operation time and cost, objectives and risks associated with them.Ash Washing With MgSO4Chimenos et al (2005)The process aims to apply the optimum parameters for washing APC residue by utilising minimum energy and water. This process uses multi-stage washing process to diminish the leaching of chloride and sulphate salts present in APC residue and thereby ensuring that the amount of harmful substance present in wastewater is reduced. The wastewater produced is recycled and re-used in the process using employing a rapid spray evaporation technique which runs on the waste heat produc ed from pumps, turbines and incineration furnace. Figure 3a showsrepresent the overall process diagram of operation.The research conducted by Zhang et al (2008) shows that the leachability of the heavy metals and chlorides present in APC residue depends on its pH level. The pH of the solution, when MgSO4 is added during the washing process, may be controlled by the formation of gypsum as shown in Eq(1).Ca(OH)2 + MgSO4 CaSO4 + Mg(OH)2..(1)BioleachingQ.Wang et al (2009)This process is considered to be a biohydrometallurgical approach to extract heavy metals from APC residue. It is considered to be a green technology because of it makes use of the natural ability of microorganisms to break downward(a) solid compounds into soluble and extractable form by enzymatic oxidization or reduction. The process uses the acids secreted by Aspergillus niger fungi such as oxalic acid, citric acid and gluconic acids to extract the heavy metals present. Water-washing was is used as a pre-treatment b efore the bioleaching process to reduce the bio-leaching period from 30 to 20 days and to extract the maximum amount of chloride and sulphate salts. Figure 4 shows an overall process diagram for the bioleaching process. Bioleaching is a low cost and low energy consumption approach.Leaching Using Extracting AgentsFedje et al (2010)This process uses leaching agents other than water for extracting heavy metals like Zn and Pb. The efficiency of the extraction agent depends on heavy metals of interest, the concentration of the extracting solution, the pH and the liquid/Solid ratio used. The goal of the process is obtain a solution in which the concentrations are high enough to enable further separation or recovery.The leaching media used for this process are3M HNO3 L/S = 50.1 M EDTA with pH adjustment L/S = 53M NH4NO3 L/S = 5The choice of these leaching media was based on their ability to form a complex with metal ions. Table 6 compares the efficiency of the aforesaid(prenominal) leachi ng agent in extracting the heavy metals from APC residue. Figure 5 represents the overall process diagram.The most widespread leaching method used for APC residues is acidic leaching using strong mineral acids such as HCl and H2SO4. However, due to the high alkalinity of APC residues, large amounts of acids are needed which results in trouble with storage and handling.Moreover, the reaction of APC resid