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Hazardous Waste Management

CEV 414 E

  • Every year, billions of tons of solid wastes are discarded into our environment. These wastes range in nature from common household trash to complex materials in industrial wastes, range in nature from common household trash to complex materials in industrial wastes, such as hospitals and laboratories.

  • Waste is defined as 'any material that are no longer desired and has no current or substance that has been discarded or otherwise designated as a waste material, or one that may become hazardous by interaction with other substances

  • Hazardous waste may either be in the form of solid, liquid, semi-solid or contained gaseous material (UNEP 1982).

  • Turkey had also extricated several catastrophes similar to other countries.

  • In 1970, hazardous wastes were imported to be utilized as a fuel from foreign countries. People were unaware of the adverse effects of the gas formed through burning.

  • In 1980 a ship named unaware of the adverse effects of the gas formed through burning. In 1980 a ship named Petersberg had spent 2 moths in Marmara and Black sea to discharge its wastes

  • It was not the legislations or governmental acts but the common sense of people that terminated the improper actions.

  • Great number of fish and other living organisms were found dead at the sea shore of Marmara Sea between Kartal and Kadky region.

  • Drums that were full of hazardous waste were found in Black Sea near Samsun.

  • Hekimba uncontrolled landfill area was exploded and 40 people died in Istanbul.

  • A gold mine project, which used cyanide extraction and proposed waste dam is still being problem to make Environmental Impact Assessment Report due to lacking in regulations and their enforcements. Growing concern about the environment in Turkey has focused attention in recent years on the need for vigorous Government action.

  • In consequence, substantial administrative measures have been introduced to improve the environmental concern and to provide a more efficient and rational basis for the management of wastes from all sources.

  • In 1995 Control of Hazardous Waste legislation has been passed to provide a control over wastes that are generated (Control of Hazardous Waste Regulation-27.08.1995).

  • The Control of Hazardous Waste Legislation of Turkey has been based on the idea of regulatory approach of EPA. The Turkish legislation then becomes a reproduction of the Resource Conservation and Recovery Act (RCRA).

  • Studies have not been made to see whether the legislation is suitable for Turkey or not. Thus the legislation cannot be carried out to protect environment due to inappropriate technical evaluations, misplaced definition of effects, contradictions and intersections among the lists in terms of criteria, source, characteristics, as well as subjective descriptions. Practices which will lead to environmental protection legislation's have to be based on political proposals, project planning as well as legal alterations for their ease of applicability.

  • Classification

  • Classification with Respect to Characteristics

  • Solid waste has to be examined whether it exhibits a characteristic that makes it hazardous.

  • All persons who generate a solid waste have to ascertain whether their wastes exhibit one or more of the characteristics as follows: Ignitability, Corrosivity, Reactivity, Toxicity (Hall and others 1993, UNEP 1983, EPA 1990a).

  • Ignitability

  • The hazardous waste characteristic of ignitability was established to identify solid wastes capable during routine handling of causing a fire, or provoking a fire once started.

  • A solid waste is deemed to exhibit the characteristics of ignitability if meets one of the four descriptions. It is determined using the test method specified in ASTM Standard D-93- 79 or ASTM Standard D-3278 (EP A 1990a, DEPE 1992, Meyer 1989).

  • Corrosivity

  • Corrosive substances may exhibit extremes of acidity or basicity or a tendency to corrode steel. Wastes capable of corroding metal could escape their own containers and liberate other wastes.

  • In addition, wastes with a pH at either the high or low end of the scale can harm human tissue and aquatic life and may react dangerously with other wastes. It is determined using the test method specified in EP A 600/ 4- 79-020.

  • Reactivity

  • Reactive substances are those, which are extremely unstable and have a tendency to undergo violent chemical change or explode during stages of its management.

  • The regulation lists several situations where this may happen which guarantee specific consideration like the behavior of the substance when mixed with water, when heated etc. Instead of developing a precise scientific description of this characteristic, EPA has publicized a descriptive, prose definition as a suitable test protocols for measuring reactivity are unavailable (EPA 1990a, 1990b, Meyer 1989).

  • Toxicity

  • One of the most significant dangers posed by hazardous wastes is the leaching of toxic constituents (of land disposed wastes) into the ground water (Christensen 1971, EPA 1981).

  • EPA designed the (Toxicity Characteristic) TC Toxicity, to identify wastes that pose a threat to human health or the environment resulting from ground water contamination by simulating the leaching process that occurs in a municipal landfill.

  • EP A treats mixtures of a characteristic hazardous waste and a solid waste differently than it does a mixture of a listed hazardous and solid waste. Toxicity can be determined by fish bioassay tests. Toxicity value defined by LC50.

  • The LC50 for a contaminant is the concentration being lethal to 50 per cent of an exposed population of test fish with a given time. For estimation of LCso values, various procedures using different test species and experimental conditions can be found in literature

  • (EPA 1990a, 1990b, OECD 1982, Council on Environmental Quality 1971, Manahan 1990).

  • The entire volume of a mixed waste is treated as hazardous if; the listed hazardous waste in the mixture was not listed separately due to its hazardous characteristics or mixture does not consist of certain specified hazardous wastes.

  • Building Up Criteria to Define Hazardous Waste

  • Waste can have the potential of being hazardous due to; substances present in the waste, their concentration, their chemical reactivity, physical form in which the substances are present, quantity and recurrent rate of arising of potentially hazardous material, mobility and persistence of the potentially hazardous materials in the environment in which they are placed, targets available in that environment and their vulnerability to the potentially hazardous materials, possibility of remedial measures and their costs.

  • The short-term acute and long-term environmentally hazardous properties of a waste are a function of the chemical species present. In some cases, wastes have well-defined dangerous properties and are unequivocally hazardous. Such wastes generally result from the use of commonly encountered chemical compounds. The majority of wastes considered, however are likely to be complex mixtures, which do not readily lend themselves to chemical characterization (UNEP 1982, EPA 1990a, 1990b, Hall and others 1993).

  • Composition

  • Concerning the composition of the waste, the individual components of a waste should be known before a complete assessment of its hazard potential is made.

  • This knowledge however is often very difficult and may be impossible in practical terms, particularly for solid wastes. To demand, either directly or by implication, that all waste be analyzed for all potentially hazardous species is quite impractical (UNEP 1982).

Physical Form

  • Three major categories of wastes based upon their physical forms are; organic materials, aqueous waste and sludge (UNEP 1982).

  • These forms largely determine the course of action taken in treating and disposing of the wastes.

  • It is relatively easy to deal with wastes that are not mixed with other kinds of wastes. The physical form of the waste as relevant to a consideration of both potential acute or long-term environmental hazards.

  • In general, liquid or sludge waste is more liable to cause water pollution problems than is solid waste. Where an inhalation hazard exists, as with asbestos, fibrous waste is inherently more dangerous than is matrix-bonded asbestos waste, e.g. asbestos cement. Small particle size by itself may confer hazard on a material that is non- hazardous in larger pieces; many finely divided metals are acutely hazardous while the massive material is harmless.

  • Solids formed by cooling from the molten state may often have their potential hazard much reduced, e.g. metal slags are often considered non-hazardous despite often relatively high concentrations of toxic metals (UNEP 1982).

  • Quantity

  • The quantity of the waste and its recurrent rate of arising are important. The handling and disposal of a few hundred kilograms of a particular waste as and isolated arising may demand totally different solution to the disposal of similar material arising on a regular basis in quantities, which may be orders of magnitude greater or smaller.

  • Some countries have introduced requirements that a waste must be present at more than a predefined minimum quantity before it is considered hazardous. This approach is administratively convenient as it reduces the amount of paperwork associated with the regulatory process, but has certain dangers (UNEP 1982).

  • The potential for environmental damage at a waste disposal site is c1early related not only to the concentration of the substance released but also to the total quantity released at a given time (Kolaczkowski and Crittenden 1987, Exner 1 989).

  • Acute Hazard

  • The acute hazard posed by the waste may be expressed in terms of oral, inhalation or dermal toxicity, flashpoint, explosivity, concentration of known corrosive species, etc. Physical characteristics, such as vapor pressure and boiling point, may be important.

  • To avoid dangerous interactions with co-deposited materials, highly reactive materials, e.g. powerful oxidants, should also be considered. However, unless toxicity tests are performed on the waste itself, acute hazards posed by the waste can only be predicted by the hazards of its components.

  • Long-term Hazard

  • The long-term hazard posed by the waste will depend upon the chosen disposal route.

  • For example, such properties as volatility, water solubility and solubility in organic chemicals will influence the mobility of wastes deposited in landfill. The persistence of a particular material will depend upon its vulnerab1ty to various natural breakdown mechanisms like microbiological, photochemical, oxidation/reduction, etc.

  • The toxicity of a deposited material and its metabolites and organoleptic factors, such as taste and smell, are relevant.

  • Exclusive List of Hazardous Wastes.

  • One alterative approach to the problem of adequately defining what constitutes a hazardous

  • waste is to draw up a list of known wastes, which present no significant short-term handling or long-term environmental hazards, and to define hazardous waste by exclusion, as any wastes not listed.

  • While one advantage of the exclusive list approach is that it is relatively simple to ensure that the listed materials are not hazardous, materials not listed and, marginally so. In addition, when reliance is placed upon qualitative, subjective criteria, different interpretations will inevitably possible.

  • Thus, waste producers, waste disposers and regulatory authorities are denied the certainty they need.

  • Inciusive List of H azardous Wastes

  • More widely employed for regulatory purposes are listings of hazardous waste, either with or without accompanying criteria. This approach is currently used in Belgium, Denmark, France, the Federal Republic of Germany, the Netherlands, Sweden, United Kingdom and the United States.

  • The lists comprise wastes from certain industries, wastes containing specific components or specific waste streams identified by the processes from which they originate. The United States also uses this approach but combines it with prescribed test procedures, such that hazardous wastes are so defined by their presence in a list of waste materials or providing certain results when subjected to the test protocol (EP A 1980, EP A 1990a, 1990b, Hall and others 1993).

  • The inclusive list offers a greater degree of certainty but suffers from the disadvantage that exclusions may well be significantly hazardous. The greater the degree of specificity, the more the list approaches catalogue proportions (UNEP 1983).

261.31 Hazardous wastes from non-specific sources.

F001 .. The following spent halogenated solvents used in degreasing: Tetrachloroethylene,trichloroethylene,methylene chloride, 1,1,1-trichloroethane, carbon tetrachloride,and chlorinated fluorocarbons; all spent solvent mixtures/blends used indegreasing containing, before use, a total of ten percent or more (by volume) ofone or more of the above halogenated solvents or thosesolvents listed in F002,F004, and F005; and still bottoms from the recovery of these spent solvents andspent solvent mixtures.(T)

F006 ... Wastewater treatment sludges from electroplating operations except from the followingprocesses: (1) Sulfuric acid anodizing of aluminum; (2) tin plating on carbonsteel; (3) zinc plating(segregated basis) on carbon steel; (4) aluminum or zinc-aluminumplating on carbon steel; (5) cleaning/stripping associated with tin, zinc andaluminum plating on carbon steel; and (6) chemical etching and milling of aluminum. (T)

261.32 Hazardous wastes from specific sources.

Wood preservation:

K001 ...... Bottom sediment sludge from the treatment of wastewaters from wood preservingprocesses that use creosote and/or pentachlorophenol.(T)

Inorganic pigments:

K002 .......Wastewater treatment sludge from the production of chrome yellow and orange pigments.(T)

K003 .....Wastewater treatment sludge from the production of molybdate orange pigments ...... (T)

K004 ..... Wastewater treatment sludge from the production of zinc yellow pigments ................. (T)

K005 ...... Wastewater treatment sludge from the production of chrome green pigments ............ (T)

K006 ...... Wastewater treatment sludge from the production of chrome oxide green pigments(anhydrous and hydrated).(T)

K007 .....Wastewater treatment sludge from the production of iron blue pigments ..................... (T)

K008 ......Oven residue from the production of chrome oxide green pigments ............................ (T)

P021 592018 Calcium cyanide

P021 592018 Calcium cyanide Ca(CN)2

P189 55285148 Carbamic acid, [(dibutylamino)- thio]methyl-, 2,3-dihydro-2,2-dimethyl- 7-benzofuranyl ester.

P191 644644 Carbamic acid, dimethyl-, 1-[(dimethyl-amino)carbonyl]- 5-methyl-1H- pyrazol-3-yl ester.

P192 119380 Carbamic acid, dimethyl-, 3-methyl-1- (1-methylethyl)-1H- pyrazol-5-yl ester.

P190 1129415 Carbamic acid, methyl-, 3-methylphenyl ester.

P127 1563662 Carbofuran.

P022 75150 Carbon disulfide

P095 75445 Carbonic dichloride

P189 55285148 Carbosulfan.

U002 67641 Acetone (I)

U003 75058 Acetonitrile (I,T)

U004 98862 Acetophenone

U005 53963 2-Acetylaminofluorene

U006 75365 Acetyl chloride (C,R,T)

U007 79061 Acrylamide

U008 79107 Acrylic acid (I)

U009 107131 Acrylonitrile

U011 61825 Amitrole

U012 62533 Aniline (I,T)

U136 75605 Arsinic acid, dimethyl-

U014 492808 Auramine

U015 115026 Azaserine

Management Strategies for Identification

  • Management strategies also play an important role in defining a hazardous waste. These steps may include; the source of the waste, generators, waste transport, waste storage, appropriate treatment technologies, Final disposal.

  • Once a waste is identified as hazardous, quantities must be tracked. In order to identify whether a solid waste is hazardous or not, generator should have to refer to lists or various tests. Effective identification and labelling by the generators are essential for control. Mismanagement of Hazardous Waste leads to a 'cradle to grave' control system (UNEP 1983).

  • This system regulates the hazardous waste from the time it is first generated through the transport to final treatment or disposal. Some hazardous wastes require special control from the time of generation through their transportation, temporary storage, treatment and disposal.

  • Hazardous wastes should be identified and disposed of in a manner that will most effectively protect the environment. The quick and dirty approach is still employed today by putting wastes in open dumps, landfills or in warehouses. Hazardous wastes can either be tracked according to the amount that is generated (EPA 1990a, DEPE 1992, Phifer and McTigue 1989):

  • 1.Small quantity generators, 2.Large quantity generators

  • or can be classified according to their sources:

  • Point sources, 2.Diffuse sources.

  • Industrial hazardous wastes are a unique problem because they are transportable, and pose hazard either in short or long term basis. Thus it will be appropriate to further classify the wastes:

  • Industrial hazardous waste generators

  • Non-industrial hazardous waste generators.

  • Standard Industrial Classification (SIC) codes have been employed to identify groups of hazardous waste generators. The office of Management and Budget Manual establishes these codes.

  • However in some cases they were found to be inadequate. The manual and codes do not identify individual facilities or potential generators. They are often not descriptive or inclusive as is necessary for a complete hazardous waste survey.

Collection and Transport

  • These play an important role particularly in terms of disposal cycle and in control.

  • Most incidents of improper disposal of hazardous waste have occurred during transport and may result from disposal contracts between the waste generator and hauler rather than between the waste generator and disposer.

  • Thus, any reduction of cost for disposal (e.g. by means of improper dumping) will increase the profit of waste haulage firm.

Management, Treatment and Disposal

  • Waste Reduction

  • Waste sorting and Recycling

  • Waste transfer and Transboundry movement

  • Energy and Material recovery

  • Thermal Processing/ Waste Incineration

  • Ultimate Disposal/ H.W. Sites

Physical Treatment

  • Lagooning and tank storage are widely used to seperate oil and water from mixed wastes

  • Solidification fixation processes are generally used as pretreatment prior to landfill disposal

  • Air flotation and various filtration and centrifugation techniques

Chemical Treatment

  • Cyanide Oxidation

  • Heavy Metal Precipitation

  • Hexavalent Chromium Reduction

  • Acid neutralization

Biological Treatment

  • The in-plant biological treatment of dilute aqueous effluents is well established, and m.o. Have been developed to selectively degrade specific toxic chemicals

  • Composting may also be useful for certain organic chemical products


  • Landfill

  • Incinaration

  • Dumping at sea

  • Underground disposal

  • Deep-well disposal

Coast of Waste Treatment and Disposal

Table 4. Cost to Western Europan Chemical Industry for treating and disposing

of waste by different methods : Spring 1979

Methods Cost Range

US $ /tonnes

Simple Disposal to land 1-20

Disposal to land in a site lined with plastic sheet 10-50

Underground disposal to dropping into old wells or mines 20-150

Land disposal after encapsulation either by mixing the waste 10-100

with cement or other agent or by incarcerating whole drums

in cement

Coastal sea dumping from ships or 5-15

Deep-ocean dumping beyond the continental shelf 10-150

Simple incineration (without significant heat recovery) 30-150

Incineration with alkaline stack scrubbing 100-350

Incineration onboard ship at sea 50-350

All types of chemical treatment and, in particular :

Destruction of cyanide by hypochlorite 300-500

Reduction of chromic acid 100-300

Destruction of cyanide (catalytic) 200-500

Hazardous Waste Definition

  • Hazardous waste is a/any specialized and listed waste;

    • which has acute or chronic hazard potential described as Flammable ,Toxic, Corrosive and/or Reactive criteria,

    • Which should be managed with all together with the social, political and economical aspects of the eco-system instead of convantional tratment and disposal techniques because of its composition, constituents, physical form, fate and transport in the environment

    • Which may be in forms of solid, liquid, slurry, sludge and pressurized gas

    • Which may be a/any hazardous substance that has been discarded or otherwise designated as a waste material, or one that may become hazardous by interaction with other subtances


Ilhan Talinli , Rana Yamanturk, Egemen Aydin, Sibel Basakcilardan


  • Hazardous wastes, the main drawbacks of industrialized world, are still keeping their importance because of their potential hazard to human health and environment, when improperly treated, stored, transported and/or disposed.

  • The unique solution for that kind of wastes is to manage and control them from the point of generation to ultimate disposal.

  • The legislators of each country should create regulations enforcing the safe management of the hazardous waste.

  • These regulations should appoint the hazardous waste generator as a legal entity who must ensure that the waste is managed in accordance with its regulatory standards [1].

  • But a generator who will comply a regulatory program demands a far more precise definition of the term hazardous waste.

  • The term hazardous waste, originated from US Environmental Protection Agency, does not have a unique and universally accepted definition but the identification of hazardous waste in each country is based on the four characteristics 1) ignitability 2) corrosivity 3) reactivity 4) toxicity [2].

  • Although every country has its own regulatory program, the most common violation of the rules, whether willful or inadvertent, is because of the definition of the waste as hazardous waste [3].

  • In most of the countries, the board responsible from the hazardous waste management defines the hazardous waste by using two different mechanisms (1) by listing (2) by identifying characteristics and these definitions are commonly based on the Subtitle C of Resource Conservation and Recovery Act (RCRA) which is the most extensive study done about hazardous waste management.

  • Using lists to define hazardous wastes presents certain advantages and disadvantages.

  • The main advantage is that lists make the hazardous waste identification easier for generators. On the other hand, hazardous waste lists simply can not include all hazardous wastes.

  • Another disadvantage is their lack of flexibility. Lists determine a waste as hazardous if it falls within a particular category or class.

  • The actual composition of the waste is not considered as long as the waste is listed. Thus, the lists can regulate some wastes that do not pose a significant health threat or a really hazardous waste may be not found in the lists [4].

  • Determination of hazardous waste by detecting the characteristics of the waste is another method which needs proper analyses to define the waste as a hazardous waste.

  • At first, all the hazardous characteristics including phytotoxicity, teratogenicity, bioaccumulation, mutagenicity are thought to be in characteristics of the hazardous waste, but because of the difficulties in testing protocols of these characteristics mentioned above EPA decided to use 4 common characteristics to identify the hazardous waste.

  • Although EPA introduces the test protocols for ignitability, corrosivity, reactivity and toxicity, there are still gaps which enable a hazardous waste to be determined as conventional waste.

  • The main gap is seen in toxicity testing, which only 43 of the toxic chemicals are subject to the TCLP test [5]. Thus, if a waste does not bear any of the 43 chemicals, the waste is not considered as hazardous, which may be a really hazardous waste.

  • The other example is ignitability which does not have a test method for non-liquid wastes. The gaps for the determination of the hazard potential of hazardous waste mixtures are also noticed and an index is prepared to serve as a guide for people who produce, store, transport, dispose, recycle and/or regulate hazardous waste [6].

  • Although lists and characteristics analyses are nearly the same in all countries, the differences in regulations make the determination subjective which creates a serious problem in management of these wastes.

  • In order to eliminate the subjectiveness of lists and characteristics tests, a quantitative determination system is stated in this study.

  • Overall Rating Value (ORV) calculates and quantifies a/any waste as regular (conventional) waste, non-regular (solid) waste or hazardous waste by using variables such as Ecological Effect (Ee) (ignitability, reactivity, corrosivity, toxicity), Combined Potential Risk (CPR) (carcinogenic effect, toxic characteristics, infectious characteristics, persistency), Physical Form (f), Listing (L) and Quantity (Q) of the hazardous waste.

Discarded Material




Can it be reused, recovered and/or recycled?




Is it defined in your wastewater, municipal solid waste and/or air pollution control regulations?



Hazardous Waste Determination

Check H.W.




Regular Waste

Has it hazard criteria?

Hazardous Waste







Non-Regular Waste

Rating System

To install the rating system formulation, following assumptions are postulated

  • 1. If a/any discarded material has been defined as a/any waste, the determination of the waste should be done such as wastewater, municipal solid waste and air emission. The term non-regular waste has been considered as intermediate waste which differentiates hazardous and conventional waste defined in regulations. If a waste is non-regular waste, next step is determination of hazardous waste. In Equation 1; the component D represents the boundary of the non-regular waste in the scale. Wastes such as hospital and radioactive wastes have been neglected in this inquiry because they have their own control regulations and these wastes are already identified as non-regular wastes.

  • 2. Listing methodology of the hazardous waste and their lists published in different countries cannot be neglected, thus the L component is additionally taken into account in order to determine hazardous waste.

  • 3. Ecological effects (Ee) includes primarily impacts from waste associated with their one or more hazard characteristics such as toxicity, ignitability, corrosivity and reactivity.

  • Physical forms of the waste are also rated according to behaviors of the waste in nature.

  • 4. Accumulative and synergistic effects and uncertain potential risks are included in combined potential risk (CPR) parameter.

  • Components of this parameter are human health toxicity, carcinogenetic effects, infectious risks, and persistency associated with biodegradability, solubility, and bioaccumulation.

  • Physical forms of the waste and exposure mode are also taken into account during evaluation of these risks.

  • 5. Four critical components explained above are considered as cumulative functions of Overall Rating Value (ORV) due to the higher values of these components, the higher ORV.

  • On the other hand, the amount of the waste is obviously a basic characteristic of the waste in this rating system, thus it should be a multiplier of the other components.

  • Rating system equation (Eq. 1) is composed of a cumulative-linear function coupled with 8 sub-equation run the points obtained from ranking tables for each parameter

Model Formulations

  • ORV = D+L+[Ee +( CPR ) x f]x Q (1)

  • Ee = I + C+ R + T (2)

  • I=in (3)

  • C=cn (4)

  • R=rn (5)

  • T=tn (6)

  • CRP = Cr + P + In + Pe (7)

  • P= pm (8)

  • Pe = (Bd )sl x ( Bac )-1 (9)

  • The aim of the proposed formulation is to quantify the hazard characteristics and to determine the hazardous wastes with easy and understandable numbers in a simple scale.

  • Calculated ORVs from Eq. (1) are matched with range of the hourglass scale in order to point whether the waste is regular, non-regular or hazardous waste.

  • D is the decision factor that differentiates defined regular waste from undefined wastes. The rating values for decision factor are listed in Table 1.

Table 1

  • L defines list value of the rating system. Knowing the source and composition of the waste is an important aspect for determination of the hazard characteristics of a waste and their listing accordingly.

  • USEPAs lists depend on both HW from specific source or non-specific source and discarded commercial chemical products. Therefore they are taken as the basis of the rating values listed in Table 2 to reflect the importance of the lists. However, the lists do not depend on the amount of the waste generate

Table 2

Rating Values for Hazardous Waste Lists

  • Equation 2 expresses the ecological effects Ee in terms of ignitability I, corrosivity C, reactivity R, and toxicity T.

  • In order to establish dimensionless data, all parameters are graded in rating value tables, thus the unit variability is eliminated. I is the corrected ignitability value obtained from Eq. (3) in which i is the dimensionless ignitability value of the rating system. Flash point (0C) used to grade i values should be determined using the test method specified in ASTM Standard D-93- 79 or ASTM Standard D-3278 [7, 8, 9]. C is the corrected corrosivity value obtained from Eq. (4) in which c is the dimensionless corrosivity value of the rating system.

  • The test method specified in EPA A600/4-79-020 is used to determine corrosivity value (mm/yr). Reactive substances which are extremely unstable and have a tendency to undergo violent chemical change or explode during stages of its management is available from descriptive, prose definition which EPA has publicized. However, a suitable test protocol is unavailable [7, 9, 10].

  • Referring to this definition reactivity is quantified in Eq 5 where r is the dimensionless reactivity value of the rating system.

  • It is necessary to include toxicity since leaching toxic constituents (of land disposed wastes) into the groundwater is one of the most significant dangers posed by hazardous wastes [11, 12].

  • Therefore, leaching procedures such as TCLP and EPT can be used for hazardous waste in solid and sludge form to obtain mobility of the organic and inorganic compounds [13].

  • Eq. 6 determines the corrected toxicity value T where t is the dimensionless toxicity value of the rating system. LC50 value obtained from bioassay test is used to grade the toxicity in the rating system.

  • The physical form correction factor n reflects the effect of the form of the waste on the intensity of the hazard criteria. The rating values of components of ecological effect, which also prevent unit variability, are shown in Table 3.


Rating Values for Components of Ecological Effects

  • 1 Specified by using the test method defined in ASTM standard D-3278

  • 2 Abrasion characteristics at 550 C specified by using the test specified in NACE (National Association of Corrosion Engineers) Standard TM-O1-69.

  • 3 There is no suitable test protocols for measuring reactivity.

  • 4 Extraction procedure (EP), toxicity characteristics (TC) and toxicity characteristic for leaching procedure (TCLP) methods described by EPA. [13]

  • Lq: Liquid, G: Gas, S: Sludge, SL: Slurry, SO: Solid

  • Combined potential risks CPR are represented as a function of toxicity risks for human health P, carcinogenic effect Cr, Infectious characteristics In, and Persistency Pe, in Eq (7).

  • The quantification of the toxic risk to human being is almost similar to the quantification of the environmental risk (LC50), and is given by LD50 which is the lethal dose to 50 percent of an exposed population of humans within a given time [14]. LD50 for quantifying the toxic characteristics P are tabulated in Table 4.

  • It is important to notice that only an individual material shall be considered in the combined potential risk if its existence in the waste is acknowledged. The constant m defines the effect of exposure mode on the intensity of the toxic characteristics. Main three exposure modes are considered as inhalation, oral intake and skin contact. The risks they pose can be graded respectively.

Table 4

Rating Values for Combined Potential Risks Eq (7)

  • *Exposure modes: I: Inhalation, OI:Oral Intake, IN: Ingestion, SC: Skin contact

  • 1 Health based risk specific doses for acutely toxic constituents.

  • 2 Risk specific levels for carcinogenic constituents as chronic toxicity reference levels.

  • 3 Animal carcass, animal feces, used sanitary pads, biotic chemical by products

  • 4 Bioaccumulation cannot be established experimentally, it may be predicted by its physicochemical properties and stability. Depend on the characteristics of individual substance and situation; biodegradability may be given as percent of its degradation. [14]

  • Evaluation method of the carcinogenity of the hazardous wastes is far from a quantitative approach.

  • The classification for the existence is based on the predicted occurrence of cancer for instance in one person from hundred thousand (10-5) [9, 14]. Values used in the rating system for Cr according to this classification are given in Table 4.

  • The infectious characteristics of a hazardous waste depend upon criteria of being contaminated with relatively high fractions of disease causing material or an accumulated disease causing waste.

  • Medical and hospital wastes are not covered within the context of hazardous waste management but tracked under special acts and managed accordingly.

  • The infectious risk has to be foreordained with the sources of waste.

  • Dimensionless infectious risk value of the rating system, In, is involved in rating system and listed in Table 4 for other than conventionally managed wastes that need special care due to their infectious characteristic.

  • Persistency is a function of biodegradability, bioaccumulation, and the solubility characteristics of which the persistency rating equation Eq (9) consists.

  • The ability of the degradation, Bd, of a chemical material within the environment or living cell is generally directly proportional to the solubility. This effect is reflected within Eq (9) with the exponential expression of dimensionless solubility value of the rating system Sl.

  • The possessed risk in the non-biodegradable material is their adverse effect on human health when reached either trough food chain or water. The living organisms in water can only degrade soluble materials; otherwise, the prevailing case will be the accumulation of substances. Quantification of bioaccumulation is not possible [14].

Depending on descriptive classification of bioaccumulation characteristic of a matter, dimensionless bioaccumulation value of the rating system Bac, Bd and Sl values are also given in Table 5.

Table 5

Evaluation of Persistency Values Eq(9)

  • The physical form of the waste should be a function for the evaluation of the combined potential risk because of fate of the waste in the environment is relevant to its physical form. For instance, different risk assessments should be made for waste in solid form or gas form.

  • The physical state factor f is determined and placed in equation with the rating values summarized in Table 6 in order to reflect the afore statement.

Table 6

Rating Values for Physical Form

  • The multiplier Q, which is quantity rating value, is set in consideration of quantity of the waste and its recurrent rate of arising.

  • The handling and disposal of a few hundred kilograms of a particular waste may demand totally different solution to the disposal of similar material arising on a regular basis in quantities, which may be orders of magnitude greater or smaller.

  • Selected Q value from Table 7 is the last asset to put in Eq (1) for the evaluation of ORV.

Table 7

Rating values for quantity

Scaling of Rating System

Projection of the ORVs, which are obtained from the model equations for hazardous waste determination, is considered with an hourglass scale that shown in Figure 2.

Regular Waste


Non-regular Waste


Hazardous Waste

  • While upper side of the hourglass represents the regular wastes, lower part represents both non-regular and hazardous waste. Bottleneck points the zero level which separates regular waste from non-regular waste.

  • While 50 point level is upper limit for non-regular waste decision, it is minimum value for hazardous waste determination. These levels have been interpolated by minimum and maximum values of Eq. (1)s components. Interval of zero to 50 determines a waste as a non-regular waste. In this situation, a waste is neither hazardous nor regular. Besides hazardous waste lists are prepared associated with this non-regular waste definition in the regulations. Every additional value such as L, Ee, and CPR to this level makes the wastes hazardous waste. Calculated ORVs with Eq. (1) and their remarks for 16 waste samples are summarized in Table 8.

  • Results and Discussion

  • The ORV values have been obtained in Table 8 for seventeen real samples in detailed and they can be interpreted as follows:

  • Although first four samples have no Ee and CPR values controlled by referred test methods, neither regular nor hazardous waste lists include these wastes. Thus, they are determined as non-regular waste.

  • Foundry sand and metal slag may be landfilled in situ or on site if it cannot be reused such as road construction. Huge amount of fly ash sludge should be disposed to controlled landfill area after solidification. If plastic and rubber scraps cannot be recycled, their air pollution controlled incineration is recommended because of their high calorific value.

Table 8

Application of the rating system to the waste samples

  • Samples numbered as 5, 7, and 9 in sludge form have high toxic and corrosive characteristics in terms of Ee values according to TCLP test method and acidic pH (pH<2).

  • Their Ee components have correlated values which are 120, 120, and 167 respectively and relatively increasing CPR values causing increasing ORV values.

  • Ultimate disposal is recommended after detoxification and corrosivity control for these wastes.

  • Sample 6 named boron oils and lubricants as spent hazardous materials from foundry has low Ee but high CPR values because of its persistency and non-biodegradability. In spite of high flash point of this sample, it can be assumed as flammable material due to high calocorrosivity control for these wastes.

  • calorific values of organic constituents. Thus, if floatation isnt a proper treatment alternative, incineration should be considered for solution of its ultimate disposal.

  • Samples numbered as 11 and 14 in sludge form have nearly same Ee and CPR values based on mainly toxic and reactive hazard criteria because there are cyanide and other reactive materials in their composition. Despite nearly same Ee and CPR values, differences between ORVs can be explained by big difference between amounts (Q) of them.

  • Thus, a very careful handling is required for management these wastes such as dewatering, detoxification, solidification/stabilization, and ultimate disposal to spent mines or hazardous waste sites.

  • In samples numbered as 8, 10, 12, 13, common hazard criteria is toxicity (T) caused by chromium, sulfide, organic and inorganic pigments and solvents concentrated in treatment sludges.

  • High LC50 values and toxic characteristics (TC) are determined by TCLP and EPT procedures for both individual material and overall leached water.

  • Concentrations of these materials such as chromium and some solvents increase the CPR value when they are assessed with TLV and TWA limits. Direct solidification/stabilization or detoxification in their leachate and then disposal methodologies can be recommended for these wastes.

  • Discarded chemicals from university laboratories (sample 15) show a mixed waste characteristic having all hazard criteria (I, T, C, R).

  • Therefore, it has high Ee value. Incineration has been applied for this waste in hazardous waste site after carefully sorting, storing, and transportation to the site.

  • Acrylonitrile spills during Marmara Earthquake (sample 16) has been assessed as accident of a hazardous material.

  • Significant amount of this spilled commercial material threats the environment especially soil and water and human health as a hazardous waste. Ee and CPR values are very high due to its high hazardous characteristics.

  • Soil remediation and clean up procedures should be applied in contaminated area.

  • 2, 4 D Acid production waste (sample 17) contains a lot of hazardous constituents such as cyclohexanone, gasoline, alcohols, 2, 4 D and PCBs as liquid form of hazardous waste.

  • Besides, it is published as a hazardous waste in more than one list (USEPA K, F, U). It has also maximum Ee and CPR values because of its obvious hazardous specifications such as toxicity and reactivity.

  • Management alternatives for this waste can be considered as chemical treatment by adsorption, extraction, and oxidation or its direct incineration in air pollution controlled incinerator on site.

  • Breakpoints or determination levels in hourglass scale have been obtained with investigation of real wastes and according to their values of hazard criteria.

  • However, neither high nor low ORVs represent a/any hazardous waste as important, significant or moderate but they show that these are exactly regular, non-regular or hazardous waste.

  • On the other hand, a waste which has a higher ORV than another one has more attention required for its management.

  • Conclusions

  • The ORV and hourglass scale proposed here is a simple solution of the problem related to whether a waste hazardous or not. This rating system is not only to determine waste type but also helps to listing procedures showing management alternatives according to main components of the model i.e. Ee and CPR. For instance, if there is a high Ee value caused by toxicity and/or, firstly waste should be detoxified and/or neutralized as a management strategy and then it can be disposed. Similarly, incineration should be first management alternative for an ignitable waste that has a low flash point. On the other hand, due to CPR value depends on estimation of the long term effects, risk minimization methodology should be applied for management of the waste. CPR value is basically used for determination of the waste.

  • The proposed rating system is open for upgrading with modification into a refined version eliminating subjective procedures used in law or regulations. In this case, this system may be recommended to rewrite subjective and problematic hazardous waste regulations and lists.

  • Nomenclature

  • ORV: Overall Rating Value

  • Ee: Ecological Effect

  • CPR: Combined Potential Risk

  • L: Listing Value

  • D: Decision Factor

  • f: Physical State Factor

  • Q: Quantity Rating Value

  • TCLP: Toxicity Characteristic Leaching Procedure

  • I: Corrected Ignitibility Value

  • C: Corrected Corrosivity Value

  • R: Corrected Reactivity Value

  • T: Corrected Toxicity Value

  • i: Dimensionless Ignitibility Value

  • c: Dimensionless Corrosivity Value

  • r: Dimensionless Reactivity Value

  • t: Dimensionless Toxicity Value

  • Cr: Dimensionless Carcinogenic Effect Value

  • P: Corrected Toxic Risks for Human Health Value

  • In: Dimensionless Infectious Characteristics Value

  • Pe: Persistency Value

  • p: Dimensionless Toxic Risks for Human Health Value

  • Bd: Dimensionless The Ability of Degradation Value

  • Sl: Dimensionless Solubility Value

  • Bac: Dimensionless Bioaccumulation Value

  • HW: Hazardous Waste

  • EPT: Extraction Procedure Toxicity

  • n: Correction Factor Depend on Waste Form

  • LC50: Lethal Concentration to 50% of an Exposed Population of Fishes within a Given Time

  • Lq: Liquid

  • G: Gaseous

  • S: Sludge

  • SL: Slurry

  • SO: Solid

  • EP: Extraction Procedure

  • TC: Toxic Characteristics

  • LD50: Lethal Dose to 50% of an Exposed Population of Humans within a Given Time

  • m: Exposure Mode

  • I: Inhalation

  • OI: Oral Intake

  • IN: Ingestion

  • SC: Skin Contact

  • NRW: Non-Regular Waste

  • TLV: Threshold Limit Value

  • TLW: Time Weighted Average

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