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Urbanization, development of economy, increasing population and improved living standards and lifestyle have caused a sharp growth in waste. Inappropriate or inefficient waste disposal techniques can cause serious air, soil, and groundwater pollution, which subsequently can negatively affect the urban environment and threaten the health of residents. The goal of waste management is to move to a circular economy in which waste does not exist. If there is no possible way to reduce or reuse waste, the best solution is recycling it. Recycling brings abundant benefits on the economic and ecological levels levels, and helps reduce overall human health risk of adverse impacts. Recycling of the waste-cables which contain PVC and copper replaces the production of virgin PVC and mining of copper from copper ore, it reduces landfill solid waste pressures, saves energy and water sources, reduces emissions to environment, and also reduces negative impacts from improperly dispose of waste, etc. This paper presents an overview of recycling techniques for the waste-cables containing copper as a core and polyvinyl chloride as an insulating layer or sheath. It also lists advantages and disadvantages of these techniques and importance of recycling this type of waste.
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2021, Volume 29, Number 48 DOI 10.2478/rput-2021-0001
Received 28 April 2021, Accepted 15 May 2021, Published 20 July 2021
Urbanization, development of economy, increasing population and improved living
standards and lifestyle have caused a sharp growth in waste. Inappropriate or inefficient waste
disposal techniques can cause serious air, soil, and groundwater pollution, which subsequently
can negatively affect the urban environment and threaten the health of residents. The goal of
waste management is to move to a circular economy in which waste does not exist. If there is
no possible way to reduce or reuse waste, the best solution is recycling it. Recycling brings
abundant benefits on the economic and ecological levels levels, and helps reduce overall human
health risk of adverse impacts. Recycling of the waste-cables which contain PVC and copper
replaces the production of virgin PVC and mining of copper from copper ore, it reduces landfill
solid waste pressures, saves energy and water sources, reduces emissions to environment, and
also reduces negative impacts from improperly dispose of waste, etc. This paper presents an
overview of recycling techniques for the waste-cables containing copper as a core and polyvinyl
chloride as an insulating layer or sheath. It also lists advantages and disadvantages of these
techniques and importance of recycling this type of waste.
Waste-cables, recycling, copper, PVC, circular economy
Rapid urbanization, population and economic growth are related to increased production
of waste. The fact that we do not dispose or do not recycle it correctly, causes the release of
large amounts of waste to the environment [1, 2]. Every year, we dump a massive 2.12 billion
tons of waste on the planet. This stunning amount of waste is partly because 99 % of the things
we buy is trashed within six months. Dumping waste and improper waste management have
negative consequences on the planet, such as (i) pollution of soil (waste can leak hazardous
chemicals into the soil and, from there, into our food) [3, 4], (ii) air pollution (the trash that is
dumped in landfills releases methane gas; accidental fires of wastes at landfills release toxic
substances into the air, including extremely poisoning dioxin) [2, 5], (iii) pollution of oceans
(13 million tons of plastics end up in the world’s oceans each year, if we keep throwing out
plastics in the oceans, by 2050, there will be more plastics than fish in the sea; the plastic waste
affects fish, seals, turtles, whales, and many other aquatic animals, as scientists have found
many plastic fragments in over a thousand species that cannot distinguish between what is or is
not food) [2, 6, 7], and (iv) pollution of groundwater (280 billion tons of groundwater is being
polluted every year that’s 9,000 tons every second) [8, 9]. Generally, the amount of waste
generated affects the environment in multiple ways: it is contributing to the worsening climate
crisis, it has a negative impact on wildlife and the natural environment, and is detrimental to
our very own public health [2].
Households use a wide variety of electrical and electronic device (e.g. vacuum cleaners,
washing machines, refrigerators, the gadgets, mobile phones, computers, televisions), while
each of those products contain cables [10]. With the rapid development of the power and
information technology industries, the production and application of cables have expanded [11].
Electrical wiring in a block of flats, but also in old family houses, today no longer meets current
safety standards, and it is therefore necessary to replace it by a new one [12]. There are several
causes why a large number of waste-cables is generated all around the world every year. About
70,000 tons of waste-cables containing copper and polyvinyl chloride (PVC) resources (or other
materials) are disposed in landfills every year, and create local environmental burdens [13].
Therefore, the recycling and the reutilization of waste-cables has become an important topic
not only in the field of environment protection [11, 13, 14].
Producing, consuming, and throwing products away is starting to affect our planet and our
way of life. To ensure enough food, water, and prosperity for the years to come, we need to
change it. We need to switch from a linear to a circular economy [15, 16].
Cables are components that are used in the sectors of transport, construction,
communication, and consumer goods [11, 13]. Cables can be divided into five major categories,
including magnetic wires, uninsulated wires, electrical wires and cables, power cables and
communication cables, according to their structure, manufacturing process, function and usage
characteristics. Depending on the final application of cable, cables can have different
configurations, always basing their design on national and international regulations. Electric
cables are measured in volts and, depending on these, they can be categorized into: low voltage
cables (divided: up to 750 V; up to 1,000 V, also called 0.6/1 kV; used for industrial power
installations in various fields such as industry, public installations, infrastructures, etc.),
medium voltage cables (from 1 kV to 36 kV; used to distribute electricity from electrical
substations to transformer stations), high voltage cables (from 36 kV; used to transport
electricity from the generating plants to the electrical substations). Depending of their use, the
low voltage cables can be divided into cables for electric panels, power cables, armored cables,
rubber cables, halogen-free cables, fire resistant cables, control cables, instrumentation cables,
solar cables, special cables, and aluminum cables [17]. Depending on diameter of cables, they
can be divided into thin (mm-order-diameter) and thick (cm-order-diameter) cables [13, 18].
Generally, the cable consists of an electric conductor (a conductive metal core such as
copper, aluminum), insulation, auxiliary elements (to protect the cable and guarantee its
longevity) and outer sheath (covers all the mentioned materials, while protecting them from the
outside) [13, 17]. The insulating layers are classified into two groups thermoplastic (the most
common are: PVC, polyolefins, linear polyethylene, polyurethane) and thermoset (the most
common are: ethylene propylene, crosslinked polyethylene XLPE, ethyl vinyl acetate,
silicone, neoprene, natural rubber). In some cases, a cable may has metal shields called
armored cable (armors means mechanical protection that protects the cable from possible
external aggressions: animals, physical damage, etc.; the cable can withstand higher stresses,
which can make it suitable for direct burial, or allows it to be used in external underground and
underwater projects) [17, 19].
The following Table lists selected cable types, their composition and approximate weight.
Table 1 Construction of selected types of cables and their weight
Annealed copper, PVC insulation
Cable weight (approx.) [kg/km] 21 3,987
Annealed copper, PVC insulation, PVC
inner sheath, PVC outer sheath
Cable weight (approx.) [kg/km] 115 1,256
Conductor, Conductor shield, Insulation,
Insulation shield, Metallic shield, Filler,
Binding tape, Oversheath, Insulation:
Cable weight (approx.) [kg/km] 1,705 13,010
Conductor, Fire barrier (mica tape),
Insulation, Inner sheath, Armour,
Binding tape, Outer sheath
Cable weight (approx.) [kg/km] 274 8,440
Conductor, Cross-linked PE insulation,
PVC inner sheath, Aluminum wire
armour, Binding tape, PVC sheath
Cable weight (approx.) [kg/km] 136 7,344
Conductor, Conductor shield, Insulation,
Insulation shield, Copper tape, Bedding,
Aluminum tape, Binding tape, PE sheath,
Insulation: XLPE
Cable weight (approx.) [kg/km] 800 13,505
PE or PP insulated conductor, Non-
hygroscopic tape, Aluminium shield, PE
sheath, Support messenger
Cable weight (approx.) [kg/km] 250 1,720
Note: weight of cable depending on diameter of conductor [mm], number of pairs or cable type
There are a lot of types of cables of a different construction. Construction of cables depends
on the type of cables and the environments of their utilisation (such as surrounding temperature,
atmospheric humidity, altitude, water presence, presence of corrosive substances or stains,
presence of vegetation or mold, seismic influences, air flow, etc.). For example, ELKOND
HHK, a. s. Company, Slovakia, manufactured this kind of cables: Power cables with reaction
to fire (6 types of cables), Control cables with reaction to fire (8 types), Communication cables
(10 types), Control cables LF (4 types), Special conductors (5 types), Communication cables
and conductors (6 types), Control cables (5 types), Power cables and conductors (flexible)
(4 types), Power cables and conductors (for fixed installation) (2 types), Copper products (as
copper wires, stranded copper wires, special copper rope), Power cables for fire protection of
buildings in Czech Republic (6 types). Each type of cable has its basic characteristics (electric,
fire-fighting) and construction, and can be manufactured in different varieties depending on
number of cores × nominal cross-section [n × mm2] [118].
By [119], for all cable types, the conductor makes up between 52 and 70 % of the weight
of the total cable for a given linear length of the cable. The percentage mass of insulation ranges
from 10 to 21 % of the cables, and jacketing (sheath) ranges from 19 to 34 %. Separators (also
referred to as spacers or crosswebs) or other components constitute between 2 and 4 % [119].
This statement probably applies to selected types of cables. This is confirmed, for example, by
the % results of 1-CXKH-V 3x1.5 P60-R cable composition (further referred to as CXKH) and
N2XH-J 3x1.5 RE (further referred to as N2XH) [120], which are listed in Table 1. These
indicate different % shares of metal core, insulation and other components. This is also
confirmed by the results of other authors. According to [121], the multiwire copper cable
contains 25.4 % of copper cords, 28.7 % of tinned copper braids (28.3 % of Cu, 0.324 % of Sn),
43.2 % of PVC insulation (22.1 % of PVC, 11.5 % of DEHP, 9.55 % of filler CaCO3), 1.57 %
of polyester foil and 1.19 % of cotton cords. According to [122], cable contains 26.9 %
of copper, 14 % of insulation and 56.1 % of sheath.
Table 2 Basic parameters of the CXKH and N2XH cables [120]
In this article, all products which consist of at least two layers, namely the conductor (e.g.
copper, aluminum) and the insulating layer or sheath (made of plastic material), are considered
as cables.
The common copper-containing cables typically consist of a conductive copper core, an
insulating layer (PVC, polyethylene PE), and a flame-retardant protection layer [11, 13]. The
purpose of the waste-cables recycling is to separate metals from insulating layer, sheath or
another layer, and obtain high-purity materials. The waste-cables recycling enterprises use
semi-mechanized or mechanized treatment techniques [11].
Copper is a versatile base metal that is very vital for different sectors and used in a variety
of applications, e.g. for making pipes, electrical components, electrical cables and also for
building constructions, production of industrial machinery, transportation vehicles, in
architecture; it plays a key role in the worldwide information and communication technologies
[20, 21, 22]. It is the best conductor of electricity after silver, as it encounters much less
resistance compared with other commonly used metals (is used as standard benchmark to which
other conductors are compared). It is the third most important industrial metal, just after iron
and aluminum, in terms of consumption, due to its resistance to corrosion and its thermal and
electrical conductivity. Also, is one of the most recycled metals [13, 21, 22]. Virtually all
products made of copper can be recycled, as recycled copper loses none of its chemical or
physical properties [22]. In 2018, an estimated 24.5 million metric tons of copper were
consumed worldwide [20].
PVC is one of the most used thermoplastic material in respect to the worldwide polymer
consumption. It has in fact several intrinsic characteristics which make it the ideal choice for a
range of different applications can be processed into a wide variety of short-life products
(such as packaging materials used in food, cleansing materials, textile, and medical devices)
and also long-life products (such as pipes, window frames, floors coverings) [23, 24]. PVC can
be also used as insulation and/or sheathing for production of any type of the electric and data
transmission cables [25]. Among the most interesting properties of PVC materials are
processability, resistance to temperature, resistance to hydrocarbons, self-extinguish properties,
fire resistance, insulating properties, flexibility, transparency, recyclability and it is light and
easy to reuse [25, 26]. The properties of PVC can be significantly influenced by using a
combination of plasticizers, fillers, stabilizers and other additives [25, 27]. For example,
plasticizers make PVC soft and bendable, which is an essential characteristic to produce cables
and to ensure their durability for decades (PVC cables can last up to 80 years under normal
conditions of use) [24, 28]. Different plastics are used as insulation and sheathing for electric
cables, as well as the sheathing for telecommunication cables. Among these, the PVC is most-
widely used, because it is able to ensure the best cost/performance ratio, high sustainability and
recyclability [25]. In 2016, the consumption volume of PVC reached 42,931.1 thousand tons,
and it is forecast that the volume will increase up to 55,715 thousand tons in 2022 [29]. In 2017,
the wires and cables made of PVC accounted for a seven percent of the total consumption of
PVC worldwide [30].
Nowadays, a lot of simple and convenient techniques are available for recycling thick
waste-cables (they are easily stripped or crushed into small scrap nuggets and then sorted),
while multi-step techniques are used to recycle thin waste-cables [13, 31]. These multi-step
techniques typically involve (i) mechanical treatment technology (such as stripping technology,
crushing technology), ultrasonic separation, hot water treatment technology, cryogenic
technology or high-pressure water jet technology combined with a technology for separation of
copper and plastic particles, (ii) chemical technology (such as dissolution and cementation,
chemical- or bio-leaching, or chloride volatilization), and (iii) energy/heat recovery processes
(such as incineration and thermal decomposition) [13, 14, 31]. Separation can be performed
through (i) gravity separation techniques (a gravity separator can use a combination of air,
vibration and separation, based on density/size/shape difference [101, 102], such as air gravity
separation [103], jigging separation, shaking table separation [104], etc.), (ii) electrostatic
separation, and (iii) flotation, etc.
Mechanical treatment technology is widely used for waste-cables recycling. In the early
stage, this technology requires manual rough sorting of waste-cables. Obtained copper core and
plastic material are separately recycled. The most common used mechanical treatment
technologies (Figure 1) include:
Stripping technology: The working principle of stripping machine is relatively simple,
but could be very time consuming, depending on the type of equipment used and the
amount of scrap. The machine is mainly driven by a stepping motor and wheel-clamped
cable movement [124]. The specific process is as follows: the cables are collected,
sorted by diameters, and treated by a stripping machine (it removes the insulation from
the cable, leaving a pure core). The stripping machine operates by stripping the
insulation by a blade or a knife, while an operator feeds the cable into a feed port, and
an electric motor pulls the wire through. The operator then peels the cable manually, or
the insulation falls off, depending on the thickness of the cable and/or conditions [125,
126]. This type of machine is well-automated, but the application scale is deeply
confined; it can be only applied to stripping a particular cable of certain diameter.
Therefore, researchers and waste-cables enterprises have made significant improvement
to the traditional wire strippers, by rendering the stripping technology more efficient
and more practical [11].
Crushing technology: Waste-cables are crushed into particles of particular size after
passing the crushers and then separated (with sorting equipment) into a plastic material
and a copper rice. The equipment (containing the crushing and sorting units) used in
this type of treatment is commonly known as a “copper rice machine” [11].
Figure 1 Mechanical treatment technology of cables (stripping and crushing process).
Adapted from [92-96].
Capacity of the waste cable processing equipment varies (e.g. stripping machine:
100 300 kg/days [97], 200 1000 kg/day [98], crushing machine: 100 1000 kg/h [99, 100])
and depends on several factors (e.g. degree of process automation, type of equipment, type of
cable-single-core or multi-core, cable construction, diameter of cable, material used in cable,
recycling purity of metal).
Figure 2 shows the process flow of waste cable treatment for one type of a copper rice
machine. Based on the size and type of the treated waste-cables, the separation processes of the
copper rice machine vary (e.g. the two-stage crushing + pneumatic separation, wet separation
or electrostatic separation, three-stage crushing + two-stage separation) [11].
Figure 2 The process flow of waste-cable treatment for one type of copper rice machine.
Adapted from [11].
In the cryogenic shredding technology (also as freezing process) shown in Figure 3, cables
are treated with appropriate refrigerant (e.g. liquid nitrogen is an inert substance) to make the
plastic material more brittle, making it easy to crush, while the conductive copper core retains
its strength. This process is suitable mainly for the waste-cables that cannot be easy to crush at
the room temperature (cables containing e.g. polypropylene, low-density polyethylene, high-
density polyethylene, ultra-high molecular weight polyethylene) [11, 32, 33, 34, 35].
Figure 3 The process flow of waste-cable treatment through liquid nitrogen freezing technology.
Adapted from [11].
In the high-pressure water jet cutting technology, the waste-cables move uniformly relative
to the high-pressure water jet, and the huge energy produced by the water jet causes a pressure
transient on the surface of the plastic sheath, resulting in its tearing in a very short time. This
technique uses cold cutting and does not produce thermal deformation in the processing of
waste-cables [11, 36].
A hot water separation technology can be used to recover metal and insulating material
from cable-waste. Based on the differences in the thermal expansion coefficient of insulating
material and copper, the cables are cut into a suitable length (with no need to grind the cable
into smaller pieces) and placed into a blender with hot water. By controlling the water
temperature, blending speed and cutting length, complete separation can be achieved [37].
The ultrasonic separation recycling uses the cavitation phenomenon induced by ultrasonic
waves that goes through the water. The ultrasound cavitation effect causes the waste-cables
immersed in water to sway and vibrate, to achieve the separation of the copper core and plastic
sheath [38].
The separation of copper and plastics can be performed by mechanical/physical methods.
The differences on the physical characteristics of materials in non-homogeneous compounds
(such as magnetism, electric conductivity, density, etc.) are the bases of the mechanical/physical
separation of them (e.g. magnetic separation, conductivity-based separation, sieving or density-
based separation). Magnetic separation is widely used for the recovery of ferromagnetic metals
from non-ferrous metals and other non-magnetic materials [39]. Electric conductivity-based
separation is used to separate materials (metals, non-metals) of different electric conductivity
(or resistivity) [39, 40, 41]. There are three typical electric conductivity-based separation
techniques: (i) Eddy current separation, (ii) Corona electrostatic separation, and (iii)
Triboelectric separation [39, 42, 43]. The gravity separation (density-based separation) has
large energy consumption and low efficiency, and therefore, over the last years, electrostatic
separation technology has been researched and has compensated for the deficiency of gravity
separation [11]. There are studies [43, 44, 45] that focus on estimating the optimal conditions
of the process variables (e.g. electric field, splitter position, relative humidity) on the separation
efficiency. One of serious problems is, if the waste contains multicomponent materials, because
the presence of impurities greatly increases. The difficulty of their recycling leads to reduction
of the quality of the obtained products. Therefore, accurate and efficient separation is an
important pretreatment step in their subsequent recycling [14].
Some types of waste-cables are difficult to recycle by using the above-mentioned
techniques, and therefore chemical treatment technology have been proposed. The traditional
chemical treatment technology is a method in which the solid materials are immersed in a series
of leaching solutions to obtain the metal; the target metal products are then obtained through
the displacement, crystallization, extraction, or electrolysis of the leaching solution [11]. The
technologies for the treatment of waste-cables include the dissolution and cementation or
precipitation [14, 46], chemical leaching, and bio-leaching. The majority of these technologies
focus on the recovery of copper without PVC treatment [14]. Given the waste-cables have a
very high copper content, there is a high consumption of leaching solutions. Therefore, the
technology is not suitable for the treatment in large numbers of waste-cables [11]. This
technology can be used as secondary technology treatment if the plastic materials obtained from
the mechanical/physical separation still contains some copper (low-copper-content waste-
cables) [47, 48]. According to [11], chemical technology is to treat waste-cables by the use of
salt solution or organic solvents which dissolve the plastic material, but do not react with the
copper cores. Also, other specific methods can be used for recycling pure PVC and copper from
the waste-cables (e.g. PVC swelling and mechanical agitation in hydrophobic organic solvent
mixed with water, PVC swelling and rod milling, technique involving PVC embrittlement via
plasticizer extraction and crushing by ball milling) [13, 14, 31, 49].
The following Figure shows the flowchart of metals recovery from the mixture of the
electronic waste and sulphidic tailings.
Figure 4 The flowchart of metals recovery from a mixture of the electronic waste and sulphidic
tailings. Adapted from [123].
Energy/heat recovery processes include incineration and thermal decomposition. In the
beginnings of waste-cables recycling, the main process was incineration. This process is simple
(the plastic material of waste-cables is burned directly in an incinerator to recycle copper) and
suitable for treating waste-cables of various specifications [13, 50]. Given the incineration
problems (such as oxidation of copper and the formation of toxic gases), this process is
eliminated in many countries. The problems can be solved by performing the pyrolysis (at 500
900 °C) in the absence of oxygen [11, 13, 14] or by other methods (e. g., using the induction
heating voltage method or using high temperature steam gasification) [11, 51]. A pyrolytic gas
(fuel gas), fuel oil, and carbon black are obtained from pyrolysis of waste-cables sheaths, and
copper remains in the metallic state [11, 14].
The various types of metals and plastics are used for producing cables, and this fact can
pose a problem during recycling. Therefore, the recycling process should be proposed as a
treatment and separation of all types of materials as mixture (regardless of the type or the
thickness of the insulating layer or metal core). The first step of separation is to divide materials
into non-metals and metals, and then separate based on the type (PVC, PE, rubber or copper,
aluminum). For example, aluminum and copper can be sorted using a roll-type electrostatic
separator equipped with a reversed-S-shaped-plate high-voltage electrode at very high degrees
of purity [52], density-based separation, sorting by using eddy current separation [53], or high-
resolution optical sorting system [54]. For separation of different plastics for example
triboelectrostatic separation can be used [55, 56], as well as selective flotation separation [57,
58], or laser-induced plasma spectroscopy [59, 60], etc. There is need to use a combination of
various treatment technologies to obtain materials with very high purity.
About 30 entities in the Slovak Republic deal with recovery of waste from ferrous and non-
ferrous metals, including waste-cables treatment. Waste from ferrous and non-ferrous metals
are a commodity with the network of collection and repurchase centers, which can be
characterized as over dimensioned in many locations [61]. Many different technologies of
waste-cables treatment are used such as crushing and subsequent separation of material
components by means of a machine with a vibrating plate [62]; mechanical grinding and
granulation with subsequent separation of materials based on fluid separation [63]; or crushing
to the required fraction and subsequent separation by air flow [64].
Each techniques of waste-cables recycling has its own advantages, disadvantages, and its
own scope of application. Although the process for each waste-cables recycling technology
vary, the aim is the same to separate the copper core and plastic sheath.
The mechanical treatment technology is a simple low-cost process that is the most widely
used. The process has also disadvantages such as dust and noise pollution; the application scale
can be deeply confined (e.g. only applies to the stripping for a particular cable with certain
diameter); the crushing can requires initial manual cutting and lead to severe human resource
waste and extremely low efficiency; in the operation of the copper rice machine, the friction
between the equipment and waste-cables produces high temperature and heat, resulting in
wearing and even operational failure of the copper rice machine. Therefore, the development
of high efficiency and low consumption waste-cables cutting, and sorting technology and
equipment is very significant for improving this industry’s efficiency and working
conditions [11]. The cryogenic shredding technology (the utilization of liquid nitrogen) has
undoubtedly numerous advantages in the treatment of waste cables, such as readily available,
easy handling, low technical input, easy control, good heat transition, low dust and noise
pollution, low crushing force and the fact that heat-sensitive materials will not oxidize and
deteriorate (no loss of copper, high-quality plastic recycling). The main disadvantage is the high
operation costs caused by using liquid nitrogen. Therefore, it is imperative to develop efficient
refrigeration technology and optimize the process flow of cryogenic grinding to decrease the
cost [11, 32]. The ultrasonic separation recycling and the high-pressure water jet cutting are a
green recycling technologies that does not change the physical and chemical properties of
copper and plastic, and have excellent environmental benefits (such as high recovery rate, low
energy consumption, etc.) [11, 37, 38]. The main problem of these treatment technologies is
that processing scale is small and its difficult to achieve industrialization. Adaptability of
chemical treatment technology is low; the required chemical regents depend on the composition
of the plastic material in waste-cables; the treatment process consumes a large quantity of
solvents and thus can easily lead to secondary pollution. Because of these concerns, further
improvements are imperative for the industrialization of chemical methods. The advantage of
this technology is obtaining high degree of plastic resources [11]. Incineration is a simple
treatment technology, but has a lot of disadvantages such as that the surface of the copper core
after treatment is severely oxidized [11, 13, 14], largely decreasing the copper’s purity (recycled
copper cannot be directly used for processing copper products and must go through smelting
and electrolysis which increases the processing steps and costs of process) [11, 105]. In
addition, the oxidized copper components of cables become part of toxic metal compound in
the bottom and fly ashes (e.g. as copper metal, copper oxides, mixed oxides [107], copper
sulfides [108]; copper in oxidation states 0, +I and +II [107]; CuO [109], Cu2O, (Co,Cu)2O,
(Cu,Zn)O, (Mg,Fe,Zn)O, (Mn,Fe,Cr,Ni,Cu,Zn)2(Al,Ti,Fe)O4, CuS, (Cu,Fe)S, FexCuyS [108],
CuCl2·3Cu(OH)2, CuCl, Cu(OH)2. CuCl2·3Cu(OH)2 [110], etc.), which prevent their use as
metal materials [14]. Given that the main components of the plastic sheath in waste-cables are
thermoplastics (such as PVC, PE) and flame retardants, the smoke and gas produced from the
incineration process contain toxic gas (contains e. g. polycyclic aromatic hydrocarbons,
polychlorodibenzo-p-dioxins, polychlorodibenzo-furans, chlorobenzenes, chlorophenols,
chlorobiphenyls) and dust [11, 13, 14, 50]. This could be especially hazardous when the process
is uncontrolled. Illegal recycling, open burning at landfills or accidental fires can causing severe
deterioration to the environment and harm to human health [50]. The incineration in controlled
atmosphere incinerators should be safe because there are effective flue gas cleaning systems
utilized [106]. Developing others new environmentally friendly incineration technologies to
improve existing technologies is still a must. By using a thermal recovery process to treat waste-
cables, maximal recycling and harmless disposal can be achieved [11]. Pyrolysis of waste
plastics containing PVC could provide alternatives that replace natural gas and propane;
however, pyrolysis is associated with high-energy costs required for heating [13].
For effective treatment of waste-cables is very important to choose suitable technology.
The goal is obtaining the highest possible purity of the separated metals and plastics, and the
copper content in the separated plastic should be as close to 0% as possible. The best choice
would be the technology that can treat various type of cables regardless of the type of cable,
material of core or sheath, diameters, etc. The technology of treatment should be effective, fully
automatized, environmentally friendly, and economically advantageous.
The waste-cables are generated in more ways, such as during manufacturing process of
cables (cables with insulating material defects), owing to the end-of-life of cables (obtain during
repair buildings and electro-installation) or end-of-life of electric and electronic equipment.
These waste-cables are a big part of problem and create a serious waste management issue [14,
35]. Managing waste in a more efficient manner is the first step towards circular economy [65].
The circular economy is rethinking production and consumption patterns to limit waste and
thus optimize the use of resources. The old economic model of extracting, producing,
consuming, and disposing can no longer apply if we want to protect our planet. To effectively
reduce its disastrous environmental consequences requires a change in the economy. Making
the circular economy therefore means repairing, recycling, and reusing instead of throwing
away, but also understanding the limits of natural resources [66]. Reusing, redistributing and/or
remanufacturing strategies are the preferred approaches in a circular economy, as they are based
on parts durability [67, 68]. Caring for and preserving the value of product components
increases corporate economic resilience, while diminishing external market risks [68].
However, the recycling of materials from waste is necessary for the circular economy due “to
close the loop” [69].
The priority should be to discourage non-essential production and unnecessary
consumption or use [70]. Next, very important step is increasing of recycling, because generally
recycling rates globally are low. The circular economy is developing but the ocial model is
not yet in place [66]. Transitioning an economic model from linear to circular requires the
involvement and commitment of several stakeholders, such as producers, consumers, and
policymakers [71].
The most valuable component of the waste-cables that should be recycled is non-ferrous
metals (e.g. copper, aluminum; the plastic insulated waste-cables contains 4090 wt. % of
metals). Next, thermoplastic insulator or sheath (e.g. PVC, PE) can be granulated and reused.
Recovery of metals and plastics have economic and ecological reasons [13, 35]. If this type of
waste ends up in a recycling plant, its correct treatment is ensured and there is no danger that
the material ends up as waste on landfills or will be sent and accumulated in underdeveloped
Without recycling, valuable copper core and plastic from cable would end up in landfills,
which are becoming too full to accommodate more waste. The demand for space in landfills is
high, making the cost of dumping waste very expensive. Additionally, buried metals and
plastics could contribute to environmental harm. [14, 72, 73]. Results from study [74] indicate
that several years after the closure of the landfill, elevated concentrations of metals (e.g. iron,
copper, nickel, zinc) are found in the soils and this mean that landfills can be potential sources
of toxic metals to the environment. By [75], metals (e.g. copper, cadmium, lead) were present
in leachate, soil, and in plants that were growing at the landfill. Well-managed landfills are
usually surrounded by protective lining to prevent water leaking to the surrounding
environment. However, local pollution can occur where this is not implemented effectively, or
the lining breaks down and is not replaced [73]. According to extensive international research
project on the long-term behavior of PVC products in landfills and underground (conducted by
the Technical University Hamburg-Harburg, the University of Linköping, and Chalmers
University in Göteborg) PVC products stored in landfills are not posing a risk to human health
and the environment. Toxic metal stabilizers may in fact reach the water of landfills in small
amounts but are more or less insignificant in comparison to toxic metals from other sources in
municipal waste. It is similar to plasticizers which can migrate from soft PVC through
microorganisms. They are broken down and do not lead to a toxically relevant deterioration of
the leakage water [76, 77]. By [78, 79] dumping of PVC in landfills poses significant long-term
environmental threats due to leaching of toxic additives into groundwater (depending on
contains plasticizers, metal-based stabilizers, or type of landfill). There are also risks that PVC
can be burned in a landfill fire where it produces toxic air pollutants (such as dioxin) that can
contribute to unhealthy air and may subsequently enter the food chain [77]. In principle,
valuable materials such as plastics or metals should not end up in landfills [76].
In underdeveloped countries, electric waste, and electronic equipment waste (such as
mobile printed circuit boards, computer, and waste-cables) are recycled by simply burning
them. The copper remains solid and can be collected after burning. Open burning of this type
of waste has a direct environmental impact because it releases toxic emissions to the
surrounding environment (e.g. incomplete combustion of PE, polypropylene and polystyrene
can release carbon monoxide and noxious emissions, while PVC can produce dioxins [73]).
The deposition of the contaminants in soil, sediments, or water accounts for the indirect
impact [35, 80]. In some part of the world (e.g. in Ghana, China, India, Nigeria, and the
Philippines), the informal workers (usually children and adolescents) work for 1012 h per day
and incessantly burn the wires and cables with insulating layer from PVC. This results in the
immediate environment being overwhelmed by thick black smoke, which takes a long time to
clear [80, 81, 82]. Workers usually do not wear protective equipment and lack any awareness
of handling dangerous materials [81]. In addition, it is uneconomical to recover only the metals,
without considering the material of insulating layer or sheath. [35] The correct recycling of
waste-cables allows all of waste (both metals and plastics) to be used perfectly for other
Copper is a 100 % recyclable material (copper does not lose its quality and functionality
during recycling in comparison to that from ore and can be reused multiple times, therefore a
significant part of copper originates from recycling). Recycling copper significantly contributes
to natural resources conservation, waste minimization, energy savings, and cost reduction.
There are so many advantages to recycling copper that the value of scrap is approximately
8595 % the price of newly mined ore [21, 48, 83, 84, 85]. Copper is a trace element that is
essential for plant and animal health therefore it is important for some copper to remain in its
natural state (recycling contributes to conservation this resources). Copper ore is a finite, non-
renewable resource, so once it has all been mined, it will be gone. Currently, only about 12 %
of known copper resources have been mined and consumed [86]. During mining and refining
(purification) of copper, dust and waste gases such as carbon dioxide or sulphur dioxide are
produced, which may have a harmful effect on the environment (e.g. sulfuric acid are produced
when sulphur dioxide combines with water and air; this is the main component of acid rain and
can cause deforestation and the acidification of waterways, which can be deadly for aquatic
life). During copper recycling, there are little, if any, harmful gases emitted (e.g. by using
copper scrap, we reduce CO2 emissions by 65 %) [21, 83, 84, 85, 86]. The recycling of copper
helps to meet the growing demand for copper [84]. According to [83, 84, 85, 86], recycling
copper uses only about 1015 % of the energy necessary for extraction copper from ore. The
conserving energy is very beneficial to the environment because leads to the conservation of
valuable reserves of oil, gas or coal [84, 85, 86]. The copper recycling process is much less
expensive than the process of extracting and refining new copper, and this means that products
from recycled copper are more affordable [86].
PVC has the longest history of recycling of all plastics. Recycling this material has many
environmental and social benefits (e.g. PVC can be recycled by advanced mechanical recycling
systems, large volumes of recyclable PVC waste are available, using recycled PVC helps meet
resource efficiency objectives and allows for the preservation of raw materials, or using
recycled PVC reduces emission and landfill requirements, etc.) [46]. PVC can be recycled
repeatedly up to 8 times depending on the application, without any indication of damage to its
structure (the recycling does not measurably decrease the chain length of PVC molecules)
[46, 87]. One of the special advantages of PVC compared to other materials is the possibility
of changing the formulation to improve the safety and eco-efficiency of the final product, while
maintaining the same level of technical performance [88]. This process can be limited due to
the presence of some additives (e.g. chlorine, cadmium, lead) [89]. Using recycled PVC helps
meet resource-efficiency targets. The energy demand from recycled PVC is typically between
4590 % lower compared to its production from virgin materials [87, 89, 90]. This reduce
reliance on fossil fuels and protect ecosystem from the pollution that can be generated in the
process virgin PVC [87]. According to [91], the recycled PVC reduces global warming potential
by 39 % and water consumption by 72 %. For each ton of PVC recycled, approximately 2 tons
of CO2 are saved (the almost 770,000 tons of PVC recycled in 2019 saved 1.5 million tons of
CO2) [89, 90]. Cost-benefit analysis of recycling the PVC waste showed that recyclation of
PVC waste was preferable and more economically efficient than incineration or landfilling, and
it also creates more jobs than any other end-of-life option [79]. The 740,000 tons of PVC
recycled in 2018 contributed to the creation of more than 1,500 direct jobs in recycling plants
in Europe. By 2030, about 200,000 new jobs will be created, because sorting and recycling
capacity in the European recycling industry is expected to significantly increase [89].
The aim of circular economic at treatment of waste-cables is to recover, recycle and reuse
all waste materials generated in the different phases of them treatment.
Without wires and cables, our society, as we know it, would not exist because a lot of
applications depend on them (such as electricity, electronics, transports, information
technology, home automation). The waste cables are generated in more ways, such as during
the manufacturing process of cables, owing to the end-of-life of cables or end-of-life of electric
and electronic equipment. There is a lot of types of wires/cables of various construction,
containing various parts (such as electric conductor, insulation, auxiliary elements and outer
sheath) and various kinds of materials (e.g. copper, aluminum, PVC, PE, natural rubber, mica
tape). Recovery of metals and plastics from waste cable have economic and ecological reasons
copper and PVC are recyclable material, and their recyclation significantly contributes to the
natural resources conservation, waste minimization, energy savings, and cost reduction. When
this type of waste ends up in a recycling plant, its correct treatment is ensured, and there is no
danger that the material ends up as waste in landfills, or will be sent and accumulated in
underdeveloped countries.
Various technologies can be used to recycle waste cables. The most common waste cable
recycling technology is that of mechanical recycling, which primarily involves cable stripping
and crushing. This technology is simple, low-cost and has strong adaptability. In addition to its
advantages, it also has its limitations, e.g. high energy consumption, high dust and noise
pollution, the technology requires initial manual cutting and leads to severe human resource
waste and extremely low efficiency. The advantage of stripping technology is that there are
lower material losses because we get bigger pieces of metal core and plastic and the
disadvantage is that can be applied to stripping for a particular cable with a certain diameter.
For crushing technology the main advantage can be considered a larger amount of processed
cable waste per day, the disadvantage is e.g. higher energy consumption when crushing cables
during processing. Compared to mechanical treatment technology, cryogenic shredding
technology, ultrasonic separation recycling and high-pressure water jet cutting all have various
advantages, including high recycling efficiency, excellent environmental benefits, and high-
quality products (copper and plastic does not change the physical and chemical properties
during recycling). Their main problem is that the processing scale is small and it’s difficult to
achieve industrialization. Some types of waste cables are difficult to recycle by using the above-
mentioned techniques, and therefore chemical treatment technology has been proposed. If the
aim of chemical technology is obtaining copper, the technology is not suitable because there is
a large amount of metal in waste cables it means that process consumes a large number of
solvents/leaching solutions and thus can easily lead to secondary pollution. A better choice is
to use this technology as a secondary technology treatment if the plastic materials obtained from
the mechanical/physical separation still contain some copper (low-copper-content waste
cables). Another treatment technology is incineration. This technology is simple and one of its
disadvantages is that the surface of the copper core after treatment is severely oxidized thus
decreasing the copper purity. Another problem can be uncontrolled incineration (e.g. illegal
recycling, open burning at landfills, or accidental fires). The cable sheath contains
thermoplastics and flame retardants and the smoke and gas produced from the incineration
process contain toxic gas and dust which can cause severe deterioration to the environment and
harm to human health. Also, other methods can be used for recycling pure PVC and copper
from the waste cables (e.g. PVC swelling and mechanical agitation in hydrophobic organic
solvent mixed with water, PVC swelling and rod milling, a technique involving PVC
embrittlement via plasticizer extraction and crushing by ball milling).
It is not very difficult to recycle clean and homogeneous waste, but there can be problems
with composite products which contain various types of plastics and metals. In such case, it is
necessary to maximize the separation efficiency and subsequently the quality of recovered
products from various types of waste-cables. Therefore, for example, the multi-stage separation
and optimization of the processing conditions must be included in the waste recovery process.
For effective treatment of waste-cables, it is important to choose a suitable technology. The best
choice would be the technology that can treat various types of cables regardless of the type of
cable, material of core or sheath, diameters, etc. The technology of treatment should be
effective, full automated, environmentally friendly, and economically advantageous.
Human health is at risk through our inaction, because we keep producing large amounts of
wastes which are disposed by inappropriate or inefficient techniques. According to [39], only
in Germany alone, about 150,000 tons of waste-cable is generated annually. Every year, it is a
large amounts of waste generated in the world. From this waste we can obtain valuable materials
such as copper or plastic. It is necessary to avoid throwing out the waste which can be recycled.
We cannot prevent or promote longevity with how we treat our Earth. It is necessary to produce
it in a sustainable way, while limiting consumption and waste this is the aim of circular
economy. In the circular economy, production and consumption are regulated in such a way
that products can be reused, repaired and recycled. According to [66], throwing and wasting are
no longer trivial acts today, and it is deplorable that they have been.
The research was supported by the Slovak Research and Development Agency under the
contract No. APVV-16-0223.
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Lenka Blinová 0000-0001-6971-6558
Peter Godovčin 0000-0003-4531-417X
... Wire insulation obtained from waste electronic equipment, household appliances and cars is the source of plasticised PVC recyclate. The mechanical separation of the insulation from the metal core is not a problem [62][63][64][65][66][67][68][69]. A polymer mixture is obtained with PVC as the main polymer [66,70]. ...
... The mechanical separation of the insulation from the metal core is not a problem [62][63][64][65][66][67][68][69]. A polymer mixture is obtained with PVC as the main polymer [66,70]. It is easy to separate with the already mentioned methods. ...
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Bearing in mind the aspiration of the world economy to create as complete a closed loop of raw materials and energy as possible, it is important to know the individual links in such a system and to systematise the knowledge. Polymer materials, especially poly(vinyl chloride) (PVC), are considered harmful to the environment by a large part of society. The work presents a literature review on mechanical and feedstock recycling. The advantages and disadvantages of various recycling methods and their development perspectives are presented. The general characteristics of PVC are also described. In conclusion, it is stated that there are currently high recycling possibilities for PVC material and that intensive work is underway on the development of feedstock recycling. Based on the literature review, it was found that PVC certainly meets the requirements for materials involved in the circular economy.
... The schematic of the mechanical process of separating the cable sheath from the plastic material. Based on[39].The efficiency of wire strippers can vary depending on the following[40]: ...
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Civilization and technical progress are not possible without energy. Dynamic economic growth translates into a systematic increase in demand for electricity. Ensuring the continuity and reliability of electricity supplies is one of the most important aspects of energy security in highly developed countries. Growing energy consumption results not only in the need to build new power plants but also in the need to expand and increase transmission capacity. Therefore, large quantities of electric cables are produced all over the world, and after some time, they largely become waste. Recycling of electric cables focuses on the recovery of metals, mainly copper and aluminum, while polymer insulation is often considered waste and ends up in landfills. Currently, more and more stringent regulations are being introduced, mainly environmental ones, which require maximizing the reduction in waste. This article provides a literature review on cable recycling, presenting the advantages and disadvantages of various recycling methods, including mechanical and material recycling. It has been found that currently, there are very large possibilities for recycling cables, and intensive scientific work is being carried out on their development, which is consistent with global climate policy.
... The cable consists of an electrical conductor (copper or aluminum metal core), an insulator (plastic), auxiliary elements (cable shielding material), and an outer sheath (covering all materials). Insulating material consists of thermoplastic (mainly PVC, polyolefins, polyethylene, and polyurethane) and thermoset (ethylene propylene, cross-linked polyethylene, ethyl vinyl acetate, silicone, neoprene, and natural rubber) [22]. Ceramic terminal blocks are used for power and thermocouple wiring in high-temperature locations. ...
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The increasing world population and the development of technology have boosted the demand for electrical and electronic equipment (EEE). Equipment that has completed its life cycle causes serious damage to the environment due to its toxic components. In addition, it contains many more base metals (copper, aluminum, nickel, lead, tin, etc.) and precious metals (silver, gold, palladium, platinum, etc.) compared with a run of mine ore. Recycling these values with an economic and environmental understanding will ensure sustainability and prevent the rapid depletion of natural resources. Specific gravity, magnetic, electrostatic, optical, surface, thermal, and other property differences between particles as well as the shape, size, and distribution of individual particles directly determine the success of the recycling process. By determining the behavior of the particles during enrichment and producing grains suitable for enrichment with better performance in the size reduction stage, the quality of the concentrate to be subjected to the final chemical/metallurgical treatment will be enhanced. The main aim of this study is to reveal the effect of particle size and shape properties on the recovery of valuable metals from two different waste electrical and electronic equipment (WEEE) sources, end-of-life printed circuit boards and waste electric wires, using environmentally friendly, easier-to-use, and cost-effective mechanical, physical, and physiochemical processes. Deciding on the most suitable enrichment process after detailed characterization of the products obtained from different comminution equipment and their particle size and shape directly affected the amount, content, and recovery of the final concentrate.
... Hazardous chemical additives (such phthalates) may leak out of PVC components of electronic items when they are dumped in a landfill. Dioxin is released when PVC is burned (Blinová & Godovčin 2021). The majority of polymers (26%) used in 16 electronics are PVC, which is utilized for computer casing and cabling. ...
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In this chapter, the authors discuss the utilization of e-waste in the concrete for civil construction activities. Various tests have been used to investigate the effects of e-waste mixed with concrete. The various percentages of e-waste have been mixed with concrete to improve the strength of buildings. An e-waste concrete beam has a maximum tensile strength of 6.23 MPa under sulfuric curing conditions, and the highest flexural strength at 10% e-waste replacement during the hydrochloride curing process. The compressive strength is at its highest value when e-waste replaces 10% of it. After 28 days of curing, the concrete cylinder's maximum split tensile strength was 15%. Thus, the e-waste could be effectively utilized for civil construction purposes to reduce its environmental impacts.
... 216 cubes, 313 cylinders, and 48 beams, respectively, were cast, cured, and tested for compression, split tensile, and deflection. This study looked at how the amount of coarse aggregate replaced with e-waste affected the strength of concrete (Blinová & Godovčin, 2021;Cherukuri et al., 2018;Julander et al., 2014). ...
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In this chapter, the authors discuss the utilization of e-waste in the concrete for civil construction activities. Various tests have been used to investigate the effects of e-waste mixed with concrete. The various percentages of e-waste have been mixed with concrete to improve the strength of buildings. An e-waste concrete beam has a maximum tensile strength of 6.23 MPa under sulfuric curing conditions, and the highest flexural strength at 10% e-waste replacement during the hydrochloride curing process. The compressive strength is at its highest value when e-waste replaces 10% of it. After 28 days of curing, the concrete cylinder's maximum split tensile strength was 15%. Thus, the e-waste could be effectively utilized for civil construction purposes to reduce its environmental impacts.
Polyvinyl chloride (PVC) recycling is crucial for mitigating the environmental impact of PVC wastes, which take decades to decompose in landfills. This review examines the current state of PVC recycling processes, focusing on challenges and future research opportunities. It explores the types and sources of PVC wastes, including post-consumer, industrial, and construction wastes. Conventional recycling methods such as mechanical, thermal, and chemical recycling are discussed, highlighting their advantages, limitations, and successful applications. Furthermore, recent advances in PVC recycling, including biological, plasma-assisted, and solvent-based recycling, are explored, considering their potential benefits and challenges. The review emphasizes the European context of PVC recycling, as the region has implemented regulatory initiatives and collaborations. It points out the Circular Economy Action Plan and directives targeting PVC waste management, which have promoted recycling and established a supportive framework. Challenges of current PVC recycling methods and technologies, such as low yield and high energy consumption, are identified. The review calls for the development of efficient and cost-effective recycling technologies, along with improvements in recycling infrastructure and consumer awareness. Assessing the environmental and economic impacts, PVC recycling significantly reduces greenhouse gas emissions and conserves resources compared to virgin PVC production. The economic benefits include job creation and reduced raw material costs.
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Mobile phones are among the most widely used devices worldwide, but they also present a serious environmental contamination issue. Mobile phones often contain dangerous materials that, if not properly handled and disposed of, will leak into the environment. To ascertain the level of contamination, risk assessment techniques must be developed. In this research, national and international scenarios and regulating measures have been discussed for the harmfulness and management of mobile waste materials. The various characteristics of mobile wastes and materials flow for the processing of mobile related wastes have been elaborated. The different types of frameworks for the indicating systems, selection criteria, and risk assessment indication systems were also illustrated. The various stages of mobile waste handling and processing to recover polymers have also been represented.
The rapid technological advancement of the manufacturing sector over the past few decades inevitably led to the rise of Industry 4.0. It has the potential to significantly alter how globalisation is practiced in the production and consumption of products and services across international markets. In this chapter, we'll take a closer look at the rise of Industry 4.0 and the new technical architecture that underpins it, as well as the benefits it's expected to bring.In addition, how we may use technology to fortify a company's competitiveness and shield it from the perils of this transformation. The new global division of labour, the worldwide supply chain, and the global value chain will all be profoundly affected by this multifaceted technology, as evidenced by a thorough examination of the relevant literature. It will alter the competitive landscape by shifting the advantage away from large corporations and toward small and medium-sized enterprises (SMEs) in emerging markets and developed markets. As human and technological skills advance quickly, businesses may be able to profit.
Waste management represents a challenge due to the rapid increase in waste production and the emerging of new waste types. Overcoming the issue involves using innovative technologies such as nanotechnology. Nanotechnology uses nanomaterials, which are materials that have at least one dimension less than 100 nm. Due to their small size, these materials increase reactivity in processes such as adsorption and oxidation/reduction. The application of nanotechnologies is significant in the production of new materials to replace current raw materials, and in providing novel solutions for waste recycling and disposal. Furthermore, nanofiltration is effective in the treatment of metals, toxic waste, and nonbiodegradable materials of leachate. Nanomaterials, however, represent a safety risk for the environment, and a serious threat to human health due to their small size and long suspension time. This chapter deals with the use of nanotechnology in waste management, including reduction, recycling, treatment, and disposal phases.
Small electronic waste has been addressed in this chapter. With this, issues such as consumption and generation, composition and recycling techniques were raised. The equipment/waste addressed were cell phones and smartphones, LED lamps, computers, and electrical wires and cables, which were chosen due to their great generation, for being more current technologies, their great applicability and quantity, and variety of valuable and critical materials in their compositions. All this waste shows a notable quantity and variety of precious and technological metals, and of rare-earth elements, all metals of great interest and research today. All except electrical wires and cables show considerable portions of gold, for example, which is a precious metal of great applicability, and which has been achieving high yield values, being, with this, one of the metals most studied by researchers. On the other hand, electrical wires and cables are waste, which is present in almost every WEEE, and are rich in copper and PVC, which are materials of great use in the most diverse areas. In any case, there is a need for the development of viable techniques of recovery of these metals, as well as the development of viable industrial processes. Important steps, such as disassembly and mechanical processing, should be developed, as they enable better revenues, in addition to the development of more sustainable and productive recovery procedures. As well as the development of designs that aim to facilitate the end of life of these products, seeking to meet the precepts of the tripod of sustainability, industrial ecology, and, more recently, the circular economy strategy, where all materials, not only metals, of this waste are recovered, valued, and recycled.
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Landfills are major sources of environmental pollution. This study evaluated heavy metal concentrations in soils and plants around the closed Lumberstewart landfill in Bulawayo, Zimbabwe, to determine the pollution potential of a closed landfill and the risks they present to plants growing in this environment and surrounding communities. Soil samples were collected at depths of 0–30 cm, 30–60 cm, and 60–90 cm around the landfill and at a control site and characterized for various properties and concentrations of Cd, Cu, Cr, Fe, Ni, and Zn. Samples of Datura stramonium, collected from the same sites where soil samples were collected, were also analyzed for the same heavy metals. The soils were sandy, mostly acidic (5.01 < pH < 7.65) with low organic matter content (<2%) and cation exchange capacity (<15 meq/100 g). These properties varied with depth around the landfill. Heavy metals concentrations in the soils and Datura stramonium followed the order Fe > Zn > Cu > Cr > Ni > Cd with samples from around the landfill having higher concentrations than samples from the control site. Soil heavy metal enrichment was highest at a depth of 30–60 cm. Pollution load index (PLI) values indicated that all sites around the landfill were polluted (PLI > 1). Heavy metal transfer coefficient in Datura stramonium ranged between 0.0 and 209 with <60% of the variation observed in heavy metal transfer coefficient in Datura stramonium explained by the extent of heavy metal enrichment in the soils. More than 20 years after closure of the landfill, there are indications that leachate migration may still be going on around the landfill. Monitoring of environments around closed landfills needs to be ongoing to mitigate negative impacts on humans and the environment.
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Municipal waste incinerator bottom ashes contain copper contents comparable to those of low-grade ores in addition to other valuable metals. While the processing of coarse fractions (>2 mm) is state of the art, the fines with their residual metal content are landfilled. This paper presents the results from a mineralogical characterization of fine fractions from the processing of municipal solid waste incinerator bottom ashes. From the results, possible approaches for a recovery of copper from the fine fraction are derived. Spatially resolved phase analysis reveals that the material contains a very heterogenic mixture of naturally occurring compounds as well as particles of alloys, metals, artificial oxides, and sulfides. The most interesting element to recover is copper. Copper can be found in the form of alloys, simple sulfides (XS), and oxides (XO). During the incineration process, new phases are generated that differ from natural ones and therefore can be called artificial minerals. Additionally, several components are partially altered due to oxidation, especially after the prolonged outside storage of the bottom ash. Crystalline silicate and glass particles are only sporadically enriched in Cu. Based on these results, different processing techniques are discussed. Due to the small particle size distribution and the physical and physico-chemical properties of the particles, flotation seems to be the most promising technique for the enrichment of copper from municipal solid waste incineration bottom ash (MSWI-BA) fine fractions.
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The Global E-waste Monitor 2020 provides the most comprehensive overview of the global e-waste challenge, explains how it fits into international efforts to reach the Sustainable Development Goals, and discusses how to create a sustainable society and circular economy. The report provides a national and regional analysis on e-waste quantities and legislative instruments, and makes predictions until 2030. It also encourages decision-makers to increase activities to measure and monitor e-waste using an internationally recognised methodological framework. Visit for more information.
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This study examines the link between selected indicators of a circular economy, including essential components of environmental and economic growth. Developed economies are continuously innovating to promote growth and giving governmental support to the producers to move from linear economies to circular ones. Hence, waste materials in industrial systems are recycled or re-used, improving the efficiency of using finite resources with the no-waste approach. The aim of this paper is the following: (1) to identify the main components of a circular economy, which are also supportive of sustainability and development; (2) to check the impact of these variables in the economic growth of European Union countries; (3) to find out if the three components of sustainable development adopted to circular economy (CE) indicators (environmental-social-economic) are significant to economic growth. We used a fixed effect panel data analysis to identify the circular economy's impact on the economic growth of European countries. Additionally, to support the results of the regression analysis, we employed a second method-generalized methods of moments-computing the Arellano-Bond dynamic panel data estimation method. The model included five independent variables, such as environmental tax rate, a recycling rate of waste, private investment and jobs in a circular economy, patents related to recycling, and trade of recyclable raw materials. The identification of each variable was made based on a deep search through literature. The results of both econometric models showed a strong and positive correlation between a circular economy to economic growth, highlighting the crucial role of sustainability, innovation, and investment in no-waste initiatives to promote wealth.
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Mining activities have resulted in the existence of dumps, which generally present a perpetual danger of moving and transforming toxic elements. The experimental study was carried out in Nizna Slana (Slovakia) where the main source of emission was the iron-ore mining–processing factory focused on siderite mining. Siderit from Nizna Slana is highly ferrous with an increased level of the Mn content. Among the undesirable impurities on the deposit are mainly As, S, Pb, and Zn. According to the environmental regionalization of the Slovak Republic, the surveyed area represents a region with a slightly disturbed environment. The BIOLOG® Eco plates method was used for ecotoxicological evaluation of contaminated soils, where soil enzymes (acidic and alkaline phosphatase and urease) were also monitored in soils and soil contamination was evaluated according to Hakanson (1980). Based on the results obtained, it can be concluded that the content of Hg, Cd, Cr, Cu, As, Fe, Mn, and Mg is above the toxicity level. As, Fe, Mn, and Mg are the most serious pollutants in the area under investigation, and their pronounced excess indicates contamination, where harmfulness and toxicity can be expected. Based on the evaluation of the contamination factor and the degree of contamination, the soils in the emission field of old mining works are very highly to slightly contaminated with heavy metals. The experimental results in the real environment showed that the activity of soil enzymes showed considerable differences, and, regarding the functional diversity of soil microorganisms, we have not seen significant spatial variability.
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Ventilation-controlled fires tend to be the worst for toxicity, because they produce large amounts of fire effluent containing high yields of toxic products. In order to examine the dependence of the amount of chosen few main combustion gases under ventilation-controlled conditions, a PVC-insulated copper electric wire with unknown composition (PVC filled with chalk) was studied by mean of a steady state tube furnace. For the tested wire, lower values of CO2 yields at different ventilation conditions were obtained than for the reference pure polymer unplasticized PVC and additionally tested pure LDPE, the yields were higher three times in the case of PVC and two times in the case of LDPE than those received for wire at the same ventilation conditions, which pointed out decreasing contribution of hyperventilation effect to human during cable fire. In contrast, higher values of toxic CO yields, four times higher, were obtained for the PVC-insulated electric wire rather than for the pure polymers. The maximum value of CO yield (0.57 g/g) was determined in the case of 5 L/min of primary airflow and decreased with increasing ventilation. The measured yields of hydrocarbons were similar to the reference values except for the equivalence ratio f = 0.27, where hydrocarbon yield was equal to 0.45 g/g. The HCl yield of fire effluents from the PVC-insulated wire was shown to be independent of ventilation conditions. The corrosive reaction between copper and the HCl species and the flame-retardant mechanisms of the additives, caused the lower values of HCl in the fire effluent of the PVC-insulated copper wire than for pure polymer.
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Waste from information technology (IT) and telecommunication equipment (WITTE) constitutes a significant fraction of waste from electrical and electronic equipment (WEEE). The presence of rare metals and hazardous materials (e.g., heavy metals or flame retardants) makes the necessary recycling procedures difficult and expensive. Important efforts are being made for Waste Printed Circuit Board (WPCB) recycling because, even if they only amount to 5–10% of the WITTE weight, they constitute up to 80% of the recovered value. This paper summarizes the recycling techniques applicable to WPCBs. In the first part, dismantling and mechanical recycling techniques are presented. Within the frame of electro-mechanical separation technology, the chain process of shredding, washing, and sieving, followed by one or a combination of magnetic, eddy current, corona electrostatic, triboelectrostatic, or gravity separation techniques, is presented. The chemical and electrochemical processes are of utmost importance for the fine separation of metals coming from complex equipment such as WPCBs. Thermal recycling techniques such as pyrolysis and thermal treatment are presented as complementary solutions for achieving both an extra separation stage and thermal energy. As the recycling processes of WPCBs require adequate, efficient, and ecological recycling techniques, the aim of this survey is to identify and highlight the most important ones. Due to the high economic value of the resulting raw materials relative to the WPCBs’ weight and composition, their recycling represents both a necessary environmental protection action, as well as an economic opportunity.
Novel methods for recycling waste wire harnesses, namely, dry rod milling (which involves the swelling of the cables followed by milling) and wet rod milling (which involves the simultaneous swelling and milling of the cables), were developed for the simultaneous recovery of the Cu wires, polyvinyl chloride (PVC) coatings, and phthalate plasticizer in high purity. The swelling of the PVC coatings facilitated the separation of the coatings from the Cu wires at moderate rod milling speeds and allowed for the extraction of the plasticizer. n-Butyl acetate was used as the swelling solvent and resulted in a sufficient degree of swelling (the volume increased to ~3.5 times that of the original cables), thus allowing for the quantitative extraction of the plasticizer, which was diisononyl phthalate (DINP). The complete striping of the PVC coatings and Cu wires from 20-cm-long cables could be performed within 60 min by both dry and wet milling at a low rotation speed (15 rpm). Furthermore, more than 90 wt% of the Cu wires longer than 10 cm could be recovered for subsequent Cu refining. The used n-butyl acetate was regenerated by distillation and exhibited PVC swelling properties comparable with those in the fresh state. Thus, the developed methods allow for the successful quantitative recovery of high-purity Cu, PVC, and DINP without requiring any of the complex multistep physical separation processes involved in the conventional granulation technique for the recycling of waste wire harnesses.
Circular economy focuses on the extension of material and resource circularity within the economic system in order to minimize the extraction of natural resources. Attaining such circularity requires the integration of adverse impacts on the place in which the process takes place, as not all recycling activities occur within the same perimeter. The shipbreaking phenomenon epitomizes the circularity of metal that helps reaching the circular economy targets, but is often carried out far from the origin of the commodity, raising issues regarding proximate recycling. This study illustrates this aspect by analyzing the global ship flow pattern, domestic metabolism, and global environmental savings. Our results suggest that size of the ships rather than flagging pattern determines the recycling destination, as smaller ships are recycled in standard destinations despite being popularly flagged while large ships are recycled in substandard destinations despite being owned by standard recycling nations such as Turkey. We also see that shipbreaking avoids (70-90%) environmental impacts at the cost of (1-5%) disposal impacts and (5-20%) domestic processing impacts. Evaluating proximate recycling against distant recycling shows that former perform worse by far (95 against 184) than distant recycling. We suggest that pursuing distant recycling rather than proximate recycling is globally imperative and thus, a beyond-border extended producer responsibility can be initiated to minimize beyond border adverse impacts of distant recycling.