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Copyright© PMAS-Arid Agriculture University Rawalpindi, Pakistan http://jaab.uaar.edu.pk
Journal of Applied Agriculture and Biotechnology 2016 1(1): 13−26
ISSN: xxxx-xxxx
Review article
Solid waste management in Saudi Arabia: A review
Muzammil Anjum1*, Rashid Miandad1, Muhammad Waqas1, Ijaz Ahmad1, Ziad Omar Ahmad Alafif1,
Asad Siraj Aburiazaiza1, Mohamed Abou El-Fetouh Barakat1, Tasneem Akhtar2
HIGHLIGHTS
Municipal solid waste is generated in huge amount in Saudi Arabia
The current practices of MSW management are causing negative environmental impacts
A shift from waste to energy approach can decrease the burden on fossil fuel
Anaerobic digestion of food waste generates methane while pyrolysis of plastics produces liquid fuel oil
Authors affiliation
1Department of Environmental
Sciences, Faculty of Meteorology,
Environment and Arid Land
Agriculture, King Abdulaziz
University, Jeddah-21589, Saudi
Arabia
2Department of Arid Land
Agriculture, Faculty of Meteorology,
Environment and Arid Land
Agriculture, King Abdulaziz
University, Jeddah-21589, Saudi
Arabia
*Corresponding author
Muzammil Anjum
Email: muzammilanjum@gmail.com
How to cite
Anjum, M., R. Miandad, M. Waqas, I.
Ahmad, Z.O.A. Alafif, A.S.
Aburiazaiza, M.A. Barakat and T.
Akhtar. 2016. Solid waste
management in Saudi Arabia: A
review. J. Arid Agri. Biotechnol., 1(1):
xx-xx
ABSTRACT
he problem of municipal solid waste (MSW) management is
critical to the Kingdom of Saudi Arabia (KSA). MSW contains two
major components, organic waste and plastics. The organic
waste is generated due to the extensive use of food, while the
massive use of disposable stuff is the main source of plastic waste,
especially during the visit of a large number of pilgrims every year. In
the current scenario, the management of waste by conventional
methods such as dumping causes significant environmental impacts,
including greenhouse gas (GHG) emissions, leachate production and soil
contamination. The problems associated with the uncontrolled dumping
can be avoided by shifting to waste-energy approaches, leading to
economic and environmental sustainability. This review focuses on the
current status of the waste disposal system in KSA and its environmental
impacts. Based on the overall current situation and types of solid waste
production in KSA, waste treatment methods such as anaerobic
digestion and pyrolysis processes have been proposed. The anaerobic
digestion could be used for treating the organic fraction of municipal
solid waste, wherein the methane produced during the process can be
used as fuel after up-gradation or converted to liquid fuels. On the
other hand, pyrolysis is highly suitable for the treatment of plastic waste
because of non-biodegradable nature and pyrolysis of plastics can result
in the production of a variety of value- added products, such as fuel oil,
char and gases. Keeping in view the positive aspects of anaerobic
digestion and pyrolysis, there is a great potential to use these
technologies in KSA to make waste management practices highly
effective and eco-friendly.
Key words: Solid waste, Saudi Arabia, Anaerobic digestion, Pyrolysis, Landfill
T
Anjum et al. 2016 J. Appl. Agri. Biotechnol. 2016 1(1): 13−26
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1. Introduction The Kingdom of Saudi Arabia (KSA)
is located in the South Western Asia, encompassing
Red Sea at west to the Arabian Gulf at east and lies at
16o 22’, 32o 14 N and 34o 29’, 55o 40’ E longitudes.
The country dwells a population of 30.8 million
according to World Bank data (WB, 2015). The KSA
witnesses a rapid population growth, industrialization
and urbanization in the last few decades, resulting in
the production of a huge amount of solid waste
(Gajalakshmi and Abbasi, 2008). The average increase
in population growth over the last four decades was
recorded 3.4%, while the urbanization increases from
50 to 80% of the total population in 1970 to present.
This scenario has raised the problem of enormous
amount of unchecked solid waste generation (Ouda et
al., 2013), where most of the waste is produced in
some of eight main cities of KSA (Table 1). The rate of
municipal solid waste (MSW) generation in KSA is 15.3
Mt/y with the average rate of 1.4 kg/capita/d (Nizami
et al., 2015a). The produced MSW is generally
regulated by the Local Affair and Ministry of
Municipalities, while the management is carried out
by the local municipalities, which include the
collection, transportation and disposal of waste to
landfill or dump sites without material or energy
recovery (Ouda et al., 2013). The waste is usually
disposed through landfill dumping and combustion.
Some compost facilities have also established for
conversion of organic waste into compost. However,
the prevailing waste disposal practices are posing
serious threats to the environment. The disposal of
wastes without proper treatment can trigger problems
like malodors and pollution of ground and surface
waters (Al-Sabahi et al., 2009). Furthermore, these
waste management practices are liable for second
highest share of GHG emissions (CO2, CH4, N2O) after
fossil fuels (Rahman and Khondaker, 2012). The
majority of the dumping sites in KSA are expected to
reach their capacities in coming few years (Ouda et al.,
2013). Thus, there is a need to shift from prevailing
waste management practices to some advance
technologies such as waste to energy approaches.
The waste produced in KSA contains large amount of
organic wastes (about 40%). Organic waste is
comprised of food waste from different sources like
hotels, restaurants, canteen, homes etc. (Adhikari et
al., 2008). In order to transform these organic wastes
to valuable product, composting is one of the
economical and environment friendly methods (Zhang
et al., 2010).
Table 1: Solid waste production in different cities of
KSA (Ouda et al., 2013; Tolba and Saab, 2008; CDSI,
2004).
The process of composting is based on aerobic bio-
conversion of waste into fertilizer due to the activity of
microorganisms (Alruqaie and Alharbi, 2012). In the
case of food waste which are too wet, can also be
treated through anaerobic digestion. During anaerobic
digestion, methane is produced due to the
decomposition of organic content in the absence of
oxygen and energy is released as a biogas (Svensson et
al., 2004). In other technologies such as incineration,
the energy is produced through combustion of solid
waste (Kameswari et al., 2007). In many countries,
incineration remained the most important part of
MSW management. During this process, waste is
mixed thoroughly to maintain a more constant heating
value and then delivered to furnace for combustion
process (Psomopoulos et al., 2009). The wastes are
then burnt in excess of oxygen at about 800 oC
temperature.
In MSW, plastic is the second most abundant waste
produced in KSA. During the holy month of Ramadan
and Hajj, large amount of plastic waste is produced
due to use of disposable plastic containers and bags
for drinks and food stuff (Abdul Aziz et al., 2007). Only
1520% of all produced plastic waste is recycled by
sorting method whereas the disposal of plastics
wastes to landfill results in the environmental and
Region /City
Population
(millions)
Amount of waste
(x 103 tons per year)
Saudi Arabia
30.8
15,300
Major cities
of KSA
14.12
8633
Riyadh
5.328
2871
Jeddah
3.456
1888
Makkah
1.675
915
Madina
1.180
645
Al-Taif
0.987
540
Dammam
0.903
1093
Al-Hassa
0.60
681
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operational overburden to the landfill due to slow
degradation process. In this context, the pyrolysis
process can be used for treating plastic wastes
material with generation of energy in the form of fuel
oil and valuable products like char (Sharma et al.,
2014). During this process, plastic material is
decomposed thermo-chemically in the absence of air
(oxygen) at temperature up to 500 oC. The products
produced are liquid (fuel oil), solid (charcoal) and a
small gaseous fraction. The oil has similar
characteristics as diesel having high cetane and lower
sulphur content (Sharma et al., 2014). Although,
numbers of technologies are available having their
own environmental and economic implications, the
selection of waste treatment method is most
important step. Figure 1 describes an overview of the
waste management hierarchy for various technologies
with respect to their environmental and economic
outcomes.
In the present review, the existing practices in KSA for
waste management and their concerning
environmental effects are discussed. Furthermore, the
feasibility of modern waste treatment methods has
been suggested for the effective management of solid
waste with respect to its production in KSA.
2. Current practices of waste management
in KSA
2.1. Waste collection and dumping
The current management system of MSW in KSA is a
simple practice i.e. collection and dumping in landfill
sites (Ouda et al., 2013). Most of the solid waste in big
cities is disposed through the same way e.g., the waste
dumped at Makkah landfill is about 1800-2000
tons/day in normal days, while during Ramadan the
amount of waste increased to 3000 tons In Jeddah,
solid waste is collected through large bins placed all
around the commercial and residential areas. The
collected waste is first taken to the transfer stations
and then ultimately sent to the dumping site. The
landfill facility located at Buraiman, Jeddah receives
about 1.5 million tons of solid waste every year (Zafar,
2015) and 4500 tons/day during Hajj (AbdulAziz et al.,
2007).
Waste
Dumping
Economy
Incineration
Composting
Anaerobic
Digestion
Pyrolysis
Environment
High operational cost
with no economic
outcome
Ground water
pollution, odor
Produce Thermal Energy
Organic fertilizers
Degrade biodegradable
organic waste only
Air Emissions: Fly ash
Bottom ash
Bioenergy
(Methane)
Crude oil: liquid
fuel, Char
Degrade plastic waste,
Few air emissions
Degrade organic waste
Decrease GHG emissions
Solid
Waste
Figure 1: Solid waste management hierarchy for
various technologies.
Composition of MSW received at waste dumping sites
depends on the source and community and varies
greatly from city to city. On average, MSW consists of
organics as a major fraction (40%), out of which food
waste is the prominent waste stream (50.6%) (Abdul
Aziz et al., 2007). Food waste contains rice (38.7%),
meat (25%), bakery products (18.7%), and fats (13%)
as major fraction (Adhikari et al., 2008). Plastic is the
second largest stream found in the MSW which is
about 5-17%. However, some other components are
also found in waste stream, which include textile
(6.4%), glass (4.6%) and minerals (8.1%) (Khan and
Kaneesamkandi, 2013). Table 2 shows the overall
composition of municipal solid waste generated in
KSA.
At present, most of the dumping sites in KSA are
matured landfills, which imply that a substantial
amount of waste has been dumped and will reach to
the capacity of the landfills in coming few years. The
dumping of other waste types, such as wastewater
sludge are also posing problems of leachate, methane
generation, odor and other health hazards (Ouda et
al., 2013). In general, the dumping of waste without
engineered landfill system is an old practice as
followed in KSA. It causes number of environment risk.
For example, lack of gas collection systems cause
methane emissions directly into the air, when landfill
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sites reach to its capacity (closed landfill) it cannot be
used for other purposes like construction of building,
etc. because dumping land takes many years for
settlement due to continuing degradation of organic
waste under the ground.
2.2. Makkah waste dumping site: A case study
A survey was conducted to Makkah waste dumping
site in April, 2015 to observe the present conditions
and practices at dumping site. The interview from site
manager, labors and officer worker was conducted. An
overview of results obtained during our survey is
presented in Table 3, showing some facts regarding
Makkah waste dumping site. The Makkah landfill is
located 21o15’44.48” N and 39o48’26.04”E. The waste
is collected by Makkah municipality and landfill
operation is operated by the Dala Company. The
area features desert climate conditions. The land area
is porous and has high chances of percolation of
landfill leachate. The site is only used as dumping of
waste, so may be termed as non-engineered landfill.
Total area covered by the waste dumping site is 4 km2.
Table 2: Composition of municipal solid waste produced in KSA (Tolba and Saab, 2008; Ouda et al., 2013; Khan and
Kaneesamkandi, 2013)
S #
Waste Categories
Fraction (%)
Components
1
Organic materials
65.5
Food waste and paper materials
Food Waste
37.0
Food stuff, fruits and vegetable refuse, peel etc.
Paper
28.5
Wasted Papers, cardboard, box board, bags, magazines, tissue
papers, newspapers, toilet papers,
2
Plastics
5.2
Disposable glass, spoons, plates, wrapping films, wrapping film,
bags, plastic bottles and polythene
3
Glass
4.6
Bottles, glassware, bulbs, ceramics etc.
4
Wood
8.0
All products comprised of wood
5
Textile
6.4
Cloths, dippers etc.
6
Metals/minerals
8.3
Cans, knives, wires bottles , aluminum cans, foils
7
Others
2.0
Leathers, rubber, fibers, rubber, yard waste, soils, tyres,
appliances and electronics and appliances
Table 3: Description of Makkah landfill site and operational facilities
Features
Description
Location
21o15’44.48” N and 39o48’26.04”E
Climate
Desert climate condition
Total area
4 km2
Waste received
4000 - 6000 t/d
Waste received during Hajj and Ramadan
10,000 t/d
Waste Origin
Makkah city
Waste Source
Domestic and commercial entities
Waste Categories
Non-hazardous
Operational Time
24 h
Total machinery (Compactor, Bulldozers etc.)
11
Field Labors
60
Office workers
5
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The area is under operation for last 10 years and has
capacity to receive waste further for only three more
years. The landfill receives 4-6 thousand tons of waste
on daily basis and the amount is increased up to 10
thousand tons during peak seasons of Hajj and
Ramadan month. The site received the waste
throughout the week and 24 hours of a day. The
waste is produced by domestic and commercial
entities of the Makkah city and consisted of food
wastes, plastic, paper and aluminum cans. The area
also receives the old tyres of the vehicles which are
placed above the ground. About 4 million tyres are
currently thrown at the dumping site. For the dumping
of waste, landfill utilizes the different types of
machinery and vehicles. The solid waste is received by
trucks and processed by different machineries i.e.
bulldozers, shovels, graders, and compactors. The
compactors are used to compress the waste to reduce
its volume, whereas, bulldozers are used for leveling
of the land after waste dumping. Total working staff is
sixty five, with sixty people as labor and five as office
bearer. The labors perform various duties like digging,
waste compressing and dumping through machines.
Figure 2 shows some images of the Makkah waste
dumping site captured during the visit. We found that
current landfill is an example of uncontrolled dumping
of waste (non-engineered landfill). This uncontrolled
dumping can pollute groundwater and soil, and
responsible of attracting disease-carrying insects and
rats. The continuous flow of leachate was observed at
downstream area from old dumping sites. The
leachate from landfill usually is composed of four
types of compounds: inorganic macro components,
dissolved organic matter, xenobiotic and heavy metals
(Kjeldsen et al., 2002). The improper collection and
management of leachate may cause soil and water
pollution (USEPA, 2002). As climate of the area is hot,
it increases evaporation of leachate and hence may
add volatile organic compounds in the air, causing air
pollution. Besides the leachate problem, another
Leachate accumulation
(downstream area) Waste dumped mountain
(upstream area)
Figure 2: Pictography of Makkah waste dumping site.
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major issue is bad odor which is produced due to
biological degradation of the solid waste heaps.The
compaction of landfill layers and biodegradability of
organic waste creates anaerobic conditions which is
responsible for production of methane gas (Kjeldsen et
al., 2002). As, there is no gas collection system exist,
the gases are directly released into the atmosphere
from old dumping cells, increasing GHG potential. The
gas released from the landfill may catch the fire and
could be responsible for major accident (USEPA,
2002).
2.3. Composting of organic waste
In KSA, there are many facilities constructed for the
conversion of waste like food waste, manures and
plant residues to compost for agricultural purpose (Al-
Turki et al., 2013). The composting is a process of
aerobic degradation of organic waste which can be
helpful to reduce negative environmental impacts of
organic waste and produce organic fertilizers (Simandi
et al., 2005). KSA has desert climate and only 835,000
ha of land is associated with agriculture (GIZ, 2012),
thus composting of waste for agriculture application
would not be very effective. However, various
initiatives have been taken to promote the organic
agriculture and use composted products from organic
waste. The introduction of the 1st National Regulation
and Standards for Organic Agriculture in 2011 is one
on the clean examples of raising focus on developing
strong organic farming system (GIZ, 2012).
Composting is an efficient technology for recirculation
of waste to valuable products and can reduce
problems originating from waste disposal sites
(Svensson et al., 2004). The soil application of
compost can positively influence the water holding
capacity, organic matter status, cation exchange
capacity of soil and provide maximum availability of
the nutrients to plants (Alzaydi et al., 2013).
Conversely, the low quality compost has a negative
impact on soil properties and plant growth. The
chemical properties that indicates the compost quality
are pH, organic matter, carbon to nitrogen ratio,
electrical conductivity (EC), nitrate and ammonium
levels and heavy metal contents (Bernal et al., 2008).
In order to assess the quality of compost, several
private and official authorities established standards
and regulations to check the compost quality for
agricultural application and environmental protection.
Recently, some of the Arabic Gulf Countries also
document regulations for the quality of imported and
local made compost (GCST, 2006).
Composting is an economical and ecofriendly
approach for waste management, but the quality of
the compost produced in KSA is not coinciding with
the international standards. Research study has been
done by Al-Turki et al. (2013) in which they
investigated the chemical characteristics of twenty
five composts produced in Saudi Arabia. Their aim was
to investigate and compare the quality of compost to
international and local standards of compost quality.
They found that there exists a large variation between
the standards and chemical properties of locally
produced compost. They concluded that most of the
locally produced composts were immature. The
variability among the standards and compost quality
shows that there is a need for quality assurance
procedures and proper regulations to be applied in
order to convert waste to quality compost in KSA.
3. Modern approaches in waste
management practices
Municipal solid waste is considered as a significant
source of valuable products and energy. There are
enormous profits associated with solid waste and are
indisputable for countries such as KSA and Gulf region.
As the current practices in KSA are not very effective
for recovery of resources from solid waste, a few
initiatives at small scale have been taken in the
Eastern Province of Saudi Arabia (Ouda et al., 2013).
Waste to energy approach is emerging all around the
world. About 600 waste to energy facilities are
currently working in various parts of the world,
producing electricity and heat from 130 million tons of
waste (Young, 2010; Cheng, 2010). There are a
number of wastes to energy technologies available
such as incineration, gasification, pyrolysis, anaerobic
digestion and fermentation. Under the consideration
of waste composition and energy demand in KSA, the
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emphasis has been given to the technologies such as
anaerobic digestion and pyrolysis. The extensive food
consumption and wastage cause high organic content
in municipal solid waste for which anaerobic digestion
is most feasible technology. Similarly, pyrolysis is
efficient method for conversion of plastic waste to
liquid fuel, because plastic waste is the second largest
component of municipal solid waste due to high
consumption of disposable items especially in the holy
cities of Makkah and Madina where thousands of
pilgrims come every year from other countries. The
problems associated with current technologies and
overall advantages of shifting from old practices to the
new technologies are summarized in Fig. 3.
3.1. Anaerobic digestion: shifting from dumping to
engineered landfill systems
Recently, the attention has been increased towards
use of anaerobic digestion technology for treatment of
solid organic waste. This is due to the development of
new and strict regulations for safe disposal of organic
waste and need for alternative resources of energy to
depleting fossil fuels (Lettinga, 2001; Esposito et al.,
2012). Anaerobic digestion is defined as “the microbial
degradation and stabilization of organic materials
under oxygen free conditions, which leads to the
production of stable biomass and biogas (mixture of
H2, CO2 and CH4)’’ (Chen et al., 2008). It is highly
attractive for treatment of solid organic waste as it
provides an option of safe environmental disposal of
Municipal Solid Waste Management in KSA
Current Practices in KSA
Waste
Dumping Incineration Composting Land Settlement
GHG Emission Leachate
Ground water pollution
Required Energy
to run
Produce Energy
(Heat)
Fly Ash
Bottom Ash
Slow Process Only Organic waste
Treated
Organic fertilizers
Anaerobic Digestion Pyrolysis
Engineered Landfill Bioreactors Digestate
Catalytic Pyrolysis
Biogas
Thermal Pyrolysis
Biogas Un-used Land
utilization Large amount of
waste treated
Upgradation
(Pure CH4 production) Liquid Fuel
(Methanol)
Supply to
Industries
Electricity
Production
Electricity
Production
Transportation
Fuel
Liquid
Fuel
Gases
Char
Produce liquid fuel has
high quality.
Improve the economic of
process by reducing
temperature and
retention.
New Technologies Suggested Shifting to New
Technologies
(Eco-Friendly)
Shifting to New
Technologies
(Economical)
Figure 3: Shifting from ongoing to new technologies of solid waste management.
Anjum et al. 2016 J. Appl. Agri. Biotechnol. 2016 1(1): 13−26
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waste with additional economic benefits (Barton et al.,
2008).As the methane content of biogas is up to 70%
(Sheets et al., 2016), so it can be used as renewable
energy source which is inexpensive as compared to
the conventional fossil fuels. Moreover, energy
recovered from solid waste is environmentally safer,
as no additional GHG emissions are associated with
anaerobic digestion (Esposito et al., 2012).
In KSA, MSW is managed by a simple practice i.e.
collection and dumping into landfill. These landfills are
not an engineered landfill systems and lack leachate
and gas collection infrastructure, as observed in the
case of Makkah landfill site. The dumping of waste
into these landfills creates various problems such as
bad odors and leachate which may cause naissance
and ground water pollution. Further, due to anaerobic
degradation in landfill, the release of methane may
add extra global warming potential in the
environment. In 2009, it was observed in Europe that
the dumping of only 38% of total solid waste in landfill
has generated over 140 million tons of GHG emission
(measured as CO2 equivalent of CH4) (Eurostat, 2013).
This shows that, if the potential of anaerobic digestion
in landfill is not utilized for energy recovery, it may be
bad to the environment rather improving the
environmental quality. The landfill offers an
unmatched resource of energy in the form methane
gas, if this potential is utilized it can replace the
demand of fossil fuels and decrease CO2 emissions
(Starr et al., 2015).
KSA has the total area of 2,250,000 km² and most of
the land is fallow and desert. So, there is no scarcity of
land to use for development of landfill system. Given
the large amount of solid waste production every year
(Ouda et al., 2013), it is a worthwhile to examine the
potential of methane as a possible addition to the
current energy mix. The biogas produced during
anaerobic digestion cannot be used as a fuel in its
actual form. This is due to low calorific value of the
biogas (Al Mamun et al., 2015). Different technologies
are applied to get the full benefit of biogas and used
as a fuel. Some of the techniques such as biogas
upgradation and transformation of biogas to liquid
fuel (methanol) are described as follows.
3.1.1. Biogas up-gradation
The methane from anaerobic digestion does not
comes alone, it contains other gases such as carbon
dioxide, nitrogen, hydrogen sulfides etc. On an
average, the major portion of biogas contains CH4 and
CO2 which are present in the range of 30-70% and 15
50%, respectively (Dirkse, 2009; Petersson and
Wellinger, 2009). The calorific efficiency of biogas is
proportional to the concentration of CH4, more the
methane content more will be the calorific value and
vice versa. The presence of large volume of CO2
reduced the calorific value of biogas which leads to
the increased compression and transportation costs.
Therefore, minimizing the CO2 concentration is
necessary step to use full potential of methane for
fuel, electricity generation and heating purpose (Zhao
et al., 2010; Al Mamun et al., 2015; Starr et al., 2015).
The process of removing the CO2 to increase the
calorific value of biogas is called biogas up-gradation.
There is a high feasibility to use the upgraded biogas
as a fuel for vehicles or supply to the grid for
electricity generation. This option has been
implemented in more than a hundred cities around
the world (Petersson and Wellinger, 2009). Similar to
that, it can be opted in the big cities of KSA. There is a
huge demand of electricity and extensive amount of
solid waste is available. The energy demand in KSA is
55000 MW (Ouda et al., 2013) which is fulfilled by
fossil oil and natural gas. Biogas up-gradation provides
an opportunity to reduce the pressure on natural gas
and dependency on fossil fuels (Starr et al., 2015), if it
is integrated in landfill biogas system to get purified
methane gas. The upgraded biogas cannot substitute
natural gas consumption completely but can
contribute its share in overall energy production and
can decrease the pressure on depleting fossil fuel
resources.
There are various methods developed for up-
gradation of biogas, such as physical and chemical
adsorption, membrane based separation, pressure
swing adsorption, chemical and biological fixation of
CO2 and cryogenic separation, etc. (Farooq et al.,
2012; Abatzoglou and Boivin, 2009; Yang et al., 2008).
According to Starr et al. (2015) two widely applied
technologies are; high pressure water scrubbing and
chemical scrubbing with amine. These technologies
Anjum et al. 2016 J. Appl. Agri. Biotechnol. 2016 1(1): 13−26
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are based on absorption of CO2 using water and amine
solution (such as monoethanolamine), respectively, to
separate the CO2. The additional benefit of these
methods is that the captured CO2 can be regenerated
and sold to the industries, instead of releasing into
environment (Global CCS Institute, 2011; Parsons
Brinckerhoff, 2011). Al Mamun et al. (2015) found
that the water scrubbing system was efficient to purify
CH4 up to 100% in counter current flow water and gas.
Flow rate plays a crucial role in water scrubbing
system. The flow rate of water and gas as 0.465 and
1.8 m3/h can decrease the CO2 content by 93%.
Similarly, the water flow rate as 2 m3/h can remove
CO2 up to 87.6% (Shyam, 2002). In chemical
purification method of biogas, various solvents are
used such as mono-ethanolamine (MEA), tri-
ethanolamine, di-ethanolamine and aqueous solution
of alkaline (sodium, calcium) salts, etc. (Farooq et al.,
2012; Tippayawong and Thanompongchart, 2010).
New purification process i.e. treating biogas with
some purifying agent such CaO solution, solid CaO and
activated carbon can be applied for CO2 removal from
biogas at highly effective level. As mentioned, biogas
up-gradation methods are well studied, however,
there is a need to find out some viable and non-
expensive methods which can be integrated to landfill
to get high economic benefit of biogas (Al Mamun et
al., 2015).
3.1.2. Conversion of methane into liquid fuel
(methanol)
The biogas can be utilized as fuel using up-gradation
techniques, however, these process are usually
expensive and make the application of methane
uneconomical (Sheets et al., 2016). Similarly, other
problem associated with methane includes difficulties
to store and transportation because methane exists in
gaseous state at ambient temperature (Ge et al.,
2014). These issues can be resolved by converting
methane to methanol, which is a valuable product and
can be used as a liquid fuel by converting into olefins
and gasoline (Sheets et al., 2016).
Various methods have been reported for conversion of
methane to methanol, including thermo-chemical
(Riaz et al., 2013), biological conversion using
methanotrophs (Sheets et al., 2016), partial oxidation
(Krisnandi et al., 2015), and nonthermal plasmas
(Mahammadunnisa et al., 2015), etc. In
thermochemical process, methane can be efficiently
converted to methanol but the process is expensive
due to the requirement of metal catalysts and high
temperature up to 900 oC (Riaz et al., 2013).
Moreover, thermochemical process becomes
ineffective when impurities are present in the
methane biogas (Yang et al., 2014). Conversely,
biological conversion methods are more feasible and
environment friendly. Sheets et al. (2016) isolated a
new methnotroph that could use methane as a
substrate for its growth and multiplication. They
achieved 25% methane to methanol conversion in just
48 h.
In general, the selection of technology is very
important to use the potential of methane either by
up-gradation or conversion to methanol. Both have
their own benefits and potential as energy source. In
the case of KSA, there is a huge consumption of liquid
fuel in transportation. The methanol as a liquid fuel
can easily be handled and converted to other
petroleum fuels for its vast application such as
transportation.
3.2. Pyrolysis: converting plastic waste into liquid fuel
In KSA, municipal waste generation is 15.3 million tons
per year which contains 17.4 % plastic (Nizami et al.,
2015a). Plastic is non-biodegradable, hence it remains
in the environment for long period of time (Achilias et
al., 2007). Plastic waste mostly comprises of
polypropylene (PP), polystyrene (PS), low density
polyethylene (LDPE), polyvinyl chloride (PVC) and
polyethylene (PE). The disposal of these wastes by
landfill or incineration may cause environmental and
health problems (Ashworth et al., 2014). Likewise in
KSA, most of plastic wastes are disposed of with MSW
in landfill. Moreover, conventional recycling
techniques recycle only a small portion of plastic
waste. Under these circumstances, various waste to
energy techniques such as gasification and pyrolysis
are getting more attention of the researcher as an
alternative way for plastic waste treatment (Nizami et
al., 2015a).
Pyrolysis is a tertiary recycling techniques widely used
for thermal conversion of plastic waste at different
Anjum et al. 2016 J. Appl. Agri. Biotechnol. 2016 1(1): 13−26
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temperature ranges from 300oC to 900oC (Chen et al.,
2014). However, most of the researcher reported that
optimum temperature for pyrolysis was 450 oC to 550
oC (Miskolczi et al., 2009; Abbas-Abadi et al., 2014).
Plastic waste pyrolysis is carried out in the absence of
oxygen forming vapours and char (Sharma et al.,
2014). Vapours produced during pyrolysis are
converted into liquid fuel by condensation process.
The process takes about 3 to 4 hours to convert plastic
waste into liquid fuel (Fonts et al., 2009). The pyrolysis
process can be optimized by using catalyst to reduce
the temperature and retention time of process
(Miskolczi et al., 2009).
In pyrolysis technology, various kinds of pyrolytic
reactors were used by different researchers.
Generally, there are one-stage and two-stage pyrolysis
reactors. In one-stage reactor, catalyst is added with
the feedstock in the same reactor (Achilias et al.,
2007), while in two-stage reactor, the heating and
catalytic reactors are separated (Syamsiro et al.,
2014). On the basis of substrate feeding, there are two
types of reactor, which are pre-feeding (Lopez et al.,
2009) and post feeding, Moreover, on the basis of
design, there are various types of reactors like fixed
bed-reactor (Wang et al., 2006), rotary kiln reactor (Li
et al., 2005), tubular reactor (Marculescu et al., 2007)
and fluidized bed reactor (Al-Salem et al., 2010).
3.2.1. Value-added products of pyrolysis
Liquid fuel is the main energy product of pyrolysis.
Through pyrolysis, 74-84% plastic (by weight) can be
converted into liquid fuel (William, 2006; Lopez et al.,
2011). Liquid fuel produced from pyrolysis having
nearly same values to that of diesel in terms of
density, viscosity, high heating value (HHV), cold flow
properties, etc. Thus, it has huge potential to be used
as an alternative of conventional diesel. Research on
characterization of pyrolytic liquid fuel showed that
the produced fuel has 0.79-0.87 g cm-3 of density 1-
2.96 mm2/s of viscosity and -18 oC as cold flow
property (Syamsiro et al., 2014; Wongkhorsub and
Chindaprasert, 2013; Isioma et al., 2013). Viscosity is
an important fuel characteristic and depends on the
feedstock composition. Generally, PS produces less
viscous oil as compared to PE and PP, which has
complex branched hydrocarbons (Siddique and
Redhwi, 2007). Moreover, less cold flow properties
makes it more favorable to be used in those parts of
the world where temperature remains very low
throughout the year. In addition, the liquid fuel
produced from PS, HDPE, LDPE and mix plastic has
HHV ranging between 45.86, 3839, 44.4 MJ/kg
respectively (Sharma et al., 2014; Panda et al., 2010;
Kim et al., 2010).
Char is an unburnt plastic which left over in the
reactor after completion of pyrolysis process. It is a by-
product of the process and can be used as adsorbent
in wastewater treatment. Char adsorption values can
be increased by thermal activation at temperatures of
900 oC for 3 hours. Activation increases its BET surface
area from 10.83 m2/g to 16.77 m2/g, reduces the pore
size (521.30 oA to 496.00 oA) and increases pore
volume (0.1441 cm3/g to 0.2080 cm3/g) (Jindaporn and
Lertsatitthanakorn, 2014). Char with high BET surface
area, pore volume and less pore size has the potential
to be used as adsorbent in different environmental
applications such as removal of heavy metals from
wastewater (Heras et al., 2014). Moreover, the char
produced from PS and HDPE has HHV of 36.29 and
23.04 MJ/kg, have potential to be used as alternative
source of energy (Syamsiro et al., 2013).
Gases produced from pyrolysis are comprised of CO,
CO2, CH4 and H2, while PVC plastic also produces
chlorine gas (Lopez et al., 2011). The use of catalyst
having high BET surface area increases the gases
production during pyrolysis process. Moreover, gases
produced from catalytic pyrolysis have 45.9 - 46.6
MJ/kg HHV, which show that it has potential to be
used as alternative of natural gas (Miskolczi et al.,
2009).
3.2.2. Catalytic pyrolysis: emphasis on Saudi Arabian
natural zeolite
Catalytic pyrolysis is a prominent technique to convert
plastic into high quality liquid fuel and other value-
added products, such as char and gases. Catalyst
enhances the efficiency of pyrolysis process by
lowering the temperature and retention time (Manos
et al., 2002), removing impurities and converting
hydrocarbon into gasoline (Lopez et al., 2011). The use
of catalyst makes the process highly economical and
also improves the quality of the liquid fuel. Catalysts
Anjum et al. 2016 J. Appl. Agri. Biotechnol. 2016 1(1): 13−26
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Copyright© PMAS-Arid Agriculture University Rawalpindi, Pakistan http://jaab.uaar.edu.pk
used for pyrolysis process are acidic in nature
(Jindaporn and Lertsatitthanakorn, 2014). Most
frequently used catalysts are ZSM-5 (Lopez et al.,
2011), HZSM-5 (Miskolczi et al., 2009), FCC (Achilias et
al., 2007), Red mud (Lopez et al., 2012), Natural zeolite
(NZ) (Syamsiro et al., 2014), etc. In Kingdom of Saudi
Arabia (KSA) NZ is found in abundance in the area of
Harrat Shama and Jabbal Shama (Nizami et al., 2015b).
It has high BET surface area with crystalline structure
and has potential to be used as catalyst in different
waste to energy field. In general, the use of Saudi
Arabian natural zeolite could be an excellent option
for enhancing the efficiency of pyrolysis process for
treatment of huge amount of plastic waste. The use of
NZ will not only improve the liquid fuel quality but also
make the process highly economical due to local
abundance.
In order to improve the catalytic activity of catalyst,
there are different modification techniques available
by which the catalytic efficiency of natural zeolites can
also be increased. Modification can be carried out by
thermal activation (Syamsiro et al., 2014), acid
leaching (Sriningsih et al., 2014) and doping of metal
via wet impregnation (Adnan and Jan, 2014). Thermal
activation of catalyst at 550 oC removes the volatile
compounds from the catalyst (Syamsiro et al., 2014)
while acid leaching increases acidity of catalyst and
removes internal impurities of the catalyst. Likewise,
catalyst can be modified by doping of metals, such as
Ni, Co, Mo, Zn, etc. Presence of metal sites can
accelerate hydrogenation and dehydrogenation
reactions (Panda et al., 2010). Hence, dual functions
make it more prominent to be used as catalyst in the
catalytic pyrolysis (Ciobanu et al., 2008).
4. Conclusion
KSA has a high potential to recover the resources from
huge amount of solid waste generated in the country.
The current practices of municipal solid waste in KSA
are not very effective, thus shifting toward new
approaches of resource recovery not only provides
environmental safety, but also add the value in the
economy in terms of energy and value added
products.
The major portion of municipal solid waste is organic
(40%), thus the anaerobic digestion process is highly
feasible to recover methane as an energy resource.
For this purpose, there is a need to develop new
landfill systems which should be properly designed,
engineered, and managed. This could be an effective
alternative to current practice of uncontrolled waste
dumping system, where no gas recovery systems are
available. To get the full potential of methane biogas,
the landfill system should be equipped with gas
collection and further integrated with biogas up-
gradation system to get methane with high calorific
value.
As plastic waste is the second largest proportion of
municipal solid waste, initiative should be taken for
proper segregation and recycling this waste. The other
ways include the use of pyrolysis technology which has
capability to convert any type plastic into fuel oil. To
get high quality fuel oil, catalytic pyrolysis is an
effective method, where the use of natural zeolite as a
catalyst could be beneficial from economic point as
zeolite is abundantly available in KSA.
There is a huge potential of using waste as a resource,
yet there is a need to improve the existing strategic
planning regarding waste management, especially in
big cities of KSA accommodating most of the country
population.
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... In other work, Anjum et al. (2016) reported that the anaerobic digestion can be used to treat the organic part of municipal solid waste. Therefore, the methane produced during the process can be used as fuel [16]. On the other hand, Balla et al. (2016) reported that energy generated from biodegradable municipal solid waste is the most appropriate process to reduce greenhouse gas emissions [17]. ...
... Pujaraa et al. (2019) [11] concluded that there are four main reaction stages occurs in the composting process: However, the biggest challenge with this method is the survival of microorganisms in ideal ecological conditions, and therefore low-quality compost has a negative effect on soil properties and plant growth Anjum et al. (2016) [16]. Apart from the conventional methods for preparing the compost, some advanced techniques of composting have been developed such as Bangalore method, Indore method and Coimbatore method Misra et al. (2003) [36]: (a) Bangalore method : Organic residues and night soil are placed in alternate layers. ...
... In order to assess the quality of compost, many private and official authorities have established standards and regulations to check the quality of compost for agricultural applications and environmental protection. According to GCST,2006 ( as a cited Anjum et al. (2016) [16] some arab gulf countries have also documented regulations on the quality of imported and local organic compost. ...
Article
Full-text available
Jordan has been facing a wide variety of sudden changes in humanitarian issues (population growth, industrialization rapid, urbanization process, influx of refugees to Jordan etc.). These unexpected changes forced people to make quick reactions to adapt and settle, which resulted in further generation of solid waste which normally was dumped in landfills and caused contamination of soil, water and air. Solid Waste Management (SWM) has been an integral part of every human society. Improper SWM accelerates natural resources degradation and has a great impact on climate change and the quality of life of citizens. Hence, in this paper, we highlight the environmental and health problems of the Al-Akaider landfill in Jordan. We propose a multi-pronged integrated approach to improve solid waste management at the Al Ekaider landfill. In keeping with this approach, a general action plan has been proposed that could be tailored to recycle Organic Waste (OW) to produce biogas and compost.
... Hajj study was conducted in April, 2013, midway between the two Hajj campaigns (Fig. 7e) (Fig. 7b). It receives several thousand tons of solid waste on normal days, primarily organic waste and plastics (Anjum et al. 2016). Because it is used to dump waste and does not have leachate or gas collection infrastructure, it is technically a non-engineered landfill (Anjum et al. 2016). ...
... It receives several thousand tons of solid waste on normal days, primarily organic waste and plastics (Anjum et al. 2016). Because it is used to dump waste and does not have leachate or gas collection infrastructure, it is technically a non-engineered landfill (Anjum et al. 2016). Five air samples were collected from an unexpected fire at the Mecca landfill on May 13, 2013 (Fig. 7e, f). ...
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Environmental context The production and consumption of chlorofluorocarbons (CFCs) is regulated under the Montreal Protocol and its amendments, due to their role in stratospheric ozone depletion. Global atmospheric levels of CFC-11 did not decline as rapidly as expected during 2012–2018, in large part due to emissions from eastern China. In order to further clarify global CFC-11 emissions, this work provides a rare set CFC-11 measurements from understudied countries and sources throughout Asia (1998–2018). Abstract Trichlorofluoromethane (CFC-11) is an ozone-depleting substance whose production and consumption are regulated under the Montreal Protocol. Global atmospheric CFC-11 levels declined less quickly than expected during 2012–2018, largely because of ongoing emissions from eastern Asia. Satellite measurements suggest additional CFC-11 hotspots in the Arabian Peninsula and north India/Nepal. Here we present CFC-11 levels measured in dozens of Asian cities during 1998–2018, including China and Pakistan before the 2010 phaseout of CFC-11, and China, Nepal, Pakistan, Saudi Arabia and South Korea after the phaseout. Surface measurements of CFCs in Nepal, Pakistan and Saudi Arabia are very rare, and these surveys provide important observational constraints from understudied regions. During pre-phaseout campaigns, higher CFC-11 levels were measured in Beijing than Karachi, despite much higher overall volatile organic compound (VOC) levels in Karachi. During post-phaseout campaigns, average CFC-11 levels were higher in inland Shandong Province and Seoul (1.11–1.23× background) than in western Saudi Arabia, Lahore and Kathmandu (1.02–1.11× background), despite higher levels of other VOCs in the latter regions. While China is known to emit excess CFC-11, elevated CFC-11 levels in Seoul, especially during stagnant meteorological conditions, suggest local emissions in 2015–2016. Rough emission estimates suggest that South Korea is likely a relatively minor global source of excess CFC-11. Hotspot CFC-11 levels were measured from a landfill fire in Mecca (average of 1.8× background) and from garbage burning in Nepal (1.5× background). Because garbage burning and open burning in dumps are common practices, further investigation of CFC-11 emissions at dumps and landfills worldwide is encouraged to determine their global impact.
... One-third of all food produced globally is wasted in the food chain, indicating the environmental impact if correct treatment is not provided; also, technology can make such a high amount of food waste useful [20]. Generally, food waste is disposed of in open landfills [112], and it has a high proportion of carbohydrates, proteins, and fats, making it a good option for usage as a raw material for composting [20]. Food waste increases as the world's population grow, and changing eating habits, adoption patterns, and food culture could be contributing factors [113]. ...
Article
decades. Studies revealed that by 2050, global solid waste generation is expected to reach 70% to 3.4 billion metric tons. Thus, the authorities urgently need to provide a low-cost, efficient technology for treating waste disposal. However, it is evident that only 20% of waste is recycled, and the remaining is still being considered for landfilling. In developing countries, the generated waste is simply disposed of in an open area, which causes a severe threat to humans, animals, and the environment. To date, organic waste and fourth-generation biomass have been investigated for multiple targeted products. Thus, the present review article highlights the emerging problems in organic waste generation, management, and converting them into various value-added bioproducts. This review also deals with the conversion of multiple biofuels such as liquid, solid, gaseous, and bioelectricity from organic waste resources. Besides, the latest approaches in organic waste are also detailly addressed for the production of value-added bioproducts such as bioplastic, bio-compost, and organic acids. Furthermore, the techno-economic analysis (TEA) and life cycle assessment (LCA) of organic waste is also explored. The transformation of organic waste to value-added bioproducts enhances the circular bioeconomy approach by reducing waste, increasing energy production, and other healthcare products. Finally, it is concluded that the utilization of organic waste to value-added bioproducts and biofuels production will be helpful in achieving high energy security, environmental protection, as well as enhancing the bioeconomy perspective.
... With 17.4%, plastic is the second most abundant waste type found in municipal solid waste in the larger Saudi Arabian cities. Only 15-20% of the plastic wastes are recycled, and the majority ends in landfills (Anjum et al., 2016). As larger Saudi Arabian cities such as Jeddah and Jazan lie on the Red Sea, here, a larger influx of plastic wastes into the Red Sea would be expected, but again exact data are lacking. ...
Article
Microplastics are omnipresent in the marine environment. Their bioaccumulation in fish and other marine biota is a concern due to the potential human health risks from exposure through seafood sold in markets. There is a global effort afoot to take inventory of microplastic contamination in the world’s main water bodies. This includes an understanding of the sources, the trophic transfer and the fate of microplastics in aquatic systems. Studies on the state of microplastic pollution in the Red Sea have appeared only in the last 5 years. Nevertheless, they gave insight into the abundance of microplastic particles within the marine environment of the Red Sea. The following is a review of these studies.
... The UAE also had experienced high rates of population growth in the past few decades, which comes along with rapid urbanization; combined with the inadequate waste management practices resulting in poor disposal of waste (Almansoori and Moussa, 2017;Ghayebzadeh et al., 2020). In a study that reviewed the solid waste management practices in Saudi Arabia, it was found that the prevailing method of waste management is simply collecting the waste and dumping it in non-engineered landfills where there is a high risk of leaching and release of gases (Miandad et al., 2016). There seems to be a trend of inadequate waste management in most of the countries in the Arabian Gulf region, slightly varying depending on the population number, waste generation rates and rate of development. ...
Article
Global plastic waste production has increased dramatically in recent years, both globally and regionally, having a multitude of adverse effects on the environment and human health. However, little attention has been directed to this problem in the Arabian Gulf region. This study aims to delineate and map the status of the plastic waste problem in the Gulf Co-operation Countries (GCC), with a focus on Qatar. The study focuses on the plastic waste in the marine environment, depicting the different types, sizes and shapes of plastic particles found in the Arabian Gulf. To depict the flow of plastic waste, a generic material flow diagram was built using a material flow analysis software named STAN, in which transfer coefficients were assigned based on existing scientific literature and estimations built on data from local industries and recycling facilities. The recovery and recycling efforts that have been made by the different GCC countries, in efforts to reduce plastic waste and minimize the risk of plastic on the environment are analyzed, too. Our analyses indicate that approximately 11.9 Mt ± 595.395 Kt of plastic waste is produced annually in the GCC region, of which only 23 ± 15% is recycled, indicating that improvements are yet to be made in the recovery, recycling and treatment of plastics in the region. However, in Qatar, a higher percentage of plastics (40 ± 10%) is recovered-recycled with efforts to treat plastics and reuse it to generate energy.
... The generated waste in Saudi Arabia is regulated by the Local Affairs and Ministry of Municipalities by collecting and dumbing waste in open landfills or by combustion. However, disposing waste without treatment has huge environmental concerns because plastic waste that is recycled in Saudi Arabia is only 15-20% (Muzammil et al., 2016). In Bahrain, a study was carried out by Mohammed Saleh AL Ansari (Mohammed, 2012), on solid waste management. ...
Article
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Due to the adverse effect of energy production from traditional fossil fuels, the move towards renewable and sustainable energy has become imperative. The waste disposal sector offers hope towards environmental sustainability and potential to generate strong income for any economy. The region of the Gulf Cooperation Council (GCC) member countries in the Middle East generates the highest quantity of municipal waste per capita, compared globally to other countries. In the GCC region, waste is usually just dumped at different landfill stations. Effective waste management is imperative for environmental protection and sustainable development. This paper presents a review of the sustainable waste management strategies in Oman, in line with the United Nations goal on environmental management of waste. The current waste management strategies in Oman were discussed, and various Waste-to-Energy (WTE) technologies were proposed. These proposed WTE strategies would help in effective waste management in Oman and also in increasing the power grid capability. The salient part of this paper is an overview of the ability of using landfill leachate as feedstock to produce clean and green hydrogen gas considering different photo-fermentation processes. Production of hydrogen using single photo-fermentation process considering; landfill leachate alone, with leachate and addition of inoculum such as sewage sludge, and with substrate such as sucrose, glucose and landfill leachate utilizing batch bio-reactor and anaerobic conditions at controlled temperature, different initial pH, and heat treatment temperature range. Furthermore, a prototype model for the optimization of the inoculum size and the substrate was proposed considering 2-level factorial design using design expert. The data gathering of this paper was carried out by investigating the different regions in Oman having the lowest and highest waste produce, the average annual waste for the different governorates and the total amount of waste for five consecutive years (2015 to 2020), for the various engineered landfills. The cost of managing waste in the different governorates of Oman was presented, considering the average annual waste produced, in various regions of the country for the duration of the study. More so, some challenges and opportunities in carrying out effective waste management in Oman were addressed.
... The UAE also had experienced high rates of population growth in the past few decades, which comes along with rapid urbanization; combined with the inadequate waste management practices resulting in poor disposal of waste (Almansoori and Moussa, 2017;Ghayebzadeh et al., 2020). In a study that reviewed the solid waste management practices in Saudi Arabia, it was found that the prevailing method of waste management is simply collecting the waste and dumping it in non-engineered landfills where there is a high risk of leaching and release of gases (Miandad et al., 2016). There seems to be a trend of inadequate waste management in most of the countries in the Arabian Gulf region, slightly varying depending on the population number, waste generation rates and rate of development. ...
Conference Paper
As the population continues to grow, the generation of waste and specifically plastic waste, has also increased significantly in the past decades both globally and regionally. However, little attention has been directed to this problem in the region. This study aims to delineate and map the status of the plastic waste problem in Qatar with a focus on the plastic inflow to the marine environment. A generic material flow diagram was built using a material flow analysis software named STAN, to depict the flow of the plastic waste. The study focuses on the plastic waste in the marine environment, depicting the different types, sizes and shapes of plastic particles, and the recovery and recycling efforts that have been made, in order to reduce plastic waste and minimize its risk on the environment.
Article
This work aims to prepare and characterize the hydroxyapatite (HAP) nanomaterials from marble wastes (the utilization of the building marble waste for reducing the environmental pollution hazards) and to study its capabilities as antimicrobial and antifungal agents of the prepared nanoparticle. The utilization of the marble waste as a source for calcium chloride and to be reacted with sodium hydrogen phosphate, for synthetization of hydroxyapatite nanoparticles, the prepared material is characterized, tested, and analyzed using X-ray diffraction (XRD), Scan Electron Microscope (SEM) with Energy Dispersive X-Ray analysis (EDAX) techniques. The antimicrobial activity of prepared hydroxyapatite nanomaterial is tested using a well diffusion method with different types of bacteria (Gram-negative): Escherichia. Coli, Salmonella paratyphi, Pseudomonas earuginosa, and Alcaligenes aquatilis and bacteria (Gram- positive): Staphylococcus aureus, and Streptococcacea pneumonia. The antifungal efficacy of HAP nanoparticles is tested for different species of Aspergillus niger, Aspergillus flavus, and Penicillium SP. The diameter of the inhibitory zone shows the sensitivity of the microorganism to HAP nanoparticles in a greater inhibition against Gram- positive Staphylococcus aureus and Streptococcacea pneumonia, at 100% DMSO concentration. The diameter of the inhibition zone was 03.70 mm, when compared with other types of bacteria. The diameter of the inhibitory zone showed the sensitivity of the microorganism to HAP nanoparticles in a greater inhibition against Penicillium SP at 100% DMSO concentration, the inhibition zone diameter was 2.20 mm, when compared with other Aspergillus niger and Aspergillus flavus fungal species. Based on obtained results for the HAP nanoparticles prepared from the marble wastes have antibacterial effects on both Gram-negative (E. coli) and Gram-positive (S. aureus) strains.
Article
Jordan has been facing a wide variety of sudden changes in humanitarian issues (population growth, industrialization rapid, urbanization process, influx of refugees to Jordan etc.). These unexpected changes forced people to make quick reactions to adapt and settle, which resulted in further generation of solid waste which normally was dumped in landfills and caused contamination of soil, water and air. Solid Waste Management (SWM) has been an integral part of every human society. Improper SWM accelerates natural resources degradation and has a great impact on climate change and the quality of life of citizens. Hence, in this paper, we highlight the environmental and health problems of the Al-Akaider landfill in Jordan. We propose a multi-pronged integrated approach to improve solid waste management at the Al Ekaider landfill. In keeping with this approach, a general action plan has been proposed that could be tailored to recycle Organic Waste (OW) to produce biogas and compost. © 2018 JASET, International Scholars and Researchers Association
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Chemical properties of twenty five composts produced in Saudi Arabia were investigated in order to evaluate their quality compared to local and international standards of compost quality. Generally results showed large variations between most chemical properties of composts under the study. Electrical conductivity (EC) Ec of final composts ranged from 0.6 dSm-1 to 25.4 dSm-1 and 92% of studied composts exceeded the upper limit of accepted EC set by CCQC and PAS-100. Most pH values tended to be alkaline and % were higher than 7.5. Ammonium contents were more than 500 mgkg-1 (the maximum limit set by CCQC) in 40% of final products of compost, which may inhibit seed germination. Organic matter percentages were less than 25% (CCQC minimum limit) in 7% of composts and less than 40% (GCST minimum limit) in 76% of composts. Most C/N ratios (92%) of composts were less than 20% and complied with CCQC, GSCT standards. Nitrification index of 13 composts (52%) was above 3 and they are considered immature composts according to CCQC standards. Significant differences were shown between means of some chemical characteristics of all types of composts. Heavy metal contents of composts were below the upper limit set by CCQC and GCST with exception of Ni and Cd, which exceeded the allowable limit in 65% of and 79% respectively. In general, results showed that most local compost facilities are unable to produce a mature composts product. The high variability between chemical properties of composts confirmed the need for establishing quality assurance procedures to be applied by suitable mechanisms to produce mature compost and protect public health and the environment. Copyright © Ahmad Al-Turki, et al., This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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Energy recovery from waste is not a new field of study, but its implementation continues to be a challenge in some Arab countries. Although there is abundance of useful waste in the urban markets, practices aiming at waste to energy conversion are still negligible. In the kingdom of Saudi Arabia, so-called green markets are abundant with renewable energy potential, but the practical implementation of this potential is missing. Therefore the objective of this paper is the evaluation of waste generation in KSA for the energy recovery purpose, and to show that the conversion of green waste into biofuel is not only environmentally friendly but also financially rewarding. Since the result illustrate that the major portion of the waste generated is organic waste, anaerobic digestion is proposed waste to energy technology because of its feasibility for biodegradation of moist organic wastes into biogas. Diversion of waste into biogas and bio-fertilizer will ensure that it is treated in such a way that it becomes a useful product instead of harmful one. Furthermore as the policy makers and planners in renewable energy sector have intended for kingdom of Saudi Arabia to be andquot;kingdom of sustainable energyandquot; as well, hence they are needed to give special attention toward the largest Saudi Arabia's green market and should invest more to implement this plan.
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Municipal Solid Waste (MSW) management is a chronic environmental problem in most of the developing countries, including the Kingdom of Saudi Arabia (KSA). The concept of Waste-to-Energy (WTE) is known as one of the several technologies capable of benefiting a society, which desires to reduce fossil-fuel addiction. Currently, there is no WTE facility existing in the KSA. The MSW is collected and disposed in landfills untreated. A substantial increase in the population by 3.4 %/y over the last 35 y coupled with urbanization and raised living standards have resulted in high generation rate of MSW. In 2014, about 15.3 Mt of MSW was generated in KSA. The food and plastic waste are the two main waste streams, which covers 70 % of the total MSW. The waste is highly organic (up to 72 %) in nature and food waste covers 50.6 % of it. An estimated electricity potential of 2.99 TWh can be generated annually, if all of the food waste is utilized in anaerobic digestion (AD) facilities. Similarly, 1.03 and 1.55 TWh electricity can be produced annually if all of the plastics and other mixed waste are processed in the pyrolysis and refuse derived fuel (RDF) technologies respectively. The aim of this paper is to review the prospective WTE technologies in Saudi Arabia. However, the real selection of the conversion technologies will be done in conjunction with the fieldwork on waste characterization and laboratory examination of selected technologies and further socio-economic and environmental evaluations.
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Basis Economic Cases Logical Approach for Future Progress References
Article
The aim of this work was to isolate methanotrophs (methane oxidizing bacteria) that can directly convert biogas produced at a commercial anaerobic digestion (AD) facility to methanol. A methanotrophic bacterium was isolated from solid-state anaerobic digestate. The isolate had characteristics comparable to obligate methanotrophs from the genus Methylocaldum. This newly isolated methanotroph grew on biogas or purified CH4 and successfully converted biogas from AD to methanol. Methanol production was achieved using several methanol dehydrogenase (MDH) inhibitors and formate as an electron donor. The isolate also produced methanol using phosphate with no electron donor or using formate with no MDH inhibitor. The maximum methanol concentration (0.43±0.00gL-1) and 48-h CH4 to methanol conversion (25.5±1.1%) were achieved using biogas as substrate and a growth medium containing 50mM phosphate and 80mM formate.