J.Env.Sci. Tech., Winter 2009, No.39 Special issue
Energy
optimization in gas-to-liquid process
Majid Amidpour1
Mohammad Hasan Panjeshahi2
Malek Shariati Niassar3(Corresponding author)
1-Faculty of Mechanical Engineering, K.N.T. Industrial University
2-Faculty of Engineering, Tehran University
3-Faculty of Energy and Environment, Science and Research Branch, Islamic Azad University
Abstract
In GTL process
-- the conversion of gas to liquid products -- a great amount of energy is
released. Meanwhile, the various warm and cool streams in this process with
their significant temperature difference can internally supply the required
energy of the system. In fact, the GTL process has the potential to produce a considerable
amount of energy far beyond its needs. The excess energy is so much that it can
even run a power plant. In other words, the process of converting natural gas
to liquid hydrocarbons not only is self-sufficient from an energy point of the
view, but also can produce energy. In this paper, various approaches to energy
optimization in a GTL unit with a capacity of 10,000 BPD are studied using
optimizer software at different stages of the process. Then, the most suitable
method is selected and the amount of the generated energy is calculated and
reported. Finally, an integrated network of heat exchangers is suggested.
Key words: GTL, synthesis
gas, Fischer, integrated network
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
Recycling the PET and PP used in
packaging industries to produce isolating panels and
assess their compressive strength
Zeinolabedin Gh. Alamdari1(Corresponding author)
Ali Khavanin1
Mehrdad Kokabi2
1-Faculty of Medicine, Tarbiat Modarres University
2-Faculty of Engineering, Tarbiat Modarres University
Abstract
Due to their
suitable strength against mechanical impacts and also their economic advantage as
compared with other packaging materials, polymeric products are increasingly
used in different industries. One of the problems with the use of plastic
materials is that their non-decomposition may have negative effects on the
environment. One of the aims of the present study is to find an economical
method for recycling plastic packaging materials and to change them into
isolators with a higher added value than traditional recycling methods.
In this
research, the samples were prepared from PET and PP packaging materials; the mesh
sizes were 1 to 5 mm and 6 to 20 mm with equal weights. The researcher used polyester
fibers (2.5% of the total weight of the polymeric materials). They also applied
polyvinyl acetate (20 % of the weight of the polymers) as the composite binder.
To prepare the final mixture, the mentioned materials were mixed at three stages
and molded three times.
After being
prepared, the samples were tested with INSTRON device at the speed of 20 mm / min.
The researchers measured the compressive strength of PET and polyester fiber
samples, of samples produced from PET and PP combined, and of polyester fibers
with 1 to 5 mm particle mesh size. The results indicated that the mean
variation of sample length due to compression in 10, 20, 30, 40 mm of PET and polyester
fiber samples required 1.2, 10.8, 18.6, 31.9 % more pressing force load
compared with the sample produced from PET and PP. Meanwhile, the compressive
force of PET was compared with that of polyester fiber samples with PET and PP and
polyester fibers combined with 6-to-20-mm particles mesh size. The findings showed
that in length variation of 20, 30, and 40 mm, samples made with PET and PP
needed more load force (4.5, 14, 25.3 %) compared with PET and polyester fibers
made with PET angiopolyester fibers. Also, the results of the t-test for a comparison
of means showed that the mean difference with α=0.05 for samples made with PET and PP combined
in 10,20,30 and 40 m variation in the length of two-groups samples wass
significant .
Key words: Plastic
recycling, PET & PP, isolating panel, compressive strength
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
The performance of chemical compounds (Ferro sulfate, ferric chloride and
calcium hypochlorite) in H2S and sulfide removal
from industrial effluents
Ali Torabian1
Amir Hesam Hassani2(Corresponding author)
Leili Shafiee2
1-Faculity of Environment, University of Tehran
2-Faculty of Environment, Science and Research Branch, Islamic Azad University
Abstract
In this research, the performance of three
chemical compounds (Ferro sulfate, ferric chloride and calcium hypochlorite)
and the effect of an increase of TDS on them in sulfide removal have been studied.
The results showed that using these three chemical materials, chemical precipitation was a proper method for effluent treatment. With the change of pH from 4 to 9 under the concentration limit of sulfide 0.95-47.05 mg/l and following the study of 97 effluent samples, the highest sulfide removal efficiency of nearly 61.38-66.21% was observed in a pH of 7. Besides, after checking 59 effluent samples, Ferro sulfate with the concentration of 2-100 mg/l under the concentration limit of sulfide 0.95-47.05 mg/l had the highest sulfide removal efficiency of about 55.79-73.94%. Moreover, after studying 62 effluent samples, Ferric chloride with the concentration of 2-100 mg/l under the concentration limit of sulfide 0.95-47.05 mg/l had the sulfide removal efficiency of nearly 67.5-84.2%. Furthermore, Calcium hypochlorite with the concentration 10-500 mg/l under the concentration limit of sulfide (0.95-47.05 mg/l) and with checking 60 effluent samples had the sulfide removal efficiency of about 62.17-80.85%. It can be seen that the ratios of ferric, Ferro and hypochlorite ions to the sulfide ion are 2, 5 and 10, respectively and that Ferric chloride has the highest removal efficiency with less concentration. Finally, the results have shown that the decrease in the removal percentages of Ferro sulfate, Ferric chloride and Calcium hypochlorite by increasing TDS to 1000 mg/l was not significant while with the increase of TDS up to 1500 mg/l, sulfide removal efficiency is considerable.
Key words: Ferro sulfate, ferric
chloride and calcium hypochlorite, hydrogen sulfide, chemical precipitation.
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
Sanitary-technical
assessment of extracting
methane from the landfill in Shiraz
Ghasem Ali Omrani1
Narges Mohseni2(Corresponding author)
Kazem Haghighat3
Amir Hossein Javid2
1-School of Public Health, Tehran University of Medical Sciences
2-Faculty of Energy and Environment, Science and Research Branch, Islamic Azad University
3-Executive Deputy of City Services at Shiraz Minucipality
Abstract
Nowadays, wastes are known as environmental pollutants which can threaten people’s health if we don’t try to reduce them. Landfills play an important role in the network of solid waste disposal, and therefore, are considered an integral part of the new strategy of integrated solid waste management.
In recent years, the design of a landfill has included the equipment for the control and transmission of gas and the use of energy of biogas.
The landfill gas (LFG) is obtained through a number of bio-chemical reactions on degradable organic compounds in anaerobic conditions. These gases include methane, carbon dioxide, hydrogen, hydrogen sulfide, volatile organic compounds, and so on.
The assessment of gas generation rate and its emission from the landfill is of great importance in designing such sites and the successful use of the produced gases as sources of energy.
After extraction and treatment, gases generated in the landfill are used for the production of the energy needed in industry.
In this study, the emission of gases and pollutants from Shiraz landfill is investigated using the software package of "Land GEM" Sensitivity analysis with different values for k (rate of degradation) was conducted on them. The results showed that the amounts of methane and carbon dioxide were 1.5*106 m3/y and 9.6*105 m3/y , respectively. Besides, the highest quantity of methane generation is estimated for the solar year of 1400.
Key words:
Methane, landfill, technical, sanitary, Shiraz
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
The study of sorption equilibrium of
chromium (VI) from aqueous solutions using rice
bran
Mahboobeh Nameni1
Mohammad Reza Alavi Moghadam1(Corresponding author)
Mokhtar Arami2
1-Faculty of Environment and Civil Engineeringt, Amirkabir University of Technology (AUT)
2-Faculty of Textile Engineering, Amirkabir University of Technology (AUT)
Abstract
In this research, the adsorption of Cr (VI) ions on
rice bran has been studied using batch adsorption techniques. The main objectives of this study are 1) to investigate the chromium
adsorption from aqueous solution by rice bran, 2) to study the effect of
experimental conditions -- such as pH, contact time and initial chromium
concentration -- on adsorption process performance and 3) to determine
appropriate adsorption isotherm and kinetics parameters of Cr (VI) adsorption
on rice bran.
The results
showed that adsorption of chromium by rice bran reached equilibrium after 120
minutes and following this time a little change was observed in the efficiency
of chromium removal. Higher chromium adsorption was observed in lower pHs and
maximum chromium removal (99.8%) was obtained in the pH of 2 for an initial
concentration of 5 mg/l. Adsorption decreased with an increase in the initial
chromium concentration. The obtained results also revealed that among 6 studied
isotherm models (Langmuir, Freundlich, BET, Temkin, D-R and generalized
adsorption models), the adsorption of chromium (VI) by rice bran followed Frendlich isotherm
equation with a correlation coefficient of 0.997. The maximum monolayer
adsorption capacity was determined to be 0.208 mg/g for the experimental
conditions of the present study. In addition, the kinetic order of the adsorption of
chromium by the studied adsorbent follows a pseudo-first order rate with
a high correlation factor (R2 ≥ 0.99) at 25◦C. The results indicate that
rice bran can be used as a low-cost alternative to commercial adsorbents in the
removal of Cr (VI) from water and wastewater.
Key words: Adsorption, chromium (VI), rice bran, adsorption
isotherm, adsorption kinetics
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
Biosorption of
Pb (II) and Zn (II) by the non-living biomass Phanerochaete chrysosporium
Reza Marandi1
Hamideh Amir Afshar2 (Corresponding author)
1-Faculty of Technology, Tehran North Branch, Islamic Azad University
2-Faculty of Chemistry, Tehran North Branch, Islamic Azad University
Abstract
Biosorption of
heavy metals can be an effective process for the removal of heavy metal ions
from aqueous solutions. In this study, the removal of Pb (II) and Zn (II) by
dead cells of a lignolytic white-rotfungs, Phanerochaete chrysosporium, was
investigated. In addition, the effect of pretreatment of P.chrysosporium
biomass on biosorption of Pb (II) and Zn (II) was studied. Pretreated
P.chrysosoporium has been used for biosorption of metals in this study. Here,
the adsorption technique has been done in Batch system. The effects of the
initial metal ion concentration, initial pH, stirring speed and contact time on
biosorption efficiency were studied. The surface change density of the
biosorbents varied with the pH of the medium and the maximum biosorption of
heavy metal ions on the biosorbents was obtained between Ph 5 and 6.
The Biosorption
of Pb (II) and Zn (II) on the biosorbents increased as the initial
concentration of Pb (II) and Zn (II) ions were increased in the medium.
Biosorption equilibrium was established about 1 h, the adsorbed heavy metal ion
did not significantly change further with time. The maximum heavy metal ions
adsorbed was found to be 90 and 63 mg/g dry biomass P.chrysosporium for Pb (II)
and Zn (II), respectively.
The results
indicated that increasing the temperature led to an increase in the adsorption
rate. The experimental adsorption data were fitted to the Langmuir and
Freundlich adsorption models. The affinity order of heavy metal ions showed Pb
(II)>Zn (II). The biomass was regenerated by washing with a 50 mM solution
of HCI. The desorption efficiency was as high as 98%. The results suggested
that P.chrysosporium could be used as a biosorbent for an efficient removal of
heacy metal ions from aqueous solution.
Key words: Biosorption, adsorption,
heavy metals, preteatment, biosorbent, biomass, P.chrysosoporium
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
Economic-recreational
valuation of Own-ebne-Ali
Forest Park in Tabriz
Abbas Esmaeeli1
Negin Latifi Oskoei2(Corresponding author)
1-Faculty of Natural Resources and Marine Sciences, Tarbiat Modarres University
2-Faculty of Environment and Energy, Science and Research Branch, Islamic Azad Yniversity
Abstract
Own-ebne-Ali
Forest Park which is located in the north of Tabriz provides a variety of
important environmental services for the benefit of present and future
generations. These services have economic values that are often hard to
quantify in terms of general criteria because they do not produce any revenue
directly. However, they provide benefits in terms of the quality of life and
recreational opportunities and their economic value can be estimated mainly via
some indicators.
In this study,
Clawson method was used for the estimation of the social and economic values of
Own-ebne-Ali Park. This method was based on using the maps, preferences and
social and economic characteristics of the visitors and the relationship
between the cost of access to the park and the number of visitors. Then, the
demand curve was drawn based on the data obtained by questionnaires.
Calculations suggested the daily recreational-economic value of the park to be
125081000 Rials.
The results of
the study also indicated that most visitors of Own-ebne-Ali Forest Park were in
the age range of 20-30 years. Some 40% of the visitors had a diploma, as their
minimum educational degree, and 31.9% of them had a monthly income of 1-2
million Rials.
Key words: Forest park,
social and economic valuation, demand curve, environmental services, recreation, entrance fee,
Tabriz.
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
An Investigation of
phenol of Removal from contaminated water by almond and walnut
shells charcoal and activated carbon
Mohsen Saeedi1
Seyed Pejvak Pajooheshfar1(Corresponding author)
1-School of Civil Engineering, Iran University of Science and Technology, Tehran, Iran
Abstract
Adsorption
is one of the most effective processes in the final treatment of water for the removal
of organic matters and heavy metals. In the present study, the use of three carbonaceous
materials, i. e., Granular Activated Carbon (GAC), Almond Shell Charcoal (ASC)
and Walnut Shell Charcoal (WSC), were investigated as adsorbents for the removal
of phenol from contaminated water. Batch experiments were carried out to obtain
the best adsorption conditions. The correlation coefficients in Freundlich and
Langmuir isotherms turned out to be .99 and .99 for GAC, .92 and .96 for ASC,
and .93 and .95 for WSC. Maximum removal of phenol from contaminated water by GAC,
ASC, and WSC was 99.87%, 91.36%, and 78.17%, respectively.
Key words: Adsorption, activated carbon, almond shell, walnut shell, phenol
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
A qualitative and quantitative study of wastes in private hospitals of Tehran
Masoud Monavari1
Ghasemali Omrani1
Fatemeh Rezaei1(Corresponding author)
1-Faculty of Environment and Energy, Science and Research Branch, Islamic Azad University
Abstract
On average, 72,559 Kg of wastes is
collected daily from medical centers and hospitals in the city of Tehran. A thorough
qualitative and quantitative assessment of such wastes can help improve the current
hospital waste management practices.
In the present research, twenty
private hospitals in Tehran have been studied over a period of four months. The
data-collection instrument was a questionnaire comprising items concerning the number
of wards and occupied beds, and the amount of general and hazardous wastes of each
ward. The sample wastes taken from selected wards were weighed. The average
waste production rate turned out to be 8,430 kg per day. Given the 2,475 beds
in the hospitals under study, 3.406 kg of wastes per bed is generated daily. Surgery
and emergency wards generate the highest amounts of infectious waste per day --
2 and 1.8 kg per bed, respectively. The lowest amount is that of the children’s
ward with 0.25 kg per bed each day. Gynecology and children’s wards generate the
highest daily amounts of general waste (3 and 2.5 kg per bed, respectively). The
total amount of wastes generated was found to comprise 60% of general wastes,
39% infectious wastes and 1% of sharp wastes. Improper waste separation has led
to relatively higher amounts of infectious wastes. Encouragement and training
of hospital staff and improvement in collection and transportation processes by
Tehran Municipality are the key to successful hospital waste management.
Key words: Hospital waste management, infectious waste, general waste
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
The study of environmental problems and pollution management at the olefin plant of Bandar-e-Imam Petrochemical Complex
Sima Sabzalipour1(Corresponding author)
Nematallah Jaafarzadeh2
Houshang Parham3
1-Faculty of agriculture and environment, Islamic Azad University, Ahvaz
2-Environmental Health Jondi-Shapour University of Medical Sciences, Ahvaz
3-Chamran University, Ahvaz
Abstract
In this research, the olefin plant of Bandar-e-Imam Petrochemical Complex
was studied in terms of environmental problems. Waste water, air pollutants, noise
pollution and solid wastes were recognized as the sources of pollution. Then, the
sampling sites were chosen, the quality parameters were defined for the waste
water and air pollutants, and the samples were taken over a period of 6 months.
The results of the study show that the concentration of COD, OIL, TDS parameters
and of the phosphate ion in the waste water of the olefin plant were much
higher than the national standards.
The estimation of the pollution load for the mentioned parameters also
confirmed this finding. The amounts of atmospheric pollutants (CO, NOX
and SO2) in the studied plant were found to be within the range allowed by the Environmental
Protection Organization. Hydro carbonic vapors (HCVs) were among the other
pollutants at the plant. The study of noise pollutants showed that the highest
balance of noise pressure in the olefin plant was 102 dB (A). Moreover, 14
types of solid waste were identified, of which 10 (constituting 84% of the
total solid wastes) were found to be hazardous.
Key words: Petrochemical
complex, environment, pollutants, hazardous wastes, olefin plant
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
Green Management
System at the National Library of Itan
Kazem Naddafi1
Jafar Nouri1
Ramin Nabizade1
Nazak Shahbod2(Corresponding author)
1-School of Public Health and Institute of Health Researches, Tehran University of Medical Sciences
2-School of Environment and Energy, Science and Research Branch, Islamic Azad University
Abstract
Since the
establishment of Green Management System in various organizations is one of the
government’s priorities and due to the importance of Green Management for a
decrease in the consumption of resources such as water, energy, paper and waste
management, the implementation of this system in the National Library of Iran
is a necessary issue, which is studied in the present paper. First, the goals
were defined and the framework for the correct management of resources
consumption (Green Management) was specified. Then, the consumption of resources
at the National Library was studied so that managerial solutions could be
offered. To this end, the library was visited several times, certain checklists
and questionnaires were completed, and the necessary data were collected and
analyzed.
The obtained
results regarding the fuel energy consumed by transportation in the National
Library show that among the generated pollutants (CO2, CO, NOx and
hydrocarbons), CO2 has the highest rate (904 Kg). CO (6 Kg), NOx (2 Kg) and
hydrocarbons (0.58 Kg) are in the next ranks. Among energy-consuming equipment
and appliances, refrigerators produce the highest amount of CO2, SO2 and Nox.
The CO2 produced by all of them amounts to 1140.32 Kg; the figures for SO2 and
NOx are 3.9072 Kg and 2.886 Kg, respectively.
As to the
consumption of water, the results show that the total amount of water consumed
by the library is as much as 45459 L/Y, most of which (32471 L/Y) is used for
the irrigation of green space. Regarding wastes, 30 times of sampling revealed
that most of them were aluminum and paper wastes. The amounts of CO2, SO2, NOx
and particles were 19475 Kg, 77.54 Kg, 57.4 Kg, and 2.92 Kg, respectively.
Finally, it has
been made clear that the Green Management can help optimize the use of
resources and reduce the costs.
Key words: Green
Management System, pollutant, waste management, optimum consumption, consumption
management
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
Adaptive role of
Tehran on the development of the spatial structure of Lavasan and Sharifabad
cities from 1970 to date
Mostafa Momemi1
Mohamad Taghi Razavian1
Habibollah Mahdavivafa1
1-Faculty of Earth Sciences, Shahid Beheshti University
Abstract
This research
studies the factors affecting special organizational evolution of Lavasan and
Sharifabad cities from the 1970s up to the present time based on geographical
structuralism school, the political economic viewpoint of space, and the theory
of rantier economy and state. Studies have shown that the nature of
socio-economic system dominant in Tehran has deep and extensive effect on
production and special formation of this city and its neighboring villages and
cities. Moreover, the performance pattern of planning and management of civic
and regional development originates from this in dangerous and exogenous
socio-economic structure. This structure is one of the oil income versions that
has shown its effects on special development of Iran and metropolitan Tehran
and its periphery specially Lavasan and Sharifabad. The results and effects of
imbalance and domination of Tehran with its periphery special units from the
recent decades and unorganized, scattered, and without program trend of Tehran
civic development has caused the process of changing villages to cities to
continue and these units to encounter several socio-economic, population,
physical, and environmental problems. Among these factors, the habitats of the
peripheral region, under the effect of the role and performance of Tehran, have
faced with different structural and functional evolution developments, each of
which regarding its natural environmental, social, economic, and physical
conditions has caused a special spatial structure (as in Lavasan and
Sharifabad.
Key words: Political economy of space, special structure, Tehran metropolis, periphery region.
J.Env.Sci. Tech., Winter 2009, No.39 Special issue
Phenomenology of the urban environment: promoting urban spaces to urban places
Hadi Mahmoodi Nejhad1(Corresponding author)
Mohammad Reza Pour Jaafar1
Mohammad Reza Bemanian1
Mojtaba Ansari1
Ali Akbar Taghvaei1
1-Faculty of Art and Architecture, Tarbiat Modarres University
Abstract
The neutrality
of living spaces in the urban environment and man’s lack of space in the urban
structure both indicate that contemporary man is suffering from homelessness
and lack of space. That is why citizens
and urban dwellers have lost their identity and their interaction with the
environment.
The mission of urban
planning is to enhance urban spaces to places in which social and human values
can be manifested.
Phenomenology
has the potential to create meaningful environments and call for a sense of
place, spirit of place, and meaning of place, all of which being the basic
elements of the identity of a place. The
results of the present study have shown that it is not needed to look for a new
designing style; instead, it is necessary to search for traditional meanings
and values in the architecture and construction of cities with especial
attention to phenomenological approach.
Key words: Urban environment, holding of identity, place, urban spaces, phenomenology of the place