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Effluent from an advanced wastewater treatment plant — an alternate source of non-potable water for Kuwait
Desalination 196 (2006) 215–220
Effluent from an advanced wastewater treatment plant — an alternate source of non-potable water for Kuwait S.B. Al-Shammari*, A.M. Shahalam Water Technologies Department, Kuwait Institute for Scientific Research, PO Box 24885, Safat 13109, Kuwait Tel. +965 487-8122/4; Fax: +965 487-9238; email: [email protected] Received 10 May 2005; accepted 12 October 2005
Abstract During the past few years, Kuwait has been encouraging the development of alternative water resources. This stems from the fact that the available natural water resources are scarce, and water demands are growing due to increasing population growth. A potential alternative water resource which may replace existing water resources for non-potable use is renovated wastewater. Currently, a huge amount of municipal wastewater is conventionally treated in Kuwaiti sewage treatment plants, and a major portion of this treated effluent is discharged to the Gulf. Advanced treatment of treated wastewater would yield a better quality effluent which can be used as an alternative water resource and therefore reduces the demand on fresh and brackish water supplies. The potential for using advanced treated wastewater in meeting the growing water demands in the State of Kuwait was explored. Keywords: Water demand; Advanced treatment; Wastewater reuse
1. Introduction The development of sustainable water resources in Kuwait, which is an arid country with a fast-growing population, faces major challenges for future sources. Since the mid-1950s, Kuwait has put effort and money to secure safe and renewable water resources that can be used for domestic, industrial and commercial purposes. At present, most of the potable water supplies in Kuwait are produced by multistage flash (MSF) *Corresponding author.
desalination plants. Water requirements for agricultural and other uses are met by brackish groundwater. A portion of tertiary treated wastewater is used for fodder irrigation. However, there is increasing concern about the production cost of desalinated water and the depletion rate of ground water. In this context, effective and efficient reclamation and reuse of wastewater is considered as an important element of water resources development and management. It can provide a viable and sustained water supply for non-potable uses and reduce the need for cost-
0011-9164/06/$– See front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.desal.2005.10.040
216
S.B. Al-Shammari, A.M. Shahalam / Desalination 196 (2006) 215–220
intensive desalination plants. This potential water resource provides an innovative and alternative option for non-potable uses such as irrigation and landscaping. Other alternatives include water conservation, efficient management, and development of new water resources. The quantities of wastewater are huge: about 60–70% of the daily freshwater consumption rate [1]. The average domestic water consumption in the year 2001 for a population of 2.2 million was 415 million m3 [2]. Limitations on freshwater are likely to have a significant impact on economic and social development in Kuwait. In addition to the above concern, ecosystem deterioration caused by wastewater discharge to the Gulf water has become a major concern. This concern resulted from the effluent quality produced in conventional wastewater treatment plants in Kuwait. In these plants, the municipal wastewater effluent is usually treated to a tertiary level. However, many of the pollutants found in wastewater are not completely removed or are partially removed by conventional treatment processes. These constituents main consist of both organic and inorganic compounds. The impact of these substances on the environment and especially the aquatic ecosystem is adverse in nature. For example, the presence of phosphate and nitrate is often responsible of the depletion of dissolved oxygen in receiving water by stimulating algae and undesirable aquatic growth. Therefore, environmental legislation has become more stringent in terms of allowable concentration of such substances in the effluent of wastewater treatment plants.
2. Geographical and climatic conditions of Kuwait Kuwait is located in the northwest corner of the Arabian Gulf and is considered an extremely arid country. Kuwait, with a population of 2.2 million, has a total land area of 17,818 km2
Table 1 Overall quantities and percent share of Kuwait’s water supply resources for year 2001 [2,4] Water resources
Million m3/y
% share
Desalination Groundwater Reused wastewater
386 145 26
69.2 26.0 4.7
including the land areas of the offshore islands. The climate is very adverse and harsh, i.e., hot, dry, dusty, desert-like, with average temperatures of 0EC in the winter and 49EC in the summer. Rainfall is low and mainly occurs during four winter months, from November to February. Average annual rainfall is about 110 mm/y, whereas the mean annual evaporation rate is about 4000 mm [3]. 3. Water resources and demand in Kuwait Natural water resources in Kuwait are very limited and mainly consist of brackish groundwater. Non-conventional water resources include seawater desalination and reclaimed wastewater. Most of the fresh water supplies in Kuwait are produced through five MSF desalination plants [2]. These plants were developed and have been in use since the 1950s. Brackish water is produced from a groundwater aquifer and is blended with distilled water for irrigation and landscaping. Treated wastewater is used in very limited quantities in fodder (animal feed) production and landscaping activities. Table 1 outlines the overall quantities and percent share of Kuwait’s water supply resources for year 2001 [2,4]. Distilled and groundwater dominate and share more than 95% of the available resources whereas renovated wastewater accounts for less than 5%. 4. Water demand The demand on water is growing due to rapid
S.B. Al-Shammari, A.M. Shahalam / Desalination 196 (2006) 215–220
217
Fig. 1. Development of Kuwait’s population and rate of total water production in the past 10 years.
population growth, urbanization and socioeconomic development. Kuwait’s population has doubled in the past 30 years and is predicted to double in the next 30 years. Fig. 1 shows the development of Kuwait's population and rate of total water production in the past 10 years [2]. During 1977, the average consumption of freshwater per capita reached about 50 m3/y. This number increased over the next years and has continued to grow at a very high rate. In 2003 the per-capita consumption reached more than 180 m3. This large quantitative growth in consumption per capita cannot be sustained without corresponding growth in the distillation production capacity. Fig. 2 shows the growth rates and annual changes in production of desalinated water and the gross and per capita freshwater consumption over the past 25 years in Kuwait [5]. The increasing water demand, domestic and non-domestic (agricultural and industrial) are met basically by seawater distillation and groundwater supplies. Domestic demands dominate a share of about 77% of total water supplies available in Kuwait [6]. The sectoral withdrawals of water in Kuwait are shown in Table 2. Although Kuwait is arid and has very little agricultural activity, irrigated agriculture is the largest water user with a share of 60%. The domestic share of water is second in line and accounts for 37%. The industrial share of water is less than 2%.
Fig. 2. Growth rates and annual changes in the production of desalinated water and gross and per capita freshwater consumption over the past 25 years in Kuwait. Table 2 Sectoral withdrawals of water in Kuwait [6] Sector
Withdrawal percent, %
Domestic Industrial Agricultural
77 2 21
The trend of water consumption indicates that water demand is huge and will continue to grow in the future. Table 3 presents the population, projected 2025 population, sectoral and total water demands in Kuwait. The increasing water demand, particularly in non-domestic uses, can be met by promoting the use of treated wastewater, especially in the agricultural sector. This will reduce brackish groundwater withdrawal and save depleting aquifer reserves.
5. Wastewater in Kuwait The amount of wastewater produced varies with the season, and this amount is expected to increase as more residential areas are connected to the sewage system [7]. Presently, three sewage treatment plants at Ardiyah (294,000 m3/d),
218
S.B. Al-Shammari, A.M. Shahalam / Desalination 196 (2006) 215–220
Table 3 Population and projected population, sectoral and total water demand [8] Year
1990 2000 2025
Population (000)
2.2 2.4 3.6
Water demand (million m3) Domestic
Agriculture
Industrial
Total
295 375 670
80 110 140
8 105 160
383 590 970
Regga (102,000 m3/d) and Jahra (54,000 m3/d), are used to treat municipal wastewater [4]. The collected wastewater receives primary, secondary and tertiary treatment. At the primary level, physical separation processes such as screening, sedimentation and grit removal are used to remove large objects and settable solids. In the secondary treatment, biological processes are used in which microorganisms convert nonsettable and dissolved organic pollutants to settable solids. A sedimentation process typically follows, allowing these settable solids to be removed. In the tertiary treatment, the secondary effluent is usually disinfected using chlorine and then filtered to eliminate residual suspended solids. The total daily inflow into these treatment plants amounts to about 164 million m3/y, which is about 39% of the total annual potable water used in the country. Part of the tertiary effluent is diverted for irrigation, landscaping and gardening whereas a major portion of the treated effluent is discharged into the Gulf. Fig. 3 shows quantities of treatment plant influent and effluents, reused and discharged to the Gulf [4]. Given the limited available water resources and increasing demand, municipal wastewater can have a special role in maintaining and augmenting water resources in Kuwait since wastewater effluent is estimated to be 70–80% of the freshwater consumption per capita [9]. Therefore, reclaimed water can be considered as a primary option for developing new water resources
Fig. 3. Quantities of treated, reused and discharged water to the Gulf.
through water reuse in irrigation and landscaping. However, the extent of reusing this resource in agricultural activities is very limited because of health regulation and environmental concerns. Therefore, the potential of reusing conventionally treated wastewater effluent can be increased by reducing or eliminating hazardous substances. This can be accomplished by polishing the effluent with more advanced techniques. Membrane technology is a potential separation method that can be used as an advanced treatment for wastewater. Reverse osmosis (RO) and microfiltration (MF) are the most successful membrane separation processes adopted recently in the field of wastewater treatment [10,11]. Two studies were conducted recently in the Kuwait Institute for Scientific Research to evaluate the feasibility of RO and MF treatment of wastewater effluent from tertiary treatment plants [11,12]. The results indicated significant improvement of wastewater effluent quality for both MF and RO. For
S.B. Al-Shammari, A.M. Shahalam / Desalination 196 (2006) 215–220
example, a significant reduction in chemical oxygen demand and biological oxygen demand were noticed in the filtrate and permeate of MF and RO, respectively. Bacteriological and viral analyses of the advanced treatment product show that the water is free from microorganisms and other biological matter. Techno-economic analysis of these treatment methods proves that the MF and RO systems are feasible and reliable in production of an excellent quality of water free from impurities compared to conventional treatment methods. Based on these findings, the government of the State of Kuwait decided to construct a wastewater treatment and reclamation plant at Sulaibiya in the context of privatization. The main objective of the intended facilities is to produce an effluent of such quality to allow its beneficial “reuse” by consumers. The Sulaibiya Wastewater Treatment and Reclamation Project (WWT&RP) is intended to resolve two problems: The existing Ardiya WWTP is no longer able to treat the increasing amount of wastewater and cannot be extended at its location, and brackish water resources are no longer sufficient to cover the increasing non-potable water demand. To solve these two problems by means of one plant, the objective of the new Sulaibiya WWT&RP is to treat wastewater to such an extent that it could be used for unrestricted non-potable purposes. The capacity of the Sulaibiya WWT&RP (375,000 m3/d with an option to be extended to 600,000 m3/d) makes the project by far the largest of its type in the world. Approximately 85% of the inflowing wastewater will be reclaimed for reuse and 15% will be discharged to the sea as brine.
6. Potential wastewater reuse in meeting Kuwait’s water demand The State of Kuwait used nearly 415 million m3 [2] of water for domestic purposes in the year 2001. Assuming 70% of the water use turned
219
Table 4 Percentage distribution of treated wastewater use in Kuwait [13] Item
Total potential amount, %
Direct use for fodder production Plants, trees and landscaping Roadside landscaping, etc.
26.0 0.3 6.7
to be wastewater, the available wastewater is nearly 290 million m3/y. Present uses of tertiary effluent is nearly 95 million m3/year [13], which is about 33% of the potential available wastewater. The distribution of percentages for various uses appears in Table 4. Three planned agricultural farms presently use most of the irrigation water for fodder production. For this purpose, trunk-line and pump stations are used to convey the generated wastewater effluent to a central reservoir for distribution of the effluent to the point of use. Recently the State of Kuwait constructed a new centralized wastewater treatment plant with treatment facilities beyond the tertiary level. The advanced treatment includes filtration, RO refinement and carbon adsorption. The effluent of the plant is expected to be a quality that is appropriate for unrestricted irrigation. When this new facility is in operation, nearly 60–70% of total domestic water use will be recycled for reuse. The reuse will substantially reduce the freshwater need for irrigation. 7. Conclusions The State of Kuwait has undertaken a pioneering step towards total utilization of treated wastewater effluent in the country for beneficial use. The process included the construction of infrastructures such as the effluent collection system needed to convey water to centralized reservoirs, pump stations, trunk-lines, reservoir maintenance, water allocation, and distribution
220
S.B. Al-Shammari, A.M. Shahalam / Desalination 196 (2006) 215–220
systems to the point of use. Once completed by the year 2005, total treated domestic wastewater generated in the country will be utilized for irrigation and landscaping purposes. Other uses subsequently may also be justified if such an opportunity arises. The step undertaken is appropriate for a country like Kuwait with an extremely arid climate and immense water shortage.
References [1] M. Abdel-Jawad, S. Al-Shammari and F. Al-Atram, Municipal wastewater desalination by reverse osmosis, Final Report, KISR 5224 WW 001C, 1997. [2] Ministry of Electricity and Water, Kuwait, Statistical Year Book: Water, 2002. [3] Ministry of Planning, Kuwait, Statistial Year Book, 2002. [4] Ministry of Public Works, Kuwait, Process Yearly Reports, 2002. [5] Ministry of Electricity and Wter, Kuwait, Statistical Year Book: Water, 2003. [6] I.M. Abdel-Magid, Effective water policies and
[7]
[8]
[9]
[10]
[11]
[12]
[13]
planning for national water authorities. Arabian J. Sci. Eng., 22(1C): (1997) 199–212. E. Al-Awadi and T. Rashid, Change in treated wastewater quality through soil aquifer treatment, Final Report, KSIR 5725 WW002C, 1999. World Bank, Environmental Department, Water stresses and water scarce countries: 2025 projections, Strategy Series No. 2, 2001. N. Al-Awadi, K. Puskas and H. Malek, Option for treated wastewater reuse in post-war Kuwait. Proc. First Gulf Water Conf., 1992. S. Al-Shammari and M. Abdel-Jawad, Desalting of tertiary treated wastewater by reverse osmosis, Proc. Amer. Desalting Assoc., Desalting Revolution, VA, USA, 1998, p. 279. S. Bou-Hamad, S. Al-Shammari, S. Ebrahim and N. El-Touney, Treatment of tertiary treated wastewater by microfiltration, Final Report, KISR 5337 WD004K, 1998. M. Abdel-Jawad, S. Al-Shammari and J. Al-Sulaimi, Non-conventional treatment of treated municipal wasteater for reverse osmosis. Desalination, 142 (2002) 11–18. Data Monitoring Center, Ministry of Public Works, Kuwait, 2004, pers. comm.
Effluent from an advanced wastewater treatment plant — an alternate source of non-potable water for Kuwait S.B. Al-Shammari*, A.M. Shahalam Water Technologies Department, Kuwait Institute for Scientific Research, PO Box 24885, Safat 13109, Kuwait Tel. +965 487-8122/4; Fax: +965 487-9238; email: [email protected] Received 10 May 2005; accepted 12 October 2005
Abstract During the past few years, Kuwait has been encouraging the development of alternative water resources. This stems from the fact that the available natural water resources are scarce, and water demands are growing due to increasing population growth. A potential alternative water resource which may replace existing water resources for non-potable use is renovated wastewater. Currently, a huge amount of municipal wastewater is conventionally treated in Kuwaiti sewage treatment plants, and a major portion of this treated effluent is discharged to the Gulf. Advanced treatment of treated wastewater would yield a better quality effluent which can be used as an alternative water resource and therefore reduces the demand on fresh and brackish water supplies. The potential for using advanced treated wastewater in meeting the growing water demands in the State of Kuwait was explored. Keywords: Water demand; Advanced treatment; Wastewater reuse
1. Introduction The development of sustainable water resources in Kuwait, which is an arid country with a fast-growing population, faces major challenges for future sources. Since the mid-1950s, Kuwait has put effort and money to secure safe and renewable water resources that can be used for domestic, industrial and commercial purposes. At present, most of the potable water supplies in Kuwait are produced by multistage flash (MSF) *Corresponding author.
desalination plants. Water requirements for agricultural and other uses are met by brackish groundwater. A portion of tertiary treated wastewater is used for fodder irrigation. However, there is increasing concern about the production cost of desalinated water and the depletion rate of ground water. In this context, effective and efficient reclamation and reuse of wastewater is considered as an important element of water resources development and management. It can provide a viable and sustained water supply for non-potable uses and reduce the need for cost-
0011-9164/06/$– See front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.desal.2005.10.040
216
S.B. Al-Shammari, A.M. Shahalam / Desalination 196 (2006) 215–220
intensive desalination plants. This potential water resource provides an innovative and alternative option for non-potable uses such as irrigation and landscaping. Other alternatives include water conservation, efficient management, and development of new water resources. The quantities of wastewater are huge: about 60–70% of the daily freshwater consumption rate [1]. The average domestic water consumption in the year 2001 for a population of 2.2 million was 415 million m3 [2]. Limitations on freshwater are likely to have a significant impact on economic and social development in Kuwait. In addition to the above concern, ecosystem deterioration caused by wastewater discharge to the Gulf water has become a major concern. This concern resulted from the effluent quality produced in conventional wastewater treatment plants in Kuwait. In these plants, the municipal wastewater effluent is usually treated to a tertiary level. However, many of the pollutants found in wastewater are not completely removed or are partially removed by conventional treatment processes. These constituents main consist of both organic and inorganic compounds. The impact of these substances on the environment and especially the aquatic ecosystem is adverse in nature. For example, the presence of phosphate and nitrate is often responsible of the depletion of dissolved oxygen in receiving water by stimulating algae and undesirable aquatic growth. Therefore, environmental legislation has become more stringent in terms of allowable concentration of such substances in the effluent of wastewater treatment plants.
2. Geographical and climatic conditions of Kuwait Kuwait is located in the northwest corner of the Arabian Gulf and is considered an extremely arid country. Kuwait, with a population of 2.2 million, has a total land area of 17,818 km2
Table 1 Overall quantities and percent share of Kuwait’s water supply resources for year 2001 [2,4] Water resources
Million m3/y
% share
Desalination Groundwater Reused wastewater
386 145 26
69.2 26.0 4.7
including the land areas of the offshore islands. The climate is very adverse and harsh, i.e., hot, dry, dusty, desert-like, with average temperatures of 0EC in the winter and 49EC in the summer. Rainfall is low and mainly occurs during four winter months, from November to February. Average annual rainfall is about 110 mm/y, whereas the mean annual evaporation rate is about 4000 mm [3]. 3. Water resources and demand in Kuwait Natural water resources in Kuwait are very limited and mainly consist of brackish groundwater. Non-conventional water resources include seawater desalination and reclaimed wastewater. Most of the fresh water supplies in Kuwait are produced through five MSF desalination plants [2]. These plants were developed and have been in use since the 1950s. Brackish water is produced from a groundwater aquifer and is blended with distilled water for irrigation and landscaping. Treated wastewater is used in very limited quantities in fodder (animal feed) production and landscaping activities. Table 1 outlines the overall quantities and percent share of Kuwait’s water supply resources for year 2001 [2,4]. Distilled and groundwater dominate and share more than 95% of the available resources whereas renovated wastewater accounts for less than 5%. 4. Water demand The demand on water is growing due to rapid
S.B. Al-Shammari, A.M. Shahalam / Desalination 196 (2006) 215–220
217
Fig. 1. Development of Kuwait’s population and rate of total water production in the past 10 years.
population growth, urbanization and socioeconomic development. Kuwait’s population has doubled in the past 30 years and is predicted to double in the next 30 years. Fig. 1 shows the development of Kuwait's population and rate of total water production in the past 10 years [2]. During 1977, the average consumption of freshwater per capita reached about 50 m3/y. This number increased over the next years and has continued to grow at a very high rate. In 2003 the per-capita consumption reached more than 180 m3. This large quantitative growth in consumption per capita cannot be sustained without corresponding growth in the distillation production capacity. Fig. 2 shows the growth rates and annual changes in production of desalinated water and the gross and per capita freshwater consumption over the past 25 years in Kuwait [5]. The increasing water demand, domestic and non-domestic (agricultural and industrial) are met basically by seawater distillation and groundwater supplies. Domestic demands dominate a share of about 77% of total water supplies available in Kuwait [6]. The sectoral withdrawals of water in Kuwait are shown in Table 2. Although Kuwait is arid and has very little agricultural activity, irrigated agriculture is the largest water user with a share of 60%. The domestic share of water is second in line and accounts for 37%. The industrial share of water is less than 2%.
Fig. 2. Growth rates and annual changes in the production of desalinated water and gross and per capita freshwater consumption over the past 25 years in Kuwait. Table 2 Sectoral withdrawals of water in Kuwait [6] Sector
Withdrawal percent, %
Domestic Industrial Agricultural
77 2 21
The trend of water consumption indicates that water demand is huge and will continue to grow in the future. Table 3 presents the population, projected 2025 population, sectoral and total water demands in Kuwait. The increasing water demand, particularly in non-domestic uses, can be met by promoting the use of treated wastewater, especially in the agricultural sector. This will reduce brackish groundwater withdrawal and save depleting aquifer reserves.
5. Wastewater in Kuwait The amount of wastewater produced varies with the season, and this amount is expected to increase as more residential areas are connected to the sewage system [7]. Presently, three sewage treatment plants at Ardiyah (294,000 m3/d),
218
S.B. Al-Shammari, A.M. Shahalam / Desalination 196 (2006) 215–220
Table 3 Population and projected population, sectoral and total water demand [8] Year
1990 2000 2025
Population (000)
2.2 2.4 3.6
Water demand (million m3) Domestic
Agriculture
Industrial
Total
295 375 670
80 110 140
8 105 160
383 590 970
Regga (102,000 m3/d) and Jahra (54,000 m3/d), are used to treat municipal wastewater [4]. The collected wastewater receives primary, secondary and tertiary treatment. At the primary level, physical separation processes such as screening, sedimentation and grit removal are used to remove large objects and settable solids. In the secondary treatment, biological processes are used in which microorganisms convert nonsettable and dissolved organic pollutants to settable solids. A sedimentation process typically follows, allowing these settable solids to be removed. In the tertiary treatment, the secondary effluent is usually disinfected using chlorine and then filtered to eliminate residual suspended solids. The total daily inflow into these treatment plants amounts to about 164 million m3/y, which is about 39% of the total annual potable water used in the country. Part of the tertiary effluent is diverted for irrigation, landscaping and gardening whereas a major portion of the treated effluent is discharged into the Gulf. Fig. 3 shows quantities of treatment plant influent and effluents, reused and discharged to the Gulf [4]. Given the limited available water resources and increasing demand, municipal wastewater can have a special role in maintaining and augmenting water resources in Kuwait since wastewater effluent is estimated to be 70–80% of the freshwater consumption per capita [9]. Therefore, reclaimed water can be considered as a primary option for developing new water resources
Fig. 3. Quantities of treated, reused and discharged water to the Gulf.
through water reuse in irrigation and landscaping. However, the extent of reusing this resource in agricultural activities is very limited because of health regulation and environmental concerns. Therefore, the potential of reusing conventionally treated wastewater effluent can be increased by reducing or eliminating hazardous substances. This can be accomplished by polishing the effluent with more advanced techniques. Membrane technology is a potential separation method that can be used as an advanced treatment for wastewater. Reverse osmosis (RO) and microfiltration (MF) are the most successful membrane separation processes adopted recently in the field of wastewater treatment [10,11]. Two studies were conducted recently in the Kuwait Institute for Scientific Research to evaluate the feasibility of RO and MF treatment of wastewater effluent from tertiary treatment plants [11,12]. The results indicated significant improvement of wastewater effluent quality for both MF and RO. For
S.B. Al-Shammari, A.M. Shahalam / Desalination 196 (2006) 215–220
example, a significant reduction in chemical oxygen demand and biological oxygen demand were noticed in the filtrate and permeate of MF and RO, respectively. Bacteriological and viral analyses of the advanced treatment product show that the water is free from microorganisms and other biological matter. Techno-economic analysis of these treatment methods proves that the MF and RO systems are feasible and reliable in production of an excellent quality of water free from impurities compared to conventional treatment methods. Based on these findings, the government of the State of Kuwait decided to construct a wastewater treatment and reclamation plant at Sulaibiya in the context of privatization. The main objective of the intended facilities is to produce an effluent of such quality to allow its beneficial “reuse” by consumers. The Sulaibiya Wastewater Treatment and Reclamation Project (WWT&RP) is intended to resolve two problems: The existing Ardiya WWTP is no longer able to treat the increasing amount of wastewater and cannot be extended at its location, and brackish water resources are no longer sufficient to cover the increasing non-potable water demand. To solve these two problems by means of one plant, the objective of the new Sulaibiya WWT&RP is to treat wastewater to such an extent that it could be used for unrestricted non-potable purposes. The capacity of the Sulaibiya WWT&RP (375,000 m3/d with an option to be extended to 600,000 m3/d) makes the project by far the largest of its type in the world. Approximately 85% of the inflowing wastewater will be reclaimed for reuse and 15% will be discharged to the sea as brine.
6. Potential wastewater reuse in meeting Kuwait’s water demand The State of Kuwait used nearly 415 million m3 [2] of water for domestic purposes in the year 2001. Assuming 70% of the water use turned
219
Table 4 Percentage distribution of treated wastewater use in Kuwait [13] Item
Total potential amount, %
Direct use for fodder production Plants, trees and landscaping Roadside landscaping, etc.
26.0 0.3 6.7
to be wastewater, the available wastewater is nearly 290 million m3/y. Present uses of tertiary effluent is nearly 95 million m3/year [13], which is about 33% of the potential available wastewater. The distribution of percentages for various uses appears in Table 4. Three planned agricultural farms presently use most of the irrigation water for fodder production. For this purpose, trunk-line and pump stations are used to convey the generated wastewater effluent to a central reservoir for distribution of the effluent to the point of use. Recently the State of Kuwait constructed a new centralized wastewater treatment plant with treatment facilities beyond the tertiary level. The advanced treatment includes filtration, RO refinement and carbon adsorption. The effluent of the plant is expected to be a quality that is appropriate for unrestricted irrigation. When this new facility is in operation, nearly 60–70% of total domestic water use will be recycled for reuse. The reuse will substantially reduce the freshwater need for irrigation. 7. Conclusions The State of Kuwait has undertaken a pioneering step towards total utilization of treated wastewater effluent in the country for beneficial use. The process included the construction of infrastructures such as the effluent collection system needed to convey water to centralized reservoirs, pump stations, trunk-lines, reservoir maintenance, water allocation, and distribution
220
S.B. Al-Shammari, A.M. Shahalam / Desalination 196 (2006) 215–220
systems to the point of use. Once completed by the year 2005, total treated domestic wastewater generated in the country will be utilized for irrigation and landscaping purposes. Other uses subsequently may also be justified if such an opportunity arises. The step undertaken is appropriate for a country like Kuwait with an extremely arid climate and immense water shortage.
References [1] M. Abdel-Jawad, S. Al-Shammari and F. Al-Atram, Municipal wastewater desalination by reverse osmosis, Final Report, KISR 5224 WW 001C, 1997. [2] Ministry of Electricity and Water, Kuwait, Statistical Year Book: Water, 2002. [3] Ministry of Planning, Kuwait, Statistial Year Book, 2002. [4] Ministry of Public Works, Kuwait, Process Yearly Reports, 2002. [5] Ministry of Electricity and Wter, Kuwait, Statistical Year Book: Water, 2003. [6] I.M. Abdel-Magid, Effective water policies and
[7]
[8]
[9]
[10]
[11]
[12]
[13]
planning for national water authorities. Arabian J. Sci. Eng., 22(1C): (1997) 199–212. E. Al-Awadi and T. Rashid, Change in treated wastewater quality through soil aquifer treatment, Final Report, KSIR 5725 WW002C, 1999. World Bank, Environmental Department, Water stresses and water scarce countries: 2025 projections, Strategy Series No. 2, 2001. N. Al-Awadi, K. Puskas and H. Malek, Option for treated wastewater reuse in post-war Kuwait. Proc. First Gulf Water Conf., 1992. S. Al-Shammari and M. Abdel-Jawad, Desalting of tertiary treated wastewater by reverse osmosis, Proc. Amer. Desalting Assoc., Desalting Revolution, VA, USA, 1998, p. 279. S. Bou-Hamad, S. Al-Shammari, S. Ebrahim and N. El-Touney, Treatment of tertiary treated wastewater by microfiltration, Final Report, KISR 5337 WD004K, 1998. M. Abdel-Jawad, S. Al-Shammari and J. Al-Sulaimi, Non-conventional treatment of treated municipal wasteater for reverse osmosis. Desalination, 142 (2002) 11–18. Data Monitoring Center, Ministry of Public Works, Kuwait, 2004, pers. comm.