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Newsletter and Technical Publications
<International Source Book On Environmentally Sound Technologies
for Wastewater and Stormwater Management>

2.3 Treatment (Topic c)

In the West Asia region, a diverse range of technologies are used in various countries ranging from conventional wastewater treatment methods and wastewater stabilization ponds in large communities to small-scale treatment technologies in small communities. Table 2.3 shows the major operational municipal wastewater plants in West Asia countries. Most of these treatment plants are overloaded due to uncontrolled population growth coupled with the slow development of new treatment facilities. For the purpose of this book, available technologies that are used in the region are grouped under two categories; (i) large scale technologies and (ii) community scale technologies.

2.3.1 Large scale technologies

Generally speaking most of the countries in the region do not have specific national standards for wastewater treatment technologies. The following conventional methods are used:

  1. Activated sludge plants
  2. Trickling filters
  3. Aerated lagoons
  4. Oxidization ponds or wastewater stabilization ponds

In Egypt, the number of treatment plants are increasing; from 22 treatment plants in 1992 treating about 650 million cubic meter per year to a potential of 123 plants treating about 4.9 billion cubic meters per year in 2005. Two major treatment plants (one is oxidation pond and the other is activated sludge) are completed for Cairo West and Cairo East. They are operating at very good efficiencies. Alexandria, being the second largest city, has a new activated sludge treatment plant with a capacity of 1.3 million cubic meters per day. Most of major cities will have wastewater treatment plants with priority given to coastal and tourist cities like Matrouh, Luxur and the new town in the Red Sea. Other cities in the new developed land (Sina and New Valley) do not have treatment facilities since they rely on septic tanks. The treatment plants of the industrial cities (10th of Ramadhan and 6th of October) are oxidation ponds designed to meet domestic wastewater plus the effluent of the industrial plant (of acceptable standards). In Egypt, although the use of waste stabilization ponds is increasing, activated sludge method is still the most common method.

In Jordan, there are 14 treatment plants in operation now; most of them are overloaded. The largest one is serving Greater Amman and Zarqa district with a population of 1.5 million inhabitants. As-Samra waste stabilization ponds (WSP) were designed for a capacity of 68,000 m3/day. Currently As-Samra WSP receives influent and organic loading far in excess (2.5 times) of the designed capacity. The plant consists of three trains; each has two anaerobic ponds, four facultative ponds and four maturation ponds. In spite of the excessive loading with respect to the design parameters, the removal efficiency of BOD and TSS at the facilities have declined only slightly. This situation is attributed to the fact that facultative (and probably maturation ponds) are acting anaerobicly, producing offensive odors and impacting several kilometers of the area around the facility. As-samra effluent BOD, COD, and TSS do not meet the Jordanian standard for the discharge of effluent to wadis. The government has completed a study (Herza 1997) for the rehabilitation, expansion and development of existing wastewater system in Amman- Zarqa basin area to treat about 600 m3/d by the year 2020. For the rest of the country, Table 2.4 illustrates some information on the different operating wastewater treatment plants. By comparing the design inflow to the actual inflow it is clear that 7 out 14 plants are operating under hydraulic and organic overloading.

In Kuwait, about 80% of the population are currently connected to the public sanitary sewage system, which delivers wastewater to four treatment plants. The largest is an activated sludge treatment plant with a capacity of 250,000 m3/ day serving Kuwait city. There are two other activated sludge plants treating 160,000 m3/ day and one aerated lagoon of 10,000 m3/ day capacity. All treatment plants have tertiary treatment facilities with rapid sand filtration producing water of good quality for irrigation.

In Lebanon, about 165 million cubic meter (MCM) of wastewater are produced annually; only 8 MCM are treated as of 1994. During the reconstruction period following the 15 year civil war, the government has completed a preliminary treatment plant in Beirut with a design capacity of 170,000 m3/day. Beirut treatment facilities employ screening, grit removal and settling. However, the infrastructure in sewer pipeline system has not been completed to connect all the city households to the treatment plant.

In Saudi Arabia, all major cities have wastewater treatment facilities with more than 40 treatment plants. Most of them are under loaded and comply with the effluent quality design criteria. For coastal cities like Al Khobar, Jeddah, and Damam, the secondary clarrifiers effluent is chlorinated before being discharged to the Gulf or the Red Sea. Inland cities like Riyadh have treatment plants, which are mainly activated sludge based with a few that use trickling filters and aerated lagoons. Tertiary treatment consists of rapid sand filters, lime softening, polishing ponds followed by chlorination or ozonation as disinfection. In Mecca, reverse osmosis is used as tertiary treatment before water is allowed to be used for irrigation and other reuses.

Table 2.3: Characteristics of major operational planned municipal sewage treatment plants in WA countries
Country Number of WWTP Design capacity in 1000 m3 /day Type of treatment Remarks
Bahrain 1 + 9 small scale 125 AS+DF+ O3 OL
Egypt 22 650 CT+AS+OP+PP+DF+O3  * 4 UC
Jordan 14 111.4 OP+AS+TF+PP+AL *1 OL
* 4 O
*2 UC
*2 UE
Kuwait 4 412 AS+AL+RSF *4 O
Lebanon 3 170 PT *2 UC
*1Disabled
Oman 10 385 AS+RSF * O
Qatar 8 100 AS+RSF * O
Saudi Arabia 5 620 AS+TR+AL+RO+LS+F+PP * O
Syria 7 1182 AS+AL+OP * O
UAE 3 410 AS+TF+RSF+O3 * O
Yemen 13 15 OP+CT -
W. B. NA NA NA * OL
AL: aerated lagoon O: operation RSF: rapid sand filter
AS: activated sludge O3: Ozonation TR: trickling filter
CT: conventional treatment OL: overloaded UC: under construction
F: filtration PP: polishing pond UE: under expansion
LS: lime softening PT: preliminary treatment  
OP: oxidation ponds RO: reverse osmosis  

In Oman, Qatar, and UAE, there are 21 treatment plants (Table 2.3), 24 of them use the activated sludge method and one only of trickling filter type. In all three countries about one million cubic meters per day is treated with rapid sand filters to produce good quality effluent. One plant in Abu Dhabi uses ozonation for disinfection.

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