Comparisons according to the treatment efficiency

Similar to the case of influent, the effluent from treatment plants in Jordan contains higher concentrations of pollutants (organic and nutrients) compared with that treated in Germany's plants as shown in Table 36.1. High effluent of organic material can reduce or deplete oxygen in water bodies, resulting in fish kills, odors, and overall degradation of water quality. Nutrients (N, P) can cause eutro-phication phenomenon in water bodies, which results in undesirable offensive conditions.

The average removal efficiencies of BOD, COD, NH4 , TP for Germany's plants were 98.6% , 95%, 94%, and 91%, respectively, in comparison with 92.8%, 87.9% , 55.8%, and 23% for Jordan's plants as shown in Fig. 36.1. The treatment plants in Germany also have high removal efficiency of TN (88%), while this parameter is not considered in the case of Jordan's treatment plants. The higher removal efficiency of treatment plants in Germany was attributed to many factors: applying of modern treatment technologies, high-qualified operators, strict regulations and the moderate strength of influent wastewater. On the other hand, Jordan still depends on natural stabilization ponds, which treats around 80% of its waste-water. The lack of expertise and limited financial support also contribute to the low treatment efficiency. Regarding BOD, COD, and TSS, 70% of the present plants have good removal efficiencies and comply with Jordanian standards for water discharged to the streams. Based on flow parameters, only 25% of the influent flow was treated with efficiency level >80% as shown in Figs. 36.2 and 36.3. Results also indicated that the organic load generated by 79% of the population equivalent was not reduced to the allowable standards. In Germany, 99%, 98%, 99%, 98%, and 99% of the treatment plants achieved the standard effluent limits in terms of BOD, COD, NH4, TN, and TP, respectively, as illustrated in Table 36.2.

BOD COD NH4 TP

Fig. 36.1 Removal efficiencies based on the average (by numbers) of all plants. 36.3.3 Comparisons according to the used technologies

There are 23 plants for municipal wastewater treatment in Jordan, 5 of which are stabilization ponds, 16 are mechanical mode, and 2 are used to treat the septic waste. Table 36.3 illustrates the applied technologies used to treat wastewater in Jordan. It is clear that about 80% of wastewater is treated naturally by stabilization ponds, which depends on the activity of bacteria, algae, and other plants found in ponds. The activities of these consumers increase as temperature and sunshine period increase, so the treatment is climate dependent, which explains the low efficiency obtained by these plants especially during winter season. All stabilization ponds in Jordan are overloaded based on both hydraulic and organic load, which is

BOD COD NH4 TP

Fig. 36.1 Removal efficiencies based on the average (by numbers) of all plants. 36.3.3 Comparisons according to the used technologies

There are 23 plants for municipal wastewater treatment in Jordan, 5 of which are stabilization ponds, 16 are mechanical mode, and 2 are used to treat the septic waste. Table 36.3 illustrates the applied technologies used to treat wastewater in Jordan. It is clear that about 80% of wastewater is treated naturally by stabilization ponds, which depends on the activity of bacteria, algae, and other plants found in ponds. The activities of these consumers increase as temperature and sunshine period increase, so the treatment is climate dependent, which explains the low efficiency obtained by these plants especially during winter season. All stabilization ponds in Jordan are overloaded based on both hydraulic and organic load, which is considered as an additional reason for low efficiency (Ammary, 2007). Most of the treatment plants do not have any technique to eliminate nitrogen, the reason of high concentration of ammonium in the effluent of these plants. Mechanical treatment plants (activated sludge and trickling filter) have higher removal efficiencies in comparison with waste stabilization ponds. It is important to mention that all of the waste stabilization ponds in Jordan will be converted to mechanical mode (Ammary, 2007). The recent trend of using modern mechanical treatment plants needs cooperation with well-qualified partners.

<70 70<E<80 80<E<90 90<E<95 95<E<100

BOD removal efficiency(%) Fig. 36.2 BOD removal efficiency based on the applied hydraulic load.

100 i

90-

80-

■O

o

70-

o

60-

"5

(0

50-

■a

> .C

40-

O

30-

20-

10-

0-

<70 70<E<80 80<E<90 90<E<95 95<E<100 COD removal effeciency(%)

Fig. 36.3 COD removal efficiency based on the applied hydraulic load.

Table 36.2 Efficiency of treatment plants in Germany.

Plant category

Num

Number

Number

Number

Number

Number

Viola

ber of

of

of

of

of

of

tion

(Population

plants

plants

plants

plants

plants

plants

%

equivalent)

violat

violat

violat

violat

violat

ing

ing

ing

ing

ing

BOD

COD

nh4

TN

P stan-

stan

stan-

stan-

stan-

dards

dards

dards

dards

dards

< 1000

89

1

2

_

_

_

3.3

>1,000 and

0

0

0

<5,000

79

>5,000 and

0

0

2

3.7

<10,000

53

>10,000 and

146

1

2

1

4

4

8.2

<100,000

>100,000

22

0

1

0

4

0

22.7

Sum

389

2

5

3

8

4

Violation %

0.5

1.3

0.8

2.1

1.0

Compliance %

99.5

98.7

99.2

97.9

99

Table 36.4 shows that 56% of the treatment plants in Germany are activated sludge mode, 13% are stabilization ponds, 4% use sequencing batch reactor methods (SBR), 2% are trickling filter, and 25% are operated either by multiple methods or by other techniques such as wetland and membranes. When Germany's authorities decide to construct a new treatment plant, the preferred technology is selected based on the desirable efficiency. In case high quality is required, or in case of sensitive water bodies, modern technologies are used such as membrane or multi-treatment stages.

Table 36.3 Methods of wastewater treatment in Jordan.

Type of

Number of

Hydraulic

Organic

Removal efficiency (%)

treatment*

plants

load %

loads %

BOD

COD

WSP

5

79.7

78.8

83

76.6

AS

9

11.7

11

97.1

93

AS+TF

3

6.6

7.8

95.2

91.8

TF

2

1.1

1.7

95

90.2

AP

1

0.9

0.6

94

88.6

Sum

20

100

100

* WSP: waste stabilization ponds, AS: activated sludge, TF: trickling filter, AP: aerated ponds, ASS: activated sludge simultaneous with sludge stabilization.

* WSP: waste stabilization ponds, AS: activated sludge, TF: trickling filter, AP: aerated ponds, ASS: activated sludge simultaneous with sludge stabilization.

Table 36.4 Methods of wastewater treatment in Germany.

Type of treatment

Number of plants

Hydraulic load %

Organic loads

%

Removal efficiency (%)

BOD

COD

WSP

53

0.7

0.8

96

91

AS

218

77.5

77

99

95

ASS

79

16.7

15.9

97

96

TF

7

0.10

0.1

94

87

SBR

15

0.8

0.8

99

96

AS+TF

2

2.9

3.2

98

96

Others

15

1.3

1.4

98

94

Sum

389

100

100

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