Wastewater Reuse in Irrigation through Applying IWRM Concept...IWW OWW BWW GWL2 GWL3 Water resources pH . Studied traits df Significance level IWW OWW BWW GWL 1 GWL 2 GWL 3 Lsd 0.05

Wastewater Reuse in Irrigation

through Applying IWRM Concept “Effluent of Sana'a Treatment Plant

a case study” Al-Eryani A. A.; Al-Nozaily F.A.; and Al-Muselehi

S.W.H.

Email:

mailto:[email protected]

Introduction: Growing population and climate change are heightening water shortage

Globally there is an awareness raising to dispose wastewater safely

and beneficially.

Using treated wastewater in agriculture should be taken into

consideration to achieve the flowing advantages :

water saving through reduction of fresh water demand,

increasing food production through increasing irrigation water supply

increasing crops nutrients availability ,

and improving environment quality through enhancing wastewater

treatment plant and phytoremediation.

In arid and semi-arid countries like Yemen there is huge amount of

wastewater produced by big cities , and there is lack of fresh water

supply for human daily needs and for agricultural production , so

wastewater reuse for irrigation becomes necessary as alternative new

resource to solve this problem.

Research Problem Activated sludge - Extended aeration Sana’a wastewater

treatment system is considered as a flexible and powerful technology

But this treatment system is overloaded due to increasing of Sana’a city effluents, with no system updating

Also the application of design parameters is ignored due to :

pressure of drought effects experienced in Yemen

and increasing agriculture activities in the studied area

This overloading has resulted into declining of SWWTP efficiency, with the habit of using bypass wastewater in irrigation

So health and agronomic risks of using wastewater are expected to appear in the studied area.

Study Objectives: The main objective of the study is to study the

suitability of Sana’a treatment plant effluents reuse in irrigation through the following evaluations :

• Health impacts of SWTP effluent on people (farmers and crop consumers) in Bait Handhal area.

• Impacts of the effluents on soil productivity (salinity, sodicity, macro nutrients and trace elements concentrations).

• Socio-economic impacts of using wastewater in agriculture in the studied area through IWRM aspect s.

Methodology The methodology of this study consist of the following:

Wastewater sampling and analysis

To study the chemical and biological characteristics of wastewater, 18

wastewater and ground water samples were taken from 6 different resources

of Sana'a wastewater treatment plant effluent channel and ground water.

These resources are: inlet wastewater (IWW), outlet treated wastewater (OWW),

mixed of bypass untreated wastewater and treated wastewater (BWW),

groundwater from location1 (GWL1), groundwater from location2 (GWL2),

groundwater from location3 (GWL3 )

Soil sampling and analysis Two types of soil were selected, the first soil is irrigated with wastewater in Bait Handhal and the second soil in Bait Al-Jahillia which irrigated with groundwater 6 samples from each type of soil were taken and tested for physical and chemical analysis like EC, pH, K, Fe, OM, , SAR, P and soil texture.

Crop sampling

36 samples of 4 crops (sorghum, barley, alfalfa and cabbage) were taken to study

the health impacts (fecal coliform and total coliform) of crops irrigated with

wastewater in comparing with those irrigated with ground water,

and 12 samples of alfalfa and cabbage were taken to study the effects of irrigation

period (2and 10 days ) On TC and fecal coliform

the study area

Socioeconomic study by using 45 farmer Questionnaires (25

for men and 20 for women) were implemented in the studied

area for many details in this field

Statistical analysis

SPSS program is used (T-Test) to compare between the

following :

soil irrigated with wastewater and soil irrigated with groundwater

crops irrigated with wastewater and with groundwater

and using ANOVA procedure for comparing water resources

.

SWTP = Sana'a Wastewater Treatment Plant

= Wastewater samples

= Soil samples

= Crops samples

Figure 3.1 the locations of wastewater

(ww) samples in Bait Handhal

Figure 3.2 the locations of soils

samples in Bait Handhal


samples in Bait Al-Jahli

Figure 3.4 the locations of crops

samples in Bait Handhal


samples in Bait Al-Jahelia

Studied

traits

df Significanc

e level

IWW OWW BWW GWL1 GWL2 GWL3 Lsd0.05

EC (µs/cm) 5 ** 2293 2067 2210 2130 2150 2253 67.3

TDS ( mg/l) 5 ** 1491 1343 1437 1393 1398 1465 46.1

pH 5 ** 7.3 7.5 8.3 8.2 6.8 7.8 0.26

Table and Fig. ( 1.1) Analysis of variance for studied traits differences

among water resources samples and their means

Result and Discussion

0

500

1000

1500

2000

2500

3000

3500

4000

4500

IWW OWW BWW GWL1 GWL2 GWL3

Water Resources

TDS

EC

6

6.5

7

7.5

8

8.5

9


Water resources

pH

Studied

traits

df Significance

level


NH3 ( mg/l) 5 ** 147 133 159 117 100 94 21.19

NO3 ( mg/l) 5 ** 6 8 10 13 16 13 2.42

SO4 ( mg/l) 5 ** 169 66 85.67 96 102.8 86.17 27.26

Table and Fig.(1.2) Analysis of variance for studied traits differences among

water resources samples and their means

0

50

100

150

200

IWW OWW GWL1 GWL2 GWL3

Water Resources

NH3

NO3

SO4

Studied

traits

df Signific

ance

level


Ca ( mg/l) 5 ** 80 74 83.33 112.67 125 100.33 14.11

Mg ( mg/l) 5 * 30 27 39.33 36 37.33 39.67 5.05

K ( mg/l) 5 ** 46 42.67 35 28.67 36 35.33 3.79

Na ( mg/l) 5 ** 230 250.67 241 206.67 218.33 238.33 8.90

Table and Fig. (1.3) Analysis of variance for studied traits differences among water resources samples and their

means

0

50

100

150

200

250

300


Water resources

Ca

Mg

Na

K

Studied

traits

df Significanc

e level

IW

W

OWW BWW GWL1 GWL2 GWL3 Lsd0.05

SS ( mg/l) 5 ** 817.0 78.67 100.00 82.67 70.00 145.00 54.97

Table and Fig. ( 1.4) Analysis of variance for studied traits differences among water

resources samples and their means

0

200

400

600

800

1000


Water Resources

SS

Studied

traits

df Significanc

e level


BOD5 (

mg/l)

5 ** 1427 102.67 89.33 88.33 128 97.33 289.46

COD (

mg/l)

5 ** 2458 220 260 233.33 236.67 247.00 258.27

Table and Fig. ( 1.5) Analysis of variance for studied traits differences among water


-1000

0

1000

2000

3000


Watrer Resources

BOD5

COD

Studied

traits df

Significance

level IWW OWW BWW GWL1 GWL2 GWL3 Lsd0.05

Fecal

Coliform

(Col/100m)

5 ** 63666666

7 82000 146666 89333 47700 11366 3.8*108

Table and Fig. (1. 6)Analysis of variance for studied traits differences among water


0

200000000

400000000

600000000

800000000

IWWOWW

BWW GWL1 GWL2 GWL3

WaterResources

Fecal Coliform

Studied

traits

df Signifi

cance

level


Mn (ppm) 5 ns 0.08 0.006 00.40 000.1 0.002 0.0013 ns

Cu (ppm) 5 ** 0.004 0.0063 0.0018 0.0008 0.0008 0.000 0.001

Ni (ppm) 5 ** 0.267 0.35 0.17 0.08 0.107 0.063 0.121

Table and Fig. (1. 7)Analysis of variance for studied traits differences among water


-0.05

0

0.05

0.1

0.15

IWW

OW

W

BW

W

GW

L1

GW

L2

GW

L3

Water Resources

Mn

-0.002

0

0.002

0.004

0.006

0.008IW

W

OW

W

BW

W

GW

L1

GW

L2

GW

L3

Water Resources

Cu

0

0.1

0.2

0.3

0.4

0.5

IWW

OW

W

BW

W

GW

L1

GW

L2

GW

L3

Water Resources

Ni

Studied

traits

df Signifi

cance

level


Zn (ppm) 5 ** 0.0047 0.047 0.004

2

0.0023 0.0016 0.0000 0.01

Cd (ppm) 5 ns 0.0022 0.0018 0.001

2

0.0006 0.0022 0.002 ns

Pb (ppm) 5 ns 0.055 0.0032 0.002

5

0.0018 0.0021 0.001 ns

Table and Fig. (1.8) Analysis of variance for studied traits differences among water


-0.02

-0.01

0

0.01

0.02

0.03

0.04

0.05

0.06


Water Resources

Zn

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

Water Resources

Cd

-0.02

-0.01

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

Water Resourcrs

Pb

Studied Traits df Significance

level WWIS Mean

GWIS Mean

PH 10 ** 7.8683 8.1917

EC (µs/cm) 10 ** 841.833 563.333

TDS (mg/l ) 10 ** 547.166 366.000

0

200

400

600

800

1000

1200

WWIS GWIS

EC(µs/cm)

TDS(mg/l )

7.2

7.4

7.6

7.8

8

8.2

8.4

8.6

WWIS GWIS

PH

Table and Fig. (2.1) Group T- Test analysis for the studied traits differences among wastewater irrigated

crop (WWIC) and groundwater irrigated crop(GWIC) and their means

Soil Samples

Table and Fig. (2.2) Group T- Test analysis for the studied traits differences among wastewater

irrigated crop (WWIC) and groundwater irrigated crop(GWIC) and their means


level WWIS Mean

GWIS Mean

Total N (mg/l) 10 ** 31.166 14.250

P (mg/l) 10 ** 25.233 3.516

K ( mg/l) 10 ** 414.166 96.626

Ca (meq/l) 10 ** 3.506 2.693

Mg ( meq/l) 10 ** 1.176 1.073

-10

0

10

20

30

40

50

N P Ca Mg

WWIS

GWIS

-100

0

100

200

300

400

500

600

700

WWISGWIS

K (mg/l)


level WWIS Mean

GWIS

Mean

Na ( mg/l) 10 ** 402.500 427.833

SAR (meq/l) 10 ** 11.631 13.935

OM (mg/l) 10 ** 1.221 0.595

Table and Fig. (2.3) Group T- Test analysis for the studied traits

differences among wastewater irrigated crop (WWIC) and groundwater

irrigated crop(GWIC) and their means

385

390

395

400

405

410

415

420

425

430

WWIS GWIS

Water Resources

Na

10

10.5

11

11.5

12

12.5

13

13.5

14

14.5

WWIS GWIS

Water Resources

SAR

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

WWIS GWIS

Water Resources

OM




level WWIS Mean

GWIS Mean

Fe (mg/l) 10 ** 10.908 2.960

Cu ( ppm) 10 ** 0.9300 0.2200

Zn (ppm) 10 ** 0.9500 0.4583

Co ( ppm ) 10 ** 0.1950 0.0650

Ni ( ppm) 10 ns 0.2267 0.0967

Mn (ppm) 10 * 3.7000 2.2500

Cd ( ppm) 10 ** 0.0342 0.4042

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Cu Zn Co Ni

WWIS

GWIS

0

2

4

6

8

10

12

14

16

Fe Mn-0.2

0

0.2

0.4

0.6

0.8

WWIS GWIS

Cd

Studied Traits df Significance level Crop WWIC GWIC

Fecal Coliform 4 ** Cabbage 47.333 4.000

4 ** Alfalfal 13.667 2.667

4 ** Barley 20.333 9.000

4 ** Sorghum 13.667 2.667



0

10

20

30

40

50

60

Cabbage Alfalfa Barley Sorghum

Fecal Coliform

WWIC

GWIC

Crops Samples

Studied

Traits df Significance level Crop WWIC

mean GWIC

men Total

Coliform 4 ** Cabbage 93.333 12.333

4 ** Alfalfal 380.000 18.667

4 ** Sorghum 24.333 8.667 4 ** Barley 36.667 15.667

Table and Fig. (3.2) Group T- Test analysis for the studied traits differences

among wastewater irrigated crop (WWIC) and groundwater irrigated crop(GWIC)

and their means

-100

0

100

200

300

400

500

Cabbage Alfalfa Sorghum Barley

Total Coliform

WWIC

GWIC


level Crop 2 days 10 days

Fecal Coliform 4 ** Cabbage 163.3333 47.3333

4 ** alfalfa 190.0000 40.6667

Total Coliform 4 ** Cabbage 320.0000 93.3333

4 ** alfalfa 380.0000 80.0000

0

50

100

150

200

250

Cabbage alfalfa

Fecal Coliform

2 days

10 days 0100200300400500

Total Coliform

2 days

10 days



Conclusions Due to by-pass practice and poor performances of Sana'a

wastewater treatment plant, most of the physical, chemical, and biological characteristics of treated wastewater used for irrigation in the studied area didn't meet the professional quality standards of Yemeni standards draft (by the EPC.)

Under irrigation with wastewater, vegetable crops consumers, farmers and handlers may face high risk pathogen infections.

The results of the questionnaire in the health aspect revealed that most farmers are :

severing from skin problems,

complain gathering of insects (mosquitoes) that could transfer diseases from one place to another.

Some of them suffering from intestinal problems ( like diarrhea ) and fever.

The animals had absolutely intestinal problems due to drinking from the open wastewater channel.

Slight to moderate agronomic problems are expected due to soil salinity (EC < 2000 µs/cm) and severe crop toxicity of sodium (SAR > 9 meq/l)

The high suspended solids and organic matter in the effluent of Sana'a wastewater treatment plant (SS=215 mg/l) and (BOD=322 mg/l & COD=609 mg/l)). Lead to clogging problems of the soil pores and reducing water percolation and aeration.

Comparing between soil irrigated with wastewater and that

irrigated with groundwater revealed that :

- Sodium toxicity and permeability problem are expected in both of soils (SAR >9 meq/l)

- But the presence of calcium with high concentration in wastewater may reduce permeability problem caused by excessive amount of sodium.

- Sodium concentration of groundwater irrigated soil ( 427.8 mg/l ) is higher than that irrigated with wastewater ( 402.5 mg/l) , despite the concentration of sodium in wells is less than in wastewater, that probably due to salt accumulation from frequent deficit irrigation ( there is no salt leashing due to water scarcity )

According to the result of executed questionnaire in the study area most respondent said :

i. There are no effective regulations, and the enforcement of these regulations is seem to be difficult under water shortage and lack of job opportunities.

ii. There is a good income from selling of vegetable and fodder crops which are irrigated with wastewater .

iii. The farmers didn't need to use fertilizer under irrigation with wastewater, but at the same time they have to buy potable water because ground water in the studied area is contaminated with wastewater .

Recommendations Sana'a wastewater treatment plant effluent should receive a degree of

treatment that meet Yemeni standards recommended quality (drafted by the EPC).

In the meantime all wastewater arrived Sana’a treatment plant should be treated through expanding it’s capacity , and by-pass Practices should be stopped.

Irrigation by wastewater should be stopped for uncooked eaten vegetables;.

The cultivation of sorghum, Barley, wheat and alfalfa should dried as hay for animal ,and the grain of these crop should stored and cooked for human to avoid pathogenic risks.

Irrigation interval has to be long as much as possible to reduce health hazards especially before cutting.

Conventional wastewater irrigation methods should be replace with those suitable to reduce the contact with wastewater contamination

More awareness programs, should be done by the concerned bodies in regard wastewater reuse issues.

•Thanks too much for listening

Documents

Wastewater Reuse in Irrigation through Applying IWRM Concept...IWW OWW BWW GWL2 GWL3 Water resources pH . Studied traits df Significance level IWW OWW BWW GWL 1 GWL 2 GWL 3 Lsd 0.05