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Indonesian Journal of Science and Technology 4 (1) (2019) 28-38

Indonesian Journal of Science and Technology
Journal homepage: http://ejournal.upi.edu/index.php/ijost/

The Effect of Education Level on Accepting The Reuse of
Treated Effluent in Irrigation
Husam Al-Najar, Basel EL Hamarneh
1

Faculty of Science, Disaster Management Master Program. The Islamic University of Gaza, P.O. Box 108 Gaza
Strip, Palestine.

Correspondence: E-mail: halnajar@iugaza.edu.ps

ABSTRACT

ARTICLE INFO

Gaza strip suffers from a serious shortage in water resources
due to the continuous increase in population, life changes,
political conditions, and drought caused by climate change.
Due to demands for water for domestic use, it resulted
accumulation of large quantities of wastewater in the
treatment plant in Rafah. Therefore, reuse of treated
wastewater is one of the most recently accepted approaches
to save groundwater or domestic use. The aim of this
research is to study the treated effluent quality from Rafah
Treatment Plant, in addition to the effect of education level
of the farmers on reusing treated wastewater for irrigation.
A questionnaire was distributed to farmers to investigate the
acceptance of using treated effluent for irrigation,
meanwhile the effluent parameters tested were BOD, COD,
TKN, NH4, NO3, and P, accounted for 110, 250, 108, 127, 0.23,
17.9 mg/L, respectively. The concentration of Cd, Pb, and Cu
must be <0.003, <0.001, and 19.9 µg/L, respectively. Most of
reuse parameters were higher than the recommended levels
for the effluent reuse based on the recommended
Palestinian Standards for irrigation. About 80% of farmers
accept using treated wastewater in irrigation since there is a
close relationship between the educational level of farmers
and the acceptance of using of treated wastewater in
irrigation, as long as it is safe and healthy.

Article History:

© 2019 Tim Pengembang Jurnal UPI

Submitted/Received 11 Oct 2018
First revised 20 Jan 2018
Accepted 01 Mar 2019
First available online 09 Mar 2019
Publication date 01 Apr 2019

____________________
Keywords:
Education level,
Irrigation,
Treated Effluent,
Gaza strip.

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1. INTRODUCTION
Mediterranean
regions
are
characterized by serious water imbalance.
The imbalance between water demands
versus supply is due mainly to the limited
resources and uneven distribution of
precipitation, high temperatures, and
expanding needs for water demand (Fatta et
al. 2005). According to the Population
Reference Bureau, seeing world's fastest
growing populations is in the Gaza Strip,
where the population growth rate is 4.5% per
year, and their demand for water is
increasing every time (Martin, 2015). In the
Gaza Strip, over 50% of freshwater
consumption is devoted to agricultural
activities. Over exploitation of the aquifer
diminished seriously the quantity and quality
of groundwater badly needed for human
consumption as well as for agriculture as one
of the main sources of income in the Gaza
Strip. The reuse of treated wastewater could
be an essential option to solve the water
deficit crisis in Gaza Strip (PWA, 2015).
Irrigation using treated wastewater is
considered as a priority in Rafah due to
various factors, including the depletion of
groundwater resources and actually, reuse
would increase the available freshwater
resources for domestic and industrial use, in
addition the rainfall in Rafah is 250 mm/year
in comparison to 450 mm/year in the north
of the Gaza Strip. Moreover, agriculture is the
main job for income for most of Rafah
residents since the residents of Rafah have
high unemployment records due to the lack
of water resources for agriculture.
Assuming that 80% of the water used for
domestic usage returns as wastewater, the
potential wastewater produced from Rafah
Governorate will be more than 16,000
m3/day of the year 2020. This situation will
increase along with the increase in
population and demand for water supply.
The wastewater that is generated in
Rafah is currently discharged into the sea; a
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small amount infiltrates into the soil and
contaminates the groundwater. The efficient
treatment and reuse of such considerable
quantity
of
wastewater
in
areas
characterized by water crisis becomes a
priority at a local and national level to meet
increasing agricultural water demand, which
was identified as one of the main objectives
of the Palestinian water sector. However, the
soil in west Rafah is characterized by its sandy
texture with high infiltration rate (Abu Jabal
et al. 2018), irrigation by partially treated
effluent could increase the input of
pollutants to the groundwater. In addition,
the farmers acceptance to use the treated
effluent in irrigation is doubtful. Therefore,
the aim of this research is to study the
potential of reusing the treated effluent from
Rafah wastewater treatment plant for
irrigation and the effect of farmer education
on acceptance of reuse.
2. MATERIALS AND METHODS
2.1. Quality Measurement
The samples were taken from outlet of
Rafah
wastewater
treatment
plant
(RWWTP), due to the importance of the
wastewater properties on agricultural
practices, it is necessary to determine its
characteristics before consumption. The
samples were collected before winter
seasons on Tuesday 10/10/2017.
2.2. Sample Collection Method
A composite sample device was used to
take samples from RWWTP effluent. This device
programmed to take 200 milliliters per hour
during a 24 hours of period which is considered
standard for most determinations.
The samples were collected from RWWTP
effluent in a clean 2-liter plastic bottle. After
mixed sample collected by sampler device and
put in ice box, samples for microbiological,
chemical, and heavy metal analysis were
collected in sterile bottles and then sent to the
laboratory of Islamic university. The waste

Husam Al-Najar &. Basel EL Hamarneh. The Effect of Education Level on Accepting...| 30

water was analyzed according to the American
Public Health Agency (APHA, 2005).

employed for economy and speed (Fellows and
Liu, 2008).

2.3. Tested Parameters

Several factors can influence the size of the
required sample for a study, including the
purpose of the study, population size, sample
sizes used in similar studies, the risk of selecting
a “bad” sample, and the allowable sampling
error and resource constraints (Malhotra and
Birks, 2007). A statistical calculation approach
has been used in this study to calculate the
required sample size. The following formula was
used to determine the sample size of unlimited
population (De Vaus, 2002).

The tests were performed by using the
following parameters: BOD5, COD, NH4, TKN,
NO3, P, Cl, TSS, FC, TDS, pH, EC, Cd, Pb, Cu, Na,
Ca and Mg.
2.4. Questionnaire Design
A questionnaire according to Saunders et
al. (2009) is a method of collecting data that
consists of a series of questions and other
prompts for the purpose of gathering
information from respondents. According to
Johnson and Duberley (2000), a questionnaire is
a structured technique for data collection that
includes a series of questions, written or verbal,
that a respondent answers.
The questionnaire focused on the target
group "People working on agriculture", their
ability to fill out questionnaires was so simple
that they had to stay away from difficult terms
and clarify several words with examples. The
researcher asks closed questions, answers are
chosen as examples (yes or no) or closed
multiple choice and open questions. Answers
that follow open questions require additional
information from the respondent.
2.5. Sample Size
Study sample is a subset of the population
selected to participate in a research study and
its size refers to the number of the elements to
be included in a study (Tayie, 2005; Zikmund et
al., 2009). The aim of determining an adequate
sample size is to estimate the population
prevalence with a good precision (Naing et al.,
2006). It is an extremely rare possibility to
conduct full population surveys. Therefore, a
sample can be chosen from the study
population that is commonly referred to as the
‘target population’ (Malhotra and Birks, 2007).
The principles of statistical sampling, which
guarantee a representative sample are

To calculate the sample size for this study,
a statistical calculation was used. The following
formula was used to determine the sample size
of unlimited population (Creative research
system, 2008).

SS =

Z 2  P  (1 − P)
C2

where
SS = Sample Size.
Z = Z Value (e.g. 1.96 for 95% confidence level of
α = 0.05).
P = Percentage picking a choice, expressed as
decimal, (0.50 used for sample size needed). Its
value taken as 50% or 0.5 as it would lead to a
larger sample size (Naing et al. 2006).
C = Often, an ‘acceptable’ margin of error used
by survey researchers falls between 4% and 8%
of the 95% confidence level (DataStar, 2008).
Since the population is not high, a maximum
error of estimation (0.08) is a reasonable choice.
On the basis of the mentioned reasons,
sample size for this study can be calculated as
follows:

SS =

1.962  0.5  (1 − 0.5)
= 150
0.082

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The above sample size formula is valid if the
calculated sample size is smaller than or equal
to 5% of the population size (n/N ≤0.05) If this
proportion is larger than 5% (n/N >0.05), we
need to use the formula with finite population
correction (Bartlet et al., 2001; Naing et al.,
2006) using the following formula:

New SS =

SS
SS − 1
1+
pop

where
New SS = Corrected sample size.
Pop = Population size.
The population was “3452” agricultural
holder (PCBC, 2016), and the ratio between the
obtained sample size and the population equals
to (150/3452) = 0.043, which is less than 0.05.
As a result, in this study, 150 questionnaires
need to be distributed to farmers in Rafah
governorate, but researchers, distributed 160
questionnaires, because some questionnaires
were defect.
2.6. Statistical Analysis
The data should be presented in a wellstructured and easy way (Biggam, 2015).
Kothari (2004) defined data analysis as "the
computation of certain measures along with
searching for patterns of relationship that exist
amongst the data-groups".
The overall goal of data analysis is to arrive
at a general understanding of the phenomenon
under study (Tayie, 2005). The computerized
programs EXCEL and SPSS were used as the data
analysis tool to help tabulate data and analysis.
3. RESULTS AND DISCUSSION
The main objective of this study is to
investigate the quality of RWWTP effluent,
and to evaluate the impact of using treated
wastewater on quality of resources and
efficiency of farming activities. To achieve
the objectives of the study, the national and
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international reuse guidelines were reviewed
and compared with the case in RWWTP.
3.1. Quality Measurement
The average daily flow quantities
received from RWWTP reach 12,000 m3/d,
existing RWWTP provide only partial
treatment of the wastewater concerning
organic matter, due to inadequate treatment
system performance, inadequate design and
limited electricity supply. The influent BOD,
COD, TSS, TKN, NO3, pH, and EC account for
600, 1300, 596, 182, 0.4 (mg/L), 8.1, and
4600 µs/cm.
A range of concentrations of treated
effluent wastewater were tested (Physical,
chemical, biological, and heavy metals) for
samples taken from RWWTP effluent. The
results shown in Table 1 were evaluated
according to the guidelines and standards of
local, regional and international references
(FAO, 1992; PWA, 2005) guidelines.
3.2. Physical Properties
3.2.1.Hydrogen Potential (pH Value)
Natural water usually has a pH value
between 6.5 and 8.4 (Pescod, 1992), but is
seldom a problem by itself. Normally, pH is a
routine measurement in irrigation water
quality assessment.
3.2.2. Salinity hazard
Salinity is the saltiness or amount of
dissolved salt in a water which is derived
from conductivity. The salinity of the effluent
could be measured by two parameters TDS
and EC. According to (EPA, 2003) EC values
are still in the usual range of salinity where
the critical value of applied water should not
increase 3000 μs/cm.
The current salinity of treated effluent
from RWWTP has a severe degree of
restriction on use. Recommended EC of 2500
μs/cm for treating wastewater is used for
irrigation. Then, excessive salinity may
damage some crops. Salt concentration
improves soil absorption, reduces plant

Husam Al-Najar &. Basel EL Hamarneh. The Effect of Education Level on Accepting...| 32

uptake of soil nutrients, and reduces soil
fertility (Mbarki et al., 2017).
3.3. Chemical Properties
3.3.1. Sodium (Na) Hazard
Sodic water is water with high
concentration of sodium, which is relative to
the concentration of calcium and
magnesium. Result of effluent RWWTP
showed that sodium Na+ level of the applied
water concentration of RWW (543 mg/L)
exceeded the maximum level assigned
according to the (FAO, 1992) guidelines

showed that the concentration of calcium
and magnesium are 460 and 900 mg/L, respectively (FAO, 1992).
According to PS-742-2003, type of TWW
is unsuitable for irrigation due to the high Na
content. The higher concentration of Na in
wastewater is due to household products for
laundry, kitchen, bath, and cleaning (Shomar
et al., 2005). Also, sodium concentration is
associated with chloride (Cl) concentration
which is originally high in the Gaza Strip
ground water due to seawater intrusion
(Shomar et al., 2010).

Table 1. Quality parameters of effluent wastewater from RWWTP compared with local and international standards
Parameter
BOD5
COD
NH4
TKN
NO3
P
Na+
Ca++
Mg++
Cl
SAR
TSS
FC
pH
EC
Cd
Pb
Cu

Unit
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(meq/L)
(mg/L)
(CFU/100 mL)
Value
(μs/cm)
ppm***
ppm***
ppm***

TWW effluent of RWWTP FAO 1992
110
20-30
250
50-60
126.8
40
107.7
NA
0.225
50
17.9
30
543
900
89
400
88
60
786
1000
9.73
0-15
137
50
620,000
<1000
8.2
6.5-8.4
4650
0-3000
<0.003
10
<0.001
93
19.9
43

PS 742/2003*
45-60
150-200
NA
50
50
30
460
400
60
500
9
50
<1000
6-9
2500
10
100
200

* PS-742-2003 for dry fodder irrigation. *** ppm = (mg/L) = 1000 ppb NA: cannot give a relevant.

3.3.2. Sodium Adsorption Ratio (SAR)
SAR was widely accepted by researchers
to evaluate the potential soil degradation
caused by relatively high sodium content in
the soil profile. Sodium hazard is also usually
expressed in terms of the sodium adsorption
ratio (SAR). SAR is calculated from the ratio
of sodium to calcium and magnesium by using the following equation:

SAR =

Na
Ca + Mg
2
= 9.73

where
Na = 543/23 = 23.61 meq/L
Ca = 89/20 = 4.45 meq/L
Mg = 88/12 = 7.33 meq/L.
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SAR is an important parameter for the
determination of the suitability of irrigation
water because it is responsible for the sodium hazard. High Sodium Adsorption Ratios
reduce the infiltration rate of water into the
soil. The value of SAR for TWW of RWWTP
was 9.73 meq/l, slightly exceed the maximum allowable value 9 meq/l, acceptable according to FAO (1992) guidelines standards.
Sodium content is an important factor in
irrigation water quality evaluation and excessive sodium leads to development of an
alkaline soil that can cause soil physical
problems and reducing soil permeability. The
concentration of the sodium permissible
limit of the treated wastewater for irrigation
is about 10.87 meq/L (250 mg/L) (Shakir et
al., 2016).
3.3.3. Nitrate (NO3)
Nitrate is naturally occurring ions that
are part of the nitrogen cycle, the nitrate ion
(NO3) is the stable form of combined nitrogen
for oxygenated systems (Tyagi et al., 2018).
Results indicated that Nitrate NO3
values was 0.225 mg/L for TWW lower than
usual limits 50 mg/L, stated by (FAO, 1992).
The reason nitrate exists in TWW is
because they are at the permissible level and
lower than source water. During the
biological treatment process, total nitrogen is
converted
in
cell
synthesis
by
ammonification, then removed during the
sedimentation process (Horan, 1989).
3.3.4. Total Kjeldahl Nitrogen (TKN)
According to the EPA definition, Total Nitrogen equals to Total Kjeldahl Nitrogen
(TKN) plus nitrate plus nitrite (Redmond et al.
2014). The values of TKN were 107.70 mg/L
for TWW effluent of RWWTP. These results
are in excess of the acceptable range
assigned as PS 224/2003 that the reference
standard for irrigation water quality is reported to be 50 mg/L.

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3.3.5. Ammonium (NH4)
It was clearly noticed NH4 value for TWW
effluent was 126.80 mg/L. These results were
higher than FAO (1992) standard reaching
the value of between 0 and 40 mg/L.
3.3.6. Phosphorus (P)
Phosphorus is absorbed by plant roots in
the orthophosphate form, the values of
phosphorus was 17.9 mg/L for TWW of
RWWTP. According to (FAO, 1992), the
maximum permissible Phosphorus value is 30
mg/L. Results indicated that P was within
guidelines values, these values indicate low
degree of detergent exist in TWW within
allowable range.
3.4. Biochemical and Chemical Oxygen
Demands (BOD5 and COD)
The BOD5values for TWW of RWWTP
was 110 mg/L, Also COD values was 250
mg/L. In comparison to both value of BOD
and COD to meet (FAO, 1992), these results
is excess the acceptable range.
3.5. Biological Parameters
Fecal and total coliform (FC) was investigated as indicator parameters for biological
characteristics of wastewater. Results of
treated wastewater of RWWTP show that fecal Coliform Bacteria equal 620,000 CFU/100
mL. That means high risk of pathogen presence, and it is much higher than FAO (1992)
standards.
3.6. Heavy Metal (HM)
Apart from Petrol, lead (Pb) in
wastewater comes from recycled batteries,
storage tank linings and corrosive liquid tanks
paints, and antibacterial and wood preservatives. On the other hand, Cadmium (Cd)
comes from industrial sources such as galvanizing. Household sources include disposal
batteries, traffic sources such as tires and oil,
and farming sources because cadmium is
used to treat poultry infected by parasitic

Husam Al-Najar &. Basel EL Hamarneh. The Effect of Education Level on Accepting...| 34

worms (Dojlido and Best, 1993). The results
of effluent Cd, Pb, Cu are in the range of FAO
(1992) standards.

3.7. Relationship between Education Level
and Acceptance of Using Treated
Wastewater for Irrigation

Khaskhoussy et al. (2015) stated that
Treated
wastewater
(TWW)
may
contain toxic chemical constituents that
pose negative environmental and health
impacts. The TWW irrigation increased
significantly (P ≤ 0.05) on the soils’ EC, Na, K,
Ca, Mg, Cl, SAR, Cu, Cd, and Ni and had no
significant effect (P ≤ 0.05) on the soils’ pH,
Zn, Co, and Pb contents. EC, Na, Cl, SAR,
Zn, and Co increased significantly with soil
depth. These elements are important to be
clarified for gaining good analysis results.

Table 2 shows the relation between education levels and acceptance of using
treated wastewater for irrigation. Based on
the Chi-square test analysis, there was an assumption that two variables are independent. The result showed that P-value =0.00095
< α= 0.05, so the null hypothesis (variables
are related) was rejected. This means that
there is a close relationship between the educational level in Rafah governorate and acceptance of using treated wastewater in irrigation, as long as they are safe and healthy,
as supported by Deek et al. (2010). There are
differences in statistical significance that
people with more education have more acceptance of using treated wastewater.

Table2. The relation between education level and acceptance of using treated
wastewater for irrigation
Acceptance of using treated wastewater for irrigation

Education Level

Uneducated
Elementary School
Preparatory School
Secondary
Diploma
University graduate and over

3.8. The Relation between Participating in
Environmental Awareness Programs to
Reuse Treated Wastewater and
Educational Level
Table 3 shows the relation between participating in environmental awareness programs to reuse treated wastewater and educational level by using Chi-square test analysis with the assumption of two variables are
independent. P-value =0.0015< α= 0.05, so
the null hypothesis (variables are related) is
rejected. This means that there is a close re-

Yes
No
Total
Freq. Perc. Freq. Perc.
12 17.1% 11 10.7% 23
14 12.0%
7
25.0% 21
28 17.1%
3
39.3% 31
29 24.8%
4
14.3% 33
26 22.2%
2
7.1%
28
8
6.8%
1
3.6%
9

lationship between participating in environmental awareness programs to reuse treated
wastewater and educational level. Adewumi
and Oguntuase (2016) stated that
environment programs was very useful to
enhanced
wastewater
reuse
where
wastewater reuse will form an important
component of water sources in addition to
surface and groundwater sources. It will also
eliminate the pollution effects of
indiscriminate disposal into sensitive
ecosystems.

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In conclusion, The reuse of RWW is a major priority to meet the increase water demands of the agricultural sector due to water
scarcity in Gaza Strip.
Current wastewater effluent from
RWWTP is unsuitable for irrigation due to the
higher concentration of BOD, COD, TKN, Na,
Mg, Cl, SAR, TSS, FC, and TDS these concentrations are above the permissible limit according to the Palestinian standards, but parameters (NH4, NO3, P, Ca, pH, Cd, Pb, and Cu)
still in allowable range. The use of treated
wastewater for irrigation of all social, cultural, and environmental aspect is feasible
but in contrast with a technical standpoint
because RWWTP needs improvement to
meet PS standards. However, after installing
a sand filter, it will be technically possible.
The researcher found that most of the farmers, about 80.70%, would accept using
treated wastewater in irrigation. The highest

yield was the most relevant reason for accepting the use of treated wastewater because of increasing salinity level in the local
agricultural wells, increasing fuel price, and
maintenance cost. Robbie et al. (2017) stated
that water treatment plus reuse in urban
farms can enhance GHG mitigation and also
directly save groundwater. However, very
large amounts of land are needed to extract
nutrients from dilute effluents.
Moreover, there is a close relationship
between education level and acceptance of
using treated wastewater for irrigation. The
researcher believes that these public awareness campaigns contribute to the sustainability of the treated wastewater projects and reuse of the treated wastewater for irrigation.
There is also a close relationship between
participating in environmental awareness
programs to reuse treated wastewater and
educational level.

Table3. The relation between participating in environmental awareness programs to reuse treated wastewater and educational level
Participating in environmental awareness programs to reuse treated wastewater
Educational level

Yes

No

Total

Frequency

%

Frequency

%

Uneducated

18

15.8%

5

16.1%

23

Elementary School

15

13.2%

6

19.4%

21

Preparatory School

17

14.9%

14

45.2%

31

Secondary

28

24.6%

5

16.1%

33

Diploma

27

23.7%

1

3.2%

28

University graduate and over

9

7.9%

0

0.0%

9

4. CONCLUSION
The BOD, COD, TKN, NH4, NO3, and P
accounted for 110, 250, 108, 127, 0.23, 17.90
mg/L, respectively. Then, the concentration
of , Cd, Pb, and Cu were <0.003, <0.001, and
19.90 µg/L, respectively. Most of reuse
parameters were higher than the
recommended levels for the effluent reuse
based on the recommended Palestinian
Standards for irrigation. About 80.70% of
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farmers accept using treated wastewater in
irrigation and the Chi-square test analysis
showed that at P-value =0.00095 < α = 0.05,
there is a close relationship between the
educational level of farmers and the
acceptance of using of treated wastewater in
irrigation, as long as they are safe and
healthy.

Husam Al-Najar &. Basel EL Hamarneh. The Effect of Education Level on Accepting...| 36

5. ACKNOWLEDGEMENTS

6. AUTHORS’ NOTE

The authors would like to express their thanks
to Colaboration research between The Islamic
Gaza (Gaza Strip, Palestina) and Universitas
Negeri Surabaya (Surabaya, Indonesia).

The authors declares that there is no
conflict of interest regarding the publication
of this article. Authors confirmed that the
data and the paper are free of plagiarism.

6. REFERENCES
Abu Jabal, M.S., Abustan, I., Rozaimy, M.R. and H. Al-Najar. (2018). The deuterium and
oxygen-18 isotopic composition of the groundwater in Khan Younis City, southern
Gaza Strip (Palestine). Environ Earth Sci. 77: 155.
Adewumi, J. R., and Oguntuase, A. M. (2016). Planning of Wastewater Reuse Programme in
Nigeria. Consilience: The Journal of Sustainable Development Vol. 15, Iss. 1 (2016), Pp.
1-33.
APHA (2005). American Public Health Association. Standard methods for the examination of
water and wastewater. American Public Health Association (APHA): Washington, DC,
USA.
Bartlett, J. E., Kotrlik, J. W., and Higgins, C. C. (2001). Organizational research: Determining
appropriate sample size in survey research. Information technology, learning, and
performance journal, 19(1), 43.
Biggam, J. (2015). Succeeding with your master's dissertation: a step-by-step handbook.
McGraw-Hill Education (UK).
Creative research system (2014). Sample Size Formulas. Available from:
http://www.surveysystem.com/sample-size-formula.htm [Accessed on: 11/09/2014].
DataStar (2008). Inc. Report, What Every Researcher Should Know About Statistical
Significance
(October
2008).
Retrieved
from
http://www.surveystar.com/startips/oct2008.pdf.
Deek Z., Abu Madi M., Al-Saad (2010): "Rural residents of Ramallah and Al-Bireh accept the
use of treated wastewater." research seminar. Birzeit University.
Dojlido, J., and Best, G. A. (1993). Chemistry of water and water pollution. Ellis Horwood
Limited.
EPA, U. (2004). Guidelines for water reuse. Washington, DC, 450
FAO (2012) Water quality for agriculture. FAO Irrigation and drainage paper 29 Rev. 1. Food
and Agricultural Organization. Rome, 1, 74.
Fatta, D., Arslan Alaton, I., Gokcay, C., Rusan, M. M., Assobhei, O., Mountadar, M., and
Papadopoulos, A. (2005). Wastewater reuse: problems and challenges in Cyprus,
Turkey, Jordan and Morocco. European water, 11(12), 63-69.

DOI:http://dx.doi.org/10.17509/ijost.v4i1.14881|
p- ISSN 2528-1410 e- ISSN 2527-8045 |

37| Indonesian Journal of Science and Technology,Volume 4Issue 1, April 2019 Page 28-38

Fellows, R.F. and Liu, A.M.M. (2008). Research Methods for Construction. 3rd Edition. Oxford:
Wiley-Blackwell.
Horan, N. J. (1989). Biological wastewater treatment systems: theory and operation. John
Wiley and Sons Ltd.
Johnson, P., and Duberley, J. (2000). Understanding management research: An introduction
to epistemology. Sage.
Khaskhoussy, K., Jozdan, O., Kahlaoui, B., Nefzi, B. M., Dakheel, A., and Hachicha, M. (2015).
Effect of Treated Wastewater Irrigation on Heavy Metals Distribution in a Tunisian Soil.
Engineering, Technology and Applied Science Research. Vol. 5, No. 3, 2015, 805-810.
Kothari, C. R. (2004). Research methodology: Methods and techniques. New Age International
Malhotra, N., and Birks, D. (2007). Marketing Research: an applied approach: 3rd European
Edition.
Martin, P. L. (2015). Managing international labor migration in the 21st century. SouthEastern Europe Journal of Economics, 1(1).
Mbarki, S., Cerdà, A., Zivcak, M., Brestic, M., Rabhi, M., Mezni, M., ... & Pascual, J. A. (2018).
Alfalfa crops amended with MSW compost can compensate the effect of salty water
irrigation depending on the soil texture. Process Safety and Environmental
Protection, 115, 8-16.
Naing, L., Winn, T., and Rusli, B. N. (2006). Practical issues in calculating the sample size for
prevalence studies. Archives of orofacial Sciences, 1, 9-14.
Palestinian Central Bureau of Statistics (PCBS). 2016. Socio-Economic and Food Security
Survey.
Pescod, M. B. (1992). Wastewater treatment and use in agriculture.
PWA (2015). Water Resources Status Summary Report /Gaza Strip, Water
Redmond, E. D., Just, C. L., and Parkin, G. F. (2014). Nitrogen removal from wastewater by an
aerated subsurface-flow constructed wetland in cold climates. Water Environment
Research, 86(4), 305-313.
Robbie, L. M.,Ramaswami, A., and Amerasinghe. P. (2017). Wastewater treatment and reuse
in urban agriculture: exploringthe food, energy, water, and health nexus in
Hyderabad, India. Environ. Res. Lett.12 (2017) 075005
Saunders, M., Lewis, P. and Thornhill, A. (2009). Research methods for business students. 5th
Edition. Harlow: Pearson Education.
Shakir, E., Zahraw, Z., Al-Obaidy, A. H. M. J. (2017). Environmental and health risks associated
with reuse of wastewater for irrigation. Egyptian Journal of Petroleum. 26, 95–102
Shomar, B. (2006). Groundwater of the Gaza Strip: is it drinkable? Environmental Geology,
50(5), 743-751.

| DOI:http://dx.doi.org/10.17509/ijost.v4i1.14881
| p- ISSN 2528-1410 e- ISSN 2527-8045

Husam Al-Najar &. Basel EL Hamarneh. The Effect of Education Level on Accepting...| 38

Shomar, B. H., Müller, G., and Yahya, A. (2005). Geochemical characterization of soil and
water from a wastewater treatment plant in Gaza. Soil and Sediment Contamination,
14(4), 309-327.
Shomar, B., Fakher, S. A., and Yahya, A. (2010). Assessment of groundwater quality in the Gaza
Strip, Palestine using GIS mapping. Journal of Water Resource and Protection, 2(2), 93.
Tayie, S. (2005). Research methods and writing research proposals. Pathways to Higher
Education.
Tyagi, S., Rawtani, D., Khatri, N., and Tharmavaram, M. (2018). Strategies for Nitrate removal
from aqueous environment using Nanotechnology: A Review. Journal of Water Process
Engineering, 21, 84-95.
Vaus, D. D. (2002). Surveys in social research (5th Edition). New South Wales: Allen and Unwin.
Zikmund, W. G., Babin, B. J., Carr, J. C., and Griffin, M. (2009). Business Research Methods 8th
(Eight) Edition. New Castle: South-Western College Pub.

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