Characteristics TWW TW Tunisian regulation
pH 7.60 ± 0.10 7.51 ± 0.11 6.50-8.50
EC 5.6 ± 0.02 4.30 ± 0.03 7
TDS 1.77 ± 0.02 0.93 ± 0.01 2
HCO3ˉ 356.00 ± 0.3 223.30 ± 0.20 600
SO4 354.00 ± 0.7 67.50 ± 1.5 1000
N total 53.80 ± 1.20 - 30
N-NO3ˉ 13.40 ± 0.01 0.97 ± 0.01 -
N-NO4+ 35.6 ± 0.01 2.67 ± 0.04 -
N-NO2ˉ 4.00 ± 0.02 0.04 ± 0.01 -
P total 9.44 ± 0.11 0.45 ± 0.02 0.05
K+ 33.80 ± 0.09 26.00 ± 0.05 50
Na+ 297 ± 0.01 430.00 ± 0.01 300
Clˉ 1767 ± 0.04 1340.00 ± 0.2 600
Ca2+ 98.50 ± 0.01 188.20 ± 0.02 -
Mg2+ 85.70 ± 0.01 126.20 ± 0.03 -
Pb2+ <0.004 0 0.1
Cd2+ <0.004 0 0.005
Zn2+ 0.33 ± 0.01 0.5 ± 0.01 5
Mn2+ 0.65 ± 0.01 0.13 ± 0.03 -
SM 12.20 ± 0.02 2.30 ± 0.02  
COD 74.00 ± 0.01 0 90
BOD5 20.00 ± 0.01 0 30
Total coliforms nd 0 -
Fecal coliforms nd 0 -
Data represents mean values ± standard deviation. EC: electrical conductivity (mS/ cm); TDS: total dissolved solids (g Lˉ1); SM: suspended matter (mg Lˉ1); COD (mg Lˉ1): chemical oxygen demand; BOD5: biological oxygen demand (mg Lˉ1); Total coliform and Fecal coliform (UFC/100 mL). anions, cations and total P and N are measured in (mg Lˉ1); TW: tap water; TWW: treated wastewater; nd, Undetected.
Table 2: Chemical characteristics of the irrigation waters used in the experiment