Physical and chemical properties of the TWW before the aeration post-treatment, compared to the FAO recommendations on the degree of restriction for TWW reuse for irrigation and to the ISO 16075 standard
| Parameter . | Value in the TWW . | FAO degree of restriction for TWW use for irrigationa . | ISO 16075 guideline for TWW reuse for irrigationb . | ||
|---|---|---|---|---|---|
| None . | Slight to moderate . | Severe . | |||
| pH | 7.44 ± 0.02 | Normal range: 6.5–8 | |||
| EC (dS/m) | 3.55 ± 0.09 | <0.7 | 0.7–3.0 | >3.0 | |
| CO32− (mg/l) | 0 | ||||
| HCO3− (mg/l) | 576 ± 23 | <92 | 92–519 | >519 | |
| Ca2+ (mg/l) | 139 ± 4 | ||||
| Mg2+ (mg/l) | 51 ± 2 | ||||
| Cl− (mg/l) | 666 ± 26 | <142c | >142c | ||
| Na+ (mg/l) | 203 ± 6 | <69c | >69c | ||
| K+ (mg/l) | 45 ± 2 | ||||
| NH4+ (mg/L) | 1.8 ± 0.1 | ||||
| P (mg/L) | 0.90 ± 0.04 | ||||
| NO3-N (mg/L) | 55 ± 3 | <5 | 5–30 | >30 | |
| Organic matter (mg/L) | 150 ± 8 | ||||
| 5-day biochemical oxygen demand (mg/L) | 12 ± 1 | <35 | |||
| Total suspended solids (mg/L) | 12 ± 1 | <50 | |||
| Thermo-tolerant coliforms (n./100 mL) | 60 ± 6 | <10,000 | |||
| Total dissolved solids (mg/L) | 2 595 ± 180 | <450 | 450–2,000 | >2,000 | |
| Parameter . | Value in the TWW . | FAO degree of restriction for TWW use for irrigationa . | ISO 16075 guideline for TWW reuse for irrigationb . | ||
|---|---|---|---|---|---|
| None . | Slight to moderate . | Severe . | |||
| pH | 7.44 ± 0.02 | Normal range: 6.5–8 | |||
| EC (dS/m) | 3.55 ± 0.09 | <0.7 | 0.7–3.0 | >3.0 | |
| CO32− (mg/l) | 0 | ||||
| HCO3− (mg/l) | 576 ± 23 | <92 | 92–519 | >519 | |
| Ca2+ (mg/l) | 139 ± 4 | ||||
| Mg2+ (mg/l) | 51 ± 2 | ||||
| Cl− (mg/l) | 666 ± 26 | <142c | >142c | ||
| Na+ (mg/l) | 203 ± 6 | <69c | >69c | ||
| K+ (mg/l) | 45 ± 2 | ||||
| NH4+ (mg/L) | 1.8 ± 0.1 | ||||
| P (mg/L) | 0.90 ± 0.04 | ||||
| NO3-N (mg/L) | 55 ± 3 | <5 | 5–30 | >30 | |
| Organic matter (mg/L) | 150 ± 8 | ||||
| 5-day biochemical oxygen demand (mg/L) | 12 ± 1 | <35 | |||
| Total suspended solids (mg/L) | 12 ± 1 | <50 | |||
| Thermo-tolerant coliforms (n./100 mL) | 60 ± 6 | <10,000 | |||
| Total dissolved solids (mg/L) | 2 595 ± 180 | <450 | 450–2,000 | >2,000 | |
aAyers & Westcot (1985).
bValues corresponding to category C (irrigation of non-food crops) of the ISO 16075 standard (ISO 2015).
cRefers to the case of sprinkler irrigation.