new proposal for European regulation of minimum requirements for water reuse
[4, 5] is currently pending approval by the European Parliament and the European
Council. This new proposal defines, for the first time, the minimum water quality
acceptable for reclaimed water destined for crop irrigation in European Countries.
1.2 Characteristics of the Municipal and Agro-Industrial
Wastewaters
Wastewater effluents can originate as by-products from the civil, industrial, and
agricultural sectors. Following purification, treated wastewater represents an important and readily available water source to meet the increasing demands of crop
irrigation, particularly in water-scarce countries. Indeed, wastewater recycling in
agriculture has gained importance as a component of the agricultural water supply in
some regions (e.g. Mediterranean area) [8].
Wastewater reuse provides significant amounts of irrigation water and helps
reduce the environmental impacts related to the discharge of municipal and/or
agro-industrial effluents into water bodies [8, 9]. Municipal and agro-industrial
wastewater contains approximately 0.1% solid substances, represented by organic
and inorganic solids and microorganisms [10]. The chemical-physical characteristics
of the wastewater effluent depend on its origin and vary with climate, social and
economic situation and with the habits of the population of origin.
Organic substances can include carbohydrates, lignin, fats, proteins and their
decomposition products, as well as various organic chemicals of natural and synthetic origin derived from industrial processes [11].
Inorganic substances include potentially hazardous compounds and heavy metals,
which may be present in wastewater at phytotoxic levels and cause health risks
[11, 12]. In particular, municipal wastewater can contain wastes from domestic,
small-scale craft and livestock activities.
The quality of agro-industrial wastewater is closely related to the type of vegetable products and to the processing systems adopted; such wastewater typically
contains organic substances that are suspended and partly dissolved (sugars, proteins, fats, and residues of plant and animal products).
Agro-industrial wastewaters can contain heavy metals, although the concentrations are unlikely to reach levels dangerous for crops and consumers [13]. Health
risks associated with the use of wastewater for crop irrigation are primarily due to
microbial pathogens (bacteria, viruses, and protozoa) [14, 15]. To mitigate hazards
and damage to human and environment health, wastewater should be adequately
treated before use in irrigation.
The positive or negative effects of treated wastewater application on the soil and
on plants are primarily dependent upon the quality and quantity of the organic and
mineral chemical substances (in particular plant nutrients, such as N, P, K, heavy
metals, and salts) in the solution.
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G. Gatta et al.
[4, 5] is currently pending approval by the European Parliament and the European
Council. This new proposal defines, for the first time, the minimum water quality
acceptable for reclaimed water destined for crop irrigation in European Countries.
1.2 Characteristics of the Municipal and Agro-Industrial
Wastewaters
Wastewater effluents can originate as by-products from the civil, industrial, and
agricultural sectors. Following purification, treated wastewater represents an important and readily available water source to meet the increasing demands of crop
irrigation, particularly in water-scarce countries. Indeed, wastewater recycling in
agriculture has gained importance as a component of the agricultural water supply in
some regions (e.g. Mediterranean area) [8].
Wastewater reuse provides significant amounts of irrigation water and helps
reduce the environmental impacts related to the discharge of municipal and/or
agro-industrial effluents into water bodies [8, 9]. Municipal and agro-industrial
wastewater contains approximately 0.1% solid substances, represented by organic
and inorganic solids and microorganisms [10]. The chemical-physical characteristics
of the wastewater effluent depend on its origin and vary with climate, social and
economic situation and with the habits of the population of origin.
Organic substances can include carbohydrates, lignin, fats, proteins and their
decomposition products, as well as various organic chemicals of natural and synthetic origin derived from industrial processes [11].
Inorganic substances include potentially hazardous compounds and heavy metals,
which may be present in wastewater at phytotoxic levels and cause health risks
[11, 12]. In particular, municipal wastewater can contain wastes from domestic,
small-scale craft and livestock activities.
The quality of agro-industrial wastewater is closely related to the type of vegetable products and to the processing systems adopted; such wastewater typically
contains organic substances that are suspended and partly dissolved (sugars, proteins, fats, and residues of plant and animal products).
Agro-industrial wastewaters can contain heavy metals, although the concentrations are unlikely to reach levels dangerous for crops and consumers [13]. Health
risks associated with the use of wastewater for crop irrigation are primarily due to
microbial pathogens (bacteria, viruses, and protozoa) [14, 15]. To mitigate hazards
and damage to human and environment health, wastewater should be adequately
treated before use in irrigation.
The positive or negative effects of treated wastewater application on the soil and
on plants are primarily dependent upon the quality and quantity of the organic and
mineral chemical substances (in particular plant nutrients, such as N, P, K, heavy
metals, and salts) in the solution.
82
G. Gatta et al.