11 Ranking of Natural Wastewater Treatment Techniques …
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could efficiently remove phosphorous, nitrogen, suspended solids, sulfur, and heavy
metals (Laitinen et al. 2017).
11.2.3 Use of Aquatic Plants
In this natural wastewater treatment method, vegetation grown on the aquatic environment is used as a wastewater treatment technique. In this treatment method,
floating or submerged plant species such as reed, water hyacinth, duckweed, and
pondweed are used to absorb and remediate heavy metals and organic nutrients;
hence it could increase treatment performance of the method (Qian et al. 2007). The
role of aquatic plants in wastewater treatment is mainly bacterial transformation and
physical, chemical processes such as precipitation, adsorption, and sedimentation
(Gersberg et al. 1986). Aquatic plants can transport oxygen from shoot to root zone,
hence it will oxidize the environment which could stimulate decay of organic wastes
and growth of nitrifying micro-organisms. The increased population of nitrifying
micro-organisms can easily convert ammonia into nitrate. The newly formed nitrate
will be removed from the system through denitrification.
11.2.4 Reuse of Wastewater for Irrigation
Reuse of wastewater for agriculture significantly improve the quality of wastewater
as it applied to the soil, the organic pollutants in the wastewater are consumed as nutrients by crops (Akber et al. 2008). Recycling of wastewater for irrigated agriculture
is useful for crop producers in the conservation of freshwater, increases the nutrient
content of the soil, and reduces surface and groundwater pollution since it is sifted
through the soil when irrigated. Raw wastewater is applied to household irrigations
in uncontrolled sectors that can help farmers who cannot afford fresh water. Farmers
opt to utilize wastewater to save costs paid to buy fertilizers (Corcoran et al. 2010)
because the wastewater is reaching with essential nutrients, for example, 50 mg/L of
nitrogen, 10 mg/L phosphorus and 30 mg/L of potassium.
11.2.5 Soil Filters
Soil filter is a cheap natural wastewater treatment method that could improve the
quality of wastewater while it seeps through the soil (Akber et al. 2008). In this
wastewater treatment method, soil plays natural purifying roles (Rozkosny et al.
2014) which is designed to allow water flow through the media both vertically and
horizontally. Soil filters are cylindrical or prismatic in shape which is made up of
concrete mixture or plastic materials and the soil is excavated by waterproof materials
91
could efficiently remove phosphorous, nitrogen, suspended solids, sulfur, and heavy
metals (Laitinen et al. 2017).
11.2.3 Use of Aquatic Plants
In this natural wastewater treatment method, vegetation grown on the aquatic environment is used as a wastewater treatment technique. In this treatment method,
floating or submerged plant species such as reed, water hyacinth, duckweed, and
pondweed are used to absorb and remediate heavy metals and organic nutrients;
hence it could increase treatment performance of the method (Qian et al. 2007). The
role of aquatic plants in wastewater treatment is mainly bacterial transformation and
physical, chemical processes such as precipitation, adsorption, and sedimentation
(Gersberg et al. 1986). Aquatic plants can transport oxygen from shoot to root zone,
hence it will oxidize the environment which could stimulate decay of organic wastes
and growth of nitrifying micro-organisms. The increased population of nitrifying
micro-organisms can easily convert ammonia into nitrate. The newly formed nitrate
will be removed from the system through denitrification.
11.2.4 Reuse of Wastewater for Irrigation
Reuse of wastewater for agriculture significantly improve the quality of wastewater
as it applied to the soil, the organic pollutants in the wastewater are consumed as nutrients by crops (Akber et al. 2008). Recycling of wastewater for irrigated agriculture
is useful for crop producers in the conservation of freshwater, increases the nutrient
content of the soil, and reduces surface and groundwater pollution since it is sifted
through the soil when irrigated. Raw wastewater is applied to household irrigations
in uncontrolled sectors that can help farmers who cannot afford fresh water. Farmers
opt to utilize wastewater to save costs paid to buy fertilizers (Corcoran et al. 2010)
because the wastewater is reaching with essential nutrients, for example, 50 mg/L of
nitrogen, 10 mg/L phosphorus and 30 mg/L of potassium.
11.2.5 Soil Filters
Soil filter is a cheap natural wastewater treatment method that could improve the
quality of wastewater while it seeps through the soil (Akber et al. 2008). In this
wastewater treatment method, soil plays natural purifying roles (Rozkosny et al.
2014) which is designed to allow water flow through the media both vertically and
horizontally. Soil filters are cylindrical or prismatic in shape which is made up of
concrete mixture or plastic materials and the soil is excavated by waterproof materials