aerated wetland technology and the feasibility of these systems even in harsh
environments.
Keywords
Constructed wetlands · Vertical flow · Aerated wetland · Domestic wastewater ·
Hybrid system · Wastewater reuse
7.1
Introduction
Natural processes have been used in waste/wastewater treatment processes for a long
time; the most known technologies and methods utilize these processes, for example,
sedimentation, filtration, biological activity, etc., under intensified conditions; hence
they typically include complex and energy-consuming mechanical equipment.
The main difference that separates the so-called natural treatment systems from the
conventional ones is that only natural components and processes are used for the
treatment. Naturally occurring processes are utilized under a controlled environment
in natural treatment systems, without the need for external energy input for these
processes to occur. Typically, energy is consumed only for few mechanical parts,
e.g., pump operation. Among the various natural treatment systems, such as waste
stabilization ponds, constructed wetlands (CWs) appear as one of the most
promising eco-tech methods, which have been attracting increasing worldwide
interest. Their excellent treatment performance, combined with their environmentally friendly (ecological) character and the typically reduced overall costs, has
placed constructed wetlands in the forefront of the scientific and marketing interest
(Stefanakis 2019, 2020).
CWs are already an established ecological treatment method for municipal
(Stefanakis et al. 2014; Stefanakis 2015) and various industrial wastewaters
(Wu et al. 2015; Stefanakis 2018; Stefanakis et al. 2019). The main driver for the
tremendous expansion of applications worldwide and the intensification of international research is the multiple advantages these systems offer compared to conventional treatment methods such as activated sludge systems or membrane bioreactors.
Conventional and mechanical treatment methods are used for more than a
century, based on a different approach of wastewater treatment, which consists in
the installation of large, centralized facilities and respectively extended sewer
networks for the collection and transport of wastewater from its source. This
translates to large end-of-the-pipe centralized wastewater treatment facilities and a
related long sewer network, with respectively high required investment. These
facilities are also typically characterized by high operation and maintenance costs
(Stefanakis 2015). It is true that such facilities provide a wastewater treatment
solution for large cities, capitals and populated urban areas. For that perspective,
the high investment cost is difficult to avoid. The question that arises is whether this
centralized approach is a proper and feasible solution for smaller cities, communities
196
A. I. Stefanakis
environments.
Keywords
Constructed wetlands · Vertical flow · Aerated wetland · Domestic wastewater ·
Hybrid system · Wastewater reuse
7.1
Introduction
Natural processes have been used in waste/wastewater treatment processes for a long
time; the most known technologies and methods utilize these processes, for example,
sedimentation, filtration, biological activity, etc., under intensified conditions; hence
they typically include complex and energy-consuming mechanical equipment.
The main difference that separates the so-called natural treatment systems from the
conventional ones is that only natural components and processes are used for the
treatment. Naturally occurring processes are utilized under a controlled environment
in natural treatment systems, without the need for external energy input for these
processes to occur. Typically, energy is consumed only for few mechanical parts,
e.g., pump operation. Among the various natural treatment systems, such as waste
stabilization ponds, constructed wetlands (CWs) appear as one of the most
promising eco-tech methods, which have been attracting increasing worldwide
interest. Their excellent treatment performance, combined with their environmentally friendly (ecological) character and the typically reduced overall costs, has
placed constructed wetlands in the forefront of the scientific and marketing interest
(Stefanakis 2019, 2020).
CWs are already an established ecological treatment method for municipal
(Stefanakis et al. 2014; Stefanakis 2015) and various industrial wastewaters
(Wu et al. 2015; Stefanakis 2018; Stefanakis et al. 2019). The main driver for the
tremendous expansion of applications worldwide and the intensification of international research is the multiple advantages these systems offer compared to conventional treatment methods such as activated sludge systems or membrane bioreactors.
Conventional and mechanical treatment methods are used for more than a
century, based on a different approach of wastewater treatment, which consists in
the installation of large, centralized facilities and respectively extended sewer
networks for the collection and transport of wastewater from its source. This
translates to large end-of-the-pipe centralized wastewater treatment facilities and a
related long sewer network, with respectively high required investment. These
facilities are also typically characterized by high operation and maintenance costs
(Stefanakis 2015). It is true that such facilities provide a wastewater treatment
solution for large cities, capitals and populated urban areas. For that perspective,
the high investment cost is difficult to avoid. The question that arises is whether this
centralized approach is a proper and feasible solution for smaller cities, communities
196
A. I. Stefanakis