ENVIRONMENT AND ENERGY
21
<< Continued from page 19
operational costs decrease. Membrane bioreactors
(MBRs) are an emerging technology, resulting from
innovations to intensify the membrane separation by
incorporating it with the activated sludge process.
Recently, the number of plants with MBR technology
is on the rise. MBRs offer advantages such as
compactness, flexibility, and ability to operate reliably
under remote control.
Microbial fuel cells, a technological innovation based
on bio-electrochemical processes of bacteria, have
started to find applications in wastewater treatment over
the past decade, in order to harvest energy (electrical
current) by utilising anaerobic digestion that mimics
bacterial interactions found in nature. This technology
can significantly reduce treatment process costs and the
amount of leftover sludge. However, given the challenges
in scaling up for practical application, further research
and technological improvements are needed to overcome
the high energy requirements.
New developments in biological treatment processes
have found successful application due to the high
efficiencies and low investment and operational costs.
Examples include innovative processes for improved
nitrogen removal such as SHARON® (single reactor
system for high-activity ammonium removal over
nitrite), ANAMMOX® (anaerobic ammonium oxidation)
and BABE® (bio augmentation batch enhanced), as
well as mineral crystallisation processes for phosphorus
recovery and reuse. Granular sludge treatment
processes are also emerging by using engineered
microbial structures. The first granular sludge process
is commercialised under the name of NEREDA®.
Nanotechnology is an emerging and growing field with
potentially promising applications in water purification
and wastewater treatment, as well as in water quality
and wastewater monitoring. Presently, nanotechnology
applications in water and wastewater treatment focus
on technology maturation and full-scale demonstration.
Innovative wastewater monitoring and control systems
are finding application as technologies improve. The
most promising technological advances include:
innovative monitoring techniques based on new sensors,
computerised telemetry devices, and innovative data
analysis tools. Research on sensor and system control is
advancing rapidly. New methods to control wastewater
treatment are continually introduced, including the use of
mobile applications to operate the SCADA (Supervisory
Control and Data Acquisition) system for remote
monitoring and control of wastewater systems.
Natural treatment systems (constructed wetland
systems) are becoming more attractive as innovative
natural solutions to complement existing technological
limitations, with research increasingly focusing on
natural processes. Modelling has become an important
aspect of new research developments in the field of
www.plumbingafrica.co.za
wastewater, as fundamental knowledge on microbiology
and biochemistry advances and the computational
capacity improves. Modelling not only allows the transfer
of scientific knowledge to practical applications, but also
facilitates the communication between scientists and
engineers at a global level.
BARRIERS TO RESEARCH, INNOVATION,
AND TECHNOLOGY APPLICATIONS
Lack of financing is a major barrier for the application of
existing technologies in developing countries, but also for
the promotion of research and the transitioning of new
technologies for large-scale applications in developed
countries. The high costs of high-end technologies
hamper their widespread application, especially in
developing countries.
Furthermore, a limited market niche for new technology
applications halters innovation. The limited knowledge
about the market for products recovered from wastewater
adds to this challenge. Scarce data and information on
wastewater form another major impediment to research
and innovation, as is the (often-missing) link between the
academia, industry, and local government. Translating
innovation into practical application requires research into
financing opportunities and into ways to create a market
niche for new technologies, building human and technical
capacities, and engaging stakeholders, including the
private sector. This can be enabled through strong political
will and government support.
FUTURE TRENDS IN WASTEWATER MANAGEMENT
Whereas past innovation in the field of wastewater
focused mainly on advanced treatment technologies,
new and innovative solutions are emerging, combining
both technological and management aspects. Future
trends in wastewater management increasingly focus
on water reuse and resource recovery, which provide
the additional benefits of safeguarding public health and
reducing environmental pollution. For example, water
reuse, the creation of commercial (phosphorus) fertilisers
and in particular energy recovery, can significantly lower
operation and maintenance costs.
Innovative wastewater management solutions that
incorporate interdisciplinary and integrated approaches
are also becoming more common and an area of growing
research interest. Decentralisation at an appropriate level,
combining centralised and decentralised solutions, is also
appearing as a potential alternative, transitioning from
oversized, centralised water and wastewater facilities, to
infrastructure at a more adequate management scale.
SHIFTING FROM WASTEWATER TREATMENT TO
WATER REUSE AND RESOURCE RECOVERY
The technological advances in wastewater treatment over
the past decades have presented an opportunity to shift the
primary o bjective of wastewater management from ‘treat
and dispose’ to ‘reuse, recycle, and recover resources’.
Key research issues
in this area include:
cost-effectiveness,
consumer behaviour,
acceptance
and incentives,
business models,
and institutional
arrangements.
June 2018 Volume 24 I Number 4