Membrane Bioreactor

Pressure has been increased on authorities for efficient waste water treatment with environmental consideration due to rapid growth and urbanisation (EU, 2010). Various physical, mechanical, biological and chemical methods of water treatment have been used to remove suspended solids, organic matter and dissolved pollutants or toxins. Membrane bioreactor (MBR) has been regarded as one of the processes in the treatment of waste liquids.

Membrane bioreactor is a combination of biological treatment process and membrane filtration. Membrane is a thin material with a narrow range of pore size and high surface porosity that resist the transfer of different constituents of a fluid (Visvanathan and Aim, 2000). The membrane filters suspended solids and is an alternative for conventional filtration and sand filtration in the treatment of industrial wastewater and municipal sewage (EU, 2010).

Membrane filtration processes are classified according to the membrane pore sizes: microfiltration (0.1 to 10 microns), ultrafiltration (0.003 to 0.1 microns), nanofiltration (0.001 microns) and reverse osmosis (0.0001 microns) (EU, 2010).

Membrane bioreactor has a number of advantages like good effluent quality with high hygienic standards, high possible biomass concentration, reduced reactor volume and footprint and reduced net sludge production (Kraume, 2012).  MBR can provide advanced level of nutrient removal (Fitzgerald, 2008).

 Research is on-going to limit drawbacks associated with MBR. High investment costs of membrane modules, high operating costs associated with energy consumption and membrane integrity are limitations of MBR (Kraume, 2012).

References

European Union (2010) Membrane technologies for water applications Highlights from a selection of European research projects [Online] Available athttp://ec.europa.eu/research/environment/pdf/membrane-technologies.pdf [Accessed on 27 August 2012].

Fitzgerald, K.S. (2008) Membrane bioreactors. [Online] Available at http://www.tsgwater.com/pdf/MBR%20Synopsis.pdf  [Accessed on 27 August2012]

Kraume, M. (2012) Membrane Bioreactors. [Online] Available at http://www.zer0-m.org [Accessed on 27 August 2012].

 Visvanathan, C.  and Aim, B.R.(2000) Membrane Bioreactor Applications in Wastewater Treatment [Online] Available at    http://www.faculty.ait.ac.th/visu/pdfs/Activities/Participation/RMBEE.pdf [Accessed on 27 August 2012].

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Climate Change Adaptation

Policies and strategies to balance climate change consequences are formulated and implemented in adaptation process. The process involves appraisal of climate impacts, preparation for adaptation, application of appropriate actions and evaluation of the acts (UNFCC, 2011). A number of methods and approaches can be found for adaptation planning.Adaptation policies should be holistic and realistic in the real-world situations in which policies are implemented (Mathys, et. al., 2010).

Approaches based on the analysis of existing socio-economic conditions are appropriate for tackling present susceptibilities and adaptive capacity. While scenario and model driven approaches are more suited for estimating climate change impacts, particularly on a large scale. Hazard based approaches assesses existing climate hazards and future climatic risks over time and space using climatic projections. Adaptive capacity approaches assesses the existing adaptive capacity and proposes to increase the strength of adaptive capacity to contest future extremes.

Economic diversification at the national level and livelihood diversification at the community level are some common practices to implement adaptation actions. Engaging policy makers, scientists, administrators, communities, and managers in decision making helps implementing adaptation measures.

Monitoring is important step in the adaptation process which should be carried out during the project implementation and beyond. Monitoring helps planners, policy makers and practitioners to amend and adjust adaptation processes. Efficiency of adaptation process can be assessed by evaluating adaptation action implementation.

Johnston, B.R.; Hiwasaki, L.; Klaver, I.J. and Ramos Castillo, A. (2012) Water, Cultural Diversity, and Global Environmental Change, Emerging Trends, Sustainable Futures? Springer.
Mathys, T.; Strong, A.; Gallagher, K.S., Davidson, N.; Manghani, R.; Wansem, M.V.D. and Moomaw, W. (2010) Key Research Needs for Global Climate Change Policy. [Online] Available at http://fletcher.tufts.edu/ [Accessed on 12 June 2011].
United Nations Framework Convention on Climate Change (UNFCC) (2011) Assessing Climate Change Impacts and Vulnerability, Making Informed Adaptation Decisions. [Online] Available at http://unfccc.int/files/adaptation/application/ [Accessed on 28 July 2011].

Climate Change Adaptation

Freshwater resource has been recognized as an economic good.  Observed and projected climatic changes are likely to increase water stress in the future. Individuals and communities need to be prepared to minimise the negative impacts and maximise the benefits from changes. Autonomous adaptation such as maintaining water supply practices and restoring default or poorly maintained water facilities is supportive to increase adaptive capacity.

Insight of climate probabilities and knowledge of environmental consequences help building long term resilience to impacts. Continuation of research and assessment helps generating scientific knowledge which facilitates decision making for adaptation options.  Development of human capital, strengthening institutional system and good management of public finances and natural resources are necessities for adaptation to future climatic changes.

Individuals and societies are already stressed by globalisation, urbanisation, environmental degradation, disease outbreaks and market uncertainties.  Projected climatic changes and resulting water stress will intensify the condition.  Increasing water supply, expansion of rainwater harvesting, restoration of aquatic habitats, improvement of water-use efficiency by water recycling are possible ways to increase resilience of people and ecosystem.

Integrated water resource management (IWRM) is a precise method to water management.  IWRM aids planning adaptation instruments, co-ordinating land and water resource management, identifying water quality and quantity linkages, combined use of surface and ground water and protecting and restoring natural systems(Mathys, 2010).

Mathys, T.; Strong, A.; Gallagher, K.S., Davidson, N.; Manghani, R.; Wansem, M.V.D. and Moomaw, W. (2010) Key Research Needs for Global Climate Change Policy. [Online] Available at http://fletcher.tufts.edu/ [Accessed on 12 June 2011]