Highly even community structure and rich diversity of microbes contribute to efficient treatment of the plants
Immediately after commencement of first ever sewage treatment plant, it was evident that wastewater treatment facilities would serve as a crucial barrier between anthropogenic activities and environment. As stated in one of the UN reports, “roughly 83 million people being added to the world’s population every year” (world-population-prospects-2017), the proportional increase in commodity demand is also expected to be observed. That in-turn will lead to generation of much higher amount of effluent than being treated all over the globe. Advancement of technologies and increase in span of product reach also implies that, not just industries, but effluent treatment community will have to deal with transitions and fluctuations on daily bases. Are we really ready for that? The answer is, to meet new permissible limits, pace of growth and environmental protection policies it is required to come up with innovative, efficient, market viable solutions from research end. The solution lies in microbial community composition present in the sewage or industrial wastewater treatment plant.
Apart from meeting these legislative requirements, plant operation experts face a lot of issues like; excess foam formation, low sludge volume index, low MLSS (in case of industrial effluent treatment plants), slurry formation, unhealthy floc formation and foul smell at various days of the year. If we look into matter of each specific case, microbial community composition holds the key for resolving everyday troubles too.
In this article I would like to brief readers about following points
• What are microbial community and its structure?
• How its composition affects wastewater treatment efficiency?
• General measures affecting composition
• How do we take advantage of useful microbes?
Wastewater treatment plants are one of the finest examples of microbes (aerobes and anaerobes) being put to work for benefit of human race. Amongst most popular technologies, anaerobic treatment options do serve purpose of removal of toxic material, but fails to meet lower HRT desired in most cases. This limitation can be overcome by aerobic treatment technologies easily due to rapid growth rate of aerobic microbes. However, this condition can only be achieved if the microbial community composition is the best suitable for the wastewater type being treated. It is required to understand that while dealing with aerobic microbial treatment schemes, a single change form optimum parameter will generate direct impact on treatment efficiency. During the biological treatment, group of microorganisms which act on organic waste for its oxidation and the community developed during the processes of CETP holds the key for the efficient functioning of the plant (Forster et al. 2003). Let us try to understand interplay of wastewater and microbes at large using basic microbiological understanding.
The term “Microbial community” refers to assemblage of variety of species of microorganisms living together in the same niche/space/ecosystem/matrices. As illustrated in figure 1, a single organism of single type is normally referred as presence of species A or B. Organism of the same species in bulk is referred as population of species A or B. In a particular habitat, assemblage of multiple numbers of species in billions of numbers is thus referred as community in this article.