Photo-bioreactor - Norezatul Shahirah bt Ahmad Zamanhuri
WASTE WATER TREATMENT
Norezatul Shahirah bt Ahmad Zamanhuri
• A photobioreactor is a algae bioreactor that utilizes a light source to
cultivate phototropic microorganisms.
• These organisms use photosynthesis to generate biomass from light and
• Within the artificial environment of a photobioreactor, specific conditions
are carefully controlled for respective species.
• Thus, a photobioreactor allows much higher growth rates and purity levels
than anywhere in nature or habitats similar to nature.
• Hypothetically, phototropic biomass could be derived from nutrient-rich
wastewater and flue gas carbon dioxide in a photobioreactor.
• The first approach for the controlled production of phototrophic organisms was and
still is a natural open pond or artificial raceway pond.
• Therein, the culture suspension, which contains all necessary nutrients and carbon
dioxide, is pumped around in a cycle, being directly illuminated from sunlight via
the liquid’s surface.
• This construction principle is the simplest way of production for phototrophic
organisms. But due to their depth (up to 0.3 m) and the related reduced average
light supply, open systems only reach limited areal productivity rates.
• In addition, the consumption of energy is relatively high, as high amounts of water
containing low product concentration have to be processed.
• Open space is expensive in areas with a dense population, while water is rare in
• Using open technologies causes high losses of water due to evaporation into the
• Since the 1950s several approaches have been conducted to develop closed
systems, which theoretically provide higher cell densities of phototrophic organisms
and therefore a lower demand of water to be pumped than open systems.
• In addition, closed construction avoids system-related water losses and the risk of
contamination through landing water birds or dust is minimized.
• All modern photobioreactors have tried to balance between a thin layer of culture
suspension, optimized light application, low pumping energy consumption, capital
expenditure and microbial purity.
• Many different systems have been tested, but only a few approaches were able to
perform at an industrial scale.
• Example of the closed system of photobioreactor which are Redesigned laboratory
fermenters, Tubular photobioreactors, Christmas tree photobioreactor, and
• decomposition of organic matter by
aerobic bacteria takes place.
• To intensify the process of cleaning, a
pool filled with plastic filler with a large
surface area that is filled with aerobic
• Then the sewage get into the photo-
bioreactor with phytoplankton .
• Under the influence of light and
nutrients, the amount of biomass of
phytoplankton in a photo-bioreactor
• Then absorption of carbon dioxide and
release of oxygen takes place.
• Removal of phytoplankton biomass
from the water can be carried out by
separators and filters .
• Purified waste water goes through the
fish and household pool used for
bioindication of water quality.
• Since fish can bioaccumulate toxic
substances, then analysing the contents
of their internal organs may evaluate
the integral level of toxicity of
wastewater over a period of time.
• Prevent or minimize contamination
• Offer better control over existing conditions (pH, light, carbon dioxide, temperature).
• Prevent water evaporation,
• Lower carbon dioxide losses due to out gassing,
• Permit higher cell concentrations.
• Allow you to grow algae in any climate