In this study, microalgae was used to treat wastewater, at the same time,
microalgae used for wastewater treatment was concentrated and separated by
applying DC-MD. This process is a new paradigm that can treat wastewater
and recover sustainable energ...
In this study, microalgae was used to treat wastewater, at the same time,
microalgae used for wastewater treatment was concentrated and separated by
applying DC-MD. This process is a new paradigm that can treat wastewater
and recover sustainable energy. The appropriate concentration of microalgae
was derived from the treatment efficiency and specific growth rate of
microalgae according to the concentration of wastewater, and the possibility of
concentration and separation was estimated. Also examined the influence about
membrane. Microalgae was set to Chlorella Vulgaris in Mixotrophs, wastewater
imitated artificial sewage. In the research, the process was carried out in 3
chapters. In the chapter 1, the specific growth rate and the yield coefficient of
each component were derived by treating low concentration (SCOD 100mg·L-1,
T-N 20mg·L-1, T-P 2mg·L-1) and high concentration (SCOD 400mg·L-1, T-N
40mg·L-1, T-P 10mg·L-1) according to the concentration of microalgae. In the
chapter 2, the use of DC-MD process to concentrate and separate microalgae
was investigated, and in the chapter 3, the possibility that microalgae used for
wastewater treatment was concentrate and separate by applying DC-MD was
evaluated. In the chapter 1, microalgae under all conditions removed each
component (SCOD, T-N, T-P). The maximum specific growth rate (0.21day-1)
was revealed at high concentration (SCOD 400mg·L-1, T-N 40mg·L-1, T-P
10mg·L-1) of artificial sewage. It was 6 times lower than other literatures, and
Yield coefficient corresponding to each component was also measured lower
than the other literatures. Although wastewater treatment is possible through
microalgae, it is judged that the concentration of microalgae can be set lower
than 0.5g·L-1. In order to evaluate the applicability of microalgae concentrationapplied DC-MD, the concentration of microalgae was set at 0.5g·L-1, 1g·L-1,
3g·L-1, the temperature difference between feed and permeate solution was
20oC, 40oC, 60oC, and the cross flow velocity was 0.09m·s-1, 0.18m·s-1. At
3g·L-1 of microalgae, the permeate flux decreased dramatically on the 1day,
and at 1g·L-1 of microalgae, 0.18m·s-1 of the cross flow velocity, wetting
occurred on hydrophobic membrane. At 0.5g·L-1 of microalgae, 40oC of
temperature difference, 0.09m·s-1 of the cross flow velocity, the change in
permeate flux was the least, and at 60oC of temperature difference, 0.18m·s-1
of the cross flow velocity, the concentration rate of microalgae per time was
the highest.. Based on chapter 2, in the chapter 3, we investigated the effect
of concentrating microalgae using wastewater treatment on DC-MD. The
permeate flux in both conditions was more sharply decreased than chapter
2’same conditions. At 60oC of temperature difference, membrane wetting
occurred. Therefore, it is possible to apply DC-MD to concentrate the
microalgae with wastewater treatment if proper temperature diffence between
feed and permeate solution and cross flow velocity was set, and it is
necessary to membrane cleaning for long maintenance.