**4. Conclusion**

In the present study, we observed the aquatic ecosystem and investigated the water quality of anthropogenically eutrophied pond between 2006 and 2009. As a result, it was found that in this pond, it was easy for blue-green algae to grow intensively, and it was easy for the pH of the surface water to rise by photosynthesis of the blue-green algae (pH 9.2 ± 0.32, *n* = 24, in 2008). By utilizing these features, we considered to develop a simultaneous recovery system of phosphate ion and blue-green algae using calcium chloride. As the pre-examinations using a growth medium, we observed the phenomenon that the precipitation of calcium phosphate and the coagulation of *M. aeruginosa* occurred simultaneously. The growth medium of 100 mL was filtrated using a prototype sand filtration column which was fabricated to be symmetric for reverse cleaning and to simultaneously recover both phosphate ion and blue-green algae. As a

**33**

**Author details**

Hideaki Nakamura

Department of Liberal Arts, Tokyo University of Technology, Tokyo, Japan

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: nakamurahd@stf.teu.ac.jp

*Water Chemical Remediation for Simultaneous Removal of Phosphate Ion and Blue-Green Algae…*

result, from the growth medium, phosphate ion and *M. aeruginosa* could remove 97.4 and 99.6%, respectively. Based on the results, we next constructed a simultaneous phosphate ion and blue-green algae removal system which consisted of a calcium chloride injector and a sand filtration column. Using the sand filtration column of this system, pond water of 7 L was treated, and phosphate ion of 53% and *M. aeruginosa* of 85% were removed, respectively. Our results obtained in the present study were very primitive comparing with the preexamination results using the prototype sand filtration column. However, we believe that our WCR system can be improved to recover both phosphate ion and blue-green algae simultaneously as biomass resources by subsequent

The author acknowledges Messrs. Mayu Taguchi, Takuto Toshioka, and Tohru Sasaki for the contributions to their experiments in aquatic ecosystem and the present removal system. The author also appreciates Messrs. Naoya Yasue, Tomoyuki Sakamaki, Norio Suka, Jun Kanno, Yuki Ito, Kohei Taguchi, Kyota Suzuki, Daisuke Tokunaga, and other lab members for their contributions and assistances with the experiments in water monitoring. The present work was financially supported in part by grants of collaborative projects in the Tokyo University of Technology.

*DOI: http://dx.doi.org/10.5772/intechopen.88490*

**Acknowledgements**

**Conflict of interest**

**Abbreviations**

CO3

HCO3

studies and applied to remediate hypertrophic water body.

The author states that there is not conflict of interest.

CO2 dissolved carbon dioxide

COD chemical oxygen demand

WCR water chemical remediation

provided the original work is properly cited.

<sup>2</sup><sup>−</sup> carbonate ion

DO dissolved oxygen

<sup>−</sup> bicarbonate ion *M. aeruginosa Microcystis aeruginosa* TOC total organic carbon

*Water Chemical Remediation for Simultaneous Removal of Phosphate Ion and Blue-Green Algae… DOI: http://dx.doi.org/10.5772/intechopen.88490*

result, from the growth medium, phosphate ion and *M. aeruginosa* could remove 97.4 and 99.6%, respectively. Based on the results, we next constructed a simultaneous phosphate ion and blue-green algae removal system which consisted of a calcium chloride injector and a sand filtration column. Using the sand filtration column of this system, pond water of 7 L was treated, and phosphate ion of 53% and *M. aeruginosa* of 85% were removed, respectively. Our results obtained in the present study were very primitive comparing with the preexamination results using the prototype sand filtration column. However, we believe that our WCR system can be improved to recover both phosphate ion and blue-green algae simultaneously as biomass resources by subsequent studies and applied to remediate hypertrophic water body.
