MARUO Masahiro




Research Fields, Keywords

Aquatic Chemistry, Analytical Chemistry

Mail Address

E-mail address

Graduating School 【 display / non-display

  • Kyoto University  Faculty of Science  1988.03

Graduate School 【 display / non-display

  • Kyoto University  Graduate School, Division of Natural Science  Doctor's Course  1994.03

Campus Career 【 display / non-display

  • University of Shiga Prefecture  School of Environmental Science  Department of Ecosystem Studies  Professor   2016.04 - Now

  • University of Shiga Prefecture  School of Environmental Science  Department of Ecosystem Studies  Associate Professor   2007.11 - 2016.03

  • University of Shiga Prefecture  School of Environmental Science  Department of Ecosystem Studies  Lecturer   2005.09 - 2007.10

  • University of Shiga Prefecture  School of Environmental Science  Department of Ecosystem Studies  Research Assistant   1995.04 - 2005.08

External Career 【 display / non-display

  • Graduate School of Human and Environmenral Studies, Kyoto University  Special researcher of the Japan Society for the Promotion of Science   1994.04 - 1995.03

  • Department of Earth and Ocean Sciences, Faculty of Science, The University of British Columbia  Visiting Scientist   2003.06 - 2003.11

Academic Society Affiliations 【 display / non-display

  • Japanese Society of Limnology

  • Japanese Society of Analytical Chemistry

  • International Socity of Limnology (SIL)

Field of expertise (Grants-in-aid for Scientific Research classification) 【 display / non-display

  • Geochemistry/Cosmochemistry

  • Meteorology/Physical oceanography/Hydrology

  • Environmental dynamic analysis

  • Analytical chemistry


Papers 【 display / non-display

  • Thermally modified bamboo-eggshell adsorbent for phosphate recovery and its sustainable application as fertilizer

    Sarker Protima, Xin Liu, Naoki Hata, Hiroki Takeshita, Hiroshi Miyamura, Masahiro Maruo

    Elsevier  Environmental Research  231 (Part 1)   115992 -  2023.08

    10.1016/j.envres.2023.115992  Joint Work  Joint(The main charge)


    Phosphate recovery from wastewater using readily available biowaste-based adsorbents is beneficial for both eutrophication control and waste management. Bamboo char has a high-density porous structure and eggshell contains CaCO3 with high affinity for phosphate. The combination of calcined bamboo and eggshell is a potential adsorbent for P recovery that has not been tested previously. Because bamboo char and eggshell both are popular for soil amendment, a P-loaded bamboo and eggshell composite is a promising fertilizer for long-term soil improvement. In this work, the feasibility of calcined bamboo and eggshell (BE) for P recovery and its use as fertilizer were investigated. The adsorption capacity and mechanism were examined using adsorption kinetic, isotherm, and thermodynamic analysis. The kinetic study showed that the experimental data sets were fitted best by a pseudo second-order model, indicating chemisorption. The Langmuir isotherm model estimated maximum adsorption capacities of 95.14 and 98.40 mg/g for BE 1:1 and 2:1 adsorbent. Monolayer adsorption occurred on a homogenous surface. The adsorption reaction was non-spontaneous at 298 K and exothermic for the BE 1:1 and 2:1 adsorbent, and the calculated Langmuir separation factor indicated favorable conditions for P adsorption. The desorption study showed lower P desorption capacity in water than in neutral ammonium citrate. P-loaded eggshell-modified bamboo char was an effective slow-release fertilizer for Japanese mustard spinach cultivation, which is a sustainable and environment friendly use of P-loaded materials.

  • Assessment of Heavy Metals pollution and contamination in Sediment of the Dhaleswari River, Bangladesh

    Abdullah Al Mamun, Protima Sarker, Md. Shiblur Rahaman, Md. Mahbub Kabir, Masahiro Maruo

     International Journal of Environment  10 (1)   1 - 19  2021.07

    10.3126/ije.v10i1.38399  Joint Work  

  • Grain size distribution and chemistry of the brackish Lake sediment in Korea

    I Chan Shin, Tetsuji Akatsuka, Hisayuki Azumi, Lan Ao, Nozomi Amahashi, Maki Oyagi, Noriko Ishida, Naoshige Goto, Masahiro Maruo, Akihiko Yagi, Yashshi Seike, Seung Hyun Lee, Sung Ae Yoon, Jun Kil Choi, Young Woong Byeon, Byung Mo Lee, Osamu Mitamura,Kwang Jin Cho

    Korean Society of Environmental Engineer  Environmental Engineering Research  26 (5)   200365 - *  2020.10

    10.4491/eer.2020.365  Joint Work  Joint(The vice charge)

  • Dual stable isotope characterization of excess methane in oxic water of a mesotrophic lake

    UrumuTsunogai, Yuko Miyoshi, Toshiyuki Matsushita, Daisuke D. Komatsu, Masanori Ito, Chiho Sukigara, Fumiko Nakagawa, Masahiro Maruo

    ASLO  Limnology and Oceanography  65 (2)   2937 - 2952  2020.07

    10.1002/lno.11566  Joint Work  Joint(The vice charge)

  • Differences in dissolved phosphate in shallow-lake waters as determined by spectrophotometry and ion chromatography

    Yi R., Song P., Liu X., Maruo M., Ban S.

    Springer  Limnology  21 (3)   329 - 339  2019.04

    10.1007/s10201-019-00574-2  Joint Work  Joint(The vice charge)


    © 2019, The Japanese Society of Limnology. Phosphorus (P) plays important roles in aquatic ecosystems, but accurately determining phosphorus species (particularly bioavailable phosphate) is difficult. When phosphate concentrations are spectrophotometrically measured as soluble reactive P (SRP), the actual values are often overestimated. Ion chromatography is one method for accurately measuring orthophosphate concentrations. To clarify how the spectrophotometrical measurement overestimates actual phosphate concentrations, we compared estimates of phosphate concentrations in lake waters using both methods. SRP and orthophosphate concentrations in water samples collected from four shallow lakes around Lake Biwa, Japan, were determined monthly for 1 year by spectrophotometry and ion chromatography, respectively. SRP concentrations were frequently higher than those for orthophosphate in all lakes throughout the study period, suggesting that SRP and orthophosphate are not equivalent, although a significant relationship was found between them. Orthophosphate/SRP (ortho/SRP) ratios varied spatiotemporally in all lakes (range 0.11–1.04; mean 0.56), being well predicted by biological-mediated relevant parameters using a stepwise multiple logistic regression analysis (R 2 = 0.76). The results implied that organic matter associated with biological activity contributes to the variability in ortho/SRP ratios. Such large variability in ortho/SRP ratios emphasizes the importance of accurate orthophosphate estimates for understanding P dynamics in aquatic ecosystems.

  • Determination of trace methylphosphonate in natural waters by ion chromatography

    Tsuji K, Maruo M, Obata H

     68 (4)   275 - 278  2019.04

    10.2116/bunsekikagaku.68.275  Joint Work  

  • Determination of dissolved and particulate thiols in Lake Biwa water and extracted fulvic acids by solid phase extraction followed by HPLC with fluorescence detection

    Rasheduzzaman Md., Mai Kawaguchi, Hajime Obata, Masahiro Maruo

    Limnology  Limnology  19 (3)   299 - 309  2018.08

    10.1007/s10201-018-0547-1  Joint Work  


    © 2018, The Japanese Society of Limnology. Thiols are important antioxidants that can modulate the bioavailability and biogeochemistry of many soft metals, although their detection remains challenging in both their reduced (R–S) and oxidized (R–S–S–R) forms. Here, a modified biochemical method was applied to determine the levels of dissolved and particulate thiols in Lake Biwa water and extracted Lake Biwa fulvic acids obtained at various depths. This method involves the use of the reducing agent tris(2-carboxyethyl)phosphine and the fluorescent label 7-fluorobenzofurazan-4-sulfonic acid ammonium salt (SBD-F), followed by solid-phase extraction and HPLC with fluorescence detection. Dissolved cysteine (Cys) (2.0–6.0 nM), glutathione (GSH) (2.8–5.1 nM), and N-acetyl-l-cysteine (NAC) (1.6–4.2 nM) were detected throughout the water column but were broadly consistent at depths of 5–20 m. In contrast, abundant levels of particulate cysteine (1.3–3.5 × 102nM) and glutathione (1.6–3.1 × 102nM) were detected down to depths of 15 m. The particulate cysteine and glutathione were significantly covariant, and the ratios between them reflected the differences in the plankton community composition and availability of these compounds. This work also studied the concentrations of Cys, GSH and NAC in Lake Biwa fulvic acids (LBFAs) for the first time (at 0 m: cysteine, 0.8 nM; glutathione, 1.6 nM; NAC, 2.5 nM; at 10 m: cysteine, 1.4 nM; glutathione, 0.6 nM; NAC, 1.6 nM). The nanomolar to sub-nanomolar concentrations of the particulate and dissolved Cys, GSH and NAC in the lake indicates that these are an important class of ligands for chalcophile metals and may influence the distribution of plankton communities from the epilimnion to the hypolimnion of the lake.

  • Assessment of the Status of Groundwater Arsenic at Singair Upazila, Manikganj Bangladesh; Exploring the Correlation with Other Metals and Ions

    Md. Mostafizur Rahman, Rebeka Sultana, Mashura Shammi, Joti Bikash, Tanveer Ahmed, Masahiro Maruo, Masaaki Kurasaki, M. Khabir Uddin

    Springer  Exposure and Health  8 (2)   217 - 225  2016.02

    10.1007/s12403-016-0196-8  Joint Work  Joint(The vice charge)

  • Trace elements influenced by environmental changes in Lake Biwa: (I) Seasonal variations under suboxic hypolimnion conditions during 2007 and 2009

    Yusuke Nakashima, Akiyoshi Shimizu, Masahiro Maruo, Yoshiki Sohrin

    Springer  Limnology  17 (2)   151 - 162  2016.01

    10.1007/s10201-015-0474-3  Joint Work  Joint(The vice charge)

  • Trace elements influenced by environmental changes in Lake Biwa: (II) Chemical variations in the hypolimnion over the last half-century

    Yoshiki Sohrin, Yusuke Nakashima, Masahiro Maruo

    Springer  Limnology  17 (2)   163 - 173  2016.01

    10.1007/s10201-015-0477-0  Joint Work  Joint(The vice charge)

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Books 【 display / non-display

  • The Geology, Biodiversity and Ecology of Lake Hovsgol (Mongolia)

    C. E. Goulden, T. Sitnikova, J. Gelhaus, B. Boldgiv編:熊谷道夫、占部城太郎、CE Goulden、D Hadbaatar、辻村茂男、速水祐一、関野樹、丸尾雅啓、B. Boldgiv、N. Soninkhshig ほか

    Backhuys Publishers, Leiden, Nederland  526p  2006.02

    Scholarly Book  Joint Work

  • Marine Environment: The Past, Present and Future

    Chen-Tung Arthur Chen編、著者:中山英一郎、丸尾雅啓ほか多数

    Fuwen Press, Kaohsiung, Taiwan  516p  2002.09

    Scholarly Book  Joint Work

Review Papers 【 display / non-display

  • Metal speciation in inland waters

    Masahiro Maruo

    Institute of Oceanochemistry  Transactions of The Institute of Oceanochemistry  28 (1)   2 - 9  2015.04

     Single Work  

  • Chemical analysis of metal complexing ligands in natural waters

    Masahiro Maruo

    Japan Society for Analytical Chemistry  Bunseki  * (470)   71 - 75  2014.02

     Single Work  

  • Editorial: Hydrobiogeochemistry of major Asian rivers

    Tareq S.M., Lu X.X., Shammi M., Maruo M.

    Frontiers in Earth Science  Frontiers in Earth Science  10    2022.11

    10.3389/feart.2022.1065133  Joint Work  

Conferences 【 display / non-display

  • Improvement of thermally activated biochar with calcium from natural source for phosphorus recovery from waste water and its effectiveness as fertilizer

    The 6th International Congress on Water, Waste and Energy Management (WWEM-22)  2022.07

  • 琵琶湖水中の鉄(II)の存在形態に与える溶存有機物の影響

    日本腐植物質学会第37回講演会 テーマ講演「琵琶湖水中における炭素循環プロセス」  2021.11

  • Determination of Trace Methylphosphonate in Freshwater by Ion Chromatography

    SIL 34th International Congress (International Society of Limnology)  2018.08

  • Determination of Dissolved and Particulate Thiols in Lake Biwa Water and Extracted Fulvic Acid by HPLC-Fluorescence Detection with SPE

    3rd SUT-USP Joint Symposium on Environmental Science  2017.12

  • Comparison between soluble reactive phosphorus and orthophosphate concentrations in lake waters

    The 17th International Symposium on River and Lake Environments (ISRLE2014)  2017.03

  • Development of analytical methods for chemical speciation of nutritious elements

    2nd SUT-USP Joint Symposium on Environmental Science  2017.02

  • Determination of nanomolar levels of phosphate in water of P-limited lake in Japan (Lake Biwa) bu ion chromatography

    SIL2016 (33rd SIL Congress)  2016.08

  • Determination of trace orthophosphate in water of Lake Biwa (Japan) by ion chromatography

    25th Goldschmidt 2015  2015.08

  • Characterization of highly strong metal binding ligands in waters of natural lakes in Japan and Korea by electroanalysis

    The 16th International Symposium on River and Lake Environments (ISRLE2014)  2014.08

  • Speciation of Iron(II) in oxic freshwater Lake Biwa, Japan

    SIL XXXII (SIL2013)  2013.08

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