Researcher Profile and Settings

Master

Affiliation (Master)

• Faculty of Engineering　Sustainable Resources Engineering　Laboratory of Resources Environment and Remediation

Affiliation (Master)

• Faculty of Engineering　Sustainable Resources Engineering　Laboratory of Resources Environment and Remediation

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Profile and Settings

Affiliation

• Hokkaido University, Faculty of Engineering, Division of sustainable resources engineering, Laboratory of Resources Environment and Remediation, Specially appointed assistant professor, Specially appointed assistant professor

Degree

• PhD (Sustainable Resources Engineering)（Hokkaido University）

Profile and Settings

• Name (Japanese)

  Mufalo

• Name (Kana)

  Walubita

• Name

  202301002683795942

Affiliation

• Hokkaido University, Faculty of Engineering, Division of sustainable resources engineering, Laboratory of Resources Environment and Remediation, Specially appointed assistant professor, Specially appointed assistant professor

Achievement

Research Interests

• Environmental science/geochemistry / Environmental remediation/restoration technology   

Research Experience

• 2023/05 - Today Hokkaido University Faculty of Engineering, Division of Sustainable Engineering

Awards

• 2019/09 Monbukagakusho Scholarship, Japanese Ministry of Education, Culture, Sports, Science and Technology
  
• 2016/10 Rossotrudnichestvo, NUST MISIS, Russian government scholarship
  

Published Papers

• Long-term performance of the adsorption layer system for the recycling and repurposing of arsenic-bearing mudstone as road embankment

  Mitsunori Kajiyoshi, Takahiro Yamamoto, Takahiko Arima, Walubita Mufalo, Ayaka Hashimoto, Takahiro Oumi, Shusaku Yamazaki, Carlito Baltazar Tabelin, Toshifumi Igarashi

  Chemosphere 363 142985 - 142985 0045-6535 2024/09 [Refereed]
  
• Frequency distribution of naturally occurring arsenic leached from excavated rocks of Hokkaido Shinkansen tunnels between Shin-Hakodate-Hokuto and Oshamambe

  Keita Nakajima, Takahiro Yamamoto, Takahiko Arima, Walubita Mufalo, Toshifumi Igarashi

  Soils and Foundations 64 (3) 101445 - 101445 0038-0806 2024/06 [Refereed]
  
• Fluoride leaching from tuff breccia and its removal by natural and commercial adsorbents

  Takahiko Arima, Nohara Yokobori, Walubita Mufalo, Keita Nakajima, Carlito Baltazar Tabelin, Toshifumi Igarashi

  Chemosphere 354 141735 - 141735 0045-6535 2024/04 [Refereed]
  
• Isolation and Characterization of Indigenous Ureolytic Bacteria from Mindanao, Philippines: Prospects for Microbially Induced Carbonate Precipitation (MICP)

  Kryzzyl M. Maulas, Charla S. Paredes, Carlito Baltazar Tabelin, Mark Anthony Jose, Einstine M. Opiso, Takahiko Arima, Ilhwan Park, Walubita Mufalo, Mayumi Ito, Toshifumi Igarashi, Theerayut Phengsaart, Edrhea Villas, Sheila L. Dagondon, Ephrime B. Metillo, Mylene M. Uy, Al James A. Manua, Mylah Villacorte-Tabelin

  Minerals 14 (4) 339 - 339 2024/03/26 [Refereed]
   

  Microbially induced carbonate precipitation (MICP), a widespread phenomenon in nature, is gaining attention as a low-carbon alternative to ordinary Portland cement (OPC) in geotechnical engineering and the construction industry for sustainable development. In the Philippines, however, very few works have been conducted to isolate and identify indigenous, urease-producing (ureolytic) bacteria suitable for MICP. In this study, we isolated seven, ureolytic and potentially useful bacteria for MICP from marine sediments in Iligan City. DNA barcoding using 16s rDNA identified six of them as Pseudomonas stutzeri, Pseudomonas pseudoalcaligenes, Bacillus paralicheniformis, Bacillus altitudinis, Bacillus aryabhattai, and Stutzerimonas stutzeri but the seventh was not identified since it was a bacterial consortium. Bio-cementation assay experiments showed negligible precipitation in the control (without bacteria) at pH 7, 8, and 9. However, precipitates were formed in all seven bacterial isolates, especially between pH 7 and 8 (0.7–4 g). Among the six identified bacterial species, more extensive precipitation (2.3–4 g) and higher final pH were observed in S. stutzeri, and B. aryabhattai, which indicate better urease production and decomposition, higher CO2 generation, and more favorable CaCO3 formation. Characterization of the precipitates by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) and attenuated total reflectance Fourier transform spectroscopy (ATR-FTIR) confirmed the formation of three carbonate minerals: calcite, aragonite, and vaterite. Based on these results, all six identified indigenous, ureolytic bacterial species from Iligan City are suitable for MICP provided that the pH is controlled between 7 and 8. To the best of our knowledge, this is the first report of the urease-producing ability and potential for MICP of P. stutzeri, P. pseudoalcaligenes, S. stutzeri, and B. aryabhattai.
• Effect of chicken manure amendment on lead burden in mice: exposure to lead-spiked soil

  Nyein Chan Soe, Yared Beyene Yohannes, Takamitsu Ohigashi, Hokuto Nakata, Chikae Tatsumi, Yoshitaka Uchida, Walubita Mufalo, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Yoshinori Ikenaka, Mayumi Ishizuka, Shouta M. M. Nakayama

  Journal of Soils and Sediments 1439-0108 2024/03/13 [Refereed]
  
• Insights on hazardous metal bioaccessibility, and groundwater impacted by Zn residues from a legacy mine and risk evaluation of adjacent soils

  Walubita Mufalo, Takahiko Arima, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Shingo Tomiyama, Imasiku Nyambe, Carlito Baltazar Tabelin, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  Environmental Geochemistry and Health 46 (2) 0269-4042 2024/02/06 [Refereed]
  
• 半焼成ドロマイトおよびリン酸塩を用いたカブウェ鉱山鉱さい中の重金属不溶化特性

  Takahiko ARIMA, Kenta NOTO, Walubita MUFALO, Toshifumi IGARASHI, Mayumi ITO, Tsutomu SATO, Hokuto NAKATA, Shouta NAKAYAMA, Mayumi ISHIZUKA

  Resources Processing 70 (3) 141 - 150 1348-6012 2024 [Refereed]
  
• Immobilization of Pb and Zn leached from mining residue materials in Kabwe, Zambia: Performance of calcined dolomite in column experiments

  Walubita Mufalo, Pawit Tangviroon, Takahiko Arima, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Kenta Noto, Takeshi Kawashima, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  Journal of Geochemical Exploration 249 107209 - 107209 0375-6742 2023/06 [Refereed]
  
• Geochemical Characterization of Rock Samples from Selected Fiji Mine Sites to Evaluate On-Site Environmental Vulnerabilities

  Apete Soro, Walubita Mufalo, Takahiko Arima, Carlito Baltazar Tabelin, Toshifumi Igarashi

  Minerals 13 (5) 661 - 661 2075-163X 2023/05/11 [Refereed]
   

  Although mining contributes to about 1.4% of Fiji’s gross domestic product (GDP), the excavated rocks from mining may have detrimental effects on the environment. In this study, rock samples from five Fiji mine sites were selected to assess their geochemical characteristics from an environmental point of view. The mineralogical and chemical constituents, release and retention mechanisms of hazardous elements, and acid/neutralization potential of the rock samples were investigated to understand their environmental impacts on-site. The results showed that sulfide minerals typically found in the rock samples, such as pyrite, chalcopyrite, and sphalerite were responsible for the release of hazardous elements such as Cu, Pb, and Zn via oxidation. Leachates of rock samples from Mt Kasi, Nukudamu, and Wainivesi exceeded the World Health Organization (WHO) regulatory limit for Cu (2 mg/L), Pb (0.01 mg/L), and Zn (3 mg/L) in drinking water. In contrast, no hazardous elements were leached from the Tuvatu and Vatukoula rock samples, which could be attributed to the dissolution of calcite and dolomite that buffered the pH and limited heavy metal mobility. The acid–base accounting (ABA) and accelerated weathering test by hydrogen peroxide indicated that most of the rock samples containing sulfide minerals were likely to generate acidity. Furthermore, the results highlighted that once carbonate minerals are depleted in the rock samples, acid mine drainage (AMD) generation is inevitable. These findings reaffirm the need for committed effort in environmental management of the mine sites to prevent environmental issues associated with AMD.
• Impacts of Surface Water on Windborne Lead Dispersion from the Zinc Plant Leach Residue in Kabwe, Zambia

  Shinsaku Nakamura, Toshifumi Igarashi, Yoshitaka Uchida, Mayumi Ito, Kazuyo Hirose, Tsutomu Sato, Walubita Mufalo, Meki Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  Minerals 2022/04 [Refereed]
  
• Solid-phase partitioning and leaching behavior of pb and zn from playground soils in kabwe, Zambia

  Walubita Mufalo, Pawit Tangviroon, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Meki Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  Toxics 9 (10) 2021/10 [Refereed]
   

  Zambia's Kabwe mine wastes (KMWs) are responsible for contaminating the surrounding soil and dust in the Kabwe district. Unfortunately, these wastes arise from the historical mining activities of lead (Pb) and Zinc (Zn), which lacked adequate waste management strategies. As a result, potentially toxic elements (PTEs) (Pb and Zn) spread across the Kabwe district. To assess the soil pollution derived from previous mining activities, we studied topsoil samples (n = 8) from the school playground soils (SPs). In this study, the degree of contamination, geochemical partitioning, and leachability, coupled with the release and retention of Pb and Zn, were studied. The SPs were classified as extremely enriched (EF > 40) and contaminated with Pb (Igeo > 5). On average, Pb (up to 89%) and Zn (up to 69%) were bound with exchangeable, weak acid-soluble, reducible and oxidizable phases, which are considered as 'geochemically mobile' phases in the environment. The leachates from the soils (n = 5) exceeded the Zambian standard (ZS: 190:2010) for Pb in potable drinking water (Pb < 0.01 mg/L). Furthermore, the spatial distribution of Pb and Zn showed a significant reduction in contents of Pb and Zn with the distance from the mine area.
• Evaluation of Dispersion of Lead-Bearing Mine Wastes in Kabwe District, Zambia

  Shinsaku Nakamura, Toshifumi Igarashi, Yoshitaka Uchida, Mayumi Ito, Kazuyo Hirose, Tsutomu Sato, Walubita Mufalo, Meki Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  Minerals 2021/08 [Refereed]
  
• Immobilization of Lead and Zinc Leached from Mining Residual Materials in Kabwe, Zambia: Possibility of Chemical Immobilization by Dolomite, Calcined Dolomite, and Magnesium Oxide

  Pawit Tangviroon, Kenta Noto, Toshifumi Igarashi, Takeshi Kawashima, Mayumi Ito, Tsutomu Sato, Walubita Mufalo, Meki Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  Minerals 2020/08 [Refereed]
  
• Precipitation behavior of L12 Al3Zr phase in Al-Mg-Zr alloy

  Mikhaylovskaya, A.V., Mochugovskiy, A.G., Levchenko, V.S., Tabachkova, N.Y., Mufalo, W., Portnoy, V.K.

  Materials Characterization 139 2018 [Refereed]
  
• Superplasticity of Al-Mg-Zr alloy

  Mochugovskiy, A., Mikhaylovskaya, A., Mufalo, W., Portnoy, V.

  Defect and Diffusion Forum 385 DDF 2018 [Refereed]
  

Presentations

• Hydrogeochemical characteristics of a tailing facility producing circumneutral seepage waters

  Walubita Mufalo, Kenani, malama, Takahiko Arima, Shingo Tomiyama, Toshifumi Igarashi

  Geo-Environmental Engineering 2024, Kyoto,Japan  2024/05
• Hazardous metal bioaccessibility, and groundwater impacted by Zn Residues in Kabwe, Zambia and hazard evaluation of adjacent soils

  Mufalo Walubita, Takahiko Arima, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  The 9th Joint Seminar on Geo-environmental Engineering and Recycling, Sapporo, Japan  2023/11
• Outline of pilot-scale experiments at the University of Zambia and bio- accessibility of potentially toxic elements from Kabwe mine wastes.

  Mufalo Walubita, Pawit Tangviroon, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Meki, Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  JCC, International Symposium: Mine Impact on One Health. February 2022, Lusaka, Zambia  2022/02
• Invitro bio-accessibility of Pb and Zn from playground soils in Kabwe, Zambia,

  Mufalo Walubita, Pawit Tangviroon, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Meki, Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  9th Zambia Water Forum and Exhibition, June 2021, Lusaka, Zambia.  2021/06
• Oral bioaccessibility of Pb and Zn from playground soils in Kabwe, Zambia,

  Mufalo Walubita, Pawit Tangviroon, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Meki, Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  Proceedings of the 19 th Japan-Korea-France-Canada, Joint Seminar on Geo- Environmental Engineering, Caen, France  2021/05
• Characterization and leaching behavior of playground soils in Kabwe, Zambia

  Mufalo Walubita, Pawit Tangviroon, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Meki, Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  Proceedings of International Symposium on Earth Science and Technology, Fukuoka, Japan  2020/11

Research Projects

• ザンビアにおける鉛汚染のメカニズムの解明と健康・経済リスク評価手法および予防・修復技術の開発

  科学技術振興機構：国際的な科学技術共同研究などの推進 SATREPS

  Date (from‐to) : 2015 -2021 

  Author : 石塚 真由美

   

  汚染除去法を最適化し、健康リスク評価に基づく経済効果を定量化 鉛汚染が深刻なザンビアにおいて生態系および人への汚染メカニズムとリスクを解明し、経済的損失を可視化することで、汚染防御対策や環境修復へと結びつける。リモートセンシングによる調査、地上調査による土壌や植物のキャラクテリゼーション、人の鉛汚染のメカニズム、健康ハザードと経済リスクの可視化、環境修復技術の確立と同時に、モニタリングシステムの構築とキャパシティビルディングによる各専門家の持続的育成を行う。 環境修復、健康・経済リスク評価をもとに、汚染低減に貢献! ザンビアの未来を担う人(特に幼児)の鉛レベルに低下が見られる。ザンビアにおける環境修復、健康リスク評価の新規プロトコルなどの政策に採用される。将来的には、アフリカを中心とした世界的に主要なハザードである金属汚染対策に貢献する。