Soil bio-cementation treatment strategies: state-of-the-art review

Bio-cementation is a new sustainable approach that has gained popularity due to its low energy and carbon footprint compared to existing technologies for geotechnical and geoenvironmental engineering applications. Bio-cementation is a soil improvement technique that involves binding the pore space of soil particles with calcium carbonate minerals by microbially induced carbonate precipitation (MICP) and filling the soil pore space. The purpose of this article is to present a current state-of-the-art and comprehensive discussion on the development of bio-cementation for soil improvement/reinforcement. Premixing, injection, immersing, and surface percolation are identified as four distinct bio-cementation treatment techniques. Furthermore, scholars have reported employing ureolytic bacteria such as Sporosarcina pasteurii, Bacillus sphaericus, and Lysinibacillus sphaericus) isolated from corals, limestone caves, soils, waste materials, seawaters, and other sources to accomplish effective bio-cementation Some of the major issues (bacterial cultivation costs and ammonium production) that impede its industrial potential and promising remedial techniques were also discussed. This state-of-the-art review also discussed the benefits and drawbacks of bio-cementation compared to traditional approaches. The significance of enzyme-induced carbonate precipitation as a soil bio-cementation alternative to MICP was also highlighted. Finally, the sustainable procedure, bio-cementation principles, and future implications are discussed

Highway infrastructure and building information modelling in UK

Traditional methods of design are becoming less relevant and prevalent, due to institutionalising of Building Information Modelling (BIM) within statutory regulations and the huge amount of data that BIM presents to practice; especially in 3D models. This can be seen in the A1 Dishforth-to-Barton road infrastructure improvement scheme which comprises the A1 Dishforth-to-Leeming and A1 Leeming-to-Barton schemes. The traditional method of design was central to the A1 Dishforth-to-Leeming scheme and BIM central to the A1 Leeming-to-Barton scheme. So this report presents a comparative study of the traditional and BIM methods in relation to the A1 Dishforth-to-Barton improvement scheme through the perception of key professionals involved in this project. A qualitative research study was conducted through the use of an open-ended questionnaire intended to bridge gaps in perceptions and understanding of both methods. Judgemental sampling technique was used to select experienced respondents who understand and participated in the A1 Dishforth-to-Barton road infrastructure improvement scheme. The study reveals an incontrovertible complementary nature of both methods and that the realisation of the 2016 mandate appears doubtful due to lack of standardization, training and level of awareness. It is highly recommended that a statutory incentivization framework for BIM be conceptualised and considered for implementation to attract and encourage small scale participants. Of high priority is the subsidization of in-house training by local authorities and localized joint ventures by smaller companies for specialist training

Calcium carbonate bioprecipitation mediated by ureolytic bacteria grown in pelletized organic manure medium

New sustainable methods utilizing biological processes to mediate the improvement of soil properties have recently emerged. Microbially induced calcite precipitation (MICP) has been demonstrated as a potential sustainable technique for soil improvement and solidification, erosion control and prevention, and remediation of contaminants. This paper describes experiments conducted to demonstrate the efficacy of using pelletized organic manure (POM), supplemented with varying concentrations of yeast extract (20 to 80%, w/v) as a suitable alternative low-cost nutrient source for bacteria cultivation during the MICP soil biocementation process. The evaluation entails using scanning electron microscopy with electron-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis analysis for cementation efficiency, relative merits of the mechanisms, and biocementation byproduct. The results demonstrated that ureolytic bacteria can be cultivated with POM containing yeast extract (4 to 8 g/L), and this alternative bacteria cultivation nutrient source produced more crystal formations with less visible pore spaces in biocemented soil. This study reveals that more treatment cycle (bacterial cultures and chemical solution) approaches would be required during biocementation to achieve successful crystal shapes to bridge soil particles when using ureolytic bacteria grown in the inexpensive medium supplemented with low yeast extract

The global research trend on microbially induced carbonate precipitation during 2001–2021: a bibliometric review

Microbially induced carbonate precipitation (MICP) is a remarkable method that creates sustainable cementitious binding material for use in geotechnical/structural engineering and environmental engineering. This is due to the increasing demand for alternative environmentally friendly technologies and materials that result in minimal or zero carbon footprint. In contrast to the previously published literature, through bibliometric analysis, this review paper focuses on the current prospects and future research trends of MICP technology via the Scopus database and VOSviewer analysis. The objective of the study was to determine the annual publications and citations trend, most contributing countries, the leading journals, prolific authors, productive institutions, funding sponsors, trending author keywords, and research directions of MICP. There were a total of 1058 articles published from 2001 to 2021 on MICP. The result demonstrated that the volume of publications is increasing. China, Construction and Building Materials, Satoru Kawasaki, Nanyang Technological University, and the National Natural Science Foundation of China are the leading country, journal, author, institution, and funding sponsor in terms of total publications. Through the co-occurrence analysis of the author keywords, MICP was revealed to be the most frequently used author keyword with 121 occurrences, a total link strength of 213, and 152 links to other author keywords. Furthermore, co-occurrence analysis of text data revealed that researchers are concentrating on four important research areas: precipitation, MICP, compressive strength, and biomineralization. This review can provide information to researchers that can lead to novel ideas and research collaboration or engagement on MICP technology

Bibliometric analysis of research trends in biogranulation technology for wastewater treatment

Inadequate management and treatment of wastewater pose significant threats, including environmental pollution, degradation of water quality, depletion of global water resources, and detrimental effects on human well-being. Biogranulation technology has gained increasing traction for treating both domestic and industrial wastewater, garnering interest from researchers and industrial stakeholders alike. However, the literature lacks comprehensive bibliometric analyses that examine and illuminate research hotspots and trends in this field. This study aims to elucidate the global research trajectory of scientific output in biogranulation technology from 1992 to 2022. Utilizing data from the Scopus database, we conducted an extensive analysis, employing VOSviewer and the R-studio package to visualize and map connections and collaborations among authors, countries, and keywords. Our analysis revealed a total of 1703 journal articles published in English. Notably, China emerged as the leading country, Jin Rencun as the foremost author, Bioresource Technology as the dominant journal, and Environmental Science as the prominent subject area, with the Harbin Institute of Technology leading in institutional contributions. The most prominent author keyword identified through VOSviewer analysis was “aerobic granular sludge,” with “sequencing batch reactor” emerging as the dominant research term. Furthermore, our examination using R Studio highlighted “wastewater treatment” and “sewage” as notable research terms within the field. These findings underscore a diverse research landscape encompassing fundamental aspects of granule formation, reactor design, and practical applications. This study offers valuable insights into biogranulation potential for efficient wastewater treatment and environmental remediation, contributing to a sustainable and cleaner future

Two decades of research trends in microbial-induced carbonate precipitation for heavy metal removal: a bibliometric review and literature review

Amidst the increasing significance of innovative solutions for bioremediation of heavy metal removal, this paper offers a thorough bibliometric analysis of microbial-induced carbonate precipitation (MICP) for heavy metal removal, as a promising technology to tackle this urgent environmental issue. This study focused on articles published from 1999 to 2022 in the Scopus database. It assesses trends, participation, and key players within the MICP for heavy metal sequestration. Among the 930 identified articles, 74 countries participated in the field, with China being the most productive. Varenyam Achal, the Chinese Academy of Sciences, and Chemosphere are leaders in the research landscape. Using VOSviewer and R-Studio, keyword hotspots like "MICP", "urease", and "heavy metals" underscore the interdisciplinary nature of MICP research and its focus on addressing a wide array of environmental and soil-related challenges. VOSviewer emphasises essential terms like "calcium carbonate crystal", while R-Studio highlights ongoing themes such as "soil" and "organic" aspects. These analyses further showcase the interdisciplinary nature of MICP research, addressing a wide range of environmental challenges and indicating evolving trends in the field. This review also discusses the literature concerning the potential of MICP to immobilise contaminants, the evolution of the research outcome in the last two decades, MICP treatment techniques for heavy metal removal, and critical challenges when scaling from laboratory to field. Readers will find this analysis beneficial in gaining valuable insights into the evolving field and providing a solid foundation for future research and practical implementation