which appeared was 3840, which were analyzed. Extraction of data based on countries revealed that the USA leads in publishing papers in this domain, followed by China and Canada, India and Japan.
2 The authors selected papers with significant influence on technologies for selenium removal in the form of published articles, research papers, white papers and review reports on the said domain. The literature comprises material, notions, data, and evidence inscribed from a precise perspective to accomplish confident objectives or express convinced interpretations on the landscape of the technologies to be developed and the way they are to be investigated. The authors further wish to evaluate effectively this literature in the context of the research being proposed.
3 Thereafter, authors began by mapping a number of key strategies for selenium removal from waste and drinking waters. This research suggests mapping of the concepts, opinions, and thoughts from a volume of quality literature. The authors followed a reputable technique for expressing facts and intelligent processes. The mapping presented in this chapter is a description as a “visual outline,” a “pictorial depiction,” and a “topographical allegory” of the research in the domain of water purification. Mapping in this research presents a “perceptible indication” of a researcher's thoughts and clarification of the research domain which can be delivered to both policy makers and scientists.
The present study evaluates the performance of selenium treatment technologies based on several parameters such as, country, city of publication, and Web of Science Core Collection Times Cited Count (which measures the technological impact of literature). The most influential literature is studied for the Multidisciplinary Sciences research. The authorship outline, cooperative catalogue, joint factor, adapted collaborative quantity and research profile. The study also examines international publications output and impact in terms of citations per paper and usage counts in various journals.
This study analyzes the evolution outline of literature related to selenium removal in water and soil in India during 1987–2020 (33 years). The Web of Science is a multidisciplinary international bibliographic archive. The Web of Science international multidisciplinary bibliographical database was used in order to classify the publications reported internationally on the basis of specific scientific field.
1.1.3 Bibliometric Analysis
The Web of Science (WoS) international multidisciplinary bibliographical database used to identify the contributions published worldwide in the field of various technological domains suggested the contribution of various fields of science, as shown in Figure 1.1.
As is evident from Figure 1.1, the research is dominated by the Environmental Sciences, Metrology and Atmospheric Sciences, and the Water Resources domain collectively, which makes up 20% of the total research. This one fifth share of the contribution is followed by Chemistry/Multidisciplinary with 10%, Biotechnology and Applied Microbiology with 10%, and Soil Science with another share of 10% contribution. Adding on these three chunks of domains forms 50% of the total contribution, which is further strengthened by research from: Medicine/Immunology/Pathology; Biochemistry and Molecular Biology/Plant Sciences; Nanoscience and Nanotechnology/Material Science; Ecology/Marine and Fresh Water Biology; Geochemistry and Geophysics; and Agronomy and Plant Sciences.
Figure 1.1 Emerging research field for selenium removal technologies published worldwide.
Figure 1.2 Selenium research publication trends.
The most influential research that spans over the domains is from Chemistry, Multidisciplinary Sciences, Nanoscience and Nanotechnology, and Material Science. Salt et al. (1995), Matoba et al. (2002), Grätzel (2009), and Elmolla and Chaudhuri (2010) have made significant contributions with the following components:
judiciously eradicating problematic contaminants from water discharge
investigating tarn size restrictions
sewage flow management
complying with nitrate, sulfate, chloride discharge constraints
recuperating heavy metal content
freshwater scarcity/confines
groundwater treatment technologies
mine dewatering
acid mine waste water.
Quantitative assessment of the research has been presented in these publications considering year‐wise research outcome, geographical distribution, and type of collaboration, characteristics of highly productive institutions and the method of communication used by the scientists. In a similar manner, the authors explored the second category of domain shown in Figure 1.1 denoted by Biochemistry & Molecular Biology and Plant Sciences (Mandal et al. 2001; Zhu et al. 2009). The representative research outcomes highlight issues related to polluted soils and waters with key environmental and human‐related health issues, which may be moderately resolved by the emergent phytoremediation expertise. In situ phyto‐extraction and phyto‐stabilization have proved to be significantly effective in the removal of toxic metals from the soil (Khan et al. 2020a). This lucrative plant‐based tactic for remediation benefits from the amazing capability of plants to essence rudiments and mixtures from the atmosphere and to metabolize various molecules in their materials. Toxic heavy metals and organic contaminants are the chief goals for phytoremediation. Lately, facts of the biological and molecular apparatuses of phytoremediation commenced to arise collectively with organic and technological approaches intended to heighten and expand phytoremediation. Organic amendments and hydrologic regimes have also been found to be effective for Se removal by using constructed wetlands microcosms (Zhao et al. 2020) Furthermore, numerous arena prosecutions confirm the possibility of ecological cleaning by means of plants. This survey quintessence on the utmost established subsections of phytoremediation expertise and on the biotic apparatuses that brands phytoremediation exertion. Although plants alone show the ability to remove the toxic agricultural pollutants using different strategies, integrated approaches such as microbes and plant associations (rhizoremediation) are also proving to be effective options for metal removal (Khan et al. 2020b).
Figure 1.3 Artificial Intelligence, Machine Learning, and Deep Learning mechanisms in modeling and prediction of water treatment parameters.
The authors' attention was captured by eminent research in the field of Biotechnology and Applied Microbiology (Reeves 1997; Salt et al. 1998; Vara and de Oliveira Freitas 2003; Eapen and D'Souza 2005; Tang et al. 2015). Significantly, active selenium occurs in oxic and anoxic environments, and this presence plays an important role in carbon and nitrogen mineralization by bacteriological anaerobic breathing. Selenium‐breathing bacteria (SeRB) come from a geologically isolated, primeval or filthy world and play a significant role in the selenium process. The chalcogen selenium and its microbial cycle have aroused few concerns, with comparable operational similarity to oxygen and sulfur. Extracellular polymeric substances (EPS), a high‐molecular‐weight biopolymer originated from microbial metabolism, have been found to reduce selenite into non‐soluble and low‐toxicity elemental selenium, which would prevent the sequence of environmental degradation (Zhang et al.