Shengguo Xue

Bio: Shengguo Xue is an academic researcher from Central South University. The author has contributed to research in topics: Bauxite & Environmental chemistry. The author has an hindex of 29, co-authored 90 publications receiving 2347 citations.

A review of the characterization and revegetation of bauxite residues (Red mud)

Abstract: Bauxite residue (Red mud) is produced in alumina plants by the Bayer process in which Al-containing minerals are dissolved in hot NaOH The global residue inventory reached an estimated 35 billion tons in 2014, increasing by approximately 120 million tons per annum The appropriate management of bauxite residue is becoming a global environmental concern following increased awareness of the need for environmental protection Establishment of a vegetation cover is the most promising way forward for the management of bauxite residue, although its physical and chemical properties can limit plant growth due to high alkalinity and salinity, low hydraulic conductivity, trace element toxicity (Al and Fe), and deficiencies in organic matter and nutrition concentrations This paper discusses the various revegetation and rehabilitation strategies Studies of the rehabilitation of bauxite residues have mainly focused on two approaches, amelioration of the surface layer and screening of tolerant plants and soil microorganisms Amendment with gypsum can reduce the high alkalinity and salinity, promote soil aggregation, and increase the hydraulic conductivity of bauxite residues Organic matter can provide a source of plant nutrients, form stable complexes with metal cations, promote hydraulic conductivity, stabilize soil structure, and provide an energy source for soil organisms Tolerant plants and microorganisms such as halophytes and alkaliphilic microbes show the greatest potential to ameliorate bauxite residues However, during restoration or as a result of natural vegetation establishment, soil formation becomes a critical issue and an improved understanding of the various pedogenic processes are required, and future direction should focus on this area

Proposal for management and alkalinity transformation of bauxite residue in China

Abstract: Bauxite residue is a hazardous solid waste produced during the production of alumina. Its high alkalinity is a potential threat to the environment which may disrupt the surrounding ecological balance of its disposal areas. China is one of the major global producers of alumina and bauxite residue, but differences in alkalinity and associated chemistry exist between residues from China and those from other countries. A detailed understanding of the chemistry of bauxite residue remains the key to improving its management, both in terms of minimizing environmental impacts and reducing its alkaline properties. The nature of bauxite residue and the chemistry required for its transformation are still poorly understood. This review focuses on various transformation processes generated from the Bayer process, sintering process, and combined Bayer-sintering process in China. Problems associated with transformation mechanisms, technical methods, and relative merits of these technologies are reviewed, while current knowledge gaps and research priorities are recommended. Future research should focus on transformation chemistry and its associated mechanisms and for the development of a clear and economic process to reduce alkalinity and soda in bauxite residue.

Heavy metal water pollution: A fresh look about hazards, novel and conventional remediation methods

Abstract: Water pollution is one of the global challenges that society must address in the 21st century aiming to improve water quality and reduce human and ecosystem health impacts. Industrialization, climate change, and expansion of urban areas produce a variety of water pollutants. In this work, we discuss some of the most recent and relevant findings related to the release of heavy metals, the possible risks for the environment and human health, the materials and technologies available for their removal. Anthropogenic activities are identified as the main source of the increasing amounts of heavy metals found in aquatic environments. Some of the health hazards derived from repeated exposure to traces of heavy metals, including lead, cadmium, mercury, and arsenic, are outlined. We also give some perspectives about several techniques used to detect heavy metals, as well as about the factors that could affect the contaminant removal. The advantages and drawbacks of conventional and non-conventional heavy metal removal methods are critically discussed, given particular attention to those related to adsorption, nanostructured materials and plant-mediated remediation. Some of the commercial products currently used to eliminate heavy metals from water are also listed. Finally, we point out some the requirements and opportunities linked to developing efficient methods for heavy metal removal, such as the ones that exploit nanotechnologies.