Toxicity of raw and neutralized bauxite refinery residue liquors to the freshwater cladoceran Ceriodaphnia dubia and the marine amphipod Paracalliope australis

Abstract

The extraction of alumina from bauxite produces a highly toxic residue, termed bauxite refinery residue (BRR) or red mud. The toxicity of this material is due to chemical and biological effects of high pH, alkalinity, electrical conductivity (EC), and Na(+) and Al(3+) concentrations. Several neutralization techniques may allow BRR to be used for environmental remediation. The present study investigated standardized 48-h acute toxicity tests with a freshwater cladoceran, Ceriodaphnia dubia, and a marine amphipod, Paracalliope australis, against raw supernatant BRR liquor (RL) versus liquors neutralized with acid (ANL), CO(2) (CNL), seawater (SNL), and a hybrid method (HNL). Based on 48-h LC50 values, the toxicity of the liquors to C. dubia increased in the following order; HNL ≤ SNL< ANL ≤ CNL < RL, with comparable responses from P. australis. The high toxicity of RL likely is due to high pH (≈ 12), alkalinity, and Al concentration. Toxicity of CNL likely is due to high EC and alkalinity. Sulfate and Na(+) concentrations are considered sources of toxicity in ANL. Seawater-neutralized liquor and HNL were considerably less toxic to both test species. These data provide evidence of the acute lethal toxicity of raw supernatant liquor from BRR and four neutralized supernatant liquors to the freshwater cladoceran C. dubia and the marine amphipod P. australis, providing valuable baselines for further ecotoxicological investigations of BRR materials in aquatic environments.

Comparison of several different neutralisations to a bauxite refinery residue: Potential effectiveness environmental ameliorants

“…We have published previously on the effect that these different neutralisation techniques have on alkalinity solubility, supernatant liquor geochemistry, and toxicology (Howe et al, 2011;Johnston et al, 2010), however no comparison on the effectiveness of these neutralised solids for reuse or as environmental ameliorant has been made. Consequently, neutralisations techniques that do not adequately deal with the toxic components of the residue (e.g., the soluble alkalinity) such as simple residue washing, lead to toxicity issues (e.g., acid neutralisation, Burke et al, 2013;Renforth et al, 2012) in the waste waters (Howe et al, 2011), nor widely used or considered by industry currently (e.g., gypsum neutralisation, Renforth et al, 2012;Summers et al, 1993;Wong and Ho, 1993) are not considered in this work. Therefore, this paper compares an un-neutralised red mud (UNRM), and the derivatives of this red mud, Basecon™, CO 2 -neutralised red mud (CNRM), and CO 2 -Basecon™-neutralised red mud (Hybrid), and how these changes affect potential environmental applications.…”

“…Moreover, geochemistry of BRR is such that it is listed as a contaminated waste under the Basel Convention (BasalConvention., 1992), limiting its transportation for storage, disposal or treatment applications, and re-use options (Hanahan et al, 2004;Hind et al, 1999;Howe et al, 2011;Klauber et al, 2011;McConchie et al, 2005;Paramguru et al, 2005;Power et al, 2011;Zhang et al, 2001).…”

“…The sheer size of the alumina industry is such that global production estimates for BRR are some 120 million tonnes/ year, with a 2007 global inventory of %2.7 billion tonnes ; between 1.1 and 6.2 tons are produced per tonne of alumina . Because of the high caustic content and sodicity, a wide range of trace metal contaminants, high pH (>13), and alkalinity (%30,000 mg/L as equivalent CaCO 3 ), BRR represents a major ecological and economic problem worldwide (Hanahan et al, 2004;Hind et al, 1999;Howe et al, 2011;McConchie et al, 2005;Zhang et al, 2001).…”

Effect of Synergistic Aging on Bauxite Residue Dust Reduction Performance via the Application of Colloids, an Orthogonal Design-Based Study

“…By the end of 2019, Chinese annual production and gross inventory of bauxite residue have already reached to 60 Mt and 400 Mt, respectively, which accounted for over 20% of global output. Bauxite residue consists of 60% red sand fraction (>150 μm) and 40% red mud fraction (<150 μm) [ 3 ]. As bauxite residue is highly alkaline, saline and contains a certain amount of heavy metal particles and radioactive components [ 4 ], the direct discharge of bauxite residue is strongly prohibited for its detrimental occupational and environmental impacts [ 5 , 6 , 7 ], such as asthma, rhinitis, eye irritation, water pH alteration [ 8 ], soil salinity and genotoxicity [ 9 , 10 ].…”

From green to transparent waters : Managing eutrophication and cyanobacterial blooms by geo-engineering

“…However, adding solidphase compounds such as RS Br to the water will cause turbidity and lead to elevated suspended solid concentrations in the water, which might have side effects on biota (Bilotta and Brazier, 2008). Unlike the common high-pH waste product-red mudfrom bauxite refineries involved in aluminum production (Howe et al, 2011), raw bauxite might be less detrimental, yet applying bauxite will also increase the concentrations of suspended solid. The elevated Cr concentration in BAU 1 Gr is not expected to cause toxicity since after application the SPS will be diluted in the sediment.…”