Assessing the effect of leachate of copper slag from the ISASMELT process on cell growth and proximate components in microalgae,Chlorella vulgaris(Beijerinck)

Abstract

Dumping or disposal of huge quantities of slag (containing significant amounts of heavy metals) generated during matte smelting and refining of copper (Cu) is likely to result in environmental toxicity. Detailed chemical studies of Cu-containing slags indicated long-term persistence and poor leachability. Since chemical analyses alone are not sufficient for quantifying biological impact, the effect of copper slag leachate (CSL) on growth and proximate components in marine microalgae, Chlorella vulgaris (Beijerinck), were assessed under laboratory conditions. An inhibitory effect of CSL on cell growth (14.3%) was well below the defined criteria of 50% using algal growth inhibition test. Cellular concentrations of the total protein (TP) in CSL-exposed cultures were significantly higher than the controls. Although the cells of C. vulgaris exposed to CSL accumulated numerically elevated levels of total lipid (TL) compared to control, exposure of C. vulgaris to 100% CSL did not induce stress proteins as evidenced by SDS-PAGE. Further studies assessing the changes in the growth rate and lipid profile might help in complete understanding of the nature of CSL-induced toxicity in microalgae. IntroductionThe generation of waste materials from different mineral industries over the past few decades has increased due to enhanced production of metals from mineral ores associated with industrial development. Generally, the glassy materials left over when metals are pyro-metallurgically extracted from ores which are categorized as waste are termed 'slags'. Limited landfill space with concomitant rise in waste disposal costs prompted the re-use of metal slags. Over the past few years, possibilities of the re-use of metal industry slags (steel slag, fly ash, bottom ash, and blast furnace slag) in various applications such as embankments, roads, pavements, and alternative materials have been explored (Vazquez et al.

Response of Copepods to Elevated pCO2 and Environmental Copper as Co-Stressors – A Multigenerational Study

“…It could be argued that such a situation may have occurred in the Fitzer et al 2012 [16] study wherein the nutritional quality of the microalgae diet would have been de facto downgraded; hence the observed reduction in somatic growth. Conversely, supplementing copper may have upgraded the nutritional status of the diet by increasing protein and lipid titres [76]. Similarly, the possibility remains that the microalgae may have complexed the free copper ions and therefore reduced their toxicity [77].…”

Characterization and pH-dependent leaching behaviour of historical and modern copper slags

“…Additionally, we attempted to answer the question of how these slag materials behave under various pH conditions. Therefore, leaching tests intended to examine leachability of Cu, Zn and Pb as a function of pH (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) were performed in order to establish the potential stability of slags at a given range of conditions.…”

Contribution to the Metal-Slag Equilibrium Study During Carbothermic Reduction of Copper Slag for Cobalt Recovery

“…In recent years, environmental challenges, depletion in high metal grade ores and dumping space availability constraints have prompted researchers to investigate the treatability of mineralogical waste materials for the generation of utilizable products from secondary sources [1,2]. The mining and metallurgical industry have long been the object of criticism for the environmentally destructive nature of their waste materials.…”