Application of waste materials as potential biosorbents for Cu(II) and Zn(II) removal

Abstract

Mining is probably the most common activity that fundamentally impacts the country. The problems connected with the extraction of sulphide ores arise especially during the final stage of mining, closure and abandonment of the extraction area, when the conditions for the generation of strong acid water are most likely to occur. With respect to the diversity of compounds in acid mine drainage (AMD) and its low pH values it is hard to find an effective and inexpensive "active" treatment process. Recently, numerous approaches have been studied for the development of cheaper and more effective technologies, both to decrease the amount of heavy metals and to improve the quality of the treated effluent. Adsorption has become one of the alternative treatments; in the recent years, the search for low-cost adsorbents that have metalbinding capacities has intensified. Adsorption of heavy metals (Cu and Zn) from single-component aqueous solutions onto non-modified poplar sawdust, hemp shives and peat has been studied using the batch-adsorption techniques. For this purpose, solutions with different concentrations ranging from 10 to 150 mg/L have been used. The study was carried out to examine the adsorption capacity of the low-cost waste materials as potential biosorbents for the removal of heavy metals from acid mine drainage. The adsorption isotherms could be better fitted by the Langmuir model (values of the correlation factor range from 0.974 to 0.997). The values of the separation factor (RL) in the present study were found to be within 0.037-0.728, indicating the favorable adsorption process. From the comparison of maximum sorption capacities, it is evident that the best adsorption properties are exhibited by the hemp shives, and copper is overall better adsorbed than zinc (Qmax = 12.84 mg/g and 8.28 mg/g for copper and zinc, respectively). The results indicate that these freely abundant, low-cost waste materials can be treated as economically viable for the removal of metal ions in acidic conditions.

Effect of alkaline treatment of wooden sawdust for the removal of heavy metals from aquatic environments

“…The study of changes adsorption capacity at equilibrium conditions are shown in Tables 5 and 6. These results correspond with previous study [30] that deals with adsorption of Cu(II) and Zn(II) by raw poplar sawdust. It was revealed that the poplar sawdust better correlated to the Langmuir´s model.…”

“…The natural poplar wooden sawdust exhibited a metal ion removal efficiency of approximately 80%. These results correspond with the study Holub et al [30] dealing with adsorption of Cu(II) and Zn(II) from single-component aqueous solutions onto non-modified poplar sawdust (concentrations range from 1 to 150 mg.L -1 ). The authors [9,10,30] also report that low-cost waste materials like wooden sawdust could be used as economically viable for the removal of heavy metal ions in acidic conditions.…”

“…These results correspond with the study Holub et al [30] dealing with adsorption of Cu(II) and Zn(II) from single-component aqueous solutions onto non-modified poplar sawdust (concentrations range from 1 to 150 mg.L -1 ). The authors [9,10,30] also report that low-cost waste materials like wooden sawdust could be used as economically viable for the removal of heavy metal ions in acidic conditions. Due to the low removal capacity of natural non-modified wooden sawdust, it is recommended that this treatment be used for the purification of wastewater with low metal concentrations or post-treatment wastewater.…”

Using the hulls of industrial hemp in urban surface waste water treatment

“…In addition, industrial hemp is used to treat water. It is a component of adsorbents which bond and remove metal ions and bisorbents which capture copper and zinc ions [18][19][20]. Enriched bio-char substrates from hemp pre-treated with hematite, melanterite, and dolomite and subjected to pyrolysis at 400°С have been shown to reduce the concentration of phosphorous in water from 15.5 mg/l to less than 2 mg/l, thereby preventing the epitrophy of water bodies [21].…”

Using of wooden sawdust for copper removal from waters

“…In last two decades is booming for the use of low cost organic materials for heavy metal ions removal. It started with the application of biomass and agricultural waste materials as peat, rice husk, leaves or seeds (Bailey et al 1999;Vieira and (Bailey et al 1999;Demcak et al 2017b) Sawdust 3.9 3.7 -7.3 - (Bailey et al 1999;Holub et al 2016) Volesky 2000; Demcak et al 2017a). The major advantages of adsorption on natural sorbents in comparison to conventional methods include low cost, high efficiency, minimization of chemical or biological sludge, no additional nutrient requirement, regeneration of biosorbents, and possibility of metal recovery (Leng et al 2015).…”