Adsorption of Pb(II) on Spent Leaves of Green and Black Tea

Abstract

Problem statement:In recent years much attention has been focused on the use of biomass residues as low-cost adsorbents for the removal of heavy metal ions from contaminated waters. Spent tea leaves, an abundantly available material that is currently disposed of as a solid waste, are potentially suitable for such applications. Approach: To provide some information on the adsorption properties of tea waste, we evaluated the removal efficiency of lead ions by spent leaves of green and black tea. Batch adsorption experiments were made at 25 and 40°C at initial lead-ion concentrations between 0.01 and 2 g L −1 . Equilibrium data were analyzed by the Langmuir equation to evaluate the maximum adsorption capacity and the equilibrium constant. The adsorption characteristics of the two materials were also compared with those of coffee grounds, activated carbon and Fuller's earth. Results: Experimental data showed that removal efficiencies up to 98-99% can be achieved when using spent tea leaves as lead adsorbent. The results were only marginally affected by the type of tea waste. At low lead loading, the adsorption equilibrium was well described by the Langmuir equation, with a maximum adsorption capacity of 83-130 mg g −1 and an equilibrium constant ranging from 0.112-0.245 L mg −1 . A comparison with other adsorbents provided the following order for lead removal efficiency: Black tea, coffee grounds > green tea > Fuller's earth > activated carbon. Conclusion:The results from this study indicate that using spent tea leaves as an adsorbent may be an efficient and economical means for removing lead and, presumably, other heavy metal ions from aqueous solutions.

Influence of Extraction Conditions on the Recovery of Phenolic Antioxidants From Spent Coffee Grounds

“…As can be seen, the waste contained significant amounts of fiber (17.8%, on a dry weight basis) and protein (10.6%), while fats (4.4%) and sugars (<1%) were comparatively lower. Waxes and ash were in the range of values found for similar plant waste materials (Zuorro and Lavecchia, 2010b).…”

Kinetic study on adsorption of Cr(VI), Ni(II), Cd(II) and Pb(II) ions from aqueous solutions using activated carbon prepared from Cucumis melo peel

“…Adsorption is a simple treatment method for removing metal ions in wastewater, and activated carbon is a powerful adsorbent that is commonly used in industrial wastewater treatment plant (Saleh and Gupta 2011;Saleh and Gupta 2012a, b;Karthikeyan et al 2012;Mittal et al 2009aMittal et al , b, 2010Mittal et al , 2012Wang et al 2006Wang et al , 2009. The growing interest in this material is motivated by its favorable surface properties, uniformity of adsorption, and consequently exceptional adsorption effect (Zuorro and Roberto 2010;Saleh and Gupta 2012b;Saleh and Gupta 2014a, b;Li et al 2016;Devaraj et al 2016). A wide variety of materials have been investigated for this purpose and they can be classified into three categories: (1) natural materials, (2) agricultural wastes, (3) industrial wastes (Saravanan et al 2013a(Saravanan et al , b, c, d, e, f, 2014a(Saravanan et al , b, c, 2015aRajendran et al 2016;Huang et al 2015).…”

Adsorption of penicillin by decaffeinated tea waste

“…Generally, 2 g of DCWT were used with 10 mg/L of PC, and HCl and NaOH were used to adjust pH of the solution. The effects of parameters such as pH (3,7,10), contact time, PC concentration (4, 10, 14 mg/L), DCTW dosage (2, 4, 6, 8, 10 g/250 mL) and temperature (20, 30, 40°C) were studied.…”

“…If biomass is used as the adsorbent (i.e., bioadsorbent), the process is termed as bioadsorption. A desirable adsorbent would be natural, organic and abundant as a waste product from another process 7 . Many bioadsorbents such as bacteria, algae, yeasts, and fungi 8 , chicken feathers 9 , chitosan, and peat 10 are used to remove organic and inorganic contaminants from aqueous solutions.…”