Abstract
Tea waste (biosorbent) was characterized by BET, SEM, FTIR, XPS, solid state 13C-NMR and applied to remove methylene blue (MB) from aqueous solution. The effect of different factors on MB removal, kinetics, isotherms and potential mechanism was investigated. The results showed that tea waste contains multiple organic functional groups. The optimum solid-to-liquid ratio for MB adsorption was 4.0 g·L−1 and the initial pH of the MB solution did not need to be adjusted to a certain value. The pseudo-second-order model could well fit the adsorption kinetic process. The adsorption process could be divided into two stages: a fast adsorption stage and a slow adsorption stage. The adsorption isotherm could be well described by Langmuir and Temkin isotherm models. The maximum adsorption amount could reach 113.1461 mg·g−1 based on Langmuir isotherm fitting. Desorption and reusability experiments showed that MB adsorption onto tea waste could be stable and could not cause secondary pollution. The interaction mechanism between tea waste and MB involved electrostatic attraction, hydrogen bond, ion exchange, π-π binding. The organic functional groups of tea waste played an important role during the MB removal process. Therefore, tea waste has the potential to act as an adsorbent to remove MB from aqueous solution.
Highlights
Dyeing industry wastewater can pose a significant risk to the eco-environment due to its color depth, high concentration, complex organic components, toxicity and poor bio-degradability characteristics [1]
The organic functional groups of tea waste played an important role during the methylene blue (MB) removal process
When tea waste acted as an adsorbent, its adsorption capacity was not limited by its surface structure and depended on other mechanisms
Summary
Dyeing industry wastewater can pose a significant risk to the eco-environment due to its color depth, high concentration, complex organic components, toxicity and poor bio-degradability characteristics [1]. The treatment of dyeing wastewater is crucial and indispensable. The main approaches for dyeing industry wastewater disposal include chemical degradation, biological treatment, membrane separation, and adsorption [2]. The adsorption technique is currently widely applied to remove pollutants from dyeing wastewater, due to its many advantages, which include easier operation, low cost, and high efficiency [3]. Biomass is an ideal material for adsorbent owing to its wide availability and low cost, especially biomass based on agricultural and forestry residues [4,5,6,7,8,9,10,11,12,13,14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
