Chromium removal from chrome-tannery effluent after alkaline precipitation by adsorption using municipal solid waste-derived activated biochar

Issue Date

5-2020

Abstract

Municipal solid wastes (MSW) accumulation and generation of toxic wastewater are common issues especially in highly industrialized and urban communities. To address these concerns, municipal solid wastes was converted to activated biochar (MSWAB), which can be used to treat alkaline-precipitated tannery wastewater by adsorption to meet the environmental limit of 0.5 ppm Crtotal concentration. Alkali precipitated tannery wastewater has an initial Crtotal concentration of about 3364.37. MSW pyrolysis at 500°C for 30 mins produced about 50.42 % w/w biochar, which was activated using KOH to improve its adsorption capacity. Equilibrium time for Cr adsorption using MSWAB was established after 1 hour of adsorption. The effect of pH and adsorbent dosage on the Crtotal removal were then tested from pH 6.5 to 12 and from 0.2 to 10 mg MSWAB/mL wastewater, respectively, using 2k factorial design. Statistical results show that both factors were significant on the percent removal of Crtotal. Maximum Crtotal removal obtained was about 98.97% using MSWAB as adsorbent at pH 12 with 10 mg/mL dosage. Freundlich isotherm best described the adsorption of Cr onto MSWAB (R2 = 0.8231) as compared to the Langmuir isotherm (R2 = 0.5079). Commercial activated carbon (CAC) with a removal of 57.39 % was still observed to have higher removal efficiency compared to the 55 % removal using MSWAB at pH 8.5. However, considering the low cost of feedstock used, environmental benefits, and its adsorption performance, MSWAB can be a possible alternative for CAC.

Source or Periodical Title

IOP Conference Series: Materials Science and Engineering

ISSN

1757-8981

Volume

778

Issue

1

Page

1-12

Document Type

Article

Physical Description

illustrations; graphs; table; references

Language

English

Identifier

10.1088/1757-899X/778/1/012134.

Digital Copy

yes

Link to Full Text

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