Removal of benzene, MTBE and toluene from contaminated waters using biochar-based liquid activated carbon

Abstract

Fuel components such as benzene, toluene, and methyl tertiary-butyl ether (MTBE) are frequently detected pollutants in groundwater resources. Ex-situ remediation technologies by activated carbon have been used for treatment for many years. However, due to high cost of these technology, more attention has been given to the in-situ remediation methods of contaminated groundwaters using liquid carbon adsorbents. Literature search showed limited studies on using adsorbents in liquid form for the removal of such contaminants. Therefore, this lab-scale study investigates the capacity of using raw biochar-based liquid activated carbon and iron-modified biochar-based liquid activated carbon to remove these pollutants. The adsorption efficiency of the synthesized liquid activated carbon and iron-modified liquid activated carbon mixed with sand, limestone, and 1:1 mixture of sand/limestone, was tested using batch suspension experiments. Adsorption by granular activated carbon was also investigated for comparison with liquid activated carbon. Results of the study revealed that mixing of liquid activated carbon or LAC-Fe on subsurface materials had not improved the removal efficiency of MTBE. At the same time, it showed a slight improvement in the adsorption efficiency of benzene and toluene. In all cases, the removal by GAC was higher with around 80% and 90% for MTBE and BT, respectively. Results also showed that benzene and toluene were better removed by liquid activated carbon and iron-modified liquid activated carbon (∼ 40%) than MTBE (∼ 20%). It is also found that water chemistry (i.e., salinity and pH) had insignificant effects on the removal efficiency of pollutants under the study conditions. It can be concluded that more research is needed to improve the capacity of biochar-based liquid-activated carbon in removing MTBE, benzene and toluene compounds that will lead to improve the utilization of liquid activated carbon for the in-situ remediation of contaminated groundwaters.

Adsorptive Removal of Volatile Organic Compounds from Industrial Effluent Using Synthesized ZnO-CA Composite Base Adsorbent

“…metal oxides can increase the effectiveness of technologies and reduce the cost of water treatment due to their small size and high absorption efficiency (3). Therefore, in this study, the adsorption studies of toluene and benzene (8,9,10), two prominent volatile organic compounds, were performed using a composite of zinc oxide and cellulose acetate nanocomposites (11). The nanocomposites were fully characterized to ascertain their structural and morphological properties.…”

“…The nanocomposites were fully characterized to ascertain their structural and morphological properties. Additionally, the adsorption process was optimized by studying factors such as adsorbent dose, initial concentration, solution pH affecting adsorption processes, etc (8).…”

“…This study aimed to synthesize a composite material using zinc oxide and cellulose acetate derived from agricultural waste and evaluate its adsorption properties/efficiency for the effective removal of benzene and toluene from wastewater. Benzene and toluene, amongst others, are volatile organic compounds commonly found in petroleum-based products, fuels, solvents, and various industrial processes and are considered pollutants and can be harmful to human health and the environment, even at low concentrations (8,9).…”

A Study on the Gaseous Benzene Removal Based on Adsorption onto the Cost-Effective and Environmentally Friendly Adsorbent

“…However, various adsorbents and technologies are available to treat gaseous benzene. Their performance has been investigated for its low energy consumption, ease of operation, and high removal efficiency [19][20][21]. Today, varieties of activated carbons with different physicochemical properties are selected according to benzene concentration and amount, as well as its duration in the indoor air.…”

Multi-functionalization of woody biochar tuned for sustainable surface microbiological processes: a case study for energy applications

“…Recently, numerous strategic methodologies, including optimisation of pyrolysis conditions and temperature, activating agents, and pH, have been developed to tailor the physico-chemical properties of biochar. 15 Due to these tuneable properties, biochar finds diverse applications in many fields, including soil remediation, 16 carbon storage, 17 manure composting, 18 decontamination of water and waste water 19,20 by means of micro and macro filters, 21 biogas production, 22 detoxificants, 23 in the building sector, 24 air pollution management, 25 in textiles as a fabric addictive and flame-retardant clothing, 26 catalysts, 27 activators, 1 electrode materials, and modifiers. 28 It has also been reported that the stable porous matrix of the biochar acts as a good microenvironment for microorganisms.…”