Coal-derived humic acid for application in acid mine drainage (AMD) water treatment and electrochemical devices

Abstract

In this research work, isolation of humic acid from coal of Northeastern region of India is reported. The study is also targeted for application of the coal-derived humic acid in acid mine drainage (AMD) water treatment and electrochemical devices. All the obtained results are compared with the standard humic acid and examined the formation of humic acid from the coal. The isolated coal-derived humic acid is found to be high degree of humifications and relatively stable up to about 200 °C. The FTIR study indicates the formation of metal-humic acid complexes. On treatment with acidic water (AMD), the coal-derived humic acid was found to have the ability to remove toxic metal such as (in order) Pb > Cu > Zn > Cd. In addition, the preliminary electrochemical properties of the isolated humic acid are also discussed in the paper. The specific capacitance of the isolated coal-derived humic acid via cyclic voltammetry and charge-discharge analysis is found to be 7 mF/g at scan rate 10 mV/s and 22 mF/g within the potential window 0.4 V, respectively. The charge-discharge cycles are stable for more than 1000 cycles within the potential window 0.4 V. This study will create a new pathway for the further research in this field.

Environmental evaluation of carbon dot and fullerene formation in atmospheric particulate matter (PM10): observations from their free radical scavenging and electrochemical studies

“…7a, it is observed that the CV curve of the carbon dot solution has an irreversible reduction peak at cathode −0.4 V without an oxidation peak and is also symmetric, revealing the stable capacitive behavior of wsCDs. 25,[44][45][46] The results also showed that the cathodic peaks are similar at the same potential windows with varied scan rates, indicating that the electron transfer kinetics is irreversible. [47][48][49] So, the electrolytes made of wsCDs show irreversible reduction at cathodic potentials due to the absence of the complete redox couple.…”

Extraction and Chemical Characterization of Humic Acid from Nitric Acid Treated Lignite and Bituminous Coal Samples

“…FTIR spectra of humic acid derived from native (raw) coal and HNO 3 treated coal were obtained to determine the structural changes and presence of functional groups in the produced humic acid [27,28].…”

Low-Rank Coal as a Source of Humic Substances for Soil Amendment and Fertility Management

“…Good adsorptive properties of LRC have aroused intense interest for its potential as a versatile environmental adsorbent. The utilization of the coal-based HS in soil remediation [45,[62][63][64] and water treatment systems (municipal wastewater and acid mine drainage) [65][66][67] are recently well-documented. Detoxification studies by research groups led by Qi and by Skłodowski [58,68] have employed LRC as an attractive low-cost adsorbent for the removal of different pollutants from the aquatic and terrestrial environments.…”