Removal of Humic Acid in Water Using Novel Nanomaterials

Abstract

The present study investigates the effectiveness of the photocatalytic degradation of humic acid (HA) in aqueous suspensions. Initial batch scale experiments and tests performed using the Continuous Flow Photoreactor have enabled the close inspection of the performance of the photocatalysts nano TiO2, and nano ZnO dispersions. These photocatalysts were used in aqueous dispersions employing medium-pressure mercury-vapour lamps emitting UV-A (λ = 400 nm) and UV-C (λ = 250 nm). Moreover, glass microfibre filters were embedded and coated with Laponite RD (synthetic polycrystalline swelling clay) in order to produce catalytic films to be used in small scale experiments to remove HA through filtration. The findings of this study shows that the HA adsorb highly onto the ZnO and TiO2 surface thus initiating photodegradation, the effectiveness of which steadily increases with irradiation time along with an increase in the biodegradability of HA.

Activation of Humic Acid in Lignite Using Molybdate-Phosphorus Hierarchical Hollow Nanosphere Catalyst Oxidation: Molecular Characterization and Rice Seed Germination-Promoting Performances

“…Humic acid from activated lignite contained more S-containing organic molecules that were dominant, which may be due to the presence of proteins and amino sugar. The solid-state 13 C NMR of humic acid from AML and RL were obtained to further analyze the structure (Figure S4a). According to a previous study, each 13 C NMR spectrum of the humic acid extracted from lignite generally includes three major peaks: aliphatic carbons (0−110 ppm), aromatic carbons (110−160 ppm), and carboxyl carbons (160−220 ppm).…”

“…The solid-state 13 C NMR of humic acid from AML and RL were obtained to further analyze the structure (Figure S4a). According to a previous study, each 13 C NMR spectrum of the humic acid extracted from lignite generally includes three major peaks: aliphatic carbons (0−110 ppm), aromatic carbons (110−160 ppm), and carboxyl carbons (160−220 ppm). 51 The differences between original RL and pretreated AML were slight but still enough to show the effects introduced by the Mo-P-HH catalyst.…”

“…The molecular characterization of humic acid was performed by negative ion electrospray ionization (ESI) FT-ICR MS analysis (Bruker, Billerica, MA, U.S.A.). 13 C Solid-state NMR spectra was obtained using a Bruker AV-300 (Germany) spectrometer. The molecular size measurement of the sample was made by high-pressure size exclusion chromatography (HPSEC, G1315B, Agilent Technologies).…”

“…Huang et al investigated Pd/Fe 3 O 4 as a catalyst in a H 2 O 2 solution to degrade humic acid . Kim et al applied nano-TiO 2 and nano-ZnO to photocatalytically oxidize humic acid in aqueous solutions . Although most catalysts can be used to oxidize lignite to increase the humic acid yield from lignite, their actual applications are limited because of their high toxicity, low abundance, and poor durability. − Recently, it has been found that a Pd/CeO 2 catalyst has excellent performance in increasing the humic acid content in lignite by a solid-ball mill technology .…”

Multifunctional Iron–Humic Acid Fertilizer from Ball Milling Double-Shelled Fe–N-doped Hollow Mesoporous Carbon Microspheres with Lignite

“…Hence, activating HA to increase its water solubility can improve its positive effect to crops. In past decades, many nanocatalysts such as nanosized TiO 2 , Pd/Ce 2 , and Zr–iron have been used for the oxidation of HA in lignite to improve its water solubility. − However, their large-scale production and industrial applications are limited due to their potential toxicity and low efficiency. , In order to improve the oxidation efficiency of HA and ensure its safe application in agriculture, it is necessary to develop a nontoxic, environmentally friendly, and highly efficient catalyst. Compared with traditional activation methods, solid-phase activation technology using a nanocatalyst is an environmentally friendly and effective method that can produce water-soluble HA from lignite .…”