Nanoparticle-loaded multifunctional natural seed gel-bits for efficient water purification

Abstract

In this work we demonstrate the use of natural seed based hydrogel bits as robust, recoverable and recyclable support for nanoparticulate catalytic media for multipurpose water purification application. We show that the inexpensive and easily available natural seeds sabja (Ocimum basilicum), which can absorb water to about 30 times their weight can be easily loaded with nanoparticles of functional metal oxides such as visible light photo-catalyst N-doped TiO 2 or magnetite (Fe 3 O 4 ) for effective multiple water purification objectives such as efficient photocatalytic degradation of toxins or bacteria, heavy metal ion (As 3+ , Cr 6+ , Pb 2+ , Cd 2+ ) removal or simple particulate filtering. Indeed, innovative nanoparticle loading strategy can be used to load organic and inorganic materials concurrently, sequentially or simultaneously on the gel-bits while they swell in the process of water absorption. Interestingly the gel-bits maintain their individual identity without agglomeration or fusing, and given their swollen size of about few millimetres they can be easily separated out by simple cloth or millimetre scale filtering. This alleviates the difficulties associated with separating nanoparticles dispersed in the media directly for photocatalytic or other purification purposes. With magnetic nanoparticle co-loading they can also be separated out by magnetic field, which can be beneficial in situations wherein filtering may not be an easy option. It is useful to mention that the same seed gel-bits can also serve as particle size filters for specific applications.

Chromium removal from contaminated waters using nanomaterials – A review

“…Among the various materials used for chromium removal, nanoparticles have been the most common, either using just the core nanoparticles [9,[40][41][42][43][44][45][46], nanoparticles with functionalization [35,[47][48][49], or modified nanoparticles incorporated on substrates [36,50]. Other type of materials have been used, such as nanocomposites [37,51,52], nanofibers [38] and carbon nanotubes [39].…”

“…The maximum allowed concentration of total chromium in residual waters is 2 000 µg/L, meaning the studies that used higher concentrations are unrealistic. In this way, some studies [9,40,78,43,50,52,[68][69][70]76,77] run their experiments with lower concentrations, taking into consideration the allowed limits of chromium in water. Among these, Chowdhury and Yanful [76], Simeonidis et al [70] and Gifford et al [68] were the only ones that studied concentration equal or <2000 µg/L and Kaprara et al [40] studied the removal of 10 µg/L of chromium using Sn(II) oxy-hydroxides nanoparticles.…”

Rock magnetic characterization of the mine tailings in Portman Bay (Murcia, Spain) and its contribution to the understanding of the bay infilling process

“…Because magnetite is known to be an effective heavy metal captor (Biswal et al, 2013;Mayo et al, 2007), M s was compared with heavy metals content, specifically lead, zinc, iron, copper, arsenic, cadmium and mercury determined by XRF (Carmona Manzano, 2012) ( Table 2). We obtained the best correlations for lead, copper and arsenic (Fig.…”

Nanotubular Hard Carbon Derived from Renewable Natural Seed Gel for High Performance Sodium‐Ion Battery Anode

“…Herein, we report the effective use of natural gel derived hard carbon (NGHC) without using any activation agent as an anode for NIBs which is cost effective, readily scalable and first of its own kind. The source of carbon is the mucilage (gel) extracted from commonly used Ocimum Basilicum or Basil seeds (Indian name‐Sabja) rich in polysaccharides and lipids . The composition of the mucilage reported by Tharanathan et al ,.…”