nano-adsorption, and nanosensing) are employed to protect the water system [20]. Nanocatalyst with advantageous modes of coordination like ·radical reactions, e− transfer, redox (photo), atomic/molecular interaction (π-π, electro-static, H-bond, and Van der Waals), ligand transference, and adsorption aids in supporting the nanocatalytic activities [223].
Functionalization offers an improved resolution to tackle the hitch delivered by simple NMs. FNMs as nanocatalysts like membranes, adsorbents, and electrodes, utilizing the natural resource of solar light/electrical energy, help in degrading the TP, thus, ultimately in overcoming the bottle-neck faced while using the traditional products. Thus, effective functionalization can be achieved by adopting numerous options available based upon the requirement of the situation. Direct, post-synthetic, co-condensation, grafting (polymers), physisorption (non-covalent), chemisorption (covalent), surface oxidation, doping heteroatoms, alkali activation, sulfonation, polymer coating, and many more. Hence, delivering an improved shift in significant properties like chemical compatibility, wettability, texture with augmented unique surface-area/pore-volume, absorptivity, and enhanced mechanical-strength [20].
Every new technological advancement has its own significant demerits and merits for toxin elimination. The problems confronted in effluent-water or in other water management systems by NMs are significantly important. However, most of them primarily are only transient (trials conducted or financial). It is anticipated that new novel advancements in nanotechnology by cautious management evades unintended outcomes and can incessantly deliver a robust output in effluent-water or in other water management. The cost of time and money, energy consumptions, and compatibility of the subsisting substructure will govern the full-scale utilization [224].
As a wrap up, application of different types of FNMs used for remediation of TPs like organics (dyes, drugs, pesticides, health care, and endocrine disruptors) from (industrial/pharmaceutical) effluents, and agricultural debris/biological/inorganics (heavy-metals and carcinogenic components) have been discussed and summarized, in reference to optimization requirement and key role enhancers.
FNMs as nanocatalyst are segmented and reviewed as EC, EFC, PF catalyst, PCs, and anti-microbials, with various informative trials delivered in the recent past for protecting the water resources. FNMs supported on NRs, NFs, NWs, NTs, NPs, and NSs, of metal/metal-oxides, MNPs, carbonaceous (G/GO/CNT/fullerenes/g-C3N4), QDs, CQDs, nitrides, and natural/synthetic polymers (chitosan) as some essentials have delivered a non-toxic, less-energy, cost-effective, and multi reusable products, for sustainability. Economic deliverables are noticed while using functionalized membrane/adsorbents that offer a better solution and multi-reusability to get rid of the contaminants like organismal (protozoa, bacteria, viruses, fungi), organic material, colloidal or suspended micro/macro solids, and metallic/nonmetallic present. The potential resistance of bacterial toward broad-spectrum antibiotics lowers the intensity and increases the quantity of the drugs to be administered. Similarly, the useful bacteria in the aquatic system are devoid of their potency by these drugs that pollute the water system.
Ongoing challenge for scientific community is to develop and produce competent components with high mechanical and electronic properties, economical, bio-degradable and eco-friendly, not for a single platform but, for a large-scale wider application. The cross-intermingling interaction between the base-hosts and supporters as surface modifiers is responsible for high stability and potentiality for field submissions for natural water/waste effluent water management are some noteworthy points in developing and utilizing the FNMs.
With refined intrinsic characteristics, reusability and economical profits, FNMs are found to exhibit a vivid scope in water resource management. FNMs, although economical, should be tailored in a better way with ecological and health hazard concerns. Additionally, engineering and commercialization pertaining to market potentiality, with regulations and co-ordinating policies, need to be altered for eco-friendly approaches.
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