Polymer-based nanocomposite adsorbents for resource recovery from wastewater

Abstract

Adsorption is alternative technique for recovery of nutrient resources with no/less secondary pollution. PNC adsorbents are effective for removal and recovery of nutrient resources, and reusing nutrients as fertilizer could prevent eutrophication.

Lignin Smart Nanoparticles for Effective and Eco-Friendly Resource Recovery from Wastewater: Status, Challenges, and Opportunities

“…Nonetheless, the physicochemical properties of lignin materials vary with process conditions (e.g., pH, temperature, and salt concentration) and in turn will affect the adsorption capacity. 5,35,36,57 In this perspective, we delve into these characteristic-dependent performances to evaluate the performance of lignin-based materials against that of metallic nanoparticles and synthetic polymeric nanoparticles and commercial technologies. These advantages and disadvantages are discussed comprehensively in Section 4.…”

“…Specifically, adsorption is a clean, low-cost, selective, and effective process. , The characteristics of an effective adsorbent are high adsorption capacity, thermal stability, efficiency, reuse, and recycle capability. , From these perspectives, activated carbon, which is the primary adsorbent used at an industrial scale, suffers majorly from high costs, and poor affinity to hydrophilic resources such as anionic dyes, and lignin nano- and microparticles being amphiphilic, are potential competitive adsorbents. Nonetheless, the physicochemical properties of lignin materials vary with process conditions (e.g., pH, temperature, and salt concentration) and in turn will affect the adsorption capacity. ,,, In this perspective, we delve into these characteristic-dependent performances to evaluate the performance of lignin-based materials against that of metallic nanoparticles and synthetic polymeric nanoparticles and commercial technologies. These advantages and disadvantages are discussed comprehensively in Section .…”

“…Among the most prominent advanced technologies for resource recovery from wastewater, including zero-liquid discharge (thermally driven), membrane-based reverse osmosis, electrodialysis, forward osmosis, activated carbon, microbial electrochemical technologies, chemical precipitation, and polymeric membranes (including ultra- and nanofiltration systems), there remain the issues of high energy requirements, high cost, limited efficiency, noncarbon neutrality, poor resource recovery resulting in water body eutrophication, sludge formation, and toxic gas release (e.g., CO 2 , N 2 O, and CH 4 ). ,− Green lignin nanoparticles have the potential to efficiently recover metals, ,,, toxic dyes, nutrients, pharmaceuticals, oil, microorganisms, and PFAS from wastewater, particularly via adsorption mechanisms . Additionally, lignin nanoparticles have also been tested as effective components of wastewater treatment membranes .…”

“…An imminent transition from fossilized to renewable feedstocks to produce sustainable energy, fuels, commodity chemicals and advanced materials is needed to mitigate climate change, environmental contamination, and support the rapid population growth around the globe. , Wastewater, composed of 1% dissolved and suspended solids, and 99% water has been recently regarded as a mine of valuable resources, − with approximately 380 trillion L/year of wastewater produced globally, ∼16 times the volume emissions of CO 2 from fossil fuels and industry worldwide in 2022 . This diverse, unsteady, and heterogeneous resource may contain microorganisms (e.g., infectious bacteria, viruses, protozoa, and helminths), minerals (e.g., Ca, Mn, and Mg) , nutrients (e.g., P, N, and K), metals (e.g., Cu, Co, Cr, and Zn), dyes, pharmaceuticals, per- and polyfluorinated substances (PFAS), and energy, among others. ,− Exploiting this reservoir may not only increase access to potable water, decrease the concentration of contaminants discharged into water bodies, and minimize pollution that results in problems such as eutrophication but also establish a route for the sustainable circularity of resources, thus improving the overall economic and ecological profitability in wastewater plants and, particularly, supporting the worldwide net-zero greenhouse gas emissions target projected to be reached between 2050 and 2080s. ,− …”

“…Of the technologies being researched, electrochemical, biologically activated membranes, and adsorption systems stand out. , Recent reports have demonstrated the efficacy of nanomaterials to extract dyes, and low-, medium-, and high-toxicity metals from wastewater via accessible and low-cost adsorption processes. ,, The precursors for these nanomaterials are predominantly carbon-based (e.g., graphene, carbon nanotubes, membranes, and activated carbon), metal oxide-based (e.g., MgO, CdO, Fe 3 O 4 ), silica-based (e.g., silica nanoparticles), and to a lesser extent polymer-based (e.g., nanomaterials, and aerogels). ,, Polymer-based, specifically biopolymers, could significantly enhance advanced adsorption processes technically, socio-economically, and environmentally. In fact, lignin, one the major constituents of lignocellulosic biomass (nonedible) represents the second-most abundant biopolymer after cellulose (∼40%, w/w cellulose, and ∼25% w/w lignin of lignocellulosic biomass); it is a renewable reserve of aromatic compounds, accounting for about 30% of the total nonfossil carbon on Earth, with carbon representing about 60% of the structure of lignin, , as polymer chains and nanoparticles are efficacious at removing various contaminants from wastewater, including metals, dyes, pharmaceuticals, and nutrients, making it a potential efficacious adsorbent for resource recovery from wastewater. ,− Although nano- and microstructured lignin particles are highly attractive adsorption materials, their industrial valorization is hampered by the heterogeneity of the polymer.…”