Utilizing of Mushrooms as an Effective Biosorbent ...

Below is a compact primer you can use as a starting point for a seminar‑talk, grant proposal, or experimental design on using mushrooms (fruit‑body, mycelium, or spent‑substrate–derived biochar) as biosorbents for removing vanadium species from water. Citations are given so you can pull the original papers for full details.

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1. Why target vanadium – and why biosorption?

Item	Key points
Environmental concern	Vanadium(V) occurs as mobile oxy‑anions (H₂VO₄⁻, HVO₄²⁻, V₁₀O₂₈⁶⁻, etc.) that are toxic above ~50 µg L⁻¹ and common in steel‑making, mining, oil‑combustion and battery industries.
Limits	Many jurisdictions now propose discharge limits ≤ 50 µg L⁻¹; Polish regulations already set 0.05 mg L⁻¹ for surface waters. ResearchGate
Why biosorption?	Low‑cost solids, no sludge chemicals, good selectivity after surface tuning, and the sorbent itself is a waste stream.

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2. What makes mushroom biomass a “natural ion‑exchange resin”?

Component	Functional groups that bind vanadate
Chitin / chitosan	–NH₃⁺ (protonated amine) for anion exchange, –OH for ligand exchange SpringerOpen
β‑Glucans & proteins	carboxyl‑, phosphate‑, phenolic‑OH groups (complexation, hydrogen bonding) ✔
Porous skeleton	50–400 m² g⁻¹ after pyrolysis to biochar → more sites + faster kinetics ResearchGate

At pH 1‑3 the biomass surface is strongly protonated, giving it a net positive charge ideally suited for electrostatic attraction of VO₃⁻/H₂VO₄⁻. Above pH ~6 both the sorbent (de‑protonated carboxylates) and vanadate (divalent anion) carry negative charge and capacity collapses – a point to remember for column operation.

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3. Snapshot of recent laboratory performance

Mushroom‑derived sorbent	Operating pH & T	Initial V(V) (mg L⁻¹)	q<sub>max</sub> (mg g⁻¹)	Notes / Ref
SMS biochar (BC3) from oyster‑mushroom farm‑waste	3.0 / 25 °C	50	≈1.0 mg g⁻¹ (Langmuir); pseudo‑2nd‑order kinetics; 80 % removal in 90 min ResearchGate
Live Pleurotus ostreatus mycelial pellets	2.5	20	4.5–6	Living uptake + bioaccumulation (older, but shows mechanism) SpringerOpen
Composite fungal membrane (Pleurotus mycelium + bacterial cellulose)	2–6	10	18–22	Regenerable with 0.1 M NaOH, 5 % loss after 4 cycles ScienceDirect
Mycelium loaded with nano‑polystyrene to pre‑complex vanadate (“nPS‑P. ostreatus”)	3	30	12	Nanoplastics raise surface‑area & electron‑rich sites – study explores reuse as V‑based battery cathode ScienceDirect

Take‑home: raw biomass works, but thermal (≤700 °C) or chemical modification generally multiplies capacity by 2‑20× and improves mechanical stability for packed beds.

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4. Process variables that matter most

Variable	Practical window	Rationale
pH	1.5 – 3.5 for V(V); 3–5 for V(IV)	Maximises electrostatic attraction of anionic vanadate while avoiding dissolution of chitin.
Contact time	30–120 min (batch); EBCT = 3–10 min (columns)	Pseudo‑second‑order chemisorption dominates.
Competing anions	PO₄³⁻ ≫ SO₄²⁻ ≈ NO₃⁻ interference. Pre‑acidify or use Ca/Fe‑impregnated biochar to restore selectivity.
Temperature	Endothermic; 5–10 % ↑ in q<sub>max</sub> when going from 20 → 40 °C.
Regeneration	0.1–0.2 M NaOH or 0.05 M Na₃PO₄ desorbs 85–95 %; capacity loss ≤ 10 % over 3–5 cycles.

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5. Building a lab‑scale workflow

1. Feedstock – collect spent mushroom substrate (SMS) or fruit bodies rejected for food use.
2. Pretreatment – wash → oven‑dry (60 °C) → mill to 0.2–1 mm.
3. Activation options
   • Low‑temp acid wash (0.5 M HCl) → rinsing → ready‑to‑use biomass.
   • Pyrolysis at 500 °C (N₂, 2 h) → yields high‑surface‑area biochar (good for columns).
   • Fe/Ca impregnation (0.05 M FeCl₃ or Ca(OH)₂ slurry) before pyrolysis gives dual‑function anion / cation sites.
4. Isotherm & kinetics – run batch tests at pH 2, 10–100 mg L⁻¹ V, 25 °C. Fit Langmuir & pseudo‑2nd‑order.
5. Column up‑scaling – pack 10 cm × 1 cm ID glass column, EBCT ≈ 5 min. Monitor breakthrough (C/C₀ = 0.05) and regenerate with 0.1 M NaOH.
6. Spent sorbent handling – options: (i) mild acid leach to recover vanadium for catalyst use; (ii) convert metal‑loaded biochar to V‑rich fertiliser (dilution critical; regulatory check).

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6. Where the research frontier is moving

• Engineered myco‑composites – embedding mycelium in alginate, silica, or electrospun fibers for hybrid filtration membranes.
• Genetic tuning of cell‑wall chemistry – CRISPR knock‑ins of chitin de‑acetylases to raise chitosan content and boost anion binding.
• Cascade valorisation – using V‑laden biochar as a vanadium precursor for Na‑ion or Li‑S battery cathodes (proof‑of‑concept shown by nano‑PS/P. ostreatus study).
• Real effluent work – little data exist for high‑chloride power‑plant blow‑down streams; competing Cl⁻ can form VOCl₆³⁻ complexes that behave differently.

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7. Take‑away messages

• Feasible – even unmodified SMS can capture 0.8–1.2 mg V g⁻¹; simple acid or iron treatments boost this an order of magnitude.
• Selective under acidic conditions – ideal for acidic mine drainage or pickling baths; less suited for circum‑neutral waters unless surface is metal‑impregnated.
• Circular – turns mushroom‑farm waste into a consumable water‑treatment medium and provides a route to recover a strategic metal.

Feel free to let me know if you’d like deeper detail on kinetics modelling, fixed‑bed design equations, or a side‑by‑side cost comparison with commercial anion‑exchange resins.