Tannery wastewater secondary resource
Aqueous waste streams from tanning operations, represented here by conventionally treated effluent from the Acque del Chiampo plant in Arzignano, Italy. This heterogeneous secondary resource is distinct from wastewater-treatment sludge, chromium-tanned leather shavings, synthetic chromium solutions and elemental chromium. The accepted laboratory study concerns further removal of residual source-assigned Cr(III) using dead fungal biomass; composition and performance are specific to the tested feeds. No constituent criticality is inherited.
Microbial & Biochemical Mechanisms (1)
Chromium removal by heat-inactivated fungal biomass
biosorption
Microbial
Associated Organisms:
Cunninghamella elegans (NCBITaxon:4853)
Heat-inactivated Cunninghamella elegans biomass decreased aqueous chromium in real, previously treated tannery effluent. The study interprets this as biosorption. Biomass preparation, feed chemistry and contact time affect the reported removal; active fungal metabolism, chromium redox conversion, a complete metal balance and an isolated chromium product were not demonstrated.
Experimental Context & Analytical Limits:
Source-reported Cunninghamella elegans MUT 2861 came from the Mycotheca Universitatis Taurinensis collection. Biomass was cultivated for seven days at 30°C and 110 rpm in glucose-based EQ medium or ST medium containing 18 g/L potato starch in place of glucose, then washed, homogenized and autoclaved in saline at 121°C for 30 min. The detailed pretreatment comparison uses ST-grown biomass. Additional treatments were lyophilization/powdering or boiling in 0.5 M NaOH for 15 min followed by rinsing to wash pH 7.0–7.2. Batch assays used 15 g fresh inactivated biomass, or 1.5 g lyophilized biomass, in 150 mL effluent in 250 mL flasks at 30°C and 110 rpm for up to 24 h, with no-biomass controls and triplicate trials. Real effluent collected after chemical, physical and biological treatment had pH 7.80–8.20 and source-assigned Cr(III) 0.31–0.56 mg/L across samples. Cr(VI) was reported absent without a stated detection limit. The real assays were not pH-buffered. Table 1 describes annual monitoring averages, not the exact recipe of every assay batch. Industrial feed origin does not establish industrial deployment of fungal treatment.
Source-reported Cunninghamella elegans MUT 2861 came from the Mycotheca Universitatis Taurinensis collection. Biomass was cultivated for seven days at 30°C and 110 rpm in glucose-based EQ medium or ST medium containing 18 g/L potato starch in place of glucose, then washed, homogenized and autoclaved in saline at 121°C for 30 min. The detailed pretreatment comparison uses ST-grown biomass. Additional treatments were lyophilization/powdering or boiling in 0.5 M NaOH for 15 min followed by rinsing to wash pH 7.0–7.2. Batch assays used 15 g fresh inactivated biomass, or 1.5 g lyophilized biomass, in 150 mL effluent in 250 mL flasks at 30°C and 110 rpm for up to 24 h, with no-biomass controls and triplicate trials. Real effluent collected after chemical, physical and biological treatment had pH 7.80–8.20 and source-assigned Cr(III) 0.31–0.56 mg/L across samples. Cr(VI) was reported absent without a stated detection limit. The real assays were not pH-buffered. Table 1 describes annual monitoring averages, not the exact recipe of every assay batch. Industrial feed origin does not establish industrial deployment of fungal treatment.
Curated Evidence Points:
Support
Source:
prigione2009
Methods 2.4–2.6 and Results 3.2/Table 3 (author-manuscript article p.10, PDF p.12) support laboratory aqueous removal by inactive biomass. The source reports unchanged chromium in no-biomass controls. After 24 h, C. elegans grown on ST removed 37.61 ± 1.48% versus 29.73 ± 0.00% for EQ-grown biomass (means ± standard deviations). These are solution-removal percentages for this feed, not recovered-product yields or universal capacities.
Support
Source:
prigione2009
Table 4 on the same page distinguishes two real-feed batches. At initial 0.39 ± 0.00 mg/L, untreated ST biomass removed 37.61 ± 1.48% after 24 h versus 28.34 ± 0.00% for lyophilized biomass. At initial 0.42 ± 0.02 mg/L, untreated ST biomass removed 26.46 ± 1.38% versus 32.05 ± 1.38% for NaOH-pretreated biomass. The alkali effect must be compared within its own feed batch; it is not a direct comparison against the 37.61% arm. Lyophilization did not improve this real-feed endpoint.
Partial
Source:
prigione2009
Methods 2.6 and Table 4 define sorption capacity from disappearance of aqueous Cr(III) divided by final dry biomass mass. They do not directly measure a complete biomass-bound chromium inventory, desorption or an isolated metal product. The cited analytical procedure is APAT CNR IRSA 3010/3020, Man 29 (2003); the manuscript does not give an explicit instrument, detection limit or complete speciation balance. Stable no-biomass controls support biomass-associated removal but do not isolate surface binding from biomass-induced local precipitation or other matrix effects.
Partial
Source:
prigione2009
Results 3.3/Table 5 (article p.12, PDF p.14) concern separate chromium-nitrate solutions at initial pH 5, not the real pH approximately 8 effluent. Their larger removal/capacity values cannot be transferred to tannery wastewater. The paper reports no lyophilized-biomass removal in those synthetic assays, with data not shown. Proposed proton/metal exchange and effects of effluent ligands remain interpretations: pH, concentration and solution composition differ, and the study does not independently isolate ligand causality or provide direct molecular binding evidence.
Context_only
Source:
prigione2009
Results 3.2/Figure 1 (article p.11, PDF p.13) compare another real feed, initially 0.44 mg/L, under clariflocculation, fungal biosorption and the combination. Approximately 16%, 40% and 44% removal, respectively, are source-reported separate treatment outcomes, not additive percentages or proof of synergy. This laboratory comparison and the plant flow cited in Methods do not demonstrate full-scale fungal deployment, legal compliance, comprehensive detoxification or product recovery.
Partial
Source:
prigione2009
The experimental protocol specifies boiling NaOH pretreatment, whereas the Discussion refers to cold-alkali cell-wall mechanisms. The executed boiling protocol is retained; the explanatory wording is not treated as direct evidence for a particular cell-wall alteration. No measured gas, redox or intracellular uptake mechanism is claimed.
Context_only
Source:
ncbi4853
The official entry resolves Cunninghamella elegans at species rank. MUT 2861 is retained only as the primary paper’s stock designation; the species identifier is not a strain accession or independent authentication of that culture.
Sources & References
-
prigione2009: Valeria Prigione, Mirco Zerlottin, Daniele Refosco, Valeria Tigini, Antonella Anastasi and Giovanna Cristina Varese (2009). Chromium removal from a real tanning effluent by autochthonous and allochthonous fungi. Bioresource Technology 100(11):2770–2776. DOI 10.1016/j.biortech.2009.01.002; PMID 19211244. Complete 23-page University of Turin author manuscript inspected, including two repository pages and 21 numbered article pages; Methods 2.1–2.6, Results 3.2–3.3, Tables 1–5 and Figure 1. This is not an independently compared version-of-record PDF.
https://doi.org/10.1016/j.biortech.2009.01.002 (accessed 2026-10-16) -
ncbi4853: NCBI Taxonomy 4853: Cunninghamella elegans, species. Official browser entry verifies the species label and rank, not the experimental MUT 2861 stock.
https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=4853&mode=Info (accessed 2026-10-16)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-16T01:32:20.093090Z |
Codex (GPT-6; codex) | CREATE | Created a tannery wastewater resource record from the complete Prigione2009 author manuscript, preserving inactive fungal biomass, real-feed batch differences, synthetic-solution limits and the distinction between removal and product recovery. |
Record source: data/records/tannery-wastewater.yaml