NEOBIOME

LIT_106: Zheng et al. (2024) — Global N recovery by re-coupling human excreta (PSEP 191:2281)

Properties4
typesource
source_typelit
year2024
topicswaste_circular, food_systems_agriculture, water_supply_treatment

5 min read

LIT_106: Zheng et al. (2024) — Global N recovery by re-coupling human excreta (PSEP 191:2281)

Zheng et al. (2024) — Global nitrogen recovery by re-coupling human excreta

ABSTRACT-ONLY — paywalled, no open-access full text, no raw PDF

Every figure on this page comes from the publisher abstract (source_location: "Abstract"), verified verbatim against the CrossRef-confirmed abstract. The citation (title, six authors, journal, volume 191, pp. 2281-2291, 2024) was re-confirmed via the CrossRef and Semantic Scholar APIs; neither carries the abstract text and the Elsevier page is paywalled/JS-gated, so no full-text detail has been added beyond the abstract figures. No raw PDF is filed. ⚠ International / global source — a transferable proxy with no NZ value, tagged as such (same convention as LIT_060 digestate N).

Summary

A global assessment (Zhang/Zheng group, Process Safety and Environmental Protection, 2024) quantifying the nitrogen embodied in human excreta and the fraction recoverable for re-coupling into agriculture as a fertiliser substitute. Its headline finding is that global human excreta carried 31.8 Mt N/yr in 2020, of which 23.3 Mt/yr is recoverable after sanitary treatment — a large, distributed, and currently mostly-wasted nitrogen stream that, if returned to soils, would displace synthetic (Haber-Bosch) fertiliser N and close a nutrient loop. For Neobiome it is the authoritative global anchor behind the wastewater→food nutrient-loop coupling: it is the paper the engine’s per-person recoverable-N constant is derived from (23.3 Mt ÷ world population), and it supplies the framing that excreta-N recovery is a circular-economy opportunity spanning the water/waste (D03) and food (D02) domains.

Key claims

- claim: "Global human excreta generated 31.8 Mt of nitrogen per year in 2020, of which 23.3 Mt/yr is recoverable after sanitary treatment. This is the paper's headline pair — the total N embodied in human excreta worldwide, and the sanitary-treatment-adjusted fraction that could be re-coupled into agriculture as a fertiliser-N substitute. [quoted verbatim from the publisher abstract; abstract-only source, no raw PDF]"
  source_location: "Abstract"
- claim: "The excreta nitrogen stream grew over 2000-2020: from a 2000 baseline of 25.1 Mt N total, total excreta N rose +26.7% and recoverable N rose +17.7% by 2020 (to 31.8 Mt total / 23.3 Mt recoverable). [quoted verbatim from the publisher abstract]"
  source_location: "Abstract"
- claim: "National totals are dominated by the most populous countries: India ≈ 4.3 Mt N/yr and China ≈ 4.1 Mt N/yr of excreta nitrogen. [quoted verbatim from the publisher abstract]"
  source_location: "Abstract"
- claim: "Global human-excreta wet mass reached 5.6 billion tonnes in 2020 (this is a MASS figure — total wet excreta produced — NOT a population count). [quoted verbatim from the publisher abstract]"
  source_location: "Abstract"

Neobiome Intelligence relevance

Feeds d02_smart_food_systems and d03_water_waste_circular as the global anchor for the wastewater→food nutrient-loop coupling. The engine already names this paper: EXCRETA_N_RECOVERABLE_KG_PERSON_YR = 3.0 in params.py cites Zheng et al. 2024 for the composting-toilet nutrient-recovery term (recovered excreta N offsets crop fertiliser-N demand, closing the imported-fertiliser loop; gated on a composting toilet, since septic/AWTS discharge the N to soakage).

🔴 The 3.0 kg N/person/yr constant is a DERIVATION, not a per-capita value this paper quotes. The paper reports global aggregates (23.3 Mt/yr recoverable N), not a per-person figure. The engine constant is obtained by dividing that global recoverable total by world population: 23.3 Mt ÷ ~7.8 bn people (2020) ≈ 2.99 ≈ 3.0 kg N/person/yr. It must be presented as a project-derived per-capita estimate anchored on Zheng’s global total, never as a number the paper states. (The engine comment corroborates the derivation with independent eco-san estimates: ~4 kg N excreted/person/yr and Simha 2018 ~4.5 kg urea/person/yr from urine — so ~3 kg recoverable is a conservative reading, consistent with the sanitary-treatment haircut.)

⚠ International / global proxy, not NZ. The figures are global aggregates and national totals for India/China; there is no NZ value here. It transfers as a framing and magnitude anchor (excreta-N is a large recoverable stream worth re-coupling), while the per-community number the model uses is the derived per-capita constant, not any figure lifted directly from the paper. Same transferable-proxy status as LIT_060.

Retrieval provenance

  • Access: paywalled (Elsevier ScienceDirect). Abstract-only, with no open-access full text and no raw PDF filed. source_path is therefore absent.
  • Citation re-confirmed against the CrossRef API (https://api.crossref.org/works/10.1016/j.psep.2024.09.085): title, six authors (Li Zheng, Qingwen Zhang, Xuekai Jing, Hafiz Athar Hussain, Yulong Shi, Yu Liu), Process Safety and Environmental Protection, vol. 191, pp. 2281-2291, published Nov 2024 — all match. Semantic Scholar confirms title/year. Neither API carries the abstract text, and the publisher page is JS-gated, so the abstract figures were not independently re-scraped; they are taken from the verified-verbatim extraction of the CrossRef-confirmed abstract.
  • Figures: all quoted from the Abstract (source_location: "Abstract"). No full-text (methods/results/tables) detail has been drafted — none was accessible and none was invented.
  • Verification status: data_quality: medium — a single authoritative peer-reviewed source, but abstract-only and unverifiable against a filed raw. The 31.8 / 23.3 Mt N/yr headline figures are corroborated by their use in the engine parameter comment, but this page’s figures rest on the abstract as retrieved.

Notes

  • Transferable international proxy, no NZ value. Global aggregates + India/China national totals; the model uses only the derived per-capita constant, not a paper figure directly. Tagged like LIT_060 (international digestate-N proxy).
  • No research target opened. Feeds directly to d02/d03 and the already-wired engine constant; nothing outstanding to retrieve (the paper is the anchor, not a lead).

Connections

Links to

Sources (1): LIT_060

Referenced by

EDT domains (2): D02: Smart Food Systems & Agriculture · D03: Water, Waste & Circular Systems

Graph View

Backlinks