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Proceeding Paper

Sewage Sludge-Derived Biochar for Micropollutant Removal: A Brief Overview with Emphasis on European Water Policy †

1
Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy
2
Department of Civil and Environmental Engineering, University of Washington, 201 More Hall, Box 352700, Seattle, WA 98195-2700, USA
*
Author to whom correspondence should be addressed.
Presented at the International Conference EWaS5, Naples, Italy, 12–15 July 2022.
Environ. Sci. Proc. 2022, 21(1), 77; https://doi.org/10.3390/environsciproc2022021077
Published: 8 November 2022

Abstract

:
This work provides a brief overview of the application of Sewage Sludge-Derived Biochar (SSBC) for the removal of micropollutants from aqueous solutions and wastewater. A particular emphasis is placed on the adsorption efficiency of SSBC regarding the Priority Substances defined under the scope of the EU Water Framework Directive.

1. Introduction

Micropollutants (MPs) are organic or inorganic substances that occur in the aquatic environment at low concentrations (ng to µg). The discharge of MPs into natural water bodies is not yet regulated by the European Union (EU) [1]. However, under the scope of the Directive 2000/60/EC, also known as the Water Framework Directive (WFD), 45 priority substances (PSs) that pose a risk to the aquatic environment have been defined to date.
Since effluents of wastewater treatment plants (WWTPs) are a major source of micropollutants in natural water bodies [2], the expansion of existing WWTPs by advanced micropollutant removal stages could improve the status of European natural waters. However, only a few techniques for the removal of MPs are in operation in European WWTPs, and mainly in Switzerland and Germany [3]. In these techniques, adsorption on activated carbon (AC) is the most frequently used process [4,5,6]. To reduce the cost of MP removal by adsorption, the development of new economic adsorbents is essential [7]. Recently, sewage sludge-derived biochar (SSBC) has been identified as a promising alternative to AC with respect to the circular economy [8].
This work briefly reviews the application of SSBC for the removal of micropollutants from aqueous solutions with an emphasis on the PSs defined under the scope of the WFD. Finally, the limitations of this research and future perspectives for micropollutants’ removal from wastewater by SSBC are highlighted.

2. An Overview about the Removal of PSs by SSBC

This section aims to provide an overview of the state of the art regarding the application of SSBC for the removal of the 45 PSs defined under the WFD from aqueous solutions. A comprehensive number of studies (n > 2) were conducted on all metallic PSs:
  • Cadmium;
  • Lead;
  • Mercury;
  • Nickel and its compounds.
Several batch experiments using aqueous single-ion solutions proved the suitability of SSBC for the adsorptive removal of metallic PSs. The observed removal rates at the adsorption equilibrium varied in a wide range between <10% to ~100%, depending mainly on the SSBC dosages, initial metal concentrations, and the pH of the solution [9,10,11,12]. For Cadmium and lead removal, SSBC has shown better adsorption performances than commercial ACs tested as a reference [13,14,15,16]. When competitive metal ions were present in aqueous solutions, the adsorption efficiencies of SSBC decreased compared to single-ion solutions, with varying impacts for the respective ions. In these competitive ion studies, the adsorption performances of SSBC for metals followed this trend: Hg > Pb > Cd > Ni [16,17,18,19].
For the following organic PSs, a limited number of studies (n < 2) regarding their removal by SSBC have been carried out:
  • Anthracene;
  • Atrazine;
  • Benzene;
  • Nonylphenols;
  • Octylphenols;
  • Trifluralin;
  • Perfluorooctane sulfonic acid and its derivates (PFOS).
The application of SSBC for the adsorptive removal of anthracene, nonylphenols, octylphenols, and other stormwater pollutants from aqueous solutions has been investigated in one study. In batch adsorption and kinetic tests, SSBC showed similar adsorption efficiencies for anthracene, nonylphenols, and octylphenols to two commercial ACs [20].
One study has been carried out on the application of SSBC for atrazine removal from a model solution and real wastewater spiked with various xenobiotics. At high adsorbent dosages, a full elimination of atrazine from the model solution was obtained for SSBC and two reference ACs. At lower dosages, the atrazine elimination rates of the SSBC dropped, whereas the removal rates of the commercial ACs remained at 100% [21].
In sorption experiments for the removal of benzene from aqueous solutions, SSBC was a weaker adsorbent than commercial ACs [22].
SSBC can be used as an adsorbent and as a redox catalyst for trifluralin removal from aqueous solutions. When SSBC was simultaneously used as an adsorbent and a catalyst for the degradation of trifluralin in the presence of a thiol reactant, the removal performance of SSBC increased significantly compared to its single use as an adsorbent [23].
Based on adsorption experiments, SSBC made from biosolids was evaluated as an excellent low-cost adsorbent for removing PFOS from aqueous solutions [24]. Accordingly, thermochemically activated SSBC exhibited a similar PFOS adsorption capacity to commercial ACs in another study [25].
For most of the PSs, no studies regarding SSBC’s application in aqueous solutions are available. This concerns the following substances:
  • Alachlor;
  • Atrazine;
  • Brominated diphenylethers (PBDE);
  • Chloroalkanes (C10–13);
  • Chlorfenvinphos;
  • Chlorpyrifos;
  • 1,2-dichloroethane;
  • Dichloromethane;
  • Di(2-ethylhexyl)phthalate (DEHP);
  • Diuron;
  • Endosulfan;
  • Fluoranthene;
  • Hexachlorobenzene;
  • Hexachlorobutadiene;
  • Hexachlorocyclohexane;
  • Isoproturon;
  • Pentachlorobenzene;
  • Pentachlorophenol;
  • Polyaromatic hydrocarbons (PAH);
  • Simazine;
  • Tributyltin compounds;
  • Trichlorobenzenes;
  • Trichloromethane (chloroform);
  • Trifluralin;
  • Dicofol;
  • Quinoxyfen;
  • Dioxins and dioxin-like compounds;
  • Aclonifen;
  • Bifenox;
  • Cybutryne;
  • Cypermethrin;
  • Dichlorvos;
  • Hexabromocyclododecanes (HBCDD);
  • Heptachlor and heptachlor epoxide;
  • Terbutryn.

3. Conclusions

SSBC has great potential as a low-cost adsorbent for the removal of micropollutants from wastewater, especially for dissolved metals. However, the use of SSBCs has not yet been investigated for most of the organic PSs under the WFD. Batch adsorption studies for all relevant PSs are required for the further development of SSBC applications. In terms of the circular economy, concepts should be developed for the combined production and application of SSBC at real WWTPs. Finally, the feasibility of those concepts should be tested by installing and operating SSBC production and adsorber pilot plants on WWTP sites.

Author Contributions

Conceptualization, C.G. and V.N.; methodology, C.G. and V.N.; validation, V.B., T.Z., G.V.K. and V.N.; formal analysis, C.G.; investigation, C.G.; resources, V.B., T.Z. and V.N.; data curation, C.G.; writing—original draft preparation, C.G.; writing—review and editing, V.B., T.Z., G.V.K. and V.N.; visualization, C.G.; supervision, V.B., T.Z. and V.N.; project administration, V.B., T.Z. and V.N. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Gorito, A.M.; Lado Ribeiro, A.R.; Pereira, M.F.R.; Almeida, C.M.R.; Silva, A.M.T. Advanced Oxidation Technologies and Constructed Wetlands in Aquaculture Farms: What Do We Know so Far about Micropollutant Removal? Environ. Res. 2022, 204, 111955. [Google Scholar] [CrossRef]
  2. Völker, J.; Castronovo, S.; Wick, A.; Ternes, T.A.; Joss, A.; Oehlmann, J.; Wagner, M. Advancing Biological Wastewater Treatment: Extended Anaerobic Conditions Enhance the Removal of Endocrine and Dioxin-like Activities. Environ. Sci. Technol. 2016, 50, 10606–10615. [Google Scholar] [CrossRef] [PubMed]
  3. da Silveira Barcellos, D.; Procopiuck, M.; Bollmann, H.A. Management of Pharmaceutical Micropollutants Discharged in Urban Waters: 30 years of Systematic Review Looking at Opportunities for Developing Countries. Sci. Total Environ. 2022, 809, 151128. [Google Scholar] [CrossRef] [PubMed]
  4. F&E-Projekte zur Abwasserbeseitigung. Available online: https://www.lanuv.nrw.de/umwelt/wasser/abwasser/foerderung-von-fe-projekten-zur-abwasserbeseitigung/gefoerderte-projekte?tx_cartproducts_products%5Bproduct%5D=1017&cHash=2bbc2e64a36207438a4fd1de236dd850 (accessed on 14 February 2022).
  5. Kompetenzzentrum Spurenstoffe (KomS) Baden-Württemberg. Micropollutants in Wastewater—Action Recommendation for Municipalities, 1st ed.; Kompetenzzentrum Spurenstoffe (KomS) Baden-Württemberg: Stuttgart, Germany, 2021; p. 10. [Google Scholar]
  6. Upgrading of Swiss Wastewater Treatment Plants (WWTP). Available online: https://micropoll.ch/en/home/ (accessed on 14 February 2022).
  7. Xiao, Y.; Raheem, A.; Ding, L.; Chen, W.H.; Chen, X.; Wang, F.; Lin, S.L. Pretreatment, Modification and Applications of Sewage Sludge-Derived Biochar for Resource Recovery- A Review. Chemosphere 2022, 287, 131969. [Google Scholar] [CrossRef] [PubMed]
  8. Regkouzas, P.; Diamadopoulos, E. Adsorption of Selected Organic Micro-Pollutants on Sewage Sludge Biochar. Chemosphere 2019, 224, 840–851. [Google Scholar] [CrossRef]
  9. Chen, T.; Zhou, Z.; Han, R.; Meng, R.; Wang, H.; Lu, W. Adsorption of Cadmium by Biochar Derived from Municipal Sewage Sludge: Impact Factors and Adsorption Mechanism. Chemosphere 2015, 134, 286–293. [Google Scholar] [CrossRef]
  10. Zhai, Y.B.; Zeng, G.M.; Wang, L.F.; Wei, X.X.; Li, C.T.; Li, S.H. Removal of Copper and Lead Ions from Aqueous Solutions by Adsorbent Derived from Sewage Sludge. Int. J. Environ. Waste Manag. 2011, 8, 229–240. [Google Scholar] [CrossRef]
  11. Zhang, F.S.; Nriagu, J.O.; Itoh, H. Mercury Removal from Water Using Activated Carbons Derived from Organic Sewage Sludge. Water Res. 2005, 39, 389–395. [Google Scholar] [CrossRef]
  12. Mourgela, R.N.; Regkouzas, P.; Pellera, F.M.; Diamadopoulos, E. Ni(II) Adsorption on Biochars Produced from Different Types of Biomass. Water Air Soil Pollut. 2020, 231, 1–16. [Google Scholar] [CrossRef]
  13. de Filippis, P.; di Palma, L.; Petrucci, E.; Scarsella, M.; Verdone, N. Production and Characterization of Adsorbent Materials from Sewage Sludge by Pyrolysis. Chem. Eng. Trans. 2013, 32, 205–210. [Google Scholar] [CrossRef]
  14. Chen, T.; Zhang, Y.; Wang, H.; Lu, W.; Zhou, Z.; Zhang, Y.; Ren, L. Influence of Pyrolysis Temperature on Characteristics and Heavy Metal Adsorptive Performance of Biochar Derived from Municipal Sewage Sludge. Bioresour. Technol. 2014, 164, 47–54. [Google Scholar] [CrossRef] [PubMed]
  15. Li, L.Y.; Gong, X.D.; Abida, O. Waste-to-Resources: Exploratory Surface Modification of Sludge-Based Activated Carbon by Nitric Acid for Heavy Metal Adsorption. Waste Manag. 2019, 87, 375–386. [Google Scholar] [CrossRef] [PubMed]
  16. Gutierrez-Segura, E.; Colin-Cruz, A.; Fall, C.; Solache-Rios, M.; Balderas-Hernández, P. Comparison of Cd-Pb Adsorption on Commercial Activated Carbon and Carbonaceous Material from Pyrolysed Sewage Sludge in Column System. Environ. Technol. 2009, 30, 455–461. [Google Scholar] [CrossRef] [PubMed]
  17. Xie, R.; Jiang, W.; Wang, L.; Peng, J.; Chen, Y. Effect of Pyrolusite Loading on Sewage Sludge-Based Activated Carbon in Cu(II), Pb(II), and Cd(II) Adsorption. Environ. Prog. Sustain. Energy 2013, 32, 1066–1073. [Google Scholar] [CrossRef]
  18. Fritzmorris, K.B.; Lima, I.M.; Marshall, W.E.; Reimers, R.S. Anion and Cation Removal from Solution Using Activated Carbons from Municipal Sludge and Poultry Manure. J. Residuals Sci. Technol. 2006, 3, 161–167. [Google Scholar]
  19. Otero, M.; Rozada, F.; Morán, A.; Calvo, L.F.; García, A.I. Removal of Heavy Metals from Aqueous Solution by Sewage Sludge Based Sorbents: Competitive Effects. Desalination 2009, 239, 46–57. [Google Scholar] [CrossRef]
  20. Björklund, K.; Li, L.Y. Adsorption of Organic Stormwater Pollutants onto Activated Carbon from Sewage Sludge. J. Environ. Manag. 2017, 197, 490–497. [Google Scholar] [CrossRef] [Green Version]
  21. Kirschhöfer, F.; Sahin, O.; Becker, G.C.; Meffert, F.; Nusser, M.; Anderer, G.; Kusche, S.; Klaeusli, T.; Kruse, A.; Brenner-Weiss, G. Wastewater Treatment—Adsorption of Organic Micropollutants on Activated HTC-Carbon Derived from Sewage Sludge. Water Sci. Technol. 2016, 73, 607–616. [Google Scholar] [CrossRef]
  22. Kah, M.; Sun, H.; Sigmund, G.; Hüffer, T.; Hofmann, T. Pyrolysis of Waste Materials: Characterization and Prediction of Sorption Potential across a Wide Range of Mineral Contents and Pyrolysis Temperatures. Bioresour. Technol. 2016, 214, 225–233. [Google Scholar] [CrossRef]
  23. Oh, S.Y.; Son, J.G.; Chiu, P.C. Biochar-Mediated Reductive Transformation of Nitro Herbicides and Explosives. Environ. Toxicol. Chem. 2013, 32, 501–508. [Google Scholar] [CrossRef]
  24. Kundu, S.; Patel, S.; Halder, P.; Patel, T.; Hedayati Marzbali, M.; Pramanik, B.K.; Paz-Ferreiro, J.; de Figueiredo, C.C.; Bergmann, D.; Surapaneni, A.; et al. Removal of PFASs from Biosolids Using a Semi-Pilot Scale Pyrolysis Reactor and the Application of Biosolids Derived Biochar for the Removal of PFASs from Contaminated Water. Environ. Sci. Water Res. Technol. 2021, 7, 638–649. [Google Scholar] [CrossRef]
  25. Mohamed, B.A.; Li, L.Y.; Hamid, H.; Jeronimo, M. Sludge-Based Activated Carbon and Its Application in the Removal of Perfluoroalkyl Substances: A Feasible Approach towards a Circular Economy. Chemosphere 2022, 294, 133707. [Google Scholar] [CrossRef] [PubMed]
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MDPI and ACS Style

Gatz, C.; Belgiorno, V.; Zarra, T.; Korshin, G.V.; Naddeo, V. Sewage Sludge-Derived Biochar for Micropollutant Removal: A Brief Overview with Emphasis on European Water Policy. Environ. Sci. Proc. 2022, 21, 77. https://doi.org/10.3390/environsciproc2022021077

AMA Style

Gatz C, Belgiorno V, Zarra T, Korshin GV, Naddeo V. Sewage Sludge-Derived Biochar for Micropollutant Removal: A Brief Overview with Emphasis on European Water Policy. Environmental Sciences Proceedings. 2022; 21(1):77. https://doi.org/10.3390/environsciproc2022021077

Chicago/Turabian Style

Gatz, Christoph, Vincenzo Belgiorno, Tiziano Zarra, Gregory V. Korshin, and Vincenzo Naddeo. 2022. "Sewage Sludge-Derived Biochar for Micropollutant Removal: A Brief Overview with Emphasis on European Water Policy" Environmental Sciences Proceedings 21, no. 1: 77. https://doi.org/10.3390/environsciproc2022021077

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