Aerobic Granular Sludge for Complex Heavy Metal-containing Wastewater Treatment: Characterization, Performance, and Mechanisms Analysis

Overview

Journal Front Microbiol

Specialty Microbiology

Date 2024 Feb 15

PMID 38357352

Authors

Chong Liu

Yao Shen

Yuguang Li

Fengguang Huang

Shuo Wang

Ji Li

Affiliations

Soon will be listed here.

Abstract

Complex heavy metal (HM)-containing wastewater discharges pose substantial risks to global water ecosystems and human health. Aerobic granular sludge (AGS) has attracted increased attention as an efficient and low-cost adsorbent in HM-containing wastewater treatment. Therefore, this study systematically evaluates the effect of Cu(II), Ni(II), and Cr(III) addition on the characteristics, performance and mechanism of AGS in complex HM-containing wastewater treatment process by means of fourier transform infrared spectroscopy, inductively coupled plasma spectrocopcy, confocal laser scanning microscopy, extracellular polymeric substances (EPS) fractions detection and scanning electron microscope-energy dispersive X-ray. The results showed that AGS efficiently eliminated Cu(II), Ni(II), and Cr(III) by the orchestrated mechanisms of ion exchange, three-layer EPS adsorption [soluble microbial products EPS (SMP-EPS), loosely bound EPS (LB-EPS), tightly bound EPS (TB-EPS)], and inner-sphere adsorption; notably, almost 100% of Ni(II) was removed. Three-layer EPS adsorption was the dominant mechanism through which the HM were removed, followed by ion exchange and inner-sphere adsorption. SMP-EPS and TB-EPS were identified as the key EPS fractions for adsorbing Cr(III) and Cu(II), respectively, while Ni(II) was adsorbed evenly on SMP-EPS, TB-EPS, and LB-EPS. Moreover, the rates at which the complex HM penetrated into the granule interior and their affinity for EPS followed the order Cu(II) > Ni(II) > Cr(III). Ultimately, addition of complex HM stimulated microorganisms to excrete massive phosphodiesterases (PDEs), leading to a pronounced decrease in cyclic diguanylate (c-di-GMP) levels, which subsequently suppressed EPS secretion due to the direct linkage between c-di-GMP and EPS. This study unveils the adaptability and removal mechanism of AGS in the treatment of complex HM-containing wastewater, which is expected to provide novel insights for addressing the challenges posed by intricate real wastewater scenarios.

References

Liang Z, Li W, Yang S, Du P . Extraction and structural characteristics of extracellular polymeric substances (EPS), pellets in autotrophic nitrifying biofilm and activated sludge. Chemosphere. 2010; 81(5):626-32. DOI: 10.1016/j.chemosphere.2010.03.043. View

Shahrokhi-Shahraki R, Benally C, Gamal El-Din M, Park J . High efficiency removal of heavy metals using tire-derived activated carbon vs commercial activated carbon: Insights into the adsorption mechanisms. Chemosphere. 2020; 264(Pt 1):128455. DOI: 10.1016/j.chemosphere.2020.128455. View

Wang L, Liu X, Lee D, Tay J, Zhang Y, Wan C . Recent advances on biosorption by aerobic granular sludge. J Hazard Mater. 2018; 357:253-270. DOI: 10.1016/j.jhazmat.2018.06.010. View

Wang X, Zhao Y, Yuan B, Wang Z, Li X, Ren Y . Comparison of biofouling mechanisms between cellulose triacetate (CTA) and thin-film composite (TFC) polyamide forward osmosis membranes in osmotic membrane bioreactors. Bioresour Technol. 2015; 202:50-8. DOI: 10.1016/j.biortech.2015.11.087. View

Hasani Zadeh P, G Fermoso F, Collins G, Serrano A, Mills S, Abram F . Impacts of metal stress on extracellular microbial products, and potential for selective metal recovery. Ecotoxicol Environ Saf. 2023; 252:114604. DOI: 10.1016/j.ecoenv.2023.114604. View

Vaiopoulou E, Gikas P . Regulations for chromium emissions to the aquatic environment in Europe and elsewhere. Chemosphere. 2020; 254:126876. DOI: 10.1016/j.chemosphere.2020.126876. View

Flemming H, Wingender J, Szewzyk U, Steinberg P, Rice S, Kjelleberg S . Biofilms: an emergent form of bacterial life. Nat Rev Microbiol. 2016; 14(9):563-75. DOI: 10.1038/nrmicro.2016.94. View

Hu Y, Zhou J, Du B, Liu H, Zhang W, Liang J . Health risks to local residents from the exposure of heavy metals around the largest copper smelter in China. Ecotoxicol Environ Saf. 2019; 171:329-336. DOI: 10.1016/j.ecoenv.2018.12.073. View

Li N, Liu J, Yang R, Wu L . Distribution, characteristics of extracellular polymeric substances of Phanerochaete chrysosporium under lead ion stress and the influence on Pb removal. Sci Rep. 2020; 10(1):17633. PMC: 7572388. DOI: 10.1038/s41598-020-74983-0. View

10.

Siddharth T, Sridhar P, Vinila V, Tyagi R . Environmental applications of microbial extracellular polymeric substance (EPS): A review. J Environ Manage. 2021; 287:112307. DOI: 10.1016/j.jenvman.2021.112307. View

11.

Li W, Yu H . Insight into the roles of microbial extracellular polymer substances in metal biosorption. Bioresour Technol. 2013; 160:15-23. DOI: 10.1016/j.biortech.2013.11.074. View

12.

Sheng G, Yu H, Li X . Extracellular polymeric substances (EPS) of microbial aggregates in biological wastewater treatment systems: a review. Biotechnol Adv. 2010; 28(6):882-94. DOI: 10.1016/j.biotechadv.2010.08.001. View

13.

Ajao V, Nam K, Chatzopoulos P, Spruijt E, Bruning H, Rijnaarts H . Regeneration and reuse of microbial extracellular polymers immobilised on a bed column for heavy metal recovery. Water Res. 2020; 171:115472. DOI: 10.1016/j.watres.2020.115472. View

14.

Sheng G, Yu H, Yue Z . Production of extracellular polymeric substances from Rhodopseudomonas acidophila in the presence of toxic substances. Appl Microbiol Biotechnol. 2005; 69(2):216-22. DOI: 10.1007/s00253-005-1990-6. View

15.

Wan C, Zhang P, Lee D, Yang X, Liu X, Sun S . Disintegration of aerobic granules: role of second messenger cyclic di-GMP. Bioresour Technol. 2013; 146:330-335. DOI: 10.1016/j.biortech.2013.07.073. View

16.

Tchounwou P, Yedjou C, Patlolla A, Sutton D . Heavy metal toxicity and the environment. Exp Suppl. 2012; 101:133-64. PMC: 4144270. DOI: 10.1007/978-3-7643-8340-4_6. View

17.

Thomas M, Kozik V, Bak A, Barbusinski K, Jazowiecka-Rakus J, Jampilek J . Removal of Heavy Metal Ions from Wastewaters: An Application of Sodium Trithiocarbonate and Wastewater Toxicity Assessment. Materials (Basel). 2021; 14(3). PMC: 7866974. DOI: 10.3390/ma14030655. View

18.

Wei L, Li J, Xue M, Wang S, Li Q, Qin K . Adsorption behaviors of Cu, Zn and Cd onto proteins, humic acid, and polysaccharides extracted from sludge EPS: Sorption properties and mechanisms. Bioresour Technol. 2019; 291:121868. DOI: 10.1016/j.biortech.2019.121868. View

19.

Lin Y, Reino C, Carrera J, Perez J, van Loosdrecht M . Glycosylated amyloid-like proteins in the structural extracellular polymers of aerobic granular sludge enriched with ammonium-oxidizing bacteria. Microbiologyopen. 2018; 7(6):e00616. PMC: 6291783. DOI: 10.1002/mbo3.616. View

20.

Jiang Y, Liu Y, Zhang H, Yang K, Li J, Shao S . Aerobic granular sludge shows enhanced resistances to the long-term toxicity of Cu(II). Chemosphere. 2020; 253:126664. DOI: 10.1016/j.chemosphere.2020.126664. View