Critical review of the influences of nanoparticles on biological wastewater treatment and sludge digestion

Abstract

Nanoparticles (NPs), with at least one dimension less than 100 nm, are substantially employed in consumer and industrial products due to their specific physical and chemical properties. The wide uses of engineered NPs inevitably cause their release into the environment, especially wastewater treatment plants. Therefore, it is essential to systematically assess their potential impact on biological wastewater treatment and subsequent sewage sludge digestion. This review aims to provide such support. First, this paper reviews the recent advances on the analytical developments and nano-bio interface of NPs in wastewater and sewage sludge treatment. The effects of NPs on biological wastewater treatment and sewage sludge digestion and related mechanisms are discussed in detail. Finally, the key questions that need to be answered in the future are pointed out, which include on-line revelation of the changes of NPs in sewage and sludge environments, in situ assessment of the variations of microorganisms involved in these biological systems after they are exposed to NPs. Differentiation of the contribution of individual toxicity mechanisms to these systems, and the identification of under what conditions the nanoparticle-induced toxicity will be increased or decreased are also considered.

Fe2+ Alleviated the Toxicity of ZnO Nanoparticles to Pseudomonas tolaasii Y-11 by Changing Nanoparticles Behavior in Solution

“…Zhang et al [15] found that the accumulation of toxic Zn 2+ in organisms resulted in the loss of 90% nitrogen removal capacity due to ZnO-NPs shock. In addition, ZnO-NPs are easily adsorbed on the surface of bacteria and can permeate into cells causing toxic effects [16]. Therefore, it is of great significance to clarify the toxicity source of ZnO-NPs in order to study and alleviate their toxicity.…”

Silver nanoparticle filter for domestic wastewater reuse

“…Similar results were reported using cellulose blotting sheets doped with AgNPs to purify drinking water with a log decay of 6 and 3 for E. coli and E. faecalis, respectively. 30 Similarly, AgNPs adsorbed on a film made of weak electrolytes cross-linked with glutaraldehyde showed a reduction of 93% coliforms in industrial wastewater after 60 h of treatment. 9 The interaction of AgNPs with E. coli observed by TEM showed the attachment of the nanoparticles to the outer membrane, followed by cell internalization and bacterial lysis.…”

Exogenous Fe2+ alleviated the toxicity of CuO nanoparticles on Pseudomonas tolaasii Y-11 under different nitrogen sources

“…Low-dose CuO-NPs (1 mg/L) released less than 0.1 mg/L Cu 2+ ( Fig. 2A ), which may be the main reason for the low dose of CuO-NPs (<1 mg/L) induced the synthesis of related enzymes (such as Cu-containing nitrite reductase) and material transfer to increase the activity of the bacteria ( Huang et al, 2020 ; Wang & Chen, 2016 ; Zhang et al, 2017a ). The addition of Fe 2+ promoted the release of Cu 2+ .…”