Impact of a Wastewater Treatment Plant Upgrade on Amphipods and Other Macroinvertebrates: Individual and Community Responses

Abstract

In the present study, we investigated the efficiency of additional wastewater treatment based on powdered activated carbon and its benefit for the ecosystem of a connected river system in the catchment area of Lake Constance, Southern Germany. We focused on the overall health status of gammarids and the integrity of the macrozoobenthic community. Samples were taken up-and downstream of a wastewater treatment plant (WWTP), as well as before and after its upgrading. The investigations showed that both sex ratio and fecundity of gammarids, as well as the macrozoobenthic community were affected by the effluent prior to the WWTP upgrade. After the upgrade, gammarids from the downstream site did not differ any longer from those collected upstream of the WWTP with respect to the investigated health parameters. Furthermore, the overall number of taxa and, particularly, the number of sensitive taxa within the macrozoobenthic community downstream of the WWTP increased considerably. Therefore, we conclude that the additional treatment with powdered activated carbon was highly efficient to improve invertebrate health and community integrity.

Freshwater ecosystems profit from activated carbon-based wastewater treatment across various levels of biological organisation in a short timeframe

“…The following results are described in more detail by Peschke et al [54]. Compared to reference sites upstream of the WWTP, a lower number of macrozoobenthic taxa were detected at site S2 prior to the WWTP upgrade (Fig.…”

“…A reduction in adverse effects after the installation of the additional treatment step was also observed in gammarids (details published by Peschke et al [54,57]). Prior to the installation of the additional treatment, a significantly reduced fecundity index of gammarids living at site S3 could be observed, whereas after the WWTP upgrade, fecundity indices at sites S0 and S3 were similar.…”

“…Saprobic index The results are described in more detail by Peschke et al [54]. Prior to the WWTP upgrade, a pronounced increase in the saprobic index could be detected at site S2 downstream of the effluent compared to the reference site S0 (Fig.…”

“…These results were corroborated by analysis of similarities (ANOSIM) for the entire community and for the sensitive taxa dataset. The comparison of the community structure prior vs. subsequent to the upgrade of the WWTP showed significant differences indicating a positive effect of the WWTP upgrade [54].…”

“…The respective methods used for the statistical analyses of method-specific data have been described elsewhere [25,27,30,32,35,37,43,47,54]. For the overall statistical analyses on which Figs.…”