On-Site Blackwater Treatment Fosters Microbial Groups and Functions to Efficiently and Robustly Recover Carbon and Nutrients.

Eiko E. Kuramae,Tania V. Fernandes,Adriano R. Lucheta,Mauricio R. Dimitrov,Lucas W. Mendes,Gustavo H. R. da Silva,Ronildson L. Luz,Louise E. M. Vet

doi:10.3390/microorganisms9010075

Eiko E. Kuramae, Tania V. Fernandes + Show 6 more

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https://doi.org/10.3390/microorganisms9010075

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Abstract

Wastewater is considered a renewable resource water and energy. An advantage of decentralized sanitation systems is the separation of the blackwater (BW) stream, contaminated with human pathogens, from the remaining household water. However, the composition and functions of the microbial community in BW are not known. In this study, we used shotgun metagenomics to assess the dynamics of microbial community structure and function throughout a new BW anaerobic digestion system installed at The Netherlands Institute of Ecology. Samples from the influent (BW), primary effluent (anaerobic digested BW), sludge and final effluent of the pilot upflow anaerobic sludge blanket (UASB) reactor and microalgae pilot tubular photobioreactor (PBR) were analyzed. Our results showed a decrease in microbial richness and diversity followed by a decrease in functional complexity and co-occurrence along the different modules of the bioreactor. The microbial diversity and function decrease were reflected both changes in substrate composition and wash conditions. Our wastewater treatment system also decreased microbial functions related to pathogenesis. In summary, the new sanitation system studied here fosters microbial groups and functions that allow the system to efficiently and robustly recover carbon and nutrients while reducing pathogenic groups, ultimately generating a final effluent safe for discharge and reuse.

Highlights

The global demand for freshwater is rising at a rate of approximately 1% per year due to population growth, changes in consumption patterns, and economic development [1].This increased demand comes as freshwater availability is decreasing due to climate change, unsustainable ground water consumption and other human activities [2]
dissolved oxygen (DO) was low in SP1, samples the reactor tor (SP-S) and SP2, indicating anaerobic conditions
The concentration of CODtotal in the BW in the present study is higher than that reported by Zeeman et al [5] and De Graaff et al [15] for BW collected from vacuum toilets, but the concentrations of Total nitrogen (TN) and total phosphorus (TP) are similar

Summary

Introduction

The global demand for freshwater is rising at a rate of approximately 1% per year due to population growth, changes in consumption patterns, and economic development [1]. This increased demand comes as freshwater availability is decreasing due to climate change, unsustainable ground water consumption and other human activities [2]. Due to this unsustainable impact on the global water cycle, a growing number of people are living under conditions of water scarcity and reduced water quality, endangering aquatic ecosystems and public health [1].

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