Recovery of Phosphorus in Wastewater in the Form of Polyphosphates: A Review

As non-renewable resource, the recovery and utilization of phosphorus from wastewater is an enduring topic. Stimulated by the advances in research on polyphosphates (polyP) as well as the development of Enhanced Biological Phosphorus Removal (EBPR) technology to achieve the efficient accumulation of polyP via polyphosphate accumulating organisms (PAOs), a novel phosphorus removal strategy is considered with promising potential for application in real wastewater treatment processes. This review mainly focuses on the mechanism of phosphorus aggregation in the form of polyP during the phosphate removal process. Further discussion about the reuse of polyP with different chain lengths is provided herein so as to suggest possible application pathways for this biosynthetic product.

TbasCO: Trait-based Comparative ’Omics Identifies Ecosystem-Level and Niche- Differentiating Adaptations of an Engineered Microbiome

ABSTRACTA grand challenge in microbial ecology is disentangling the traits of individual populations within complex communities. Various cultivation-independent approaches have been used to infer traits based on the presence of marker genes. However, marker genes are not linked to traits with complete fidelity, nor do they capture important attributes, such as the timing of expression or coordination among traits. To address this, we present an approach for assessing the trait landscape of microbial communities by statistically defining a trait attribute as shared transcriptional pattern across multiple organisms. Leveraging the KEGG pathway database as a trait library and the Enhanced Biological Phosphorus Removal (EBPR) model microbial ecosystem, we demonstrate that a majority (65%) of traits present in 10 or more genomes have niche-differentiating expression attributes. For example, while 14 genomes containing the high-affinity phosphorus transporter pstABCS display a canonical attribute (e.g. up-regulation under phosphorus starvation), we identified another attribute shared by 11 genomes where transcription was highest under high phosphorus conditions. Taken together, we provide a novel framework for revealing hidden metabolic versatility when investigating genomic data alone by assigning trait-attributes through genome-resolved time-series metatranscriptomics.

On the issue of the feasibility of using modern technologies for biological phosphorus removal in low-capacity wastewater treatment plants

The article discusses the basic principles of wastewater treatment from biogenic elements, provides the necessary conditions for the biological removal of phosphorus compounds. The technology of pre-fermentation of the sediment of primary sedimentation tanks, options for its design, the main parameters of the process are described. Specific aspects of the operation of low-capacity wastewater treatment facilities are indicated and the expediency of using the technology of biological phosphorus removal in them is considered.

Modifying the resin type of hybrid anion exchange nanotechnology (HAIX-Nano) to improve its regeneration and phosphate recovery efficiency

In order to avoid eutrophication of freshwater systems, regulations all around the world have become increasingly stringent toward the maximum phosphate concentration allowed in wastewater discharges. Traditional phosphate removal methods such as chemical precipitation and enhanced biological phosphorus removal struggle to lower phosphate levels to the new requirements. Hybrid anion exchange nanotechnology (HAIX-Nano) is composed of a selective adsorption material able to remove phosphate down to levels close to zero. Moreover, HAIX-Nano is not affected by intermittent flow and does not produce sludge making it an interesting alternative. The regeneration process of HAIX-Nano typically requires a chemical solution with a high concentration of sodium hydroxide (NaOH) and sodium chloride (NaCl) (2–5% w/w of each). To lower the environmental impact and the operational cost of the technology, this study aims to enhance the HAIX-Nano regeneration efficiency. Therefore, the backbone of HAIX-Nano, which is normally a strong base anionic (SBA) resin, was changed for a weak base anionic (WBA) resin. The resulting material (WBA-2) exhibited a higher adsorption capacity than the traditional version of HAIX-Nano (SBA-1) under the tested conditions, while also showing a much higher regeneration efficiency. For a desorption solution of only 0.4% NaOH and no NaCl, WBA-2 showed an average regeneration efficiency of 78 ± 1% compared to SBA-1 with 24 ± 1%.

Perspectives of intracellular polymers in functional evaluation of the microbes for EBPR

To substantiate and interpret the performance of the Enhanced Biological Phosphorus Removal (EBPR) processes with simultaneous nitrogen removal in five full-scale sequencing batch reactors (SBR) systems (with or without pre-anoxic/anaerobic selector) across India, conventional microscopic examinations were performed. Regular examining and cyclic behavior evaluation studies specified that these systems worked for EBPR with effectiveness depending on the wastewater quality and operational steadiness. Treatment with Neisser stain for identifying polyphosphates (poly-P) and Sudan black B stain for observing poly-β-hydroxybutyrates (PHB) granules showed that the enriched biomass of the SBR plants was very diverse concerning morphology, residing populations of traditional rod-shaped PAOs, tetrad (or Sarcina-like cells) forming organisms (submitted as TFOs instead of GAOs), diplococci-shaped cells, and staphylococci-like clustered populations (CC), including few filaments which correlate well with biochemical processes undergoing in SBR plants. SBR plants with readily biodegradable chemical oxygen demand (rbCOD) fraction in COD > 16% and rbCOD/TP ∼10–20 in Varanasi, Mumbai, and Gurgaon, respectively, have performed for >20% EBPR (∼77.8%, ∼76.6%, and ∼84.8% TP removal, respectively) as well as >85% Simultaneous Nitrification and Denitrification (SND). This study can open novel dimensions for optimization by relating microscopic observations (qualitative examination) with the processes undergoing in the plants under varied physicochemical parameters.