An official website of the United States government
Abstract Enhanced biological phosphorus removal (EBPR) can recover significant quantities of wastewater phosphorus. However, this resource recovery process realizes limited use largely due to process stability concerns. The research evaluated the effects of anaerobic HRT (τAN) and VFA concentration—critical operational parameters that can be externally controlled—on EBPR performance. Evaluated alone, τAN(1–4 h) exhibited no statistical effect on effluent phosphorus. However, PHA increased with VFA loading and biomass accumulated more phosphorus. Regarding resiliency, under increasing VFA loads PAOs hydrolyzed more phosphorus to uptake/catabolize VFAs; moreover, PHA synthesis normalized to VFA loading increased with τAN, suggesting fermentation. Kinetically, PAOs exhibited a Monod‐like relationships for qPHAANand qVFAANas a function of anaerobic P release; additionally, qPAEexhibited a Monod‐like relationship with end‐anaerobic PHA concentration. A culminating analysis affirmed the relationship between enhanced aerobic P uptake, and net P removal, with a parameter (phosphorus removal propensity factor) that combines influent VFA concentration with τAN. Practitioner pointsEvaluated alone τANexhibits no statistical effect on effluent phosphorus in an EBPR configuration.Increased PHA synthesis, associated with increased VFAs and/or extended τAN,enhances aerobic phosphorus removal.PHA synthesis normalized to VFA loading increased with τAN, suggesting fermentation in the EBPR anaerobic zone.Aerobic phosphorus uptake increases linearly with anaerobic phosphorus release, with the slope exceeding unity.Increased VFAs can be substituted for shorter anaerobic HRTs, and vice versa, to enhance EBPR performance.
more »
« less
This content will become publicly available on January 21, 2026
An electrospray-active N-heterocyclic carbene ligand for real-time analysis of organometallic reactions
An N-heterocyclic carbene containing a pendant triphenylphosphonium group is an excellent new charge-tagged ligand for mass spectrometry.
more »
« less
- Award ID(s):
- 2214606
- PAR ID:
- 10629632
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Dalton Transactions
- Volume:
- 54
- Issue:
- 4
- ISSN:
- 1477-9226
- Page Range / eLocation ID:
- 1365 to 1369
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Bojanczyk, Mikolaj; Chekuri, Chandra (Ed.)Given a point set P in the plane, we seek a subset Q ⊆ P, whose convex hull gives a smaller and thus simpler representation of the convex hull of P. Specifically, let cost(Q,P) denote the Hausdorff distance between the convex hulls CH(Q) and CH(P). Then given a value ε > 0 we seek the smallest subset Q ⊆ P such that cost(Q,P) ≤ ε. We also consider the dual version, where given an integer k, we seek the subset Q ⊆ P which minimizes cost(Q,P), such that |Q| ≤ k. For these problems, when P is in convex position, we respectively give an O(n log²n) time algorithm and an O(n log³n) time algorithm, where the latter running time holds with high probability. When there is no restriction on P, we show the problem can be reduced to APSP in an unweighted directed graph, yielding an O(n^2.5302) time algorithm when minimizing k and an O(min{n^2.5302, kn^2.376}) time algorithm when minimizing ε, using prior results for APSP. Finally, we show our near linear algorithms for convex position give 2-approximations for the general case.more » « less
-
Abstract Background and objectivesThe coproduct of ethanol industry, dried distiller's grains with solubles (DDGS), has phosphorus content in excess of the animal diet requirement, which leads to excess P in manure and causes environmental concerns. The objective of this study is to determine the technical and economic feasibility of recovering this excess P as a coproduct. FindingsThe amount of P was observed to reduce from 9.26 to 3.25 mg/g (db) of DDGS, which is consistent with the animal diet requirement of 3–4 mg P/g animal diet. For an existing dry grind plant of 40 million gallon ethanol capacity, an additional fixed cost of $5.7 million was estimated, with an operating cost increase of $1.29 million/year. ConclusionsThe total phosphorus recovered from the plant was estimated as 1,676 kg P/day, with an estimated operating cost of $2.33/kg P recovered. Significance and noveltyApproximately 37 million MT of DDGS is produced annually as animal food containing excess P, which is a serious concern for the environment. This study provides with an economically feasible solution to recover the excess P as a coproduct, which has a potential to be used as fertilizer on more than 56,000 acres of land annually, growing corn and soybean.more » « less
-
For $$1<\infty$$, we emulate the Bergman projection on Reinhardt domains by using a Banach-space basis of $L^p$-Bergman space. The construction gives an integral kernel generalizing the ($L^2$) Bergman kernel. The operator defined by the kernel is shown to be an absolutely bounded projection on the $L^p$-Bergman space on a class of domains where the $L^p$-boundedness of the Bergman projection fails for certain $$p \neq 2$$. As an application, we identify the duals of these $L^p$-Bergman spaces with weighted Bergman spaces.more » « less
-
Abstract Let $$E$$ be an elliptic curve defined over $${\mathbb{Q}}$$ of conductor $$N$$, $$p$$ an odd prime of good ordinary reduction such that $E[p]$ is an irreducible Galois module, and $$K$$ an imaginary quadratic field with all primes dividing $Np$ split. We prove Iwasawa main conjectures for the $${\mathbb{Z}}_{p}$$-cyclotomic and $${\mathbb{Z}}_{p}$$-anticyclotomic deformations of $$E$$ over $${\mathbb{Q}}$$ and $K,$ respectively, dispensing with any of the ramification hypotheses on $E[p]$ in previous works. The strategy employs base change and the two-variable zeta element associated to $$E$$ over $$K$$, via which the sought after main conjectures are deduced from Wan’s divisibility towards a three-variable main conjecture for $$E$$ over a quartic CM field containing $$K$$ and certain Euler system divisibilities. As an application, we prove cases of the two-variable main conjecture for $$E$$ over $$K$$. The aforementioned one-variable main conjectures imply the $$p$$-part of the conjectural Birch and Swinnerton-Dyer formula for $$E$$ if $$\operatorname{ord}_{s=1}L(E,s)\leq 1$$. They are also an ingredient in the proof of Kolyvagin’s conjecture and its cyclotomic variant in our joint work with Grossi [1].more » « less
