Nitrate removal from reverse osmosis concentrate in pilot-scale open-water unit process wetlands

Scholes, Rachel C.; Vega, Michael; Sharp, Jonathan O.; Sedlak, David L.

doi:10.1039/d0ew00911c

Cited by 29 publications

(46 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The faster removal observed in 2019 was consistent with greater biomat activity in 2019 compared to 2018, which was supported by observations of greater biomat depth and nitrate removal capacity in 2019. 31 As predicted, removal rates declined during the cooler, winter months.…”

Section: Phototransformationmentioning

confidence: 55%

“…31 Notably, although pH and dissolved oxygen profiles indicated strong photosynthetic activity within one month of startup, the biomat microbial community evolved throughout the first 18 months of operation and greater nitrate removal in the biomat was observed in summer 2019 compared to summer 2018. 31 Removal of atenolol and metoprolol was consistent with predictions from biotransformation models developed for open-water wetlands treating wastewater effluent (Figure 2). 29 During the summer 2018, calculated rate constants in the cell without ozone pre-treatment (Cell 1) averaged 0.50 d -1 and 0.48 d -1 for atenolol and metoprolol, respectively, which were similar to the predicted rate constants of 0.57 d -1 and 0.43 d -1 .…”

Section: Phototransformationmentioning

confidence: 96%

“…The pilot-scale ozone/wetland system was operated between July 2017 and September 2019, as described elsewhere. 31 The system consisted of two shallow (30 cm deep) parallel open-water treatment wetland cells lined with an impermeable liner. The surface area of each wetland was approximately 200 m 2 .…”

Section: Pilot Treatment Systemmentioning

confidence: 99%

“…We hypothesized that the combination of removal mechanisms would provide a robust barrier for a broad suite of organic contaminants in the wetland while simultaneously removing contaminants that are not affected by ozonation (e.g., nitrate). 31 Furthermore, we hypothesized that the biological activity in open-water wetlands could serve as an effective alternative to biological activated carbon or sand filtration for removing compounds that are susceptible to biotransformation. We tested these hypotheses by combining the analysis of surrogate compounds indicative of photo-and bio-transformation removal mechanisms with analysis of urban-use pesticides that have been identified by experts as concerns for the San Francisco Bay.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Transformation of Trace Organic Contaminants from Reverse Osmosis Concentrate by Open-Water Unit-Process Wetlands with and without Ozone Pretreatment

Scholes

King²,

Mitch³

et al. 2020

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Reverse osmosis (RO) treatment of municipal wastewater effluent is becoming more common as water reuse is implemented in water-stressed regions. Where RO concentrate is discharged with limited dilution, concentrations of trace organic contaminants could pose risks to aquatic ecosystems. To provide a low-cost option for removing trace organic compounds from RO concentrate, a pilot-scale treatment system comprised of open-water unit process wetlands with and without ozone pre-treatment was studied over a two-year period. A suite of ecotoxicologically-relevant organic contaminants was partially removed via photo-and bio-transformation, including b-adrenergic blockers, antivirals, an antibiotic, and pesticides. Biotransformation rates were as fast or up to approximately 50% faster than model predictions based upon data from open-water wetlands that treated municipal wastewater effluent. Phototransformation rates were comparable to or as much as 60% slower than predicted by models that accounted for light penetration and scavenging of reactive oxygen species. Several compounds were transformed during ozone pre-treatment that were poorly removed in the open-water wetland. The combined treatment system resulted in a decrease in the risk quotients of trace organic contaminants in RO concentrate, but dilution still may be required to protect sensitive species from urban-use pesticides with low environmental effect concentrations.

show abstract

Section: Phototransformationmentioning

confidence: 55%

Section: Phototransformationmentioning

confidence: 96%

Section: Pilot Treatment Systemmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Transformation of Trace Organic Contaminants from Reverse Osmosis Concentrate by Open-Water Unit-Process Wetlands with and without Ozone Pretreatment

Scholes

King²,

Mitch³

et al. 2020

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thus, removing these P-containing organophosphonate compounds from ROC before its further treatment or discharge is imperative [26]. Scholes et al [27] revealed that open-water wetlands can remove nitrate from RO concentrate at the pilot scale and identified opportunities to enhance treatment efficiency with low-cost carbon amendments.…”

Section: Introductionmentioning

confidence: 99%

Reverse Osmosis Concentrate: Physicochemical Characteristics, Environmental Impact, and Technologies

et al. 2021

View full text Add to dashboard Cite

This study’s aim is to generate a complete profile of reverse osmosis concentrate (ROC), including physicochemical characteristics, environmental impact, and technologies for ROC treatment, alongside element recovery with potential valorization. A systematic literature review was used to compile and analyze scientific information about ROC, and systematic identification and evaluation of the data/evidence in the articles were conducted using the methodological principles of grounded data theory. The literature analysis revealed that two actions are imperative: (1) countries should impose strict regulations to avoid the contamination of receiving water bodies and (2) desalination plants should apply circular economies. Currently, synergizing conventional and emerging technologies is the most efficient method to mitigate the environmental impact of desalination processes. However, constructed wetlands are an emerging technology that promise to be a viable multi-benefit solution, as they can provide simultaneous treatment of nutrients, metals, and trace organic contaminants at a relatively low cost, and are socially accepted; therefore, they are a sustainable solution.

show abstract

Supramolecular Enhancement of Electrochemical Nitrate Reduction Catalyzed by Cobalt Porphyrin Organic Cages for Ammonia Electrosynthesis in Water**

Narouz

Smith

et al. 2023

Angewandte Chemie

View full text Add to dashboard Cite

The electrochemical nitrate (NO3−) reduction reaction (NO3RR) to ammonia (NH3) represents a sustainable approach for denitrification to balance global nitrogen cycles and an alternative to traditional thermal Haber‐Bosch processes. Here, we present a supramolecular strategy for promoting NH3 production in water from NO3RR by integrating two‐dimensional (2D) molecular cobalt porphyrin (CoTPP) units into a three‐dimensional (3D) porous organic cage architecture. The porphyrin box CoPB‐C8 enhances electrochemical active site exposure, facilitates substrate–catalyst interactions, and improves catalyst stability, leading to turnover numbers and frequencies for NH3 production exceeding 200,000 and 56 s−1, respectively. These values represent a 15‐fold increase in NO3RR activity and 200‐mV improvement in overpotential for the 3D CoPB‐C8 box structure compared to its 2D CoTPP counterpart. Synthetic tuning of peripheral alkyl substituents highlights the importance of supramolecular porosity and cavity size on electrochemical NO3RR activity. These findings establish the incorporation of 2D molecular units into 3D confined space microenvironments as an effective supramolecular design strategy for enhancing electrocatalysis.

show abstract

Nitrate removal from reverse osmosis concentrate in pilot-scale open-water unit process wetlands

Abstract: Biological treatment of nitrate in reverse osmosis (RO) concentrate produced from municipal wastewater effluent is challenging, in part because of the low carbon-to-nitrogen ratio. Open-water unit process wetlands may provide...

Cited by 29 publications

References 43 publications

Transformation of Trace Organic Contaminants from Reverse Osmosis Concentrate by Open-Water Unit-Process Wetlands with and without Ozone Pretreatment

Transformation of Trace Organic Contaminants from Reverse Osmosis Concentrate by Open-Water Unit-Process Wetlands with and without Ozone Pretreatment

Reverse Osmosis Concentrate: Physicochemical Characteristics, Environmental Impact, and Technologies

Supramolecular Enhancement of Electrochemical Nitrate Reduction Catalyzed by Cobalt Porphyrin Organic Cages for Ammonia Electrosynthesis in Water**

Contact Info

Product

Resources

About