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Ecological Applications : a Publication... Apr 2024Nitrogen (N) and phosphorus (P) are the two most important macronutrients supporting forest growth. Unprecedented urbanization has created growing areas of urban forests...
Nitrogen (N) and phosphorus (P) are the two most important macronutrients supporting forest growth. Unprecedented urbanization has created growing areas of urban forests that provide key ecosystem services for city dwellers. However, the large-scale patterns of soil N and P content remain poorly understood in urban forests. Based on a systematic soil survey in urban forests from nine large cities across eastern China, we examined the spatial patterns and key drivers of topsoil (0-20 cm) total N content, total P content, and N:P ratio. Topsoil total N content was found to change significantly with latitude in the form of an inverted parabolic curve, while total P content showed an opposite latitudinal pattern. Variance partition analysis indicated that regional-scale patterns of topsoil total N and P contents were dominated by climatic drivers and partially regulated by time and pedogenic drivers. Conditional regression analyses showed a significant increase in topsoil total N content with lower mean annual temperature (MAT) and higher mean annual precipitation (MAP), while topsoil total P content decreased significantly with higher MAP. Topsoil total N content also increased significantly with the age of urban park and varied with pre-urban soil type, while no such effects were found for topsoil total P content. Moreover, topsoil N:P ratio showed a latitudinal pattern similar to that of topsoil total N content and also increased significantly with lower MAT and higher MAP. Our findings demonstrate distinct latitudinal trends of topsoil N and P contents and highlight a dominant role of climatic drivers in shaping the large-scale patterns of topsoil nutrients in urban forests.
Topics: Ecosystem; Phosphorus; Nitrogen; Carbon; Forests; China; Soil
PubMed: 38357775
DOI: 10.1002/eap.2951 -
Waste Management (New York, N.Y.) Aug 2023The work studies the recovery of nutrients (phosphorus and nitrogen) from the process water of acid-assisted hydrothermal carbonization (HTC) of cow manure. Three...
The work studies the recovery of nutrients (phosphorus and nitrogen) from the process water of acid-assisted hydrothermal carbonization (HTC) of cow manure. Three organic acids (formic acid, oxalic acid, and citric acid) and sulfuric acid were evaluated as additives in HTC. Using 0.3 M sulfuric acid, more than 99% of phosphorus and 15.6% of nitrogen from manure are extracted and dissolved during HTC at 170 °C with 10 min reaction time in a batch reactor. Nutrients (mainly phosphorus) were recovered through precipitation from process water by raising the ionic strength of the solution by addition of salts of magnesium and ammonia, and by raising the pH to 9.5. Subsequently, phosphorus-rich solids were recovered containing almost all (greater than 95%) of the dissolved phosphorus in the sulfuric and formic acid assisted runs. Morphology and qualitative chemical analysis of the precipitates were determined. It is shown by XRD that the precipitate formed from process water generated by HTC with oxalic acid is crystalline, although the diffraction pattern could not be matched with any expected substance.
Topics: Animals; Female; Cattle; Phosphorus; Manure; Water; Nitrogen; Sulfuric Acids; Carbon; Temperature
PubMed: 37331265
DOI: 10.1016/j.wasman.2023.06.013 -
Scientific Reports Oct 2023Although ground-baiting related nutrient loading has been widely studied, we do not know what proportion of these nutrients release into the water column, affecting...
Although ground-baiting related nutrient loading has been widely studied, we do not know what proportion of these nutrients release into the water column, affecting primary production directly. We conducted short-term (24-h, 5-day) experiments at wide temperature range, in presence and absence of fish using fish meal-based (FM-GB) and plant-based groundbait (PB-GB), to assess the nitrogen (N) and phosphorus (P) fluxes from GB into the water column. Nitrogen release from unconsumed FM-GB was negligible in the first 3 days, then increased abruptly, releasing 32% of its total N content by the fifth day. In contrast, PB-GB acted as temporary sink for inorganic N forms. Considerable (18-21%) inorganic P release was observed in both GB types in the first twelve hours. Consumed GBs induced considerable inorganic N release and its rate increased with temperature. Particulate forms predominated the released N in PB-GB, suggesting impaired digestion. Phosphorus-dominated by particulate forms-release was similar or lower than in unconsumed GB. Based on our results, excessive use of GB-when high amount of it remains unconsumed-can enhance eutrophication in P-limited ecosystems. Although less digestible GBs may have less abrupt effect on the primary production, undigested nutrients remain unavailable for removal through fish harvest.
Topics: Animals; Water; Ecosystem; Phosphorus; Water Pollutants, Chemical; Nutrients; Nitrogen; Eutrophication; Environmental Monitoring
PubMed: 37848478
DOI: 10.1038/s41598-023-44381-3 -
The Science of the Total Environment Oct 2023Blooms of blue-green algae (BGA) threaten drinking water safety and ecosystems worldwide. Understanding mechanisms and driving factors that promote BGA proliferation is...
Blooms of blue-green algae (BGA) threaten drinking water safety and ecosystems worldwide. Understanding mechanisms and driving factors that promote BGA proliferation is crucial for effective freshwater management. This study tested the response of BGA growth to environmental variations driven by nutrients (N and P), N:P ratios, and flow regime depending on the influence of the Asian monsoon intensity and identified the critical regulatory factors in a temperate drinking-water reservoir, using weekly interval samplings collected during 2017-2022. The hydrodynamic and underwater light conditions experienced significant changes in summers due to high inflows and outflows associated with intense rainfalls, and these conditions strongly influenced the proliferation of BGA and total phytoplankton biomass (as estimated by chlorophyll-a [CHL-a]) during summer monsoons. However, the intense monsoon resulted in the post-monsoon blooms of BGA. The monsoon-induced phosphorus enrichment, facilitated through soil washing and runoff, was crucial in promoting phytoplankton blooms in early post-monsoon (September). Thus, the monomodal phytoplankton peak was evident in the system, compared to the bimodal peaks in North American and European lakes. Strong water column stability in the weak monsoon years depressed phytoplankton growth and BGA, suggesting the importance of the intensity of monsoon. The low N:P ratios and longer water residence time increased BGA abundance. The predictive model of BGA abundance accounted for the variations largely (Mallows' C = 0.39, adjusted R = 0.55, p < 0.001) by dissolved phosphorus, N:P ratios, CHL-a, and inflow volume. Overall, this study suggests that monsoon intensity was the key triggering factor regulating the interannual BGA variations and facilitated the post-monsoon blooms through increased nutrient availability.
Topics: Drinking Water; Seasons; Ecosystem; Cyanobacteria; Chlorophyll; Phytoplankton; Lakes; Phosphorus; Eutrophication
PubMed: 37419340
DOI: 10.1016/j.scitotenv.2023.165306 -
Water Environment Research : a Research... Mar 2024Eutrophication, the over-enrichment with nutrients, for example, nitrogen and phosphorus, of ponds, reservoirs and lakes, is an urgent water quality issue. The most... (Review)
Review
Eutrophication, the over-enrichment with nutrients, for example, nitrogen and phosphorus, of ponds, reservoirs and lakes, is an urgent water quality issue. The most notorious symptom of eutrophication is a massive proliferation of cyanobacteria, which cause aquatic organism death, impair ecosystem and harm human health. The method considered to be most effective to counteract eutrophication is to reduce external nutrient inputs. However, merely controlling external nutrient load is insufficient to mitigate eutrophication. Consequently, a rapid diminishing of cyanobacterial blooms is relied on in-lake intervention, which may encompass a great variety of different approaches. Coagulation/flocculation is the most used and important water purification unit. Since cyanobacterial cells generally carry negative charges, coagulants are added to water to neutralize the negative charges on the surface of cyanobacteria, causing them to destabilize and precipitate. Most of cyanobacteria and their metabolites can be removed simultaneously. However, when cyanobacterial density is high, sticky secretions distribute outside cells because of the small size of cyanobacteria. The sticky secretions are easily to form complex colloids with coagulants, making it difficult for cyanobacteria to destabilize and resulting in unsatisfactory treatment effects of coagulation on cyanobacteria. Therefore, various coagulants and coagulation methods were developed. In this paper, the focus is on the coagulation of cyanobacteria as a promising tool to manage eutrophication. Basic principles, applications, pros and cons of chemical, physical and biological coagulation are reviewed. In addition, the application of coagulation in water treatment is discussed. It is the aim of this review article to provide a significant reference for large-scale governance of cyanobacterial blooms. PRACTITIONER POINTS: Flocculation was a promising tool for controlling cyanobacteria blooms. Basic principles of four kinds of flocculation methods were elucidated. Flocculant was important in the flocculation process.
Topics: Humans; Ecosystem; Cyanobacteria; Water Quality; Lakes; Ponds; Eutrophication; Phosphorus
PubMed: 38403998
DOI: 10.1002/wer.11002 -
Environmental Science & Technology Jul 2024Phosphorus (P) limitation often constrains biological processes in Arctic tundra ecosystems. Although adsorption to soil minerals may limit P bioavailability and export...
Phosphorus (P) limitation often constrains biological processes in Arctic tundra ecosystems. Although adsorption to soil minerals may limit P bioavailability and export from soils into aquatic systems, the contribution of mineral phases to P retention in Arctic tundra is poorly understood. Our objective was to use X-ray absorption spectroscopy to characterize P speciation and associations with soil minerals along hillslope toposequences and in undisturbed and disturbed low-lying wet sedge tundra on the North Slope, AK. Biogenic mats comprised of short-range ordered iron (Fe) oxyhydroxides were prevalent in undisturbed wet sedge meadows. Upland soils and pond sediments impacted by gravel mining or thermokarst lacked biogenic Fe mats and were comparatively iron poor. Phosphorus was primarily contained in organic compounds in hillslope soils but associated with Fe(III) oxyhydroxides in undisturbed wet sedge meadows and calcium (Ca) in disturbed pond sediments. We infer that phosphate mobilized through organic decomposition binds to Fe(III) oxyhydroxides in wet sedge, but these associations are disrupted by physical disturbance that removes Fe mats. Increasing disturbances of the Arctic tundra may continue to alter the mineralogical composition of soils at terrestrial-aquatic interfaces and binding mechanisms that could inhibit or promote transport of bioavailable P from soils to aquatic ecosystems.
Topics: Phosphorus; Arctic Regions; Iron; Tundra; Ecosystem; X-Ray Absorption Spectroscopy; Soil; Geologic Sediments
PubMed: 38889135
DOI: 10.1021/acs.est.3c09072 -
The Science of the Total Environment Jul 2023Due to the phosphorus (P) deficiency in coking wastewater, sufficient P needs to be provided in the treatment process to maintain biotic activity. However, most of the...
Due to the phosphorus (P) deficiency in coking wastewater, sufficient P needs to be provided in the treatment process to maintain biotic activity. However, most of the dosed P sources are transferred to the sludge phase out of the chemical equilibrium. After an in-depth investigation of P morphology changes in coking wastewater treatment, it is found that above 71.6 % P applied to the full-scale O/H/H/O (oxic-hydrolytic & denitrification-hydrolytic & denitrification-oxic) process for coking wastewater treatment is ended up in the sludge phase of the aerobic reactors in the forms of non-apatite inorganic phosphorus (NAIP). Theoretical simulations suggest that the P forms precipitates such as FePO·2HO, AlPO·2HO, MnHPO at pH < 7, and Ca(PO)OH at pH > 7. Microbial utilization of P in coking wastewater treatment is swayed by precipitation, pH and sludge retention time (SRT). By pyrolysis treatment of the waste sludge at 700 °C, phosphoric substances in coking sludge are enriched and converted into Ca(PO)OH, Ca(PO)Cl, Ca(PO), etc. with apatite phosphorus (AP) accounting for 65.7 % of total phosphorus. Moreover, the heavy metals in biochar were below the national standard limits for discharge. This study shows that hazardous waste (coking sludge) can be transformed into bioavailable products (P-rich biochar) through comprehensive management of the fate of P. Combined with the O/H/H/O process, the mechanisms of phosphorus consumption in coking wastewater treatment are revealed for the first time, which will facilitate a reduced consumption of phosphorus and provide a demonstration for other phosphorus-deficient industrial wastewater treatment.
Topics: Wastewater; Sewage; Phosphorus; Coke
PubMed: 37044344
DOI: 10.1016/j.scitotenv.2023.163384 -
Environmental Science & Technology Jun 2024The feasibility of a synergistic endogenous partial denitrification-phosphorus removal coupled anammox (SEPD-PR/A) system was investigated in a modified anaerobic...
The feasibility of a synergistic endogenous partial denitrification-phosphorus removal coupled anammox (SEPD-PR/A) system was investigated in a modified anaerobic baffled reactor (mABR) for synchronous carbon, nitrogen, and phosphorus removal. The mABR comprising four identical compartments (i.e., C1-C4) was inoculated with precultured denitrifying glycogen-accumulating organisms (DGAOs), denitrifying polyphosphate-accumulating organisms, and anammox bacteria. After 136 days of operation, the chemical oxygen demand (COD), total nitrogen, and phosphorus removal efficiencies reached 88.6 ± 1.0, 97.2 ± 1.5, and 89.1 ± 4.2%, respectively. Network-based analysis revealed that the biofilmed community demonstrated stable nutrient removal performance under oligotrophic conditions in C4. The metagenome-assembled genomes (MAGs) such as MAG106, MAG127, MAG52, and MAG37 annotated as denitrifying phosphorus-accumulating organisms (DPAOs) and MAG146 as a DGAO were dominated in C1 and C2 and contributed to 89.2% of COD consumption. MAG54 and MAG16 annotated as (total relative abundance of 16.5% in C3 and 4.3% in C4) were responsible for 74.4% of the total nitrogen removal through the anammox-mediated pathway. Functional gene analysis based on metagenomic sequencing confirmed that different compartments of the mABR were capable of performing distinct functions with specific advantageous microbial groups, facilitating targeted nutrient removal. Additionally, under oligotrophic conditions, the activity of the anammox bacteria-related genes of was higher compared to that of . Thus, an innovative method for the treatment of low-strength municipal and nitrate-containing wastewaters without aeration was presented, mediated by an anammox process with less land area and excellent quality effluent.
Topics: Phosphorus; Denitrification; Nitrogen; Carbon; Bioreactors; Bacteria
PubMed: 38817146
DOI: 10.1021/acs.est.4c00558 -
Journal of Environmental Management Oct 2023Analysing the vertical distribution of nutrient salts and estimating the total mass of lake nutrients is helpful for the management of lake nutrient status and the...
Analysing the vertical distribution of nutrient salts and estimating the total mass of lake nutrients is helpful for the management of lake nutrient status and the formulation of drainage standards in basins. However, studies on nitrogen (N) and phosphorus (P) in lakes have focused on obtaining measures of N and P concentrations, but no understanding exists on the vertical distribution of N and P in the entire water column. The present study proposes algorithms for estimating the total masses of N/P per unit water column (ALGO-TN/ALGO-TP) for shallow eutrophic lakes. Using Lake Taihu as an example, the total masses of nutrients in Lake Taihu in the historical period were obtained, and the algorithm performance was discussed. The results showed that the vertical distribution of nutrients decreased with increasing depth and exhibited a quadratic distribution. Surface nutrients and chlorophyll-a concentrations play important roles in the vertical distribution of nutrients. Based on conventional surface water quality indicators, algorithms for the vertical nutrient concentration in Lake Taihu were proposed. Both algorithms had good accuracy (ALGO-TN R > 0.75, RMSE <0.57; ALGO-TP R > 0.80, RMSE ≤0.50), the ALGO-TP had better applicability than the ALGO-TN, and had good accuracy in other shallow lakes. Therefore, deducing the TP using conventional water quality indicators in surface water, which not only simplifies the sampling process but also provides an opportunity for remote sensing technology to monitor the total masses of nutrients, is feasible. The long-term average total mass of N was 11,727 t, showing a gradual downward trend before 2010, after which it stabilised. The maximum and minimum intra-annual total N masses were observed in May and November, respectively. The long-term average total mass of P was 512 t, showing a gradual downward trend before 2010, and a slow upward trend thereafter. The maximum and minimum intra-annual total masses of P occurred in August and February or May, respectively. The correlation between the total mass of N and meteorological conditions was not obvious, whereas some influence on the total mass of P was evident, particularly water level and wind speed.
Topics: Lakes; Environmental Monitoring; Nitrogen; Phosphorus; Water Quality; China; Eutrophication
PubMed: 37418911
DOI: 10.1016/j.jenvman.2023.118465 -
Tree Physiology Feb 2024In the context of the resource allocation hypothesis regarding the trade-off between growth and defence, compared with native species, invasive species generally...
In the context of the resource allocation hypothesis regarding the trade-off between growth and defence, compared with native species, invasive species generally allocate more energy to growth and less energy to defence. However, it remains unclear how global change and nutrient enrichment will influence the competition between invasive species and co-occurring native species. Here, we tested whether nitrogen (N) and phosphorus (P) addition under elevated CO2 causes invasive species (Mikania micrantha and Chromolaena odorata) to produce greater biomass, higher growth-related compounds and lower defence-related compounds than native plants (Paederia scandens and Eupatorium chinense). We grew these native and invasive species with similar morphology with the addition of N and P under elevated CO2 in open-top chambers. The addition of N alone increased the relative growth rate (RGR) by 5.4% in invasive species, and its combination with P addition or elevated CO2 significantly increased the RGR of invasive species by 7.5 or 8.1%, respectively, and to a level higher than that of native species (by 14.4%, P < 0.01). Combined N + P addition under elevated CO2 decreased the amount of defence-related compounds in the leaf, including lipids (by 17.7%) and total structural carbohydrates (by 29.0%), whereas it increased the growth-related compounds in the leaf, including proteins (by 75.7%), minerals (by 9.6%) and total non-structural carbohydrates (by 8.5%). The increased concentrations of growth-related compounds were possibly associated with the increase in ribulose 1,5-bisphosphate carboxylase oxygenase content and mineral nutrition (magnesium, iron and calcium), all of which were higher in the invasive species than in the native species. These results suggest that rising atmospheric CO2 concentration and N deposition combined with nutrient enrichment will increase the growth of invasive species more than that of native species. Our result also suggests that invasive species respond more readily to produce growth-related compounds under an increased soil nutrient availability and elevated CO2.
Topics: Introduced Species; Carbon Dioxide; Phosphorus; Nitrogen; Nutrients; Carbohydrates
PubMed: 38102760
DOI: 10.1093/treephys/tpad150