Organic acid regulation of inorganic phosphorus release from Mollisols with different organic matter contents

2021 ◽  
Author(s):  
Xiaoyan Yang ◽  
Yuhua Kong ◽  
Erhui Guo ◽  
Xiangwei Chen ◽  
Limei Li
2021 ◽  
Vol 18 (9) ◽  
pp. 2981-3004
Author(s):  
Astrid Hylén ◽  
Sebastiaan J. van de Velde ◽  
Mikhail Kononets ◽  
Mingyue Luo ◽  
Elin Almroth-Rosell ◽  
...  

Abstract. Phosphorus fertilisation (eutrophication) is expanding oxygen depletion in coastal systems worldwide. Under low-oxygen bottom water conditions, phosphorus release from the sediment is elevated, which further stimulates primary production. It is commonly assumed that re-oxygenation could break this “vicious cycle” by increasing the sedimentary phosphorus retention. Recently, a deep-water inflow into the Baltic Sea created a natural in situ experiment that allowed us to investigate if temporary re-oxygenation stimulates sedimentary retention of dissolved inorganic phosphorus (DIP). Surprisingly, during this 3-year study, we observed a transient but considerable increase, rather than a decrease, in the sediment efflux of DIP and other dissolved biogenic compounds. This suggested that the oxygenated inflow elevated the organic matter degradation in the sediment, likely due to an increase in organic matter supply to the deeper basins, potentially combined with a transient stimulation of the mineralisation efficiency. As a result, the net sedimentary DIP release per m2 was 56 %–112 % higher over the years following the re-oxygenation than before. In contrast to previous assumptions, our results show that inflows of oxygenated water to anoxic bottom waters can increase the sedimentary phosphorus release.


2020 ◽  
Vol 16 (No. 1) ◽  
pp. 59-66
Author(s):  
Xiaoyan Yang ◽  
Chuandong Zhang ◽  
Haiping Gu ◽  
Xiangwei Chen ◽  
Erhui Guo

Organic acids could improve the phosphorus (P) availability through enhancing the release of inorganic phosphorus (P<sub>i</sub>) in the soil. However, the effects of organic acids on the P<sub>i</sub> release are still poorly understood, especially from soils with different organic matter contents. Here, a biochemically produced humic acid and P fertiliser were added to the soil to modify the content of the soil organic matter (SOM) and soil P, respectively. And then the soil samples were incubated at 25 °C for 30 days. The release of P<sub>i</sub> fractions (such as H<sub>2</sub>O-P<sub>i</sub>, NaHCO<sub>3</sub>-P<sub>i</sub>, NaOH-P<sub>i</sub>, HCl-P<sub>i</sub>, and Residual-P) from the soils with different organic matter contents in the presence of citric, oxalic, and malic acids was evaluated using a sequential chemical fractionation method. The results showed that the release of the NaHCO<sub>3</sub>-P<sub>i</sub>, NaOH-P<sub>i</sub>, and HCl-P<sub>i</sub> fractions also showed a decreasing trend with an increasing content of soil organic matter, and more NaOH-P<sub>i</sub> than the other P<sub>i</sub> fractions was generally released in the presence of organic acids. Considering the types of organic acids, oxalic acid and malic acid most effectively and least effectively released P<sub>i</sub>, respectively. The path analysis indicated that the NaOH-P<sub>i</sub> release had the highest direct and indirect effects on the total inorganic P (TP<sub>i</sub>) release. NaOH-P<sub>i</sub> was, therefore, the most effective source of P<sub>i</sub> in the Mollisols.


2014 ◽  
Vol 1081 ◽  
pp. 88-92
Author(s):  
Hui Liu ◽  
Jiu Lan Dai

Effect of organic matter and organic acid on the heavy metals, especially, chromium (Cr) release in the sediment was researched. Glucose and soluble organic starch was used as organic matter, as well, citric acid and ethylene diamine tetraacetic acid (EDTA) were simulated as organic acid. The results showed that best adsorption time of glucose on Cr was 5h, the optimal dosage was 0.1g g-1; best adsorption time of organic soluble starch was 4h, and the optimum adding amount of 0.08g/g; best adsorption time of citric acid was 5h, the best concentration 0.005mol g-1; optimal adsorption time of organic acid EDTA was 3h, the optimum adding amount of 0.12g g-1. Glucose, soluble starch and citric acid significantly effected on the release of Cr in the sediment, however, influence of EDTA on the release of Cr was not so evident.


1969 ◽  
Vol 49 (3) ◽  
pp. 365-373 ◽  
Author(s):  
M. Lévesque

Fulvic acid–metal–phosphate complexes prepared in the laboratory and corresponding complexes extracted (0.1 N NaOH and chelating resin) from a soil were characterized by means of electrophoresis, Sephadex gel filtration, and methods for differentiation of organic and inorganic phosphorus. The findings can be summarized as follows:(1) The prepared material in aqueous solution (after purification by dialysis) comprised three different entities: a fulvic acid–metal–phosphate complex, a fulvic acid–metal complex, and unbonded inorganic phosphate. These entities were reaction products obtained during the formation of fulvic acid–metal–phosphate complexes.(2) Upon hydrolysis in mild alkaline media, the metal–phosphate bonds of the fulvic acid–metal–phosphate complexes were broken; the fulvic acid–metal complexes, freed from the phosphate, remained intact.(3) While metal ions were necessary for bridging phosphorus and fulvic acid, phosphorus in turn may have bridged the fulvic acid–metal units.(4) Significant amounts of complexed inorganic phosphorus were found intermixed with organic phosphorus compounds in soil extracts; this suggested the existence of organic matter metal–phosphate complexes in soil.


1981 ◽  
Vol 38 (8) ◽  
pp. 978-981 ◽  
Author(s):  
Wayne S. Gardner ◽  
Thomas F. Nalepa ◽  
Michael A. Quigley ◽  
John M. Malczyk

Phosphate release rates by Stylodrilus heringianus, tubificids, and Chironomus spp. were quantified in laboratory experiments by incubating the animals in wet sand under two temperature regimes (5 and 20 °C) and under two nutritional states (full and empty guts). Inorganic phosphorus release rates (± SE) for animals incubated 24 h ranged from 0.12 ± 0.02 (n = 5) nmol phosphorus (P)∙(mg ash-free dry weight)−1∙h−1 for S. heringianus beginning with cleared guts at 5 °C to 0.81 ± 0.09 (n = 5) nmol P∙(mg ash-free dry weight)−1∙h−1 for chironomids beginning with full guts at 20 °C. Calculations based on total invertebrate bio-mass and mean basal release rate suggest that benthic invertebrate excretion could account for most P released from aerobic Lake Michigan sediments.Key words: phosphorus, benthic invertebrates, macroinvertebrates, excretion, nutrients, sediments, nutrient release


2016 ◽  
Vol 106 ◽  
pp. 37-46 ◽  
Author(s):  
Christopher W. Simmons ◽  
Brendan Higgins ◽  
Simon Staley ◽  
Lawrence D. Joh ◽  
Blake A. Simmons ◽  
...  

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243582
Author(s):  
Mengmeng Wang ◽  
Huifen Zhang ◽  
Menggaoshan Chen ◽  
Liuyan Yang ◽  
Yichen Yang

Bloom-forming cyanobacteria dramatically influence nutrient cycling in eutrophic freshwater lakes. The phosphorus (P) assimilation and release of bloom-forming cyanobacteria significantly may also affect the phosphorus source and amounts in water. To understand the phosphorus release process of bloom-forming cyanobacteria below the accumulated surface and sedimentary bloom-forming cyanobacteria, the degradation of bloom-forming cyanobacteria dominated by Microcystis spp. at different cell density in the dark was investigated over a 25-day microcosm experiment. The dissolved inorganic phosphorus (DIP) and dissolved total phosphorus (DTP) contents increased with the increment of cyanobacterial density, and the dark status markedly increased the proportion of DIP in water during the decline period of bloom-forming cyanobacteria. Meanwhile, the process of cyanobacterial apoptosis accompanied by the changes of malondialdehyde (MDA) and phosphatase (AKP) contents, and the increases of superoxide dismutase (SOD) and catalase (CAT) activities of cyanobacteria in the dark, especially in low-density groups (5.23×108 cells L-1), which further affect the physicochemical water parameters. Moreover, the DIP release from high-density cyanobacteria (7.86×107 cells L-1~5.23×108 cells L-1) resulted from the relative abundance of organophosphorus degrading bacteria in the dark. Therefore, the fast decay of cyanobacteria in the dark could accelerate DIP release, the high DIP release amount from accumulated bloom-cyanobacteria provide adequate P quickly for the sustained growth of cyanobacteria.


Author(s):  
Van Nu Thai Thien ◽  
Dang Viet Hung ◽  
Nguyen Thi Thanh Hoa

Anaerobic/Anoxic/Oxic – Membrane BioReactor (A2O-MBR) system was used to enhance simultaneous removal of nitrogen and phosphorus from brewery wastewater. The A2O unit containing microorganisms with short solids retention time (SRT) was employed mainly for removal of organic matter and phosphorus together with denitrification. The MBR containing microorganisms with long SRT was employed mainly for nitrification of NH4+-N and recirculation of NO3--N. The model of A2O-MBR system made from polyacrylic with the capacity of 49.5 liters was operated with hydraulic retention times decreased from 24, 18 to 12 hours corresponding to organic loading rates increased from 0.50, 0.75 to 1.00 kg COD/m3.day. The results showed that the model not only treated organic matter well but also nearly completely removed both nitrogen and phosphorus. For all three loading rates, chemical oxygen demand (COD) concentration decreased significantly in the anaerobic and anoxic compartments of the A2O unit, indicating that most of organic matter was utilized in the anaerobic and anoxic compartments for phosphorus release and denitrification, respectively. Nitrification in the MBR was almost perfectly completed, with average NH4 +-N removal efficiencies of over 98%. Denitrification in the anoxic compartment happened as much as possible. Demands for the development of PAOs, which were responsible for enhanced biological phosphorus removal (EBPR) processes, could be provided. For loading rate of 0.75 kg COD/m3.day, treatment efficiencies of COD, NH4+-N, total nitrogen (TN) and total phosphorus (TP) of the model were the highest as 95.4, 99.2, 86.7 and 84.6%, respectively. Output values of these parameters were within the limits of Vietnam National Technical Regulation on Industrial Wastewater (QCVN 40:2011/BTNMT), column A. The model of A2O-MBR system was capable of achieving effluents with very low nitrogen and phosphorus concentrations from brewery wastewater.  


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