Phosphorus loss and speciation in overland flow from a plantation horticulture catchment and in an adjoining waterway in coastal Queensland, Australia

Soil Research ◽  
2012 ◽  
Vol 50 (6) ◽  
pp. 515 ◽  
Author(s):  
Peter R. Stork ◽  
David J. Lyons
Keyword(s):  
Overland Flow ◽  
Weighted Average ◽  
Aquatic Organisms ◽  
Molar Ratio ◽  
Storm Events ◽  
N Losses ◽  
Marine Habitats ◽  
Storm Flow ◽  
High Concentrations ◽  
Total P

Phosphorus (P) in overland flow from horticulture farms in coastal Queensland, Australia, could eutrophy coastal freshwater and marine habitats environments nearby. The potential for such eutrophication was investigated in a coastal macadamia plantation under commercial production. During the 13-month study, P losses in overland flow were quantified in a 0.24-ha farm catchment with a 3.1% gradient, during five consecutive storm events. These events were within expected short- and long-term episodic rainfall frequencies and intensities. Runoff occurred when such storms generated between 20–40 mm/h of rainfall for >9 min. Calculated annual losses of total P were 0.32 kg/ha.year, comprising dissolved inorganic P (DIP, 0.28 kg/ha.year), particulate P (0.03 kg/ha.year), and dissolved organic P (0.01 kg/ha.year). DIP represented 88% of all losses and this was attributed to excessive fertilisation and untimely applications. Losses of total P were generally higher than those reported in comparable studies. Concentrations of DIP in runoff were 20–200-fold higher than those found in other coastal catchments in Queensland. High concentrations of DIP were present in the topsoil of the non-fertilised, inter-row areas of the farm catchment and this was attributed to transfer and deposition of DIP from adjacent fertilised tree beds during storm flow. Therefore, it can be expected that farm runoff will be enriched with DIP from these areas for an indeterminate period despite any future remediation to fertiliser management. The weighted average of DIP in farm runoff was 2.01 mg/L, whereas it was 0.005 mg/L in a catchment stream bordering the farm, showing a steep concentration gradient between the two ecosystem compartments. Together with nitrogen (N) losses in runoff, reported previously, an N : P molar ratio of 2 : 1 was contained in the farm runoff. This was well below the growth-limiting threshold for aquatic organisms, as determined by the Redfield ratio of 16 : 1 (N : P). The entry of nutrient-enriched farm runoff, as detailed in this study, into the catchment stream and the proximity of such waterways (8 km) to the coastline may also have implications for the near-shore (oligotrophic) marine environment during periods of storm flow. Altogether, this work revealed the high risk of eutrophication from farming landscapes such as the one under study.

Preliminary assessment of the ability of detainment bunds to attenuate sediment and phosphorus transported by surface runoff in the Lake Rotorua catchment

2020 ◽  
Vol 60 (1) ◽  
pp. 154 ◽  
Author(s):  
Brian Levine ◽  
Lucy Burkitt ◽  
Dave Horne ◽  
Leo Condron ◽  
Chris Tanner ◽  
...  
Keyword(s):  
Water Quality ◽  
Surface Runoff ◽  
Overland Flow ◽  
Nutrient Management ◽  
Suspended Sediments ◽  
Management Plan ◽  
Mitigation Strategy ◽  
Storm Events ◽  
Earthen Dam ◽  
Total P

Water-quality impairment due to excess nutrients entering Lake Rotorua has been recognised since the 1960s. So as to improve water-quality, the 2012 Lake Rotorua Nutrient Management Plan has set a target to reduce phosphorus (P) loads delivered to the lake by 10 t/year from a baseline of ~40 t P/year. Dissolved P and sediment-bound P loss from agriculture have been identified as significant sources of P entering the lake. Storm periods present significant opportunities to mitigate these losses. Detainment bunds (DBs) are a mitigation strategy that could potentially decrease P losses in storm events. A detainment bund is a low earthen dam constructed on productive pasture, which is capable of temporarily ponding large quantities of overland flow delivered by storm-generated ephemeral streams. Prior research on DBs and sedimentation basins serves as a proof of concept for the technology; however, there is no quantitative data available on the capacity of DBs to attenuate contaminants under New Zealand conditions. Quantification of DB performance is essential to the potential implementation of the technology at regional or national scales, and to the modelling of treatment efficacy in nutrient-management software such as OVERSEER®. The present study reports on preliminary data from a DB receiving surface runoff from 19.7 ha within the Lake Rotorua catchment during three contrasting storm events. The results indicated that retaining water in DBs resulted in discharges with decreased volumes of water and decreased concentrations of suspended sediments, dissolved reactive P and total P. Load attenuation related to event size and resulted in decreased loads of sediment (14–91%), dissolved reactive P (19–69%) and total P loads (18–67%) discharged downstream. These preliminary results indicated the potential of this mitigation strategy to decrease loads of sediment and P delivered to Lake Rotorua by surface runoff from pastoral agriculture.

Apoprotein C effect on triglyceride transport in tandem-perfused rat hind end and liver

1984 ◽  
Vol 247 (3) ◽  
pp. G305-G310
Author(s):  
W. J. Kortz ◽  
J. R. Nashold ◽  
M. R. Greenfield ◽  
H. Hilderman ◽  
S. H. Quarfordt
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Fatty Acyl ◽  
Liver Fat ◽  
Molar Ratio ◽  
Perfusion System ◽  
In Vitro Perfusion ◽  
Arterial Inflow ◽  
High Concentrations

The metabolism of double-labeled triglyceride in a synthetic emulsion was defined in an in vitro perfusion system of rat hind end and liver described previously [Am. J. Physiol. 245 (Gastrointest. Liver Physiol. 8): G106-G112, 1983]. The metabolism of [3H]glycerol-[14C]triolein was defined in the absence of added apoproteins and with additions of human CII and both CII and CIII. Without apoprotein, a pronounced lipolysis of the triglyceride was recognized by high concentrations of radiolabeled glycerol and free fatty acid in the perfusate. The removal of an aliquot of hind-end venous effluent 5 min after adding the labeled triglyceride emulsion to the arterial inflow demonstrated a brisk lipolysis of the substrate when incubated outside the perfusion system. The addition of CII protein to the emulsion before its introduction into the tandem system eliminated perfusate lipolysis, both within the perfusion system and in incubations of aliquots withdrawn from the system. Intravascular lipolysis was not seen with triglyceride emulsions containing both CII and CIH or when an aliquot of hind-end venous effluent was incubated with triglycerides that had not been exposed to the perfusion system. The intravascular lipolysis observed for the [14C]triglyceride added to the tandem system without apoproteins was associated with relatively greater recoveries of 14C-fatty acyl in liver, fat, and muscle and relatively greater recoveries of 14CO2 than when CII alone or both CII and CIII were added with the triglyceride. The addition of CIII to CII in a 1:1 molar ratio increased the recovery of 14C-fatty acyl in muscle and the recovery as 14CO2.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The Relevance of Grated Inlets within Surface Drainage Systems in the Field of Urban Flood Resilience. A Review of Several Experimental and Numerical Simulation Approaches

2021 ◽  
Vol 13 (13) ◽  
pp. 7189
Author(s):  
Beniamino Russo ◽  
Manuel Gómez Valentín ◽  
Jackson Tellez-Álvarez
Keyword(s):  
Overland Flow ◽  
Drainage System ◽  
Critical Conditions ◽  
Hydraulic Efficiency ◽  
Storm Events ◽  
Urban Resilience ◽  
Urban Flood ◽  
Drainage Systems ◽  
Surface Drainage ◽  
Intense Storm

Urban drainage networks should be designed and operated preferably under open channel flow conditions without flux return, backwater, or overflows. In the case of extreme storm events, urban pluvial flooding is generated by the excess of surface runoff that could not be conveyed by pressurized sewer pipes, due to its limited capacity or, many times, due to the poor efficiency of surface drainage systems to collect uncontrolled overland flow. Generally, the hydraulic design of sewer systems is addressed more for underground networks, neglecting the surface drainage system, although inadequate inlet spacings and locations can cause dangerous flooding with relevant socio-economic impacts and the interruption of critical services and urban activities. Several experimental and numerical studies carried out at the Technical University of Catalonia (UPC) and other research institutions demonstrated that the hydraulic efficiency of inlets can be very low under critical conditions (e.g., high circulating overland flow on steep areas). In these cases, the hydraulic efficiency of conventional grated inlets and continuous transverse elements can be around 10–20%. Their hydraulic capacity, expressed in terms of discharge coefficients, shows the same criticism with values quite far from those that are usually used in several project practice phases. The grate clogging phenomenon and more intense storm events produced by climate change could further reduce the inlets’ performance. In this context, in order to improve the flood urban resilience of our cities, the relevance of the hydraulic behavior of surface drainage systems is clear.

Structural characteristics of tetanolysin and its binding to lipid vesicles

1982 ◽  
Vol 152 (2) ◽  
pp. 888-892
Author(s):  
S Rottem ◽  
R M Cole ◽  
W H Habig ◽  
M F Barile ◽  
M C Hardegree
Keyword(s):  
Structural Characteristics ◽  
Lipid Vesicles ◽  
Molar Ratio ◽  
Molar Ratios ◽  
High Concentrations

Tetanolysin binding to lipid vesicles was found to depend on the molar ratio of cholesterol to phospholipid, being low in vesicles containing up to 20 mol% cholesterol and high in vesicles containing more than 33 mol%. High concentrations of purified tetanolysin preparations formed arc- and ring-shaped structures. The structures were not readily detectable in diluted preparations unless incubated with lipid vesicles containing high molar ratios of cholesterol to phospholipid. It is suggested that the toxin is concentrated on the vesicles to local concentrations high enough to form the arcs and rings.

scholarly journals Development of Daphnia magna under exposure to the xenobiotic octylphenol

2014 ◽  
Vol 6 (2) ◽  
pp. 155-158
Author(s):  
Thanh Son Dao ◽  
Thi My Chi Vo ◽  
Hong Lan Chi Do ◽  
Phuoc Dan Nguyen
Keyword(s):  
Developing Country ◽  
Daphnia Magna ◽  
Aquatic Organisms ◽  
Environmental Concerns ◽  
Human Beings ◽  
Ecological Health ◽  
Potential Toxicity ◽  
Chronic Effects ◽  
High Concentrations ◽  
Significant Mortality

Xenobiotics are of human and environmental concerns due to their potential toxicity. Octylphenol is one of the very common and daily used xenobiotics in door and out door activities of human beings. Toxicity of octylphenol to aquatic organisms, especially to zooplankton (e.g. Daphnia magna) was investigated but not fully understood. In this study we evaluated the chronic effects of octylphenol at the concentrations of 5, 50 and 500 µg L-1 on Daphnia magna over a period of 14 days. The results showed that low concentration of octylphenol (5 µg L-1) stimulated the maturation while high concentrations of the chemical (50 and 500 µg L-1) caused a significant mortality to the Daphnia. Besides, all the tested concentrations of octylphenol had serious impacts on fecundity and growth of the animals. Investigations on the presence, distribution, fate and toxicity of xonobiotics including octylphenol in the developing country environment are suggested for human, environmental and ecological health protection. Những hợp chất tổng hợp đang là mối quan ngại cho con người và môi trường vì khả năng gây độc của chúng. Octylphenol là một trong những hợp chất tổng hợp được sử dụng phổ biến và thường xuyên trong những hoạt động của con người trong nhà và ngoài trời. Độc tính của octylphenol đối với thủy sinh vật, đặc biệt đối với động vật phù du (vd. Daphnia magna) mặc dù đã được nghiên cứu nhưng vẫn chưa được hiểu biết đầy đủ. Trong nghiên cứu này, chúng tôi đánh giá ảnh hưởng mãn tính của octylphenol ở các nồng độ 5, 50 và 500 µg/lít lên Daphnia magna trong thời gian 14 ngày. Kết quả cho thấy ở nồng độ octylphenol thấp (5 µg/lít) kích thích sự thành thục của sinh vật trong khi ở nồng độ cao hơn (50 và 500 µg/lít) gây chết đáng kể Daphnia. Bên cạnh đó, tất cả các nồng độ ocytlphenol dùng trong thí nghiệm gây ảnh hưởng nghiêm trọng lên sức sinh sản và sinh trưởng của sinh vật. Nghiên cứu về sự hiện diện, phân bố, phát tán và độc tính của những chất tổng hợp bao gồm octylphenol ở các nước đang phát triển nên được tiến hành vì mục tiêu bảo vệ sức khỏe con người, môi trường và hệ sinh thái.

scholarly journals Concentrations and Loads of Dissolved and Particulate Organic Carbon in Urban Stormwater Runoff

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1031 ◽  
Author(s):  
Stefan Kalev ◽  
Gurpal S. Toor
Keyword(s):  
Organic Carbon ◽  
Stormwater Runoff ◽  
Light Availability ◽  
Rain Gauge ◽  
Urban Landscapes ◽  
Storm Events ◽  
Wet Season ◽  
The Difference ◽  
Urban Stormwater Runoff ◽  
High Concentrations

Urban landscapes are significant contributors of organic carbon (OC) in receiving waters, where elevated levels of OC limit the light availability, increase the transport of pollutants, and result in high costs of potable water treatment. Our objective in this study was to investigate the concentrations, fractions (dissolved and particulate), and loads of OC in a residential catchment (3.89 ha drainage area) located in Florida, United States. The outlet of the stormwater pipe draining the residential catchment was instrumented with an automated sampler, a flowmeter, and a rain gauge. The rainfall and runoff samples collected over 25 storm events during the 2016 wet season (June to September) were analyzed for dissolved organic carbon (DOC) and total organic carbon (TOC), with particulate OC (POC) calculated as the difference between TOC and DOC. Mean concentration of DOC was 2.3 ± 1.7 mg L−1 and POC was 0.3 ± 0.3 mg L−1 in the rainfall, whereas DOC was 10.5 ± 6.20 mg L−1 and POC was 2.00 ± 4.05 mg L−1 in the stormwater runoff. Concentrations of DOC were higher during the rising limb of the hydrograph in 15 out of 25 storm events, suggesting flushing of DOC, with an increase in the amount of runoff, from the landscape sources in the residential catchment. The estimated total export of OC during the 2016 wet season was 66.0 kg ha−1, of which DOC was 56.9 kg ha−1 (86.2% of TOC), and POC was 9.1 kg ha−1 (13.8% of TOC). High concentrations and loads of OC, especially DOC, in the stormwater runoff imply that residential catchments in urban watersheds are hot-spots of DOC influx to water bodies. Reducing DOC transport in the urban landscapes is complex and require identifying the origin of DOC and then using site-specific targeted approaches to mitigate DOC loss.

scholarly journals Characteristics of Sedimentary Organic Matter and Phosphorus in Minor Rivers Discharging into Zhejiang Coast, China

Geosciences ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 357
Author(s):  
Pei Sun Loh ◽  
Long-Xiu Cheng ◽  
Shi-Yuan Lin ◽  
Selvaraj Kandasamy
Keyword(s):  
Organic Matter ◽  
Surface Sediments ◽  
Syringic Acid ◽  
Molar Ratio ◽  
Southeast China ◽  
Qiantang River ◽  
Decomposition Of Organic Matter ◽  
Continuous Decomposition ◽  
Total P ◽  
Total Lignin

In this study, the spatial distribution of lignin-derived phenols, bulk elemental composition and different phosphorus (P) species in surface sediments along six rivers discharging into Zhejiang coast, Southeast China, were investigated to improve the understanding of the carbon and P dynamics in these small river systems. The Shuang, Jiao, Ximen, Feiyun and Ao Rivers have total organic carbon (TOC) ranging from 0.29% to 2.77% and Λ (total lignin in mg/100 mg TOC) ranging from 0.24 to 4.24; Qiantang River has the lowest Λ (0.08–0.19) but the highest TOC (1.05%–6.46%). Jiao, Ximen, Feiyun and Ao Rivers have mean the total P (TP) and bioavailable P (BAP) of 34 to 124 mg/kg and 29 to 89 mg P/kg, and mean OC/OP molar ratio of 397–917. Qiantang River has the lowest mean TP and BAP of 13 mg P/kg and 7 mg P/kg, and highest OC/OP of 18,753; whereas Shuang River has the highest mean TP and BAP of 645 mg P/kg and 559 mg P/kg, and lowest mean OC/OP of 90. The lowest Λ, TP and BAP, but highest OC/OP, in the Qiantang River could be due to tidal bore causing rapid cycling of carbon and P. Trends of slight decrease in abundance of OC, Λ, TP and BAP, but increasing ratios of vanillic acid to vanillin [(Ad/Al)v], syringic acid to syringaldehyde [(Ad/Al)s] and OC/OP farther downstream of the rivers indicate a continuous decomposition of organic matter during transport along the rivers.

scholarly journals A multi-functional and multi-compartment constructed wetland to support urban waterway restoration

2018 ◽  
Vol 13 (4) ◽  
pp. 764-770 ◽  
Author(s):  
T. M. Adyel ◽  
M. R. Hipsey ◽  
C. Oldham
Keyword(s):  
Constructed Wetland ◽  
Flow System ◽  
Surface Flow ◽  
Base Flow ◽  
Low Flow ◽  
Nutrient Loads ◽  
Storm Events ◽  
Flow Conditions ◽  
Storm Flow ◽  
Diverse Area

Abstract This study assessed the significance of a multi-functional and multi-compartment constructed wetland (CW) implemented to restore a degraded urban waterway in Western Australia. The wetland was initially constructed as a surface flow system, then modified through the incorporation of the additional laterite-based subsurface flow system, with the potential for operation of a recirculation scheme and groundwater top-up during low water flows in summer. The CW performance was assessed by comparing nitrogen (N) and phosphorus (P) attenuation during base flow, high flow and episodic storm flow conditions. The performance varied from approximately 41% total nitrogen (TN) and 66% total phosphorus (TP) loads reduction during storm events, increasing up to 62% TN and 99% TP during low flow and summer recirculation periods. In overall, the CW attenuated about 45% TN and 65% TP loads from being delivered to the downstream sensitive river between 2009 and 2015. The CW design proved to be not only highly effective at reducing nutrient loads, but also improved the ecological services of the urban waterway by providing a diverse area for habitat and recreational activities.

scholarly journals Effect of Cadmium and Nickel Exposure on Early Development in Zebrafish (Danio rerio) Embryos

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3005
Author(s):  
Seyed Javid Aldavood ◽  
Louise C. Abbott ◽  
Zachary R. Evans ◽  
Daniel J. Griffin ◽  
MaKenzie D. Lee ◽  
...  
Keyword(s):  
Danio Rerio ◽  
Aquatic Organisms ◽  
Total Body Length ◽  
Hatching Rate ◽  
Spontaneous Movement ◽  
Low Concentrations ◽  
Combined Exposures ◽  
Low Exposure ◽  
High Concentrations ◽  
Danio Rerio Embryos

Exposure to even low concentrations of heavy metals can be toxic to aquatic organisms, especially during embryonic development. Thus, this study aimed to investigate the toxicity of nickel and cadmium in zebrafish (Danio rerio) embryos exposed to environmentally relevant concentrations of each metal alone or in combination from 4 h through to 72 h postfertilization. Neither metal altered survival, but individual and combined exposures decreased hatching rate. Whereas cadmium did not affect total body length, trunk area, eye diameter, or eye area, nickel alone and in combination with cadmium decreased each morphological parameter. Yolk sac area, an index of metabolic rate, was not affected by nickel, but was larger in embryos exposed to high cadmium concentrations or nickel and cadmium combined at high concentrations. Nickel decreased spontaneous movement, whereas cadmium alone or nickel and cadmium combined had no effect. Neither metal altered elicited movement, but nickel and cadmium combined decreased elicited movement. Myosin protein expression in skeletal muscle was not altered by cadmium exposure. However, exposure to nickel at low concentrations and combined exposure to nickel and cadmium decreased myosin expression. Overall, nickel was more toxic than cadmium. In conclusion, we observed that combined exposures had a greater effect on movement than gross morphology, and no significant additive or synergistic interactions were present. These results imply that nickel and cadmium are toxic to developing embryos, even at very low exposure concentrations, and that these metals act via different mechanisms.

scholarly journals 31P-NMR Metabolomics Revealed Species-Specific Use of Phosphorous in Trees of a French Guiana Rainforest

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3960
Author(s):  
Albert Gargallo-Garriga ◽  
Jordi Sardans ◽  
Joan Llusià ◽  
Guille Peguero ◽  
Dolores Asensio ◽  
...  
Keyword(s):  
Tree Species ◽  
French Guiana ◽  
31P Nmr ◽  
Principal Component ◽  
Distinct Species ◽  
Community Diversity ◽  
N:P Ratios ◽  
High Concentrations ◽  
Species Specific ◽  
Total P

Productivity of tropical lowland moist forests is often limited by availability and functional allocation of phosphorus (P) that drives competition among tree species and becomes a key factor in determining forestall community diversity. We used non-target 31P-NMR metabolic profiling to study the foliar P-metabolism of trees of a French Guiana rainforest. The objective was to test the hypotheses that P-use is species-specific, and that species diversity relates to species P-use and concentrations of P-containing compounds, including inorganic phosphates, orthophosphate monoesters and diesters, phosphonates and organic polyphosphates. We found that tree species explained the 59% of variance in 31P-NMR metabolite profiling of leaves. A principal component analysis showed that tree species were separated along PC 1 and PC 2 of detected P-containing compounds, which represented a continuum going from high concentrations of metabolites related to non-active P and P-storage, low total P concentrations and high N:P ratios, to high concentrations of P-containing metabolites related to energy and anabolic metabolism, high total P concentrations and low N:P ratios. These results highlight the species-specific use of P and the existence of species-specific P-use niches that are driven by the distinct species-specific position in a continuum in the P-allocation from P-storage compounds to P-containing molecules related to energy and anabolic metabolism.

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