Water chemistry gradient in a degraded bog area

2006 ◽  
Vol 53 (2) ◽  
pp. 63-71 ◽  
Author(s):  
R. Iqbal ◽  
S. Akimoto ◽  
K. Tokutake ◽  
T. Inoue ◽  
H. Tachibana

Surface and ground water was sampled in a degraded bog area 36 times during 1993–2003 at Five representative points: point E (natural area with Sphagnum as the main vegetal cover), point W (boundary between the natural and degraded areas), point W' (area installed with vinyl sheeting), point WW (area where Sasa thrives), and point NC (area with naturally formed ditches). Analysis of variance (ANOVA) was conducted for parameters measured in surface water and ground water at 0.5, 1.0, 1.5, and 2.0 m depths. “Sampling point” (i.e. locations along the degradation gradient) accounted for most of the variation in surface and ground water chemistry. It accounted for 30–80% of the total variation in pH, electrical conductivity, ammonia, dissolved nitrogen, major cations (Na+, K+, Ca2+ , Mg2+ ), alkalinity and dissolved organic carbon. “Year” accounted for more variation in nitrate, nitrite, chloride, and sulfate than the sampling point did, but the variation in dissolved reactive phosphorus and dissolved phosphorus concentrations was not based on any of the calculated variables.

Author(s):  
Junqiu Wu ◽  
Yue Zhao ◽  
Ran Zhao ◽  
Liming Jia ◽  
Zimin Wei

To explore the eutrophication degree in the typical lakes and reservoirs of the northeast region of China, the bioavailability of dissolved organic phosphorus (DOP) of the lakes has been examined in this study. The laboratory incubation was carried out at 20 °C for 55 days and the concentrations of total dissolved phosphorus (TDP), dissolved reactive phosphorus (DRP), DOP and the microbial biomass have been detected. Results showed that, during the process of incubation, the concentrations of TDP and DRP were increased, whereas the DOP was decreased, which leads to the decreased mineralization rate. In addition, the changes of microbial biomass were fluctuant, but they had significantly positive effects on the concentration changes and mineralization rate of DOP (p < 0.05). The correlation analysis among the phosphate fractions showed that the TDP significantly promoted the DRP concentration, mineralization rate of DOP and the cumulative mineralization of DOP. The kinetics model was conducted to predict the further mineralization of DOP and to analyze the pollution degree of the eight lakes and reservoirs. Accordingly, the lakes with high DRP and TDP had worse water quality and are prone to algae blooms.


1998 ◽  
Vol 55 (10) ◽  
pp. 2292-2299 ◽  
Author(s):  
Sandra E Cooke ◽  
Ellie E Prepas

We evaluated phosphorus (P) and inorganic nitrogen (IN) export from two agricultural and two forested watersheds on the nutrient-rich but relief-poor Boreal Plain. One agricultural stream was in a watershed that contained cropland, while the second consisted of mixed agricultural activities. Over the 2-year study, total dissolved phosphorus (TDP) concentrations were proportionately high, particularly in the agricultural streams. Flow-weighted TDP averaged 82% of the total phosphorus (TP) in the agricultural streams and 43% in the forested streams. In all watersheds, TDP was almost exclusively dissolved reactive phosphorus and most of the annual P export was in summer. The type of agricultural activity in the watershed influenced IN speciation; in the mixed agricultural watershed, 94% of IN export was ammonium, whereas 98% of IN load was nitrate from the cropland watershed. Disproportionately high TDP to TP export from agricultural watersheds suggests that, in areas of low relief and relatively high soil water P content, land clearing may influence dissolved more than particulate phosphorus export.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Qing Xu ◽  
Xiaoping Yu ◽  
Yafei Guo ◽  
Tianlong Deng ◽  
Yu-Wei Chen ◽  
...  

Overlying sediment and pore waters were collected in summer and winter at upstream (Jintang) and downstream (Neijiang) sites of the Tuohe River, which is one of the five largest tributaries of the Yangtze River in China. Phosphorus species, including soluble reactive phosphorus (SRP), soluble unreactive phosphorus (SUP), and total dissolved phosphorus (TDP), and some diagenetic constituents including dissolved Fe(II), Mn(II), and sulfide in overlying and pore waters, were measured systematically. The seasonal variations and vertical distributions of phosphorus species in overlying and pore waters at both sampling sites were obtained to elucidate some aspects of the transport and transformations of phosphorus. Based on the profiles of pore and overlying waters as well as the TDN/TDP data during an algal bloom in 2007, it was clearly demonstrated that phosphorus was the main factor limiting the phytoplankton growth in the Tuohe River.


Ground Water ◽  
1984 ◽  
Vol 22 (4) ◽  
pp. 412-417 ◽  
Author(s):  
Fawzia AI-Ruwaih
Keyword(s):  

2014 ◽  
Vol 05 (08) ◽  
pp. 694-702
Author(s):  
Jian Wang ◽  
Jingtian Zhang ◽  
Qiong Xie ◽  
Fengyu Zan ◽  
Shengpeng Zuo ◽  
...  

2017 ◽  
Vol 35 (3) ◽  
pp. 117-127
Author(s):  
Daniel E. Wells ◽  
Jeffrey S. Beasley ◽  
Edward W. Bush ◽  
Lewis. A. Gaston

Abstract Poultry litter ash (PLA) is a byproduct of bioenergy production and an effective P source for horticultural crops since it reduces P losses from container production due to its low P solubility. Experiments were conducted to determine effects of rate and placement of PLA on P loss from greenhouse crop production and growth and quality of two commonly-grown greenhouse crops, Verbena canadensis Britton ‘Homestead Purple' and Lantana camara L. ‘New Gold', by comparing two rates (140 and 280 g·m−3 P or 0.4 and 0.8 lb·yd−3) and two application methods (post-plant topdressed and pre-plant incorporated). Leachate-dissolved reactive phosphorus (DRP) concentrations were reduced by an average of 24% as P rate was reduced from 280 to 140 g·m−3, but were 134% less on average when PLA was topdressed instead of incorporated. Foliar P concentrations were less 33% and 44% for verbena and lantana, respectively when plants were topdressed compared to incorporated. Shoot biomass of verbena and lantana was 9% and 24% greater, respectively, when incorporating instead of topdressing PLA. As a P source, PLA should be pre-plant incorporated within the substrate at a total P rate between 140 g·m−3 (0.4 lb·yd−3) and 280 g·m−3 (0.8 lb·yd−3). Index words: phosphorus, poultry litter ash, Verbena canadensis Britton ‘Homestead Purple', Lantana camara L. ‘New Gold', dissolved reactive phosphorus. Species used in this study: ‘Homestead Purple' verbena (Verbena canadensis Britton); ‘New Gold' lantana (Lantana camara L.).


2021 ◽  
Author(s):  
Bernard CLEMENT ◽  
Vincent FELIX ◽  
Valentin BERTRAND

Abstract For the prediction of metals mixture ecotoxicity, the BLM approach is promising since it evaluates the amount of metals accumulated on the biotic ligand on the basis of water chemistry, i.e. species (major cations) competing with metals, and related toxicity. Based on previous work by Farley et al. 2015 (MMME research project), this study aimed at modelling toxicity of Cd:Cu mixtures (0:1–1:1–1:0–1:2 − 1:3 − 2:1–3:1–4:1–5:1–6:1) to the crustacean Daphnia magna (48h immobilization tests) and the microalga Pseudokirchneriella subcapitata (72h growth inhibition tests). The USGS model was chosen, assuming additivity of effects and accumulation of metals on a single site. The assumption that EDTA could contribute to toxicity through metals complexing was also tested, and potential effects due to reduction of ions Ca2+ absorption by metals were considered. Modelling started with parameter values of Farley et al. 2015 and some of these parameters were adjusted to fit modelled data on observed data. The results show that toxicity can be correctly predicted for the microalgae and that the hypothesis of additivity is verified. For daphnids, the prediction was roughly correct, but taking into account CuEDTA led to more realistic parameter values close to that reported by Farley et al. 2015. However, It seems that, for daphnids responses, metals interact either antagonistically or synergistically depending on the Cu:Cd ratio. Furthermore, synergy could not be explained by additional effects linked to a reduction of Ca absorption since this reduction, mainly due to Cd, increased inversely to synergy. Finally, the USGS model applied to our data was able to predict Cu:Cd mixture toxicity to microalgae and daphnids, giving rise to estimated EC50s roughly reflecting EC50s calculated from observed toxicity.


Geology ◽  
1996 ◽  
Vol 24 (11) ◽  
pp. 1049 ◽  
Author(s):  
Jay L. Banner ◽  
MaryLynn Musgrove ◽  
Yemane Asmerom ◽  
R. Lawrence Edwards ◽  
John A. Hoff

Author(s):  
Satoshi Hanawa ◽  
Tomonori Sato ◽  
Yuichiro Mori ◽  
Jin Oogiyanagi ◽  
Yoshiyuki Kaji ◽  
...  

In order to evaluate the water chemistry in the irradiation field during IASCC irradiation test, a water radiolysis code for IASCC irradiation loop system was developed. In the water radiolysis code, a multiple node model was introduced since the irradiation loop system has a wide rage temperature distribution as well as the dose distribution. To investigate the applicability of developed water radiolysis code, water chemistry at the water sampling point of the irradiation loop system was measured and compared with analytical results under several water chemistry conditions. Further, water chemistry distribution in the in-pile region as well as in the out-pile region was calculated by the developed water radiolysis code.


2015 ◽  
Vol 12 (2) ◽  
pp. 623-635 ◽  
Author(s):  
S. Blain ◽  
J. Capparos ◽  
A. Guéneuguès ◽  
I. Obernosterer ◽  
L. Oriol

Abstract. During KEOPS2 (Kerguelen Ocean and Plateau Compared Study 2), we determined dissolved inorganic and organic nitrogen and phosphorus species in the naturally fertilized region of Kerguelen Island (Southern Ocean). Above 150 m, stations were clearly separated by the polar front (PF), with concentrations of NO3-, NO2- and PO43- overall lower north of the PF than south. Though less pronounced, a similar trend was detectable for dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP). At all stations offshore and above the plateau, a subsurface maximum of NH4+ was observed between 50 and 150 m. We examined nutrient stoichiometry by calculating the linear combination N* = [NO3-]-16 [PO43-]. The majority of stations and depths revealed N* close to −3 μM; however, for surface waters north of the PF, N* increased up to 6 μM. This suggests a preferential uptake of PO43- versus NO3- by fast-growing diatoms. Using the tracer TNxs = [TDN]-16[TDP] (TDN, total dissolved nitrogen; TDP, total dissolved phosphorus) revealed that the dissolved organic fraction significantly contributed to changes in TNxs. TNxs values were negative for most stations and depths, and relatively constant in the 0–500 m layer. As for N*, the stations north of the PF had higher TNxs in the 0–100 m layer. We discuss this stoichiometric anomaly with respect to possible external sources and sinks of N and P. Additional data collected in February 2013 at two sites revealed the occurrence of a subsurface minimum of N* located just below the pycnocline, which denotes a layer where remineralization of particulate organic matter with low N : P ratio P, possibly associated with preferential remineralization of P versus N, persists throughout the season.


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