scholarly journals The Study of Phosphate Release from Artificial Sediment into Water Body Using Diffusive Gradient in Thin Film (DGT) Device in Oxic Condition

2020 ◽  
Vol 20 (2) ◽  
pp. 395
Author(s):  
Ardina Purnama Tirta ◽  
Asep Saefumillah ◽  
Foliatini Foliatini ◽  
Herawati Herawati

The phenomenon of phosphate release in sediments into water bodies under oxic environment has been investigated using the Diffusive Gradient in Thin Film (DGT) technique. This research consists of several stages: polymer synthesis and DGT probe assembly, sediment sampling, DGT deployment in oxic conditions, and phosphate analysis from DGT adsorption results. Acrylamide polymer was successfully synthesized with a composition 15% acrylamide; N-N'-methylenebisacrylamide 0.1% and ferrihydrite as binding gels. DGT probes were assembly by placing a 16 x 3.2 cm polyacrylamide gel, binding gels and filter membranes on the DGT probes. The sediment sample was taken from the Bogor Botanical Gardens at the coordinates 6°36’00.6” S; 106°47’51.0” E. The DGT probe was placed in sediment samples for 1, 3 and 7 days in oxic conditions. After the prescribed time, the binding gel was removed and cut every 1 cm depth, then eluted using 0.25 M H2SO4 and the phosphate concentration was measured using spectrophotometry method. The results showed that the phosphate concentration tends to be higher with the increasing incubation time and depth. Maximum CDGT phosphate released on day 1, day 3 and day 7 were 1.00 µg/L at a depth of 14 cm, 6.61 µg/L at a depth of 14 cm, and 20.92 µg/L at a depth of 11 cm respectively. This ensures that the phosphate in water bodies comes from biogeochemical processes that occur in sediments and is successfully measured through DGT techniques.

2000 ◽  
Vol 42 (3-4) ◽  
pp. 265-272 ◽  
Author(s):  
T. Inoue ◽  
Y. Nakamura ◽  
Y. Adachi

A dynamic model, which predicts non-steady variations in the sediment oxygen demand (SOD) and phosphate release rate, has been designed. This theoretical model consists of three diffusion equations with biochemical reactions for dissolved oxygen (DO), phosphate and ferrous iron. According to this model, step changes in the DO concentration and flow velocity produce drastic changes in the SOD and phosphate release rate within 10 minutes. The vigorous response of the SOD and phosphate release rate is caused by the difference in the time scale of diffusion in the water boundary layer and that of the biochemical reactions in the sediment. Secondly, a negative phosphate transfer from water to sediment can even occur under aerobic conditions. This is caused by the decrease in phosphate concentration in the aerobic layer due to adsorption.


1988 ◽  
Vol 140 ◽  
pp. 24-26
Author(s):  
P.W.U Appel ◽  
C Knudsen

In 1982 scheelite was identified in stream sediments in the: Nuuk/Godthåb area, about 600 km south of Atâ. Subsequentlya regional stream-sediment programme was carried out in the Nuuk area from 1982 to 1987 as a result of which scheelite was found to be quite abundant in the 3800 m.y. old Isukasia supracrustalrocks as well as in the 3300 to 3000 m.y. old Malene supracrustal sequence (Appel, 1988). It was also recognised that there is a close correlation between the number of scheelite grains and the gold content of the heavy mineral concentrates in the Nuuk area (Appel, 1988). In the Ata area (fig. 1) extensive outcrops of supracrustal rocks are found. In these supracrustals, which have been metamorphosed to greenschist and amphibolite facies, abundant sulphide-rich horizons are found, as well as sulphide-bearing breccia zones with appreciable gold contents (Knudsen et al., 1988). During the 1987 field season geological reconnaissance mapping was carried out in two of the supracrustal areas and the gneiss-granite complex enclosing the supracrustal rocks ·was investigated (Knudsen et al., 1988). A limited programme of stream-sediment sampling was carried out in the Atâ area, where stream sediment samples were collected in all the main streams draining the supracrustal rocks.


Author(s):  
Yadong Kong ◽  
Ping Lu ◽  
Tao Yuan ◽  
Jinghui Niu ◽  
Zhaoji Li ◽  
...  

Swimming in surface water bodies (e.g., lakes, rivers) can expose the human body to substantial risk of infection by Cryptosporidium. These findings are from a one-year investigation on the occurrence and distribution of the protozoan parasite Cryptosporidium in Yunlong Lake, Xuzhou, China. Cryptosporidium oocysts were detected by immunofluorescence microscopy. From January to November of 2015, 180 samples (120 water samples and 60 sediment samples) were collected and analyzed. Among them, 42 (35%) water samples and 28 (47%) sediment samples tested positive for Cryptosporidium. The concentration of Cryptosporidium oocysts in the water samples was 0–8/10 L and 0–260/g in sediment samples. Results revealed that July was the highest risk period for both swimming and diving with an estimated probability of infection from swimming of greater than 18 per 10,000 swim sessions. It was concluded that swimming or diving in Yunlong Lake has a higher risk of Cryptosporidium infection than the acceptable risk level set by the United States Environmental Protection Agency. Thus, regular monitoring of water quality in recreation water bodies is strongly recommended.


2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Khairunisa N. Aulia ◽  
Hikmat Kasmara ◽  
Tatang S. Erawan ◽  
Suhartati M. Natsir

<p>Research of water condition of coral reefs with foraminifera benthic as bioindicator based on FORAM Index (FI) in Banggai Islands, Province of Central Sulawesi was conducted by P2O-LIPI, Jakarta team in July 2011.  This study was an exploratory research, conducted using survey methods. Sediment sampling was collected by a Van Veen Grab and measurement of other biotic and abiotic parameters was performed in 8 point sampling stations scattered in Banggai islands. Sediment samples were analyzed qualitatively and quantitatively to identify the types of foraminifera, determines FORAM Index, and find out  the relationship between FORAM Index with condition of coral reefs views by coral cover. The results showed that foraminifera benthonic as bioindicator were 75 species, which belong to  33 genera. Water conditions of Banggai Islands by FORAM Index (FI) values ​​ranged from 2.99 to 5.54. There was a fairly close relationship between FI with condition of coral reefs views by percentage coral cover in Banggai Islands.</p> <p>Keywords : coral reefs, FORAM Index, foraminifera benthic, Banggai Islands</p>


2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Khairunisa N. Aulia ◽  
Hikmat Kasmara ◽  
Tatang S. Erawan ◽  
Suhartati M. Natsir

Research of water condition of coral reefs with foraminifera benthic as bioindicator based on FORAM Index (FI) in Banggai Islands, Province of Central Sulawesi was conducted by P2O-LIPI, Jakarta team in July 2011.  This study was an exploratory research, conducted using survey methods. Sediment sampling was collected by a Van Veen Grab and measurement of other biotic and abiotic parameters was performed in 8 point sampling stations scattered in Banggai islands. Sediment samples were analyzed qualitatively and quantitatively to identify the types of foraminifera, determines FORAM Index, and find out  the relationship between FORAM Index with condition of coral reefs views by coral cover. The results showed that foraminifera benthonic as bioindicator were 75 species, which belong to  33 genera. Water conditions of Banggai Islands by FORAM Index (FI) values ​​ranged from 2.99 to 5.54. There was a fairly close relationship between FI with condition of coral reefs views by percentage coral cover in Banggai Islands. Keywords : coral reefs, FORAM Index, foraminifera benthic, Banggai Islands


2019 ◽  
Vol 19 (3) ◽  
pp. 615
Author(s):  
Askal Maimulyanti ◽  
Budiawan Budiawan ◽  
Asep Saefumillah ◽  
Heny Suseno

The diffusive gradient in thin film (DGT) is an analytical technique to determine phosphate in the environment. This technique uses a thin film diffusive hydrogel in contact with a binding phase (ferrihydrite) to binding of phosphate. The released phosphate from marine sediment of Jakarta Bay was studied by DGT technique for effect of salinity and oxygen condition. Effect of salinity was observed by NaCl concentration from 0-35 g/L. The maximum phosphate release from sediment was occurred at the concentration of NaCl 30 g/L with incubation for 15 days with phosphate released at 113.99 μg/L, MDGT of 4.7723 μg and CDGT of 17.56 μg/L. The experiment showed the increase of MgCl2 and CaCl2 concentration reduced phosphate release from sediment. The condition of oxygen indicating the release of phosphate under anaerobic conditions is greater than the aerobic condition. The aerobic conditions with incubation for 21 days showed the release of phosphate from sediment to overlying water of 124.72 μg/L, MDGT of 2.4492 μg and CDGT of 6.4380 μg/L. Anaerobic conditions with incubation for 21 days showed phosphate release from sediment to overlying water of 208.62 μg/L, MDGT of 6.1081 μg and CDGT of 16.06 μg/L. The experiment shows that salinity and oxygen concentration influences phosphate release from marine sediment of Jakarta Bay.


2016 ◽  
Author(s):  
F. Hu ◽  
K. Bolding ◽  
J. Bruggeman ◽  
E. Jeppesen ◽  
M. R. Flindt ◽  
...  

Abstract. This study presents FABM-PCLake, a complete redesign of the PCLake aquatic ecosystem model, which we implemented into the Framework for Aquatic Biogeochemical Models (FABM). In contrast to the original model, which was designed for temperate, fully mixed freshwater lakes, the new FABM-PCLake represents an integrated aquatic ecosystem model that enables simulations of hydrodynamics and biogeochemical processes for zero dimensional, one-dimensional as well as three-dimensional heterogeneous environments. FABM-PCLake describes interactions between multiple trophic levels, including piscivorous, zooplanktivorous and benthivorous fish, zooplankton, zoobenthos, three groups of phytoplankton and rooted macrophytes. The model also accounts for oxygen dynamics and nutrient cycling for nitrogen, phosphorus and silicon, both within the pelagic and benthic domains. FABM-PCLake includes a two-way communication between the biogeochemical processes and the physics, where some biogeochemical state variables (e.g., phytoplankton) influence light attenuation and thereby the spatial and temporal distributions of light and heat. At the same time, the physical environment, including water currents, light and temperature influence a wide range of biogeochemical processes. The model enables studies on ecosystem dynamics in physically heterogeneous environments (e.g., stratifying water bodies, and water bodies with horizontal gradient in physical and biogeochemical properties), and through FABM also enables data assimilation and multi-model ensemble simulations. Examples of relevant model applications include climate change impact studies and environmental impact assessment scenarios for lakes and reservoirs worldwide.


Author(s):  
Rocío Montes de Oca-Palma ◽  
Marcos Solache-Ríos ◽  
Melania Jiménez-Reyes ◽  
José Juan García-Sánchez ◽  
Perla Tatiana Almazán-Sánchez

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