scholarly journals The phosphorus load and the variation of the trophic states of Cirata Reservoir (West Java, Indonesia) from 1988 to 2017

2020 ◽  
Vol 21 (9) ◽  
Author(s):  
Niken Pratiwi ◽  
ZULHAMSYAH IMRAN ◽  
INNA PUSPA AYU ◽  
ALIATI ISWANTARI ◽  
DWI YUNI WULANDARI

Abstract. Pratiwi NTM, Imran Z, Ayu IP, Iswantari A, Wulandari DY. 2020. The phosphorus load and the variation of the trophic states of Cirata Reservoir (West Java, Indonesia) from 1988 to 2017. Biodiversitas 21: 4176-4183. Cirata Reservoir was constructed in 1987 between Saguling and Jatiluhur Reservoirs; these are the three man-made cascading lakes in West Java, Indonesia. Cirata Reservoir has been used for floating cage aquaculture activities. The high organic content from the remains of the fish pellets raised the phosphorus (P) load, resulting in the eutrophication of the reservoirs. This research was aimed to assess the P load and the variation of the trophic states of the reservoir from year 1988 to 2017. The trophic states and the nutrients’ conditions of the water were determined using Myxophycean Index. Four groups of phytoplankton were found in the reservoir during observation: Cyanophyceae, Chlorophyceae, Bacillariophyceae, and Dinophyceae. In addition, one group was found in a smaller number of observations: Eugolenophyceae. Although the community structure of the phytoplankton has changed, the Cyanophyceae was always dominant in response against the condition of nutrients, especially P. The P load is closely related to the number of floating cages in the reservoir. This evidence showed that Cirata Reservoir tended to be relatively eutrophic. In general, despite that the P load tended to fluctuate, the trophic states of Cirata Reservoir remained dynamic in relatively high conditions; showed by the oligo-mesotrophic state during its first year of operation, then increased to eutrophic and hypertrophic by the next decade. Although the P load tended to decrease, it remains in the eutrophic condition in the recent time.

Author(s):  
Asela Del Carmen Rodríguez-Varela ◽  
Omar Alfredo Barreto-Segura ◽  
Horacio Vázquez-López

<p>The increasing anthropogenic development of the Veracruz Metropolitan Area demands the updating and monitoring of the region’s biodiversity, particularly on the spatial-temporal dynamics of those potential indicator groups of any disturbance. We present the first study on the Tanaidaceans of the Lagunar System of Mandinga, Veracruz, Mexico. Seven collections were made on submerged vegetation and sediments in dry season from 2008 to 2015 and one in the rainy season of the first year. Organisms were collected with a dredger and a Renfro-like net on submerged vegetation. One species from the suborder Apsudomorpha, <em>Discapseudes (Discapseudes) mexicanus</em> Gutu, 2006 and two from the suborder Tanaidomorpha, <em>Chondrochelia dubia</em> (Krøyer, 1842) and <em>Hargeria rapax</em> (Harger, 1879). The former recorded the highest distribution and abundance during the study period, confirming that <em>D. mexicanus </em>is a tanaidacean characteristic of the coastal systems of the Gulf of Mexico and it is associated with environments with high organic content in the sediments, while the other species were collected with lower abundances. In general, the downward trend in its abundance is noticeable over time, a fact that can be attributed to the constant modifications and alterations that SLM has undergone throughout the study period.</p>


2009 ◽  
Vol 03 (02) ◽  
pp. 77-88 ◽  
Author(s):  
HASANUDDIN Z. ABIDIN ◽  
HERI ANDREAS ◽  
TERUYUKI KATO ◽  
TAKEO ITO ◽  
IRWAN MEILANO ◽  
...  

Along the Java trench the Australian–Oceanic plate is moving and pushing onto and subducting beneath the Java continental crust at a relative motion of about 70 mm/yr in NNE direction. This subduction-zone process imposed tectonic stresses on the fore-arc region offshore and on the land of Java, thus causing the formation of earthquake fault zones to accommodate the plate movement. Historically, several large earthquakes happened in Java, including West Java. This research use GPS surveys method to study the inter-seismic deformation of three active faults in West Java region (i.e. Cimandiri, Lembang and Baribis faults), and the co-seismic and post-seismic deformation related to the May 2006 Yogyakarta and the July 2006 South Java earthquakes. Based on GPS surveys results it was found that the area around Cimandiri, Lembang and Baribis fault zones have the horizontal displacements of about 1 to 2 cm/yr or less. Further research is however still needed to extract the real inter-seismic deformation of the faults from those GPS-derived displacements. GPS surveys have also estimated that the May 2006 Yogyakarta earthquake was caused by the sinistral movement of the (Opak) fault with horizontal co-seismic deformation that generally was less than 10 cm. The post-seismic horizontal deformation of the July 2006 South Java tsunami earthquake has also been estimated using GPS surveys data. In the first year after the earthquake (2006 to 2007), the post-seismic deformation is generally less than 5 cm; and it becomes generally less than 3 cm in the second year (2007 to 2008).


1998 ◽  
Vol 44 ◽  
pp. 173-179
Author(s):  
C. Israelson ◽  
S. Bjorck ◽  
N. Noe Nygaard ◽  
C. J. Hawkesworth

We report the results of a U-series isotope study on Eemian lake sediments from Hollerup, western Denmark. The purpose is to examine the possibility of dating these, and similar, sediments with the 238U-23"h method. Two sedimentary facies were studied; carbonate-present, and virtually carbonate-free but organic-rich sediments. All carbonate-present sediments (5-95%) have (230ThP38U) values higher than unity and relatively radiogenic (23"W232Th) values between 2 and 6.5, indicating postdeposition removal of U, probably by percolation of ground water. Carbonate-free sediments, but with high organic content (40-60%) had (230Th/238U) values lower than 1 and 'model ages' between 89 and 199 ky. The large spread in ages and variation in U content for these sediment samples that were deposited over a much shorter time interval, indicate a complex postdepositional migration pattern of U, probably involving several episodes of leaching and absorption of U from ground water. Our results suggest that lake sediments, such as those found in Hollerup, are vulnerable to mobilization of U and its decay products and care should be taken when interpreting U-series disequilibrium data from such sediments. Future studies will concentrate on sediments that have been more deeply buried andor are less compacted and sealed from percolation of oxidized groundwater.


2018 ◽  
Vol 1 (2) ◽  
pp. 53-62
Author(s):  
Melly Mellyanawaty ◽  
Estin Nofiyanti ◽  
A Ibrahim ◽  
N Salman ◽  
N Nurjanah ◽  
...  

Society services activity in kitchen waste management system has been implemented to the owner of restaurant and catering work in Tasikmalaya City area. This activity has colaborated with Indonesian Catering Associations (APJI). The rapid growth of restaurant and catering activities has created serious problems of energy requirement, water, and solid waste disposal. Less information and limited area become the problems in handling of kitchen waste. A simple technique is needed to overcome the environmental problem which is caused by kitchen waste. The components of kitchen waste include vegetables, peelings, fruit skins, spoilt fruit, cooked and uncooked meat, bones, fats, egg-shells, bread and pastries, cooked food waste, etc. Due to a high organic content, bioconversion technologies such as anaerobic digestion are more suitable to handle the waste convert to biogas. It would be reducing the LPG usage. For the kitchen wastewater, grease trap as pre-treatment followed by a physical and biological process is one of a simple process which can produce the effluent in accordance with government standard. The activities were continued by the socialization of 3R program (reuse, reduce, recycle) by doing demo utilization of kitchen solid waste such as packing material, mineral water bottle is made a handicraft. Knowledge transfer run well and the enthusiasm of the participants in following the activity were very good.


2013 ◽  
Vol 69 (3) ◽  
pp. 672-679 ◽  
Author(s):  
I. Seco ◽  
M. Gómez Valentín ◽  
A. Schellart ◽  
S. Tait

Reliable prediction of time-varying pollutant loads in combined sewer systems during storm periods can aid better management of the release of pollution into natural environments as well as enhancing storage tank design. Better understanding of the behaviour of sewer sediments is crucial for the development of models that adequately describe the transport of in-sewer solids and accurately predict the changes in pollutant concentration within combined sewers during storm events. This paper reports on the results of a test programme to examine the erosion of highly organic sewer sediment under the application of time-varying shear stress. The tests were carried out with and without supplying oxygen, and varying simulated dry-weather periods. The aim was to investigate the behaviour of real in-sewer sediment with a high organic content (around 80%) in an attempt to improve prediction of the transport rates under the particular Mediterranean conditions of long dry-period/build-up and intense rainfall/wash-off, and understand how this environment affects the erosional resistance and subsequent sediment release. Results have been compared with previous work on lower organic content sewer sediments and artificial organic sediment.


2020 ◽  
Vol 1150 ◽  
pp. 122196
Author(s):  
Petr Kozlik ◽  
Katarina Molnarova ◽  
Tomas Jecmen ◽  
Tomas Krizek ◽  
Radoslav Goldman

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3292 ◽  
Author(s):  
Ye-Eun Lee ◽  
I-Tae Kim ◽  
Yeong-Seok Yoo

Water treatment sludge from algal blooms were analyzed and compared with general water treatment sludge as the pyrolysis temperature was varied from 300 °C to 900° C. Elemental analysis showed that the water treatment sludge in the eutrophication region has ~12% carbon content, higher than that (8.75%) of general water treatment sludge. X-ray diffraction (XRD) analysis of both types of sludge showed that amorphous silica changed to quartz and weak crystalline structures like kaolinite or montmorillonite were decomposed and changed into stronger crystalline forms like albite. Fourier transform infrared spectroscopy (FT-IR) peaks of humic/fulvic acid that indicated the affinity to combine with heavy metals disappeared above 700 °C. Toxicity characteristic leaching procedure (TCLP), conducted to determine the heavy metal leaching amount of pyrolyzed water treatment sludge, showed the lowest value of 5.7 mg/kg at 500 °C when the humic acid was not decomposed. At 500 °C, the heavy metal leaching ratio to the heavy metal content of high organic content water treatment sludge and low organic content water treatment sludge were 1.87% and 3.19%, respectively, and the water treatment sludge of higher organic content was more stable. In other words, pyrolysis of water treatment sludge with high organic content at 500 °C increases the inorganic matter crystallinity and heavy metal leaching stability.


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