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TONNY BACHTIAR
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Agriculture, Biological Sciences & Forestry Earth & Planetary Sciences Education

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Journal : JOURNAL OF COASTAL DEVELOPMENT

 1 
PRELIMINARY STUDY OF THE POTENCY OF SEDIMENTATION RATE IN BANJIR KANAL TIMUR SEMARANG COASTAL WATERS Tonny Bachtiar
JOURNAL OF COASTAL DEVELOPMENT Vol 6, No 2 (2003): Volume 6, Volume 2, Year 2003
Publisher : JOURNAL OF COASTAL DEVELOPMENT

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Abstract

Five sets of sediment traps were installed for thirty days (Oct.- Nov. 1999) in Banjir Kanal Timur Semarang coastal waters to examine the potency of sedimentation rate. Two sediment traps were lost in the second week of measurement. Based on the average data of three sets of sediment traps, the potency of sedimentation rate in Banjir Kanal Timur Semarang coastal waters was 6.10 cm/month. The result did not reflect the fact of the field condition. Based on the correction made  on the input of suspended discharge into Banjir Kanal Timur Semarang coastal waters and the average area of sediment distribution, the potency of sediment rate in Banjir Kanal Timur Semarang coastal water during transition of dry season to rainy season was 0.35 cm/month.
PRELIMINARY STUDY ON POTENCY OF COPROSTANOL AND COLIFORM BACTERIA IN SEMARANG COASTAL AREA Tonny Bachtiar
JOURNAL OF COASTAL DEVELOPMENT Vol 6, No 1 (2002): Volume 6, Number 1, Year 2002
Publisher : JOURNAL OF COASTAL DEVELOPMENT

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Abstract

Fecal coliform bacteria have been widely used as a biological indicator of sewage (domestic waste) pollution. However, as a biological indicator in urban coastal waters, it has disadvantage, in particular because of increased volume of industrial wastes that are toxic and heated, increase of salinity, and low dissolved oxygen. These conditions may affect the growth rate of most bacteria, including fecal coliform bacteria that becomes under representative in sewage pollution  in urban coastal waters. It is necessary to find alternative indicator that can be used to better understand the sewage pollution in urban coastal waters. Many researchers have proposed coprostanol as a chemical indicator of sewage pollution. To understand the existence of coprostanol and coliform bacteria, a preliminary study has been done on water and sediment samples from the river, river mouth, and seawater of Banjir Kanal Timur Semarang coastal waters. The results showed that coprostanol could be detected in sediment from all sites, on the other hand coliform bacteria decreased with the increase of salinity, and were not detected in the seawater.
NATURAL BIODEGRADATION OF COPROSTANOL IN AN EXPERIMENTAL SYSTEM OF THREE ENVIRONMENTAL CONDITIONS OF JAKARTA WATERS, INDONESIA Tonny Bachtiar; Agus Sabdono
JOURNAL OF COASTAL DEVELOPMENT Vol 8, No 1 (2004): Volume 8, Number 1, Year 2004
Publisher : JOURNAL OF COASTAL DEVELOPMENT

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Abstract

Constraint of using bio-indicator (coliform bacteria) as an indicator of domestic (sewage) pollution in the environment with high environmental stress encourages the discovering of other alternate indicators. Coprostanol has been proposed as a chemical indicator of domestic waste pollution, but most research on were conducted in the temperate (high latitude) region. The persistence of coprostanol in tropical region, especially in Indonesia, is still very poor. It is very important to understand the persistence of coprostanol in the nature, as one of the requirements to propose coprostanol as an alternate indicator of domestic waste pollution. In order to better understand the natural biodegradation of coprostanol, experimental system on three environmental conditions (river, river mouth, and coastal waters) was conducted. In April 2004, samples of water and surface bottom sediments were collected from each environmental condition in duplicate. Before the samples were put into aerated and non-aerated aquaria, about 35-40 g of surface bottom sediments were taken to analyze the initial concentration (C0) of coprostanol. The sediments were subsequently sampled from each aquarium within a certain interval day to analyze the concentration of coprostanol (C10, C20, and C40). The results showed that aeration plays not an important role in natural biodegradation of coprostanol. In average, the highest rate of coprostanol biodegradation is 0.438 μg/g day-1 in non aerated coastal water environment, where as the lowest was found in the non aerated river mouth environment (0.021 μg/g day-1). Since coprostanol was degraded very slowly, and could be detected in the sediments of three environmental conditions, coprostanol has an excellent potency to be used as an alternate indicator of domestic wastes.
VERTICAL EXISTENCE OF COPROSTANOL IN A SEDIMENT CORE FROM SEMARANG COASTAL WATERS, CENTRAL JAVA, INDONESIA Tonny Bachtiar
JOURNAL OF COASTAL DEVELOPMENT Vol 7, No 3 (2004): Volume 7, Number 3, Year 2004
Publisher : JOURNAL OF COASTAL DEVELOPMENT

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Abstract

Coprostanol has been proposed as an indicator of domestic (sewage) pollution by researchers because constraint of using coliform bacteria as the indicators of domestic pollution in the environment with high environmental stress, such as urban coastal waters. Increasing the volume of industrial wastes, toxic and heated, the changing of water salinity from low (freshwater) to high (sea water), and  decreasing of dissolved oxygen (DO) in the waters, are the constrain factors of bacteria growth. How ever, all the researches have been done in the temperate (high latitude) regions. Information existence of coprostanol in tropical region, especially in Indonesia is still very poor. To understand the existence of coprostanol in the sediments, one core sediment sample (60 cm) was collected from Semarang coastal water adjacent to Banjir Kanal Timur which is the main drainage system of the East Semarang municipal district in Central Java by using a small gravity corer in July 2001. The core sediment sample was divided into 12 sections (5 cm each) for analyzing the concentration of coprostanol, grain size, and TOC. The result shows that coprostanol could be detected in all sample sections (vary from 1.06 to 2.94 mg/g). Coprostanol has significant positive correlation with TOC, but not significant with grain size. Coprostanol has very significant negative correlation with the depth of core. Based on the potency of sedimentation rate analysis on Banjir Kanal Timur Semarang coastal waters (0.35 cm/month), the 60 cm core sediment was predicted as a result of 14 –16 year sedimentation. All of these facts show that coprostanol has an excellent persistence in the sediment of tropical environment, and reflect that coprostanol has a potency as an alternative indicator of domestic waste pollution in urban tropical coastal waters. age��G'p� x� environments by Indonesian scientists. This is mainly because of the lack of knowledge in the field of deep-sea microbiology in Indonesia. 
Co-Authors Agus Sabdono HANS- PETER GROSSART Meinhard Simon Ocky Karna Radjasa TORBEN MARTENS