scholarly journals Spatial variability of ammonium, nitrite and nitrate concentrations in water of Batang Arau River, West Sumatera, Indonesia

2020 ◽  
Vol 20 (4) ◽  
pp. 1484-1492
Author(s):  
Denny Helard ◽  
Shinta Indah ◽  
Michella Oktavia
Keyword(s):  
Spatial Variability ◽  
Anthropogenic Activities ◽  
Nitrogen Concentration ◽  
Monitoring Program ◽  
Quality Standard ◽  
Nitrite Concentration ◽  
Sampling Locations ◽  
Maximum Permissible Concentrations ◽  
Nitrate Concentrations ◽  
Nitrogen Concentrations

Abstract The objective of this study is to analyze the spatial variability of ammonia, nitrite, and nitrate concentrations along the Batang Arau River, one of the most important rivers in West Sumatera, Indonesia. The results showed that the ammonium, nitrite, and nitrate concentrations were in the range of 0.180–0.510 mg/L, 0.0–0.178 mg/L, and 0.675–1.165 mg/L, respectively. The ammonium and nitrate concentrations were still below the maximum permissible concentrations for the river water quality standard of class II established by the Regulation Governor of West Sumatera at all of the sampling locations, except at midstream for ammonium, while the nitrite concentration had exceeded the quality standard from midstream to downstream of the river. The increase of the nitrogen concentration was observed from upstream to downstream of the river. Spatial analysis shows significant differences in nitrogen concentrations were obtained between the upstream and the midstream of the Batang Arau River (p < 0.05) but were not observed between the midstream and the downstream. This indicates the effect of different anthropogenic activities along the river. Based on the obtained results, for an effective monitoring program of the nitrogen concentration along the Batang Arau River, reducing the sampling locations from eight to five could be implemented.

Nitrogen cycling in a Venezuelan tropical seasonally flooded forest: soil nitrogen mineralization and nitrification

1994 ◽  
Vol 10 (3) ◽  
pp. 399-416 ◽  
Author(s):  
Barrios E. ◽  
Herrera R.
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Ammonium Nitrogen ◽  
Wet Season ◽  
Flooded Forest ◽  
Nitrogen Concentrations ◽  
Minimum Stress ◽  
Seasonally Flooded

ABSTRACTSeasonally flooded forests represent a transition between terrestrial and aquatic ecosystems. The Mapire river, a tributary of the Orinoco river, floods its surrounding forests during the wet season (May–December). The soils are very acid and the total nitrogen concentration (0.1%) is only half that found in nearby soils flooded by Orinoco waters. Ammonium-nitrogen predominates in the soil during the flooded period while nitrate-nitrogen concentrations are higher in the dry period. Wide fluctuations in the inorganic nitrogen fractions did not considerably affect the annual course of soil nitrogen.The predominance of mineralization versus nitrification (56 and 5 μgsoil month−1respectively) and possibly the synchronization of nitrogen availability with plant demand could be considered as nitrogen conserving mechanisms.In synchrony with the hydrologic cycle, the seasonally flooded forest studied shows a nitrogencycle where inputs and accumulation are maximized when the system is under minimum stress (dry season). During flooding, the system enters a period of dormancy making minimal use of nutrient and energy to avoid or tolerate anaerobiosis.

scholarly journals The Fitness Advantage of Commercial Wine Yeasts in Relation to the Nitrogen Concentration, Temperature, and Ethanol Content under Microvinification Conditions

2013 ◽  
Vol 80 (2) ◽  
pp. 704-713 ◽  
Author(s):  
Estéfani García-Ríos ◽  
Alicia Gutiérrez ◽  
Zoel Salvadó ◽  
Francisco Noé Arroyo-López ◽  
José Manuel Guillamon
Keyword(s):  
Abiotic Factors ◽  
Nitrogen Concentration ◽  
Wine Yeast ◽  
Wine Industry ◽  
Wine Yeasts ◽  
Simple Method ◽  
Fitness Advantage ◽  
Yeast Strains ◽  
Industrial Strains ◽  
Nitrogen Concentrations

ABSTRACTThe effect of the main environmental factors governing wine fermentation on the fitness of industrial yeast strains has barely received attention. In this study, we used the concept of fitness advantage to measure how increasing nitrogen concentrations (0 to 200 mg N/liter), ethanol (0 to 20%), and temperature (4 to 45°C) affects competition among four commercial wine yeast strains (PDM, ARM, RVA, and TTA). We used a mathematical approach to model the hypothetical time needed for the control strain (PDM) to out-compete the other three strains in a theoretical mixed population. The theoretical values obtained were subsequently verified by competitive mixed fermentations in both synthetic and natural musts, which showed a good fit between the theoretical and experimental data. Specifically, the data show that the increase in nitrogen concentration and temperature values improved the fitness advantage of the PDM strain, whereas the presence of ethanol significantly reduced its competitiveness. However, the RVA strain proved to be the most competitive yeast for the three enological parameters assayed. The study of the fitness of these industrial strains is of paramount interest for the wine industry, which uses them as starters of their fermentations. Here, we propose a very simple method to model the fitness advantage, which allows the prediction of the competitiveness of one strain with respect to different abiotic factors.

scholarly journals Nitrogen for growth of stock plants and production of strawberry runner tips

Bragantia ◽  
2012 ◽  
Vol 71 (3) ◽  
pp. 394-399 ◽  
Author(s):  
Djeimi Isabel Janisch ◽  
Jerônimo Luiz Andriolo ◽  
Vinícius Toso ◽  
Kamila Gabriele Ferreira dos Santos ◽  
Jéssica Maronez de Souza
Keyword(s):  
Leaf Area ◽  
Nutrient Solution ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
Growth Period ◽  
Dry Matter Partitioning ◽  
Area Index ◽  
Camino Real ◽  
Nitrogen Concentrations ◽  
Crown Roots

The objective of this research was to determine growth and dry matter partitioning among organs of strawberry stock plants under five Nitrogen concentrations in the nutrient solution and its effects on emission and growth of runner tips. The experiment was carried out under greenhouse conditions, from September 2010 to March 2011, in a soilless system with Oso Grande and Camino Real cultivars. Nitrogen concentrations of 5.12, 7.6, 10.12 (control), 12.62 and 15.12 mmol L-1 in the nutrient solution were studied in a 5x2 factorial randomised experimental design. All runner tips bearing at least one expanded leaf (patent requested) were collected weekly and counted during the growth period. The number of leaves, dry matter (DM) of leaves, crown and root, specific leaf area and leaf area index (LAI) was determined at the final harvest. Increasing N concentration in the nutrient solution from 5.12 to 15.12 mmol L-1 reduces growth of crown, roots and LAI of strawberry stock plants but did not affect emission and growth of runner tips. It was concluded that for the commercial production of plug plants the optimal nitrogen concentration in the nutrient solution should be 5.12 mmol L-1.

Seasonal fluctuations in river bacteria as measured by multivariate statistical analysis of continuous cultures

1982 ◽  
Vol 28 (8) ◽  
pp. 959-975 ◽  
Author(s):  
Colin R. Bell ◽  
Maxine A. Holder-Franklin ◽  
Mervyn Franklin
Keyword(s):  
Statistical Analysis ◽  
Continuous Culture ◽  
Culture Medium ◽  
Nitrogen Concentration ◽  
Diversity Analysis ◽  
Seasonal Fluctuations ◽  
High Nitrogen ◽  
Continuous Cultures ◽  
Multivariate Statistical ◽  
Nitrogen Concentrations

Forty-eight continuous culture enrichments were performed on summer and winter water samples from two contrasting rivers. The cell output from each chemostat was dependant on the temperature and nitrogen concentration of each enrichment. The diversity of the populations from the continuous cultures, as assessed by species diversity analysis, was always greater than populations obtained on agar plates. However, the species isolated exclusively by continuous culture in these experiments were not unique to the chemostat. All of these species had been isolated at some time on plates directly. High nitrogen concentrations were found to decrease diversity. Populations sampled during the winter were influenced primarily by the concentration of nitrogen. Summer isolates were affected mainly by the temperature of the culture medium. The nutritional versatility of the population was not affected by enrichment of the continuous culture.

scholarly journals Achieving sustainable coastal environment in Langkawi, Malaysia

2017 ◽  
Author(s):  
Mazlin Mokhtar ◽  
Minhaz Farid Ahmed ◽  
Khai Ern Lee ◽  
Lubna Alam ◽  
Choo Ta Goh ◽  
...  
Keyword(s):  
Anthropogenic Activities ◽  
Sediment Quality ◽  
Pollution Index ◽  
Quality Standard ◽  
Coastal Environment ◽  
Coastal Pollution ◽  
Marine Biodiversity ◽  
Average Value ◽  
Spanish Mackerel ◽  
Coastal Marine

Despite many good policies and institutions, the coastal environment of Langkawi continues to deteriorate. This could be due to lack of effective governance as well as unregulated waste discharge. Evidences collected from the literature during 1996 to 2013 also revealed a significant increase in the concentrations of Zn (R2 = 0.78) and Pb (R2 = 0.12) in the sediment. This appears to be the result of large volume of terrestrial runoff that brings these metals originating from extensive anthropogenic activities. It is a vital indicator of coastal pollution. It is a matter of concern that in many cases Pb concentration in the sediment exceeded the world average value 20 μg/g as well as Canadian Interim Sediment Quality Standard of 35 μg/g for the coastal areas. Similarly, the metal pollution index (MPI) measured over a period of 2007 to 2009 in fish also indicated an increasing trend of pollution in Langkawi. The maximum MPI value (4.87) was recorded in Spanish mackerel. Since pollution of coastal environment has serious implications for marine biodiversity and health of seafood consumers, measures are required to address this problem. Use of constructed wetland might be effective in reducing the coastal pollution as this will filter the effluent and waste before their mixing with the coastal water. Furthermore, enabling the stakeholders to play the environmental stewardship role will ensure better governance of coastal ecosystem and effective implementation of policies, envisaging an improved monitoring of waste/effluent discharge into the coastal marine environment. These measures are among the actions necessary for achieving a sustainable coastal environment of Langkawi.

scholarly journals Microplastics Determination in the Rivers with Different Urbanisation Variances: A Case Study in Kuching City, Sarawak, Malaysia

2020 ◽  
Vol 10 (2) ◽  
pp. 116-125
Author(s):  
Georgina Johnson ◽  
Wen San Hii ◽  
Samuel Lihan ◽  
Meng Guan Tay
Keyword(s):  
Anthropogenic Activities ◽  
River System ◽  
Anthropogenic Activity ◽  
Domestic Waste ◽  
Shape Identification ◽  
Suburban Areas ◽  
Sampling Locations ◽  
The Relationship ◽  
Main Factor

The presence of microplastics in aquatic systems is mainly due to the anthropogenic activities such as domestic waste dumping. Undeniably, rivers either in urban or suburban areas are always a waste dumpling sites from the surrounding residences. Thus, the purpose of this study was to determine the relationship between microplastic abundance and different degree of urbanization across Kuching in Sarawak. Three sampling locations with different degrees of urbanisation had been studied across Kuching. A total of 137 pieces of microplastics were collected along the study and analysed using stereoscopic microscope for the shape identification and FTIR spectrophotometer for functional groups present in the microplastics. Filament was the most abundant microplastics shape found, whereas the IR results showed that ethylenevinylacetate (9%), polyamides or nylon (15%), polypropylene (42%), poly(methylmethacrylate) (16%) and polystyrene (18%) were found in the study. The most abundant microplastics in the water samples was polypropylene (42%), whereas ethylenevinylacetate (9%) was the least. The degree of urbanisation does not directly relate to the microplastic present in the river system in Kuching City, but the anthropogenic activity is the main factor that affecting the microplastic abundance in the river.   Keywords: anthropologenic activity, FTIR, microplastics, polymer identification, urban, sub-urban

scholarly journals Comparison of the nest materials of Polistes Gallicus (L.), Polistes dominulus (Christ) and Polistes nimpha (Christ) (Hymenoptera: Vespidae)

2012 ◽  
Vol 64 (3) ◽  
pp. 1079-1084 ◽  
Author(s):  
Nil Bagriaçik
Keyword(s):  
Elemental Composition ◽  
Nitrogen Concentration ◽  
Average Thickness ◽  
Polistes Dominulus ◽  
Ecological Conditions ◽  
Nitrogen Concentrations ◽  
Nest Materials ◽  
Physical Features

The aim of this study was to determine and compare the nest materials and some physical features and elemental composition of the nests of Polistes gallicus (L.), Polistes dominulus (Christ) and Polistes nimpha (Christ) collected in similar ecological conditions. The nest architectures of the three species were similar. In the P. gallicus nest, the average thickness of the fibers was 5.73 ?m, the nitrogen concentration was 26.14%, and percentages of the fibers and saliva were 77% and 23%, respectively. In the P. dominulus nest, the average thickness of the fibers was 8.7 ?m, and the nitrogen concentration was 27.42%; the percentages of fiber and saliva were 78% and 22%, respectively. In the P. nimpha nest, the average thickness of the fibers was 9.04 ?m, the nitrogen concentration was 25.82%, and the percentages of the fiber and saliva were 42% and 58%, respectively. There were differences in the amount of saliva and nitrogen concentrations.

scholarly journals Mycelial biomass cultivation of Lentinus crinitus

2020 ◽  
Vol 36 (6) ◽  
Author(s):  
Itaruã Machri Colla ◽  
Olavo Bilac Quaresma de Oliveira Filho ◽  
Janyeli Dorini Silva de Freitas ◽  
Míria Benetati Delgado Bertéli ◽  
Giani Andrea Linde ◽  
...  
Keyword(s):  
Soybean Meal ◽  
Nitrogen Concentration ◽  
Fungal Growth ◽  
Malt Extract ◽  
Biomass Growth ◽  
Mycelial Biomass ◽  
Protein Nitrogen ◽  
Temperature Growth ◽  
Nitrogen Concentrations ◽  
High Concentrations

Lentinus crinitus is a medicinal basidiomycete, little studied regarding the basic cultivation conditions, which is used in bioremediation and consumed by native Indians from the Brazilian Amazon. Also, it produces a fungal secondary metabolite panepoxydone that has been described as an essential regulator of the inflammatory and immune response. This study aimed to evaluate basic conditions of temperature, pH, and nitrogen concentration and source in the cultivation of L. crinitus mycelial biomass. In order to evaluate fungal growth temperature, 2% malt extract agar (MEA) medium, pH 5.5, was utilized from 19 to 40 °C. For pH, MEA had pH adjusted from 2 to 11 and cultivated at 28 °C. Urea or soybean meal was added to MEA to obtain final concentration from 0.5 and 16 g/L of nitrogen, pH of 5.5, cultivated at 28 °C. The best temperature growth varies from 31 to 34 ºC and the optimal one is 32.7º C, and the best pH ranges from 4.5 to 6.5 and the optimal one is 6.1. Protein or non-protein nitrogen concentration is inversely proportional to the mycelial biomass growth. Nitrogen concentrations of 2.0 g/L soybean meal and urea inhibit mycelial biomass growth in 11% and 12%, respectively, but high concentrations of 16.0 g/L nitrogen inhibit the growth in 46% and 95%, respectively. The fungus is robust and grows under extreme conditions of temperature and pH, but smaller adaptation with increasing nitrogen concentrations in the cultivation medium, mainly non-protein nitrogen.

scholarly journals Modelling of nitrogen concentrations in water from drained peat soils

2019 ◽  
Vol 69 (3) ◽  
pp. 288-297 ◽  
Author(s):  
Anatoli Vassiljev ◽  
Ivar Annus ◽  
Nils Kändler ◽  
Katrin Kaur
Keyword(s):  
Water Quality ◽  
Significant Source ◽  
Agricultural Activity ◽  
Large Share ◽  
Peat Soils ◽  
Nitrate Concentrations ◽  
Nitrogen Concentrations ◽  
Improve Water Quality ◽  
Model Water

Abstract In addition to traditional sources, drained peat soils have been found to be a significant source of nitrogen in Estonia. As a result, supplementary measures are required to improve water quality in rivers. Modelling is a widespread method to select means for improving water quality. At present, modelling of nitrogen in rivers has been concentrated on the influence of agricultural activity. However, drained peat can increase nitrogen concentrations even without fertilization and farming activities. This investigation describes the attempt to model water quality in the watershed with a large share of drained peat soils. The results showed a good alignment between measured and modelled nitrate concentrations using the MACRO and the SOILN for MACRO models. Some measures to improve water quality were tested using these models.

Effects of Submergence and Nitrogen Concentration on the Resources Utilization of Alternanthera philoxeroides

2013 ◽  
Vol 864-867 ◽  
pp. 239-242
Author(s):  
Wen Juan Ding ◽  
Hua Yong Zhang ◽  
Fang Juan Zhang
Keyword(s):  
Water Level ◽  
Biomass Allocation ◽  
Invasive Plant ◽  
Nitrogen Concentration ◽  
Soluble Sugar ◽  
Nitrogen Pollution ◽  
Water Bodies ◽  
Alternanthera Philoxeroides ◽  
Negative Effects ◽  
Nitrogen Concentrations

This study examined the effects of submergence and nitrogen concentration on biomass allocation and nutrients utilization of an invasive plant Alternanthera philoxeroides. In the experiment, A. philoxeroides was applied to two water level treatments (0 and 25cm above the surface) across with two nitrogen concentrations (0 and 10 mg/l N). The results showed that submergence decreased leaf fraction and increased stem fraction, but high N changed this situation. In submergence, high N increased leaf fraction but decreased stem fraction due to leaves survival and maintenance. Submergence decreased root fraction and the content of soluble sugar in stem. The results suggested that high N concentration could counteract the negative effects of submergence. Therefore, the risk of A. philoxeroides invasion might be enhanced by nitrogen pollution in fluctuating water bodies, and should be attention intensely.

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