Environmental significance of atrazine in aqueous systems and its removal by biological processes: an overview

2013 ◽  
Vol 8 (2) ◽  
pp. 159-178 ◽  
Keyword(s):  
Drinking Water ◽  
Ground Water ◽  
Water Environment ◽  
Biological Processes ◽  
Biological Degradation ◽  
Environmental Significance ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Living Organisms

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides in the World. Due to its extensive use, long half-life and various toxic properties, it has very high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water whereas permissible limit of atrazine is in ppb level in drinking water. As per Indian standard there should not be any pesticide present in drinking water. Among many other treatment processes available, Incineration, adsorption, chemical treatment, phytoremediation and biodegradation are the most commonly used ones. Biological degradation of atrazine depends upon various factors like the operating environment, external carbon and nitrogen sources, carbon/ nitrogen ratio (C/N), water content and the bacterial strain. Although, general atrazine degradation pathways are available, the specific pathways in specific conditions are not yet clearly defined. In this paper extensive review has been made on the occurrence of atrazine in surface and ground water bodies, probable sources and causes of its occurrence in water environment, the toxicity of atrazine on various living organisms and its removal by biological processes.

scholarly journals A new chemical compound with an unusual ratio of number of carbon and nitrogen atoms – C(N12): quantum-chemical modelling

RSC Advances ◽  
2021 ◽  
Vol 11 (57) ◽  
pp. 35974-35981
Author(s):  
Denis V. Chachkov ◽  
Oleg V. Mikhailov
Keyword(s):  
Chemical Compound ◽  
Quantum Chemical ◽  
Nitrogen Compounds ◽  
Carbon And Nitrogen ◽  
Chemical Modelling ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio

The possibility of the existence of tetracyclic carbon–nitrogen compounds having the unusual carbon : nitrogen ratio 1 : 12, which is unknown for these elements at the present, was shown.

scholarly journals Study of Some Physical & Chemical Characteristic Properties of Ground Water in the Villages of Veeraghattam and Palakonda Mandals in Srikakulam District, A.P, India

2015 ◽  
Vol 10 (2) ◽  
pp. 610-618 ◽  
Author(s):  
Nadikatla Kumar ◽  
Mushini Rao ◽  
M. P. S. Krishna
Keyword(s):  
Drinking Water ◽  
Ground Water ◽  
Chemical Constituents ◽  
Chemical Characteristic ◽  
Underground Water ◽  
Human Beings ◽  
Physico Chemical ◽  
Living Organisms ◽  
Physical And Chemical

Human beings require potable water for drinking to keep them healthy. Clean, safe and adequate fresh water is vital to the survival of all living organisms. Drinking water affects the health of human beings due to the presence of various dissolved chemical constituents. Problems arising out of chemical constituents in drinking water are different from the problems of microbial contamination. Therefore, consumers should have at least minimum knowledge on quality of drinking water. People across the world depend on ground water for drinking. Ground water is a major source, so based on the importance of the matter; a research topic is taken up on the assessment of quality of groundwater in the selected areas of villages in Veeraghattam and Palakonda Mandals of Srikakulam District, Andhra Pradesh. This preliminary study assessed the quality of physical and chemical characteristic properties of underground water in the selected locations of 40 villages in Veeraghattam and 39 villages in Palakonda Mandals of Srikakulam District. Some physico chemical characteristic parameters are estimated in the samples and the results obtained are compared with the available standard values such as WHO and BIS.

Effect of carbon, nitrogen and physico-chemical factors on patulin production in Penicillium expansum

2018 ◽  
Vol 7 (2) ◽  
pp. 57-63
Author(s):  
Aouatef Mansouri Mansouri ◽  
Miloud Elkarbane ◽  
Mohamed Ben Aziz ◽  
Hasna Nait M’Barek ◽  
Majida Hafidi ◽  
...  
Keyword(s):  
Culture Media ◽  
Effective Means ◽  
Great Influence ◽  
Nitrogen Sources ◽  
Medium Effect ◽  
Penicillium Expansum ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio

Environmental and nutritional factors play important roles in regulating production of mycotoxins. Few studies have been reported on the biosynthesis of patulin mycotoxin and the mechanisms that involve its biosynthesis in Penicillium expansum. Here, we investigated the effects of two culture media, pH, temperature, carbon and nitrogen sources and effect of carbon/nitrogen ratio on mycotoxin biosynthesis by P. expansum isolated from Moroccan cereals. It was found that pH and temperature had great influence on patulin production. Results also showed that carbon and nitrogen sources influ-enced patulin biosynthesis significantly in this strain. L-glutamate was optimized as important nitrogen source in synthetic culture medium. Effect of carbon/nitrogen ratio was evaluated which indicated the dependence of patulin production on this ratio. These results will provide useful information to better understand the regulatory mechanisms of patulin biosynthesis, and be helpful in developing effective means for controlling a mycotoxin contam-ination of foods and feeds.

The Carbon-Nitrogen Ratio of Soil Organic Matter

1930 ◽  
Vol 20 (3) ◽  
pp. 348-354 ◽  
Author(s):  
W. McLean
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Arable Soils ◽  
Grassland Soils ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Soil Climate ◽  
Range Of Variation

1. The average carbon-nitrogen ratio for fifty British soils from widely distributed areas approximates to the figure 10: 1 given by other investigators. The range of variation is from 6·5 to 13·5: 1. Sixteen foreign samples gave C/N ratios varying from 2·0 to 23·0: 1.2. Soils from limited areas, whether high or low in organic carbon, give approximately constant ratios, but these ratios vary from place to place according to soil, climate, etc. It is suggested that the C/N ratios may be specific.3. The C/N ratios of arable soils do not differ appreciably from those of grassland soils. The percentages of carbon and nitrogen are somewhat higher in the grassland samples than in the arable samples.

THE EFFECT OF NUTRIENTS AND ENVIRONMENT ON SYNNEMATA FORMATION OF STILBELLA THERMOPHILA

1967 ◽  
Vol 13 (4) ◽  
pp. 351-360 ◽  
Author(s):  
K. K. Al-Hassan ◽  
C. L. Fergus
Keyword(s):  
Mycelial Growth ◽  
Nutrient Concentration ◽  
Basal Medium ◽  
Nitrogen Sources ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
The Media ◽  
Nitrogen Ratio ◽  
Exogenous Supply

Stilbella thermophila Fergus was grown on a chemically denned medium of D-glucose, KNO3, MgSO4, KH2PO4, agar, and microelements to determine the effect of environment and nutrition on growth and synnemata production. An exogenous supply of thiamine stimulated growth markedly on pyridine-purified agar, but both thiamine and biotin were required for synnemata to form. Pyrimidine was the effective moiety, not thiazole. S. thermophila grew on a large number of carbon and nitrogen compounds substituted singly into the basal medium, but synnemata formed on less than half of such media. Sucrose did not inhibit synnemata formation with glucose present, but no synnemata formed with sucrose in the medium even with a number of different nitrogen sources. Synnemata production followed chance mold contamination on a few of the media that normally did not allow their production. The carbon–nitrogen ratio significantly affected synnemata formation. So did pH, concentration of phosphate buffer, and temperature. At suboptimal temperatures, reduced synnemata, or only loose bundles of conidiophores, formed. Light was not required for synnemata initiation nor for maturation. Synnemata formation occurred over a narrower range of temperature, pH, vitamin concentration, nutrient concentration, and nutrient spectrum (carbon and nitrogen sources) than did mycelial growth.

Influence of microorganisms upon the carbon-nitrogen ratio in the soil

1924 ◽  
Vol 14 (4) ◽  
pp. 555-562 ◽  
Author(s):  
Selman A. Waksman
Keyword(s):  
Organic Matter ◽  
Surface Soil ◽  
Plant Residues ◽  
Silt Loam ◽  
Carbon And Nitrogen ◽  
Decomposition Of Organic Matter ◽  
Original Plant ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Carbon And Nitrogen Content

Various investigations on the decomposition of organic matter in the soil have brought out the fact that there exists a more or less constant ratio between the carbon and nitrogen content of the soil, whatever the ratio between these elements in the organic matter originally added to the soil. This ratio varies from 8: 1 to 12: 1, i.e. for every 8 to 12 parts of carbon, there exists in the soil one part of nitrogen; the average ratio is about 10 to 1. Brown and O'Neal (1923), for example, found that the ratio of the carbon to the nitrogen in a Carrington loam is 12: 1 to 13: 1, while, in the case of a Tama silt loam, the ratio may go down to 10: 1. According to Sievers (1923), the ratio of carbon to nitrogen in the soil is about 11·6: 1. Russell (1923) stated that, although there is about 40 times as much carbon as nitrogen in the original plant residues, the ratio will drop down to 10 to 1, before these residues have been very long in the soil. This ratio seemed to be in a stable position, for which no explanation could be suggested. Fraps (1922) found the ratio of carbon to nitrogen in the surface soil to be 9·2: 1 and in the subsoil 8·3: 1; he suggested, therefore, to judge the percentage of organic carbon in the soil from the percentage of nitrogen present.

Soil fertility changes in a red-brown earth under irrigated pastures. I. Changes in organic carbon/nitrogen ratio, Cation exchange capacity and pH

1966 ◽  
Vol 17 (3) ◽  
pp. 317 ◽  
Author(s):  
AJ Rixon
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Fertility ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Soil Horizon ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio

Organic matter and soil fertility changes under irrigated pastures were followed for 5 years at Deniliquin, N.S.W. The effects of three annual pastures and of three perennial pastures were studied. Four years after their establishment an organic matter layer (mat) had formed under all pastures, and after its formation there was no further accumulation of organic carbon in the 0–3 in. soil horizon. The mean annual increase in organic carbon was 625 lb/acre under annual pastures and 1146 lb/acre under perennial pastures. The carbon/nitrogen ratios of both soil and mats, and the relationships of both organic carbon and nitrogen to the cation exchange capacity of the mats, were similarly affected by the annual and perennial pastures. The heterogeneous nature of the mats obscured any differences in their carbon/nitrogen ratios, which ranged from 12.8 to 22.0. The cation exchange capacity of the 0–3 in. soil horizon remained unchanged. The cation exchange capacity of the organic matter of the mats was approximately 100 m-equiv./100 g. After mat formation the underlying soil had a pH of approximately 6.0 under clovers and 6.5 under ryegrasses. The pH values of the mats ranged from 5.9 to 6.6.

Biological Characteristics for Mycelial Growth of Agaricus bisporus

2014 ◽  
Vol 508 ◽  
pp. 297-302 ◽  
Author(s):  
Yan Ma ◽  
Chu Yu Guan ◽  
Xian Jun Meng
Keyword(s):  
Growth Regulators ◽  
Agaricus Bisporus ◽  
Mycelial Growth ◽  
Nitrogen Sources ◽  
Biological Characteristics ◽  
Mycelium Growth ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
White Button Mushrooms

The biological characteristics of Agaricus bisporus mycelia were reported in this study. Biological characteristics of mycelium growth, including carbon source, nitrogen source, carbon-nitrogen ratio, temperature, pH and growth regulators, were investigated. The results indicated that the optimum carbon and nitrogen sources for mycelial growth were glucose and yeast extract fermentation, respectively. The optimum carbon-nitrogen ratio of culture was 20:1～30:1; the optimum temperature was 22～24°C and the optimum pH was 7.0～7.5. Analysis of growth regulators revealed that VC and VB1 were essential in promoting the mycelial growth of white button mushrooms.

Effect of Hydrogen Peroxide on soil Organic Matter

1931 ◽  
Vol 21 (2) ◽  
pp. 251-261 ◽  
Author(s):  
W. McLean
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Second Phase ◽  
Carbon And Nitrogen ◽  
Carbohydrate Complex ◽  
Carbon Compounds ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Two Phases

1. Six per cent. peroxide is found to be unsuitable as a reagent for the determination of the “degree of humification” of soil organic matter, as it oxidises not only compounds containing carbon and nitrogen but also a varying amount of a substance containing carbon but no nitrogen, this amount depending on the volume of reagent used and the total amount of carbon originally present in the quantity of soil employed.2. There are apparently two phases in the attack of peroxide on soil organic matter. In the first phase, material containing carbon and nitrogen is oxidised, whilst in the second phase the material oxidised consists solely of nitrogen-free carbon compounds.3. By the use of 3 per cent. peroxide (2 per cent, or less may be preferable for some soils) the attack on soil organic matter can be restricted to the first phase. The material thus oxidised appears to be built up by the association of a protein complex with a carbohydrate complex of high carbon content. Its carbon-nitrogen ratio is about 10:1.

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