Effect of carbon/nitrogen ratio manipulation in feed supplements onArtemiaproduction and water quality in solar salt ponds in the Mekong Delta, Vietnam

2013 ◽  
Vol 45 (12) ◽  
pp. 1906-1912 ◽  
Author(s):  
Lulijwa Ronald ◽  
Gilbert Van Stappen ◽  
Nguyen Van Hoa ◽  
Patrick Sorgeloos
2020 ◽  
Vol 8 (2) ◽  
pp. 140-145
Author(s):  
Prajina Neupane ◽  
Madhusudhan Adhikari ◽  
Manita Kumari Thapa ◽  
Astha Kiran Pandeya

Bio-floc technology is the blue revolution in aquaculture & new technique of enhancing water quality & utilizing feed wastes in the aquaculture system. It follows the concept of conversion of ammonium in addition to organic nitrogenous wastes into bacterial biomass in where heterotrophic bacterial growth is stimulated & nitrogen uptake through the production of microbial proteins is promoted by the addition of carbohydrates to the pond. Nitrogen generated by uneaten feed and excreta of cultured organisms is converted into proteinaceous feed available for those same organisms. This technique recycles nutrients & nitrogenous wastes by maintaining a high carbon: nitrogen ratio and provides essential & higher quality nutrition to the shrimps & fishes in achieving fast growth, lesser FCR & possibility to prevent diseases. Water requirement in BFT is extremely less & it is advantageous than the conventional system where there is continuous water & nutrient recycling, lower FCR. On the other hand, many challenges are existing in practicing bio-floc in Nepal as it requires frequent pond monitoring by the technical manpower. The choice of carbon source should be made wisely and correctly as the performance of fish and water quality in the bio-floc ponds depend highly upon carbon source. Further, vitamins required for fish may not be produced by microbes thus needed to identify them and supply through the feed. However, the practice of bio-floc technology will be proven worth for farmers in Nepal. Int. J. Appl. Sci. Biotechnol. Vol 8(2): 140-145  


2013 ◽  
Vol 8 (2) ◽  
pp. 159-178 ◽  

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.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 491
Author(s):  
Kazuki Kano ◽  
Hiroaki Kitazawa ◽  
Keitaro Suzuki ◽  
Ani Widiastuti ◽  
Hiromitsu Odani ◽  
...  

Effects of corn steep liquor (organic fertilizer, OF) and conventional chemical fertilizer (CF) on the growth and yield of bok choy (Brassica rapa var. chinensis) in summer and autumn hydroponic growing systems were compared. When OF and CF were applied with the same amount of total nitrogen in summer cultivation, there was no significant difference between yields; however, the growth rate in OF was slower than in CF. When OF was applied with twice the amount of nitrogen in CF (OF2), bok choy growth and yield were significantly inhibited in summer cultivation, likely owing to dissolved oxygen deficiency and different rates of nitrification and nitrogen absorbance by the plant root. Although the contents of potassium, calcium, and magnesium in bok choy showed no difference among the three treatments in both cultivation seasons, the carbon/nitrogen ratio tended to be higher in OF and OF2 than in CF. Lower nitric acid and higher ascorbic acid content was found in OF and OF2 than in CF. Overall, our results suggest that a comparable yield is expected by using the same nitrogen amount with a conventional recipe of chemical fertilization in autumn cultivation. However, further improvement of hydroponic management is needed in summer cultivation.


RSC Advances ◽  
2020 ◽  
Vol 10 (39) ◽  
pp. 23212-23220
Author(s):  
Jian Xu ◽  
Xiawei Liu ◽  
Jiaolong Huang ◽  
Manqi Huang ◽  
Tao Wang ◽  
...  

Schematic diagram of RDCWs system and proposed mechanisms for nitrate removal.


2015 ◽  
Vol 5 ◽  
pp. 46-54 ◽  
Author(s):  
Mélida del Pilar Anzola-Rojas ◽  
Samantha Gonçalves da Fonseca ◽  
Cynthia Canedo da Silva ◽  
Valeria Maia de Oliveira ◽  
Marcelo Zaiat

1972 ◽  
Vol 50 (11) ◽  
pp. 2097-2102 ◽  
Author(s):  
R. Hall ◽  
H. Ly

The development of microsclerotia of Verticillium dahliae from a few swollen hyaline cells on a hypha to a multicellular, pigmented "mature" structure is described and illustrated. A method for quantitatively estimating the amount of pigmented microsclerotial material in pure cultures was developed to study quantitative relations between mycelial growth and production of microsclerotial material in media containing different concentrations of glucose. At low glucose concentrations (0.6 to 10 mg/ml) microsclerotial material continued to increase after total dry weight of the cultures had reached a maximum, suggesting conversion of hyaline to pigmented material. At high glucose concentrations (20 to 60 mg/ml) the patterns of increase in total dry weight, microsclerotial material, and hyaline material were similar over a 4-week incubation period. Maximum production of both pigmented and hyaline materials occurred at a glucose concentration of 30 mg/ml (carbon/nitrogen ratio of 50/1).


1970 ◽  
Vol 23 (2) ◽  
pp. 159-161 ◽  
Author(s):  
ANM Fakhruddin ◽  
M Alamgir Hossain

Aromatic pollutants like m-chlorophenol is toxic to the environment and chlorophenol containing a metachlorine are more persistent under aerobic conditions than compounds lacking a chlorine substituent in positions meta to hydroxyl group. Therefore, it should be removed effectively from the environment. In order to increase the degradative activity, the optimum conditions for m-chlorophenol degradation by Pseudomonas putida CP1, some physicochemical conditions like pH, temperature and carbon nitrogen ratio for the growth and degradation of most persistent monochlorophenol, m-chlorophenol by the organism was optimised. The pH optimum for m-chlorophenol degradation by the bacterium was between pH 6.5 and 7.0 and the temperature optimum was 30°C for removal activity. Carbon : nitrogen (C:N) ratio of 3:1 was found best for effective removal of chemical oxygen demand (COD) and m-chlorophenol by the bacterium. Keywords: m-Chlorophenol degradation, Pseudomonas putida CP1, Chemical oxygen demand (COD)DOI: http://dx.doi.org/10.3329/bjm.v23i2.884  Bangladesh J Microbiol, Volume 23, Number 2, December 2006, pp 159-161


Sign in / Sign up

Export Citation Format

Share Document