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Total Ammonia Nitrogen (total + ammonia_nitrogen)

Distribution by Scientific Domains

Earth and Environmental Science	90%

Selected Abstracts

Settling velocity and total ammonia nitrogen leaching from commercial feed and faecal pellets of gilthead seabream (Sparus aurata L. 1758) and seabass (Dicentrarchus labrax L. 1758)

AQUACULTURE RESEARCH, Issue 15 2009
María Asunción Piedecausa
Abstract The physico-chemical characteristics of particulate wastes of Sparus aurata and Dicentrarchus labrax were investigated. Changes in the dimensions, settling velocity and total ammonia nitrogen (TAN) leached from commercial feed pellets were investigated after soaking. Also, the settling velocity and TAN leached from faecal pellets of these fish were assessed at 15 and 25 °C. The settling velocity of feed pellets was influenced positively by pellet weight and negatively by immersion length as a result of changes in pellet dimensions after soaking. The settling velocity of faecal pellets was determined by pellet weight. The experimental design did not allow identification of any consistent effect of water temperature on settling velocity. Total ammonia nitrogen leaching over time from feed and faecal pellets was successfully explained by means of a first-order kinetic equation. For feed pellets, water temperature significantly affected the speed of the process and the time at which the maximum TAN leached was reached, but did not influence the maximum TAN leached. Leaching was related to feed pellet size, and so the smaller the pellet, the higher the leaching. Total ammonia nitrogen leaching from faecal pellets was greater per unit weight than in feed pellets. However, neither water temperature nor fish species influenced TAN leaching from faeces. [source]

Effect of settled sludge on dissolved ammonia concentration in tanks used to grow abalone (Haliotis midae L.) fed a formulated diet

AQUACULTURE RESEARCH, Issue 2 2009
Rowan D Yearsley
Abstract The relative contribution that solid waste or ,sludge', which accumulates at the bottom of abalone (Haliotis midae L.) tanks, makes to dissolved ammonia has not been established. Sludge was allowed to accumulate in 10 fully stocked abalone tanks, fed a formulated feed (Abfeed®; Marifeed, South Africa), for 24 days. Sludge was subsequently siphoned from five of these tanks. Total ammonia nitrogen (TAN) production and toxic, free ammonia nitrogen (FAN) were recorded in the tanks from which sludge was removed and compared with those from which sludge was not removed over the subsequent 50 h. Tanks with neither abalone nor sludge present were used as a control. The mean production of TAN (±standard deviation) was an average of 44% higher in tanks from which sludge was not removed compared with those from which it was, indicating that the sludge was a significant contributor to dissolved ammonia in the tanks. The toxic FAN concentrations were correspondingly higher in tanks with sludge present (2.3±0.3 ,L,1) compared with cleaned tanks (1.9±0.1 ,L,1). Our results indicate that regular removal of sludge from abalone tanks should significantly reduce the dissolved ammonia levels, thereby improving water quality in the culture environment. [source]

Optimization of the simultaneous removal of nitrogen and organic matter from fishery wastewaters

ENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2005
Estrella Aspé
Abstract Anaerobic treatment of saline and protein-rich effluents reduces the organic concentration but forms ammonium that hinders nitrogen removal in a later aerobic treatment. The goal of this work was to optimize the design of a denitrifying,nitrifying system for the simultaneous removal of organic matter and nitrogenous compounds from fishery effluents to meet the Chilean legal standards and to compare pre- and postdenitrification processes in the biological treatment of high-strength effluents to minimize the total volume of biological reactors required. A predenitrifying system, that included three reactors,acidifying anaerobic filter, denitrifying (anoxic) filter, and aerobic-active sludge (nitrifying reactor) with recycle to the denitrifying reactor,reduced nitrogen to 0.33 g of total ammonia nitrogen (TAN) L,1, well above the allowed 0.05 g total nitrogen L,1. The predenitrifying system with a second denitrifying reactor, to which organic matter was added, met the legal organic matter and nitrogen emission concentrations (0.042 g TAN L,1). Conversions were 99.0, 92.5, 90.9, and 99.0% for the anaerobic digestion, first denitrification, nitrification, and second denitrification, respectively. © 2005 American Institute of Chemical Engineers Environ Prog, 2005 [source]

Investigation of the Effects of Salinity and Dietary Protein Level on Growth and Survival of Pacific White Shrimp, Litopenaeus vannamei

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2007
Martin Perez-Velazquez
It is presumed that in hypo- and hypersaline environments, shrimp's requirements for some specific nutrients, such as protein, may differ from those known in the marine habitat; however, few investigations have been conducted in this area of study. In the present investigation, the effects of salinity and dietary protein level on the biological performance, tissue protein, and water content of Pacific white shrimp, Litopenaeus vannamei, were evaluated. In a 3 × 4 factorial experiment, juvenile shrimp with an average initial weight of 0.36 ± 0.02 g were exposed for 32 d to salinities of 2, 35, and 50 ppt and fed experimental diets with crude protein contents of 25, 30, 35, and 40%. A significant effect of salinity on growth of shrimp was detected, with the growth responses (final weight, weight gain) ranked in the order 2 ppt (3.87, 3.50 g) > 35 ppt (3.40, 3.04 g) > 50 ppt (2.84, 2.47 g). No effects of dietary protein level or an interaction between salinity and protein on growth of shrimp were observed under the experimental conditions of this study. Percent survival of shrimp fed the highest protein content (40%, survival of 74%) was, however, significantly lower than those of shrimp fed the other feeds (25, 30 and 35% protein, survival of 99, 91, and 94%, respectively), a result likely associated with the concentration of total ammonia nitrogen, which increased significantly at increasing protein levels. Final water content of whole shrimp was significantly lower in animals exposed to 50 ppt (70.8%) than in shrimp held at 2 (73.7%) and 35 ppt (72.3%). No effect of salinity, protein, or their interaction was observed on the protein content of whole shrimp. The results of the present study are in agreement with reports of superior and inferior growth of L. vannamei reared in hypo- and hypersaline environments, respectively, as compared to what is generally observed in seawater. [source]

Effect of Multiple-batch Channel Catfish, Ictalurus punctatus, Stocking Density and Feeding Rate on Water Quality, Production Characteristics, and Costs

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2006
Brent E. Southworth
To quantitatively define relationships among stocking densities, feeding rates, water quality, and production costs for channel catfish, Ictalurus punctatus, grown in multiple-batch systems, twelve 0.1-ha earthen ponds were stocked at 8,600, 17,300, 26,000, or 34,600 fingerlings/ha along with 2,268 kg/ha of carryover fish. Fish in all ponds were fed daily to apparent satiation using 32% protein floating feed. Temperature and dissolved oxygen in each pond were monitored twice daily; pH weekly; nitrite-N, total ammonia nitrogen, and Secchi disk visibility every 2 wk; nitrate-N, chlorophyll a, total nitrogen, total phosphorus, and chemical oxygen demand monthly; and chloride every other month. The costs of producing channel catfish at different stocking densities were estimated. There were no significant differences (P > 0.05) as a result of stocking density among treatment means of (1) gross or net yields, (2) mean weights at harvest, and (3) growth or survival of fingerlings (24,36%) and carryover fish (77,94%). Mean and maximum daily feeding rates ranged from 40 to 53 kg/ha/d and 123 to 188 kg/ha/d, respectively, and feed conversion ratios averaged 1.75. There were no differences in any feed-related parameter as a result of density. Water quality variables showed few differences among densities at samplings and no differences when averaged across the production season. Yield of fingerlings increased as stocking density increased with significant differences between the two highest and the two lowest stocking densities. Breakeven prices were lower at the higher stocking densities as a result of the higher yield of understocked fish and similar mean individual fish weights produced at these higher stocking densities. Overall, varying stocking densities of fingerlings in multiple-batch systems had little effect on production efficiency and water quality. Additional research on managing the population structure of carryover fish in commercial catfish ponds may be warranted. [source]

Production Characteristics, Water Quality, and Costs of Producing Channel Catfish Ictalurus punctatus at Different Stocking Densities in Single-batch Production

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2006
Brent E. Southworth
Channel catfish Ictalurus punctatus farming is the largest component of aquaculture in the USA. Culture technologies have evolved over time, and little recent work has been conducted on the effects of stocking density on production characteristics and water quality. Twelve 0.1-ha ponds were stocked with 13- to 15-cm fingerlings (16 g) at either 8600, 17,300, 26,000, or 34,600 fish/ha in single-batch culture with three replicates per treatment. Fish were fed daily to apparent satiation with a 32% floating commercial catfish feed. Nitrite-N, nitrate-N, total ammonia nitrogen (TAN), total nitrogen, total phosphorus, chemical oxygen demand (COD), Secchi disk visibility, chlorophyll a, chloride, total alkalinity, total hardness, pH, temperature, and dissolved oxygen (DO) were monitored. Ponds were harvested after a 201-d culture period (March 26, 2003 to October 13, 2003). Net yield increased significantly (P < 0.05) as stocking density increased, reaching an average of 9026 kg/ha at the highest density. Growth and marketable yield (>0.57 kg) decreased with increasing stocking density. Survival was not significantly different among densities. Mean and maximum daily feeding rates increased with density, but feed conversion ratios did not differ significantly among treatments (overall average of 1.42), despite the fact that at the higher stocking densities, the feeding rates sometimes exceeded 112 kg/ha per d (100 lb/ac per d). Morning DO concentrations fell below 3 mg/L only once in a 34,600 fish/ha pond. Concentrations of chlorophyll a, COD, nitrite-N, and TAN increased nominally with increasing feed quantities but did not reach levels considered problematic even at the highest stocking densities. Breakeven prices were lowest for the highest stocking density even after accounting for the additional time and growth required for submarketable fish to reach market size. While total costs were higher for the higher density treatments, the relatively higher yields more than compensated for higher costs. [source]

Ammonia reduction in seawater by Yucca schidigera extract: efficacy analysis and empirical modelling

AQUACULTURE RESEARCH, Issue 8 2010
Roberto A Santacruz-Reyes
Abstract Yucca schidigera is a plant native to southwestern USA and Mexico. Its extract has been used in the livestock industry to control ammonia accumulation in animal holding facilities, and to reduce ammonia concentration in animal excreta. This study investigated the potential and effectiveness of Y. schidigera extract (YUPE) for ammonia reduction in seawater. A dose,response experiment was conducted to determine the effect of different concentrations of YUPE at 0, 18, 36, 72 and 108 mg L,1 on total ammonia nitrogen (TAN) at 1, 3 and 9 mg L,1. At a higher YUPE dosage rate, higher TAN reduction was observed, and TAN reduction was highest during the first 12 h, and decreased thereafter. A stepwise multiple linear regression that included the initial TAN, YUPE concentration and time was developed, which accurately predicted empirical TAN concentrations. Applications of this model for ammonia management strategies were formulated for hypothetical tiger prawn (Penaeus monodon) rearing conditions. YUPE's efficacy for ammonia reduction, natural origin and safety make YUPE a potentially suitable compound for water quality management in mariculture. [source]

Size-related oxygen consumption and ammonia excretion of Eurasian perch (Perca fluviatilis L.) reared in a recirculating system

AQUACULTURE RESEARCH, Issue 1 2009
Vlastimil Stejskal
Abstract Oxygen consumption (OC) and ammonia excretion rates (AE) of perch were measured under commercial-like conditions (temperature 23.3 °C) in both fed (F) and feed-deprived groups (D). Measurements were taken in triplicate in six sized batches of perch ranging from 44.8 to 336.2 g. The mean daily OC was 288.3,180.6 mg O2 kg,1 h,1 for group F fish ranging in size from 44.8 to 279.4 g body weight. The mean daily AE expressed as total ammonia nitrogen (TAN) was 13.8,5.2 mg TAN kg,1 h,1 in the same groups. Daily peaks of OC in group F perch were observed 6 h after the onset of feeding for each size group with relatively stable values up to the end of feeding. Peaks of daily AE in group F perch were observed 10 h after the onset of feeding in each size group, with a rapid decrease up to 16 h after onset. In group D, OC was 181.1,110.5 mg O2 kg,1 h,1 in the weight range 57.9,336.2 g. The daily mean AE was 1.7,0.5 TAN kg,1 h,1 in this group. No dramatic peaks of OC and AE were observed in group D perch. [source]

Settling velocity and total ammonia nitrogen leaching from commercial feed and faecal pellets of gilthead seabream (Sparus aurata L. 1758) and seabass (Dicentrarchus labrax L. 1758)

Toxicity of chlorine to different sizes of black tiger shrimp (Penaeus monodon) in low-salinity shrimp pond water

AQUACULTURE RESEARCH, Issue 14 2002
Husnah
Abstract An experiment was conducted, in a dark room with controlled temperature (27.3,28.4 °C), to determine the acute toxicity of chlorine concentration to black tiger shrimp (Penaeus monodon fabicus) of sizes 0.02 g, 2.75 g, 8.47 g and 23.65 g. Toxicity tests on each of these shrimp sizes were run in triplicate in glass jars under static conditions without media renewal. The concentration of active chlorine that killed 50% of the shrimp of each size after 24-h exposure (LC50 -24 h) was used as an indicator of acute toxicity. Chlorine concentrations applied in the shrimp toxicity test ranged from 2.0 to 14.5 mg L,1 in shrimp pond water. As the test water contained total suspended solids of 22.0,85.0 mg L,1 and total ammonia nitrogen of 0.18,0.40 mg L,1, the resultant concentrations of combined residual chlorine ranged from 0.6 to 3.5 mg L,1, which were the effective doses causing shrimp mortality. The test results showed that 24-h LC50 for average shrimp size at 0.02, 2.75, 8.47 and 23.65 g occurred in water containing combined residual chlorine at a concentration of 0.91, 1.39, 1.74 and 1.98 mg L,1, for which the original application doses were 6.96, 2.05 11.50 and 13.34 mg L,1 respectively. [source]