filtration

About 7 to 8% of the body weight of tuna fish is the digestive tract and it is an economic source for lipase enzyme extraction. Enzyme extraction was done using Tris hydrochloride buffer (25 mM with pH; 7.8). Then the crude extract was precipitated and dialyzed in the range of saturation between 30, 45 and 60% ammonium sulfate. For further purification, ion exchange chromatography using a DEAE-CMC column with dimensions (2.5 × 30 cm) and gel filtration chromatography using a Sephadex G-100 column (1.8 × 80 cm) were used. Purified lipase enzymes obtained by precipitation with ammonium sulfate 30, 45 and 60%, respectively, have molecular weight (68.3, 38.41, and ND KDa), pH (7.1, 6.9, and 7.4), The optimal temperature (55, 42 and 38 °C) and specific enzyme activity (3.42, 2.8 and 1.4 U/mg) were using paranitrophenyl palmitate (pNPP) as a substrate. The results indicate the possibility of extracting and purifying lipase enzyme from the digestive system of aquatic animals with suitable biochemical characteristics for use in chemical and food industries.

The aim of this study was to investigate the effect of using basalt in reducing the nitrogen content of water and the growth performance of goldfish (Carassius auratus) for 60 days.

For this purpose, 245 pieces of goldfish with a mean weight of 9.42 ± 0.15 g and a longitudinal mean of 3 ±0.02 cm were purchased and after adaptation for one week in distribution experimental treatments. Were. Experimental treatments included control treatment (without filter), zeolite with 10 g/l, basalt with different amounts of 10, 20 and 30 g/l and for each level of filter, fish density during the experiment, two densities of 1.5 And 3 cm per liter were considered, which were randomly distributed to 25 pieces of fish for a density of 1.5 and 50 pieces for a density of 3 in 50 liter aquariums.

The results of this study showed that the presence of filtration had a positive effect on fish growth rate and fish had better growth factors in treatments of both densities that had filters compared to the control group (p<0.05). Ammonia, nitrite and nitrate levels in the eighth week of the study in treatments containing filters of both densities were significantly lower than the control treatment and did not exceed the toxic range (p<0.05).

According to the studies, it was found that basalt volcanic rock has a very high ability to absorb nitrogen compounds in water and 10 g/l basalt can be treated as a substitute for 10 g/l zeolite with a long reduction time more suggested.

Nanotechnology is an emerging technology in many industries, including aquaculture sector. Although these nanoparticles are widely used in the aquaculture, the increase in their production and use has raised many concerns about their potential toxicity to human health and the environment. Therefore, the present study aims to review the benefits and disadvantages of nanotechnology in aquaculture. This work will provide a comprehensive review to better undestanding of decision-makers in aquaculture section. In this study, the role of nanotechnology and its benefits in various sectors of the aquaculture industry, such as nutrition, reproduction, water purification, fishing and health control of diseases are discussed, and then, the negative effects and toxicity. The use of these materials in rearing systems was evaluated from an ecological and environmental point of view.

At present, the ornamental fish aquaculture and edible fish aquaculture are growing, and this requires the high consumption of water in culture systems aimed at breeding and cultivation of this group of aquatic animals. Considering, the limitations of water resources, sustainable development of ornamental fish aquaculture requires saving and minimizing water consumption. One of the effective strategies to reduce water consumption and reuse, is water treatment. Nanotechnology has grown over the past years in all aspects of science and industry. Due to the efficiency of nanotechnology and the diversity of its methods of use, it can be widely used in treatment of water in culture systems. In this paper, various methods of using nanotechnology in wastewater treatment, with emphasis on carbon nanotubes, have been investigated.

Pretty-blocked Venus ( Circenita

callipyga ) belong to Veneridae family is native species in the Persian Gulf and Oman Sea. This study was conducted from January to May 2014 in Molluscs Research Station in Bandar Lengeh. Filtration rate of ( Isochrysis aff galbana )with Pretty-blocked Venus was studied in 6 temperature include 15, 20, 24, 28, 32, 36 0C and 6 salinity treatment include 20, 25, 30, 35, 40, 45 ppt . For each treatment 3 replications were consider ed and each replication include 10 venus with 24±2 mm DVM maintained in 15 liter seawater. 24 hours before starting, venus clam were not fed and for estimating increase or decrease in microalgae for each treatment a replication without venus clam was considered. Results show that maximum and minimum filtration relate to 28 0C with 3588695±300141 and 20 0C 1451848±300141 µl/hour/shell, respectively. Comparison of filtration rate shows that there was no signification difference between 28 with 32 and 20 with 15 0C treatment (P>0.05). In treatment 20 and 25 ppt no filtration was observed and venus clam did not open its shells during study. But maximum filtration was obtained in 40 ppt treatment which 2374067±997049 µl/hour/shell. No significant difference was observed between 35 and 40 ppt (P>0.05) but these treatments have significant difference with 30 and 45 ppt salinity (P<0.05). Result Show that optimum temperature and salinity for filtration in Pretty-blocked Venus ( C.callipyga ) were 28 0C and 40 ppt respectively