جستجوی مقالات مرتبط با کلیدواژه "effluent" در نشریات گروه "شیلات"

In this study, the effect of the effluent from rainbow trout ponds was investigated on the yield, concentration and uptake of nitrogen, phosphorus and micronutrients on the silage corn in the Golpayegan research station for Husbandry and Agriculture in Isfahan. 45000 fish with an average weight of 10 ± 2 g were uniformly divided in 9 ponds (20 × 2.2 × 1.3 m) for six months. The research was conducted in a complete randomized block design with five treatments in triplicate. The treatments were included 1) irrigation with well water without any fertilizer as the control, 2) irrigation with well water and use of urea, triple superphosphate and potassium sulfate as the fertilizers, 3) irrigation with fish ponds effluents without any fertilizer, 4) irrigation with fish ponds effluents and use of the fertilizer, and 5) irrigation with fish ponds effluents with 50 percent of the fertilizer. Results showed that the use of fish ponds effluents significantly caused increasing in corn yield and concentration of zinc, cupper, nitrogen, phosphorus, manganese and iron (p<0.05). In addition, using fish ponds effluents with the 50% of chemical fertilizer led to increase corn yield by 44 percent compared to the control group (p<0.05). Moreover, the uptake of iron, zinc, copper and manganese by corn were increased significantly compared to the control group through use of fish ponds effluents water with fertilizer (p<0.05). The highest and lowest yield of corn was obtained in the irrigation with the effluent of fish ponds effluents coupled with chemical fertilizers and the control group, equal to 73.7 and 44.4 tons per hectare, respectively, which had significant difference with each other (p<0.05). Therefore, the use of fish farm effluents for production of corn not only increased the yield but also dramatically enhanced fertilizer utilization.

The aim of this study was investigating the antimicrobial activity of microalgae Sandosmus and Spirulina cultivated in the BG-11 culture medium and the effluent of the desalination facility of Bandar Turkmen unit, Golestan province, in inhibiting the growth of Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Algae were extracted by water-alcohol method in proportion (500cc of alcohol and 50cc of distilled water) and determination of minimum inhibitory concentration (MIC) was checked by broth micro dilution method (96 house plates), and were compared to their usual environment with the amount of antibacterial activity grown in water. The results of two mentioned bacteria in the presence of different concentrations of aqueous-ethanolic extract within 24 hours showed that in the extract of the genus Sandosmus and Spirulina grown in BG-11 culture medium and 50 and 100% effluent dilutions, there was no antibacterial effect against Escherichia coli and Staphylococcus aureus bacteria during (24 hours). Sandosmus extract grown in BG-11 with 25 and 50 concentrations had higher E. coli bacteria volume than spirulina in the early hours. As the concentration increases, the volume of bacteria decreases in the early hours. Spirulina extract grown in BG-11 showed high resistance to Staphylococcus bacteria in the early hours compared to Sendesmus. Sendesmus extract grown in 50% wastewater compared to Spirulina had the highest amount of E. coli bacteria in the final hours, so it showed a high resistance to E. coli compared to spirulina. Also, in the extract of Sandosmus grown in 50% wastewater at concentrations of 25, 100 and 200 mg/ml in the final hours, the volume of Staphylococcus bacteria was higher than the concentration of 50 mg/ml, and in spirulina there was a constant trend in the final hours. In both extracts grown in 100% wastewater against E. coli bacteria in all concentrations within 4 hours, they showed the highest amount of bacteria. Therefore, in all concentrations of both extracts, they showed an increase in the volume of Staphylococcus bacteria over time (2-4 hours). Therefore, spirulina grown in 100% wastewater had a stable trend in the last hours compared to Sandosmus and showed more resistance to staphylococcus.

One of the main requirements in wastewater treatment is the need to remove nutrients, especially nitrogen and phosphorus, which can lead to eutrophication of these sources if they are discharged to water sources. In this study, the application of dairy effluent in the cultivation of Spirulina platensis was studied with the aim of treatment and removing nutrients and also the amount of biomass produced. Thus, two concentrations of Spirulina platensis (0.05 and 0.1 g/l) were cultured in three dilutions (25, 50, 75%) of dairy effluent. The results showed that both factors of different concentrations of microalgae and different dilution of effluent had an important role in nutrient absorption and biomass production. The highest percentages of nitrate, phosphate, ammonia removal (98.03, 74.14, 97.44%) as well as maximum biomass (920 ± 0.09 g/l) were related to 25% dilution of the effluent and secondary microalgae concentration. In fact, the secondary concentration of microalgae (0.1 g/l) performed better than the primary concentration (0.05 g/l) and succeeded in removing higher amounts of nutrients. Thus, dairy effluent is a suitable culture medium for the growth of Spirulina platensis and by reducing the dilution percentage from 75% to 25% and increasing the amount of available nutrients, the amount of biomass increases.

Water pollution is a major global problem that affects plants and living organisms. Factors affecting water pollution include industrial, agricultural, and human pollutants. Qarasu river is very important in terms of pollution due to the use of river water in the agriculture and aquaculture sectors. In this research, the effect of intensive fish farms and the riverbed material was investigated on the abundance of macrobenthic communities. For this purpose, four stations 1) the station upstream and before the fish farms (as control station), 2) the station between the fish farms, 3) the last station of the farms, and 4) the downstream station at a distance of 4 km from the last farm were selected. A sampling of the macrobenthos and riverbeds was done in two seasons, winter and spring, and their frequency was calculated in the sampling stations and months. The highest abundance was related to the family’s Chironomidae (1456 numbers per m2) and Simolidae (2737 numbers per m2) from the Diptera order, which were observed in the effluent of station 2 and station 4 in the winter season, respectively. In addition, the type of the river bed was determined to find the correlation with macrobenthic species. The identified macrobenthos was classified into trophic groups and the relationship with the type of substrate was determined using the Pearson correlation. The correlation of different macrobenthic species with sampling stations and months was found using Canoco software and CCA statistical analysis. The present study showed that the effluent from intensive fish farms had an effect on the abundance of macrobenthos in the Qarasu River, which could be due to the increase in nutrients in the river water from the release of the effluent, and decrease in temperature and decrease in the decomposition of nutrients in the winter season. Therefore, based on the findings, the presence of different functional macrobenthic groups is affected by the type of riverbed and different seasons of the year.