7 research outputs found

    Leaching characteristics of the fine fraction from an excavated landfill: physico-chemical characterization

    Get PDF
    Leaching of fine fraction (<10 mm) obtained from landfill mining activities in an Estonian landfill was done. On-site excavation was carried out in four test pits (TP1, TP2, TP3, TP4) that were further divided in four layers (L1, L2, L3, L4). Total chemical oxygen demand (CODt), dissolved chemical oxygen demand (CODd), total organic carbon (TOC), dissolved organic carbon (DOC) and metals (Zn, Cu, Pb and Cd) were analyzed. The results showed that approximately 70 % of CODt were in particulate/colloidal state. The TOC released ranged between 2326 and 3530-mg/kg dry matter for test pits suggesting spatial differences in the studied landfill. DOC ranged between 365–874 and 317–940 mg/kg for different test pits and sampling layers, respectively. Low average leaching rates of metals were observed (0.2–1.5 %). Pb had a significantly higher average leaching rate (1.0 %) compared to Zn (0.70 %) and Cu (0.35 %). The potential use of CODt as a surrogate indicator of TOC, DOC and Zn on the basis of high correlation coefficients was observed. To conclude, the implementation of adequate strategies to manage fine-grained fractions obtained from excavated waste relies on physico-chemical characterization of both the fine fractions itself and the leachate generated during storage and use. © 2015 Springer Japa

    Possibility of using fresh water rotifer Brachionus calyciflorus for feeding Persian sturgeon Acipenser persicus

    Get PDF
    Acipenser persicus, one of the native Species living in the southern part of the Caspian Sea, has high Percentage of larval mortality. Therefor to decrease the rate of mortality of larvae survival and to increase to regenerate properly during the active feeding process of fish larvae, while under artificial reproduction they were fed withe fresh water rotifer. Four types of feeding treatments were applied as follow: Treatment 1: Similar to normal process, first withe Artemia cyst then withe Daphnia Treatment 2: Mixture of Artemia, Rotifer and Daphnia; Treatment 3 freshwater Rotifera ;Treatment 4: fresh water Rotifer enriched with Vitamin C (Ascorbic acid- 6- Palmytat).Three replicates were used for each treatment. In the process of each observation 45 larvae in containers withe 100 liter capacity filled with 30 liters of water, after 8 days of external feeding process, were inspected closely, during which , they were under biometric measurement once every two days. Larvae were fed Four times a day at a rate of 25% of their body weight. The average temperature estimation was 22.5±0.5 centigrade, pH .of water being 85±0.1 while Oxygen proved to be 9.58±0.2 mg/l. At the end of the observation, the profile fatty acids of the remains were studied. The growth factors, the mouth size of the larvae and the expansion of the mouth size compared to the total length of the larvae during the whole observation were inspected. Credibility of data designated was examined by Shapiro Wilks test. Specific growth rate (SGR), weight growth (WG) and feed conversion ratio (FCR) were contemplated by one-way analysis test, and significant difference Tukey's test. The most notable diversity was evident between treatment 2, whose indicative factors were in the following order: 4.65± 0.06, 45.18±0.66, 4/48 ± 0/07 and treatment 4 whose indicative factors showed the following results: 10.47±0.04, 124.42±0.62, 1.51±0/008.For the determination of fatness rate and weight gains, Kruskal Valis and Man vit ni test were used .In this part of study , the highest diversity fatness appeared to be between treatment 4 ,reflecting 0.79±0.07 and treatment 2 showing the result 0.62±0.05.The highest gain was related to treatment 4, whit the rate of 99.33±0/68 mgr and the lowest gain occurred in treatment 2 white the rate 62.36 ± 0.65 mgr. This study also revealed that, the survival ratio connected with treatments 3 and 4, compared treatments 1 and 2, were significantly different. The profile of fatty acids also showed much higher percentage of PUFA and HUFA in treatments 3 and 4, than those in other treatments. Furthermore Brachionus calyciflorus proved to be a proper food supply for larvae. Therefore by building suitable pools next to the work side, other kinds of species fresh water rotifer could also be used as food improvements for feeding larvae

    Biomass estimation of demersal resources in the Persian Gulf and Oman Sea by swept area method

    Get PDF
    Regarding to monitor of demersal resources in the Persian Gulf and Oman Sea, and also biomass and CPUA estimation of them, ten research cruises were carried out by using R/V Ferdows-1 equipped with bottom trawl, covering the area from 49Âș 00ÂŽ E in the west (north-west Persian Gulf) to 61Âș 25ÂŽ E in the east (borderline with Pakistan) from 2012 to 2014 The study area was stratified into 17 strata (A to Q) of which 10 strata (A to J) were in the Persian Gulf and 7 strata (K to Q) were in the Oman Sea, covering the depths of 10-50 m in the Persian Gulf and 10-100 m in the Oman Sea. A total of 316 stations were randomly selected and the biomass and CPUA were estimated by swept area method during this three years period, the strat A and B weren’t covered. The comparison between two regions indicated that the percentage of density of demersal fishes in the Persian Gulf during years 2012, 2013 and 2014 were 1.0, 1.4 and 1.6 times more than the Oman Sea and totally 50-60% of total biomass was found for the Persian Gulf. Also a comparison among 17 strata the highest biomass was found for K region (Sirik to Jask) in the Oman Sea in 2012 & 2014; and C region (Genaveh to Bordkhoon) in 2013 in the Persian Gulf. The same comparison was done for CPUA of commercial, non-commercial and total in both water bodies and it was found that in years 2012 to 2014 the region K (Sirik to Jask) in the Oman Sea and Stratum Q (Bersi to Gwatr) had the highest value of CPUA. On the contrary, the stratum M (Biahi to Galak estuary) showed the lowest value of biomass for both commercial and non-commercial fishes. With review the mean CPUA in different depth layers for years 2012, 2013 and 2014, it was concluded that in the Oman Sea with increasing the depth, the mean CPUA is decreased and the lowest CPUA belongs to depths of 30-50 m The comparison between commercial and non-commercial groups in both ecosystems, it concluded that the density of commercial species were higher than non-commercial ones; and for years 2009, 2010 and 2011 the commercial species consist of 63.4, 65.0 and 59.7 % of total biomass. In all years the Persian Gulf indicated higher values than the Oman Sea. The most abundant fishes were Rays, Ribbon fishes, Carangids, Grunts, Japanese threadfin bream, Lizardfish and Barracuda for both Persian Gulf and Oman Sea
    corecore