30 research outputs found

    Accumulation of heavy metals in agricultural soil irrigated by sewage sludge and industrial effluent (case study: Agh ghallah industrial estate)

    Get PDF
    Background and purpose: Industrial effluent and sewage sludge are used as fertilizer since they contain high levels of nutrient. The main pollutant in industrial effluent is heavy metals. In this study an assessment was made on the impact of industrial wastewater effluent and sewage sludge on accumulation of heavy metals in agricultural soil at Agh ghallah industrial Estate. Materials and methods: In a descriptive-analytic study, 72 samples (sewage sludge, effluent and soil) were collected from the Industrial state. All sampling and tests were performed according to standard methods and concentration of heavy metals was determined using polarography method. To analyze the data, SPSS was used and 95 confidence intervals (P 0.05). Conclusion: The concentrations of heavy metal were found lower than the maximum allowable level. Therefore, in this area, wastewater and sewage sludge could be used to irrigate agricultural lands and greenspaces in shortage of water, however, environmental regulations should be taken into account. © 2015 Mazandaran University of Medical Sciences. All rights reserved

    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

    Effectiveness of chitosan as natural coagulant aid in removal of turbidity and bacteria from turbid waters

    No full text
    There has been considerable interest in the development of natural coagulants such as chitosan. By using natural coagulants, considerable savings in chemicals and sludge handling cost may be achieved. Chitosan, a natural linear biopolyaminosaccharide, is obtained by alkaline deacetylation of chitin. Present study is aimed to examine the effects of aluminium sulfate (alum) as coagulant in conjunction with chitosan as coagulant aid on removal of turbidity and bacteria from turbid waters. These tests were carried out using artificial water and kaoline as model suspensions to represent the wide range of natural turbid waters. A conventional jar test apparatus was employed for the tests. After determining of optimum mixing intensity and duration, alum suspensions were added to the samples and after one minute, the desired doses of natural chitosan were added. In optimum condition, residual Al+3 in treated water was less than 0.2 mg/l and meets the EPA guidelines. Turbidity removal efficiency was 74.3- 98.2% by chitosan at a pH 7.0-7.5 for all turbidities. In addition, chitosan significantly reduced the required dosage of primary coagulant 50-87.5%. Bacteria reduction of 2-4 log units (99 - 99.99%) was obtained within the first 1 to 2 h of treatment. Overall results indicate that E.coli was removed better than S. faecalis. The main effects of coagulation by chitosan on bacteria are enmeshment and stack on the microbial cell surface. We demonstrated that optimal design method is an efficient approach for optimization of coagulation-flocculation process and appropriate for raw water treatment

    Monitoring of tuna resources (yellowfin and skipjsck tunas) in Oman Sea along Sistan & Balouchestan coastal waters

    Get PDF
    Collecting of biometric parameters and catch and effort data were made for yellowfin and skipjack tunas from artisanal gillnet and industrial purse seine fisheries during the years 2002-2004 in Oman Sea along Sistan and Balouchestan coastal waters. The previous available data was used for the purpose of better monitoring the resources. The frequency of maturity stages and GSI values obtained from yellowfin showed a spawning period from February to May, peaking in April-May. For skipjack, the data indicated a long spawning period which beganed in December with peaking in April-May. LM50% was obtained as 83.1 and 62.4 for yellowfin and skipjack tunas respectively. Sex ratio by size group showed a predominance of males with larger fish. Analysis of stomach contents showed a significant proportion for the both species. The composion of food contents by occurrence method revealed that fish were the most dominant food items by year for the specise. Presence of squilla, crabs, shrimps (Larval stage), belonging to Peneaidea family, in large quantities were the oblivious food items so that they had not been reported by previous studies. Blooming of squilla, Natosquilla investigators, in the western Indian Ocean provided a situation to be observed in large occurrence in yellowfin and skipjack stomach contents. The ratio was more in yellowfin stomachs when compared to skipjack ones which accounted for 38%, 19% and 35% of the total stomachs studied by the study year. The shrimps prey were only observed in skipjack gut contents (with exception of one case in yellowfin stomach) which were the second major component in 2002 and 2003(24% and 17% respectively). Comparsion of mean length showed a sharp decrease from 1992 to 2004 for the species. Regarding yellowfin the mean length from 93.2 cm FL in 1992 reached to 83.2 cm FL in 2004 and from 64.95 to 58.51 cm FL for skipjack. In spite of decreasing mean length for yellowfin, the value increased in 2004 in comparison to 2003 which was in agreement with Indian Ocean data. Comparative analysis of length frequency with LM50% indicated that immature fish were the major part of the catch. There are available information on population dynamic parameters. A comparative analysis of CPUE,s (kg/panel.day) from artisanal gillnet fishery for yellowfin and skipjack tunas revealed a decreased value by fishing craft class in 2005 when compared to 1998 data, but increased in 2003. Increased trend of the species catches by fishing craft class was due to increased fishing effort. Analysis of the statistical catch and effort data for the study years, irrespective of fishing craft class, showed that total landings of the species have increased 4.4 fold in spite of attaining CPUE to 7% in decrease which was a consequence of increased fishing effort up to 4.7 fold. The CPUE, s (tons / positive set) from industrial purse seine fishery increased in 2003 and 2004(39% and 10% respectively), but declined up to 54% in 2005. The trend is in agreement with purse seine fishery data from Indian Ocean where the increased values were attributed by larger size of yellowfin. The purse-seine fishing ground data revealed that the major sets were made in Persian Gulf, whereas a shift towards Oman Sea in eastern part of Sistan and Balouchestan coastal waters is recommended to be a suitable fishing area for the first half of year and towards offshore waters in Indian Ocean for the second half of year. For attaining a sustainable fishery system, it is recommended to regulate the gillnet mesh size and introduce longline fishery in the area along with stopping any further increased fishing effort in artisanal gillnet fishery

    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 49º 00´ E in the west (north-west Persian Gulf) to 61º 25´ 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

    Groundwater quality assessment of north of Iran (Golestan Province) using multivariate factor analysis and GIS techniques

    No full text
    Groundwater is one of the most important sources of drinking water. Since the quality of water directly influences consumers� health, it is essential to assess the quality of water and related factors. This descriptive-analytical study was performed on physical and chemical variables of water samples collected in the dry and wet seasons during 2006�2020 period. Changes in groundwater quality were investigated by factor analysis (FA) model and geographic information system (GIS) software. Based on factor analysis model, EC, TDS, TH and Mgþ2 levels were the most important factors affecting the quality of water. Due to the high level of hardness (dry seasons; 389.4 mg/l and wet seasons; 418.4 mg/l) and sodium in water (dry seasons; 138 mg/l and wet seasons; 158 mg/l), necessary measures should be taken before drinking and agriculture uses. Changes in the water quality were more related to natural factors and human activities. The invasion of saline water into the groundwater aquifers in the study area should be considered. © 2022 The Authors

    An Interactive Fuzzy Satisfying Method Based on Particle Swarm Optimization for Multi-Objective Function in Reactive Power Market

    No full text
    Reactive power plays an important role in supporting real power transmission, maintaining system voltages within proper limits and overall system reliability. In this paper, the production cost of reactive power, cost of the system transmission loss, investment cost of capacitor banks and absolute value of total voltage deviation (TVD) are included into the objective function of the power flow problem. Then, by using particle swarm optimization algorithm (PSO), the problem is solved. The proposed PSO algorithm is implemented on standard IEEE 14-bus and IEEE 57-bus test systems and with using fuzzy satisfying method the optimal solutions are determined. The fuzzy goals are quantified by defining their corresponding membership functions and the decision maker is then asked to specify the desirable membership values. The obtained results show that solving this problem by using the proposed method gives much better results than all the other algorithms
    corecore