Showing 7 results for Effluent
Volume 3, Issue 4 (2-2015)
Abstract
Based on the macro-invertebrate community and physico-chemical indices, water quality of the Tajan River in 6 stations along 80 km of the river length was assessed. Monthly sampling was conducted for one year (September 2011 to August 2012), using a surber with 30.5 × 30.5 cm dimensions and a 60μ mesh net for the benthic invertebrates sampling. The identified macro-invertebrates belonged to 31 families, 12 orders and 5 classes, the highest and the lowest abundance of which belonged to Psychodidae and Chironomidae, respectively. Based on Hilsenhoff Family Biotic Index, the research stations were classified into 4 qualitative categories, viz. excellent, good, fair, and fairly poor. Stations 1 and 5, respectively, showed the highest and lowest HFBI index. The highest and the lowest values for the Shannon–Weiner index were recorded in station 1 and station 2, respectively. The results of physicochemical parameters indicated reduced dissolved oxygen in the stations 2 and 5, and increased TDS in station 2 and 1 and increased nitrite and ammonium in station 3. Results of Spearman correlation coefficients between biotic indices and physicochemical variables revealed significant relationship between DO, TDS, EC, PO4 and water flow with HFBI and Shannon-Weiner indices. This study showed, generally pollution in stations 2 and 5 has reduced water quality in these station's.
Volume 12, Issue 1 (12-2020)
Abstract
Background and Objective: Polyhydroxyalkanoates (PHAs) are polymers with biodegradable and biocompatible properties that are produced by some bacteria. In the present study, petroleum sediments were applied to screen PHA-producing bacteria.
Method: The industrial culture medium of petroleum effluent was used as a low-cost and economical medium for isolating and identifying the superior PHA-producing strain. Finally, the chemical and physical properties of the extracted biopolymer were investigated by Fourier-transform infrared spectroscopy, differential scanning calorimetry, and proton nuclear magnetic resonance.
Results: In general, 11 out of 76 isolated bacterial strains could produce biopolymers among which, the Sb8 strain was selected as the best PHA-producing strain in the industrial medium with the cell dry weight of 44.13% and 1.2 g/l in 27 h. This strain was identified as Citreicella thiooxidans by sequencing determination. Eventually, the results of physicochemical analyses revealed that polyhydroxybutyrate (PHB) was the extracted biopolymer.
Conclusion: The present study is the first report on PHB production by Iranian native Citreicella thiooxidans strain by focusing on identifying and separating producing bacteria, as well as determining the type of the produced biopolymer and the production capability in a low-cost culture medium of the petroleum effluent. Considering the production of the biopolymer with a relatively high yield percentage without adding any supplement to the petroleum effluent medium, the isolated wild strain has the potential to produce PHB.
Volume 13, Issue 2 (6-2024)
Abstract
Wastewater treatment with microalgae and its reuse is an effective step toward reducing water consumption and preserving water resources. The possibility of growing spirulina microalga on cattle effluents and the possibility of purifying effluents using microalga were investigated. Different concentrations of standard culture medium (Zaruk)-wastewater were used to measure the optimal algal growth on wastewater and to determine the concentration of effluent-Zaruk for optimal algal growth. The treatments were T1 including 100% Zaruk and no wastewater, T2 including 75% Zaruk and 25% wastewater, T3 including 50% Zaruk and 50% wastewater, T4 including 25% Zaruk and 75% effluent and T5 including 100% effluent without Zaruk. Treatments that had more Zaruk, showed more optimal growth, and those that had a higher concentration of effluent often showed a relatively lower growth of algae biomass. The results showed the high growth of algae on the concentrated effluent. T1 with 0.35 and T2 with 0.3 g/liter of dry biomass had the highest biomass of microalgae. T1, T2, T4, T3, and T5 had the highest to the lowest amount of phycocyanin pigment production in microalgae, respectively. The highest removal of nitrate belonged to T5 and T4 with 82.57% and 78.21% removal respectively, and the lowest nitrate removal belonged to T1 and T2 with 57.17% and 70.94%, respectively. The highest removal of phosphate belonged to T1 and T2 with 94% and 92.11% removal, respectively. The lowest removal of phosphate belonged to T4 with 84% removal. Findings indicated the high potential of microalga for treating cattle wastewater.
M. Alikhasi, M. Kouchakzadeh, E. Baniani,
Volume 14, Issue 6 (11-2012)
Abstract
Shortage of irrigation water is a crucial problem especially in arid and semiarid regions; therefore, application of wastewater in agriculture in such regions seems to be an indispensable solution. A field experiment was conducted in non-agricultural soil to investigate the effect of Treated Municipal Wastewater (TMW) on the yield and fiber quality of cotton (Gossypium hirsutum L.) crop. The treatments consisted of surface irrigation by different mixtures and as well, through different intervals of freshwater plus TMW. Two additional treatments, namely, irrigation with freshwater and with TMW were considered as control. The experimental design was a randomized complete block one with eight treatments and three replications. The results indicated that cotton yield, number of bolls per m2, Leaf Area Index (LAI) and plant height were significantly higher when the crop irrigated with TMW rather than with freshwater. The crop yields in TMW vs. freshwater treatments were about 2,200 and 780 kg lint ha-1, respectively. There were no significant differences observed between interval and mixture treatments when the same percentages of freshwater and TMW applied. Also there was no significant detrimental effect observed on the characteristics of cotton fiber quality when the crop irrigated with TMW.
Volume 16, Issue 2 (6-2016)
Abstract
The treatment of wastewater generated from acrylonitrile butadiene styrene (ABS) resin manufacturing industry have a great importance due to its high chemical oxygen demand (COD) and some other toxic substances. Activated carbon adsorption, chemical oxidation and biodegradation are the most conventional methods to the treatment of ABS effluents. Among them, the biological treatment as an environmentally friendly technology is highly regarded in the bio treatment and biotransformation of the toxic compounds of ABS wastewater to the intermediate and final compounds such as CO2 and water. This study was conducted to evaluate the performance of an activated sludge system for pretreating ABS manufacturing effluents. The wastewater pretreatment plant is consisted of 3 fine screens, a grit chamber, an equalization basin, dissolved air floatation (DAF) system, an activated sludge reactor and a final clarifier. This system was operated to reduce the TSS and COD values in the effluent in order to obtain to interior discharge permits to the central wastewater treatment utility operated by Tabriz petrochemical complex. Four runs weighed average sampling was conducted during 6 months according to the standard methods of the examination of water and wastewater. The parameters including COD, BOD5, TSS, TDS, sulfate, total kjeldahl nitrogen (TKN), ammonia-N, nitrate-N, alkalinity, cyanide, phosphate and pH were measured in wastewater samples according to the standard methods. The concentrations of acrylonitrile, acrylamide and acrylic acid in wastewater samples were determined using gas chromatography (GC) equipped with flame ionization detector (FID) with capillary column. Microbial structure of activated sludge was also evaluated using R2A, PCA and Nutrient Agar culture media as well the biochemical standard tests. According to the results, at surface loading rate of 2.76 m3/m2.h applied to DAF, the COD and TSS removal efficiencies of 24 and 43% were obtained, respectively. The ratio of BOD5/COD in the influent was 0.57 indicated the moderate biodegradability of ABS wastewater. In addition, the COD and BOD5 removal efficiencies in biological reactor were 59 and 68% respectively, at the organic loading rates (OLR) of 0.79 ± 0.06 kgCOD/m3.d. Totally, the COD, BOD5 and TSS removal efficiencies in the pretreatment system were 80, 90 and 88%, respectively. In addition, at the acrylonitrile loading rates of 0.067 ± 0.008 kg ACN/ m3.d, the removal efficiency of acrylonitrile was 91% which 26% of that has occurred in the biological reactor. Also, the removal efficiency of cyanide was 97% which only 4% of that has occurred in the biological reactor. Twenty bacterial strains were isolated and identified from the activated sludge samples. Among the isolated bacterial strains, four strains include Alcaligenes sp. Pseudomonas sp. Bacillus sp. and Moraxella sp. were identified as heterotrophic nitrifiers. Based on the results, the nitrifier bacteria have played an important role in the degradation of acrylonitrile in the biological activated sludge system. The results of parameters analysis, performance evaluation and microbial assessment revealed the satisfactory performance of COD removal as well nitrification. However, it seems that a significant portion of the volatile organic compounds (VOCs) are removed from the influent wastewater by stripping.
Volume 16, Issue 90 (8-2019)
Abstract
The purpose of this study was to investigate the factors affecting the fermentation process in the production of bacteriosin by two commercial probiotic bacteria in dairy factories effluents as a culture medium. Therefore, the effect of independent variables, including incubation temperature (30, 34 and 38 °C), initial pH (5, 6 and 7), duration of incubation (12, 30 and 48 hours), yeast extract concentration (0, 2 and 4 %), probiotic bacterial species (L. acidophilus LA5 and B. animalis subsp. lactis BB12) and culture medium (cheese whey and milk permeate) was studied using a completely randomized design with two-level factorial arrangement. The results showed that the temperature and time of incubation as well as the culture medium had a significant effect on bacteriosin production (p<0.05). Also, temperature, yeast extract concentration, culture medium type and culture of bacteria had a significant effect on biomass (p<0.05). Initial pH and culture medium had a significant effect on total protein content (p<0.05). Based on the results of incubation temperature, duration of incubation, yeast extract concentration, type of culture medium and type of probiotic bacteria had a significant effect on the titratable acidity (p<0.05). The levels of bacteriosin activity, biomass, total protein, and titratable acidity were in the range of 1000 to 5000 AU/mL, 0.80 to 8.67 g/L, 107.75 to 351.92 mg/L and 0.25 to 1.41 g/L, respectively. In general, the results showed that cheese whey and L. acidophilus LA5 is the suitable culture medium and bacterium for producing bacteriosin, respectively.
Volume 24, Issue 1 (4-2024)
Abstract
The quality of water available to humans has been seriously threatened due to population growth and the resulting increase in urban and industrial wastewater. To evaluate changes in the water quality of the Karun River in the urban area of Ahvaz, a simulation model was developed and used to assess the river's water quality based on existing standards. Results show that the quality variables of the river are highly dependent on the season of the year, with the largest changes in dissolved oxygen occurring during the driest and wettest seasons. Comparison of the river's current situation with national and international standards indicates that the water quality does not meet most standards, except during the autumn season when the flow rate is highest. Even if all effluents entering the river comply with existing discharge standards, the quality of the river does not meet desired standards. This highlights the importance of considering specific hydraulic conditions and the effect of time on river quality when updating existing standards.
