The purpose of our study was to identify the native bacteria with the ability to degrade azo dyes from the rhizosphere of Sparganium erectum L., and Typha latifolia L. plants that were grown on a drain of a textile mill. Eight and one strain with decolorization ability of Cibacron Brilliant Red EB and Terasil Red 3BL-01 were isolated from the saline rhizosphere of Sparganium erectum L. and latifolia L. plant respectively. Results showed that the bacteria isolated from the rhizosphere of Sparganium erectum L. are more capable of decolorizing azo dyes. Based on the 16S rRNA sequencing, selected strains were identified as follows: Enterobacter ludwigii strain SNP3 (OL719291), Rhodococcus fascians strain SNP5 (OL759129), Pseudomonas aeruginosa strain SNP10 (OL759126), and Bacillus safensis strain SNP13 (OL759127). The results of azo dyes biodegradation tests revealed that strains SNP10, SNP3, and SNP5 were more capable of decolorizing 94-97%, 72.53-73.8, 72.53%, and 71.13-73.5% of Cibacron Brilliant Red EB at concentration 10-20 mg/L within 72 h, respectively. Besides, strain SNP13 was the fastest strain in decolorization of Cibacron Brilliant Red EB with 68% and 59% decolorization activity at 10 and 20 mg/L respectively (24 h). Only strains SNP3 and SNP13 could decolorize 83% and 77% of Terasil Red 3BL-01 (30 mg/L), respectively. For the first time, our research findings illustrated that indigenous rhizospheric bacterial strains isolated from Sparganium erectum L. plants have the potential to apply as an azo dye breakdown tool in textile effluent treatment or other ecosystems.

Lighvan hot spring and Toptapan mineral spring are located in the Eastern Azarbaijan, NW of Iran. The host rocks of Lighvan hot spring are dacite, andesite and Quaternary volcanic tuffs. Their main rock forming minerals are quartz, plagioclase, biotite and rarely amphibole. The host rocks of Toptapan mineral water spring are Cretaceous and Jurassic sandstone, shales and carbonate sedimentary rocks. Their main rock forming minerals are quartz, calcite, dolomite and clays. Due to the deposition of mineral water springs, travertine is the main Quaternary sediments around the springs. Water samples were collected from Toptapan mineral spring and Lighvan hot spring in July (dry season). The sampling method was according to standard methods for geochemical analysis. Field parameters such as PH, temperature, and EC were measured in situ, and samples were analyzed by ICP-OEC and ICP-MS in the laboratory of the Geological Survey of Iran. The measuring data showed that pH varies between 6.1 to 6.4. The surface temperature varies from 20.1˚C to 32.8˚C. The concentration of anions and cations in the Piper diagram show calcic bicarbonate type for Toptapan mineral spring and sodic bicarbonate type for Lighvan hot spring respectively. According to Lunglier – Ludwig diagram, the dissolution of carbonate and silicate minerals is the most important factor in increasing calcic cation. The Cl-Li-B diagram shows that the dissolution of sodic minerals and clays and ionic exchange are also the most important factors for increasing sodium in these springs. These data are in agreement to the host rocks, their mineralogy and their chemical composition. Based on the Ca-Mg-K geothermometer diagram, the geothermal reservoir temperature for Lighvan hot spring is 95-100 ˚C with a depth of about 2Km and for Toptapan mineral spring is 65-85 ˚C with a depth of less than 1Km. Also, high concentrations of chlorine show a deep geothermal primary reservoir in the Lighvan hot spring. These geochemical data show that these cold and hot springs are not polluted and not harmful for environmental point of views.

This study presents a new approach to solve the one-dimensional solute transport equation with variable coefficients and two input sources in a finite porous media. The medium is divided into m-layers porous media with constant averages coefficients in each transport problem. The transport equations in layer i-1 and i are coupled by imposing the continuity of solute concentration and the dispersive flux at the interfaces of the layers. Unknown functions representing the dispersive flux at the interfaces between adjacent layers are introduced allowing the multilayer problem to be solved separately on each layer in the Laplace domain before being numerical inverted back to the time domain. The obtained solution was compared with the Generalized Integral Transform Technique (GITT) and numerical solutions for some problems of solute transport with variables coefficients in porous medium present in the literature. The results show a good agreement between both solutions for each of the studied problem. An example of application considering an advective-dispersive transport problem with a sinusoidal time-dependent emitting rate at the boundary was study in order to illustrate the effect of sinusoidal frequency on solute concentration.

Mining wastes occupy huge areas around the world, therefore, research aimed at their disposal and reclamation of disturbed territories is very relevant. We studied artificial soil based on neutralized ombrotrophic peat (Histosols Fibric) with different content (5% and 10% by weight) of copper smelting slag recycling waste ("technical sand"): finely dispersed (less than 0.05 mm), mechanically activated material. We analyzed the content of toxic element in peat, underground and aboveground parts of lawn grasses and potatoes. The coefficients of concentration and accumulation of elements were calculated. It was found that the introduction of 5% waste leads to exceeding the maximum permissible concentrations and approximately permissible concentrations (the regulated values for Russia) for zinc, copper, arsenic, antimony, and lead. The molybdenum content exceeds the Soil Quality Guidelines accepted in Canada, for selenium the values are at the limit level. The content of zinc, copper, cobalt, arsenic, molybdenum, antimony is significantly reduced (by 2-3 times) during the growing season. Ecological assessment of agricultural plants grown on artificial soil with 5% of "technical sand" showed that there are no excesses of the maximum permissible levels for any regulated element for potato tubers; a slight excess of arsenic was detected for lawn grasses. We additionally assessed the safety of potato tubers using the maximum permissible concentrations for food and established an excess of cadmium (3.4 times on the peat, with the addition of waste almost unchanged) and zinc (1.6 times on peat, 2.8 times for a peat with 10% waste).

The goal of this research was to investigate the efficacy photocatalysis with natural solar radiation and artificial UV radiation for disinfecting total coliforms in biologically treated wastewater.   The effect of TiO2 dosage and irradiation time on total coliform inactivation as measured by log reduction values (LRV), removal of BOD, COD, turbidity, and effluent properties as measured by pH and conductivity was investigated. Two sets of experimental equipment were constructed, one for using solar UV light and the other for using artificial UV light. After four hours of irradiation with 60 mg/L TiO2, photocatalysis achieved LRVs of 1.4 and 1, respectively, under UV and solar radiation. COD and BOD were reduced by 67% and 50% respectively under UV and solar radiation after two hours of irradiation with 60 mg/L TiO2. Turbidity was reduced by 71%. Both conductivity and acidity of the effluent were reduced as TiO2 concentration was increased. Photocatalysis with natural solar radiation produced disinfection results that were comparable to that of efficient UV light exposure. Artificial UV light and natural solar radiation can be combined in photocatalysis process to form a hybrid process.

Constructed wetland (CWs) systems offer an economical alternative to wastewater (WW) treatment in developing countries. So this study investigated lab-scale hybrid constructed wetlands (HCWs) with plant species Canna indica and Typha latifolia in mono and mixed culture for removing organic matter and nutrients from municipal wastewater (MWW) under arid climatic conditions. A HCW system consists of a storage tank feeding four series of vertical flow constructed wetlands (VFCWs) followed by horizontal flow-constructed wetlands (HFCWs). The results indicate that the planted beds performed better in removing suspended solids (TSS) (89.93% by Typha latifolia), biochemical oxygen demand (BOD5) (95.01% by mixed-culture), chemical oxygen demand (COD) (90.77 by Typha latifolia), nitrite (NO2-) (89.99% by mixed-culture), ammonium nitrogen (NH4+) (99.98 % by mixed-culture), and orthophosphate (PO43-) (87.22% by Typha latifolia) as compared to the unplanted bed for the same parameters (87.85%, 92.87%, 77.35%, 85.30%, 99.75%,  and 80.95%), respectively. The nitrate (NO3−) concentration in the effluent recorded the highest increase in the VFCW unit planted with mixed culture from 0.44 to 0.999 mg/l and decreased in the second stage to 0.588 mg/l at the HCW outlet. The mean values of the testing parameters in different HCW systems were not significant between the mono and mixed culture (P > 0.05), with a significant difference (P <0.05) between the VFCWs and HFCWs. The finding of this study demonstrated that Canna indica and Typha latifolia have been effective in WW treatment by HCW systems.

Boreal freshwater ecosystems are highly sensitive to pollution, but too little information is available on the use of both biotic and chemical indicators for estimation of the effect of wastewater on boreal rivers and streams. The purpose of this study was to assess the wastewater impact on the boreal river (Perm Krai, Russia).  Physicochemical parameters of major ions and trace elements were detected with a field portable unit, capillary electrophoresis, and ICP-MS. Fish data was collected by gillnets. To evaluate the level of pollution from the Tolych River upstream to downstream, we calculated heavy metal evaluation index (HEI), ecological risk index (ERI), and index of biotic integrity (IBI). The anthropogenic impact from upstream to downstream showed the range from a very high to medium level of pollution by ERI and from a high to medium level by HEI values, where most of the studied major ions and trace elements often exceeded aquatic life limits. We found significant thermal pollution of the observed river with the decreasing temperature gradient from pollution source down to the river mouth due to hydromorphological factors. Observed thermal pollution leads to the absence of thermally sensitive cold-water fish species and the abundance of ecologically flexible fish species. The water quality assessed by biotic IBI index showed low and very low quality of lower reach of the studied river, which contradicts the results of assessment by HEI and ERI indices.  The results show the importance of using aquatic organisms as bioindicators for assessing ecological water quality.

Discharge of synthetic dyes from industries without treatment leads to major environmental problems. Present research highlighted the Mn-doped ZnO along with UV-induced photo degradation of Congo red (CR) dye through batch study. The synthesized Mn-doped ZnO (MDZO) was characterized by Transmission electron microscope (TEM) and Fourier transform infrared spectroscopy (FTIR). The results revealed that MDZO along with UV exposure degraded the CR dye up to 99.3% at concentration 4 mg/L, pH (7), adsorbent dose (0.6 g/L) and contact time (30 min). The degradation data nicely fitted with pseudo-secondary kinetics and the thermodynamic study suggest the said reaction is exothermic in nature. A statistical method, central composite design (CCD) was used to screen out the optimized condition of dye degradation. The interactions of main factors and optimal conditions were also evaluated by 3D surface plots. The statistical output clearly demonstrates that the dye degradation data is nicely fitted with very high goodness of fit and F value (86.19). Present research clearly suggested that Mn-doped ZnO along with UV could be an effective treatment towards degradation of Congo red dye.

The simulation of photocatalytic reactor is conducted using computational fluid dynamics. Turbulence is described by using the RNG k-ε turbulence model. The DO radiation model is used to simulate the irradiance distribution in the photocatalytic reactor. The effects of operating parameters on the performance of photocatalytic reactor are considered. Results show that the degradation rate of oxalic acid decreases with the increase of inlet flow. The degradation efficiency decreases from 50% to 40% when the flow rate changes from 2.5 m3 h−1 to 10 m3 h−1. The degradation rate of oxalic acid can be improved by increasing the irradiance of the lamp. The degradation efficiency of oxalic acid in the photocatalytic reactor first reaches a maximum degradation efficiency with the increase of titanium dioxide concentration, and then decreases with the increase of titanium dioxide concentration. An optimal concentration of catalysts exists. The maximum degradation efficiency is 27% for the catalyst concentration of 20 µgL−1.

Gas storage is an important branch of technology that has many economic and environmental aspects. This technique could save gas to the need time and contribute to solving the CO2 and global warming problems. In this work, the structure and physicochemical properties of the prepared palladium complex were characterized in the solid and solution states using spectroscopic techniques. These examination methods include ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), metal and elemental analyses, and measurements of magnetic susceptibility and conductivity at room temperature. Also, findings on the surface morphology and surface area were provided via Field emission scanning electron microscopy (FESEM) and Brunauer–Emmett–Teller (BET) techniques, respectively. High-pressure adsorption measurements were investigated by storing carbon dioxide, and the results proved that such materials own remarkable gas adsorption properties that make them a good option for gas separation and storage. Gases uptake at 323 K for the complexes leads to the highest CO2 uptake. The prepared material could pave the road for further exploitation of similar materials.