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  Subjects -> WATER RESOURCES (Total: 160 journals)
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Journal of Water Chemistry and Technology
Number of Followers: 8  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1934-936X - ISSN (Online) 1063-455X
Published by Springer-Verlag Homepage  [2469 journals]
  • Photometric Analysis of Pentachlorophenol in Water by Extraction with
           Astrafloxin

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      Abstract: Pentachlorophenol (PCP) and astrafloxin FF (AF), a polymethine dye, were shown to form an ionic associate (IA), which could be rather perfectly extracted by different aromatic hydrocarbons. A maximum extraction of the ionic associate was attained at pH 8–12, being in quite a good agreement with the data obtained by calculating the distribution diagrams of corresponding dye and PCP forms. The distribution diagrams of these forms were calculated and constructed by using the MarvinScetch software. The effect of the dye concentration on the absorbance of the toluene extracts of PCP–AF ionic associates was studied. The PCP recovery attained a maximum at a dye concentration of (1.6–2.8) × 10–4 M. Extraction equilibrium was established for 50–60 s. The stoichiometry of the PCP–AF ionic associate was studied by the spectrophotometric methods of isomolar series and equilibrium shift, and the ratio of components was 1 : 1. The scheme of the formation and extraction of this ionic associate was proposed. The conventional molar absorption coefficient of the ionic associate was 1.2 × 105. The calibration curve of the extract absorbance as a function of the PCP concentration could be described by the linear equation А = 0.0121 + 0.0622c within a PCP concentration range of 1.2–60.3 μg/cm3. The PCP detection limit calculated by the 3s-criterion (n = 5, Р = 0.95) was 1.08 μg/cm3. The intralaboratory disperancy of the calibrating plot for PCP analysis with astrafloxin was estimated by the Cochran test G. The calculated Cochran test (n = 5, P = 0.95) was smaller than its tabular value: Gcalcd = 0.27 < Gtab = 0.64 to argue for variance homogeneity. A method for the extraction photometric analysis of pentachlorophenol in water and bottom sediments was developed.
      PubDate: 2022-06-01
       
  • Treatability and Kinetic Study of Dairy Effluent Using Microalgae
           Spirulina platensis in a Laboratory Scale Batch Reactor

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      Abstract: Purpose of this research work is to evaluate the bio kinetic coefficients of a pretreated Dairy wastewater in a suspended growth batch reactor with the treatment of microalgae Spirulina platensis. The study was performed in a laboratory scale batch setup. Samples of dairy plant was collected and it was pretreated with a consortium of carbon oxidation and nitrification process with bacterial culture that was made as the feed of this purification process. Bacterial pretreatment was done in order to reduce its organic carbon and ammonium nitrogen content. Nitrate nitrogen which was formed during bacterial treatment process and most of the phosphate still remaining in the water was treated in this process with micro algal species to remove these nutrients in wastewater and consequently to meet with discharge standards of regulatory authorities like Central Pollution Control Board (CPCB) of India and World Health Organization (WHO). A simulated synthetic wastewater sample was prepared according to the concentration measured in the original pretreated-wastewater where average nitrate nitrogen concentration was found 54 mg/L and phosphate concentration was 16 mg/L. The maximum 99.00 and 90.38% of nitrate nitrogen ( \({\text{NO}}_{3}^{ - }\) -N) and phosphorus ( \({\text{PO}}_{4}^{{3 - }}\) -P) removal were achieved corresponding to initial nitrate nitrogen and phosphorus concentration of 54 and 16 mg/L respectively, with an initial inoculum concentration of microalgae Spirulina platensis of 0.8% v/v after 8 days of detention period in batch reactor. Kinetics study was also carried out to obtain bio-kinetic coefficient for nitrate nitrogen and phosphorus removal using microalgae Spirulina platensis in order to obtain kinetic constants (Y, Ks and k). The values of k, Ks and YN were found to be 21.74 per day, 1.61 mg/L and 0.011 g of biomass/mg of \({\text{NO}}_{3}^{ - }\) -N as N for nitrate nitrogen removal. Values of k, Ks and YP were found to be 14.49 per day, 16.63 mg/L and 0.052 g of biomass/mg of \({\text{PO}}_{4}^{{3 - }}\) -P as P for \({\text{PO}}_{4}^{{3 - }}\) -P removal. Corresponding kinetic coefficients were compared to studies done by other researchers which corroborate the findings of this present investigation.
      PubDate: 2022-06-01
       
  • A Model-Based Approach to Study the Effect of Temperature in Plant-Wide
           Biological Wastewater Treatment Plants

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      Abstract: The effect of temperature on phosphorous, nitrogen, organic matter removal, overall effluent quality, methane, and hydrogen production in an activated sludge system (ASS) is assessed in this research. For the plant-wide model of the ASS, benchmark simulation model (BSM2-P) with an ASS (ASM2d) is used and the temperature is selected between 10 to 35°C covering different seasons. A steady-state simulation is carried out to evaluate the effluent compositions by changing kinetic parameters. A total of fourteen kinetic expressions for the maximum growth rate of heterotrophic biomass, autotrophic, phosphate accumulating organisms and their decay rates, oxygen saturation, hydrolysis, fermentation and oxygen mass transfer coefficients are also considered. Improved removal efficiency of NH, TN, TP, COD, and BOD5 is obtained at 17, 20, 10, 20, and 28°C temperatures respectively. The average percentage of removal is obtained as 22.2, 9.7, 28, 1.7, and 86.4% respectively for NH, TN, TP, COD, and BOD5 which is higher when compared to the removal rate at 15°C. Further, the anaerobic digestion model (ADM1) is also used with changing physico-chemical parameters which are functions of temperature. The corresponding physico-chemical parameters are analysed in the range of 25 to 55°C. A total of seven physico-chemical kinetic expressions for the acid-base equilibrium gases are considered which includes Henry’s law coefficient for carbon dioxide, methane, hydrogen, and partial pressure of water. At higher temperature (55°C) the ADM1 showed improved production efficiency rates for carbon dioxide and hydrogen but at lower level (25°C) it showed lower production efficiency rates. The average production rates of methane, hydrogen, and CO2 at 55°C different by –0.01, 54.1, and 7.8% respectively when compared at temperature of 28°C. This knowledge of varying temperature leads to the operator to handle biological treatment for wastewater in a quality manner with an optimal operational cost.
      PubDate: 2022-06-01
       
  • Isolation and Identification of Benzoate Degrading Bacteria from Food
           Industry Effluent

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      Abstract: Sodium benzoate, the sodium salt of benzoic acid, is the first accepted and one of the widely used chemical preservatives in the food, cosmetic and, beverage industries. In recent past, soaring demand of packaged food resulted in increased industrialization and intensified use of chemical preservatives. The residual remains of these industries are discharged into their wastewater treatment plants (WWTP) and effluent treatment plants (ETP) thus concentrating the chemical preservatives in these treatment plants. This causes harmful effects on the growth of indigenous microbes in treatment plants and reduces the effectiveness of biological processes in secondary wastewater treatment. Therefore, it is necessary to degrade preservatives like sodium benzoate in the WWTP/ETP of industries. The ETP samples were collected from food processing industry for the isolation of sodium benzoate degrading aerobic bacteria. The microscopic analysis of the isolate with maximum ability to grow at a very high concentration of sodium benzoate (10 000 mg/L) showed it to be Gram-positive, endospore forming bacteria. The molecular characterization was done using 16S rDNA sequencing with universal primers and the isolate was identified as Bacillus subtilis DSSK1. The sequence was submitted to NCBI GenBank with accession number MT704505. The isolate was able to utilize sodium benzoate as the sole carbon and energy source. It was able to degrade 76% of sodium benzoate (10 000 mg/L) in 72 h. It was also able to produce hydrolytic and oxidative enzymes (cellulase, amylase, pectinase and laccase) which can help it to better survive in the food industry effluent rich in cellulose, starch, pectin, and lignin thus making it a promising candidate for industrial effluent treatment rich in benzoate.
      PubDate: 2022-06-01
       
  • Inhibition of Multi Drug Resistant Bacterial Species, Scandinavium
           goeteborgense CCUG 66741 and Aeromonas veronii CRC6 Isolated from a Waste
           Water Treatment Facility Using Nanocomposites

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      Abstract: Antibiotic resistance is currently one of the most serious challenges to global health and socio-economic development. New resistance mechanisms are arising and spreading throughout the world, posing a danger to our ability to treat common infectious diseases. Antibiotics are released into the environment mostly through wastewater treatment plants. Antibiotics’ presence may favour the selection of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB). ARBs were isolated from a treated municipal wastewater sample. The resistant bacteria which were morphologically different and more in numbers were tested for multiple drug resistance. Two colonies were found to be resistant to the antibiotics, ampicillin, erythromycin, rifampicin, and chloramphenicol. These bacterial colonies were identified as Scandinavium goeteborgense CCUG 66741 and Aeromonas veronii CRC6 using 16S rRNA gene sequencing. These bacteria were also found to be sources of high-risk contamination with Multiple Antibiotic Resistance (MAR) Index of 0.6. They are not only multiple drug-resistant but human and animal pathogens. Further, they were evaluated for inhibition by nanocomposites (Ag0NP@GO and Ag0NP@rGO) at 500 mg/L using the agar well diffusion method. Both the bacteria were inhibited by the nanocomposites, showing a significant clearing zone with more inhibition caused by Ag0NP@rGO. Overall, the antibacterial action of the synthesized nanocomposite can be probably explained as the “Trap and Kill” mechanism. In particular, GO nanosheet with 2D structure and surface functional groups and charges help to bind the bacterial cells like a trapping agent whereas, silver nanoparticles embedded in GO sheet inactivate the bacterial cell. Growth curve analysis also showed a longer lag and a shorter log phase in the presence of nanocomposites, indicating effective antimicrobial activity.
      PubDate: 2022-06-01
       
  • Fabrication and Characterization of Low-Cost Tubular Ceramic Membrane for
           Microfiltration of Oily Wastewater

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      Abstract: The presence of notable quantities of oil in water is one of the prime causes of water pollution worldwide. The increased water pollution is creating nuisance to human and animal lives. To put an end to this threat, the treatment of oily wastewater is attracting everyone’s attention. The high efficacy of membrane filtration in separation operations makes researchers consider this technology for use in oily wastewater treatment. Hence, keeping this perspective in mind, tubular configuration membranes were fabricated using kaolin (30 wt %), quartz (30 wt %), calcium carbonate (28 wt %), boric acid (4 wt %) and feldspar (8 wt %). Membrane fabricated with this composition is found to possess a porosity value of 59.27 ± 1.002% and mechanical strength of 14.708 ± 2.603 MPa along with an average pore size of 0.092 μm. The surface of the membrane is smooth and free of any defects as observed under field emission scanning electron microscope. The membrane, due to its satisfactory physical and mechanical properties, is further used for the treatment of oily wastewater with three various concentrations and complete rejection of oil is achieved for all the concentrations. The successful separation of oil from the oily wastewater signifies size exclusion to be the dominant phenomenon for the rejection performance of the membrane. The droplet size distribution of the oil-in-water emulsion using laser particle size analyzer also reveals the same, with an average droplet size of oil lying between 2.884–3.802 μm for all three concentrations. The size of the droplets is far bigger than the average pore diameter of the membrane, which ultimately helps the membrane in retaining the oil content of wastewater. Therefore, looking at the outstanding oil removal efficiency of the membrane, it can be concluded that the membrane can be used industrially for the treatment of oily wastewater.
      PubDate: 2022-06-01
       
  • Estimation of Returned Sludge Using Artificial Neural Network and Fuzzy
           Inference System (Case Study: Shahrake-Gharb Waste Water Treatment Plant,
           Tehran)

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      Abstract: The amount of returned sludge is considered as one of the important and controllable parameters in the operation of wastewater treatment plants and play a vital role in process. There are different approaches to measure the rate of the returned sludge from secondary sedimentation to aeriation tank but all of them rely on the results of tests that are done after the process. Therefore, determining dynamic estimation methods is very important. In the present study, artificial neural network (ANN) models and adaptive fuzzy-neural inference system (ANFIS) were used to achieve this goal. First, different compositions according to the quality parameters of wastewater such as sewage inlet flow, BOD5, temperature, TDS, TS and returned sludge flow with time delay were considered as input, and the amount of returned sludge as network output. Then, by training the network and determining the desired structure based on the type, number of membership functions and related laws, and using MATLAB software, the most appropriate model were obtained based on statistical data, the mean squared error and the efficiency of the coefficient of determination model. As a result, the inputs were introduced as the most suitable model by combining a one-dimensional Sugeno inference system with relevant membership functions. The results of different methods were compared and finally, a Genfis2 model, which is moderation of ANFIS systems, with a training coefficient above 93% (MSE = 0.0081 and RMSE = 0.0898) and a validation coefficient above 91% (MSE = 0.0027 and RMSE = 0.0518) was selected and presented for accurate estimation of the amount of returned sludge up to the next 24 h. This study was done with comprehensiveness and practicality for the first time in Iran and could lead to prevention of polluting the receiving waters.
      PubDate: 2022-06-01
       
  • Comparing the Efficiency of Photocatalytic Humic Acid Destruction in Water
           with Oxygen and Hydrogen Peroxide on (N,Fe)-Doped Titanium Dioxide Samples
           in Different Irradiation Modes

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      Abstract: Titanium dioxide, one of the most important photocatalysts for the oxidation of compounds dissolved in water, is active only under ultraviolet irradiation and inactive in the visible spectral region due to its broad bandgap. A promising strategy for the creation of active TiO2 samples able to efficiently utilize visible sunlight and thereby to essentially decrease the cost of the photocatalytic treatment of natural and waste water is the introduction of several dopants. The efficiency of nitrogen doped and nitrogen and iron ion codoped titania samples synthesized by the sol-gel method with a bandgap narrowed to 2.59–2.99 eV in the photocatalytic destruction of humic acid (HA) in water (C = 55–60 mg/dm3) with atmospheric oxygen and hydrogen peroxide was studied depending on pH and a radiation source: an SVD-120 mercury quartz lamp (λ > 200 nm) or a GE CMG70 metal halide lamp (λ > 360 nm). The efficiency of doped TiO2 samples in the photocatalytic oxidation of aqueous HA solutions depended on the iron content (0–1% of Fe), the used oxidant, pH of the medium, and the irradiation mode. A much higher degree of HA destruction was attained in an acidic medium (pH0 2.4) as compared to a neutral medium (pH0 7) in both irradiation modes. The application of hydrogen peroxide increased the degree of photocatalytic HA mineralization in the presence of all the synthesized samples in both irradiation modes as compared to the oxidation with dissolved oxygen and essentially approached the efficiency of synthesized photocatalysts to standard Degussa P-25 TiO2. On the whole, N-TiO2 was most active among the synthesized photocatalysts. No clear dependence of the HA destruction degree on the Fe content in the samples (Fe,N-TiO2; 0.25–1.0%) were established at studied destruction parameters. In general, the codoped samples (Fe,N-TiO2) essentially inhibited HA destruction and, in a neutral medium, the inhibiting effect became stronger with increasing iron content in a sample in both irradiation modes. It seems probable that the recombination of photogenerated electron–hole charge carriers was intensified due to the selected method of N-TiO2 codoping with Fe3+ ions or the range of dopant concentrations.
      PubDate: 2022-06-01
       
  • A Feasibility Study on Synergistic Effect of Radical Sulfate Activated by
           Ozone on Explosive Degradation by Performance of Taguchi Design Method

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      Abstract: Millions of tons of nitroaromatic explosives are produced worldwide for military purposes and other applications. These substances lead to the accidental release of energetic materials, resulting in soil and groundwater pollution. Nitroaromatics are easily reducible because of their polarized N–O bands. Therefore, they are not sorbed strongly in the environment due to the intermediate character between hydrophobic and hydrophilic properties. Advanced oxidation processes (AOPs) have recently been used to degrade emerging pollutants due to generating highly oxidizing agents, such as hydroxyl radical. The main objective of this study is to examine the possibility of the persulfate/ozone (as an activator) process in explosive degradation from an aqueous solution. Experiment designs and data analysis were evaluated using the Taguchi design method considering COD and TOC removal as responses. Next, 2,4,6-trinitrotoluene (TNT) residual concentration was detected using the HPLC instrument. Finally, the most significant parameters that affected response removal were determined by variance (ANOVA) analysis. A satisfactory agreement of the quadratic model with the experimental data was confirmed by the high R2 value (close to 1). The correlation coefficient of 0.9 indicates the high validity of the obtained models for removing COD and TOC. Hence, in removing COD and TOC, a very good agreement was found between the experimental values and the predicted values of the responses. Two-third of 2,4,6-trinitrotoluene was transferred to inorganic compounds corresponding to CO2 due to the generation of oxidative species. More than 72% COD and 65% TOC removal efficiency were obtained in 60 min employing pH neutral, PS 19 mM, and 40 mg/L TNT (kt = 0.0191 min–1, pseudo-first-order kinetic model). Overall, sulfate radicals activated by ozone could be considered a promising process for nitroaromatic degradation of industrial effluent.
      PubDate: 2022-06-01
       
  • An Oxidoreductase Biomimetic System Based on CeO2 Nanoparticles

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      Abstract: With the current environmental concern on water waste related issues, there is a need to make aware of disposal wastewater safely and beneficially. This effluent can be used for agricultural purpose and it could be an important step for consideration of disposal in a proper way, treated and planned. The local studies are essential and needed to determine the quality of effluent in order to keep no loss in crop yields, soil and ground level water deterioration. Peroxidases have a wide potential in bioremediation of wastewater polluted with phenol derivatives, industrial effluents, decolourization of synthetic and natural dyes, elimination of endocrine disruptive chemicals, degradation of herbicides and pesticides, chlorinated dioxins, chlorinated alkanes and alkenes, polychlorinated biphenyls and chlorinated insecticides. Nowadays, the interest is preoccupied on nanozymes having peroxidase mimicking activities owing to their encouraging and favorable wide applications in biosensing, bioimaging and biomedicine. Brassica oleracea (broccoli) is a rich peroxidase source having activity 1.35 U/mL. UV-visible analysis and cyclovoltametric studies indicated that CeO2 NPs can substitute peroxidase under optimized conditions. CeO2 NPs efficiently oxidized α-naphthol, β-naphthol, anthracene and naphthalene with less oxidation potential respectively compared to peroxidase. On treatment of water effluent with peroxidase the value of BOD, COD and turbidity comes out to be 36, 60 mg/L and 10.03 NTU respectively. On treatment of water effluent with CeO2 NPs the value of BOD, COD and turbidity where lower and found to be 18, 28 mg/L and 5.4 NTU respectively. The result indicates that nanozyme efficiently degrades the phenolic and other aromatic compounds present in the waste distillery water discharged.CeO2 NPs behave as a catalyst by boosting the peroxidase activity twice. This preliminary study demonstrated that nanoparticle treatment of wastewater is more effective than enzymatic treatment and its use will be a cost-effective substitute to conventional technologies in India.
      PubDate: 2022-06-01
       
  • Direct Sunlight Driven In2S3 Thin Film Based Water Treatment Proto-Type

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      Abstract: A multi-faceted energy intensive technology that can be used for water disinfection and synthesis of electrolysed water (EW) is the need of the hour to achieve a sustainable post COVID 19 water management strategy. Direct sunlight driven processes are legislatively green technologies and hold the key in environmental sustenance. The development of a laboratory proto type reactor powered by a photovoltaic module for the treatment open source river water is described in this paper. This paper reports on the efficacy of the developed proto type technology for multipurpose application namely: (1) the production of Electrolysed water (EW) in a cost efficient manner using direct sunlight and (2) the removal of organic impurity from water using direct sunlight without the use of any photo catalyst or membrane. The prototype reactor utilizes chemical spray pyrolysis deposited highly photo-conducting indium sulphide thin films grown on fluorine doped tin oxide (F:SnO2) substrate (coated using chemical spray pyrolysis technique in-house) as the photo electrode. Dissolved organic matter arising in river water has distinctive fluorescence properties, and this research has utilized it to identify dissolved organic substances in both random samples and treated water. The work proves that photovoltaic module powered electrolytic reactors consisting of In2S3 electrodes can be used for treatment of river water. A diaphragm free, energy intensive route for the production of electrolysed water with the use of non-hazardous NaCl as the electrolyte has been demonstrated here. We conclude that In2S3 electrodes can be used for non-photo catalytic reduction of humic-derived impurities in river water. These results are also encouraging on the prospects of treating Nitrates present in the river water. The likes of techniques as described in this report that do not use photo catalyst or membranes may pave way for real time photovoltaic module powered floating reactors that can decontaminate water bodies on a large scale. The technique used by us demonstrates that a chlorine free route can be optimized for the synthesis of EW eliminating the production of large amounts of wastewater with high levels of biological oxygen demand (BOD).
      PubDate: 2022-04-01
       
  • Chemical Modification of Polyamide Thin-Film Composite Membrane by Surface
           Grafting of a Vinyl-Based Monomer

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      Abstract: Currently, the use of membrane techniques has undergone dynamic growth, particularly due to the diversification of their fields of application. This trend is expected to increase owing to new environmental protection requirements and thanks to the increasingly competitive energy and technical-economic performances offered by membrane processes. New research is constantly being carried out to better understand the functioning of membranes, to create more efficient or more specific membranes, and also to develop processes for new applications. The aim of this work is to improve the performance of a polyamide reverse osmosis membrane by chemical modification of its surface. Thin film polyamide reverse osmosis membranes are widely used for desalination. However, these membranes face a fouling issue that results in low permeation flux, which is undesirable in the reverse osmosis process. An interesting alternative to improve the properties of these polyamide composite membranes is the use of chemical surface modification. In this context, we studied the chemical grafting of vinyl acetate monomer on the surface of a polyamide membrane in order to improve the selectivity towards sodium ion. The chemical grafting was carried out by radical polymerization of vinyl acetate monomer in the presence of benzoil peroxide as an initiator in an organic medium. Unmodified, modified membranes and evolution of the polymerization reaction were analyzed by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), interferometric electron microscopy, and contact angle. An application with a front filtration module was investigated to confirm the improved selectivity for sea water. This study revealed an improved efficiency of the reverse osmosis PA membrane after the grafting of polyacetate monomer on the active layer of this membrane.
      PubDate: 2022-04-01
       
  • Screening of Composite Flocculants for Food Wastewater Treatment

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      Abstract: Food wastewater contains abundant nutrition substances causing high biological load on the environment. Inorganic and organic synthetic high-polymer flocculants have been most commonly used because of their flocculating efficiency and low cost. Natural organic flocculants possess a certain synthetic advantage. To investigate the optimal flocculant for food wastewater treatment, effects of five organic and chemical flocculants, being Chitosan (CTS), Polyaluminum sulfate (PAS), Polyaluminium chloride (PAC), Polyaluminum ferric silicate (PSAF), Polyacrylamide (PAM) and their pair composite flocculants by stirring have been studied. Under the condition of 300 rpm for 30 min by magnetic stirring apparatus, the optimal dosages of PSAF, CTS, PAC, PAM and PAS were 3.30, 2.19, 5.69, 6.56, and 3.30%, respectively. Therefore, effect of CTS was optimal because of its 87.24% maximal absorbance reduction. CTS demonstrates biodegradability and antibacterial activity, and the hydrophilicity introduced by the addition of polar groups is able to develop secondary interactions (–OH and –NH2 groups involved in H bonds with other polymers), which results in its excellent flocculant property. The optimal proportions of two components in composite flocculant A (CTS-PSAF), B (PAC-PAM), C (P SAF-PAC), D (PAS-PAM), E (CTS-PAS), F (CTS-PAM) were respectively determined as 0.53, 0.87, 0.46, 0.40, 1.33, and 1.67. Correspondingly, the optimal stirring speeds of every composite flocculant were 20, 20, 125, 125, 160, and 20 rpm. Thus, composite flocculant A was optimal due to 42.89% maximal CODCr removal efficiency and 51.54% maximal BOD5 removal efficiency (CODCr—chemical oxygen demand determined by potassium dichromate method). The results have presented that CTS and its pair flocculants CTS-PSAF are effective for food wastewater treatment, indicating that CTS-based flocculants exhibit effective pollution removal ability with wide applications.
      PubDate: 2022-04-01
       
  • Assessment of Water Quality and Ecological Condition of the Oster River

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      Abstract: Significant, multilateral, and long-term use of Ukraine’s water resources in various spheres of human activity has led to the deterioration of the state of many water management facilities and the complication of their operational regime. An unfavorable ecological situation developed in 2016 around the Oster River flowing through the territory of the Chernihiv region. This was caused by many factors of anthropogenic impact (intentional and unintentional) that have formed in the agricultural, industrial, housing, and communal sectors. A combination of these factors resulted in some changes occurring in the river ecosystem. The main goal of the present work is an analytical study of water quality in terms of hydrochemical indicators and an assessment of the ecological state of waters of the Oster River. The chemical composition of the surface waters of the city of Oster was analyzed, in particular, by stripping voltammetry for the concentration of heavy metal ions Pb2+, Cu2+, Zn2+, and Cu2+ and colorimetry for the concentration of total Mn2+, \({\text{NH}}_{4}^{ + }\) , \({\text{NO}}_{3}^{ - }\) , and \({\text{PO}}_{4}^{{3 - }}\) . Insignificant excesses of the water quality standard were found for fishery reservoirs in the concentration of organic substances in terms of chemical and biological oxygen consumption, ammonium ions, and phosphate ions. Pollution with ions of these heavy metals in water samples was not recorded, but the concentrations of lead and copper ions tend to increase. Exceeding the total iron and manganese indicators is typical for the Polesye rivers. These phenomena may result from anthropogenic loads and natural anomalies. A comprehensive assessment of the quality of surface waters based on the calculation of the water pollution index revealed that in 2018–2020, surface waters of the Oster River belong to Class III and are characterized as “moderately polluted.” The study results are useful for areas of water protection activities to improve the state of the Oster River and eliminate the negative consequences of anthropogenic impact.
      PubDate: 2022-04-01
       
  • Dynamic Model of Water Quality Evolution

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      Abstract: Spatiotemporal variability in water quality is often expressed so clearly that the variance of the monitored parameters exceeds their average value. This circumstance substantially complicates water management. It is practically important and theoretically interesting to find any dynamic trends in the processes of natural water quality evolution. These trends are difficult to detect with a linear approach to the evolution of quality parameters that are random in nature, but it is possible to take into account the nonlinearity of natural aquatic systems. The nonlinear logistic rule derived in this way enables estimation of the composition of water as a function of the intensity of the processes of its pollution and self-purification. It is shown that an aquatic ecological system shows linear behavior only in the case of slow processes when its parameters approach certain stable (equilibrium) values. With an increase in the intensity of pollution and self-purification processes, cyclic fluctuations of the monitored parameter occur. Their amplitude remains small at a low rate of pollution and increases with an increase in the pollution rate or even is accompanied by bifurcations with a further transition to total chaos. This is an indication of the substantial nonlinearity of natural aquatic systems, which is manifested, in particular, as energy dissipation of ordered processes and as bifurcations, i.e., unexpected changes in controlled parameters. In this case, order parameter fluctuations that determine singular contributions to the controlled dynamic characteristics serve as influencing nonlinearity factors. The performed theoretical analysis is confirmed by the observational data, which show that the aquatic ecological system under study has a noticeable degree of organization. The water management efficiency can be improved by taking these circumstances into consideration.
      PubDate: 2022-04-01
       
  • Exploration of Potential Indigenous Fungal Species for Mycoremediation of
           Industrial Effluent

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      Abstract: Lack of environmental friendly treatment of industrial effluent is a severe global problem. Microbial treatment may serve as potential technique to overcome the problem of environmental friendly management of industrial effluents. The present research was undertaken to find out potential indigenous fungal isolates/species from relevant industrial wastewaters and to explore their efficacy in mycoremediation of industrial effluent. Fungal species were isolated from textile, washing, dyeing, tannery and composite wastewaters, and efficient isolates were selected through screening against biobleaching of the effluent. Subsequently the selected fungal isolates were evaluated in mycoremediation of industrial effluent. Eleven fungal isolates were identified as species of Trichoderma, Penicillium, and Aspergillus. Finally, two species (M206 (Aspergillus sp.) and B102 (Penicillium sp.)) were used for mycoremediation. Significant improvement of biobleaching/bioremediation of treated effluent was noticed. After 5 days of treatment maximum 94 and 93% of turbidity, 48.45 and 38.14% of total solids (TS), 96.67 and 95.56% of total suspended solids (TSS), 36.98 and 36.12% of total dissolved solids (TDS) removal were recorded in treated effluent with prior grown fungal species of M206 and B102, respectively compared to control. Moreover, 72.93% chemical oxygen demand (COD) removal was also monitored by both species. Conversely, 93% turbidity and 89% TSS removal were recorded in fresh fungal spores suspension of M206, which were closer to the values obtained at 3 days prior grown treatment. Majority of the studied parameters suggested that the fresh fungal spores suspension exhibited superior performance in mycoremediation of effluent. Definitely fresh fungal spores suspension of M206 played superior roles in mycoremediation of the treated industrial effluent. Mycoremediation by fresh fungal spores suspension might be opened as a potential technique of industrial effluents treatment.
      PubDate: 2022-04-01
       
  • Determination of 2-Methylisoborneol and Geosminin Water by Using Stir Bar
           Sorptive Extraction-Thermal Desorption Coupled with GC-MS

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      Abstract: In water system, odorous compounds are often associated with the metabolites of microorganisms as fungi and blue-green algae, and the related compounds have been commonly found in lakes and reservoirs. Among those compounds, geosmin (GSM) and 2-methylisoborneol (2-MIB) have been treated as main odor compounds, which cause the off-flavor issues in natural sources such as freshwater, water reservoirs, marine water ecosystems and even in drinking water. Since of the strong smell of GSM and 2-MIB with earthy flavor and odor, they can be simply detected by human nose. Although those compounds are harmless to human health at certain level, high accumulation in natural water and drinking water led to an undesirable odor. Thus, the detection of the presence of those off-flavor compounds is first step to address above problem. To analysis the undesirable odorous compounds in water and aquaculture products, a concise and sensitive method has been developed by using stir bar sorptive extraction-thermal desorption coupled with gas chromatography-mass spectrometry (SBSE-TD-GC-MS) in the study. SBSE-TD-GC-MS has been optimized and validated through analyzing 2-MIB and GSM in aquatic samples. The calibration curves of 2-MIB and GSM were linear in the range of 0.5–100 ng/L (r2 > 0.995, RSDs < 3.5%). The limit of detection (LOD, S/N = 3) and limit of quantification (LOQ, S/N = 10) of 2-MIB and GSM were both ~0.2 and 0.5 ng/L, respectively. The recoveries of 2-MIB and GSM were 86–113% with good precision (RSDs < 8%) by spike in 2.5 and 25 ng/L standard compounds. This method was successfully applied to monitor and determinate the amount of 2-MIB and GSM in four types of water samples. Thus, SBSE-TD-GC-MS, a developed technique with high sensitivity and good recoveries, can be applied to detect odorous compounds at very low concentration, by using significantly smaller amounts of water samples, without any pre-concentration.
      PubDate: 2022-04-01
       
  • Investigation of Amoxicillin and Ciprofloxacin Behaviours in Sequencing
           Batch Reactor and Their Effects on Chemical Oxygen Demand Removal
           Efficiencies

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      Abstract: In this study, the behaviors of amoxicillin and ciprofloxacin were investigated in the conventional treatment systems in both theoretical and experimental manner. The doses of these pharmaceuticals which inhibit the treatment were determined. The efficiencies of amoxicillin and ciprofloxacin in response to dose increments were determined by monitorization of chemical oxidation demand parameter. Based on the results of these studies, amoxicillin doses >35 mg/L and ciprofloxacin doses >10 mg/L reduced treatment efficiency by leading changes in the structure of activated sludge. The sludge became sticky and dark due to the increase in the extracellular polymeric substance formation in the bacteria with increasing pharmaceutical concentration. The highest and lowest removal efficiencies were found as 39.8 and 14.9% for amoxicillin doses of 5 and 20 mg/L, respectively. The greatest part of the removal efficiency was achieved through adsorption in the sludge (33.8%). On the other hand, the highest and lowest removal efficiencies were found as 15.17 and 2.85% for ciprofloxacin doses of 30 and 75 mg/L, respectively. Again, the greatest part of the removal efficiency was achieved through adsorption in the sludge (11.83%). This indicates that removal mechanisms for both pharmaceuticals were sludge adsorption as amoxicillin and ciprofloxacin biodegradations were low at all doses investigated. To compare experimental data with theoretical estimations, pharmaceutical removal was calculated in Sewage Treatment Plant (STP) using EPI Suite program. According to experimental results, the total removal efficiencies were consistent with theoretical estimations calculated by Environmental Protection Agency (EPA) Draft Method. There may be inconsistency between theoretical estimations and experimental results due to differences in experimental conditions caused by microbiological behaviors in the theoretical conditions. The removal efficiencies for amoxicillin and ciprofloxacin calculated by default method were lower than those calculated by EPA draft method since biodegradability is not taken into consideration in the default method.
      PubDate: 2022-04-01
       
  • Investigation on Sol-Gel Facilitated Synthesis of Silica Nanoparticles
           Using Kariba weed (KW-NS) and Its Efficiency in Cr(VI) Removal

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      Abstract: Environmental pollution is an aggressive change in the surroundings mainly because of heavy metals, dyes and organic pollutants, which are responsible for crucial natural and health issues. The undiscerning industrial activities make the water resources inappropriate for utilization and the accumulation of these pollutants in water is accountable for harmful effects on aquatic plants and animals. An eco-benign approach was explored for the synthesis of silica nanoparticles (KW-NS) using waste aquatic weeds. In the present study, waste aquatic Kariba weeds were utilized to synthesize and characterize silica nanoparticles and to investigate their applicability in the removal of Cr(VI) ions from aqueous as well as industry effluent. The silica nanoparticles using Kariba weeds (KW-NS) were prepared using sol-gel method and characterized using SEM, FTIR and BET analysis. Various parameters such as pH, adsorbent dosage, initial metal concentration and contact time on the adsorption of Cr(VI) were investigated and optimized. Adsorption isotherm, kinetics, thermodynamics, and regeneration mechanism were studied to determine the efficacy of KW-NS. The adsorption equilibrium for Cr(VI) was achieved at an optimum pH of 4.3 with 4 g L–1 adsorbent dosage at 60 min with 10 mg L–1 metal ion concentration and maximum adsorption capacity reached up to 96.54 mg g–1. The applicability of the synthesized KW-NS was checked with the tannery and electroplating industry effluent and posed 72 and 60% removal efficiency, respectively. Results obtained from this study indicate that the waste aquatic Kariba weed has the potential to synthesize silica nanoparticles in a more efficient and economical way than the conventional synthesis. These nanoparticles can be effectively applied as an adsorbent to treat industrial effluents for heavy metal removal.
      PubDate: 2022-04-01
       
  • Preparation of Electrochemically Activated Water in the Presence of
           Dispersed Fillers

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      Abstract: Since the quality of surface water has significantly deteriorated, consumers of tap drinking water are forced to additionally purify it by using various filters or low capacity reverse osmosis systems. Water purified by reverse osmosis barely contains mineral salts that are necessary for the human body. The electrochemical method is among the available options for correcting the composition of water, which makes it possible to obtain water with specified characteristics by controlling the conditions of the electrochemical process. Thus, this method allows one to obtain water with a negative redox potential (ROP) that brings antioxidant properties to water. A two-chamber electrochemical apparatus with the electrode compartments separated by a perforated cartridge filled with dispersed materials of different nature, such as cation exchange resin KU-2, activated granular carbon AG-3, and quartz sand, is used to purify tap water. It is shown that the energy consumption is <0.1 kW h/m3 when using a cation-exchange resin. In the time while the initial tap water flow is supplied to the anode chamber, from which it then passes through the cartridge into the cathode chamber and further into the water storage container, the ROP value of water decreases to –100 mV. In this case, water softens and the content of calcium ions decreases from 58 to 2–5 mg/L depending on the electrical current.
      PubDate: 2022-04-01
       
 
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