Optimum Retention Time Research Articles

UNLOCKING THE POTENTIAL OF BIOENERGY: A SUSTAINABLE SOLUTION FOR ENERGY SECURITY, WASTE MANAGEMENT, AND ENVIRONMENTAL CONSERVATION

The study was carried out to generate biogas from fresh cowdung. Proximate analysis on the cow-dung sample revealed moisture content to be 60.53%, Ash content 11.01%, total solids 39.47%, volatile matter 10.78%, protein content 12%, nitrogen content 1.6%, carbohydrate 5.68% and fixed carbon 17.68%. The pH and Temperature were measured daily at 2:00pm, the temperature ranged from 30OC-38OC and the pH range was 6.7 - 7.2. The gas produced was measured daily by calculating the volume with the height increased daily up to 36 days. The results showed a typical biogas production curve, consisting of lag, acceleration, maturation, and decline phases. The optimal retention time for biogas production is identified as 20-30 days, during which biogas yields are highest. The findings indicate that microorganisms require an initial adaptation period (Days 1-3) before biogas production commences, followed by a significant increase in production (Days 11-20) and a stable production rate (Days 21-30). A decline in production is observed after 30 days. This study highlights the importance of retention time in biogas production and demonstrates the need for monitoring production kinetics to optimize retention time for specific substrates and microbial communities. The results have implications for the design and operation of biogas production systems.

Effects of Hydraulic Retention Time on Removal of Cr (VI) and p-Chlorophenol and Electricity Generation in L. hexandra-Planted Constructed Wetland-Microbial Fuel Cell.

Hexavalent chromium (Cr (VI)) and para-chlorophenol (4-CP) are prevalent industrial wastewater contaminants that are recalcitrant to natural degradation and prone to migration in aquatic systems, thereby harming biological health and destabilizing ecosystems. Consequently, their removal is imperative. Compared to conventional chemical treatment methods, CW-MFC technology offers broader application potential. Leersia hexandra Swartz can enhance Cr (VI) and 4-CP absorption, thereby improving wastewater purification and electricity generation in CW-MFC systems. In this study, three CW-MFC reactors were designed with L. hexandra Swartz in distinct configurations, namely, stacked, multistage, and modular, to optimize the removal of Cr (VI) and 4-CP. By evaluating wastewater purification, electrochemical performance, and plant growth, the optimal influent hydraulic retention time (HRT) was determined. The results indicated that the modular configuration at an HRT of 5 days achieved superior removal rates and power generation. The modular configuration also supported the best growth of L. hexandra, with optimal photosynthetic parameters, and physiological and biochemical responses. These results underscore the potential of modular CW-MFC technology for effective detoxification of complex wastewater mixtures while concurrently generating electricity. Further research could significantly advance wastewater treatment and sustainable energy production, addressing water pollution, restoring aquatic ecosystems, and mitigating the hazards posed by Cr (VI) and 4-CP to water and human health.

Characterization of bio-crude produced by graphene carbon tetranitrate catalyzed hydrothermal liquefaction and ultrasonication of Ulva prolifera mixed Chicken waste

<p style="text-align:justify;"><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">The utilization of macroalgae, specifically </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, for the manufacture of bio-crude demonstrates great potential as a viable alternative to conventional fossil fuels. This is mostly owing to its abundant availability and renewable characteristics, making it an optimal choice for bio-oil production. This study examined the synthesis of bio-crude through the Hydrothermal Liquefaction (HTL) method. The combination of Ultra-sonicated </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, Chicken Waste, and water facilitated the transformation of the moist biomass into Bio-crude. The study also examined the influence of process parameters, including the optimal operational temperature, retention time, and feedstock mixing ratio (275 <sup>o</sup>C, 30 minutes, and 1:4 ratio) for the graphene-C<sub>3</sub>N<sub>4 </sub>catalyst, KOH. The study's findings verified that a significant amount of bio-oil, specifically 23.5wt.% based on dry weight measurements, was successfully produced. The bio-oil mostly consists of alcohols, esters, phenols, ketones, and acidic chemicals. Furthermore, the bio-oil exhibited a significant heating value of 38.15 MJ/kg, which can be attributed to the presence of carboxylic acid groups and aliphatic hydrocarbons. Furthermore, the carbon content in the bio-oil was found to be double that of the macroalgae used as feedstock. Additionally, the heating value of the bio-oil was shown to be 2.5 times greater than that of the macroalgae. Hydrothermal liquefaction may be used to efficiently create bio-oil from </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, a third-generation fuel that has great potential as an environmentally benign and sustainable energy source.</span></p>

Selection of White-Rot Fungi for Decolorization of Palm Oil Mill Effluent and Evaluation of Biodegradation and Biosorption Processes

Ten species of white-rot fungi were evaluated for their ability to decolorization of palm oil mill effluent. The highest decolorization efficiency was found with Trametes elegans (PP17-06), followed by Ganoderma sp.2 (PW17-06) and Ganoderma sp.2 (PW17-177), respectively. T. elegans was further evaluated for the long-term performance of decolorization for 24 d. The optimal retention time for the decolorization was 8 d, with a color removal efficiency of 47.7%. Beyond 18 d of incubation, decolorization efficiency was reduced due to the autolysis of enzymes. During the biodegradation process, manganese peroxidase enzyme activities reached a maximum of 36.03 U.L−1. However, no significant laccase and lignin peroxidase activities were observed. T. elegans was also assessed for decolorization performance through biosorption on mycelial biomass. The synthesis of the enzyme was prevented by exposing the mycelium to HgCl2. Within an optimal contact time of 2 d, decolorization efficiency reached 12.5% with ADMI reduction from 4259.0 (±20.1) ADMI to 3727 (±104.04) ADMI. Results indicate that the adsorption capacity was reached at this time, and no significant color removal can be achieved by biomass. Results obtained in this study showed the potential of T. elegans in decolorizing palm oil mill effluent.

Performance evaluation of a novel multi-metal catalyst solution obtained from electronic waste bioleaching on upgrading and enhancing oil recovery

Due to the high costs and associated high CO2 emissions of thermal methods, this study focuses on upgrading heavy oil and enhancing oil recovery within reservoir temperature ranges. In this research, a novel, low-cost, and environmentally friendly multi-metal catalyst has been used, which is actually extracted from electronic waste (E-waste). At optimal conditions, which include 80 °C, 12 h of retention time, and 0.2 % v/v of the multi-metal catalyst, this catalyst effectively reduced the viscosity of heavy oil from 687 to 580 mPa.s. To analyze heavy oil before and after the process, Fourier transform infrared spectroscopy (FTIR) was conducted. FTIR spectra indicates that the multi-metal catalyst has reduced the amount of aromatic compounds, shortened hydrocarbon chains, and decreased double and triple bonds. Micromodel tests were conducted by multi-metal catalyst flooding at optimal temperature and retention time obtained from static experiments. Heavy oil recovery through multi-metal catalyst flooding reached 38 %, which is a 10.5 % increase compared to deionized water flooding. The contact angle of the rock was measured after contact with the multi-metal catalyst. The multi-metal catalyst reduced the contact angle by 55 °, changing the wettability of carbonate rock from oil-wet to water-wet. The absorption test indicates that the multi-metal catalyst dissolves certain metals in the rock, most likely due to the high pH of the catalyst. As a result, the permeability of the rock may increase due to the dissolution of the rock metals.

Biomimetic liposomes as a pH/ROS cascade-responsive nanoagent with high selectivity for breast carcinoma in photothermal therapy

With the recent advances in nanomaterials, photothermal therapies (PTT) enabled by deep-tissue penetration with novel nanoagents have offered a new hope for treating cancers. Nevertheless, PTT applications in conventional approaches remain translationally restricted due to their non-specificity and collateral pro-inflammatory effects during implementation. To address these drawbacks, we here report Lipo-PTO as the prototype of a new class of liposome-functionalized photothermal theragnostic agents, which can eradicate cancer cells in vivo with high selectivity. Lipo-PTO is activated by low pH and superoxide (O2•–) to specifically deliver and convert preloaded cyanine molecules to release Cy-NH in the tumour microenvironments, eventually enabling the activation of photothermal properties to induce tumour ablation. In further studies on Lipo-PTO for treating breast cancer (BC) in mouse models, Lipo-PTO usage was characterized by a high degree of biocompatibility, optimal retention time pharmacokinetics and tumour regression with minimal collateral damages. This study here thus illustrates an innovative strategy to target intrinsic attributes of tumour microenvironments for improved therapeutic precision and efficacy in PTT applications.

Assessment of solar photocatalytic degradation of textile wastewater by ZnO-based reactors

Abstract The present study deals with treating the textile wastewater of Jodhpur city in Rajasthan, India employing a photocatalysis technique. Jodhpur has a number of textile industries and efficient treatment of its effluents has been a major problem in the region. An effort has been made to resolve this issue through this study. A wastewater treatment unit was setup which involved coagulation and flocculation, sand filter, photoreactor, and activated carbon filter processes. ZnO-based semiconductor, coated on galvanized iron (GI) plates, served as a photoreactor. The water quality parameters removal efficiency at the end of each process operation was recorded for different detention periods in the photoreactor. Water quality parameters analyzed were biochemical oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS), and pH. The optimal retention time for the photoreactor was found and the BOD of the wastewater reduced to 25 from 740 mg/l (97% reduction), and TSS from 1,430 to 12 mg/l (99% reduction) for the corresponding retention time. TDS reduction efficiency was 25% and pH changed from 9.2 in raw wastewater to 8.4 in treated wastewater. Results show that the pilot treatment plant was efficient for BOD and TSS removal from the textile wastewater.

Calcium Reduction Using Variations of Thickness and Retention Time of Cocoa Shell Activated Carbon

High levels of hardness can lead to increased cases of kidney stones. Hardness levels can be reduced by using activated carbon from the cocoa rind as an adsorbent. The purpose of this research was to determine the variation of activated carbon thickness and optimum retention time in reducing the calcium content of dug well water, to determine the percent decrease in calcium ion levels at the optimum variation, and to determine the significance of the difference in the decreased in calcium levels between the treatment groups. The research method used the principle of adsorption of activated carbon from cocoa shells to calcium ions, which are activated by KOH. There were ten treatment samples with different variations of activated carbon thickness and retention time. The results showed that the thickness of activated carbon of 60 cm with a retention time of 50 minutes had the optimum ability to reduce the calcium content of dug well water. The percentage decrease in calcium levels reached 89,041 % with a decreased concentration of 234 ppm. The result of the statistical test showed a significance value of 0,05. The conclusion of the research is that activated carbon of cocoa shells can reduce calcium levels to the levels of soft water hardness, with variations in activated carbon thickness and retention time having a significant effect.

Continuous Synthesis of Monodisperse Spherical Silica Powder Using Tubular Reaction System

In the present study, monodisperse silica nanospheres were synthesized using a tubular reaction system in a continuous way. Screw-type blades were inserted inside a T-mixer for static mixing of the reactant streams which consisted of TEOS and NH4OH/H2O diluted with ethanol, for the continuous synthesis of the silica suspension. The diameter of the silica powder was monitored as a function of production time using dynamic light scattering to determine the optimum retention time and tube length, which were found to be 125 minutes and 7.5 m, respectively. The effects of reactant compositions on particle size were investigated by adjusting the amount of ammonia and water in the sol-gel reaction, which were then compared with the results from a batch reactor. Both the particle size and polydispersity index (PDI) of the silica suspension were measured to be comparable to nanospheres synthesized using a batch reactor. This implies that the tubular reaction system is more beneficial for potential industrial production applications in the size range from 115 to 310 nm, due to its continuous powder synthesis. The effect of the reaction medium was also studied, by replacing ethanol with methanol or propanol, indicating that the deviation in particle size with production time was not a serious issue in alcohols with lower molecular weight, such as methanol and ethanol.

Application of response surface methodology for COD and ammonia removal from municipal wastewater treatment plant using acclimatized mixed culture

This study aimed to optimize conditions influencing the removal of chemical oxygen demand (COD) and ammonia-N in municipal wastewater by using acclimatized mixed culture (AMC). Two-level factorial analysis was used to investigate the factors affecting the degradation of COD and ammonia-N (%); ratio of synthetic wastewater (SW) to acclimatized mixed culture (AMC) (1:1 and 3:1), presence and absence of support media (Yes and No), agitation (0 rpm and 100 rpm) and hydraulic retention time (HRT) (2 and 5 days). A central composite design (CCD) under response surface methodology (RSM) determined the optimum agitation (0 rpm and 100 rpm) and retention time (2 and 5 days). The best conditions were at 3:1 of SW: AMC ratio, 100 rpm agitation, without support media, and 5 days retention time. COD and ammonia-N removal achieved until 57.23% and 43.20%, respectively. Optimization study showed the optimum conditions for COD and ammonia-N removal were obtained at 150 rpm agitation speed and 5 days of retention time, at 70.41% and 64.29% respectively. This study discovers the conditions that affect the COD and ammonia-N removal in the municipal wastewater using acclimatized mixed culture.

Thermophilic anaerobic membrane bioreactor for pulp and paper primary sludge treatment: Effect of solids retention time on the biological performance

Lignocellulosic biomass is a promising renewable feedstock for the production of bioenergy and platform chemicals; however, its use would not be economically viable without adopting effective transformation technologies. In this work, long-term anaerobic treatment (370 days) of pulp and paper primary sludge (PS) was performed by a thermophilic anaerobic membrane bioreactor (AnMBR) for the first time to investigate the effect of various solid retention times (SRTs) on biogas production and solids reduction ratios. The tested STRs (32–55 days) have shown varying biogas productivity, and it can be concluded that the longer the SRT, the higher is the biogas yield. At the optimum solids retention time of 55 d, an organic loading rate of 2.15 ± 0.10 kg-TSS/L.d, and hydraulic retention time of 5 d, average biogas yield of 106.4 ± 8.5 m3 biogas/tonne TSS added (approximately 72.7 m3 CH4/t VSadded) was achieved with an average methane content of 56 ± 4% and the solids reduction ratio ranged between 47% and 54.9%. Besides biogas yield, the quality of the permeates, solids reduction, and digestates characteristic/dewaterability changed by changing the SRT. The mixed liquor suspended solids concentrations and solids reduction increased with increasing SRT, while the effluent COD concentration and sludge dewaterability decreased. The Fourier Transform Infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) findings exhibited that the digestate contains more lignin and cellulose than the other substances, while the nitrogen and carbon concentration decreased with increasing SRT.

Determination of optimum retention time in an air–cathode single-chamber microbial fuel cell batch-mode reactor by comparing different substrate types and concentrations

The disadvantages of the air–cathode single-chamber microbial fuel cell (AC-SCMFC) performance can be caused by numerous factors, and retention time (RT) is one such factor. It is difficult to conclude the ideal RT run for the specific tests under the same conditions. To determine the optimum RT for various types of microbial fuel cell (MFC), an AC-SCMFC batch-mode reactor was carried out by comparing different types and concentrations of substrates based on the main parameters of organic removal and power generation. The AC-SCMFC reactor was designed for the effective working volume of 500 mL and operated for 52 d in batch mode with factors being significantly correlated with the performance of the MFC reactor, which were two different substrates, sucrose and acetate, and three different chemical oxygen demand (COD) levels of 400; 1000, and 2500 mg/L (low, medium, and high, respectively) equipped with two graphene nanoplatelets (GNPs)-based electrodes connected to 100 Ω resistance and plugged onto a data logger. The results of this study indicated a significant pattern at the medium level, at which the optimum RT of sucrose was achieved at 24 h and that of acetate at 48 h. In comparison, the performances pattern at low and high levels of both substrates was insignificant to determine the optimum RT. For further application, the recommended RT for both substrates at any concentration is 24 h due to high overall performance, and the optimum RT established in this study could be applied to all types of MFC research, particularly in oxidizable or biodegradable organic ranges, which ensures high performance.

Biochar composite with microbes enhanced arsenic biosorption and phytoextraction by Typha latifolia in hybrid vertical subsurface flow constructed wetland

Arsenic contamination of ground water is a worldwide issue, causing a number of ailments in humans. As an engineered and integrated solution, a hybrid vertical subsurface flow constructed wetland (VSSF-CW) amended with BCXZM composite (Bacillus XZM immobilized on rice husk biochar), was found effective for the bioremediation of arsenic contaminated water. Biological filter was prepared by amending top 3 cm of VSSF-CW bed with BCXZM. This filter scavenged ∼64% of total arsenic and removal efficiency of ∼95% was achieved by amended and planted (As + P + B) VSSF-CW, while non-amended (As + P) VSSF-CW showed a removal efficiency of ∼55%. The unplanted and amended (As + B) VSSF-CW showed a removal efficiency of ∼70%. The symbiotic association of Bacillus XZM, confirmed by SEM micrographs, significantly (p ≤ 0.05) reduced reactive oxygen species (ROS) and malondialdehyde (MDA) accumulation in Typha latifolia, hence, increasing the plant growth (2 folds). An increase in the indole acetic acid (IAA) and arsenic accumulation in plant was also observed in As + P + B system. The removal efficiency of the system was compromised after 4th consecutive cycle and 48 h was observed as optimum retention time. The FTIR-spectra showed the involvement of -N-H bond, carboxylic acids, –CH2 stretching of –CH2 and –CH3, carbonyl groups, -C-H, C–O–P and C–O–C, sulphur/thiol and phosphate functional groups in the bio-sorption of arsenic by BCXZM filter. Our study is a first reported on the simultaneous phytoextraction and biosorption of arsenic in a hybrid VSSF-CW. It is proposed that BCXZM can be applied effectively in CWs for the bioremediation of arsenic contaminated water on large scale.

The Removal of Heavy Metals from the Leachate of Aged Landfill: The Application of the Fenton Process and Nanosilica Absorbent

Since leachate is typically composed of numerous constituents, its management requires special attention. After the raw leachate of Saravan in Rasht (Guilan Province, Iran) was transferred to a laboratory and its specifications were determined, it was subjected to experiments by the bench-scale method. The analyses of pH and heavy metals were performed in the main and control anaerobic reactors at time zero, before precipitation, and two hours after precipitation. After the anaerobic process was over and the optimal retention time was identified in the anaerobic reactor, the removal of heavy metals was analyzed by the Fenton process and nanosilica absorbent in leachate treatment. In the primary anaerobic reactor, the highest and lowest removal rates were 59 and 39% for Ni and Cu, respectively. In the Fenton process with optimal H2O2/Fe+2 ratio, Cu and Hg showed the lowest and highest removal rates of 22.4 and 54.54%, respectively. At the optimal rate of nanosilica absorbent and the retention time of 15 min, As was removed maximally with an efficiency of 38% and Cu was removed minimally. The results revealed that the integration of the anaerobic process with the Fenton process and nanosilica absorbent was very effective in removing heavy metals from the aged landfill leachate.

Digestate mechanical separation in industrial conditions: Efficiency profiles and fertilising potential.

The growing number of biogas plants has resulted in problems with the digestate management. In the studies carried out in industrial conditions in the biogas plant fed with sugar beet pulp, the influence of the decanter centrifuge operating parameters such as the retention time and differential speed on the effectiveness of digestate mechanical separation was evaluated. During the studies, the impact of the addition of cationic polyacrylamide flocculants with different charge density on the liquid and solid fraction composition was also determined. It was shown that the dry matter and organic matter concentrations in the solid fraction were about 88.80 g/kg FM and 66.20% DM, respectively and in the liquid fraction 25.50 g/kg FM and 77.00% DM after the centrifugation of the digestate without flocculant at an optimal retention time of 225s and differential speed of 4rpm. The removal efficiency of dry matter and organic matter was 32.00% and 39.39%. The best separation results were obtained centrifuging the digestate with addition of 20 g/kg DM flocculant with a charge density of 80%. The flocculant addition increased the removal efficiency of dry matter and organic matter in comparison to centrifugation without flocculant by 49.60% and 46.86%, respectively. After centrifugation and flocculation, about 60.83% of nitrogen, 74.55% of potassium and 33.23% of phosphorus remained in the liquid fraction. The liquid fraction contained lower concentrations of nickel, lead, cadmium and chromium in comparison to solid fraction.

HER2 fluorescent in situ hybridization signal degradation: a 10-year retrospective study.

Fluorescence in situ hybridization (FISH) analysis is recommended for invasive breast carcinomas with equivocal (2+) immunohistochemical expression of human epidermal growth factor receptor 2 (HER2). However, existing guidelines for the retention and storage requirements for HER2 FISH slides vary widely among countries and laboratories. To determine the degradation rateof HER2 FISH signals, and the optimal retention time and storage conditions for HER2 FISH slides. Dual-probe HER2 FISH slides from March 2009 to June 2019 were retrieved from the archive to assess the presence, intensity and quantity of the green chromosome enumeration probe 17 (CEP 17) and orange HER2 signals. Per the institutional policy, FISH slides are placed in slide boxes and stored in -80°C freezers for up to 4years, whereas older slides are stored at room temperature. After excluding HER2 FISH slides that were deemed uninterpretable due to technical issues, a total of 6255 slides were assessed. Slides from 2009 to 2014 were stored at room temperature, while slides from 2015 to 2019 were stored in -80°C freezers. Slides stored in freezers showed retention of both the green and the orange signals. Slide stored at room temperature demonstrated significant decrease in the signal retention rate and the loss of signal did not progress in a linear fashion. The CEP17 signal was quenched much faster than the HER2 signal. Our study is the first to demonstrate HER2 FISH signal degradation with time and slide storage conditions. Storing HER2 FISH slides in a -80°C freezer allows for retention of both HER2 and CEP17 signals. At room temperature, the signals start to degrade with CEP17 signals lost at a faster rate. The results of the study may be used in official guidelines for storage conditions and retention time for HER2 FISH slides.

Simultaneous removal of ammonia and volatile organic compounds from composting of dead pigs and manure using pilot-scale biofilter

ABSTRACT Odor emission is one of the most common problems associated with dead animals composting. Biofiltration treatment for eliminating exhaust odors formed during dead pigs and manure composting has been studied. The composting and biofiltration process consisted of two series of tests. Composting experimental trials lasted 6 weeks, and composting was performed using six pilot-scale reactor vessels. A total of 37 kinds of volatile organic compounds (VOCs) present in the air were identified, and temporal variations were determined during the 42 days of composting. Dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), and trimethylamine (TMA) were identified as the main odors VOCs component according to odor active values (OAVs). Nine biofilter vessels containing mature compost were used in studying the effect of different (30, 60, and 100 s) empty bed retention times (EBRT) on the simultaneous removal efficiencies (REs) of NH3, DMS, DMDS, DMTS, and TMA. Results indicated that the inlet concentration of NH3 applied was 12–447 mg m−3, and the average removal efficiencies were 85.4%, 88.7%, and 89.0% for EBRTs of 30, 60, and 100 s, respectively. The average REs of DMS, DMDS, DMTS, and TMA were 79.2%–95.4%, 81.9%–94.0%, 76.7%–99.1%, and 92.9%–100%, respectively, and their maximum elimination capacity (ECs) were 220, 1301, 296, and 603 mg m−3 h−1, respectively. The optimal EBRT for the stimulation removal of NH3, DMS, DMDS, DMTS, and TMA was 60 s. Implications: Dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), and trimethylamine (TMA) were identified as the main odors VOCs component during dead pigs and manure composting. Biofilter with mature as media can be used to stimulation remove NH3, DMS, DMDS, DMTS, and TMA, the optimal empty bed retention times EBRT was 60 s.

Method Development and Validation of Stability Indicating HPLC Assay for the Determination of Tenofovir Alafenamide Fumarate in Tablet Formulation

his manuscript describes the development and validation of a simple, isocratic, precise and accurate HPLC method for the assay of Tenofovir alafenamide fumarate (TAF) in tablet formulations. The previous reported methods were costly, less efficient, utilized temperature and pH conditions for method development, making it more complex while this method utilizes lower quantity of mobile phase, an C18 column to improve efficiency, retention and reproducibility of the method without using the conditions of temperature and pH. The mixture of buffer (0.1% trifluoroacetic acid): ACN (65:35 v/v) was used as a mobile phase with isocratic elution. C18 column (Syncronis C18 250 x 4.6 mm) having particle size 5µm was used at a flow rate of 1mL/min. The suggested method described a linearity range of 30-80 µg/mL and the correlation coefficient equals to 0.997 that determines the linearity between the concentration and absorbance. The tailing factor and plate count were found to be 1.03 and 12110 under the acceptable limits. According to ICH Q2 (R1) guidelines, all parameters were validated except LOD and LOQ. The drug was forcefully degraded by acid, alkali and oxidation. Validated result showed that the method was precise, cheap, isocratic, definite, less time consuming, robust and was degraded within the acceptable limits. No interference was observed in the placebo and blank injections hence the method proved to be specific. The optimum RT (retention time) value was found to be 5.8 min. A simple, efficient and economic method was developed with no use of temperature and pH. The suggested method can be applied as a market analysis of TAF in the tablet form.

Comparison of artificial neural network and multi-kinetic models to predict optimum retention time for dairy wastewater treatment in the integrated fixed-film activated sludge

ABSTRACT Dairy industry wastewater with high levels of nutrients and organic matters can adversely affect water bodies, and ecosystems. Therefore, there is an immediate need to treat such wastewaters before discharge. The dairy wastewater is acceptable to aerobic biological treatment. Given that these processes are generally failed by organic loading shocks, this work attains to solve the issue through innovative operation modes of integrated fixed-film activated sludge process for aiming to break high organic loads and better biodegradation of high-strength wastewaters. In order to achieve the purpose, two novel bioreactors were designed and operated with employing cycle times of 2.5–4.5 h at an OLR of 2.93–16.8 KgCOD/m3.d. The kinetic models and artificial neural networks (ANNs) were applied to reach a better realisation of the data and to predict the optimum retention time. The results show that the bioreactors obtained more than 97% of organic matter removal. In addition, based on kinetic coefficients, the high performance of the bioreactors is proved. Therefore, the investigated processes could be of interest as a suitable treatment process.

Highly efficient removal of victoria blue R and bioelectricity generation from textile wastewater using a novel combined dual microbial fuel cell system

A novel combined dual microbial fuel cell (MFC) system was developed for the continuous removal of Victoria Blue R (VBR) and electricity generation. Anaerobic and aerobic VBR-degrading bacteria, Shewanella putrefaciens and Acinetobacter calcoaceticus, respectively, were applied simultaneously. The effects of various factors on the performance of the novel system in the continuous mode were investigated, and optimal operating parameters for the system were determined. The optimal liquid retention time for continuous treatment was 36 h. The optimal external resistances of connected MFCs were 390 Ω and 1300 Ω. When artificial wastewater containing 1000 mg/l of VBR was fed continuously into the system, the VBR removal efficiency achieved was 98.7%. In addition, the acute toxicity of the effluent was decreased by a factor of 21.1–22.3, indicating that the system could detoxify VBR intermediates. VBR degradation involved a stepwise demethylation process, which occurred mainly in the first MFC, whereas aromatic ring opening, sequential deamination reaction, and carbon oxidation occurred mainly in the second MFC. When actual VBR-containing wastewater (75–262 mg/l) was introduced, the removal efficiencies of VBR, chemical oxygen demand, colority, NH3, and bioelectricity generation were >99.8%, >96.6%, >88.0%, 100%, and >194.8 mW/m2, respectively and the original inoculated strains remained dominant. Therefore, the combined dual MFC system could be applied to the treatment of actual VBR-containing wastewater.