Green Technology Approach Towards the Removal of Heavy Metals, Dyes, and Phenols from Water Using Agro-based Adsorbents: A Review.

The swift pace of socioeconomic development and climatic change have put significant strain on the quality of water resources. While, the bulk availability of agro-based materials arising from nature and agricultural practices has paved the way for researchers in eradicating toxic industrial pollutants such as dyes, heavy-metals, phenolic-compounds, pesticides, etc. by using them as adsorbents. In the area of pollution remediation, inventive technologies have been developing. The adsorption technique stands out among the other wastewater-treatment methods as it is simple, easy, efficient, and cost-effective. The agro-based adsorbents their use in this area contributes to minimizing natural waste. They can be employed in their original raw-form or after undergoing simple processes such as drying, grinding, and carbonization. Moreover, these adsorbents are typically modified physically or chemically to change their surface properties and improve their adsorption efficiency. The low-cost agro adsorbents have shown efficient adsorption capacities towards removing various organic and hazardous water pollutants. With a few exceptions, majority of adsorbents have demonstrated heavy metals, dyes and phenol removal efficiencies exceeding 90%. This review summarizes the available information and strategies for using agro-based adsorbents to eliminate hazardous water pollutants. It is a prospective area for research in the field of environmental pollution.

Preparation and characterization of biodegradable food packaging films using lemon peel pectin and chitosan incorporated with neem leaf extract and its application on apricot fruit.

The present study aims to develop and characterize biodegradable packaging films from lemon peel-derived pectin and chitosan incorporated with a bioactive extract from neem leaves. The films (PCNE) contained varying concentrations of neem leaf extract and were comprehensively assessed for their physical, optical, mechanical, and antimicrobial attributes. The thickness, moisture content, water solubility, and water vapor permeability of the biodegradable packaging films increased with the increasing concentration of neem leaf extract. Comparatively, the tensile strength of the films decreased by 42.05 % compared to the control film. The Scanning Electron Microscopy (SEM) confirmed that the resultant blended pectin-chitosan films showed a uniform structure without cracks. Furthermore, the analysis targeting Staphylococcus aureus and Aspergillus niger indicated that the films had potent antimicrobial activity. Based on these results, the optimum films were selected and subsequently applied on apricot fruits to increase their shelf life at ambient temperature. The findings, after examining factors such as colour, firmness, total soluble solids, shrinkage, weight loss, and appearance, concluded that the apricots coated by PCNE-5 had the most delayed signs of spoilage and increased their shelf life by 50 %. The results showed the potential applicability of lemon peel pectin-chitosan-neem leaf extract blend films in biodegradable food packaging.

Characterization of pea processing by-product for possible food industry applications.

Pea pods are by-products of the pea processing industries which are often disposed improperly but are rich reserves of nutrients. In this work, pea pod powder (PPP) was prepared and analysed for its nutritional, physical, functional and structural characteristics for food applications. Results showed that PPP contained 6.3% moisture, 5.2% ash, 3.5% crude fat, 13.3% crude protein, and 35.3% dietary fiber. Further, PPP exhibited 0.47 g/ml bulk density, 0.50 g/ml aerated bulk density, 0.62 g/ml tapped bulk density and had fair flowability as determined by Hausner's ratio and Carr's index. PPP also showed good functional characteristics with 3.24 g/g water absorption index, 7.9% water solubility index, 1.25 g/g oil absorption capacity, and 4.65% swelling power. Based on its excellent qualities, PPP was used to prepare cookies which were analyzed for its structural and spectral characteristics. The X-ray diffraction pattern of PPP and cookies revealed that the crystalline region in the latter remained intact. The FTIR spectra showed the presence of different functional groups in PPP and cookies. The study showed that PPP could be utilized as a beneficial ingredient in dietetic products such as baked goods due to its good water-holding capacity, oil-holding capacity and dietary fiber content.

Support vector regression-based model for phenol adsorption in rotating packed bed adsorber.

The excessive strength of phenol present in industrial wastewater is a major issue of concern to be looked upon. Among the pollutant removal techniques, a novel robust device, the rotating packed bed (RPB) adsorber, offers efficient adsorption of phenol due to its ability to magnify the mass transfer rate. In the present study, support vector regression (SVR) has been applied to predict adsorption of phenol on activated carbon in RPB by taking into account the independent parameters, namely, spray density, gravity factor, concentration, and contact time. The experimental data set of phenol adsorption sample has been randomized and normalized prior to constructing the models. The predictive ability of the SVR model has been compared with other data-driven models like artificial neural network (ANN) and multiple regression (MR) models. Both the SVR-based model and the ANN model have almost similar prediction efficacy; however, the ANN model was found to predict the outputs slightly better. The coefficient of determination (R2) and root mean square error (RMSE) values of test data set for the MR RPB adsorption model were found to be 0.934 and 0.149, while for the SVR and ANN-based models, these values were 0.996 and 0.045 and 0.998 and 0.027, respectively. Thus, it was concluded that the soft computing SVR and ANN models possessed tremendous potential to predict the adsorption process of RPB with remarkable accuracy and were greatly generalized.

gPROMS-driven modeling and simulation of fixed bed adsorption of heavy metals on a biosorbent: benchmarking and case study.

Adsorptive separation of heavy metals from wastewater is a viable approach to reuse it and avoid environmental pollution. The productive employment of adsorptive separation at a commercial scale, however, relies on the optimized conditions of an adsorber bed holding maximum and selective isolation of the heavy metals. The experimental route includes a significant trial and error approach, is time-consuming, involves operating cost, and remains economically unattractive. Contrarily, simulation of a mathematical model mimicking the adsorption system along with experimental validation can significantly minimize optimization efforts and suggests the best conditions of separation. In this work, a convective-dispersive model and adsorption model for fixed bed adsorption of copper (Cu), chromium (Cr), and cadmium (Cd) metals over wheat bran biosorbent are simulated using the gPROMS tool for benchmarking. The influence of feed flow rate, bed height, and metal concentration is studied, and breakthrough profiles of all heavy metals are predicted and matched with the literature. The error values (R2 and RMSE) and Chi-squared values determined from gPROMS simulations matched well with the previously available MATLAB-simulated data. After a successful benchmarking, we modeled pilot-scale adsorption of Cr on coconut coir (or Biosorbent) in a gPROMS simulation environment. A detailed method and algorithm of gPROMS simulation for Cr isolation is provided. The influence of feed flow rate, bed height, and initial metal concentration is studied on the breakthrough curves of the Cr. The optimum operating condition for the pilot-scale isolation of Cr from the water is suggested. The parameters, such as the axial dispersion coefficient and distribution coefficient, are determined.

A study on the shelf life of cookies incorporated with sapota and beetroot leaf powders.

The addition of edible fiber could affect the shelf life of cookies, which can have a positive or negative impact depending on the source of fiber. This study is in continuation of two previously published papers to investigate the storage stability of cookies incorporated with 4.5% beetroot leaf powder (BLP), with 7% sapota fiber powder (SFP) and reference cookies during 15 months at ambient temperature by analyses of physicochemical, microbial and sensory properties on each specified month using international standard methods. It was found that with increasing storage period, there was an increment in moisture content, peroxide value, free fatty acids and microbial population including total aerobic bacteria and yeast and mold colonies of all cookies; the lowest values being for cookies with 7% SFP (5.70%, 4.12 mEqO2/1000 g cookie's fat, 1.47%, 2.73 and 2.36 log CFU/g dried cookie, respectively). In contrast, the reverse trend was found in pH value. At the end of storage, a significant difference (p ≤ 0.05) was observed between reference cookies and other cookies regarding moisture content, peroxide value, free fatty acids and overall sensory acceptability; the quality of cookies supplemented with 7% SFP being desirable, followed by cookies with 4.5% BLP, and then reference cookies.

Postharvest quality assessment of apple during storage at ambient temperature.

In this study, the physical and chemical quality attributes of apples were measured experimentally during the storage after harvesting, using well-defined procedures and techniques. Overall quality index (OQi) models were formulated in terms of measured quality attributes. Firmness (F) and total soluble solids (TSS) varied from 11.88 ± 0.25 to 7.68 ± 0.24 N and 14.1 ± 0.1 to 12.7 ± 0.1 % Brix, respectively, whereas acidity and density varied from 0.163 ± 0.003 to 0.081 ± 0.001 % and 0.995 ± 0.003 to 0.951 ± 0.004 gm/cm3, respectively. The gloss values at 45° and 60° angles of incidence were found to be in the range of 7.9 ± 0.2 to 4.1 ± 0.3 and 6.8 ± 0.1 to 2.5 ± 0.3, respectively whereas, the Hunter color values L, a, b were found to be in the range of 51.75 ± 1.33 to 57.01 ± 0.98, 24.20 ± 0.86 to 30.12 ± 1.13, and 19.53 ± 1.61 to 22.96 ± 1.12, respectively. Formulated models were validated with the sensory scores. OQi predicted by the Model ML2 was found to be in consonance with the variation in the sensory overall quality scores. The OQi, as per the model ML2, was estimated as the ratio of the product of the constant C (265.5), acidity (A), and firmness (F) to the mod of the product of Hunter color values a and b. Finally, the predicted values of OQi were correlated with the measured quality parameters to check the possibility of predicting OQi non-destructively by using any one of those measured attributes during the storage.

Intensification and optimization of biodiesel production using microwave-assisted acid-organo catalyzed transesterification process.

To produce biodiesel cost-effective, low-cost, high free fatty acid (FFA) oil feedstock is desirable. But high FFA creates difficulty during the base-catalyzed transesterification process by yield loss due to the formation of soap. However, these problems are overcome by the use of an acid catalyst. The acid catalysts can directly convert both triglycerides and FFAs into biodiesel without the formation of soaps or emulsions. The shortcomings of mostly used inorganic acids are that they work well for esterification of FFA present in low-cost oil, but their kinetics for transesterification of triglycerides present in oils is considerably slower. Corrosion of equipment is another major problem associated with an inorganic acid catalyst. The usage of an organic acid catalyst of the alkyl benzene sulfonic type, like 4-dodecyl benzene sulfonic acid (DBSA) minimizes these disadvantages of inorganic acid-catalyzed transesterification. The aim of the present investigation was to reduce the reaction time of transesterification of triglycerides further by using microwaves as a heating source in the presence of DBSA catalyst to achieve higher conversions under mild operating conditions. To optimize the transesterification variables for the higher conversion of biodiesel, the response surface methodology was employed to design the experiment. By using the DBSA catalyst under microwave heating at a temperature of 76 °C, conversion close to 100% in only 30 min of reaction time was obtained using a 0.09 molar ratio of catalyst to oil and 9.0 molar ratio of methanol to oil. A modified polynomial model was developed and was adequately fitted with the experimental data and could be used for understanding the effect of various process parameters. The catalyst to oil molar ratio and reaction temperature created a stronger effect on the biodiesel production than that exhibited by the methanol to oil molar ratio. It was observed that the microwave heating process outperformed conventional heating, providing a rapid, easy method for biodiesel synthesis from triglycerides in the presence of DBSA, an organic acid catalyst. The produced biodiesel was of good quality, as all the properties were within the prescribed limits of the ASTM D6751 standard.

Development of models for prediction of the energy content of disposed MSW from an unsecured landfill.

This research was undertaken to estimate the energy potential of municipal solid waste (MSW) disposed over the past 15 years in an unsecured landfill located in Okhla, Delhi, India. The research collected a total of 98 samples from various depths and locations, which were analyzed for physico-chemical characterization. Multiple regression models for estimating the energy content of the disposed MSW were developed to predict average gross calorific value (GCV) and net calorific value (NCV). Forward entry regression was applied to identify the variables that contributed significantly to the regression. Thus, 4-parametric models and 2-parametric models were developed for predicting both average GCV and NCV of the disposed MSW. The developed models gave a reasonably good prediction of the energy content of MSW. Both the models gave low values of average absolute relative error and high values of correlation coefficient. It was found that the 2-parametric models exhibited nearly the same prediction ability with less measurable dimensions as the 4-parametric models. These models are unique and the research is a pioneering effort since apart from being the only models based on physico-chemical characteristics of disposed MSW to be reported, they also incorporate the effect of the depth of waste as an independent variable. The developed models can be used to predict calorific values of disposed MSW having similar characteristics in other landfill sites in India and abroad.

Comparative Effectiveness of Hands-on Versus Computer Simulation-Based Training for Contrast Media Reactions and Teamwork Skills.

PURPOSE: To assess the performance of interprofessional teams of radiologists, technologists, and nurses trained with high-fidelity hands-on (HO) simulation and computer-based (CB) simulation training for contrast reaction management (CR) and teamwork skills (TS). METHODS: Nurses, technologists, and radiology residents were randomized into 11 teams of three (one of each). Six teams underwent HO training and five underwent CB training for CR and TS. Participants took written tests before and after training and were further tested using a high-fidelity simulation scenario. RESULTS: HO and CB groups scored similarly on all written tests and each showed improvement after training (P = .002 and P = .018, respectively). During the final scenario test, HO teams tended to receive higher grades than CB teams on CR (95% versus 81%, P = .17) and made fewer errors in epinephrine administration (0/6 versus 2/5, P = .18). HO and CB teams scored similarly on TS (51% versus 52%, P = .66), but overall scores were lower for TS than for CR skills in both the HO (P = .03) and CB teams (P = .06). HO training was more highly rated than CB as an effective educational tool (P = .01) and for effectiveness at teaching CR and team communication skills (P = .02). CONCLUSIONS: High-fidelity simulation can be used to both train and test interprofessional teams of radiologists, technologists, and nurses for both CR and TS and is more highly rated as an effective educational tool by participants than similar CB training. However, a single session of either type of training may be inadequate for mastering TS.

Comprehensive Imaging Review of Abnormalities of the Placenta.

The placenta has a fundamental role in fetal health and functions as an important bridge to normal fetal development throughout pregnancy. A complete fetal ultrasound (US) survey should include full assessment of the placenta for any possible abnormalities. Placental diseases range from abnormal morphology, size, location, extent, and degree of placentation, to abruption and the presence of rare placental neoplasms of benign or malignant nature. Some of these conditions are associated with other diseases including aneuploidies, and their discovery should alert the radiologist to perform a very thorough fetal US examination. At times, a fetal karyotype may be needed to provide additional information. Timely detection of placental abnormalities can alert the clinician regarding the need to make important management decisions to reduce fetal and maternal morbidity and mortality. Familiarity with the normal and abnormal imaging appearance of the placenta is therefore necessary for the radiologist. Ultrasound with Doppler is the initial imaging modality of choice for placental assessment. Magnetic resonance imaging serves as a problem-solving examination in instances where the US findings are equivocal or where additional information is needed. Computed tomography has a limited role in the evaluation of placental disease because of its relatively limited tissue characterization and in particular because of the resultant direct radiation exposure of the fetus. However, in specific instances, particularly after trauma, computed tomography can provide invaluable information for patient management.

Evaluation of image registration in subtracted 3D dynamic contrast-enhanced MRI of treated hepatocellular carcinoma.

OBJECTIVE. The objective of our study was to quantify hepatic displacement between breath-holds in multiphasic contrast-enhanced MRI and assess the value of a 3D registration algorithm for displacement correction on subtracted images. MATERIALS AND METHODS. For this retrospective analysis, we evaluated MR images of 25 cirrhotic patients with treated hepatocellular carcinoma (HCC) and at least one coexisting small hepatic cyst that was hypointense on T1-weighted imaging. With the use of an automated 3D deformable registration algorithm, registered base and subtraction images were created using portal venous phase images as the baseline images. The relative displacement of the cysts over the dynamic phases was used to estimate hepatic displacement before and after registration. The width of the subtraction band artifact, HCC lesion conspicuity, and overall subtraction artifact level (i.e., image quality of the entire volume) of the subtraction images were evaluated before and after registration on a 5-point scale (1 = nondiagnostic, 5 = excellent image quality) by two blinded radiologists. Hepatic displacement and subtraction band artifact results were analyzed using the paired Student t test, and the results for HCC lesion conspicuity and image quality of the volume results were analyzed using the Wilcoxon signed rank test. Interobserver agreement was assessed using kappa statistics. RESULTS. The average total cyst displacement on unenhanced, arterial, and delayed phase images was significantly reduced by registration from 4.0, 3.2, and 4.6 mm, respectively, on pre-registered images to 2.4, 1.6, and 1.3 mm on postregistered images (p < 0.01). The mean HCC lesion conspicuity grade improved from 3.4 before registration to 4.4 after registration (p < 0.01), and the mean grade for image quality of the volume improved from 3.3 before registration to 4.6 after registration (p < 0.01). The average width of the subtraction band artifact decreased from 5.3 mm before registration to 2.4 mm after registration, from 6.1 mm before registration to 2.6 mm after registration, and from 5.2 mm before registration to 2.8 mm after registration for the arterial, portal venous, and delayed phase subtractions, respectively (p < 0.01). CONCLUSION. Automated registration of the liver in multiphasic MRI examinations reduced interphasic hepatic displacement, improved the conspicuity of the treated HCC lesion, and improved the overall subtraction image quality.

ASER Core Curriculum Illustration Project: coronal femoral condyle (Hoffa) fracture.

This is the 13th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for study online at http://www.aseronline.org/curriculum/toc.htm.

Errors of epinephrine administration during severe allergic-like contrast reactions: lessons learned from a bi-institutional study using high-fidelity simulation testing.

PURPOSE: To determine the most common errors of epinephrine administration during severe allergic-like contrast reaction management using high-fidelity simulation surrogates. MATERIALS AND METHODS: IRB approval and informed consent were obtained for this HIPAA-compliant bi-institutional prospective study of 40 radiology residents, fellows, and faculty who were asked to manage a structured high-fidelity severe allergic-like contrast reaction scenario (i.e., mild hives progressing to mild bronchospasm, then bronchospasm unresponsive to bronchodilators, and finally anaphylactic shock) on an interactive manikin. Intravenous (IV) and intramuscular epinephrine ampules were available to all participants, and the manikin had a functioning intravenous catheter for all scenarios. Video recordings of their performance were reviewed by experts in contrast reaction management, and errors in epinephrine administration were recorded and characterized. RESULTS: No participant (0/40) failed to give indicated epinephrine, but more than half (58% [23/40]) committed an error while doing so. The most common mistake was to administer epinephrine as the first-line treatment for mild bronchospasm (33% [13/40]). Other common errors were to administer IV epinephrine without a subsequent IV saline flush or concomitant IV fluids (25% [10/40]), administer an overdose of epinephrine (8% [3/40]), and administer epinephrine 1:1000 intravenously (8% [3/40]). CONCLUSION: Epinephrine administration errors are common. Many radiologists fail to administer albuterol as the first-line treatment for mild bronchospasm and fail to flush the IV catheter when administering IV epinephrine. High-fidelity contrast reaction scenarios can be used to identify areas for training improvement.

Core curriculum illustration: testicular torsion.

This is the 7th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http://www.aseronline.org/curriculum/toc.htm .

Comprehensive imaging review of abnormalities of the umbilical cord.

A complete fetal ultrasonographic (US) study includes assessment of the umbilical cord for possible abnormalities. Knowledge of the normal appearance of the umbilical cord is necessary for the radiologist to correctly diagnose pathologic conditions. Umbilical cord abnormalities can be related to cord coiling, length, and thickness; the placental insertion site; in utero distortion; vascular abnormalities; and primary tumors or masses. These conditions may be associated with other fetal anomalies and aneuploidies, and their discovery should prompt a thorough fetal US examination. Further workup and planning for a safe fetal delivery may include fetal echocardiography and karyotype analysis. Doppler US is a critical tool for assessment and diagnosis of vascular cord abnormalities. US also can be used for follow-up serial imaging evaluation of conditions that could result in fetal demise. Recent studies suggest that three- or four-dimensional Doppler US of the fetal umbilical cord and abdominal vasculature allows more accurate diagnosis of vascular abnormalities. Doppler US also is invaluable in assessment of fetal growth restriction since hemodynamic changes in the placenta or fetus would appear as a spectral pattern of increased resistance to forward flow in the fetal umbilical artery. Early detection of umbilical cord abnormalities and close follow-up can reduce the risk of morbidity and mortality and assist in decision making.

Prospective randomized study of contrast reaction management curricula: computer-based interactive simulation versus high-fidelity hands-on simulation.

PURPOSE: We developed a computer-based interactive simulation program for teaching contrast reaction management to radiology trainees and compared its effectiveness to high-fidelity hands-on simulation training. MATERIALS AND METHODS: IRB approved HIPAA compliant prospective study of 44 radiology residents, fellows and faculty who were randomized into either the high-fidelity hands-on simulation group or computer-based simulation group. All participants took separate written tests prior to and immediately after their intervention. Four months later participants took a delayed written test and a hands-on high-fidelity severe contrast reaction scenario performance test graded on predefined critical actions. RESULTS: There was no statistically significant difference between the computer and hands-on groups' written pretest, immediate post-test, or delayed post-test scores (p>0.6 for all). Both groups' scores improved immediately following the intervention (p<0.001). The delayed test scores 4 months later were still significantly higher than the pre-test scores (p ≤ 0.02). The computer group's performance was similar to the hands-on group on the severe contrast reaction simulation scenario test (p = 0.7). There were also no significant differences between the computer and hands-on groups in performance on the individual core competencies of contrast reaction management during the contrast reaction scenario. CONCLUSION: It is feasible to develop a computer-based interactive simulation program to teach contrast reaction management. Trainees that underwent computer-based simulation training scored similarly on written tests and on a hands-on high-fidelity severe contrast reaction scenario performance test as those trained with hands-on high-fidelity simulation.

Review of past research and proposed action plan for landfill gas-to-energy applications in India.

Open dumps employed for disposal of municipal solid waste (MSW) are generally referred to as landfills and have been traditionally used as the ultimate disposal method in India. The deposition of MSW in open dumps eventually leads to uncontrolled emission of landfill gas (LFG). This article reviews the MSW disposal practices and LFG emissions from landfills in India during the period 1994 to 2011. The worldwide trend of feasibility of LFG to energy recovery projects and recent studies in India indicate a changed perception of landfills as a source of energy. However, facilitating the implementation of LFG to energy involves a number of challenges in terms of technology, developing a standardized framework and availability of financial incentives. The legislative framework for promotion of LFG to energy projects in India has been reviewed and a comprehensive strategy and action plan for gainful LFG recovery is suggested. It is concluded that the market for LFG to energy projects is not mature in India. There are no on-ground case studies to demonstrate the feasibility of LFG to energy applications. Future research therefore should aim at LFG emission modeling studies at regional level and based on the results, pilot studies may be conducted for the potential sites in the country to establish LFG to energy recovery potential from these landfills.