Search

Dubinin–Radushkevich (D – R) isotherm remains one of the widely used adsorption models in solid/liquid interface. However, adsorption potential (ε), as a function of equilibrium concentration (Ce) and solubility (Cs) of adsorbate, is frequently expressed through a dimensionally inconsistent form i.e. ε = R T ln 1 + 1 C e , instead of the correct form i.e. ε = R T ln C s C e . Although Hu and Zhang (2019) have pointed out the misinterpretation, incorrect use of isotherm however continues. All of the 10 all-time highly cited articles on D-R isotherm and 80 out of 117 articles citing the work of Hu and Zhang (2019) adopted the incorrect or ambiguous form. Only six research articles have referred source of required Cs data, i.e. literature reported value, approximated to initial adsorbate concentration, or as an additional model parameter. Modeling of D-R isotherm using datasets extracted from three selected references suggests that using the incorrect expression would have a variable impact on maximum adsorption capacity estimates. However, sorption energy would invariably be overestimated (at least 200 times) in all data sets. In the absence of any unified approach and the practical difficulty associated with ascertaining the correct Cs value, researchers are inclined to use the inconsistent model. [ABSTRACT FROM AUTHOR]

The objective of this work was to explore an alternative way to manage the non-biodegradable and non-recyclable fraction of municipal solid waste (MSW) in Vellore city, India. Refuse-derived fuel (RDF) samples with different proportions of plastic, thermocol, foam and jute straw were formulated. The RDF samples were characterized in the form of heating values (proximate and ultimate analysis), surface properties through X-ray diffraction (XRD) and thermal stability through thermogravimetric analysis (TGA). The measured higher heating values (HHV) of four RDF samples varying between 6032 and 6168 kcal/kg were effectively modelled using various empirical models for the prediction of HHV based on their elemental analysis. Higher absolute weight loss in TGA was evident in samples with jute straw while the highest rate of weight loss was noted in samples with a higher proportion of thermocol. Results from this preliminary investigation of RDF samples prepared from non-biodegradable and non-recyclable fractions of MSW warrants an exhaustive analysis of a larger pool of samples to project appropriate RDF composition for better energy recovery. [ABSTRACT FROM AUTHOR]

The abundance of heat-trapping asphalt and concrete, smog, and heat emitted from buildings and vehicles is one of the major reasons for the prevailing high temperature, air and noise pollution in cities. Incorporation of green wall in buildings is considered to be an effective method to reduce temperature and mitigate environmental pollution. This study investigated and compared the performance of two types of climbing green wall (CGW) and paving green wall (PGW) vegetation for temperature and noise reduction. Besides, the biological characteristics of Parthenocissus tricuspidata and Sedum lineare Thunb were also analyzed to substantiate the temperature and noise reduction performance of these plants. The results revealed that, the average temperature reduction by CGW and PGW were 4.9% ± 1.3% and 16.6% ± 7.4%, respectively, under no irrigation condition, and 18.4% ± 9.4% and 23.8% ± 8.7%, respectively, under irrigation condition. The noise reduction by CGW in high (75–80 dB), medium (50–55 dB) and low (30–35 dB) sound pressure level was 12.4, 7.5 and 5.7 dB, respectively, and 15.6, 9.3 and 7.0 dB, respectively, by PGW. The results demonstrated that green wall has an excellent effect on buildings toward temperature and noise pollution reduction. [ABSTRACT FROM AUTHOR]

The main aim of this work is to test the performance of red mud as a permeable reactive barrier (PRB) material for fluoride removal from water. Batch experiments were carried out to optimise the fluoride removal efficiency (RE) of activated red mud (ARM) based on four selected parameters, namely, the initial fluoride concentration (3–40 mg/L), adsorbent dose (0.5–5 g/L), pH (3.0–11.0) and ionic strength (0.001–0.5 M). Statistical analysis of the results revealed the optimum conditions as initial fluoride concentration −21.46 mg/L, adsorbent dose −2.77 g/L, pH 7.01 and ionic strength −0.24 M, respectively. Under the optimum conditions, fluoride RE of 87.3% was achieved. The individual effects due to initial fluoride concentration, adsorbent dose and ionic strength on fluoride removal were highly significant (F = 59.69; P < 0.005); whereas adsorbent dose, pH and ionic strength showed the greatest squared effects (F = 26.05; P < 0.001). The interaction effect due to initial fluoride concentration and adsorbent dose was also found to be significant (F = 12.52; P = 0.002) for fluoride removal. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analyses were performed to identify the change in functional group and surface topography following red mud activation. [ABSTRACT FROM AUTHOR]

Artificial neural networks (ANN)-based multiple decision expert systems (MDES) were developed for assessing the performance of a boiler system. Different configurations of ANN were used with different decision combination methods, including a neural combiner, to propose the model. The model was developed using the plant data collected over a period of five months to predict steam temperature, pressure, and mass flow rate, using feed water pressure, feed water temperature, conveyor speed, and incinerator exit temperature as the input parameters. The predictive capability of the model is evaluated in terms of both correlation coefficient (R) and mean absolute percentage error (MAPE). The results observed from this work demonstrate that neural combiner and ANN-based MDES can efficiently predict the data on steam properties consistently, and that the model can serve as an efficient tool for monitoring boiler behavior under real-time conditions. Superiority of the proposed model over others under various scenarios is also demonstrated. [ABSTRACT FROM PUBLISHER]