Removal of chromium and Iron using mixed adsorbent for synthetic and industrial samples in a continuous column reactor

he results of the experiments showed that bed weight, flow rate, and initial metal ion concentration all play a role in the removal of Cr (III) and Fe (II). The optimized break through curve was obtained at 36cm bed height and 10ml/min for chromium where 97.5 to 100% removal was observed at a saturation time of 500-600 min. With the increase in bed height from 12cm to 36cm, both the breakthrough and saturation times for Cr (III) increased. The break through time at 12cm, 24cm, 36cm and 10ml/min for Cr (III) were 70 min, 105 min, and 35 min respectively. The saturation time for Cr (III) at 12cm, 24cm, 36cm and 10ml/min were 460 min, 490 min, and 500 min respectively. Similarly, the break through time for Fe (II) at 12cm, 24cm, 36cm and 10ml/min were 70 min, 80 min, and 100 min respectively. At 12cm, 24cm, 36cm, and 10ml/min, the saturation time for Fe (III) was 340 minutes, 360 minutes, and 430 minutes, respectively. Overall in the column performance comparison between synthetic solution and industrial effluents for chromium, synthetic solution performance was more superior at fixed volumetric flow rates of 10 ml/min and bed heights ranging from 12 cm to 36 cm But the reverse trend was observed in case of fixed bed heights of 36 cm (150 g) and variation of volumetric flow rates from 10ml/min to 30ml/min which indicates that industrial effluent performance was superior when compared to synthetic solution for heavy metal removal.

Study on Fluidization Characteristics of Magnetically Fluidized Beds for Microfine Particles

The bed pressure drop, minimum fluidized gas velocity, bed density, and bed expansion rate are important parameters characterizing the fluidization characteristics of gas-solid fluidized beds. By analyzing these parameters, the advantages and disadvantages of the fluidization state can be known. In this study, experiments were conducted to study the fluidization characteristics of a gas-solid magnetically fluidized bed for microfine particles by changing the magnetic field strength, magnetic field addition sequence, and static bed height. The experimental results show that when the magnetic field strength increased from 0 KA/m to 5 KA/m, the minimum fluidized gas velocity of particles increased from 4.42 cm/s to 10.32 cm/s, while the bed pressure drop first increased and then decreased. When the magnetic field strength is less than 3.4 KA/m, the microfine particles in the bed are mainly acted on by the airflow; while when the magnetic field strength is greater than 3.4 KA/m, the microfine particles are mainly dominated by the magnetic field. The magnetic field addition sequence affects the fluidization quality of microfine particles. The fluidized bed with ‘adding magnetic field first’ shows a more stable fluidization state than ‘adding magnetic field later’. Increasing of the static bed height reduces the bed expansion rate. The bed expansion rate is up to 112.5% at a static bed height of h0 = 40 mm and H = 5 KA/m. This will broaden the range of density regulation of a single magnetic particle and lay the advantage of gas-solid magnetically fluidized bed for microfine particles in the field of separation of fine coal.

DEVELOPMENT AND TESTING OF BED FORMER IMPLEMENT POWERED BY HAND TRACTORS

Soil tillage, like making raised beds, is time-consuming and labour-intensive if it is done without the help of mechanization. Therefore, this study aims to develop and test a bed former powered by a hand-tractor for upland. It was carried out in the experimental field (sandy clay loam texture) at a furrower depth of 15 cm and 20 cm with a tractor forward speed of 0.5 m/s. The bed's former design results have dimensions of length, width, and height of 1200x1000x 820 mm. The performance test results showed an increase in tillage depth resulted in increased bed height, bed width, bed width, and slip. However, field capacity decreases with increasing tillage depth. The bed former's performance was found to be satisfactory in general.

Bimetallic Fe/Al-MOF for the Adsorptive Removal of Multiple Dyes: Optimization and Modeling of Batch and Hybrid Adsorbent-river Sand Column Study

Bimetallic Metal organic framework (MOF) has garnered interest over the years with its application in various environmental remediation. In this study, Fe-Al-1,4-Benzene di-Carboxylic acid (FeAl(BDC)) MOF was synthesized, and adsorptive removal of Rhodamine B dye in batch and unique hybrid FeAl (BDC)-River sand fixed-bed column was achieved. The experimental data from the batch studies corroborated well with the Pseudo second-order (PSO) and Freundlich adsorption isotherm models. Furthermore, a fixed-bed column study was conducted to assess the effect of varying flow rate (2, 5, 8 mL/min), bed height (5, 9, 13 cm), and feed concentration (10, 20, 30 mg/L) on the adsorption performance of FeAl(BDC) in continuous mode of operation. A uniform mixture of river sand and FeAl(BDC) by weight ratio (9:1) was achieved prior to packing the column. The column study reveals that Sand-FeAl(BDC) can achieve the maximum adsorption capacity of 113.05 mg/g at a flow rate of 5 mL/min, feed concentration of 20 mg/L, and bed height of 13 cm. The experimental data of the column study were successfully fitted with BDST, Thomas, Yoon-Nelson, and Dose-response models. The fitting parameter values from the BDST model raise the scope of possible upscaling of the fixed-bed column. Hence, it is proposed that these River sand-FeAl(BDC)-based filters can be widely used in areas facing critical contamination and in poor communities with a high demand for water.

BIOSORPTION OF CU(II) IONS FROM INDUSTRIAL EFFLUENTS BY RICE HUSK: EXPERIMENT, STATISTICAL, AND ANN MODELING

Heavy metal removal from wastewater is a significant research area and recommends sustainable development. The heavy metals cause harmful health effects, increase environmental toxicity. Adsorption is a very effective method for heavy metal removal. A fixed bed for Cu(II) removal using rice hush, an agricultural waste, is reported in this paper. The study was carried out to determine the breakthrough curves with varying operating variables like influent concentration (10–30 mg/L), flow rate (10–40 ml/min), and bed height (4–10 cm) at pH 6. The variation of the process variables like influent concentration, flow rate, and bed height were investigated. The experimental data shows that adsorption capacity increases with the rise of influent concentration. The maximum value of adsorption capacity is 10.93 mg/g at a flow rate of 10 ml/min, bed height 4 cm, and influent concentration 30 mg/L. The applicability of the MLR and ANN modeling has also been successfully carried out. ANN has better predictability than MLR. The findings revealed that rice husk could be used to treat copper-containing industrial effluents.

Application of Cationic Surfactant Modified Mengkuang Leaves (Pandanus atrocapus) for the Removal of Reactive Orange 16 from Batik Wastewater: A Column Study

The feasibility of Mengkuang leaves (Pandanus atrocarpus) as a non-conventional low-cost adsorbent for the removal of an anionic dye, Reactive Orange 16 (RO16), was investigated. Among the dyes that have been commonly used in the Batik industry was reactive dye. In this study, Mengkuang leaves were chemically modified with cetyltrimethylammonium bromide (CTAB), a cationic surfactant, to improve their adsorption performance toward anionic dyes. The adsorbent’s morphological characteristics were analyzed using a scanning electron microscope (SEM). The surface of modified Mengkuang leaves seems to be irregular and uneven, with more porous structures than raw Mengkuang leaves. Adsorption of RO16 dye in fixed bed column using modified Mengkuang leaves adsorbent indicated the breakthrough time increased at higher bed height and lower flow rate. The breakthrough times for bed height of 0.5, 2, and 4 cm were at 16, 68, and 165 min, respectively. Meanwhile, breakthrough time for the flow rate of 2,5 and 7 mL.min-1 were at 327, 104, and 43 min, respectively. However, the study utilizing raw Mengkuang leaves showed no significant removal of RO16. Thus, it can be concluded that the cationic surfactant modification of Mengkuang leaves is advantageous for anionic dye removal. This anionic dye removal is significantly influenced by column parameters such as bed height and flow rate as the plotted breakthrough curves obtained from experimental data were similar to the typical breakthrough curve. When applied to the Yoon-Nelson model, the adsorption data provided the best fit with the R2 value above 0.95. The time taken for the breakthrough is very similar to model prediction values. Experiments with real batik dye wastewater showed the immense potential of modified Mengkuang leaves where total removal of real Batik wastewater was instantaneous.

Environmental Management: Pragmatic Suitability of Low Cost Activated Carbon in Lead (II)Ion Removal by Continuous Mode of Adsorption

Heavy metals such as chromium, lead, and arsenic are usually present in trace amounts in natural waters but many of them are toxic even at very low concentrations. An increasing quantity of heavy metals in our resources is currently an area of greater concern, especially since a large number of industries are discharging their metal containing effluents into freshwater without any adequate treatment. Activated carbons show a significant ability in removing heavy metal ions from an aqueous solution by adsorption, which has been examined by many researchers. Activated carbon derived from Manilkarazapota tree-wood (MZTWAC), which was found to be a suitable adsorbent for the removal of lead ions through continuous adsorption mode, was examined in this paper. A breakthrough curve has been plotted to find the effect of initial concentration and adsorbent bed height in the adsorption of lead (II)ion through MZTWAC. The breakthrough time and the saturation time increased as the initial concentration increased from 40 mg.L-1 to 60 mg.L-1. The saturation time was in the incremental mode when the bed height was increased from 5 cm to 7 cm bed thickness for 40 mg.L-1 concentration. Adams-Bohart’s model perfectly fits with this fixed-bed column in the removal of lead(II) from an aqueous solution using MZTWAC. Activated carbon derived from MZTWAC is better suited for the purpose of detoxifying metal-contaminated wastewater.

Modeling and Optimization of Gas-Solid Fluidization of Binary Mixtures using Box-Behnken Experimental Design

The influence of different factors on the fluidization of a binary mixture of red mud and aluminum was investigated. A new model was developed for predicting pressure drop through the solid bed using experimental data of other work. Statistical analysis based on response surface methodology has been used to develop correlations for bed pressure drop with three independent factors, minimum fluidization velocity (Umf), red mud to aluminum ratio (R/A), and static head (Hs). The design of experiments offers a best alternative to study the effect of factors and their response with the minimum number of experiments. The hydrodynamic characteristics of fluidization, bed pressure drop, superficial gas velocity (Umf), red mud to aluminum ratio (R/A), and initial static bed height (Hs) were modeled and optimized. ANOVA has been used to analyze the system parameters on bed pressure drop. A model of bed pressure drop was found to have a correlation coefficient of 0.98. The measured values of bed pressure drop from RSM were found to match the experimental values very well.

Influence of particles size distribution on the carbon content throughout sinter bed height

By the previous studies it was established that the character of solid fuel distribution throughout the bed height considerably effects the sintering machines productivity and the sinter quality. The purpose of the study was assessment of solid fuel distribution in the agglomerated burden throughout the height of bed at sintering machine. Sinter mix samples were taken from three sections of the bed: 150 mm - top part, 150 mm - middle part and 170 mm - bottom part at the sintering machines of NLMK. After screening the samples, particle size distribution was determined, as well as carbon content throughout the bed height and in the particles of different sizes. It was found that all solid fuel, irrespective of the size, gets balled into sinter mix granules, fine fuel (fraction -0.63 mm) was almost evenly distributed over the granules of different sizes, while coarse fuel (+3 mm) is mainly picked up by large granules. Solid fuel of -3 mm +0.63 mm fraction is mostly balled into 3-5 mm granules. Such nature of solid fuel distribution in the granules of the pelletized mix results in suboptimal distribution of fuel throughout the bed height at sintering machines No. 1, 2, despite satisfactory size segregation of the mix: it changes from low content in the top part to a higher content at the bottom of the bed. At sintering machines No. 3, 4 where there was no size segregation of the mix, fuel distribution throughout the bed height changes from optimal to non-optimal (low content in the top part). To optimize solid fuel distribution throughout the bed height with both good and poor segregation of the mix, it is necessary to reduce the content of 0-0.5 mm particles fraction in coke breeze.

Characterization of Bottom Ash Waste Adsorbent from Palm Oil Plant Boiler Burning Process to Adsorb Carbon Dioxide in a Fixed Bed Column

Palm oil bottom ash utilization from mill boilers as CO2 adsorbent has been in use for few years. This study aims to examine adsorbent characteristics and capabilities of bottom ash produced from boiler combustion in palm oil industry for CO2 adsorption before and after utilization, such as compound functional group using the Fourier Transform Infra-Red (FT-IR) spectrophotometer, adsorbent morphology through Scanning Electron Microscopy (SEM), and compound amount using Energy Dispersive X-Ray Spectroscopy (EDX). The CO2 adsorption was carried out in fixed-bed column. Process variables consist of volumetric flow rate, contact time and bed height. Results showed that SiO2 compounds in the heterogeneous form with average particle size of 1073 nm, as supported by FT-IR spectrum finding indicating SiO2 signal at wavelength of 958–954 cm–1. Additionally, EDX analysis showed Silica and Oxygen content of 11.88% and 36.90%, resulting 70% CO2 adsorption capacity of 0.350 mg/g at discharge of 5 L/min, contact time of 40 min, and bed height of 12 cm. Langmuir isotherm model was obtained with R2 of 0.998, qm of 1.588, and kL of 0.144. Meanwhile, the kinetic model followed a simple first-order prototypical with R2 of 0.952, C02 of 0.260, and k1 of 0.006.