Liquid Waste Solution Research Articles

Removal of 4-(2-pyridylazo) resorcinol and Arsenazo-III from liquid waste solutions using Penicillium oxalicum: Gamma irradiation studies

The current investigation involved the isolation of a fungal strain from liquid radioactive wastewater, which was then identified as Penicillium oxalicum and was employed to remove 4-(2-pyridylazo) Resorcinol (PAR) and Arsenazo-III (Ar-III) from liquid waste solutions. The physicochemical properties of the biosorbent fungi were analyzed using SEM and FT-IR. The biosorption effectiveness of PAR and Ar-III was investigated under several experimental settings, including pH values, adsorption times, biosorbent weight, initial dye concentrations, and reaction temperatures. The Langmuir isotherm model describes the adsorption isotherms well, with capacities of 10.88 and 11.96mgg-1 for PAR and Ar-III, respectively. The sorption of PAR and Ar-III exhibited E values of 19.84 and 17.84kJ/mol, respectively, indicating that the process is chemical adsorption. The pseudo-second-order kinetic model was determined as the most accurate representation of the biosorption kinetics. Both film diffusion and intra-particle diffusion describe the diffusion of coloring reagents through the biosorbent material. The thermodynamic analysis showed that chemical adsorption regulated the biosorption of the coloring reagent on the biosorbent material, while exothermic and spontaneous biosorption of PAR and Ar-III was observed. The extensive decolorization and easy operating circumstances demonstrated the promise of Penicillium oxalicum for the biological treatment of textile dyes.

Highly efficient and selective 99TcO4 – uptake from reprocessing low-level liquid waste using a zirconium-based metal−organic framework

ABSTRACT Efficient and selective sequestration of pertechnetate ions (99TcO4 –) from nuclear low-level waste (LLW) solution is very much desirable for the safe treatment of radioactive liquid waste. However, the separation of specific radionuclides from competitors is a huge challenge in separation science. In the nuclear fuel cycle, 99TcO4 – is one of troublesome fission products due to long half-life, large inventory in spent fuel, significant radiation hazards, and high environmental mobility of 99TcO4 – ions. Recently, the metal−organic framework (MOFs) has shown significant potentials toward 99TcO4 – removal. So far, most of the studies were reported using ReO4 – ions, an inactive surrogate of 99TcO4 – ions, and very few MOF materials are applied for real-time 99TcO4 – sequestration from nuclear waste solution in the presence of extreme conditions. Herein, we report 99TcO4 – ion removal from low-level liquid nuclear waste solution using zirconium-based metal−organic framework UIO-66-NH2. The material has exhibited fast kinetics and record selectivity toward 99TcO4 – ions, making the adsorbent highly promising.

Uranium(VI) Sorption from Liquid Waste Solution Using Functionalized Polyurethane Polymer: Kinetic and Isotherm Characterizations

Uranium(VI) Sorption from Liquid Waste Solution Using Functionalized Polyurethane Polymer: Kinetic and Isotherm Characterizations

High-efficiency separation of palladium from nitric acid solution using a silica-polymer-based adsorbent isoPentyl-BTBP/SiO2-P

A silica-polymer-based adsorbent (isoPentyl-BTBP/SiO2-P) was prepared via a vacuum impregnation method for efficient and continuous separation of palladium from complex systems. The results revealed that the distribution coefficient (Kd) value of isoPentyl-BTBP/SiO2-P toward Pd in 3 M HNO3 solution was 5226 mL/g, with a maximum adsorption capacity of 31.7 mg/g. Besides, isoPentyl-BTBP/SiO2-P exhibited a superior adsorption selectivity toward Pd to the other 14 coexisting interfering fission product ions, with the separation factor SFPd/M value over 433 in 0.1–6 M HNO3 solution. Moreover, column experiments results demonstrated that isoPentyl-BTBP/SiO2-P can efficiently separate Pd with approximately 100% recovery, from simulated high level liquid waste (HLLW) solutions with multiple competing ions. Finally, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analysis results revealed strong interactions between nitrogen-containing functional groups (C-NC) and Pd throughout the adsorption process, wherein the NO3− acting as the counterions to balance the charge. In conclusion, isoPentyl-BTBP/SiO2-P has shown promising applications for effectively separating Pd from multi-component and highly acidic environments.

Synthesis Of Mg/Al Hydrotalsite-Magnetite As CN- Ion Adsorbent On Wastewater Tapioca Industry

Cyanide compounds contained in tapioca industrial wastewater are relatively high, so it is necessary to reduce cyanide levels. This study utilizes the hydrotalcite-magnetite ability to adsorption of CN- ions. The composite formation process is carried out by mixing the magnetite phase at the stage of hydrotalcite-magnetite synthesis. The characterization of X-Ray Diffraction (XRD) shows reflection of the magnetite peak of 2θ 21.42°; 30,28°; 33.40°;35.65° and 37°. While the peak of hydrotalocites at an angle of 11.66° ; 23,33° ; 34,80° ; 60,92° ; and 62.21°. This result is supported by ir spectra on hydrotalocytes shown by O-H group at wave number 3441 cm-1, O=C-O at wave numbers 1359 cm-1, M-O and M-OH at wave numbers 964 cm-1, 797 cm-1 and 673 cm-1. Fe-O and Fe-OH absorption from magnetites at wave numbers 892 cm-1, 798 cm-1 and 629 cm-1. 0.4 grams of hydrotalcite-magnetite at 30 minutes of stirring absorbed 0.0490 mg/L of cyanide from tapioca liquid waste solution. The value of adsorption capacity is 0.022 mg/g and the adsorption efficiency is 87.96%. The hydrotalcite-magnetite adsorption method is superior to aerob and anaerobic methods using bacteria in the tapioca industry.

Sorption of some radionuclides from liquid waste solutions using anionic clay hydrotalcite sorbent

129I and 79Se are potentially important anionic radionuclides in safety assessments due to their high mobility, radiotoxicity, and long half life's (1.7 × 107 and 3.27 × 105 years, respectively). This study is interested in the sorption of 131I and 75Se radionuclides onto magnesium iron hydrotalcite (Mg/Fe HTlc). Mg/Fe HTlc was prepared by co-precipitation technique and characterized using different analytical tools such as FT-IR, XRD, XRF, TGA & DTA, SEM, and BET. Results obtained from this study showed that the adsorption process was a very fast equilibrium time (20 min). The distribution coefficient values as a function of pH have high separation factors for 131I at all different pHs. Reaction kinetic obeys the pseudo-second-order model. Maximum sorption capacity for 131I and 75Se has the values 21.45, and 9.25 mg/g respectively. Sorption isotherms are more relevant to a Langmuir isotherm. The % removal of 131I is decreased by increasing the concentration of competing species. The investigation evidenced that the prepared sorbent is suitable for the removal of 131I and 75Se from radioactive waste and could be considered potential material for purification of effluent polluted with these radionuclides.

Extraction chromatography based separation of zirconium(IV) from simulated high-level liquid waste using N,N-di-octyl-2-hydroxyacetamide impregnated amberlite XAD-7 resin

Selective separation of zirconium(IV), from the simulated high-level liquid waste solution containing uranium(VI) and trivalent lanthanides, during reprocessing of fast reactor metal fuel was studied by extraction chromatography using N,N-di-octyl-2-hydroxyacetamide (DOHyA) impregnated on to Amberlite XAD-7 resin. The extraction behavior of Zr(IV), Nd(III) and U(VI) with varying concentrations of nitric acid was explored using a solvent impregnated resin with different compositions of DOHyA in XAD-7 [10, 20, 30, 40 and 50 (w/w) %]. The resin exhibited faster kinetics with more than 99 % recovery of Zr(IV) and with an apparent Langmuir adsorption capacity of ∼54 mg.g−1of Zr(IV) on to the resin phase. Quantitative (> 99%) and selective extraction of Zr(IV) with minimum loading of other trivalents and uranium was observed during column chromatography. Results of the study showed that Zr(IV) can be selectively separated in presence of trivalent lanthanides and U(VI).

Extraction and aggregation behaviour of Zr(IV) in diglycolamide solvents during the treatment of high-level liquid waste solution arising from metallic fuel reprocessing

Zirconium was identified as a troublesome fission product interfering with the separation of trivalent actinides from high-level liquid waste (HLLW) solution. Since zirconium was used as a fuel component in metallic fuels, the amount of Zr(IV) present in HLLW arising from reprocessing of metallic fuel was nearly ten times higher than the conventional HLLW solutions. In the present study, the diglycolamide extractants proposed for the separation of trivalent actinides from HLLW were employed for the extraction of metal ions from nitric acid medium and fast reactor simulated high level liquid waste (FR-SHLLW) having the Zr(IV) concentrations varied from 0.006 M to 0.09 M. Dynamic light scattering study was performed on the organic phase obtained after extraction of zirconium to analyze the aggregation of extractants. The solvent system consisting of 0.1 M TODGA (N,N,N’,N’-tetraoctyldiglycolamide) along with 0.25 M HDEHP (bis(-2-ethylhexyl)phosphoric acid) in n-dodecane showed minimal aggregation tendency and higher loading capacity of Zr(IV) and was selected for further extraction of trivalent metal ions from FR-SHLLW. To minimize the extraction of Zr(IV) in organic phase, the effect of aqueous soluble complexing agent namely trans-1,2-diaminocyclo-hexane-N,N,N’N’-tetraaceticacid (CyDTA) was also studied during the extraction of trivalent lanthanides.

Selective removal of Zr(IV) from simulated High-Level liquid waste of metallic fuel reprocessing using hydroxyacetamide Extractant: Insights from solvent extraction and density functional theory computations

A liquid-liquid extraction method for the separation of Zr(IV) from simulated high-level liquid waste (SHLLW) solutions using N,N-di-octyl-2-hydroxyacetamide (DOHyA) was studied. The method was found to be applicable for the recovery of Zr(IV) from conventional SHLLW solutions as well as the SHLLW solutions from metallic fuel reprocessing streams containing Zr(IV) up to 8 g/L. DOHyA showed quantitative extraction of Zr(IV) from all the simulated waste solutions, along with co-extraction of other fission products and Am(III). Excluding Zr(IV) and Mo(VI), all the other co-extracted metal ions were efficiently scrubbed from the loaded DOHyA solvent using 0.5 M or 1 M nitric acid. The selective stripping of Zr(IV) that remained in the solvent phase was subsequently accomplished using 0.2 M oxalic acid solution. The complexation behaviour of Zr(IV) with DOHyA was investigated using Density Functional Theory (DFT) calculations, which divulged the geometry and stability of Zr-DOHyA-HNO3 and Zr(C2O4)2 complexes formed under the extraction and stripping conditions. With the aid of quantum theory of atoms in molecules, natural bond orbital and non-covalent interaction analyses, the rationale behind the selective removal of Zr(IV) from SHLLW using DOHyA extractant was clearly unravelled.

Phosphate controls uranium release from acidic waste-weathered Hanford sediments

Mineral dissolution and secondary phase precipitation may control the fate of inorganic contaminants introduced to soils and sediments during liquid waste discharges. When the solutions are aggressive enough to induce transformation of native minerals, incorporated contaminants may be released during dissolution due to percolation of meteoric waters. This study evaluated the release of uranium (U) from Hanford sediments that had been previously reacted for 180 or 365 days with liquid waste solutions containing U with and without 3 mM dissolved phosphate at pH 2 and 3. Flow-through column experiments were conducted under continuous saturated flow with a simulated background porewater (BPW; pH ~7) for 22 d. Up to 5% of the total U was released from the sediments reacted under PO4-free conditions, attributable to the dissolution of becquerelite and boltwoodite formed during weathering. Contrastingly, negligible U was released from PO4-reacted sediments, where meta-ankoleite was identified as the main U-mineral phase. Linear combination fits of U LIII-edge EXAFS spectra of sediments before and after BPW leaching and thermodynamic calculations suggest that the formed becquerelite and meta-ankoleite transformed into schoepite and a phosphuranylite-type phase, respectively. These results demonstrate the stabilization of U as recalcitrant uranyl minerals formed in sediments and highlight the key role of PO4 in U release at contaminated sites.

Decrease in the activity of irradiated graphite and liquid radioactive waste

Nowadays, the problem of nuclear waste deactivation is very urgent. The method proposed consists of exposing the aqueous solution of radionuclide to powerful nanosecond electromagnetic pulses by placing the treated solution between two electrodes connected to the outlets of the generator. Single-pole current pulses with a length of 1 ns, an amplitude of more than 5 kV, and a repetition frequency of 1 kHz are used. Such pulses can be obtained from the generator units with an amplitude of 5 kV to 15 kV. They have a pulse capacity of 1 to 4 MW, and the mains capacity is below 50 W. The pulse action leads to radiolysis of water and accelerated decay of radionuclides. As a result of radiolysis, hydrated electrons, hydrogen atoms, and various radicals are formed that causes precipitation of radionuclides, such as 137Cs and 90Sr. The description of several experiments and results of experimental investigations of the influence of powerful nanosecond electromagnetic pulses on the properties of water solutions with radioactive nuclides 137Cs and 90Sr and on items of irradiated graphite is presented. Under the influence of pulses on real liquid waste and aqueous solutions, radioactive nuclides in water are reduced by 5 to 50 times during 15 minutes. The effect described is preserved for 20 days. The reduction of beta activity twice during 25 min is observed in big blocks of the irradiated graphite. Flow-through unit for processing of liquid waste is developed, tested, and patented (RU 2726145. MPK G21F 9/28, July 7, 2020). This technology can be used to treat emergency solutions with tritium at Fukushima NPP. of the irradiated graphite.

Nd(III) hypersensitive peak as an optical absorption probe for determining nitric acid in aqueous solution: An application to aqueous raffinate solutions in nuclear reprocessing

A new method using Nd(III) absorption peak as a probe is described for the measurement of nitric acid concentration in aqueous solution. The hypersensitive peak of Nd(III) at 575.1 nm shows a substantial enhancement in the absorbance in comparison to other absorption peaks with increasing nitric acid concentration. The integrated area and absorbance of this hypersensitive peak show a linear dependency over a large dynamic range of 0.5–15.5 M of nitric acid. A methodology for the correction of spectral interference to the probing absorption peak of Nd(III) is also reported. The method is applied for the measurement of nitric acid in synthetic high level liquid waste solution and shown to be comparable to that obtained by titrimetric method. The present method can be easily adopted for the measurement of nitric acid concentration in aqueous raffinate solutions of nuclear reprocessing streams.

Uranium removal using composite membranes incorporated with chitosan grafted phenylenediamine from liquid waste solution

New composite membranes of polysulfone (PSu) and cellulose acetate (CA) incorporated with pre-synthesized chitosan grafted p-phenylenediamine (Ch-g-PDA) were prepared and tested for uranium adsorption. The new composite membrane offers easily handling, low cost and reasonable efficiency adsorptive candidate. The prepared membranes were characterized with FTIR, XRD, SEM and EDX. Application of the new membranes in uranium removal from its waste was investigated. Optimization the adsorption variables as metal ion concentration, pH and contact time were performed followed with adsorption isotherm and kinetics models in order to estimate the adsorption mechanism and rate. The Langmuir model can define the isotherm adsorption with a maximum capacity of 44 mg g−1 and 39 mg g−1 for synthesized PSu/C-g-PDA and CA/C-g-PDA, respectively, within short time. Uranium adsorption experimental data demonstrated that both adsorbents were well fitting with Langmuir isotherm and pseudo-second order kinetics model. The reusability of the membrane in six adsorption desorption cycles, resulted in adsorption efficiency of 85.8, and 83.8 % for for synthesized PSu/C-g-PDA and CA/C-g-PDA, respectively, of the initial values which indicate the stability and efficiency of the composite membranes in U removal from waste solution.

Bioremediasi Limbah Cair Industri Tahu Menggunakan Larutan EM4 secara Anaerob-Aerob

This research using a bioremediation treatment process with anaerobic-aerobic system by mixing tofu liquid waste and EM4 solution into the reactor. The variation of EM4 solution that will be used in this research is 1/20 of concentration with 1/10 of concentration and detention time. This research was conducted for 8 days. The result showed that EM4 solution was able to reduce BOD, COD, and TSS by usinng variations in concentration and detention time. The most significant decrease in BOD, COD, adn TSS levels occured on the 8 day. BOD levels for the first reactor at a concentration of 1/10 with a removal efficiency of 48,98% and a second reactor with removal efficiency of 48,98%. For the 1/20 concentration the removal efficiency was 37,33% and in second reactor the removal efficiency was 37,34%. COD levels for the first reactor at a concentration of 1/10 with a removal efficiency of 61,82% and a second reacotor with removal efficiency of 62,10%. For the 1/20 concentration the removal efficiency was 30,39% an in second reactor the removal efficiency was 34,98%. TSS levels for the first reactor at a concentration 1/20 with removal efficiency of 41,17% and in the second reactor the removal efficiency of 43,59%. At 1/20 concentration the removal efficiency of TSS levels was 1,02% in the first reactor and in the second reactor the removal efficiancy was 5,10%. Bioremediation using EM4 solution can be used to reduce levels of BOD, COD, and TSS of tofu liquid waste according to the applicable quality standards

New adsorptive composite membrane from recycled acrylic fibers and Sargassum dentifolium marine algae for uranium and thorium removal from liquid waste solution

Novel adsorption Algal polymer composite membrane composed of acrylic fiber wastes and grinded marine algae; Sargassum dentifolium was newly prepared using inversion precipitation technique. The adsorption of uranium and thorium from their waste solution was evaluated. The results indicated that the sorption capacities for U and Th were 62 and 59.4 (mg g−1), respectively, within short time. Adsorption experimental data demonstrated that both metal ions were well fitting with Langmuir isotherm and pseudo-second order kinetics model. The reusability of the composite membrane indicates the stability and efficiency of it in U and Th removal from waste solution.

Development of Palm Oil-Based Synergist Liquid Membrane Formulation for Silver Recovery from Aqueous Solution

In this work, the palm oil-based synergist formulation containing a mixture of carriers for liquid membrane application of silver recovery from aqueous solution was studied. Several types of acidic carrier mixtures were investigated via liquid-liquid extraction procedure to increase the extraction performance. The results indicated that palm cooking is a promising vegetable oil-based green diluent in the formulation. A carrier mixture of 0.2 mM Cyanex 302 and 0.3 mM Cyanex 272 demonstrated synergism during the extraction process. It was found that more than 98% of silver ions from a very dilute solution was effectively extracted with a synergistic coefficient of 62.7. According to the individual and carrier mixture results, it can be deduced that Cyanex 272 and Cyanex 302 served as a carrier and synergist, respectively. Therefore, the developed liquid membrane formulation showed great prospect in silver recovery from the liquid waste solution.

Complexation and bonding studies on [Ru(NO)(H2O)5]3+ with nitrate ions by using density functional theory calculation.

Complexation reactions of ruthenium–nitrosyl complexes in HNO3 solution were investigated by density functional theory (DFT) calculations in order to predict the stability of Ru species in high-level radioactive liquid waste (HLLW) solution. The equilibrium structure of [Ru(NO)(NO3)3(H2O)2] obtained by DFT calculations reproduced the experimental Ru–ligand bond lengths and IR frequencies reported previously. Comparison of the Gibbs energies among the geometrical isomers for [Ru(NO)(NO3)x(H2O)5−x](3−x)+/− revealed that the complexation reactions of the ruthenium–nitrosyl complexes with NO3− proceed via the NO3− coordination to the equatorial plane toward the Ru–NO axis. We also estimated Gibbs energy differences on the stepwise complexation reactions to succeed in reproducing the fraction of Ru–NO species in 6 M HNO3 solution, such as in HLLW, by considering the association energy between the Ru–NO species and the substituting ligands. Electron density analyses of the complexes indicated that the strength of the Ru–ligand coordination bonds depends on the stability of the Ru species and the Ru complex without NO3− at the axial position is more stable than that with NO3−, which might be attributed to the difference in the trans influence between H2O and NO3−. Finally, we demonstrated the complexation kinetics in the reactions x = 1 → x = 2. The present study is expected to enable us to model the precise complexation reactions of platinum-group metals in HNO3 solution.

Phenol recovery using continuous emulsion liquid membrane (CELM) process

Liquid membrane technology in batch operation is not quite feasible at industrial level. Hence, a continuous emulsion liquid membrane (CELM) process was conducted in this study to extract phenol from liquid waste solution. An extractor of 1.5 L equipped with baffles was used for well mixed during the extraction process. ELM formulation consists of a mixture of kerosene and palm oil, span 80 and sodium hydroxide as a diluent, surfactant, and strippant, respectively. Meanwhile, 300 ppm of simulated phenol wastewater was used as a feed phase. ELM was found to be stable at 3% (w/v) of Span 80, 5 min of emulsification time and 1300 rpm of emulsification speed. Then, parameters influencing recovery were optimized using the response surface methodology including rotational speed (400 to 800 rpm), treat ratio (1:3 to 1:10) and retention time (2 to 6 min). Increasing rotational speed, treat ratio, and retention time up to 527 rpm, 1:4 and 4 min, respectively offer high recovery efficiency of phenol when achieving about seven times enrichment in the internal phase (2100 ppm).

The role of graphene oxide anchored 1-amino-2-naphthol-4-sulphonic acid on the adsorption of uranyl ions from aqueous solution: kinetic and thermodynamic features

ABSTRACTGraphene oxide-1-amino-2-naphthol-4-sulphonic acid (GOANS) adsorbent synthesised successfully from a natural source (Cattle bones) for the U(VI) ions removal from liquid waste solutions. The synthesised adsorbent characterised via Fourier transform infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) Surface Area Analysis, Energy-dispersive X-ray spectroscopy(EDX) pattern and scanning electron microscopy (SEM). Various experimental parameters (time, adsorbent weight, initial uranium concentration and temperature) investigated and the results reveal that a higher uptake capacity of 311.5 mg/g achieved at pH 4 within 60 minutes. The obtained findings fitted well with thermodynamic, isothermal (Langmuir and Freundlich model) and pseudo second order kinetics. The negative sign of specified the spontaneity of adsorption process in the thermodynamic study, (endothermic) and positive sign indicate high randomness after adsorption.

Autoclaving Contaminated Liquids

In many research and diagnostic facilities, liters of biologically contaminated liquid waste are produced on a daily basis and need to be safely disposed of. The gold standard is steam sterilization, namely, in most cases autoclaving for 20 minutes at 121°C. Here we demonstrate the importance of the following parameters when autoclaving liquid waste solutions in a laboratory setting: (1) size of the receptacle for the reference probe, (2) material of the vessel containing the liquid to be autoclaved, and (3) volume of the liquid in the receptacle. If not appropriately controlled, the temperature required to inactivate the liquid might never be reached at all, thus representing a biohazard that should not be underestimated. Our results demonstrate that it is critical to use identical receptacles and liquid volumes for the temperature reference probe and for the liquid to be autoclaved.