Step In Recycling Research Articles

An Attention-Based CNN-LSTM Method for Effluent Wastewater Quality Prediction

Wastewater treatment is a pivotal step in water resource recycling. Predicting effluent wastewater quality can help wastewater treatment plants (WWTPs) establish efficient operations so as to save resources. We propose CNN-LSTM-Attention (CLATT), an attention-based effluent wastewater quality prediction model, which uses a convolutional neural network (CNN) as an encoder and a long short-term memory network (LSTM) as a decoder. An attention mechanism is used to aggregate the information at adjacent sampling times. A sliding window method is proposed to solve the problem of the prediction performance of the model decreasing with time. We conducted the experiment using data collected from a WWTP in Fujian, China. Our results show that the accuracy of prediction is improved, with MSE decreasing by 0.25, MAPE decreasing by 5% and LER decreasing by 7%, after using the sliding window method. Compared with other methods, CLATT achieves the fastest prediction speed among all the methods based on LSTM and the most accurate prediction performance, with MSE increasing up to 0.92, MAPE up to 0.08 and LER up to 0.11. Furthermore, we performed an ablation study on the proposed method to validate the rationality of the major part of the model, and the results show that the LSTM significantly improves the predictive performance of the model, and the CNN and the attention mechanism also improve the accuracy of the prediction.

Complete recycling of valuable metals from electroplating sludge: Green and selective recovery of chromium

The recovery of chromium (III) is a key step for complete recycling of heavy metals from electroplating sludge. Therefore, thermodynamic equilibrium diagrams of Me-PO43--H2O[Me: Cr (III), Zn (II), Cu (II), Fe (II), Fe (III), Ni (II)] systems at 298 K have been established, the thermodynamic analysis for the precipitation of chromium (III) using phosphates and the conversion of CrPO4 to Cr(OH)3 using caustic soda were conducted. The results showed that phosphate seemed preferentially combined with Cr (III) rather than other metal cations in order of Cr (III) > Fe (III) > Fe (II) > Zn (II) at the pH range of 1.0 ∼ 5.0. The verification experiment results indicated that about 94.1% Cr (III), 5.51 %Fe (II), and 0.33% Zn (II) reached were precipitated by adding 110% theoretical amount of Na3PO4·12H2O at equilibrium pH equal to 2.0. As consistent with the thermodynamic analysis, alkali conversion of CrPO4 with NaOH achieved a leaching efficiencies of Cr (III) and phosphorus were 5.1% and 90.6%, which realized phosphate recycling and the recovery of leached Cr (III). 99.7% Zn was deeply separated and recovered from Fe (II/III) by D2EHPA by two stages of counter current extraction with an O/A ratio of 1:2, 5 min stirring at 20 °C. And the optimal conditions for Zn stripping were considered as mixing 1 mol/L H2SO4 and loaded D2EHPA with O/A ratio of 5:1 at room temperature for 5 min. The proposed process shows a promising industrial application in view of its low cost, complete recycling, and wide adaptability. SynopsisElectroplating sludge will cause serious pollution to the environment if not properly treated. This study reports a new treatment method of electroplating sludge to achieve comprehensive recovery of all valuable metals. Compared with traditional process, this process exhibits a promising industrial application due to its no emissions, lower cost, complete reagent cycle, purer product, higher quality, broader adaptability, and greener production.

Characterization of cool flame products during the low temperature oxidation of n-pentylbenzene

Radical chain recycling reactions represent a general topic in the chemistry of combustion, atmosphere, polymerization and so on. The nature and amount of OH radicals that generated by hydroperoxides during the oxidation of alkanes have been proven to drive the overall reactivity by enhancing the chain recycling steps. While low temperature oxidation kinetics of alkanes have been widely investigated, the comprehensive intermediates distribution during the low temperature oxidation of n-alkylbenzenes remains unexplored. This work selects n-pentylbenzene as a simple representative to investigate the low temperature oxidation kinetics of n-alkylbenzenes, especially intermediates and reactions that control the reactivity. The experiments were performed with a jet-stirred reactor coupled with the synchrotron vacuum ultraviolet radiation photoionization mass spectrometry (SVUV-PIMS). Around 70 intermediates, including phenyl hydroperoxides and highly oxygenated molecules (HOMs) were detected. By combining theoretical calculations and kinetic analysis, potential compositions and structures of key intermediates were identified and categorized into groups by their characteristic molecular formulae and chemical functionalities, such as C11H16On, C11H14On, C11H10On. Fingerprint hydroperoxides, including phenyl alkyl hydroperoxides, ketohydroperoxides, olefinic hydroperoxides, ketodihydroperoxides, were revealed to be formed from the characteristic first, second and third O2 addition and sequential reactions. These hydroperoxides play a dominant role in driving the low temperature oxidation reactivity by generating active OH radicals. The present experimental evidence, including the negative temperature coefficient behavior of n-alkylbenzenes as well as featured HOMs from the third O2 addition, extend the conceptual reaction schemes proposed in alkanes towards the oxidation of n-alkylbenzenes.

Effect of Mechanical Recycling on the Mechanical Properties of PLA-Based Natural Fiber-Reinforced Composites

The present study investigates the feasibility of utilizing polylactic acid (PLA) and PLA-based natural fiber-reinforced composites (NFRCs) in mechanical recycling. A conical twin screw extrusion (CTSE) process was utilized to recycle PLA and PLA-based NFRCs consisting of 90 wt.% PLA and a 10 wt.% proportion of either basalt fibers (BFs) or halloysite nanotubes (HNTs) for up to six recycling steps. The recycled material was then injection molded to produce standard test specimens for impact strength and tensile property analysis. The mechanical recycling of virgin PLA led to significant discoloration of the polymer, indicating degradation during the thermal processing of the polymer due to the formation of chromatophores in the structure. Differential scanning calorimetry (DSC) analysis revealed an increase in glass transition temperature (Tg) with respect to increased recycling steps, indicating an increased content of crystallinity in the PLA. Impact strength testing showed no significant detrimental effects on the NFRCs’ impact strength up to six recycling steps. Tensile testing of PLA/HNT NFRCs likewise did not show major decreases in values when tested. However, PLA/BF NFRCs exhibited a significant decrease in tensile properties after three recycling steps, likely due to a reduction in fiber length beyond the critical fiber length. Scanning electron microscopy (SEM) of the fracture surface of impact specimens revealed a decrease in fiber length with respect to increased recycling steps, as well as poor interfacial adhesion between BF and PLA. This study presents a promising initial view into the mechanical recyclability of PLA-based composites.

Abstract 5025: Reduced level of protein kinase C iota renders human glioblastoma less invasive and induces apoptosis via modulating Tak1/NF-κB pathway

Abstract Glioblastoma (GBM) is characterized by poor therapeutic response and overall survival. It is the most aggressive form of primary brain tumor with a tendency to invade surrounding healthy brain tissues, rendering them largely incurable. In this study, small-interference RNA was used to knock down the expression of protein kinase C PKC-ι. The reduced PKC-ι expression impaired the phosphorylation of LIM kinase 1/2 (LIMK), which is a critical step in cofilin recycling and actin polymerization. Additionally, there was a down-regulation of matrix metalloprotease-9 expression in LN-229 and U87G cells, which coincided with decreased invasion. Therefore, PKC-ι regulates both cytoskeleton rearrangement and cell adhesion, which contributed to cell migration. Silencing of PKC-ι also dampened Transforming growth factor-β (TGF-β)-activated kinase 1 (Tak1) level. TAK1 is an essential component in genotoxic stresses-induced NF-κB-activation and mitogen-activated protein kinase (MAPK)-pathways in GBM. TAK1, when activated, forms a complex with TAB1-3 (Tak1 binding proteins). Our data reveal, reduced Tak1 level after silencing PKC-ι interferes with complex formation and reduces NF-κB-activation. Diminished PKC-ι level also reduces activation of Tak1/JNK axis. This deactivation exerts an anti-oncogenic effect on glioblastoma via suppression of Akt1, c-Myc, and STAT3. This implies PKC-ι may have a crucial role in the activation of Tak1. Reduced migration and invasion in glioblastoma cells upon inhibition of PKC-ι was further confirmed by Scratch assay and Boyden assay. These results indicate that PKC-ι is involved in the control of glioblastoma cell migration and invasion. PKC-ι is a central component of multiple converging and bifurcating pathways and is a potential therapeutic target against GBM survival and infiltration. Citation Format: Khandker Mohammad Khalid, Wishrawana S. Ratnayake, Avijit Dey, Nuzhat N. Oishee, Mahfuza Marzan, Mildred Acevedo-Duncan. Reduced level of protein kinase C iota renders human glioblastoma less invasive and induces apoptosis via modulating Tak1/NF-κB pathway. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5025.

Identification of overlapping plastic sheets using short-wavelength infrared hyperspectral imaging.

Plastic identification is a fundamental step in material and chemical recycling. Overlap between plastics is a common limitation of existing identification methods, and it is necessary for plastic waste to be shredded and spread over an area to avoid overlapping between flakes. However, this process decreases sorting efficiency and also increases the risk of misidentification. This study specifically focuses on plastic sheets and aims to develop an efficient identification method for overlapping plastic sheets, by using short-wavelength infrared hyperspectral imaging. The method is based on the Lambert-Beer law and is simple to implement. We consider a practical situation with a reflection-based measurement system and demonstrate the identification performance of the proposed method. The tolerance of the proposed method against error sources of measurement is also discussed.

A method for using the residual energy in waste Li-ion batteries by regulating potential with the aid of overvoltage response

The value of considerable residual energy in waste Li-ion batteries (WLIBs) is always neglected. At present, "this energy" is always wasted during the discharge process of WLIBs. However, if this energy could be reused, it would not only save a lot of energy but also avoid the discharge step of recycling of WLIBs. Unfortunately, the instability of WLIBs potential is a challenge to efficient utilization of this residual energy. Here, we propose a method that could regulate the cathode potential and current of the battery by simply adjusting the solution pH to utilize 35.08%, 88.4%, and 84.7% of the residual energy for removing heavy metal ions from wastewater, removing Cr (VI) from wastewater, and recovering copper from the solution, respectively. By taking advantage of the high internal resistance R of WLIBs and the sudden change of battery current I caused by iron passivation on the positive electrode of the battery, this method could induce the response of overvoltage η (η = IR) inside the battery at different pH levels to regulate the cathode potentialµ of the battery to the three intervals. The potential ranges of the battery cathode corresponding to pH < 3.4, pH ≈ 3.4, and pH > 4 were µ > -0.47V, -0.47V < µ < -0.82V, and µ < -0.82V, respectively. This study provides a promising way and theoretical basis for the development of technologies for reusing residual energy in WLIBs.

Zeolite 4A activates peroxymonosulfate toward the production of singlet oxygen for the selective degradation of organic pollutants

Zeolite 4A (Z4A), synthesized from natural kaolin by an easy and low-cost method, was used to activate inorganic peroxides for degrading organic pollutants in water. Z4A had a high catalytic capability for the activation of peroxymonosulfate (PMS) but a low effect on peroxydisulfate (PDS) or hydrogen peroxide (H2O2). The non-radical pathway dominated the degradation of the pollutants, due to acid-base interactions of PMS with Z4A, as indicated by the characterization of the fresh and used zeolite. Additionally, in the Z4A/PMS system, synergistic effects in the elimination of two representative contaminants (ciprofloxacin “CIP” and methyl orange “MO”) were observed. The Z4A/PMS system induced the opening of the piperazyl ring of CIP, and the cleavage of the azo-benzene bond of MO. These primary transformations occurred in electron-rich groups, as supported by theoretical analyses on atomic charge developed herein. Interestingly, Z4A showed high activating/degrading capability even after three reuse cycles without the involvement of the typical recycling steps (filtration, washing, and drying) for a solid recovery. Furthermore, when compared with a sonochemical process, the Z4A/PMS system was highly efficient and more selective for the degradation of both CIP in synthetic fresh urine and MO in simulated textile wastewater. This study offers relevant findings on the PMS activation toward the non-radical pathway using the zeolite 4A, which represents an interesting alternative to those materials composed of transition metals or carbonaceous structures, to treat organic pollutants in aqueous samples in a selective way.

Circular Recycling Strategies for LFP Batteries: A Review Focusing on Hydrometallurgy Sustainable Processing

The exponential growth of electric and hybrid vehicles in the last five years forecasts a waste problem when their batteries achieve end-of-life. Li-ion batteries for vehicles have been assembled using materials from natural resources (as Li, Fe, Al, Cu Co, Mn and P). Among them, LiFePO4 cathode materials have demonstrated advantages such as charge–discharge cycles, thermal stability, surface area and raw materials availability (against Ni and Co systems). Due to the performance, LFP batteries stand out in heavy duty fleet, achieving 90% of new energy buses in China. To achieve the circular economy, the recycling of LFP batteries may be carried out by pyrometallurgy (thermal processing), hydrometallurgy (aqueous processing) or both in combination. Comparatively, hydrometallurgical processing is more advantageous due to its low energy consumption and CO2 emissions. In addition, Li may be recovered in a high-pure grade. This work is a literature review of the current alternatives for the recycling of LFP batteries by hydrometallurgy, comparing designed processes in the literature and indicating solutions towards a circular economy. The major recycling steps of hydrometallurgy routes such as pre-treatments, leaching and purification steps will be gathered and discussed in terms of efficiency and environmental impact.

Three kinetically distinct but compatible routes of Rho-dependent termination uncovered by single-molecule transcription imaging.

When gene transcription for RNA synthesis terminates in a factor-dependent manner, Rho is a general termination factor in bacteria, but its mechanism has been elusive in many aspects. Various models have been proposed for the pre-terminational interaction of Rho with RNA polymerase (RNAP), for the terminational release of RNA transcript, and for the post-terminational outcome. We developed several single-molecule fluorescence assays in order to monitor those three steps of termination mediated by Escherichia coli Rho. We find that the different mechanisms previously proposed for each step co-exist compatibly together in any single terminator but three kinetically distinct routes take place with each terminator. Rho mostly binds nascent RNA first at a rut site, translocates on RNA and catches up with the paused RNAP at the termination site. The fastest route is that this catch-up Rho first mediates RNA shearing for RNA-only release and consequently one-dimensional recycling of the DNA-bound RNAP. The catch-up Rho later mediates RNAP displacement in the next but the most frequent route to decompose RNAP·DNA·RNA complexes in a step for three-dimensional recycling of the dissociated RNAP. Contrastingly, a minor fraction of Rho pre-binds RNAP prior to the terminational pausing site and stands by for an incipient RNA rut site. This stand-by Rho lastly mediates only RNAP displacement for the decomposing outcome in the slowest route, despite interacting with RNAP earlier than the catch-up Rho. Furthermore, we uncover that transcriptional pause extension benefits only the stand-by Rho's termination, and the essential pause does not need to be long for the catch-up Rho's terminations The riboswitch-associated termination is controlled mainly by modulation of the stand-by. Thus, the three compatible routes of Rho-dependent termination not only operate on distinct timescales but also play different regulatory roles.

Siemens Reloaded: Chloride-Assisted Selective Hydrodechlorination of SiCl4 to HSiCl3.

Trichlorosilane is the key intermediate for the large-scale production of polycrystalline silicon in the Siemens and Union Carbide processes. Both processes, however, are highly inefficient, and over two thirds of the trichlorosilane employed is converted to unwanted silicon tetrachloride accumulating in millions of tons per year on a global scale. In this combined experimental and theoretical study we report an energetically and environmentally benign synthetic protocol for the highly selective conversion of SiCl4 to HSiCl3 using organohydridosilanes as recyclable hydrogen transfer reagents in combination with onium chlorides as efficient catalysts. We put the same protocol to further use demonstrating the quantitative conversion of higher oligosilane residues, which form as another unwanted and potentially hazardous byproduct of Siemens processes, to HSiCl3 in a low-temperature recycling step.

High separation efficiency of ternary cathode materials from spent lithium-ion batteries by ternary molten Li-salt method

Recycling of spent lithium-ion batteries is an urgent task in view of the resource shortage and environmental concerns. Pretreatment as the first step in recycling of spent lithium-ion batteries has become urgent issue for efficient separation of spent cathode materials from aluminum foil. Herein, a facile ternary molten salts approach is presented for efficient separation of cathode material and aluminum foil synchronous implementation of regeneration of spent cathode material. The separation efficiency reaches 99.98% at molar ratio of LiNO3: LiOH·H2O: Li2CO3(LNOC) of 3:2:0.5 with mass ratio of spent cathode pieces to the ternary molten salts of 1:2 holding at 300 °C for 15 min. The regenerated materials show discharging capacity of 122.2 mAhg−1 at 1C with retention rate of 99.97% after 100 cycles. The ternary molten salts are also made available for separation of other spent cathode materials with achieving high separation efficiency.

SART3 associates with a post-splicing complex.

SART3 is a multifunctional protein that acts in several steps of gene expression, including assembly and recycling of the spliceosomal U4/U6 small nuclear ribonucleoprotein particle (snRNP). In this work, we provide evidence that SART3 associates via its N-terminal HAT domain with the 12S U2 snRNP. Further analysis showed that SART3 associates with the post-splicing complex containing U2 and U5 snRNP components. In addition, we observed an interaction between SART3 and the RNA helicase DHX15, which disassembles post-splicing complexes. Based on our data, we propose a model that SART3 associates via its N-terminal HAT domain with the post-splicing complex, where it interacts with U6 snRNA to protect it and to initiate U6 snRNA recycling before a next round of splicing.

Investigation of deinking efficiencies of trigromi laserjet printed papers depending on the number of recycling

PurposeThis study aims to determine the ink removal efficiency of papers with different recycling numbers and to examine some electrophotographic printing properties.Design/methodology/approachThe base papers prepared according to the INGEDE 11p standard are subjected to six recycling stages (RS) under equal conditions. The physical-optical properties of the papers obtained at the end of each RS are measured and CMYK (cyan, magenta, yellow, key) color measurement scales are printed on each paper with electrophotographic printing. Color measurements of the printed papers are measured using the X-Rite eXact spectrophotometer, adhering to the ISO 13655:2017 standard. According to the measurement results of the optical properties, the ink removal efficiency of each recycling step is determined as a percentage (%) using some formulas.FindingsAs general, according to DEMLab and IERIC data, it is determined that the ink removal efficiency increased as the recycling repetition increased. In DEMf factor values, the highest deinking efficiency is obtained after the fourth RS. There is no significant difference between the printing properties of the samples.Originality/valueIt has been a matter of curiosity that papers lose their properties after how many RS. Many studies have been carried out on this subject and it has been presented by experimental methods that the printability properties of papers increase or decrease after which RS. This study can be a pioneer for future studies.

Diverted from Landfill: Reuse of Single-Use Plastic Packaging Waste

Low-density polyethylene (LDPE) based packaging films mostly end up in landfill after single-use as they are not commonly recycled due to their flexible nature, low strength and low cost. Additionally, the necessity to separate and sort different plastic waste streams is the most costly step in plastics recycling, and is a major barrier to increasing recycling rates. This cost can be reduced through using waste mixed plastics (wMP) as a raw material. This research investigates the properties of PE-based wMP coming from film packaging wastes that constitutes different grades of PE with traces of polypropylene (PP). Their properties are compared with segregated individual recycled polyolefins and virgin LDPE. The plastic plaques are produced directly from the wMP shreds as well as after extruding the wMP shreds into a more uniform material. The effect of different material forms and processing conditions on the mechanical properties are investigated. The results of the investigation show that measured properties of the wMP fall well within the range of properties of various grades of virgin polyethylene, indicating the maximum possible variations between different batches. Addition of an intermediate processing step of extrusion before compression moulding is found to have no effect on the tensile properties but results in a noticeably different failure behaviour. The wMP does not show any thermal degradation during processing that was confirmed by thermogravimetric analysis. The results give a scientific insight into the adoption of wMP in real world products that can divert them from landfill creating a more circular economy.

Influence of Stabilization Additive on Rheological, Thermal and Mechanical Properties of Recycled Polypropylene.

To decrease the amount of plastic waste, the use of recycling techniques become a necessity. However, numerous recycling cycles result in the mechanical, thermal, and chemical degradation of the polymer, which leads to an inefficient use of recycled polymers for the production of plastic products. In this study, the effects of recycling and the improvement of polymer performance with the incorporation of an additive into recycled polypropylene was studied by spectroscopic, rheological, optical, and mechanical characterization techniques. The results showed that after 20 recycling steps of mechanical processing of polypropylene, the main degradation processes of polypropylene are chain scission of polymer chains and oxidation, which can be improved by the addition of a stabilizing additive. It was shown that a small amount of an additive significantly improves the properties of the recycled polypropylene up to the 20th reprocessing cycle. The use of an additive improves the rheological properties of the recycled melt, surface properties, and time-dependent mechanical properties of solid polypropylene since it was shown that the additive acts as a hardener and additionally crosslinks the recycled polymer chains.

Mechanisms of Reactions between HOI and HY (Y = Cl, Br, I) on a Water Nanodroplet Surface.

Iodine chemistry has a broad range of implications for atmospheric processes including new particle formation. Hypoiodous acid (HOI) is a major iodine reservoir species. Its heterogeneous recycling in marine aerosols influences the lifetime of ozone in the troposphere. One important step of such recycling is the reaction between HOI and HY (Y = Cl, Br, I). In this article, we employ ab initio molecular dynamics (AIMD) and quantum chemistry to investigate these reactions at the surface of atmospheric aerosols. Di-halogen (XY) can be formed in a picosecond time scale, with the formation of a loop structure connected by hydrogen and halogen bonds. The photolysis of XY at the surface of an aerosol is faster than in the gas phase. In addition to the formation of di-halogen, a new pathway to forming a [H2O···I···OH2]+ complex by the direct or indirect proton transition is identified. Results presented in this study deepen our understanding of the faster iodine-heterogeneous recycling at the surface of aerosols.

Linear Characteristics of the Differences in Phase Tangents of Triple-Coil Electromagnetic Sensors and Their Application in Nonmagnetic Metal Classification.

Metal sorting is the first step in scrap metal recycling. The traditional magnetic separation method can classify ferromagnetic metals, but it is not applicable to some nonmagnetic metals with higher value. To address this situation, we propose an eddy current testing (ECT) technology-based method for classifying nonmagnetic metals. In this study, a triple-coil electromagnetic sensor, which works as two coil pairs, is tested. By analyzing the physical model of the sensor, a feature related to the conductivity of the sample under test is obtained as the difference in the tangent of the impedance changes in the two coil pairs. Additionally, we derive a linear relationship between this feature and the lift-off height, which is verified experimentally and will help to solve the classification error caused by the variation in the lift-off height. In addition, we find that the excitation frequency does not affect this linear feature. Moreover, in this study, the spectrum scanning method is converted into a single-frequency measurement, and the time consumption is greatly reduced, which improves the efficiency of the real-time metal classification system.

Lead leaching behaviors during panel-funnel glass waste separation from cathode-ray tube glass using thermosol, acid etching or mechanical cutting methods

Discarded cathode-ray tube (CRT) glass is considered harmful waste because it contains poisonous lead. Hence, a study on the disposal of CRT glass and the potential risk of lead leaching is needed. This work performs the research on the panel-funnel glass separation method, an important step for CRT glass recycling. In the thermosol method, moderate temperatures of 565 ∼ 572 °C and 5 ∼ 7 min holding time are suitable for a complete panel-funnel glass separation. The acid etching method can achieve panel-funnel glass separation with low energy consumption by using a 10 wt% nitric acid solution as an agent. Panel-funnel glass can be quickly separated by a mechanical cutting method within four minutes and achieve a high glass recovery. A glass size of 2–10 mesh, a rotary shaking speed of 240 rpm, and a retention time of 120 h can accelerate the lead leaching of 133.34 mg/L from CRT glass in the leaching solution at pH 4.93. This work gives a systematic exploration into panel-funnel glass separation and lead leaching from CRT glass, which is potentially beneficial for CRT glass waste recycling, management, and disposal.

Particle Size Reduction of Poly(ethylene terephthalate) Increases the Rate of Enzymatic Depolymerization But Does Not Increase the Overall Conversion Extent

Enzymatic depolymerization of poly(ethylene terephthalate) (PET) has emerged as a potential method for PET recycling, but extensive thermomechanical preprocessing to reduce both the crystallinity and particle size of PET is often conducted, which is costly and energy-intensive. In the current work, we use high-crystallinity PET (HC-PET) and low-crystallinity cryomilled PET (CM-PET) with three distinct particle size distributions to investigate the effect of PET particle size and crystallinity on the performance of a variant of the leaf compost-cutinase enzyme (LCC-ICCG). We show that LCC-ICCG hydrolyzes PET, resulting in the accumulation of terephthalic acid and, interestingly, also releases significant amount of mono(2-hydroxyethyl)terephthalate. Particle size reduction of PET increased the maximum rate of reaction for HC-PET, while the maximum hydrolysis rate for CM-PET was not significantly different across particle sizes. For both substrates, however, we show that particle size reduction has little effect on the overall conversion extent. Specifically, the CM-PET film was converted to 99 ± 0.2% mass loss within 48 h, while the HC-PET powder reached only 23.5 ± 0.0% conversion in 144 h. Overall, these results suggest that amorphization of PET is a necessary pretreatment step for enzymatic PET recycling using the LCC-ICCG enzyme but that particle size reduction may not be required.