Flexible electronics for heavy metal ion detection in water: a comprehensive review.

Flexible electronics offer a versatile, rapid, cost-effective and portable solution to monitor water contamination, which poses serious threat to the environment and human health. This review paper presents a comprehensive exploration of the versatile platforms of flexible electronics in the context of heavy metal ion detection in water systems. The review overviews of the fundamental principles of heavy metal ion detection, surveys the state-of-the-art materials and fabrication techniques for flexible sensors, analyses key performance metrics and limitations, and discusses future opportunities and challenges. By highlighting recent advances in nanomaterials, polymers, wireless integration, and sustainability, this review aims to serve as an essential resource for researchers, engineers, and policy makers seeking to address the critical challenge of heavy metal contamination in water resources. The versatile promise of flexible electronics is thoroughly elucidated to inspire continued innovation in this emerging technology arena.

Insights into Nitrogen-doped Carbon for Oxygen Reduction: The Role of Graphitic and Pyridinic Nitrogen Species.

Nitrogen-doped carbons (N/Cs) manifest good catalytic performance for oxygen reduction reaction (ORR) for fuel cell systems. However, to date, controversies remain on the role of active sites in N/Cs. In the present study, ORR test was conducted on three N/Cs in O2 -saturated 0.1 M KOH aqueous solution, where apparent linear correlation between graphitic N contents and ORR activity was observed. Theoretical calculations demonstrated that graphitic N doping is energetically more favorable than that of pyridinic N doping for ORR and the pyridinic N leads to more preferential with 2 e- ORR pathway. These results reveal that graphitic N plays a key role in N/Cs mediated ORR activity. This work lays a solid foundation on identifying the active sites in heteroatom-doped carbons and can be exploited for rational design and engineering of effective carbon-based ORR catalysts.

Pretreatment of sludge with sodium iron chlorophyllin-H2O2 for enhanced biogas production during anaerobic digestion.

This study investigated a novel sodium iron chlorophyllin-H2O2 (SIC-H2O2) sludge pretreatment strategy before anaerobic digestion to enhance methane production. The efficiencies and mechanism of the proposed strategy to enhance sludge biodegradability were explored. The SIC-H2O2 pretreatment could enhance the oxidation performance for sludge floc disintegration to dissociate TB-EPS into S-EPS increased SCOD to 521.38 mg/L. The increase of solubilization and release of EPS with the pretreatment facilitate the biogas production at 702 L kg-1 VS, which was 3-folds of the control and significantly higher than other pretreatments. The result of excitation-emission matrix and parallel factor (EEM-PARAFAC) analysis showed that the SIC-H2O2 pretreatment enhanced the dissociation of TB-EPS fractions, especially the protein-like and soluble microbial by-product-like substances. Electron paramagnetic resonance (EPR) results provided evidence for homolytic catalysis H2O2 for the generation OH and the production of high-valent (Por)FeIV(O) intermediates. Synergistic effects of reactive oxygen species (OH, H2O2 and /HO2) and (Por)FeIV(O) enhanced the EPS disintegration during SIC-H2O2 pretreatment. The mixed-acid type fermentation provided continuous VFAs supply under the enrichment of Chloroflexi and Actinobacteria and multiplication Methanosaeta also promoted methane production. This research provides a feasible pretreatment strategy increase sludge biodegradability and enhance biogas production in the anaerobic digestion process.

Deciphering the role of microplastic size on anaerobic sludge digestion: Changes of dissolved organic matter, leaching compounds and microbial community.

Here the role of microplastic size on dissolved organic matter, leaching compounds and microbial community during anaerobic sludge digestion was evaluated. Compared to that without the addition of polyvinyl chloride (PVC), during the 30 days' incubation, the anaerobic sludge digestion by adding PVC at the size of 75 µm and the concentration of 2.4 g/g volatile solids (VS) showed a 8.5% lower cumulative methane production, while a 17.9% higher cumulative methane production was noted by adding PVC at the size of 3000 µm and the concentration of 2.4 g/g VS. A long-term fed-batch laboratory-scale fermenter test for 147 days further testified, that higher removal efficiencies of total solids, volatile solids, and total chemical oxygen demand, and higher methane production were noted by adding PVC (2.4 g/g VS, 3000 µm) into the fermenter. More interestingly, higher concentrations of proteins, polysaccharides, volatile fatty acids, and soluble microbial by-products component were noted in the liquid phase of sludge drawn from the fermenter added with PVC since the biomass therein showed higher efficiencies of solubilization, hydrolysis, acidification, and methanogenesis. Moreover, as identified from the fermenter added with PVC, dibutyl phthalate (DBP) was the most predominant leaching phthalates compound, although the biomass therein showed a 93.4% anaerobic biodegradability of DBP. The leaching of DBP drove the predominance of microbial community towards Synergistota and Methanosaeta. More irregular elliptical shallow dimples were noted on the PVC surface after 147 days' incubation, accompanied with abundances of Proteobacteria, Actinobacteriota, Chloroflexi, Methanosaeta and Methanobacterium. The results from this study showed that the size of microplastic was a crucial factor in evaluating its impact on anaerobic sludge digestion.

Recirculation of reject water in deep-dewatering process to influent of wastewater treatment plant and dewaterability of sludge conditioned with Fe2+/H2O2, Fe2+/Ca(ClO)2, and Fe2+/Na2S2O8: From bench to pilot-scale study.

Deep dewatering of sewage sludge pretreated with advanced oxidation processes (AOPs) is a strategy for efficient sludge reduction and subsequent disposal. The pretreatment and dewatering performance of sludge conditioned with three types of AOPs (Fe2+/H2O2, Fe2+/Ca(ClO)2, and Fe2+/Na2S2O8), compared with sludge conditioned with traditional conditioner (Fe3+/CaO), were investigated in both bench and pilot-scale tests. All of those conditioner systems could reduce the water content of dewatered sludge cake to below 60 wt% in bench-scale (about 16 kg raw sludge per round) and pilot-scale (approximate 800 kg raw sludge per round) diaphragm filter press dewatering. Compared with raw sludge, the deep-dewatering filtrate after different conditioning and dewatering processes had higher ammonia nitrogen (NH4+-N) and chemical oxygen demand (COD) contents due to the degradation of organic matter, and much lower total phosphorus (TP) content due to the formation of iron phosphate precipitate. A better biodegradability (i.e. higher BOD5/COD ratio) was found in the deep-dewatering filtrate of sludge conditioned with Fe2+/H2O2 (25.2 %) and Fe2+/Ca(ClO)2 (17.4 %). Most of the heavy metals (Cr, Cu, Ni, and Pb) (>79 wt%) have remained in the dewatered sludge cake, and most of the Cl element (>90 wt%) in the sludge pretreated by Fe2+/Ca(ClO)2 and Fe3+/CaO was kept in the filtrate, rather than the dewatered sludge cake. Based on the pilot-scale experimental results, if all the filtrate in the deep-dewatering process returned to the influent of WWTP, the loading ratios of TP, NH4+-N, COD in the four conditioner systems were less than 3 wt%. The above results proved that the AOPs conditioned sludge could achieve deep-dewatering in pilot-scale and the direct recirculation of deep-dewatering filtrate to the influent of wastewater treatment plant was feasible.

Enhancing waste activated sludge dewaterability by reducing interaction energy of sludge flocs.

How to efficiently improve waste activated sludge (WAS) dewaterability is a common challenge in WAS treatment and management throughout world. The interaction energy of sludge flocs is of great importance for sludge dewaterability. In this study, the relationship among the repulsive force of sludge flocs, hydrophilic/hydrophobic characteristics of sludge flocs, and sludge dewaterability have been quantitatively and qualitatively investigated based on extended Derjaguin-Landau-Verwey-Overbeek theory for the first time. The energy barrier of sludge flocs has good correlations with sludge dewaterability (p < 0.05). Trivalent cations (Al3+ and Fe3+) and Fenton's reagent reduced the interfacial free energy (ΔG) from 9.4 mJ/m2 of raw sludge to -34.2 (Al3+), -60.5 (Fe3+), and -63.2 (Fenton) mJ/m2, respectively, indicating that the hydrophilic surfaces of the sludge flocs converted to hydrophobic (△G < 0), and decreasing Lewis acid-base interaction energy (WAB) of sludge flocs. In addition, most of the trivalent cations (Al3+ and Fe3+) were attached to sludge flocs, leading to neutralize negative charges and mitigate electrostatic interaction energy (WR) of sludge flocs. The reduction of WAB and WR eliminated energy barrier of sludge flocs and repulsive force between sludge flocs. In comparison, monovalent (Na+ and K+) and bivalent (Ca2+ and Mn2+) cations cannot completely change the hydrophilic surface characteristic and negative charge of sludge flocs. The existed energy barrier prevented sludge flocs to agglomerate with each other, thus resulting in a worse dewaterability. This study illustrated that reducing interaction energy of sludge flocs played a critical role to improve sludge dewaterability.

Improvement of sludge dewaterability by ammonium sulfate and the potential reuse of sludge as nitrogen fertilizer.

A novel method to enhance sludge dewaterability with ammonium sulfate ((NH4)2SO4) was proposed, and the potential reuse of dewatered sludge cake and filtrate as nitrogen fertilizers was evaluated. Compared with raw sludge, 87.91% reduction of capillary suction time (CST) and 88.02% reduction of specific resistance to filtration (SRF) after adding 80% (m/m) (NH4)2SO4 were achieved, with 38.49% of protein precipitated simultaneously. The (NH4)2SO4 dose destroyed cell membrane, resulting in the release of intracellular water by converting bound water into free water, thus enhancing sludge dewaterability. In the solid phase, the content of protein-N increased, and larger protein aggregates were formed. The (NH4)2SO4 dose destroyed the hydration shell, making proteins to exhibit hydrophobic interactions, and to be aggregated, and precipitated from the liquid phase. When incubated Pennisetum alopecuroides L. with the dewatered sludge cake and filtrate after dewatering and conditioning with (NH4)2SO4, the germination rate of grass seed and shoot lengths both increased while compared with those incubated with dewatered sludge cake and filtrate of the raw sludge. This study might provide insights into sustainable sludge treatment by integrating sludge dewatering and the potential reuse of dewatered sludge cake and filtrate as nitrogen fertilizer via treatment with (NH4)2SO4.

Enhanced quorum sensing of anode biofilm for better sensing linearity and recovery capability of microbial fuel cell toxicity sensor.

MFC toxicity sensor has major hindrances that limit its practical application, such as the poor concentration-response relationship and inferior recovery capability after high toxicity shock. Till now, the direct influence of intrinsic properties on the performance of MFC toxicity sensor has not been well understood. Quorum sensing (QS) is a cell-to-cell communication strategy that indirectly affects the intrinsic properties of electroactive biofilms. In this work, commercially available QS autoinducers (AHLs) were applied to MFC toxicity sensor to manipulate anode biofilm for better sensing performance. The results showed that the addition of AHLs (C6-HSL, 3-OXO-C12-HSL) led to higher sensing linearity to a wider range of Pb2+. The voltage of MFC sensors with AHLs addition fully recovered even after 10 mg/L Cu2+ shock, indicating an enhanced recovery capability of MFC toxicity sensor. It was found that higher live/dead cells ratio and increased exoelectrogen Geobacter abundance were responsible for the superior sensing linearity and recovery capability of MFC toxicity sensor. Our work presented a novel and effective way to advance the process of MFC toxicity sensor application from the perspective of EABs.

Performance evaluation of microbial fuel cell for landfill leachate treatment: Research updates and synergistic effects of hybrid systems.

Over half of century, sanitary landfill was and is still the most economical treatment strategy for solid waste disposal, but the environmental risks associated with the leachate have brought attention of scientists for its proper treatment to avoid surface and ground water deterioration. Most of the treatment technologies are energy-negative and cost intensive processes, which are unable to meet current environmental regulations. There are continuous demands of alternatives concomitant with positive energy and high effluent quality. Microbial fuel cells (MFCs) were launched in the last two decades as a potential treatment technology with bioelectricity generation accompanied with simultaneous carbon and nutrient removal. This study reviews capability and mechanisms of carbon, nitrogen and phosphorous removal from landfill leachate through MFC technology, as well as summarizes and discusses the recent advances of standalone and hybrid MFCs performances in landfill leachate (LFL) treatment. Recent improvements and synergetic effect of hybrid MFC technology upon the increasing of power densities, organic and nutrient removal, and future challenges were discussed in details.

Facile and Cost-Effective Approach for Copper Recovery from Waste Printed Circuit Boards via a Sequential Mechanochemical/Leaching/Recrystallization Process.

The recovery of copper (Cu0) from waste printed circuit boards (WPCBs) is a great challenge as a result of its heterogeneous structural properties, with a mixture of metals, epoxy resin, and fiberglass. In this study, a three-step sequential process, including mechanochemical processing, water leaching, and recrystallization, for Cu0 recovery from WPCB powder is reported. Potassium persulfate (K2S2O8), instead of acid/alkali reagents, was employed as the sole reagent in the cupric sulfate (CuSO4) regeneration process. Complete oxidation of Cu0 in the WPCBs to copper oxide (CuO) and CuSO4 was first achieved during mechanochemical processing with K2S2O8 as the solid oxidant, and the K2S2O8 was simultaneously converted to sulfate compounds [K3H(SO4)2] via a solid-solid reaction with epoxy resin (C nH mO y) as the hydrogen donator under mechanical force. The rapid leaching of Cu species in the forms of CuO and CuSO4 was therefore easily realized with pure water as a nontoxic leaching reagent. The kinetics of the leaching process of Cu species was confirmed to follow the shrinking nucleus model controlled by solid-film diffusion. Finally, CuSO4·5H2O was successfully separated by cooling crystallization of the hot saturated solution of sulfate salt [K2Cu(SO4)2·6H2O]. An efficient conversion of Cu0 to CuSO4·5H2O product, for WPCB recycling, was therefore established.

A micromilled microgrid sensor with delaminated MXene-bismuth nanocomposite assembly for simultaneous electrochemical detection of lead(II), cadmium(II) and zinc(II).

A delaminated MXene-bismuth (Bi@d-Ti3C2) nanocomposite was synthesized for the construction of a microgrid electrochemical sensor via mechanical milling. The Bi@d-Ti3C2 nanocomposite was synthesized by accumulation of Bi(III) on the surface of delaminated Ti3C2 nanosheets through electrostatic attraction and subsequent in-situ growth of bismuth nanorods. Under optimized experimental conditions, the sensor exhibits (a) linear responses to Pb(II), Cd(II) and Zn(II) in the concentration range from 1 to 20 µg L-1, (b) well separated peak potentials at -0.54 V, -0.76 V and - 1.15 V vs. Ag/AgCl, (c) sensitivities of 0.98, 0.84 and 0.60 µA L µg-1, and (d) detection limits of 0.2, 0.4 and 0.5 µg L-1, respectively. This performance is attributed to the uniform dispersion of Bi nanorods on electrically conductive delaminated Ti3C2 MXene, and to the enhanced diffusion due to the microgrid structure. Graphical abstractSchematic representation of a microgrid sensor based on delaminated MXene-bismuth (Bi@d-Ti3C2) nanocomposite for the simultaneous electrochemical determination of Pb(II), Cd(II) and Zn(II).

Stabilization and Mineralization Mechanism of Cd with Cu-Loaded Attapulgite Stabilizer Assisted with Microwave Irradiation.

Cadmium (Cd) in soil was stabilized using copper loaded attapulgite (Cu/ATP) in a microwave (MW) system. Excellent Cd stability in soil was achieved with Cu/ATP addition due to higher adsorption energy (1.38 eV) of Cu/ATP for Cd than that of ATP (∼1 eV), confirmed by density functional theory calculations. The strong hybridization of the s, p-orbitals of Cd with the s, p, d-orbitals of Cu on ATP contributed to the strong interactions between Cd and Cu/ATP. The stability performance of Cd in Cu/ATP-treated soil was further enhanced after MW irradiation through a series of phase transformation to more stable Cd-bearing crystalline minerals. The transformation was initiated by MW-induced "hot spots", which created cationic vacancy on Cu/ATP surface and enhanced the solid-state reactions between Cd and Cu/ATP framework. The total bond orders of Cd in the formed CdAl4O7 crystalline mineral elevated to 3.38, which was 5-fold higher than that for Cd on Cu/ATP, ensuring the long-term stability of Cd even after 360 curing days. Cd contaminated soil from a former industrial electroplating site was successfully stabilized with the proposed strategy. The research provides an effective stabilization strategy as well as a comprehensive understanding of the mechanism of long-term Cd stabilization.

An Emission-Free Vacuum Chlorinating Process for Simultaneous Sulfur Fixation and Lead Recovery from Spent Lead-Acid Batteries.

Spent lead-acid battery recycling by using conventional technologies is usually accompanied by releases of lead-containing wastewater as well as emissions of sulfur oxides and lead particulates that may potentially cause secondary pollution. This study developed a vacuum chlorinating process for simultaneous sulfur fixation and high-purity lead chloride (PbCl2) recovery from spent lead paste by using calcium chloride (CaCl2) and silicon dioxide (SiO2) as reagents. The process train includes pretreatment, simultaneous PbCl2 production and sulfur fixation, and PbCl2 volatilization. The pretreatment eliminated chlorine emission from direct chlorinating reaction of PbO2 in the initial S-paste (PbSO4/PbO2/PbO/Pb). During the subsequent PbCl2 production and sulfur fixation step, lead compounds in the P-paste (PbSO4/PbO) was converted to volatile PbCl2, and sulfur was simultaneously fixed to the solid residues in the form of CaSO4 to eliminate the emission of sulfur oxides. The final step, PbCl2 volatilization under vacuum, is a physical phase-transformation process of ionic crystals, following a zeroth-order kinetic model. A cost estimate indicates a profit of USD $ 8.50/kg PbCl2. This process offers a novel green lead recovery alternative for spent lead-acid batteries with environmental and economic benefits.

Simulation on flow field and gas hold-up of a pilot-scale oxidation ditch by using liquid-gas CFD model.

A liquid-gas two-phase computational fluid dynamics (CFD) model was developed to simulate flow field and gas hold-up in a pilot-scale oxidation ditch (OD). The volume of fluid (VOF) model and the mass flow inlet boundary condition for gas injection were introduced in this model. The simulated values of the flow velocities and the gas hold-up were verified by experimental measurements in the pilot-scale OD. The results showed that the gas hold-up at test-site 3, immediately downstream of the surface aerator, was the highest among all three test-sites. Most of the gas existed in the upper portion of the ditch and was close to the inner side of the channel. Based on the liquid-gas two-phase CFD model, three operating conditions with different setting height ratios of the submerged impellers were simulated. The simulated results suggested that the setting heights of the submerged impellers have significant impacts on the flow velocity distribution. Lowering the setting height could increase the flow velocity in the pilot-scale OD. An optimal setting height ratio of 0.273 was proposed, which would be beneficial for minimizing sludge sedimentation, especially near the inner side of the curve bend.

Syrosingopine and UK5099 synergistically suppress non-small cell lung cancer by activating the integrated stress response.

Non-small cell lung cancer (NSCLC) presents a global health challenge due to its low five-year survival rates, underscoring the need for novel therapeutic strategies. Our research explored the synergistic mechanisms of syrosingopine and UK-5099 in treating NSCLC. In vitro experiments showed that the combination of syrosingopine and UK-5099 significantly synergized to suppress NSCLC proliferation. Further experiments revealed that this combination induced cell cycle arrest and promoted apoptosis in NSCLC cells. In vivo experiments demonstrated that the combination of syrosingopine and UK-5099 markedly inhibited tumor growth. Mechanistic studies revealed that this drug combination promoted mitochondrial damage by inducing lactate accumulation and oxidative stress. Additionally, the combination triggered an integrated stress response (ISR) through the activation of heme-regulated inhibitor kinase (HRI). Importantly, our findings suggested that the synergistic suppression of NSCLC by syrosingopine and UK-5099 was dependent on ISR activation. In summary, our study proposed a promising therapeutic approach that involved the combination of Syrosingopine and UK-5099 to activate ISR, significantly hindering NSCLC growth and proliferation.

Peroxymonosulfate activation by trace iron(III) porphyrin for facile degradation of organic pollutants via nonradical oxidation.

Nonradical species with great resistance to interference have shown great advantages in complex wastewater treatment. Herein, a novel system constructed by biodegradable tetrakis-(4-carboxyphenyl)-porphyrinatoiron(III) (FeIII-TCPP) and peroxymonosulfate (PMS) was proposed for facile decontamination. Nonradical pathway is observed in FeIII-TCPP/PMS, where 1O2 and high-valent iron-oxo species play dominant roles. The genres and valence of high-valent iron-oxo species, including iron(IV)-oxo porphyrin radical-cationic species [OFeIV-TCPP•+] and iron(IV)-hydroxide species [FeIV-TCPP(OH)], are ascertained, along with their generation mechanism. The axial ligand on the iron axial site affects the ground spin state of FeIII-TCPP, further influencing the thermodynamic reaction pathway of active species. With trace catalyst in micromoles, FeIII-TCPP exhibits high efficiency by degrading bisphenol S (BPS) completely within 5 min, while Co2+/PMS can only achieve a maximum of 26.2% under identical condition. Beneficial from nonradical pathways, FeIII-TCPP/PMS demonstrates a wide pH range of 3-10 and exhibits minimal sensitivity to interference of concomitant materials. BPS is primarily eliminated through ß-scission and hydroxylation. Specifically, 1O2 electrophilically attacks the C-S bond of BPS, while high-valent iron-oxo species interacts with BPS through an oxygen-bound mechanism. This study provides novel insights into efficient activation of PMS by iron porphyrin, enabling the removal of refractory pollutants through nonradical pathway.

Formation mechanism of persistent free radicals during pyrolysis of Fenton-conditioned sewage sludge: Influence of NOM and iron.

The present study provided an innovative insight into the formation mechanism of persistent free radicals (PFRs) during the pyrolysis of Fenton-conditioned sludge. Fenton conditioners simultaneously improve the dewatering performance of sewage sludge and catalyze the pyrolysis of sewage sludge for the formation of PFRs. In this process, PFRs with a total number of spins of 9.533×1019 spins/g DS could be generated by pyrolysis of Fenton-conditioned sludge at 400°C. The direct thermal decomposition of natural organic matter (NOM) fractions contributed to the formation of carbon-centered radicals, while the Maillard reaction produced phenols precursors. Additionally, the reaction between aromatic proteins and iron played a crucial role in the formation of phenoxyl or semiquinone-type radicals. Kinetics analysis using discrete distributed activation energy model (DAEM) demonstrated that the average activation energy for pyrolysis was reduced from 178.28 kJ/mol for raw sludge to 164.53 KJ/mol for Fenton conditioned sludge. The reaction factor (fi) indicated that the primary reaction in Fenton-conditioned sludge comprised of 27 parallel first-order reactions, resulting from pyrolysis cleavage of the NOM fractions, the Maillard reaction, and iron catalysis. These findings are significant for understanding the formation process of PFRs from NOM in Fenton-conditioned sludge and provide valuable insight for controlling PFRs formation in practical applications.

Deep dewatering of sludge and resource recovery of hydroxyapatite: A recyclable approach via ionic liquid biphasic system and hydrogen bonds reformation.

Deep dewatering of Waste Activated Sludge (WAS) through mechanical processes remains inefficient, primarily due to the formation of a stable hydrogen bonding network between the biopolymers and water, which consequently leads to significant water trapped by Extracellular Polymeric Substances (EPS). In this study, a novel and recyclable treatment for WAS based on Ionic Liquids (ILs) was established, named IL-biphasic aqueous system (IL-ABS) treatment. Specifically, the IL-ABS formed in WAS facilitated rapid and efficient in-situ deep dewatering while concurrently recovering hydroxyapatite. The water content decreased from an initial 98.27 % to 65.35 % with IL-ABS, formed by 1-Butyl-3-methylimidazolium bromide (BmimBr) and K3PO4 synthesized from waste H3PO4. Moreover, the recycled BmimBr maintaining the water content of the dewatered sludge consistently between 65.61 % and 67.25 % across five cycles, exhibited remarkable reproducibility. Through three-dimensional excitation-emission matrix, lactate dehydrogenase analyses and confocal laser scanning microscopy, the high concentration of BmimBr in the upper phase effectively disrupted the cells and EPS, which exposed protein and polysaccharide on the EPS surface. Subsequently, the K3PO4 in the lower phase led to an enhanced salting-out effect in WAS. Furthermore, FT-IR analysis revealed that K3PO4 disrupted the original hydrogen bonds between EPS and water. Then, BmimBr formed numerous hydrogen bonds with the sludge flocs, leading to deep dewatering and agglomeration of the sludge flocs during the unique phase separation process of IL-ABS. Notably, sludge-derived hydroxyapatite product exhibited remarkable adsorption capacity for prevalent heavy metal contaminants such as Pb2+, Cd2+ and Cu2+, with efficiencies comparable to those of commercial hydroxyapatite, thereby achieving the resource utilization of waste H3PO4. Moreover, economic calculations demonstrated the suitability of this novel treatment. This innovative treatment exhibits potential for practical applications in the non-mechanical deep dewatering of WAS.

[Effect and mechanism of polyphyllin I on human cervical cancer cell HeLa in vitro].

OBJECTIVE: To study the effect and mechanism of polyphyllin I on human cervical cancer cell HeLa. METHODS: The cell growth and proliferation effect of Polyphyllin I on HeLa cells were measured by MTT assay; Hoechst 33258 fluorescent staining was used to record changes in cell morphology and morphological changes in mitochondria of Polyphyllin I before and after treatment on He La cells. Annexin V-FITC/PI staining was used to detect the ratio of tumor cell apoptosis by flow cytometry. Release of intracellular re active oxygen species (ROS) generation level in HeLa cells was determined by flow cytometry,Caspase-3 activity was measured by fluorescent assay kits. RESULTS: MTT results showed that Polyphyllin I could significantly suppressed the proliferation of HeLa cells and in time-and concentration-dependence manner. The intracellular ROS levels were increased dramatically and the mitochondrial membrane was decreased consistently. Caspase-3 proteins expression levels were increased after Polyphyllin I treatment. CONCLUSION: Polyphyllin I could inhibit HeLa cells growth and proliferation and its mechanism may be related to inducing cell apoptosis.

Enhanced bromine fixation and tar lightweighting in co-pyrolysis of non-metallic fractions of waste printed circuit boards with Bayer red mud.

A co-pyrolysis process for non-metallic fractions (NMFs) from WPCBs with Bayer red mud (RM) is proposed to upgrade pyrolysis products in this study. High bromine fixation efficiency was realized, and higher content of lightweight pyrolysis tar was obtained. The mechanism of catalytic pyrolysis and simultaneous bromine fixation of NMFs by RM was investigated by experiments and theoretical calculations. The three inorganic components of Fe2O3, CaCO3 and Al2O3 in RM played key roles in the catalytic pyrolysis of NMFs, and their order of catalytic debromination effect was CaCO3 > Fe2O3 > Al2O3. By adding 15 wt% RM, the pyrolysis solid residue could fix 89.55 wt% bromine, compared with 35.42 wt% of NMFs without adding RM, due to the formation of FeBr2 and CaBr2 from Fe2O3 and CaCO3 in RM, respectively. Tar lightweighting was realized by reducing the energy barrier of the direct decomposition of tetrabromobisphenol A (TBBPA) in NMFs. The order of effect of the three key components on the tar lightweighting was Fe2O3 > Al2O3 > CaCO3. The content of lightweight tar in the tar obtained by catalytic pyrolysis of NMFs with 15 wt% RM was 44.29% higher than that in the tar obtained by direct pyrolysis of NMFs. This work provides a theoretical guidance for the low-cost and eco-friendly recycling of e-wastes by co-pyrolysis with RM.