Spin-selected bifunctional metasurface for grayscale image and metalens.

With the extensive research on the Pancharatnam-Berry phase, metasurfaces have been widely designed as various cross-polarized nanodevices for circularly polarized (CP) illumination. However, co- and cross-polarized lights are rarely co-modulated by the metasurface. To fully utilize the transmitted light, we propose a spin-selected bifunctional metasurface composed of arrayed silver nanorods, integrating an amplitude-based grayscale imaging for co-polarized transmission and a phase-based metalens for cross-polarized transmission, under left-handed CP incidence. Moreover, such dual functionalities work well under right-handed CP incidence. Both experiments and simulations demonstrate the bifunctional performance as potential meta-devices.

DTCO optimizes critical path nets to improve chip performance with timing-aware OPC in deep ultraviolet lithography.

Design technology co-optimization (DTCO) is a potential approach to tackle the escalating expenses and complexities associated with pitch scaling. This strategy offers a promising solution by minimizing the required design dimensions and mitigating the pitch scaling trend. It is worth noting that lithography has played a significant role in dimensional scaling over time. This paper proposes a DTCO flow to reduce the impact of the process variation (PV) band and edge placement error (EPE). First, we performed the digital back-end design of the high-performance processor and got the test layout; second, we executed timing analysis on the test layout to get the critical path net that affects the chip performance; third, we proposed the timing-aware optimized optical proximity correction (OPC) method to optimize the PV band and EPE by adjusting the weights of critical path net merit points, optimizing the generation of the sub-resolution assistant feature, giving tighter EPE specs for merit points on the critical path net, and placing denser merit points as well as denser breakpoints for the critical path net to obtain greater freedom in the OPC process. Finally, it is verified that our proposed DTCO process can significantly reduce the EPE and lead to a slight decrease in the PV band of the chip while maintaining the same process windows.

Clinical and dermatoscopic features of temporal triangular alopecia in infants.

OBJECTIVE: To summarize the clinical and dermatoscopic features of temporal triangular alopecia in infants and explore the clinical significance of dermatoscopy in the diagnosis of triangular alopecia temporalis in infants. METHODS: A retrospective analysis was performed on 20 children with temporal triangular alopecia diagnosed in the dermatology clinic of Tianjin Children's Hospital from January 2015 to December 2021. Dermatoscopy was performed on all children, and images were collected. RESULTS: The clinical features of 20 children were 15 males and five females, all of which were born immediately after birth; There were eight cases (40%) in the left temporal region, 10 cases (50%) in the right temporal region, one case (5%) in the head region, and one case (5%) in the occipital region; 19 cases were single (95%), one case was multiple (5%); There were 21 skin lesions, 15 triangular lesions (71.4%), four quasi-circular lesions (19%), and two lance-shaped lesions (9.5%). Trichoscopic features: The hair follicle opening in all skin lesions is normal, and the hair follicle opening can be seen with fluffy hair (vellus hair). The vellus hair is evenly distributed, and the length is diverse (both short and long vellus hair exist in the same hair loss area). There are 14 cases of white vellus hair (70%), five cases of white spots (25%), one case of honeycomb pigment pattern (5%), and one case of vascular dilation pattern (5%). CONCLUSION: Temporal triangular alopecia in infants has typical clinical and dermatoscopic characteristics, and the dermatoscopy can provide clinical basis for its diagnosis and differential diagnosis.

Performance Optimization for a Class of Petri Nets.

Petri nets (PNs) are widely used to model flexible manufacturing systems (FMSs). This paper deals with the performance optimization of FMSs modeled by Petri nets that aim to maximize the system's performance under a given budget by optimizing both quantities and types of resources, such as sensors and devices. Such an optimization problem is challenging since it is nonlinear; hence, a globally optimal solution is hard to achieve. Here, we developed a genetic algorithm combined with mixed-integer linear programming (MILP) to solve the problem. In this approach, a set of candidate resource allocation strategies, i.e., the choices of the number of resources, are first generated by using MILP. Then, the choices of the type and the cycle time of the resources are evaluated by MILP; the promising ones are used to spawn the next generation of candidate strategies. The effectiveness and efficiency of the developed methodology are illustrated by simulation studies.

Genomic Scar Score: A robust model predicting homologous recombination deficiency based on genomic instability.

OBJECTIVE: To develop a novel machine learning-based algorithm called the Genomic Scar Score (GSS) for predicting homologous recombination deficiency (HRD) events. DESIGN: Method development study. SETTING: AmoyDx Medical Laboratory and Jiangsu Cancer Hospital. POPULATION OR SAMPLE: A cohort of individuals with ovarian or breast cancer (n = 377) were collected from the AmoyDx Medical Laboratory. Another cohort of patients with ovarian cancer treated with PARP inhibitors (n = 58) was enrolled in the Jiangsu Cancer Hospital. METHODS: We used linear support vector machines to build a Genomic Scar (GS) model to predict HRD events, and Kaplan-Meier analyses were performed by comparing the progression-free survival (PFS) of patients in different groups using a two-sided log-rank test. MAIN OUTCOME MEASURES: The performance of the GS model and the result of clinical validation. RESULTS: The GS model displayed more than 97.0% sensitivity to detect BRCA-deficient events, and the GS model identified patients that could benefit from poly(ADP-ribose) polymerase inhibitors (PARPi), as the GS score (GSS)-positive group had a longer progression-free survival (PFS) (9.4 versus 4.4 months; hazard ratio [HR] = 0.54, P < 0.001) than the GSS-negative group after PARPi treatment. Meanwhile, the GSS showed high concordance among different NGS panels, which implied the robustness of the GS model. CONCLUSIONS: The GS was a robust model to predict HRD and had broad clinical applications in predicting which patients will respond favourably to PARPi treatment.

Large-area mid-infrared broadband absorbers based on spiral ITO resulting from the combination of two different broadening absorption methods.

A large-area mid-infrared broadband absorber is proposed in this paper. The absorber is a spiral ITO structure grown on a hexagonal lattice arrangement of silicon nanopillars by using a glancing angle deposition method. The experimental results show that when the heights of the silicon nanopillars are 1.7 µm and the number of rotation depositions is n = 5, that is, the rotation angle is 150 degrees, the absorber absorbs more than 81% of electromagnetic waves in the 2.5-6 µm spectral range. In the atmospheric window of 3-5 µm, the integral absorption reaches 96%. The experimental results also show that the absorbing ability of the ITO structure in the mid-infrared atmospheric window is significantly stronger than that of the structure composed of silver under the same preparation conditions. The main reasons for the broadband absorption are that the spiral ITO structure has resonant absorption of electromagnetic waves with different wavelengths in the empty cavity regions with different sizes, and ITO has longer penetration depths than noble metals in the mid-infrared band, which brings about stronger broadband absorption. The combination of the two leads to a broadening of the total absorption spectrum. The higher heights of the silicon nanopillars enhance absorption further. Additionally, the loose spiral ITO distributions indicate lower mean plasma concentration and then increase penetration depths further, resulting in stronger light absorption. Such a large-area mid-infrared absorption structure with a simple preparation method has potential applications in mid-infrared cloaking and sensing.

Jones pupil decomposition and its lithographic imaging impacts.

The Jones pupil is a full description of imaging properties of projection lenses in optical lithography. The decomposition of the Jones pupil into components with clear physical meanings was studied previously; however, the decomposition method has not been studied systematically. To generalize the existing decomposition method, this work is aimed at finding all the decomposition methods and analyzing the lithographic imaging impacts. In this work, six decomposition methods are proposed, and the lithographic imaging impacts of the Jones components are studied and compared for all the decomposition methods. The results demonstrate that, although the decomposition methods are different, their lithographic impacts are identical. To be specific, apodization has a dominant impact on the critical dimension with a magnitude of 1.3 nm, and the impact of diattenuation is 0.3 nm. In contrast, the impacts of the other Jones components of aberration, birefringence, rotator, and ellipticity are negligible. This work gives a complete understanding of the imaging impacts of the Jones pupil.

Critical pattern selection method for full-chip source and mask optimization.

Source and mask optimization (SMO) is one of the most important resolution enhancement techniques for integrated circuit manufacturing in 2X nm technology node and beyond. Nowadays full-chip SMO is alternatively realized by applying SMO to limited number of selected critical patterns instead of to full-chip area, since it is too computational expensive to be apply SMO in full-chip area directly. The critical patterns are selected by a pattern selection method which enables SMO in full-chip application by balancing the performance and computation consumption. A novel diffraction-based pattern selection method has been proposed in this paper. In this method, diffraction-signatures are sufficiently described with widths in eight selected directions. Coverage rules between the diffraction-signatures are specifically designed. Diffraction-signature grouping method and pattern selection strategy are proposed based on the diffraction-signatures and coverage rules. A series of simulations and comparisons performed using ASML's Tachyon software, which is one of the state of the art commercial SMO platforms, verify the validity of the proposed method.

Efficacy of platinum in advanced triple-negative breast cancer with germline BRCA mutation determined by next generation sequencing.

OBJECTIVE: To compare the efficacy of platinum- and non-platinum-based regimens as first-line treatment for advanced triple-negative breast cancer (TNBC) and analyze the relationship between their efficacy and BRCA gene status. METHODS: Retrospectively analyze clinical data of 220 patients diagnosed pathologically with advanced TNBC and treated at the Department of Breast Oncology, Peking University Cancer Hospital from 2013 to 2018 and evaluate the efficacy of chemotherapy. A total of 114 patients had BRCA1/2 gene tested by next generation sequencing (NGS) using peripheral blood, and we analyzed the correlation between their efficacy and BRCA1/2 gene status. RESULTS: Non-platinum-based chemotherapy (NPCT) was administered to 129 and platinum-based chemotherapy (PBCT) to 91 study patients. The clinical benefit rate (CBR) and median progression-free survival (PFS) were not statistically different between NPCT and PBCT groups. The median overall survival (OS) was 30.0 and 22.5 months for PBCT and NPCT group, respectively [P=0.090, hazard ratios (HR)=0.703]. BRCA status was assessed in 114 patients, 14 of whom had deleterious germline BRCA1/2 (gBRCA) mutations (seven in each group). In PBCT group, the CBR was 85.7% and 35.1% for patients with and without deleterious gBRCA mutations, respectively (P=0.039). The median PFS were 14.9 and 5.3 months and median OS were 26.5 and 15.5 months for patients with and without deleterious gBRCA mutations, respectively (P=0.001, P=0.161, respectively). Patients in PBCT group had significantly greater rates of grade 3-4 anemia (5.5%vs. 0%) and thrombocytopenia (8.8% vs. 0%), whereas palmar-plantar erythrodysesthesia (12.4% vs. 0%) and peripheral neuropathy (8.6% vs. 1.1%) occurred more frequently in NPCT group. CONCLUSIONS: Platinum-based regimens are more effective in patients with deleterious gBRCA mutations, but no difference in patients without BRCA gene mutations, so non-platinum is an option in patients without BRCA gene mutations considering the toxicity and side effect. And we recommend that patients with advanced TNBC should have BRCA gene test.

High phylogenetic diversity and abundance pattern of Labyrinthulomycete protists in the coastal waters of the Bohai Sea.

The unicellular Labyrinthulomycete protists have long been considered to play a significant role in ocean carbon cycling. However, their distribution and biogeochemical function remain poorly understood. We present a large-scale study of their spatiotemporal abundance and diversity in the coastal waters of Bohai Sea using flow cytometry and high-throughput sequencing. These protists display niche preferences and episodic higher biomass than that of bacterioplankton with much phylogenetic diversity (> 4000 OTUs) ever reported. They were ubiquitous with a typical abundance range of 100-1000 cells ml-1 and biomass range of 0.06-574.59 µg C L-1 . The observed spatiotemporal abundance variations support the current 'left-over scavengers' nutritional model and highlight these protists as a significant component of the marine microbial loop. The higher average abundance and phylogenetic diversity in the nearshore compared with those in the offshore reveal their predominant role in the terrigenous matter decomposition. Furthermore, the differential relationship of the protist genera to environmental conditions together with their co-occurrence network suggests their unique substrate preferences and niche partitioning. With few subnetworks and possible keystone species, their network topology indicates community resilience and high connectance level of few operational taxonomic units (OTUs). We demonstrate the significant contribution of these protists to the secondary production and nutrient cycling in the coastal waters. As secondary producers, their role will become more important with increasingly coastal eutrophication.

A 3-dimensional C/CeO2 hollow nanostructure framework as a peroxidase mimetic, and its application to the colorimetric determination of hydrogen peroxide.

Various 3-dimensional C/CeO2 hollow nanostructure frameworks (3D C/CeO2 HNFs) were synthesized by using a polymer blowing process that is accelerated by adding a certain amount of cerium nitrate. Polyvinylpyrrolidone was used as the polymer. The resulting HNFs were characterized by scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy. The HNFs possess a large specific surface area, and the CeO2 nanocrystals consist of a single phase. The HNFs display intrinsic peroxidase-like activity and can catalyze the oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine in the presence of H2O2 to produce a blue product. The method was applied to the quantification of H2O2 with a 5.2 nM detection limit. The analytical range is from 10 nM to 1 µM. Graphical abstract Schematic of the preparation of a 3-dimensional C/CeO2 hollow nanostructure framework by a polyvinylpyrrolidone-blowing process accelerated by Ce(NO3)3. They were applied to H2O2 detection by catalyzing the oxidation of peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) to the oxidized 3,3',5,5'-tetramethylbenzidine (oxTMB) to produce blue-color reaction.

[Design and implementation of command system for emergency events of parasitic diseases].

Based on the requirement analysis and functional design of the command system for parasitic disease outbreaks, the system was constructed by workflow technique, function modules and technical architecture. The command system was a multi-platform system, could achieve multiple functions, such as monitoring and early warning of parasitic diseases, emergency video communication, emergency dispatcher, and emergency management. The system can meet the needs in emergency events of parasitic diseases, and increase preparedness level.

A novel 3D nitrogen-doped porous carbon supported Fe-Cu bimetallic nanoparticles composite derived from lignin: an efficient peroxymonosulfate activator for naphthalene degradation.

A novel 3D nitrogen-doped porous carbon supported Fe-Cu bimetallic nanoparticles composite (Fe-Cu-N-PC) was prepared via direct pyrolysis by employing black liquor lignin as a main precursor, and it was utilized as a novel catalyst for PMS activation in degrading naphthalene. Under the optimum experimental conditions, the naphthalene degradation rate was up to 93.2% within 60 min in the Fe-Cu-N-PC/PMS system. The porous carbon framework of Fe-Cu-N-PC could facilitate the quick molecule diffusion of reactants towards the inner bimetallic nanoparticles and enriched naphthalene molecules from the solution by a specific adsorption, which increased the odds of contact between naphthalene and reactive oxygen species and improved the reaction efficiency. The quenching reaction proved that the non-free radical pathway dominated by 1O2 was the main way in naphthalene degradation, while the free radical pathway involving SO4·- and ·OH only played a secondary role. Moreover, owing to its high magnetization performance, Fe-Cu-N-PC could be magnetically recovered and maintained excellent naphthalene degradation rate after four degradation cycles. This research will offer a theoretical basis for the construction of facile, efficient, and green technologies to remediate persistent organic pollutants in the environment.

Degradation and mechanism of PFOA by peroxymonosulfate activated by nitrogen-doped carbon foam-anchored nZVI in aqueous solutions.

Perfluorooctanoic acid (PFOA) is an emerging pollutant that is non-biodegradable and presents severe environmental and human health risks. In this study, we present an effective and mild approach for PFOA degradation that involves the use of nitrogen-doped carbon foam anchored with nanoscale zero-valent iron (nZVI@NCF) to activate low concentration peroxymonosulfate (PMS) for the treatment. The nZVI@NCF/PMS system efficiently removed 84.4% of PFOA (2.4 µM). The active sites of nZVI@NCF including Fe0 (110) and graphitic nitrogen played crucial roles in the degradation. Electrochemical analyses and density functional theory calculations revealed that nZVI@NCF acted as an electronic donor, transferring electrons to both PMS and PFOA during the reaction. By further analyzing the electron paramagnetic resonance and byproducts, it was determined that electron transfer and singlet oxygen were responsible for PFOA degradation. Three degradation pathways involving decarboxylation and surface reduction of PFOA in the nZVI@NCF/PMS system were determined. Finding from this study indicate that nZVI@NCF/PMS systems are effective in degrading PFOA and thus present a promising persulfate-advanced oxidation process technology for PFAS treatment.

A novel aminated lignin/geopolymer supported with Fe nanoparticles for removing Cr(VI) and naphthalene: Intermediates promoting the reduction of Cr(VI).

A novel, inexpensive and eco-friendly aminated lignin/geopolymer supported with Fe nanoparticles (Fe@N-L-GM) composite was successfully synthesized using kaolin and lignin as the major precursors. The prepared Fe@N-L-GM had larger specific surface area, rich oxygen-containing and nitrogen-containing functional groups, greater electron transfer ability and interconnective porous structure. The Fe@N-L-GM could be employed as the adsorbent of Cr(VI) and the activator of potassium peroxymonosulfate (PMS) for treatment of Cr(VI) and naphthalene (NAP) in wastewater. The adsorption and degradation results indicated that the maximum adsorption capacity of Cr(VI) could reach 65.83 mg g-1, whereas the maximum NAP degradation efficiency could reach 97.81 %. The adsorbed Cr(VI) was mostly converted to the low toxic Cr(III) through the reduction of electron donors such as Fe(II), amino and hydroxyl groups. The quenching experiment results confirmed that ·OH might be the crucial ROSs in mediating NAP degradation. In the simultaneous removal experiment of Cr(VI) and NAP, the Cr(VI) removal rate was significantly improved in the presence of NAP, while phenol as the degradation intermediate of NAP might be the main substance for promoting the reduction of Cr(VI). This work provided the theoretical foundation and a new type of material for the simultaneous removal of heavy metal and persistent organic pollutants (POPs).

A detection method of typical toxic mixed red tide algae in Qinhuangdao based on three-dimensional fluorescence spectroscopy.

Red tides occur every year in the Qinhuangdao sea area of China, including a variety of toxic algae and non-toxic algae. Toxic red tide algae have caused great damage to the marine aquaculture industry in China and seriously endangered human health, but most of non-toxic algae are important bait for marine plankton. Therefore, it is very important to identify the type of mixed red tide algae in Qinhuangdao sea area. In this paper, three-dimensional fluorescence spectroscopy and chemometrics were applied to the identification of typical toxic mixed red tide algae in Qinhuangdao. Firstly, the three-dimensional fluorescence spectrum data of typical mixed red tide algae in Qinhuangdao sea area were measured by f-7000 fluorescence spectrometer, and the contour map of algae samples was obtained. Secondly, the contour spectrum analysis is carried out to find the excitation wavelength of the peak position of the three-dimensional fluorescence spectrum and form the new three-dimensional fluorescence spectrum data selected by the feature interval. Then, the new three-dimensional fluorescence spectrum data are extracted by principal component analysis (PCA). Finally, the feature extraction data and the data without feature extraction are used as the input of the genetic optimization support vector machine (GA-SVM) and particle swarm optimization support vector machine (PSO-SVM) classification models, respectively, to obtain the classification model of mixed red tide algae, and the two feature extraction analysis methods and two classification algorithms are compared. The results show that the classification accuracy of the test set using the principal component feature extraction and GA-SVM classification method is 92.97 %, when the excitation wavelengths are 420 nm, 440 nm, 480 nm, 500 nm and 580 nm, and the emission wavelengths are 650-750 nm. Therefore, it is feasible and effective to apply the three-dimensional fluorescence spectrum characteristics and genetic optimization support vector machine classification method to the identification of toxic mixed red tide algae in Qinhuangdao sea area.

A low-cost and eco-friendly powder catalyst: Iron and copper nanoparticles supported on biochar/geopolymer for activating potassium peroxymonosulfate to degrade naphthalene in water and soil.

A low-cost and environment-friendly biochar/geopolymer composite loaded with Fe and Cu nanoparticles (Fe-Cu@BC-GM) was prepared by impregnation-calcination using lignin and kaolin as precursors. SEM, FTIR and XRD analysis suggested that the Fe-Cu@BC-GM had a certain pore structure, rich functional groups and stable crystal structure. The obtained Fe-Cu@BC-GM was used as the catalyst of potassium peroxymonosulfate (PMS) for remediation of wastewater and soil polluted by naphthalene (NAP). Experimental results indicated that Fe-Cu@BC-GM exhibited outstanding catalytic performance, and the maximum degradation rate of NAP in water and soil reached 98.35% and 67.98% within 120 min, respectively. The XPS measurement confirmed the presence of successive Fe (Ⅲ)/Fe (Ⅱ) and Cu(Ⅱ)/Cu(Ⅰ) redox pairs cycles on the surface of Fe-Cu@BC-GM, which made Fe (Ⅲ) and Cu(Ⅰ) continuously generated Fe (Ⅱ) activating PMS to produce SO4·- and ·OH for the degradation of NAP. The effects of Fe-Cu@BC-GM/PMS system on plant toxicity were evaluated by analyzing the degradation intermediates and bioassay of mung bean. It was proved that the Fe-Cu@BC-GM/PMS system could degrade NAP into less toxic intermediates, and the seed germination rate, root and stem length of mung bean after soil remediation were not notably different from those of the uncontaminated soil. This work opened new prospect for the application of geopolymer in degradation of persistent organic pollutants (POPs) and provided a cost-effective option for the remediation of the persistent organic pollutants contaminated water and soil.

Core-shell structural nitrogen-doped carbon foam loaded with nano zero-valent iron for simultaneous remediation of Cd (II) and NAP in water and soil: Kinetics, mechanism, and environmental evaluation.

An economical, efficient, and environmentally friendly technology was developed for simultaneous remediation of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in soil and water. In this study, using pinecones powder as the precursor, the core-shell structural nitrogen-doped carbon foam loaded with nano zero-valent iron (nZVI@NCF) was synthesized through Mannich reaction and high-temperature carbon reduction. The nZVI@NCF was applied as the adsorbent and catalyst to simultaneously remediate the composite pollutants of Cd (II) and naphthalene (NAP). Under the optimal conditions, the adsorption capacity of Cd (II) in water and soil were 13.9 mg·g-1 and 1.97 mg·g-1, respectively, and the adsorption process conformed to the pseudo-second-order kinetic model. The degradation rates of NAP in water (10 mg·L-1) reached almost 100% as well as it could reach 59.12% in soil (10 mg·kg-1). In addition, it was proved that the presence of NAP could compete with Cd (II) for the active sites on the surface of the material to inhibit the adsorption of Cd (II), while the co-existence of Cd (II) could improve the degradation of NAP by the nZVI@NCF/PMS system due to the nZVI-Cd bimetallic effect and the pro-oxidant effect of Cd (II) promoting the generation of ROS. The free radical quenching experiment revealed that the generated ·O2- was the main substance that mediated the redox of nZVI/Fe2+/Fe3+ to oxidative NAP during the degradation process. Furthermore, the results of the phytotoxicity test demonstrated that the nZVI@NCF/PMS system could effectively remediate the soil co-contaminated with Cd (II) and NAP as well as improve the soil environment quality. This research will provide new materials and potential technologies for the efficient treatment of the composite pollutants in the environment.

Iron nanoparticles supported on N-doped carbon foam with honeycomb microstructure: An efficient potassium peroxymonosulfate activator for the degradation of fluoranthene in water and soil.

A promising technology was developed for the remediation of fluoranthene (FLT) contaminated water and soil. Specifically, iron nanoparticles supported on N-doped carbon foam (Fe@CF-N) was synthesized by in-situ impregnation and a unique calcination process using pine cone as the precursor. The obtained Fe@CF-N was used as an activator of potassium peroxymonosulfate (PMS) to degrade FLT in water and soil. According to experimental results, Fe@CF-N had a three-dimensional network structure with a large specific surface area of 249.0 m2 g-1, displaying excellent catalytic performance. The maximum removal efficiency of FLT in water and soil reached 81.83% and 78.12% within 180 min, respectively. After four consecutive degradation cycles, the removal efficiency of FLT in water was still 55%. Electron spin resonance (ESR) measurements showed that hydroxyl radicals (·OH), sulfate radical (SO4-·) and 1O2 were the major reactive oxygen species (ROS). A series of low molecular weight intermediates were generated during the FLT degradation progress, such as C6H6O3 and C3H8O2. The effect of Fe@CF-N/PMS system on the phytotoxicity was evaluated via bioassay based on peas. The results indicated that seed germination rate and root shoot elongation of remediated soil by Fe@CF-N/PMS system were not significantly different from those of noncontaminated soil. This study provided a cost-effective remediation option for PAHs contaminated water and soil.

[Effect of Different Cationic Polyacrylamide Organic Dehydrating Agents on Sludge Dewatering Performance].

To study the effect of different cationic polyacrylamide organic dehydrating agents on sludge dewatering performance, eight commercially available cationic polyacrylamides of the same series with different properties were used. Based on the different cationic degree, they were named 9101, 9102, 9103, 9104, 9106, 9108, 9110, and 9112, respectively. Their properties were characterized by instruments and chemical analysis, and the indexes of sludge after treatment were also measured. The results showed that the properties of the eight organic dehydrants were different, among which the charge density, cationicity, viscosity, and Zeta potential had homologous trends, which all increased gradually from 9101 to 9112. The four indexes of 9112 were as high as 2.98 meq·L-1, 17.42%, 85.07 mPa·s, and 67.10 mV, respectively. The dewatering performance of sludge was improved by improving the specific resistance of filtration (SRF), floc properties, viscosity, Zeta potential, the bound water content, and the distribution of extracellular polymeric substances (EPS) after dosing organic dewatering agents. The results showed that the viscosity, charge density, cationic degree, and Zeta potential of the dewatering agents had a great influence on the sludge dewatering performance. The SRF of sludge was negatively correlated with the viscosity of the organic dewatering agent, and the correlation coefficient was as high as 0.92025, indicating that the sludge dewatering performance was improved mainly through the adsorption bridging effect of the organic dewatering agent in sludge dewatering.