Effect of bone marrow mesenchymal stem cell transplantation combined with lugua polypeptide injection on osteoarthritis in rabbit knee joint.

PURPOSE: This study aimed to elucidate the effect of bone marrow mesenchymal stem cell (BMSC) transplantation combined with the administration of Lugua polypeptide injection into the knee joint cavity to treat knee osteoarthritis (KOA) in rabbits. MATERIAL AND METHODS: Sixty white New Zealand rabbits were randomly divided into the blank, model, Lugua polypeptide, BMSC, and combined (Lugua polypeptide plus BMSC) groups, with 12 rabbits in each group. The mRNA and protein expression levels of cyclin D1, bcl-2, TIMP-1, p21, caspase-3, Bax, MMP-1, MMP-13, TLR-4, and NF-κB p65 in chondrocytes, and levels of IL-1, NO, TNF-α, and IL-6 in the synovial fluid were compared. RESULTS: The severity of cartilage damage in the combined group was significantly less (P <0.01). Compared to the MG, the mRNA and protein expression levels of cyclin D1, bcl-2 and TIMP-1 in chondrocytes of the three other groups were significantly increased, while those of p21, caspase-3, Bax, MMP-1, MMP-13, TLR-4, and NF-κB p65 in the chondrocytes and levels of IL-1, NO, TNF-α, and IL-6 in the synovial fluid of the three other groups were significantly reduced (P <0.05). The aforementioned indicators in the combined group were significantly better than those of the Lugua polypeptide and BMSCs groups (P <0.05). CONCLUSIONS: BMSC transplantation combined with Lugua polypeptide injection may improve KOA-related cartilage tissue damage in rabbits.

Topical Application of Tranexamic Acid Can Reduce Postoperative Blood Loss in Calcaneal Fractures: A Randomized Controlled Trial.

The traditional lateral "L" approach is common for managing calcaneal fractures with a drawback of significant blood loss. Yet there are no prospective studies on the hemostatic effect of the topical use of tranexamic acid (TXA) in calcaneal fracture surgeries. The purpose of this study was to evaluate the role of topical administration of TXA in reducing postoperative blood loss in calcaneal fractures. Forty participants were randomly distributed into the TXA group (n = 20) and the control group (n = 20). All participants underwent the same surgery via the lateral "L" approach. At the end of the operation, the surgical wound was irrigated with 80 mL 0.5 g/L TXA in the TXA group and 80 mL 0.9% sodium chloride in the control group, followed by the routine use of a drainage tube when closing the incision. Then, 20 mL 0.5 g/L TXA (TXA group) or 20 mL 0.9% sodium chloride solution (control group) was injected retrogradely into the wound through the drainage tube, which was clipped for 30 minutes thereafter. There were no significant differences in the baseline data between the 2 groups (p > .05). There was significantly less blood loss in the first 24 hours and total blood loss postoperation in the TXA group (p < .01). The surgical wounds healed well after surgery in both groups with no complication. We concluded that topical application of TXA in calcaneal fracture surgeries is a safe and useful method that can reduce postoperative blood loss.

Effects of rice straw/wood sawdust addition on the transport/conversion behaviors of heavy metals during the liquefaction of sewage sludge.

Lignocellulosic biomass has been widely introduced into the liquefaction process of sewage sludge (SS) to improve the yield/quality of liquefaction products (bio-oil/biochar). This study explores the effect of adding rice straw (RS) and wood sawdust (WS) on the transport/conversion behaviors of heavy metals (HMs) during the liquefaction of SS. The introduction of lignocellulosic biomass, especially for RS, substantially lowers the total content of HMs in biochar. Most HMs (except Cd) still remain in biochar, although the introduction of RS/WS enhances the transport of HMs into bio-oils. The addition of RS/WS raises the percentage of HMs in active form, but the contents of bioavailable/leachable HMs are not considerably increased and even decreased in some cases, especially when RS is introduced. The overall pollution degree and environmental risk of HMs in biochars are lowered to a certain extent with the addition of RS/WS. Considering that the pollution degree and environmental risk of HMs present in biochars are still at a considerable level, appropriate pollution management measures should be undertaken when using such biochars for agricultural use.

Adsorption isotherms, degradation kinetics, and leaching behaviors of cyanogen and hydrogen cyanide in eight texturally different agricultural soils from China.

Cyanogen (C2N2) is a new and effective alternative soil fumigant to methyl bromide. The effects of soil properties on the fate of C2N2 and its degradation products, including hydrogen cyanide (HCN), are not fully understood. The objectives of this study were to determine the adsorption kinetics, adsorption isotherms, and degradation kinetics of C2N2 and HCN in texturally different soils and evaluate their leaching potentials using soil columns. Eight agricultural soils were collected throughout China: Luvisols (Hebei Province), Phaeozems (Heilongjiang Province), Gleysols (Sichuan Province), Anthrosols (Zhejiang Province), Ferralsols (Jiangxi Province), Lixisols (Hubei Province), Alisols (Shandong Province), and Plinthosols (Hainan Province). The adsorptions of C2N2 and HCN in C2N2-fumigated soils were positively correlated with organic matter and clay contents. For a C2N2 dose of 100 mg kg-1, the adsorptions of C2N2 and HCN were highest in Phaeozems and lowest in Gleysols according to their adsorption coefficients (15.744 and 3.119, respectively). No significant difference in the half-life of C2N2 and HCN was observed between sterilized and unsterilized soils, indicating that abiotic degradation was predominant in the degradation of C2N2 and HCN. After leaching, the residual C2N2, HCN, NH4+-N, and NO3--N concentrations in C2N2-fumigated Phaeozems were highest within 15 cm of the soil surface (30, 20, 19.68, and 10.41 mg kg-1 soil, respectively). The results indicate that C2N2 and HCN have short lifetimes and low leaching potentials in agricultural soils, even under heavy rainfall conditions. The findings demonstrate that C2N2 and HCN resulting from fumigation will not accumulate in the soil and are not likely to contaminate groundwater.

Adsorption-Desorption and Leaching Behaviors of Tetraniliprole in Three Typical Soils of China.

Tetraniliprole (TTP) is a new bisimide-based insecticide. Three typical surface soil samples were collected in farmland across China, including Jiangxi red soil (RS), Shandong yellow brown soil (YBS), and Heilongjiang black soil (BS). Adsorption, desorption and leaching experiments were conducted by using equilibrium oscillation and soil column leaching methods at 25°C ± 1°C. The isothermal adsorption and desorption curves of TTP in the above three soils were in accordance with the Freundlich model. The adsorption/desorption constants (Kads-f/Kdes-f) were 41.96-64.48 and 3.62-43.65, respectively. There is a certain hysteresis in the desorption curve, and the hysteresis coefficient (H) was between 0.14 and 0.89. Besides, the leaching properties of TTP in three soils were different. The leaching of TTP in RS and YBS was easy, while difficult for BS. It is concluded that the different adsorption-desorption ability and leaching ability of TTP in the above three soils was attributed to the distinct contents of organic matter (OM) and cation exchange capacity (CEC) in soil.

[A Study of the Relationship Among Genetic Distances, NIR Spectra Distances, and NIR-Based Identification Model Performance of the Seeds of Maize Iinbred Lines].

This paper explored the relationship among genetic distances, NIR spectra distances and NIR-based identification model performance of the seeds of maize inbred lines. Using 3 groups (total 15 pairs) of maize inbred lines whose genetic distaches are different as experimental materials, we calculates the genetic distance between these seeds with SSR markers and uses Euclidean distance between distributed center points of maize NIR spectrum in the PCA space as the distances of NIR spectrum. BPR method is used to build identification model of inbred lines and the identification accuracy is used as a measure of model identification performance. The results showed that, the correlation of genetic distance and spectra distancesis 0.9868, and it has a correlation of 0.9110 with the identification accuracy, which is highly correlated. This means near-Infrared spectrum of seedscan reflect genetic relationship of maize inbred lines. The smaller the genetic distance, the smaller the distance of spectrum, the poorer ability of model to identify. In practical application, near infrared spectrum analysis technology has the potential to be used to analyze maize inbred genetic relations, contributing much to genetic breeding, identification of species, purity sorting and so on. What's more, when creating a NIR-based identification model, the impact of the maize inbred lines which have closer genetic relationship should be fully considered.

Helical substituted polyacetylene-derived fluorescent microparticles prepared by precipitation polymerization.

This article reports the first fluorescent microparticles (MPs, approximately 600 nm in diameter) constructed using helical substituted polyacetylene and prepared via a precipitation polymerization approach. The MPs judiciously combine this interesting helical conjugated acetylene, fluorescent material and polymeric particles in one entity. The monomer containing a dansyl group undergoes precipitation polymerization in butanone/n-heptane mixed solvent, with (nbd)Rh(+) B(-) (C6 H5 )4 as a catalyst. MPs with a regular morphology are formed in a high yield (>80 wt%). UV-vis spectroscopy demonstrates that the polymer chains making up the MPs adopt helical structures. The MPs show considerable fluorescence emission (λmax , 500 nm; excited at 340 nm). Based on SEM and fluorescence images, the formation mechanism of the MPs is proposed. This methodology opens up new ways to prepare functional microstructured materials derived from substituted polyacetylenes, and may also result in opportunities for new practical applications of polyacetylene and its derivatives.

[Near infrared spectroscopy analysis method of maize hybrid seed purity discrimination].

Near infrared spectroscopy analysis method of discrimination of maize hybrid seed purity was studied with the sample of Nong Hua 101 (NH101) from different origins and years. Spectral acquisition time lasted for 10 months. Using Fourier transform (FT) near infrared spectroscopy instruments, including 23 days in different seasons (divided into five time periods), a total of 920 near infrared diffuse reflectance spectra of single corn grain of those samples were collected. Moving window average, first derivative and vector normalization were used to pretreat all original spectra, principal component analysis (PCA) and linear discriminant analysis (LDA) were applied to reduce data dimensionality, and the discrimination model was established based on biomimetic pattern recognition (BPR) method. Spectral distortion was calibrated by spectra pretreatment, which makes characteristics spatial distribution range of sample spectra set contract. The relative distance between hybrid and female parent increased by nearly 70-fold, and the discrimination model achieved the identification of hybrid and female parent seeds. Through the choice of representative samples, the model's response capacity to the changes in spectral acquisition time, place and environment, etc. was improved. Besides, the model's response capacity to the changes in time and site of seed production was also improved, and the robustness of the model was enhanced. The average correct acceptance rate (CAR) of the test set reached more than 95% while the average correct rejection rate (CRR) of the test set also reached 85%.

Treatment of swine manure by hydrothermal carbonization: The influential effect and preliminary mechanism of surfactants.

Treatment of swine manure by hydrothermal carbonization (HTC) with the aid of different surfactants was first explored in this study. PEG 400 (polyethylene glycol 400) and Tween 80 facilitated the formation of bio-oil. SLS (sodium lignosulfonate) and SDS (sodium dodecyl sulfate) promoted the formation of water-soluble matters/gases. Span 80 enhanced the formation of hydrochar, which resulted in a 50.19 % mass yield, 92.39 % energy yield, and a caloric value of 28.68 MJ/kg. The hydrochar obtained with Span 80 presented a similar combustion performance to raw swine manure and the best pyrolysis performance. The use of Span 80 promoted the transfer of degradation products to hydrochar, especially hydrophobic ester and ketone compounds. Notedly, Span 80 suppressed the synthesis of PAHs during the HTC process, which was reduced to 0.92 mg/kg. Furthermore, the hydrochar produced with Span 80 contained lower contents of heavy metals. On the whole, Span 80 has shown great potential in enhancing the HTC of swine manure. The acting mechanisms of surfactants in the HTC of swine manure included adsorption, dispersion, and electrostatics repulsion.

[Effect of endotracheal intubation and laryngeal mask airway on perioperative respiratory adverse events in children with upper airway infections].

OBJECTIVE: To investigate the effect of endotracheal intubation (TT) or the laryngeal mask airway (LMA) on the incidence of perioperative respiratory adverse events in children with upper respiratory tract infection undergo general anesthesia. METHODS: From November, 2006 to October, 2012 in the Zhuji People's Hospital, 76 children with upper respiratory tract infection approved by hospital ethic committee were randomly divided into 2 groups:group I (n = 36), children were applied with endotracheal intubation during general anesthesia (TT group), while groupII (n = 40), laryngeal mask airway were used (LMA group).Intraoperative mean arterial pressure (MAP), hear rate (HR), pulse oximetry (SPO2), and end-tidal carbon dioxide partial pressure (P ETCO2) were recorded during the surgery. The incidence of adverse events such as hypoxemia, fidgety, sore throat, and laryngospasm were evaluated in resuscitation room.We also assessed the pre- and postoperative symptoms of respiratory tract infection. RESULTS: There was no significant difference in upper respiratory tract infection symptoms between two groups, and the children in both groups have good tolerance to TT or LMA.However, the hemodynamics status in LMA group were more stable than those in TT group after the LMA insertion or removing (P < 0.05). The incidence of hypoxemia, fidgety, sore throat, and laryngospasm were significant lower in LMA group compared with those in TT group (P < 0.05). CONCLUSION: LMA could decrease the incidence of perioperative respiratory adverse events and can be safely used in children with upper respiratory tract infection undergo general anesthesia.

Organic ligands activate the dark formation of hydroxyl radicals (HO•) in surface soil/sediment: Yields, mechanisms, and applications.

Soil is an important sink for various pollutants. Recent findings suggest that soil and sediment would spontaneously form HO• through Fenton or Fenton-like reactions under natural conditions. In this study, the effects and mechanisms of organic ligands (OLs) on the occurrence of HO• in surface soil/sediment were experimentally and computationally examined. Results confirmed that HO• generation was ND-12.92 nmol/g in surface soil/sediment, and the addition of EDTA-2Na would significantly enhance the yields of HO• by 1.4-352 times. Moisture was the decisive factor of soil HO• generation. The release of Fe(II) from solid into the aqueous phase was essential for the stimulation of HO• in EDTA-2Na suspensions. Furthermore, complexation reactions between Fe(II) and OLs would enhance single electron transfer (SET) reactions and the formation of O2•-. Interestingly, for specific OLs, their stimulations on SET and formation of O2•- would depress HO• generation. Provoking HO• generation by OLs could be efficiently used to degrade sulfamethoxazole in rice field sediment. The study provided new knowledge on how commonly synthetic OLs affect the HO• generation in surface soil/sediment, and it additionally shed light on the engineered stimulation of in-situ Fenton reactions in natural soil/sediment.

Removal characteristics of microplastics in sewage flowing through a long-term operation surface flow wetland.

Microplastics (MPs) in sewage pose significant threats to aquatic system. Surface flow wetland (SFW) is a common natural wetland type, and is also used as a cheap and easy-to-build sewage treatment system for small and scattered settlements. However, seasonal variation patterns of MPs in sewage removed by SFW are still limited. Therefore, a field investigation was conducted in an SFW that has been operated for 17 years. The concentration of microplastics in the influent of the SFW (CMPs, in) ranged from 56 ± 6 to 250 ± 14 items L-1. The dominant plastic types were fibers and polyethylene terephthalate (PET). CMPs, in were high in summer and winter, significantly related to the seasonal dressing habits. The removal efficiencies of MPs in SFW were 48.03-92.32 % in different seasons, and the mechanisms of MP removal were different with traditional pollutants. Before flowing out occasionally or by heavy precipitation, MPs were primarily trapped in the SFW and underwent certain oxidation. Simulation experiments demonstrated that 47.5-92.9 % of MPs would be trapped in the SFW, and plants would significantly enhance the trapping capacities. This study sheds light on the seasonal variation characteristics and patterns of MPs in actual sewage, and clarifies the fate of MPs in a long-term operation SFW.

Reduced cadmium(Cd) accumulation in lettuce plants by applying KMnO4 modified water hyacinth biochar.

In this study, water hyacinth was adopted to prepare biochar followed by modification using KMnO4. And the modified biochars were applied in Cd contaminated soil, exploring the effects of water hyacinth biochar on lettuce growth, Cd enrichment, soil enzyme activities and microbial changes by pot experiments. Modified biochar application significantly reduced the Cd accumulation in lettuce shoots and roots. Compared to the control, the application of water hyacinth biochar at 1% rate resulted in significant reduction of Cd contents by 40.7% and 33.7% in the shoots and roots of lettuce. Also, the reduction was 33.3% and 20.8% compared with the application rate of unmodified biochar. With the increase of biochar application, the amount of Cd was absorbed by lettuce shoots and roots showing significant reduction of plant Cd accumulation in response to the biochar application rate. Additionally, the lowest available Cd concentration in soil (1.34 mg kg-1) was obtained with the application of modified biochar at 1% rate, which might be the main reason for the lower Cd concentration in lettuce shoot and root parts. Furthermore, structural analysis showed that Cd was fixed on the modified biochar, in a passivated state, by larger specific surface area, more active sites and more stable covalent binding complexes leading to a strong decrease of the available Cd in the soil. Moreover, it was concluded that the increment of the enzyme activities in the soil was up to 2.51 times significantly following the application of modified water hyacinth biochar with 3% amount. Lastly, 16sRNA sequencing showed that biochar addition may lead to changes of microbial structure and abundance in soil.

Recycling Pomelo Peel Waste in the Form of Hydrochar Obtained by Microwave-Assisted Hydrothermal Carbonization.

Pomelo peel (PP) is a kind of solid waste that is produced in the processing industry of honey pomelo. This study deeply explored the feasibility of recycling PP in the form of hydrochar (HC) by microwave-assisted hydrothermal carbonization (HTC) technology. Under the non-catalytic reaction conditions, the yield of hydrochar initially increased with the rise of reaction temperature (150-210 °C) until it remained relatively stable after 210 °C. Under the CaO-catalytical reaction condition, the yield of hydrochar did not change much at first (150-190 °C) but decreased significantly when the reaction temperature exceeded 190 °C. After the microwave-assisted HTC treatment, the PP-derived HC presented higher aromaticity, carbonization degree, porosity, and caloric value. Compared with raw PP, the nutrients in HC were more stable (conducive to being used as slow-release fertilizer). The application of CaO increased the pH value of HC and effectively promoted the accumulation of phosphorus in HC. The HC produced at 210 °C without any catalyst possessing a high devolatilization ability. Additionally, the HC obtained at 190 °C with CaO as the catalyst presented a high combustion property. In general, PP-derived HC showed great application potential in the field of soil remediation/improvement and solid fuels. This preliminary study would undoubtedly provide some important fundamental understanding of the microwave-assisted HTC of PP.

Pivotal role of water molecules in the photodegradation of pymetrozine: New insights for developing green pesticides.

Photodegradation of the insecticide pymetrozine (PYM) was studied on surface of wax films, and in aqueous and nonaqueous phase. The half-life of PYM on the wax surface was approximately 250 times longer than in water. Scavenging experiments, laser flash photolysis, and spectra analysis indicated the first singlet excited state of PYM (S1 *PYM) to be the most important photoinduced species initiating the photodegradation. Quantum chemistry calculations identified significant molecular torsion and changes in the structure C-CN-N of S1 *PYM, and the absolute charges of the CN atoms increased and the bond strength weakened. Free energy surface analysis, and O18 labeling experiments further confirmed that the mechanism was two-step photoinduced hydrolysis. The first step is the hydrolysis of S1 *PYM at CN upon reaction with 2-3 water molecules (one H2O molecule as the catalyst). The second step is an intramolecular hydrogen transfer coupled with the cleavage of C-N bond and formation of two cyclic products. During the interactions, water molecules experience catalytic activation by transferring protons, while there is a negligible solvent effect. Clarifying the detailed photodegradation mechanisms of PYM is beneficial for the development of green pesticides that are photostable and effective on leaf surfaces, and photolabile and detoxified in the aquatic environment.

Co-liquefaction of Chlorella and soybean straw for production of bio-crude: Effects of reusing aqueous phase as the reaction medium.

Co-liquefaction was combined with hydrothermal liquefaction (HTL) aqueous phase (AP) recirculation to improve the practicality of HTL process. The Chlorella powder (CL), soybean straw (SS), and their mixture (CS) with ratio 1:1 were processed at 300 °C for 20 min, and the AP was recirculated four times. The yield of CS bio-crude was increased (from 24.28% to 31.83%) by co-liquefaction, but remained stable during AP recirculation. By contrast, the yields were increased for CL bio-crude (from 32.40% to 41.19%), SS hydrochar (from 19.55% to 30.88%), and CS hydrochar (from 9.42% to 14.76%) by recirculation. The elemental analysis, chemical composition analysis, functionality analysis, thermogravimetric analysis, and verification experiments (HTL with model AP components) show the N-containing compounds (e.g., amines) in AP were converted into amides (acylation) for CL bio-crude, into N-heterocycles (Maillard reactions) for CS hydrochar, and into Mannich bases for SS hydrochar, which contributed to the increased yield and N content (from 7.27% to 8.82% for CL bio-crude). Furthermore, the O content of CS bio-crude was decreased (from 15.31% to 12.52%) by recirculation, resulted from the conversion of N-heterocyclic ketones into pyrazine derivates. The decreased O content and comprehensive combustibility index (from 0.306 to 0.177) of CS bio-crude indicate the great potential of this craft combination.

Efficient conversion of sewage sludge into hydrochar by microwave-assisted hydrothermal carbonization.

The treatment of sewage sludge (SS) is an environmental problem worldwide. In recent years, hydrothermal carbonization (HTC) of SS for hydrochar (HC) has attracted extensive attention. This study preliminarily explored the microwave-assisted HTC of SS for the first time. Increasing the reaction temperature (150-250 °C) and reaction time (0-120 min) resulted in a decrease in the HC yield, and it gradually increased with the rising solid-liquid ratio (0.03-0.25 g/mL). Compared with raw SS, the HC products possessed higher aromaticity, carbonization degree, porosity, and polarity, and lower content of soluble nutrients (N/P/K) and leachable heavy metals (Cu, Zn, Pb, Cd, Cr, and Ni), indicating a lower risk of nutrient and heavy metal loss. Attention should be paid to the total contents of Zn and Cd in HC exceeded the permitted value for use in cultivated land with edible crops. The use of CaO as a catalyst improved the yield of HC, made the HC and process water (PW) weakly alkaline, and further passivated the heavy metals in the HC. In the case of H3PO4, although the conversion of SS was enhanced (lower content of volatile organic matter in HC), the contents of soluble nutrients (N/P/K) in HC/PW increased, and the migration of Zn and Cd into process water was enhanced. The HCs obtained in this study had poor combustion properties, but higher ignition temperatures than raw SS. PW must be properly treated or recycled because it still contained high contents of organic matter and nutrients. This fundamental study provides basic insights into the microwave-assisted HTC of SS.

Pararectus approach combined with three-dimensional printing for anterior plate fixation of sacral fractures.

BACKGROUND: Surgical treatment of sacral fractures is difficult, both for reduction and stabilization. Traditional surgical reduction and internal fixation require a long duration of operation leading to extra blood loss, extensive tissue damage, and increased risk of post-operation complications. The purpose of this study was to evaluate the feasibility of a minimally invasive technique that could be more effective, more tissue sparing, and lead to less bleeding. We hypothesized that a Pararectus approach for anterior fixation of unstable sacral fractures would be reliable and more advantageous and significantly improve the outcome of sacral fracture repair. METHODS: Twelve patients with unstable sacral fractures were recruited and examined by CT scanning. A 3D model of each sacral fracture was reconstructed. The computer-assisted 3D image of the reduced pelvis was 3D printed for surgery simulation and plate pre-bending. All cases were treated operatively with the anterior anatomical reduction and internal fixation via a minimally invasive Pararectus approach. VAS, Matta, and Majeed scores were used to evaluate outcomes of the operation. RESULTS: Pre-operations were consistent with the actual surgeries in all cases. The pre-bent plates had an anatomical shape specifically fit to the individual pelvis without further adjustment at the time of surgery, and fracture reductions were significantly improved with little invasive tissue damage. The average operation time was 110 min. The intraoperative blood loss and incision length averaged 695 ml and 6.7 cm, respectively. A high percentage of all cases achieved a diaplasis with an excellent or good score according to the Matta and Majeed standards (83.33% and 91.67%, respectively).All patients achieved clinical healing with an average healing time of 8 weeks. CONCLUSION: 3D printing-assisted anterior fixation of unstable sacral fractures via a minimally invasive Pararectus approach is feasible. This new surgical strategy minimizes trauma damage and bleeding and produces satisfactory reduction and therapeutic efficacy.

A comparison study of applying natural iron minerals and zero-valent metals as Fenton-like catalysts for the removal of imidacloprid.

Natural iron minerals and zero-valent metals have been widely tested as catalysts for the Fenton-like process, but the systematical comparison study about their catalytic performance was rarely conducted, and the risk of the secondary pollution of toxic heavy metals was still not uncertain. In this paper, a comparison study of applying pyrite, ilmenite, vanadium titano-magnetite (VTM), zero-valent iron (ZVI), and zero-valent copper (ZVC) as Fenton-like catalysts for the removal of imidacloprid was performed. The results showed that ZVI exhibited the highest activity among the recyclable solid catalysts with a removal rate of 96.8% at initial pH 3 using 10.78 mmol/L H2O2, due to iron corrosive dissolution. Vanadium titano-magnetite (VTM) exhibited the best activity at first use among tested minerals but with low reusability. Pyrite with stable morphology showed a medium but sustainable ability to degrade imidacloprid, achieving a removal rate of 10.5% in the fifth use. The reaction much favored the acidic condition of initial pH around 2 or 3. Meanwhile, there was a significant positive correlation between removal efficiency and dissolved Fe or Cu concentration. Pyrite was considered to be a promising catalyst in Fenton-like reaction. It was suggested that the system proceeded predominantly through a homogeneous route via dissolved Fe or Cu ions. Except ZVC and VTM, other tested catalysts showed the low possibility of causing secondary pollution of toxic metals in the application of Fenton-like process.

Speciation of Main Nutrients (N/P/K) in Hydrochars Produced from the Hydrothermal Carbonization of Swine Manure under Different Reaction Temperatures.

Hydrothermal carbonization (HTC) has been proved to be a promising technology for swine manure (SM) treatment. Currently, there is a lack of systematic understanding of the transformation characteristics of nutrient speciation in the HTC of SM. In this study, the speciation of the main nutrients (N/P/K) in SM-derived hydrochar produced at different reaction temperatures (200-280 °C) was investigated. The recovery of P (61.0-67.1%) in hydrochars was significantly higher than that of N (23.0-39.8%) and K (25.5-30.0%), and the increase in reaction temperature promoted the recovery of P and reduced the recovery of N. After the HTC treatment, the percentage of soluble/available P was reduced from 61.6% in raw SM to 4.0-23.9% in hydrochars, while that of moderately labile/slow-release P was improved from 29.2% in raw SM feedstock to 65.5-82.7%. An obvious reduction was also found in the amounts of available N (from 51.3% in raw SM feedstock to 33.0-40.5% in hydrochars). The percentages of slow-release N and residual N in hydrochars produced at 240 °C reached the maximum and minimum values (46.4% and 18.9%), respectively. A total of 49.5-58.3% of K retained in hydrochars was residual (invalid) potassium. From the perspective of the mobility and availability of N, P and K only, it was suggested that the HTC of SM should be carried out at 220-240 °C. Compared with the original SM, it is safer and more effective to use the SM-derived hydrochar as an organic fertilizer.