Environmental sustainability assessment of a new food waste anaerobic digestion and pyrolysis hybridization system.

This research conducted an environmental life cycle assessment (LCA) to evaluate an anaerobic digestion-co-pyrolysis (ADCo-Py) system in which pyrolysis was added to traditional food waste (FW) anaerobic digestion (AD) systems to treat the solid fraction and impurities separated from FW. The solid fraction, including impurities such as wooden chopsticks, plastics, eggshells, and bones, is usually incinerated, while pyrolysis can be a viable alternative to optimize FW treatment. The environmental impact of ADCo-Py was compared with stand-alone AD, pyrolysis, and ADCo-INC (AD with incineration of separated solids). The results indicated that both ADCo-Py (-1.726 kg CO2-Eq/kgFW) and ADCo-INC (-1.535 kg CO2-Eq/kgFW) outperform stand-alone AD (-0.855 kg CO2-Eq/kgFW) and pyrolysis (-0.181 kg CO2-Eq/kgFW) in mitigating global warming potential (GWP). Additionally, pretreatments were found to have the most significant influence on GWP, ecotoxicity potential (ETP), and acidification potential (AP). The two-step pretreatment in ADCo-Py, including the separation of solids and drying, significantly improved the environmental sustainability of the system when compared with standalone pyrolysis.

Experimental study and techno-economic analysis of co-processing system for treatment of food waste with various impurities.

The study assessed a co-processing system segregating food waste (FW) with different impurities into liquid (slurry) and solid fractions and treated using anaerobic digestion (AD) and pyrolysis (Py), respectively, which is defined as ADCo-Py. Biomethane potential tests showed higher methane yield from the FW slurry fraction (572.88 mL/gVSFW) compared to the whole FW (294.37 mL/gVSFW). Pyrolyzing the FW solid fraction reduced nitrogen compounds in bio-oil by 62 % compared to the whole FW. The energy balance and economic feasibility of ADCo-Py were compared with stand-alone AD, Py, and AD integrated with incineration (ADCo-INC). While all systems required extra energy, stand-alone Py and ADCo-INC needed 3.8 and 2.8 times more energy than ADCo-Py, respectively. Techno-economic analysis favored ADCo-Py, with a net present value (NPV) of $15 million and an internal rate of return (IRR) of 34 %. These findings highlighted FW separation as a promising approach, aligning with energy and economic goals in sustainable FW management.

Evolutions of dissolved organic matter and disinfection by-products formation in source water during UV-LED (275 nm)/chlorine process.

Ultraviolet light-emitting diode (UV-LED) is a promising option for the traditional low-pressure UV lamp, but the evolutions of DOM composition, the formation of disinfection by-products (DBPs) and their toxicity need further study in raw water during UV-LED/chlorine process. In UV-LED (275 nm)/chlorine process, two-dimensional correlation spectroscopy (2DCOS) analysis on synchronous fluorescence and UV-vis spectra indicated the protein-like fractions responded faster than the humic-like components, the reactive sequence of peaks for DOM followed the order: 340 nm→240 nm→410 nm→205 nm→290 nm. Compared to chlorination for 30 mins, the UV-LED/chlorine process enhanced the degradation efficiency of three fluorescent components (humic-like, tryptophan-like, tyrosine-like) by 5.1%-46.1%, and the formation of carbonaceous DBPs (C-DBPs) significantly reduced by 43.8% while the formation of nitrogenous DBPs (N-DBPs) increased by 27.3%. The concentrations of C-DBPs increased by 17.8% whereas that of N-DBPs reduced by 30.4% in 24 h post-chlorination. The concentrations of brominated DBPs increased by 17.2% during UV-LED/chlorine process, and further increased by 18.5% in 24 h post-chlorination. According to the results of principal component analysis, the non-fluorescent components of DOM might be important precursors in the formation of haloketones, haloacetonitriles and halonitromethanes during UV-LED/chlorine process. Unlike chlorine treatment, the reaction of DOM in UV-LED/chlorine treatment generated fewer unknown DBPs. Compared with chlorination, the cytotoxicity of C-DBPs reduced but the cytotoxicity of both N-DBPs and Br-DBPs increased during UV-LED/chlorine process. Dichloroacetonitrile had the highest cytotoxicity, followed by monobromoacetic acid, bromochloroacetonitrile and trichloroacetic acid during 30 mins of UV-LED/chlorine process. Therefore, besides N-DBPs, the more toxic Br-DBPs formation in bromide-containing water is also not negligible in the practical applications of UV-LED (275 nm)/chlorine process.

Clinical features and treatment effect of HIV-associated immune thrombocytopenia-single center Ten-Years data summary.

Thrombocytopenia represents one of the most prevalent hematologic complications observed in patients infected with the human immunodeficiency virus (HIV). In this study, we sought to analyze the clinical characteristics and treatment outcomes of patients with coexisting HIV and thrombocytopenia. Specifically, we retrospectively examined the medical records of 45 patients diagnosed with HIV/AIDS and thrombocytopenia at the Yunnan Infectious Diseases Specialist Hospital between January 2010 and December 2020, all of whom received highly active antiretroviral therapy (HAART) with/without glucocorticoids. The median follow-up period was 79 days, ranging between 14 and 368 days, the total platelet count was higher after receiving treatment than before (Z = -5.662, P < .001). Among the cohort, 27 patients (60.0%) responded to treatment, with 12 patients (44.44%) experiencing relapse during the follow-up period. The response rate (80.00%) of newly diagnosed ITP were significantly higher than of persistent ITP (28.57%) and chronic ITP (38.46%) (\x 2 = 9.560, P = .008) and the relapse rate of the newly diagnosed ITP (30.00%) was significantly lower than the persistent ITP and chronic ITP (100.00%, 80.00%) (\x2 = 6.750, P = .034). Notably, we found that the number of CD4+ T cells, duration of HIV infection, selection of HAART and type of glucocorticoids administered displayed no statistically significant effect on platelet count, treatment response, or relapse rate. However, we observed a significant decrease in platelet count in hepatitis C virus-positive individuals coinfected with HIV compared to those with HIV alone (Z = -2.855, P = .003). Our findings suggest that patients diagnosed with HIV and thrombocytopenia exhibit a low response rate to treatment and have an increased likelihood of relapse.

Improving the Electron Transport Performance of TiO2 Film by Regulating TiCl4 Post-Treatment for High-Efficiency Carbon-Based Perovskite Solar Cells.

Titanium oxide (TiO2 ) has been widely used as an electron transport layer (ETL) in perovskite solar cells (PSCs). Typically, TiCl4 post-treatment is indispensable for modifying the surfaces of TiO2 ETL to improve the electron transport performance. However, it is challenging to produce the preferred anatase phase-dominated TiO2 by the TiCl4 post-treatment due to the higher thermodynamic stability of the rutile phase. In this work, a mild continuous pH control strategy for effectively regulating the hydrolysis process of TiCl4 post-treatment is proposed. As the weak organic base, urea has been demonstrated can maintain a moderate pH decrease during the hydrolysis process of TiCl4 while keeping the hydrolysis process relatively mild due to the ultra-weak alkalinity. The improved pH environment is beneficial for the formation of anatase TiO2 . Consequently, a uniform anatase-dominated TiO2 surface layer is formed on the mesoporous TiO2 , resulting in reduced defect density and superior band energy level. The interfacial charge recombination is effectively suppressed, and the charge extraction efficiency is improved simultaneously in the fabricated solar cells. The efficiency of the fabricated carbon electrode-based PSCs (C-PSCs) is improved from 16.63% to 18.08%, which is the highest for C-PSCs based on wide-bandgap perovskites.

Satellite Navigation Spoofing Interference Detection and Direction Finding Based on Array Antenna.

Satellite navigation signals are feeble when they reach the ground, so they are vulnerable to attacks from outside interference signals. By emitting spoofing interference signals similar to real satellite signals, spoofing interference can make receivers give wrong navigation, position, and time information, and it is challenging to detect. This seriously affects the safe use of GNSS; therefore, it is essential to identify spoofing interference signals quickly and accurately. In our study, we proposed a novel six-array spoofing-interference-monitoring array antenna, which achieved the detection and identification of spoofing interference sources by monitoring the relevant peaks and combining an airspace-trapping algorithm. Moreover, we quickly accomplished our search for the whole circumferential ambiguity by using long- and short-baseline algorithms, which can realize the high-precision detection of spoofing interference sources. To verify this method's accuracy, we conducted outdoor real experiments using a special spoofing interference source, and our experimental results show that our proposed array antenna's directional accuracy for spoofing interference signals is kept within 2°, showing high spoofing interference direction-finding capability.

How Family Living Arrangements and Migration Distances Shape the Settlement Intentions of Rural Migrant Workers in China.

Rural migrant workers and their families will decide the future of China's urbanization. Using data from the "China Migrants Dynamic Survey and Hundreds of Villages Investigation" carried out in 2018, we examine whether and how family living arrangements and migration distances shape rural migrant workers' settlement intentions in urban areas. In general, rural migrant workers' settlement intention is shown to be weak. However, individuals with children are more likely to have a stronger intention to settle permanently in urban areas. Among geographical factors, geospatial distance exerts a negative influence on migrant parents' settlement intention when the interaction effect of family living arrangements and migration distances is considered. Migrant families are increasingly concentrated in cities near their hometowns with a low entry barrier that allows them to gain access to better amenities. Socio-economic factors, especially disposable income, human resources, and housing conditions, play significant roles in migrant parents' settlement intention. The age and hometown region of migrant parents are also closely related to their intentions to settle in urban areas. Potential channels for the management of urbanization policy are also explored.

Effectiveness and mechanism for the simultaneous adsorption of Pb(II), Cd(II) and As(III) by animal-derived biochar/ferrihydrite composite.

The emerging animal-derived biochar (AB) has shown potential for mitigating the contamination of cationic heavy metals, but has no affinity to oxyanionic metals. In this study, we developed an AB/ferrihydrite composite with a AB/Fe mass ratio of 4.0 (ABF-4) for the simultaneous adsorption of cationic Pb(II)/Cd(II) and anionic As(III). ABF-4 is a type of hydroxyapatite-rich biochar coated with nanoscale iron hydroxide aggregates. The adsorption of Pb(II), Cd(II), and As(III) on ABF-4 were 2.64, 1.55, and 0.48 mmol/g, and were 135%, 150%, and 4500% higher than those of pure AB, respectively. The enhanced adsorption of Pb(II) and Cd(II) by ABF-4 is partially due to the increase in surface area and micropores. The nano-sized ferrihydrite on ABF might help form surface complexation with As(III) and oxidize As(III) to As(V). In multimetal systems, Pb(II) and Cd(II) can promote As(III) adsorption due to the formation of NaPb4(AsO4)3 precipitate and the ternary complex of arsenite and cadmium with ABF-4, whereas Cd(II) adsorption might be inhibited because of the surface coverage of Pb5(PO4)3Cl precipitate on ABF-4. However, the coexistence of Pb in soils does not influence the immobilization of Cd. The amendment of ABF-4 can considerably decrease the availability of Pb, Cd, and As in soils from Pb-Zn smelting sites. Hence, ABF-4 is a promising multifunctional material for the potential immobilization of multicomponent heavy metals.

Recyclable nitrogen-doped biochar via low-temperature pyrolysis for enhanced lead(II) removal.

Facile and low-cost preparation are essential in the conversation of agricultural waste into biochar. In this work, nitrogen-doped biochar (NBC-350-0.1) was prepared by thermal decomposition of urea (urea/biochar = 0.1:1 mass ratio) at a low temperature of 350 °C. NBC-350-0.1 showed good performance for Pb(II) removal with the maximum adsorption capacity of 130.87 mg g-1 at 25 °C, which was five times that of pristine biochar (BC). Adsorption kinetics, isotherms and thermodynamics studies indicated that the adsorption of Pb(II) by NBC-350-0.1 or BC was the homogeneous monolayer adsorption with chemical action as the rate-limiting step, and was accompanied by spontaneous endothermic. Further analysis showed that the removal of Pb(II) on NBC-350-0.1 and BC depended on the complexation with unsaturated carbon bonds and ion exchange with Ca(II). Moreover, graphitic- and pyridinic-N in NBC-350-0.1 exerted a key part in the adsorption of Pb(II). NBC-350-0.1 regenerated by NaOH exhibited excellent recycling performance keeping the original removal efficiency at 84% after five cycles. In addition, this N doping method is suitable for improving the performance of coffee grounds, sawdust, and bagasse biochar. These results would provide an idea for obtaining recyclable N-doped biochar to treat the Pb(II) polluted wastewater.

Moving-Distance-Minimized PSO for Mobile Robot Swarm.

Particle swarm optimizer (PSO) and mobile robot swarm are two typical swarm techniques. Many applications emerge separately along both of them while the similarity between them is rarely considered. When a solution space is a certain region in reality, a robot swarm can replace a particle swarm to explore the optimal solution by performing PSO. In this way, a mobile robot swarm should be able to efficiently explore an area just like the particle swarm and uninterruptedly work even under the shortage of robots or in the case of unexpected failure of robots. Furthermore, the moving distances of robots are highly constrained because energy and time can be costly. Inspired by such requirements, this article proposes a moving-distance-minimized PSO (MPSO) for a mobile robot swarm to minimize the total moving distance of its robots while performing optimization. The distances between the current robot positions and the particle ones in the next generation are utilized to derive paths for robots such that the total distance that robots move is minimized, hence minimizing the energy and time for a robot swarm to locate the optima. Experiments on 28 CEC2013 benchmark functions show the advantage of the proposed method over the standard PSO. By adopting the given algorithm, the moving distance can be reduced by more than 66% and the makespan can be reduced by nearly 70% while offering the same optimization effects.

Study on preparation and application of a multifunctional microspheric soil conditioner based on Arabic gum, gelatin, chitosan and ß-cyclodextrin.

All kinds of soil conditioners have been used to improve soil quality. The application of many traditional soil conditioners was limited by single performance. In this study, a novel multifunctional microspheric soil conditioner was prepared based on Arabic gum, gelatin, chitosan and ß-cyclodextrin. Arabic gum and gelatin (AG-GL) microspheric carriers, which could load ferrous sulfate (FS), were synthesized via complex coagulation method. The AG-GL(FS) microspheres were covered by chitosan quaternary ammonium salt (CQAS) through single coagulation method. And ß-cyclodextrin (ß-CD) was used as the outermost shell to improve chemical stability of the soil conditioner by saturated solution method. Finally, the novel multifunctional microspheric soil conditioner AG-GL/CQAS/ß-CD-FS was obtained and characterized by Fourier transform infrared spectroscopy, thermogravimetric analyzer, polarizing microscope, scanning electron microscope and particle size analyzer. The novel soil conditioner shows good nutrient slowly-releasing, water retention, heavy metal ions adsorption and antibacterial performances with the particle size of 14-17 µm and high thermal decomposition temperature, which has the potential application in improving soil quality.

A critical review on energy recovery and non-hazardous disposal of oily sludge from petroleum industry by pyrolysis.

This review systematically reports the pyrolysis of oily sludge (OS) from petroleum industry in regards to its dual features of the energy recovery potential and the environmental risks. The petroleum hydrocarbons are the nonbiodegradable fractions in OS that possess hazardous properties, i.e. ignitability and toxicity. Besides, complicated hazardous elements (i.e. N, S and Cl) and heavy metals inherently existing in OS further aggravate the environmental risks. However, the high oil content and heating value of OS contribute to its huge energy resource potential. Considering the energy demand and the environmental pressure, the ultimate purposes of the OS management are to enhance the oil recovery efficiency to minimize the oil content as well as to stabilize the hazardous elements and heavy metals into the solid residue. Among various OS management technologies, pyrolysis is the most suitable approach to reach both targets. In this review paper, the pyrolysis principle, the kinetics and the product distribution in three-phases are discussed firstly. Then the effects of operating parameters of the pyrolysis process on the quality and the application potential of the three-phase products, as well as the hazardous element distribution are discussed. To further solve the dominant concerns, such as the oil content in the solid residue, the pyrolytic oil quality and the migration of hazardous elements and heavy metals, the potentials of the catalytic pyrolysis and the co-pyrolysis with additives are also summarized. Also, the typical pyrolysis reactors are then presented. From the perspective of the energy efficiency and the non-hazardous disposal, the integrated technology combining the pyrolysis and the combustion for the OS management is recommended. Finally, the remaining challenges of OS pyrolysis encountered in the research and the industrial application are discussed and the related outlooks are itemized.

Hazardous elements flow during pyrolysis of oily sludge.

Oily sludge (OS) is a hazardous waste and pyrolysis is a promising technology to achieve energy recovery and non-hazardous disposal simultaneously. However, the distribution of hazardous elements, including N/S/Cl and heavy metals, in pyrolytic products possibly causes secondary pollution. This study conducted a systematic research on hazardous elements flow during OS pyrolysis under variant temperature. Results showed that N/S/Cl in OS were distributed 44.77-15.51 wt%, 83.29-80.22 wt%, and 78.59-73.41 wt% into the solid residues after pyrolysis, respectively. Elevating pyrolysis temperature facilitated more N/S/Cl flowing into pyrolytic oil and gas. The macromolecular N-/S-/Cl-containing compounds, including amides, amines, nitriles, sulfonates, chloroalkanes, etc., were widely distributed in pyrolytic oil and gas products. The micromolecular N-/S-/Cl-containing pollutants released between 200 and 400 °C included HCN, NH3, NOx, H2S, CH4S, CS2, SO2, and HCl, which originated from the decomposition of the amine N, organic sulfide and sulfone-S, and inorganic Cl, respectively. The main pollutants released at above 400 °C included NH3, HCN, NOx, CS2, and SO2, which were derived from the decomposition of heterocyclic N and inorganic pyritic-S and sulfate-S. Moreover, the solid residues intercepted more than 60.0 wt% of total heavy metals, which should be concerned in the future.

Pristine and iron-engineered animal- and plant-derived biochars enhanced bacterial abundance and immobilized arsenic and lead in a contaminated soil.

In this study, typical animal- and plant-derived biochars derived from pig carcass (PB) and green waste (GWB), and their iron-engineered products (Fe-PB and Fe-GWB) were added at the dose of 3% (w/w) to an acidic (pH = 5.8) soil, and incubated to test their efficacy in improving soil quality and immobilizing arsenic (As = 141.3 mg kg-1) and lead (Pb = 736.2 mg kg-1). Soil properties, microbial activities, and the geochemical fractions and potential availabilities of As and Pb were determined in the non-treated (control) and biochar-treated soil. Modification of PB (pH = 10.6) and GWB (pH = 9.3) with Fe caused a decrease in their pH to 4.4 and 3.4, respectively. The application of PB and GWB significantly increased soil pH, while Fe-PB and Fe-GWB decreased soil pH, as compared to the control. Application of Fe-GWB and Fe-PB decreased the NH4H2PO4-extractable As by 32.8 and 35.9%, which was more effective than addition of GWB and PB. However, PB and GWB were more effective than Fe-PB and Fe-GWB in Pb immobilization. Compared to the control, the DTPA-extractable Pb decreased by 20.6 and 21.7%, respectively, following PB and GWB application. Both biochars, particularly PB significantly increased the 16S rRNA bacterial gene copy numbers, indicating that biochar amendments enhanced the bacterial abundance, implying an alleviation of As and Pb bio-toxicity to soil bacteria. The results demonstrated that pristine pig carcass and green waste biochars were more effective in immobilizing Pb, while their Fe-engineered biochars were more effective in As immobilization in co-contaminated soils.

Sorption of diethyl phthalate and cadmium by pig carcass and green waste-derived biochars under single and binary systems.

Potentially toxic elements (PTEs) and phthalic acid esters (PAEs) often coexist in contaminated soils. Their co-existence may affect the mutual sorption behavior, and thereby influence their bioavailability and fate in soils. To our best knowledge, the impacts of plant-and animal-derived biochar on the competitive sorption-desorption of PTEs and PAEs in soils with different organic carbon content have not been studied up to date. Therefore, in this study, batch sorption-desorption experiments were conducted to investigate the influence of biochars derived from pig carcass and Platanus orientalis branches on the mono- and competitive sorption of cadmium (Cd2+) and diethyl phthalate (DEP) in soils with high (HS) and low (LS) organic carbon content. The DEP sorption was well described by Freundlich isotherm model, while Cd2+ sorption fitted better with the Langmuir isotherm model. Application of both biochars enhanced soil sorption of DEP, which increased as the application doses increased. The HS showed a stronger affinity to both DEP and Cd2+ than the LS. In the LS, the pig carcass biochar (PB) addition was more effective to increase the sorption capacity of Cd2+ and DEP and to reduce their desorption than woody biochar (WB) treatments. Moreover, the co-existing of Cd2+ could reduce the sorption of DEP, especially in the LS. The presence of DEP enhanced Cd2+ sorption in LS treated by both biochars, but the sorption of Cd2+ was suppressed with DEP addition in the PB-amended HS. In conclusion, the soil sorption capacity of DEP and Cd2+ was affected by biochar type, application dose and soil organic carbon content. The reciprocal effect between DEP and Cd2+ was also a crucial factor influencing their sorption/desorption by biochar. Therefore, PB and WB, especially PB, can be used for metal/DEP immobilization due to enhanced sorption. This approach is applicable for future remediation of soils contaminated by PTEs and PAEs.

Desflurane protects against liver ischemia/reperfusion injury via regulating miR-135b-5p.

BACKGROUND: A number of anesthetics have protective effect against ischemia-reperfusion (I/R) injury, including desflurane. But the function and molecular mechanism of desflurane in liver I/R injury have not been fully understood. The aim of this study was to investigate the effect of desflurane on liver I/R injury and further investigated the molecular mechanisms involving in miR-135b-5p. METHODS: The models of liver I/R injury in rats were established, and received desflurane treatment throughout the injury. Serum alanine transaminase (ALT) and aspartate transaminase (AST) were measured and compared between groups. H/R-induced cell model in L02 was established, and were treated with desflurane before hypoxia. Quantitative real-time polymerase chain reaction was performed to determine the expression of miR-135b-5p in different groups. The cell apoptosis was detected using flow cytometry assay. Western blot was used for the measurement of protein levels. RESULTS: I/R significantly increased serum levels of ALT and AST in rats, which were reversed by desflurane treatment. Desflurane also significantly attenuated the increase of cell apoptosis induced by I/R in both vivo and vitro. MiR-135b-5p significantly reversed the protective effect of desflurane against liver I/R injury. Additionally, Janus protein tyrosine kinase (JAK)2 was shown to be a target gene of miR-135b-5p, and miR-135b-5p overexpression significantly decreased the protein levels of p-JAK2, JAK2, p-STAT3. CONCLUSION: Desflurane attenuated liver I/R injury through regulating miR-135b-5p, and JAK2 was the target gene of mIR-135b-5p. These findings provide references for further development of therapeutic strategies in liver injury.

ZnCl2 enabled synthesis of activated carbons from ion-exchange resin for efficient removal of Cu2+ ions from water via capacitive deionization.

Capacitive deionization (CDI) is a promising method to remove metal contaminants in water. Herein, we report on the preparation of activated carbon from cation-exchange resin by introducing ZnCl2 via ion exchange followed by heat treatment and CO2 activation, which is evaluated for removal of Cu2+ in water via CDI technology. The results have shown that both the heat treatment and the CO2 activation are helpful to tune the pore structure of the activated carbons in terms of ions adsorption and transportation. The activated carbon prepared by heat treatment at 600 °C and CO2 activation at 750 °C, named as AC-600-750, has the highest specific surface area of 1162 m2 g-1 and a specific capacitance of 247.4 F g-1 at 50 mV-1, with a Cu2+ adsorption capacity of 77.8 mg g-1 at 1.2 V in 50 mg L-1 CuCl2 solution that is much higher than that of the commercial activated carbon. The electrosorption of Cu2+ ions over activated carbon follows a monolayer adsorption scheme, of which the kinetic can be well explained by pseudo-first-order kinetic model. The resin-based activated carbons are of potential as an electrode material for efficient removal of heavy metal from contaminated water by CDI process.

Animal carcass- and wood-derived biochars improved nutrient bioavailability, enzyme activity, and plant growth in metal-phthalic acid ester co-contaminated soils: A trial for reclamation and improvement of degraded soils.

Reclamation of degraded soils such as those with low organic carbon content and soils co-contaminated with toxic elements and phthalic acid esters (PAEs) is of great concern. Little is known about the efficiency of plant- and animal-derived biochars for improving plant growth and physicochemical and biological properties of co-contaminated soils, particularly under low content of organic matter. Hence, a pot trial was carried out by growing pak choi (Brassica chinensis L.) to assess the influence of different doses (0, 0.5, 1, 2, and 4%) of animal (pig carcass) and wood (Platanus orientalis) derived biochars on soil properties, nutrient availabilities, plant growth, and soil enzyme activities in two soils containing low (LOC) and high (HOC) organic carbon contents and co-contaminated with di-(2-ethylhexyl) phthalic acid (DEHP) and cadmium (Cd). Biochar applications improved pH, salinity, carbon content, and cation exchange capacity of both soils. Addition of biochars significantly increased the bioavailability and uptake of phosphorus and potassium in the plants in both soils with greater effects from pig biochar than wood biochar. Biochar additions also significantly enhanced urease, sucrase, and catalase activities, but suppressed acid phosphatase activity in both soils. The impact of pig biochar was stronger on urease and acid phosphatase, while the wood biochar was more effective with sucrase and catalase activities. The biomass yield of pak choi was significantly increased after biochar addition to both soils, especially in 2% pig biochar treatment in the LOC soil. The positive response of soil enzymes activities and plant growth for biochar addition to the Cd and DEHP co-contaminated soils indicate that both biochars, particularly the pig biochar can mitigate the risk of these pollutants and prove to be eco-friendly and low-cost amendments for reclaiming these degraded soils.

Lead competition alters the zinc adsorption mechanism on animal-derived biochar.

In this study, the adsorption behaviors and mechanisms of Pb(II) and Zn(II) by animal-derived biochar (ADB) in single and binary metal systems were comparatively investigated. ADB contains considerable amounts of Ca/P components and is mainly composed of hydroxyapatite (HAP), which plays an important role in the adsorption of Pb(II) and Zn(II). The maximum adsorption capacities of Pb(II) and Zn(II) on ADB were in the order of Zn(II)-single (3.23 mmol g-1) > Pb(II)-single (2.74 mmol g-1) ≈ Pb(II)-binary (2.71 mmol g-1) > Zn(II)-binary (2.31 mmol g-1). In the single metal system, approximately 99.9% of the adsorbed Pb(II) existed as Pb5(PO4)3Cl, while the dominant adsorption mechanism of Zn(II) was cation exchange, followed by precipitation, accounting for 78.0%-80.6% and 19.4%-21.5% of the adsorption capacity, respectively. These findings were verified by X-ray diffraction refinement, X-ray photoelectron spectroscopy, metal speciation modeling, and Ca(II) exchange experiment. In the binary metal system, the proportion and form of Pb(II) precipitate remained unchanged. However, the binding of Zn(II) to ADB was completely dependent on the cation exchange with Ca(II), and no remarkable Zn(II) precipitation was observed. Phosphate released from HAP preferentially precipitated with Pb(II) than with Zn(II) when they coexisted. Consequently, Pb(II) competition may alter the Zn(II) adsorption mechanism on ADB. Nonetheless, ADB could serve as an efficient biochar for the simultaneous immobilization of Pb(II) and Zn(II) via different mechanisms.

Hybrid ash/biochar biocomposites as soil amendments for the alleviation of cadmium accumulation by Oryza sativa L. in a contaminated paddy field.

A novel ash/biochar (A/B) biocomposite composed of 90% biomass bottom ash from agroforestry biomass direct-fired power plants, 5% animal-derived biochar from carcass pyrolysis, and 5% bentonite as an adhesive was amended in cadmium (Cd)-polluted paddy soil to alleviate cadmium accumulation by Oryza sativa L. Ash increased the soil pH and contributed exogenous available silicon. Biochar with high Ca/P components played an important role in soil cadmium immobilization. A 1-year field experiment with consecutive rice growing seasons (early and late rice) was conducted in Xiangtan, China, to examine the effects of A/B amendment in Cd-contaminated paddy soil. The A/B biocomposite was amended into soil through one-time addition at three application rates (1, 5, and 10 kg/m2). When A/B amendment was ≥5 kg/m2, the soil pH increased from 4.11 to more than 6. The available silicon content in the soil even increased by 22.9 times. For early rice soil, the CaCl2-extractable Cd(II) and toxicity characteristic leaching procedure (TCLP)-extractable Cd(II) decreased by 77.9%-96.1% and 52.4%-70.7%, respectively. A/B remarkably reduced Cd accumulation in rice organs, and this observation was related to A/B treatment rates. Ash and biochar contributed to the inhibition of Cd accumulation in rice organs and Cd translocation from roots to stems. The Cd concentrations in brown rice decreased to 0.11 and 0.12 mg/kg in early and late rice, respectively, and these values were lower than the national food safety standard limit value of China (0.2 mg/kg).