Changes in microbial communities during high-rate microbial selenate reduction in an up-flow anaerobic fluidized bed reactor.

Biological fluidized bed reactor (FBR) is a promising treatment option for removing selenium oxyanions from wastewater by converting them into elemental selenium. The process can achieve high rates and be efficiently operated at low hydraulic retention times (HRT). However, the effects of HRT on the changes in microbial community in the FBR process have not been previously explored. In this study, dynamic changes of microbial communities both on biofilm carrier and in suspension of a selenate-reducing FBR were explored at various HRTs (0.3-120 h). Based on partial 16S rRNA gene sequencing of the microbial communities, alpha diversity of microbial communities in suspension rather than in the biofilm were impacted by low HRTs (0.3 h-3 h). Members from genera Geobacter, Geoalkalibacter, and Geovibrio were the main selenate-reducing bacteria on carrier throughout the FBR process. Genus Geobacter was dominant in FBR carrier at HRT of 24 h-120 h, whereas Geoalkalibacter and Geovibrio dominated at low HRT of 0.3 h-6 h. Suspended microbial communities detected in the FBR effluent were more sensitive to HRT changes than that in biofilm. "Shock loading" at HRT of 0.3 h had a great impact on microbial community compositions both in the biofilm and effluent. Reactor operation in batch mode and long HRT of 24 h helped recover the community from "shock loading" and improved selenite reduction and ethanol oxidation. Redundancy analysis revealed that HRT, influent pH and selenate loading were key operational parameters impacting both the FBR performance and the composition of microbial communities associated with both the FBR carrier and effluent. Overall, the microbial communities in FBR biofilm flexibly responded to the changes of HRT and showed resilience to the temporary shock loading, enabling efficient selenate removal.

Thoracic sarcopenia was a poor prognostic predictor in patients receiving immunotherapy retain-->for advanced non-small-cell retain-->lung cancer.

RATIONALE AND OBJECTIVES: Sarcopenia, as measured at the level of the third lumbar (L3) has been shown to predict the survival of cancer patients. However, many patients with advanced non-small cell lung cancer (NSCLC) do not undergo routine abdominal imaging. The objective of this study was to investigate the association of thoracic sarcopenia with survival outcomes among patients who underwent immunotherapy for NSCLC. MATERIALS AND METHODS: In this retrospective study, patients who initiated immunotherapy for advanced NSCLC from 2019 to 2022 were enrolled. and detailed patient data were collected. Cross sectional skeletal muscle area was calculated at the fifth thoracic vertebra (T5) on pretreatment chest computed tomography (CT) scan. Gender-specific lowest quartile values was used to define sarcopenia. The risk factors were analyzed using Cox analyses. The log-rank test and the random survival forest (RSF) were used to compare progression free survival (PFS). The model's performance was assessed using calibration curve and the receiver operating characteristic curve (ROC). RESULTS: A total of 242 patients was included (discovery cohort n = 194, validation cohort n = 48). In the discovery cohort, patients with sarcopenia exhibited significantly poorer PFS (p < 0.001) than patients without sarcopenia. Univariate cox regression revealed that sarcopenia, lung cancer stage, body mass index, smoking status, and neutrophil-to-lymphocyte ratio were predictors of poor PFS. A RSF model was constructed based on the aforementioned parameters, to evaluate the model's efficacy, the ROC curve was utilized. with an area under the curve for predicting 6-month PFS of 0.68 and for 12-month PFS of 0.69. The prediction models for survival outcomes built by the discovery cohort showed similar performance in the validation cohort. CONCLUSION: Sarcopenia at T5 is independent prognostic factors in patients who received immunotherapy for advanced NSCLC.

Phase transformation of schwertmannite in paddy soil under different water management regimes and its impact on the migration of arsenic in soil.

Schwertmannite (Sch) holds a great promise as an iron material for remediating Arsenic (As)-contaminated paddy soils, due to its extremely high immobilization capacities for both arsenate [As(V)] and arsenite [As(III)]. However, there is still limited knowledge on the mineral phase transformation of this metastable iron-oxyhydroxysulfate mineral in paddy soils, particularly under different water management regimes including aerobic, intermittent flooding, and continuous flooding, and how its phase transformation impacts the migration of As in paddy soils. In this study, a membrane coated with schwertmannite was first developed to directly reflect the phase transformation of bulk schwertmannite applied to paddy soils. A soil incubation experiment was then conducted to investigate the mineral phase transformation of schwertmannite in paddy soils under different water management regimes and its impact on the migration of As in paddy soil. Our findings revealed that schwertmannite can persist in the paddy soil for 90 days in the aerobic group, whereas in the continuous flooding and intermittent flooding groups, schwertmannite transformed into goethite, with the degree or rate of mineral phase transformation being 5% Sch >1% Sch > control. These results indicated that water management practices and the amount of schwertmannite applied were the primary factors determining the occurrence and degree of mineral transformation of schwertmannite in paddy soil. Moreover, despite undergoing phase transformation, schwertmannite still significantly reduced the porewater As (As(III) and As(V)), and facilitated the transfer of non-specifically adsorbed As (F1) and specifically adsorbed As (F2) to amorphous iron oxide-bound As (F3), effectively reducing the bioavailability of soil As. These findings contribute to a better understanding of the mineralogical transformation of schwertmannite in paddy soils and the impact of mineral phase transformation on the retention of As in soil, which carry important implications for the application of schwertmannite in remediating As-contaminated paddy soils.

Improving bio-conditioning dewatering performance of food waste anaerobic digestate at low ambient temperatures by heating treatment.

Food waste anaerobic digestate (FWAD) containing high concentrations of contaminants must be purified or recycled. Bio-conditioning dewatering followed by activated sludge process (BDAS) has emerged as a promising technology for treating FWAD. However, the bio-conditioning dewatering as a pivotal step of BDAS is often negatively affected by low ambient temperatures often occurred in winter. This study investigated the role of heating FWAD in improving the bio-conditioning dewatering performance of FWAD. Batch experiments demonstrated that the bio-conditioning dewatering efficiency increased with temperature rise. Notably, due to the low energy consumption, 50°C was considered to be the most appropriate heating treatment temperature, realizing a drastic reduction of specific resistance to filtration (SRF) of bio-conditioned FWAD from initial 1.24 × 1012 m/kg in the control at a ambient temperature of 10°C to 5.42 × 1011 m/kg and a saving of 25% in bio-conditioning reagents cost. The results of the pilot-scale and large-scale experiments revealed that heating treatment made the bio-conditioning dewatering more stable regardless of the fluctuation of ambient temperature in practical engineering. The decrease in the viscosity of bio-conditioned FWAD and the enhancement in microbial fermentation liquor flocculation capacity through heating treatment played pivotal roles in improving the bio-conditioning dewatering performance of FWAD. This work provides a cost-effective strategy to achieve efficient bio-conditioning dewatering at a relatively low ambient temperature, which was helpful in the engineering application of the novel BDAS process in wastewater treatment.

Effects of food waste hydrolysate as an external carbon source on defoaming in wastewater treatment with activated sludge process.

The activated sludge process is the most widely used technology for treating municipal wastewater. However, thick foam often occurs in activated sludge process. Here, we reported for the first time the effect of food waste hydrolysate (FWH) as an external carbon source on defoaming in activated sludge process. The study found that FWH was effective in defoaming at a wide dose range of 50-1600 mg/L total solids, as exhibiting that the foaming tendency of FWH-added foam mixed liquor was reduced to 0 mL-foam/mL-air·min from initial 0.171 mL-foam/mL-air·min in the control without adding FWH with 100 % of defoaming efficiency. Fatty acids, oils, and solid particles in FWH jointly contributed to the deformation. Among these factors, the concentration of long-chain unsaturated fatty acids was mainly responsible for the defoaming. This work provides a cost-effective strategy to solve the foaming problem in activated sludge process as well as providing external carbon sources.

Enhancing sludge dewaterability in sequential bioleaching: Degradation of dissolved organic matter (DOM) by filamentous fungus Mucor sp. ZG-3 and the influence of energy source.

This study aimed to enhance sludge dewatering through sequential bioleaching, employing the filamentous fungus Mucor sp. ZG-3 and the iron-oxidizing bacterium Acidithiobacillus ferrooxidans LX5. The mechanism by which Mucor sp. ZG-3 alleviates sludge dissolved organic matter (DOM) inhibition of A. ferrooxidans LX5 was investigated, and the optimal addition of energy source for enhanced sludge dewaterability during sequential bioleaching was determined. Sludge dissolved organic carbon (DOC) decreased to 272 mg/L with a 65.2% reduction by Mucor sp. ZG-3 in 3 days, and the degraded fraction of sludge DOM was mainly low-molecular-weight DOM (L-DOM) which inhibited the oxidization of Fe2+ by A. ferrooxidans LX5. By degrading significant inhibitory low-molecular-weight organic acids, Mucor sp. ZG-3 alleviated DOM inhibition of A. ferrooxidans LX5. In the sequential bioleaching process, the optimal concentration of FeSO4·7H2O for A. ferrooxidans LX5 was 4 g/L, resulting in the minimum specific resistance to filtration (SRF) of 2.60×1011 m/kg, 40.0% lower than that in the conventional bioleaching process with 10 g/L energy source. Moreover, the sequential bioleaching process increased the sludge zeta potential (from -31.8 to -9.47 mV) and median particle size (d50) of the sludge particle (from 17.90 to 27.44 µm), contributing to enhanced sludge dewaterability. Inoculation of Mucor sp. ZG-3 during the bioleaching process reduced the demand for energy sources by A. ferrooxidans LX5 while improving sludge dewaterability performance.

Innexin hemichannel activation by Microplitis bicoloratus ecSOD monopolymer reduces ROS.

The extracellular superoxide dismutases (ecSODs) secreted by Microplitis bicoloratus reduce the reactive oxygen species (ROS) stimulated by the Microplitis bicoloratus bracovirus. Here, we demonstrate that the bacterial transferase hexapeptide (hexapep) motif and bacterial-immunoglobulin-like (BIg-like) domain of ecSODs bind to the cell membrane and transiently open hemichannels, facilitating ROS reductions. RNAi-mediated ecSOD silencing in vivo elevated ROS in host hemocytes, impairing parasitoid larva development. In vitro, the ecSOD-monopolymer needed to be membrane bound to open hemichannels. Furthermore, the hexapep motif in the beta-sandwich of ecSOD49 and ecSOD58, and BIg-like domain in the signal peptides of ecSOD67 were required for cell membrane binding. Hexapep motif and BIg-like domain deletions induced ecSODs loss of adhesion and ROS reduction failure. The hexapep motif and BIg-like domain mediated ecSOD binding via upregulating innexins and stabilizing the opened hemichannels. Our findings reveal a mechanism through which ecSOD reduces ROS, which may aid in developing anti-redox therapy.

Efficient co-stabilization of arsenic and cadmium in farmland soil by schwertmannite under long-term flooding-drying condition.

Simultaneously stabilizing of arsenic (As) and cadmium (Cd) in co-contaminated soil presents substantial challenges due to their contrasting chemical properties. Schwertmannite (Sch) is recognized as a potent adsorbent for As pollution, with alkali modification showing promising results in the simultaneous immobilization of both As and Cd. This study systematically investigated the long-term stabilization efficacy of alkali-modified Sch in Cd-As co-contaminated farmland soil over a 200-day flooding-drying period. The results revealed that As showed significant mobility in flooded conditions, whereas Cd exhibited increased soil availability under drying phases. The addition of Sch did not affect the trends in soil pH and Eh fluctuations; nonetheless, it led to an augmentation in the levels of amorphous iron oxides and SO42- concentration in soil pore water. At a dosage of 0.5% Sch, there was a notable decrease in the mobility and soil availability of As and Cd under both flooding (34.5% and 53.6% at Day 50) and drying conditions (27.0% and 29.4% at Day 130), primarily promoting the transformation of labile metal(loid) fraction into amorphous iron oxide-bound forms. Throughout the flooding-drying treatment period, Sch maintained stable mineral morphology and mineralogical phase, highlighting its long-term stabilization effect. The findings of this study emphasize the promising application of Sch-based soil remediation agents in mitigating the challenges arising from As-Cd co-contamination. Further research is warranted to explore their application in real farmland settings and their impact on the uptake of toxic metal(loid)s by plants.

Pivotal role of intracellular oxidation by HOCl in simultaneously removing antibiotic resistance genes and enhancing dewaterability during conditioning of sewage sludge using Fe2+/Ca(ClO)2.

Pre-acidification has been shown to be crucial in attenuating antibiotic resistance genes (ARGs) during the conditioning of sewage sludge. However, it is of great significance to develop alternative conditioning approaches that can effectively eliminate sludge-borne ARGs without relying on pre-acidification. This is due to the high investment costs and operational complexities associated with sludge pre-acidification. In this study, the effects of Fe2+/Ca(ClO)2 conditioning treatment on the enhancement of sludge dewaterability and the removal of ARGs were compared with other conditioning technologies. The dose effect and the associated mechanisms were also investigated. The findings revealed that Fe2+/Ca(ClO)2 conditioning treatment had the highest potential, even surpassing Fenton treatment with pre-acidification, in terms of eliminating the total ARGs. Moreover, the effectiveness of the treatment was found to be dose-dependent. This study also identified that the •OH radical reacted with extracellular polymeric substance (EPS) and extracellular ARGs, and the HOCl, the production of which was positively correlated with the dose of Fe2+/Ca(ClO)2, could infiltrate the EPS layer and diffuse into the cell of sludge flocs, inducing the oxidation of intracellular ARGs. Furthermore, this study observed a significant decrease in the predicted hosts of ARGs and MGEs in sludge conditioned with Fe2+/Ca(ClO)2, accompanied by a significant downregulation of metabolic pathways associated with ARG propagation, thereby contributing to the attenuation of sludge-borne ARGs. Based on these findings, it can be concluded that Fe2+/Ca(ClO)2 conditioning treatment holds great potential for the removal of sludge-borne ARGs while also enhancing sludge dewaterability, which mainly relies on the intracellular oxidation by HOCl.

Insight into performance of nitrogen removal enhanced by adding lactic acid-rich food waste fermentation liquid as carbon source in municipal wastewater treatment.

Lactic acid-rich fermentation liquid (LAFL) of food waste is found to act as a promising alternative carbon source for nitrogen removal in wastewater treatment. Here, LAFL was employed to investigate its impacts on nitrogen removal during raw municipal wastewater treatment with a comparison to sodium acetate (NaAc). Results indicated that nitrogen removals were comparable when incorporated with LAFL and NaAc (92.89 % v.s. 91.23 %). Unlike the utilization of NaAc, using LAFL could avoid suppressing the relative abundance of the nitrification genes and thus pose a negative risk to nitrogen removal during prolonged operation. The introduction of LAFL increased the stability and robustness of the functional microbial community and effectively reduced excess activated sludge (AS) generation by 109 % compared to NaAc addition, consequently enhancing nitrogen removal but diminishing the treatment cost. In general, LAFL exhibits prospective engineering application potentials and economic advantages in improving nitrogen removal by AS process.

Aeration pre-treatment role in improving the performance of bio-conditioning dewatering of food waste anaerobic digestate.

Bio-conditioning dewatering followed by activated sludge process (BDAS) is a promising technology for purifying food waste anaerobic digestate (FWAD). However, the bio-conditioning dewatering efficiency is often affected by FWAD properties and ambient temperature. Here, we firstly reported that aeration pre-treatment of FWAD played an important role in improving the bio-conditioning dewatering performance of FWAD. The study found that the accumulated carbonate (CO32-) in FWAD severely affected the flocculation of Fe-containing flocculant formed in microbial fermentation liquor due to the competitive consumption of the flocculant by CO32-. The capillary suction time (CST) and specific resistance to filtration (SRF) of the bio-conditioned FWAD increased from initial 77.8 s and 2.0 × 1012 m/kg to 122.7 s and 3.4 × 1012 m/kg, respectively, within 1 day of aeration. Prolonged aeration pre-treatment of FWAD could reduce its CO32- concentration and total alkalinity. Additionally, the aeration pre-treatment simultaneously decreased the proportion of macromolecular organic matter that hindered dewatering and the content of total solids (TS) and hydrophilic protein-like substances in FWAD. After 20 days of aeration followed by bio-conditioning, the CST and SRF reduced to final 36.5 s and 2.3 × 1011 m/kg, respectively, indicating a substantial improvement in dewatering performance. Successive forced aeration combined with the addition of CaCl2 to eliminate adverse factors mainly CO32- was a feasible and cost-effective strategy to realize bio-conditioning dewatering of FWAD in less than 2 days and a lower reagents dose of bio-conditioning, which was helpful in the engineering application of the novel BDAS process for FWAD purification.

A novel approach for purifying food waste anaerobic digestate through bio-conditioning dewatering followed by activated sludge process: A case study.

Although anaerobic digestion is the mainstream technology for treating food waste (FW), the high pollutant concentration in the resultant food waste anaerobic digestate (FWAD) often poses challenges for the subsequent biochemical treatment such as activated sludge process. In this study, taking a typical FW treatment plant as an example, we analyzed the reasons behind the difficulties in treating FWAD and tested a novel process called as bio-conditioning dewatering followed by activated sludge process (BDAS) to purify FWAD. Results showed that high concentrations of suspended solids (SS) (16439 ± 475 mg/L), chemical oxygen demand (COD) (24642 ± 1301 mg/L), and ammonium nitrogen (NH4+-N) (2641 ± 52 mg/L) were main factors affecting the purification efficiency of FWAD by the conventional activated sludge process. By implementing bio-conditioning dewatering for solid-liquid separation, near 100% of SS and total phosphorus (TP), 90% of COD, 38% of total nitrogen (TN), and 37% of NH4+-N in the digestate could be effectively removed or recovered, consequently generating the transparent filtrate with relatively low pollution load and dry sludge cake (<60% of moisture content). Furthermore, after ammonia stripping and biochemical treatment, the effluent met the relevant discharge standards regulated by China, with the concentrations of COD, TN, NH4+-N, and TP ranging from 151 to 405, 10-56, 0.9-31, and 0.4-0.8 mg/L, respectively. This proposed BDAS approach exhibited stable performance and low operating costs, offering a promising solution to purify FWAD in practical engineering and simultaneously realize resource recovery.

Enhanced dewatering extent of sludge by Fe3O4-driven heterogeneous Fenton.

Homogeneous Fenton (Fe2+/H2O2) serves as a high-efficiency conditioning method for sludge dewatering due to the generation of strong oxidizing hydroxyl radicals (OH). However, high dose of ferric salts produces iron-rich dewatered sludge and decrease sludge organic matters, which will not be conducive to the subsequent disposal and reutilization. Considering advantages of Fe3O4 as heterogeneous Fenton catalyst, Fe3O4-activated H2O2 (Fe3O4 + H2O2) in this study was adopted to improve sludge deep-dewatering. Reduction efficiency of the bound water (71.3 %) after Fe3O4 + H2O2 treatment (after a reaction time of 30 min) were much higher than those in the Fe2++H2O2 treatment. Especially, the moisture content of treated sludge cake by Fe3O4 + H2O2 remarkably decreased from 86.4 % to 61.3 %. Improvement mechanism of sludge dewatering after Fe3O4 + H2O2 treatment mainly included electrostatic neutralization, reactive radical oxidation, and skeleton building by analysis of contribution factors. The generation of H+ in acidification could neutralize the negatively charged compounds to promote sludge hydrophobicity. Meanwhile reactive radicals generated from Fe3O4 + H2O2 destroyed sludge extracellular polymeric substances and cell structure to release intracellular water. Furthermore, Fe3O4 as a skeleton builder could reconstruct destructive sludge flocs and form new dewatering channels. Finally, low Fe leaching content and recoverability of Fe3O4 effectively will decrease environmental implication.

Dyeing sludge-derived biochar for efficient removal of antibiotic from water.

Adsorption is one of the most effective methods for ecotoxic antibiotics removal, while developing high-performance adsorbents with excellent adsorption capacity is indispensable. As the unavoidable by-product of wastewater, sewage sludge has dual properties of pollution and resources. In this study, dyeing sludge waste was converted to biochar by KOH activation and pyrolysis, and used as an efficient adsorbent for aqueous antibiotics removal. The optimized dyeing sludge-derived biochar (KSC-8) has excellent specific surface area (1178.4 m2/g) and the adsorption capacity for tetracycline (TC) could reach up to 1081.3 mg/g, which is four and five times higher than those without activation, respectively. The PSO (pseudo-second-order) kinetic model and the Langmuir isotherm model fitted better to the experimental data. The obtained KSC-8 has stabilized adsorption capacity for long-term fixed-bed experiments, and maintained 86.35% TC removal efficiency after five adsorption-regeneration cycles. The adsorption mechanism involves electrostatic attraction, hydrogen bonding, π-π interactions and pore filling. This work is a green and eco-friendly way as converting the waste to treat waste in aiming of simultaneous removal of antibiotics and resource recovery of dyeing sludge.

Simulating immunosuppressive mechanism of Microplitis bicoloratus bracovirus coordinately fights Spodoptera frugiperda.

Parasitoid wasps control pests via a precise attack leading to the death of the pest. However, parasitoid larvae exhibit self-protection strategies against bracovirus-induced reactive oxygen species impairment. This has a detrimental effect on pest control. Here, we report a strategy for simulating Microplitis bicoloratus bracovirus using Mix-T dsRNA targeting 14 genes associated with transcription, translation, cell-cell communication, and humoral signaling pathways in the host, and from wasp extracellular superoxide dismutases. We implemented either one-time feeding to the younger instar larvae or spraying once on the corn leaves, to effectively control the invading pest Spodoptera frugiperda. This highlights the conserved principle of "biological pest control," as elucidated by the triple interaction of parasitoid-bracovirus-host in a cooperation strategy of bracovirus against its pest host.

Sheep Face Detection Based on an Improved RetinaFace Algorithm.

The accurate breeding of individual sheep has shown outstanding effectiveness in food quality tracing, prevention of fake insurance claims, etc., for which sheep identification is the key to guaranteeing its high performance. As a promising solution, sheep identification based on sheep face detection has shown potential effectiveness in recent studies. Unfortunately, the performance of sheep face detection has still been a challenge due to diverse background illumination, sheep face angles and scales, etc. In this paper, an effective and lightweight sheep face detection method based on an improved RetinaFace algorithm is proposed. In order to achieve an accurate and real-time detection of sheep faces on actual sheep farms, the original RetinaFace algorithm is improved in two main aspects. Firstly, to accelerate the speed of multi-scale sheep face feature extraction, an improved MobileNetV3-large with a switchable atrous convolution is optimally used as the backbone network of the proposed algorithm. Secondly, the channel and spatial attention modules are added into the original detector module to highlight important facial features of the sheep. This helps obtain more discriminative sheep face features to mitigate against the challenges of diverse face angles and scale in sheep. The experimental results on our collected real-world scenarios have shown that the proposed method outperforms others with an F1score of 95.25%, an average precision of 96.00%, a model size of 13.20 M, an average processing time of 26.83 ms, and a parameter of 3.20 M.

Schwertmannite-based heterogeneous Fenton for enhancing sludge dewaterability over a wide pH range.

Fe-based Fenton technology is commonly used to enhance sludge dewaterability, but it requires subsequent neutralization, resulting in excessive chemical consumption. In this study, we investigated the feasibility of using schwertmannite-composited Fe3O4 (Sch/Fe3O4) as a heterogeneous Fenton catalyst to enhance sludge dewaterability without the need for pH adjustment. A high reduction efficiency of sludge specific resistance to filtration (94.4%), moisture content (11.4%) and bound water (45.5%) after Sch/Fe3O4 +H2O2 treatment at initial pH 7.5 were obtained, suggesting that Sch/Fe3O4 +H2O2 posed good dehydration performance without any acidification. SO42- and H+ generation in Sch/Fe3O4 system played an important role in sludge pH decrease, which facilitated sludge cell lysis, intracellular water release, and provided a suitable pH for Fenton reaction. Reactive species (•OH, •O2-, and 1O2) from Sch/Fe3O4 +H2O2 could effectively destroy sludge EPS, releasing more bound water. Additionally, the negatively charged compounds were neutralized by dissolved Fe2+/Fe3+. Sch/Fe3O4, as a skeleton builder, rearranged the dissociative sludge flocs to improve the incompressibility and permeability of sludge cake. Finally, sludge treated with Sch/Fe3O4 +H2O2 achieved organic matters reserve, heavy metals reduction, further benefiting the final disposal.

Promoting dewatering efficiency of sludge by bioleaching coupling chemical flocculation.

In recent years, bioleaching has emerged as a cost-effective technology for enhancing the dewaterability of sludge. However, the lengthy treatment time involved in sludge bioleaching processes limits daily treatment capacity for sludge. Here, a novel approach was developed through a short time of sludge bioleaching with A. ferrooxidans LX5 (A. f) and A. thiooxidans TS6 (A. t) followed by polyferric sulfate (PFS) flocculation (A. f + A. t + PFS). After 12.5 h of the A. f + A. t + PFS treatment (30% A. f, 10% A. t, 40 mg/g DS S0, 60 mg/g DS FeSO4•7H2O, and 120 mg/g DS PFS), the reduction efficiency of specific resistance to filtration (SRF) and sludge cake moisture content reached 94.0% and 11.6%, respectively, which were comparable to the results achieved through 24 h of completed bioleaching treatment. In pilot-scale applications, the mechanical dewatering performance was notably improved following A. f + A. t + PFS treatment, with the low moisture content of the treated sludge cake (∼59.2%). This study provides new insights into the A. f + A. t + PFS process and holds potential for developing efficient and promising sludge dewatering strategies in engineering application.

Elemental sulfur redox bioconversion for selective recovery of phosphorus from Fe/Al-bound phosphate-rich anaerobically digested sludge: Sulfur oxidation or sulfur reduction?

The biological oxidation of elemental sulfur (S0) to sulfate and the reduction of S0 to sulfide provide a potential route for extracting and reclaiming phosphorus (P) from anaerobically digested sludge (ADS). However, the treatment performance, stability, and cost-effectiveness of the two opposing bioprocesses based on S° for selective P recovery from ADS remain unclear. This study aimed to compare the roles of S0-oxidizing bacteria (S0OB) and S0-reducing bacteria (S0RB) in liberating insoluble P from ADS through single-batch and consecutive multibatch experiments. Changes in P speciation in the sludge during the biological extraction processes were analyzed by using complementary sequential extraction and P X-ray absorption near-edge spectroscopy. Results showed that S0OB treatment extracted more phosphate from the sludge compared with S0RB treatment, but it also released a considerable amount of metal cations (e.g., heavy metals, Mg2+, Al3+, Ca2+) and negatively affected sludge dewaterability due to intense sludge acidification and cell lysis. At pH 1.2, the S0OB treatment released 92.9% of P from the sludge, with the dissolution of HAP, Fe-PO4, Mg3(PO4)2, and P-fehrrihy contributing 26.8%, 22.1%, 12.8%, and 10.5%, respectively. The S0RB treatment released 63.6% of P from the sludge at pH 7.0, with negligible dissolution of metal cations, thereby avoiding costly purification of the extract and alkali neutralization for pH adjustment. This treatment involved the replacement of phosphates bounded with Fe-PO4 (FePO4 and P-fehrrihy) and Al-PO4 (P-Alumina and AlPO4) with biogenic sulfides, with contributions of 72.7%, and 20.9%, respectively. Consecutive bioprocesses for P extraction were achieved by recirculating the treated sludge. Both S0OB and S0RB treatments did not affect the extent of sludge dewatering but considerably weakened the dewatering rate. The S0OB-treated sludge exhibited prolonged filtration time (from 3010 s to 9150 s) and expressing time (from 795 s to 4690 s) during compression dewatering. After removing metal cations using cation exchange resin (CER) and neutralizing using NaOH, a vivianite product Fe3(PO4)2·8H2O (purity: 84%) was harvested from the S0OB-treated extract through precipitation with FeSO4·7H2O. By contrast, a vivianite product Fe3(PO4)2·8H2O (purity: 81%) was directly obtained from the S0RB-treated extract through precipitation with FeSO4·7H2O. Ultimately, 79.8 and 57.9wt% of P were recovered from ADS through S0OB extraction-CER purification-alkali neutralization-vivianite crystallization, and S0RB extraction-vivianite crystallization, respectively. Collectively, biological S0 reduction is more applicable than biological S0 oxidation for selectively reclaiming P from Fe/Al-associated phosphate-rich ADS due to better cost-effectiveness and process simplicity. These findings are of significance for developing sludge management strategies to improve P reclamation with minimal process inputs.

Five New Glycoside Constituents from the Roots of Gentiana crassicaulis Duthie ex Burk.

Three undescribed glycoside constituents, macrophyllosides E-G and a pair of iridoid glycosides genticrasides A/B, together with eleven known glycoside compounds were isolated from the roots of Gentiana crassicaulis Duthie ex Burk. Their structures were identified by means of spectra analysis and data comparison with previous literatures. Interestingly, the glucose moieties in macrophylloside E and F possess free anomeric hydroxy groups. Genticrasides A/B, identified as a pair of iridoid originated lactones, have not been reported from Gentianaceae family up to now. The anti-inflammatory effects of selected compounds were also evaluated through the nitric oxide (NO) production inhibition in lipopolysaccharides (LPS)-induced RAW264.7 macrophage cells. In which, macrophyllosides G and D showed NO inhibitory activities with rates of 76.14±4.02 % and 52.44±8.29 % at 100 µg/mL.