Enhancing nitrogen removal in constructed wetlands: The role of influent substrate concentrations in integrated vertical-flow systems.

Recent advancements in constructed wetlands (CWs) have highlighted the imperative of enhancing nitrogen (N) removal efficiency. However, the variability in influent substrate concentrations presents a challenge in optimizing N removal strategies due to its impact on removal efficiency and mechanisms. Here we show the interplay between influent substrate concentration and N removal processes within integrated vertical-flow constructed wetlands (IVFCWs), using wastewaters enriched with NO3--N and NH4+-N at varying carbon to nitrogen (C/N) ratios (1, 3, and 6). In the NO3--N enriched systems, a positive correlation was observed between the C/N ratio and total nitrogen (TN) removal efficiency, which markedly increased from 13.46 ± 2.23% to 87.00 ± 2.37% as the C/N ratio escalated from 1 to 6. Conversely, in NH4+-N enriched systems, TN removal efficiencies in the A-6 setup (33.69 ± 4.83%) were marginally 1.25 to 1.29 times higher than those in A-3 and A-1 systems, attributed to constraints in dissolved oxygen (DO) levels and alkalinity. Microbial community analysis and metabolic pathway assessment revealed that anaerobic denitrification, microbial N assimilation, and dissimilatory nitrate reduction to ammonium (DNRA) predominated in NO3--N systems with higher C/N ratios (C/N ≥ 3). In contrast, aerobic denitrification and microbial N assimilation were the primary pathways in NH4+-N systems and low C/N NO3--N systems. A mass balance approach indicated denitrification and microbial N assimilation contributed 4.12-47.12% and 8.51-38.96% in NO3--N systems, respectively, and 0.55-17.35% and 7.83-33.55% in NH4+-N systems to TN removal. To enhance N removal, strategies for NO3--N dominated systems should address carbon source limitations and electron competition between denitrification and DNRA processes, while NH4+-N dominated systems require optimization of carbon utilization pathways, and ensuring adequate DO and alkalinity supply.

Nonlinear model predictive control-Cross-coupling control with deep neural network feedforward for multi-hydraulic system synchronization control.

This paper studies a multi-hydraulic system (MHS) synchronization control algorithm. Firstly, a general nonlinear asymmetric MHS state space entirety model is established and subsequently the model form is simplified by nonlinear feedback linearization. Secondly, an entirety model-type solution is proposed, integrating a nonlinear model predictive control (NMPC) algorithm with a cross-coupling control (CCC) algorithm. Furthermore, a novel disturbance compensator based on the system's inverse model is introduced to effectively handle disturbances, encompassing unmodeled errors and noise. The proposed innovative controller, known as nonlinear model predictive control-cross-coupling control with deep neural network feedforward (NMPC-CCC-DNNF), is designed to minimize synchronization errors and counteract the impact of disturbances. The stability of the control system is rigorously demonstrated. Finally, simulation results underscore the efficacy of the NMPC-CCC-DNNF controller, showcasing a remarkable 60.8% reduction in synchronization root mean square error (RMSE) compared to other controllers, reaching up to 91.1% in various simulations. These results affirm the superior control performance achieved by the NMPC-CCC-DNNF controller.

Performance and mechanism of pilot-scale carbon fibers enhanced ecological floating beds for urban tail water treatment in optimized ecological floating beds water surface coverage.

A pilot-scale carbon fibers enhanced ecological floating beds (CF-EFBs) was constructed. Compared to EFBs without carbon fibers enhancement, CF-EFBs have the better removal of total inorganic nitrogen (TIN), total phosphorus (TP), and chemical oxygen demand (COD), the removal efficiencies were 3.19, 3.49, and 2.74 times higher than EFBs. Throughout the pilot test (under three different coverage rates), the concentrations of COD, TIN and TP of effluent were 18.11 ± 4.52 mgL-1, 1.95 ± 0.92 mgL-1 and 0.13 ± 0.08 mgL-1. Meanwhile, the average removal of TIN, TP and COD from tailwater was 0.96 gm-2d-1, 0.07 gm-2d-1 and 2.37 gm-2d-1 respectively. When the coverage was 30 %, the CF-EFBs had better nitrogen removal effectiveness (TIN purification ability of 1.49 gm-2d-1). The enrichment of denitrifying bacteria, such as Aridibacter, Nitrospira, Povalibacter, and Phaeodactylibacter increased denitrification efficiency. These results verified the feasibility of CF-EFBs in tailwater treatment at pilot-scale, which was of great significance for the practical application of CF-EFBs.

Evaluating the stability and performance of a novel core-shell ZVI@C-montmorillonite particle for anaerobic treatment of chloramphenicol wastewater.

ZVI@C-MP is a novel composite particle consisting of zero-valent iron (ZVI) enclosed within a carbon shell. The purpose of this composite material is to enhance the anaerobic treatment of wastewater containing chloramphenicol (CAP). This approach aims to address the initial challenge of excessive corrosion experienced by ZVI, followed by its subsequent passivation and inactivation. ZVI@C-MP was synthesized through a hydrothermal process and calcination, with montmorillonite as binder, it exhibits stability, iron-carbon microelectrolysis (ICME) properties, and strong adsorption for CAP. Its ICME actions include releasing iron ions (0.70 mg/L) and COD (11.3 mg/L), generating hydrogen (3.82%), and raising the pH from 6.30 to 7.71. With minimal structural changes, it achieved release equilibrium. ZVI@C-MP boasts high removal efficiency of CAP (98.96%) by adsorption, attributed to surface characteristics (surface area: 167.985 m2/g; pore volume: 0.248 cm3/g). The addition of ZVI@C-MP increases COD removal (10.16%), methane production (72.86%), and reduces extracellular polymeric substances (EPS) from 70.58 to 52.72 mg/g MLVSS. It reduces microbial by-products and toxic effects, enhancing CAP biodegradation and microbial metabolic activity. ZVI@C-MP's electrical conductivity and biocompatibility bolster functional flora for interspecies electron transfer. It's a novel approach to antibiotic wastewater treatment.

Three-dimensional graphene aerogel mitigated the toxic impact of chloramphenicol wastewater on microorganisms in an EGSB reactor.

Anaerobic treatment of chloramphenicol wastewater holds significant promise due to its potential for bioenergy generation. However, the high concentration of organic matter and residual toxic substances in the wastewater severely inhibit the activity of microorganisms. In this study, a three-dimensional graphene aerogel (GA), as a conductive material with high specific surface area (114.942 m2 g-1) and pore volume (0.352 cm3 g-1), was synthesized and its role in the efficiency and related mechanism for EGSB reactor to treat chloramphenicol wastewater was verified. The results indicated that synergy effects of GA for Chemical Oxygen Demand (COD) removal (increased by 8.17 %), chloramphenicol (CAP) removal (increased by 4.43 %) and methane production (increased by 70.29 %). Furthermore, GA increased the average particle size of anaerobic granular sludge (AGS) and promoted AGS to secrete more redox active substances. Microbial community analysis revealed that GA increased the relative abundance of functional bacteria and archaea, specifically Syntrophomonas, Geobacter, Methanothrix, and Methanolinea. These microbial species can participate in direct interspecific electron transfer (DIET). This research serves as a theoretical foundation for the application of GA in mitigating the toxic impact of refractory organic substances, such as antibiotics, on microorganisms during anaerobic treatment processes.

Oxygen-Doped Red Carbon Nitride: Enhanced Charge Separation and Light Absorption for Robust CO2 Photoreduction.

Utilizing artificial photosynthesis for the conversion of CO2 into value-added fuels has been recognized as a promising strategy for the ever-increasing energy crisis and the greenhouse effect. Herein, the element doping engineering of red spherical g-C3N4 having oxygen bonded with compositional carbon (C-O-C) for CO2 photoreduction has been explored to address this challenge. The C-O bond was formed by hydrothermal treatment with dicyandiamide and 1,3,5-trichlorotriazine. The experimental and DFT results displayed the optimum oxygen substitution sites and demonstrated that the oxygen doping greatly improved the light utilization efficiency, CO2 affinity, and charge carrier transfer, which enhanced photoreduction efficiency of CO2. The evolution rates of CO (47.2 µmol g-1) and CH4 (9.1 µmol g-1) using O-CN were much higher than that of bulk-CN without a cocatalyst. The main reason was the contribution of the O 2p orbital to the conduction band (CB) and valence band of O-CN, which effectively reduced the electron mass, facilitating electron/hole separation and enhancing its fluidity. Furthermore, the Fermi level also shifted to the bottom of the CB, leading to higher electron density, which further improved the CO2 reduction ability. Our study marks an important step for developing high-performance photocatalysts for reduction of CO2.

Effects of groundwater depth on groundwater recharge and soybean growth dynamics in Northeast China Plain.

To explore the groundwater recharge rate and soybean growth dynamics under different groundwater depths, we conducted a field experiment with four groundwater depth treatments (1 m, D1; 2 m, D2; 3 m, D3; 4 m, D4) through the groundwater simulation system in 2021 and 2022 and explored the relationships between groundwater depth and groundwater recharge, irrigation, growth dynamics of soybean plants, and yield. We used the Logistic regression model to simulate the dynamics of soybean growth indices, including plant height, leaf area index, and dry matter accumulation. The results showed that compared with D1 treatment, the amount of groundwater recharge under D2, D3, and D4 treatments decreased by 81.1%, 96.8%, 97.5% and 80.7%, 96.7%, 97.3% in the two years, respectively. The groundwater in D1 treatment could meet water needs of soybean throughout the whole growth period, except that irrigation was needed in the sowing stage. The amount of irrigation under D1 treatment was decreased by 91.7%, 93.0%, 94.2%, and 90.9%, 92.9%, 94.0% in the two years, respectively, compared with D2, D3, D4 treatments. Among the four treatments, D1 treatment took the shortest time for entering the rapid growth stage and reach the maximum growth rate, which had the highest maximum growth rate. At the mature stage of soybean, the dry matter distribution ratio of stem in D1 treatment was the highest. D1 treatment promoted the translocation of post-flowering assimilates in soybean, and its post-flowering assimilate contribution to seeds increased by 15.5%, 16.2%, 32.6% and 45.5%, 48.7%, 63.3% in the two years, respectively, compared with D2, D3, D4 treatments. D1 treatment had the highest plant height, leaf area index, and dry matter accumulation, follo-wed by D4 treatment, while D3 treatment had the lowest. Soybean yield, number of pods per plant, number of grains per plant, and 100-grain weight all decreased and then increased with increasing groundwater depth, following an order of D1>D4>D2>D3. Soybean yield was significantly positively correlated with groundwater recharge, which was positively correlated with plant height, leaf area index, and dry matter accumulation. Our results indicated that the D1 treatment with adequate groundwater recharge increased plant height, leaf area index, and dry matter accumulation, coordinated the distribution and translocation of dry matter among all plant parts in the late soybean growth period, and ultimately achieved the highest yield. When groundwater depth was deep (D4), groundwater recharge was small. In such case, the growth and development status and yield of soybean could also reach a high level if there was sufficient water supply.

Cellular Protein Aggregates: Formation, Biological Effects, and Ways of Elimination.

The accumulation of protein aggregates is the hallmark of many neurodegenerative diseases. The dysregulation of protein homeostasis (or proteostasis) caused by acute proteotoxic stresses or chronic expression of mutant proteins can lead to protein aggregation. Protein aggregates can interfere with a variety of cellular biological processes and consume factors essential for maintaining proteostasis, leading to a further imbalance of proteostasis and further accumulation of protein aggregates, creating a vicious cycle that ultimately leads to aging and the progression of age-related neurodegenerative diseases. Over the long course of evolution, eukaryotic cells have evolved a variety of mechanisms to rescue or eliminate aggregated proteins. Here, we will briefly review the composition and causes of protein aggregation in mammalian cells, systematically summarize the role of protein aggregates in the organisms, and further highlight some of the clearance mechanisms of protein aggregates. Finally, we will discuss potential therapeutic strategies that target protein aggregates in the treatment of aging and age-related neurodegenerative diseases.

Effect of Lacking ZKSCAN3 on Autophagy, Lysosomal Biogenesis and Senescence.

Transcription factors can affect autophagy activity by promoting or inhibiting the expression of autophagic and lysosomal genes. As a member of the zinc finger family DNA-binding proteins, ZKSCAN3 has been reported to function as a transcriptional repressor of autophagy, silencing of which can induce autophagy and promote lysosomal biogenesis in cancer cells. However, studies in Zkscan3 knockout mice showed that the deficiency of ZKSCAN3 did not induce autophagy or increase lysosomal biogenesis. In order to further explore the role of ZKSCAN3 in the transcriptional regulation of autophagic genes in human cancer and non-cancer cells, we generated ZKSCAN3 knockout HK-2 (non-cancer) and Hela (cancer) cells via the CRISPR/Cas9 system and analyzed the differences in gene expression between ZKSCAN3 deleted cells and non-deleted cells through fluorescence quantitative PCR, western blot and transcriptome sequencing, with special attention to the differences in expression of autophagic and lysosomal genes. We found that ZKSCAN3 may be a cancer-related gene involved in cancer progression, but not an essential transcriptional repressor of autophagic or lysosomal genes, as the lacking of ZKSCAN3 cannot significantly promote the expression of autophagic and lysosomal genes.

Genome-centric polyhydroxyalkanoate reconciliation reveals nutrient enriched growth dependent biosynthesis in Bacillus cereus IBA1.

Microbiological polyhydroxyalkanoates (PHAs) are rooted as the most promising bio-replacements of synthetic polymers. Inherent properties of these PHAs further expand their applicability in numerous industrial, environmental, and clinical sectors. To propel these, a new environmental, endotoxin free gram-positive bacterium i.e., Bacillus cereus IBA1 was identified to harbor advantageous PHA producer characteristics through high-throughput omics mining approaches. Unlike traditional fermentations, nutrient enriched strategy was used to enhance PHA granular concentrations by ∼2.3 folds to 2.78 ± 0.19 g/L. Additionally, this study is the first to confirm an underlying growth dependent PHA biogenesis through exploring PHA granule associated operons which harbour constitutively expressing PHA synthase (phaC) coupled with differentially expressing PHA synthase subunit (phaR) and regulatory protein (phaP, phaQ) amid different growth phases. Moreover, the feasibility of this promising microbial phenomenon could propel next-generation biopolymers, and increase industrial applicability of PHAs, thereby significantly contributing to the sustainable development.

A review on mechanistic understanding of microplastic pollution on the performance of anaerobic digestion.

Anaerobic digestion (AD) has emerged as a promising technology for diverting the organic waste from the landfills along with the production of clean energy. AD is a microbial-driven biochemical process wherein the plethora of microbial communities participate in converting the putrescible organic matter into biogas. Nevertheless, the AD process is susceptible to the external environmental factors such as presence of physical (microplastics) and chemical (antibiotics, pesticides) pollutants. The microplastics (MPs) pollution has received recent attention due to the increasing plastic pollution in terrestrial ecosystems. This review was aimed for holistic assessment of impact of MPs pollution on AD process to develop efficient treatment technology. First, the possible pathways of MPs entry into the AD systems were critically evaluated. Further, the recent literature on the experimental studies pertaining to the impact of different types of MPs at different concentrations on the AD process was reviewed. In addition, several mechanisms such as direct exposure of MPs on the microbial cells, indirect impact of MPs through the leaching of toxic chemicals and reactive oxygen species (ROS) formation on AD process were elucidated. Besides, the risk possessed by the increase of antibiotic resistance genes (ARGs) after the AD process due to the MPs stress on microbial communities were discussed. Overall, this review deciphered the severity of MPs pollution on AD process at different levels.

Improving performance of pilot-scale ecological bed coupled with microbial electrochemical system for urban tail water treatment.

Recycling urban tail water for ecological base flow and landscape use offers a reliable solution for the problem of water resource shortage. But the long-term direct discharge of urban tail water can aggravate the eutrophication of surface water based on the present drainage standard of sewage plant. It is of great significance to develop low-cost and low-energy ecological technologies as transitional region between urban tail water and surface water. In this study, a pilot-scale ecological bed coupled with microbial electrochemical system (EB-MES) was established to treat urban tail water deeply. The system was operated for 96 days from June to September. Average TN removal efficiency in EB-MES under the condition of submerged plant coupled closed-circuit MES could reach 59.0 ± 16.6 %, which was 82.7 % and 38.1 % higher than that of open-circuit EB-MES and MES without plants, respectively. Microbial community structure testing indicated that multiple nitrogen metabolic mechanisms occurred in the system, including nitrification, electrode autotrophic denitrification, anammox, simultaneous nitrification and denitrification, and aerobic denitrification, which results in better denitrification efficiency under tail water. Our research provided a novel ecological technology with advantages of high-efficiency, low-energy and low-carbon and verified the feasibility in pilot scale for application in the advanced treatment of urban tail water.

Effect of different-sized bulking agents on nitrification process during food waste digestate composting.

Food waste digestate (FWD) disposal is a serious bottleneck in anaerobic digestion plants to achieve a circular bioeconomy. FWD could be recycled into nitrogen-rich compost; however, the co-composting process optimisation along with bulking agents is required to reduce nitrogen loss and unwanted gaseous emissions. In the present study, two different-sized bulking agents, namely, wood shaving (WS) and fine sawdust (FS), were used to investigate their impact on FWD composting performance along with the nitrogen dynamics. The mixing of FWD with different bulking agents altered the physiochemical characteristics of composting matrix and the effective composting performance was observed through reduced ammonium nitrogen and increased seed germination index during 28 days of composting. The carbon loss of 19-22% through CO2 emission indicated similar carbon mineralisation with both types of sawdust; however, the nitrogen transformation pathways were different. Only WS treatment demonstrated the nitrification process, whereas the nitrogen loss was higher with FS. A total nitrogen loss of ∼15% was observed in treatments with FS, whereas WS treatments displayed a nitrogen loss of 12%. The outcome of the present study could significantly contribute to the practical aspect of the FWD composting operation with the promotion of the bio-recycling economy.

Role of tobacco and bamboo biochar on food waste digestate co-composting: Nitrogen conservation, greenhouse gas emissions, and compost quality.

Anaerobic digestion is considered an environmentally benign process for the recycling of food waste into biogas. However, unscientific disposal of ammonium-rich food waste digestate (FWD), a by-product of anaerobic digestion induces environmental issues such as odor nuisances, water pollution, phytotoxicity and pathogen transformations in soil, etc. In the present study, FWD produced from anaerobic digestion of source-separated food waste from markets and industries was used for converting FWD into biofertilizer using 20-L bench scale composters. The issues of nitrogen loss, NH3 volatilization, and greenhouse gas N2O emission were addressed using in-situ composting technologies with the aid of tobacco and bamboo biochar produced at pyrolytic temperatures of 450 °C and 600 °C, respectively. The results demonstrated that the phytotoxic nature of FWD could be reduced into a nutrient-rich compost by mitigating nitrogen loss by 29-53% using 10% tobacco and 10% bamboo biochar in comparison with the control treatment. Tobacco biochar mitigates NH3 emission by 63% but enhances the N2O emission by 65%, whereas bamboo biochar mitigates both NH3 and N2O emissions by 48% and 31%, respectively. Overall, 10% tobacco and 10% bamboo biochar amendment could reduce total nitrogen loss by 29% and 53%, respectively. Furthermore, the biochar addition significantly enhanced the biodegradation rate of FWD and the mature compost could be produced within 21 days of FWD composting as seen by an increased seed germination index (>50% on dry weight basis). The results of this study could be beneficial in developing a circular bioeconomy locally with the waste-derived substrates.

Effect of Chinese medicinal herbal residues compost on tomato and Chinese cabbage plants: Assessment on phytopathogenic effect and nutrients uptake.

Chinese medicinal herbal residues (CMHRs) are known for their antipathogenic properties due to the presence of bioactive compounds. Hence, CMHRs could be used as a potential resource to produce biofertilizer with antipathogenic properties for agricultural applications. In this study, a novel approach was used by utilizing the waste-derived biofertilizer, i.e., CMHRs compost (CMHRC) as a nutrient supplier as well as an organic bioagent against Alternaria solani (A. solani) and Fusarium oxysporum (F. oxysporum) on tomato (Lycopersicon esculentum) and Chinese cabbage (Brassica rapa subsp. Chinensis) plants. The experiments were conducted under greenhouse conditions using locally collected acidic soil wherein 2%, 5% and 10% CMHRC (dry weight) along with 5% food waste compost were used as treatments. In addition, only soil and soil with phytopathogens were used as control treatments. The results suggested that amending the compost into acidic soil significantly increased the pH to a neutral level along with enhanced uptake of nutrients. Among all the treatments, 5% CMHRs compost addition increased the tomato plant biomass production to 4.9 g/pot (dry weight) compared to 2.2 g/pot in control. A similar trend was observed in Chinese cabbage plants and the improved plant biomass production could be attributed to the combined effect of strong nutrient absorption ability by healthy roots and enhanced nutrient supply. At 5% CMHRC application rate, the nitrogen uptake by tomato and Chinese cabbage plants increased by 78% and 62%, respectively, whereas phosphorous uptake increased by 75% and 25%, respectively. The reduction in A. solani by 48% and F. oxysporum by 54% in the post-harvested soil of 5% CMHRC treatment against the control demonstrated the anti-phytopathogenic efficiency of CMHRC compost. Hence, the present study illustrates the beneficiary aspects of utilizing CMHRs to produce biofertilizer with anti-phytopathogenic properties which can be safely used for tomato and Chinese cabbage plant growth.

Macrophage autophagy in macrophage polarization, chronic inflammation and organ fibrosis.

As the essential regulators of organ fibrosis, macrophages undergo marked phenotypic and functional changes after organ injury. These changes in macrophage phenotype and function can result in maladaptive repair, causing chronic inflammation and the development of pathological fibrosis. Autophagy, a highly conserved lysosomal degradation pathway, is one of the major players to maintain the homeostasis of macrophages through clearing protein aggregates, damaged organelles, and invading pathogens. Emerging evidence has shown that macrophage autophagy plays an essential role in macrophage polarization, chronic inflammation, and organ fibrosis. Because of the high heterogeneity of macrophages in different organs, different macrophage types may play different roles in organ fibrosis. Here, we review the current understanding of the function of macrophage autophagy in macrophage polarization, chronic inflammation, and organ fibrosis in different organs, highlight the potential role of macrophage autophagy in the treatment of fibrosis. Finally, the important unresolved issues in this field are briefly discussed. A better understanding of the mechanisms that macrophage autophagy in macrophage polarization, chronic inflammation, and organ fibrosis may contribute to developing novel therapies for chronic inflammatory diseases and organ fibrosis.

Hydrochar prepared from digestate improves anaerobic co-digestion of food waste and sewage sludge: Performance, mechanisms, and implication.

This work reported a new waste functionalization and utilization method, which use digestate to prepare hydrochar to improve methane production from food waste (FW) and sewage sludge (SS). Experimental results presented that 10 g/L hydrochar obtained the cumulative methane production of 133.11 ± 1.18 mL/g volatile solids added, 26.99 % higher than that without hydrochar addition. By monitoring the conversion of model metabolic intermediates, 10 g/L hydrochar was determined to favor hydrolysis, acidogenesis and methonogenesis bio-processes involved in methane production, thus improving the degradation of solubilized organics and consumption of short-chain fatty acids (SCFAs) during the co-digestion. Microbial investigation revealed that 10 g/L hydrochar enriched the microbes relevant to methane production (e.g., Methanosaeta and Syntrophomonas), but reduced the abundances of hydrolysis- and acidogenesis-related microbes (e.g., Acinetobacter). This hydrochar-based preparation and utilization strategy might offer a novel paradigm for waste-control-waste, bringing economic and environmental benefits.

Autophagy and Renal Fibrosis.

Renal fibrosis is a common process of almost all the chronic kidney diseases progressing to end-stage kidney disease. As a highly conserved lysosomal protein degradation pathway, autophagy is responsible for degrading protein aggregates, damaged organelles, or invading pathogens to maintain intracellular homeostasis. Growing evidence reveals that autophagy is involved in the progression of renal fibrosis, both in the tubulointerstitial compartment and in the glomeruli. Nevertheless, the specific role of autophagy in renal fibrosis has still not been fully understood. Therefore, in this review we will describe the characteristics of autophagy and summarize the recent advances in understanding the functions of autophagy in renal fibrosis. Moreover, the problem existing in this field and the possibility of autophagy as the potential therapeutic target for renal fibrosis have also been discussed.