Electro-Enhanced Separation of Microsized Oil-in-Water Emulsions via Metallic Membranes: Performance and Mechanistic Insights.

Conventional separation membranes suffer from evitable fouling and flux decrease for water treatment applications. Herein, a novel protocol of electro-enhanced membrane separation is proposed for the efficient treatment of microsized emulsions (∼1 µm) by rationally designing robust electroresponsive copper metallic membranes, which could mitigate oil fouling and coenhance permeance (from ∼1026 to ∼2516 L·m-2·h-1·bar-1) and rejection (from ∼87 to ∼98%). High-flux Cu membranes exhibit superior ductility and electrical conductivity, enabling promising electroactivity. Separation performance and the fouling mechanism were studied under different electrical potentials and ionic strengths. Application of negative polarization into a large-pore (∼2.1 µm) Cu membrane is favorable to not only almost completely reject smaller-sized oil droplets (∼1 µm) but also achieve antifouling and anticorrosion functions. Moreover, surfactants around oil droplets might be redistributed due to electrostatic repulsion, which effectively enhances the steric hindrance effect between neighboring oil droplets, mitigating oil coalescence and consequently membrane fouling. Furthermore, due to the screening effect of surfactants, the presence of low-concentration salts increases the adsorption of surfactants at the oil-water interface, thus preventing oil coalescence via decreasing oil-water interfacial tension. However, under high ionic strengths, the fouling mechanism converts from cake filtration to a complete blocking model due to the reduced electrostatic repulsion between the Cu membrane and oil droplets. This work would provide mechanistic insights into electro-enhanced antifouling for not only oil emulsion separation but also more water treatment applications using rationally designed novel electroresponsive membranes.

Enhancing harvest of biodiesel-promising microalgae using Daphnia domesticated by amino acids.

Mass production of microalgal biodiesel is hindered by microalgae harvesting efficiency and costs. In this study, Daphnia domesticated by amino acids were used to harvest microalgae via ingesting. The main factors (density of Daphnia, salinity, pH, light-environment, temperature and algal concentration) that were conducive to Daphnia feeding were optimized. Under the optimal condition, Microalgae-feeding Daphnia were domesticated by adding D-glutamic acid and L-cysteine as stimulating factors. After that, the ingestion rate of domesticated Daphnia increased by 24.93%. The presence of Daphnia as a predator can induce microalgae to mass into clusters. Combining Daphnia feeding and the inductive defense flocculation of microalgae, the harvesting rate of mixed algae (Chlorella pyrenoidosa and Scenedesmus obliquus) reached over 95% after 9 h. Overall, this work suggested that Daphnia feeding process is a green and economical approach for microalgae harvesting.

Engineering a Nanocomposite Interlayer for a Novel Ceramic-Based Forward Osmosis Membrane with Enhanced Performance.

Rational design of a high-performance defect-free polyamide (PA) layer on a robust ceramic substrate is challenging for forward osmosis (FO) water treatment applications. In this study, we first demonstrated a robust ceramic-based thin-film composite (TFC) FO membrane by engineering a novel nanocomposite interlayer of titanium dioxide and carbon nanotube (TiO2/CNT). The structural morphologies and properties were systematically characterized for different substrates (without interlayer, with TiO2 interlayer, or with TiO2/CNT interlayer) and the corresponding ceramic-based TFC-FO membranes. Introduction of low roughness nanocomposite interlayers with decreased pore size created an interface with improved surface characteristics, favoring the formation of a defect-free nanovoid-containing PA layer with high cross-linking degree. The resulting ceramic-based FO membrane had a water permeability of approximately 2 L/(m2 h bar) and a NaCl rejection of 98%, showing simultaneous enhancements in both compared to the control membrane without an interlayer. Mechanism analysis indicates that such a special nanocomposite interlayer not only provided more active sites for the formation of a thinner defect-free nanovoid-containing PA layer without penetration into substrate but also acted as a highly porous three-dimensional network structure for rapid water transport. This work provides a novel protocol for rational design and fabrication of a high-performance multilayered inorganic FO membrane as well as extended applications in water treatment with enhanced performance.

Sequential 'acid leaching-anion exchange-aerobic composting' process for recycle of municipal sludge.

Municipal sludge disposal and recycle has become a prominent research theme. In this study, a sequential process for integral treatment of municipal sludge was primarily presented, combining acid leaching, anion exchange and aerobic composting. The aim of the process was to remove chromium (Cr) from the sludge and reuse the sludge as manure. Firstly, Cr was removed from municipal sludge via the acid leaching process; the removal rate was up to 57.43%. Then, ion exchange resin was used to remove Cr from leachate; the removal rate reached 95%. Aluminum sheet was used to replace the Cr from eluent; the replacement rate was 63.3%. The aerobic composting process could be successfully warmed up to above 55 °C and lasted for 4 days; the seed germination index reached 68.3%. After the composting process, the residual Cr in sludge mainly existed at a more stable residual state and organic binding state. Overall, this novel sequential process serves as a potential high-efficiency, green, low-energy way for municipal sludge recycle.

Microalgae harvesting by magnetic flocculation for biodiesel production: current status and potential.

With the increasing demand for energy, microalgae, as one of the promising feedstocks of biodiesel, has raised great awareness. Because of its small size, similar density to water and electrical stability, harvesting methods of microalgae that have low energy consumption and that are highly efficient, easy to large-scale and environmentally friendly have become a bottleneck restricting development of the whole process. Among the numerous possible harvesting methods, magnetic flocculation has the advantages of simple operation, fast separation and energy saving and thus is considered as a promising novel harvesting method. In this review, we have summarized the updated status and application potential of magnetic flocculation, including the principle of magnetic flocculation, magnetic flocculating materials, flocculating efficiency and its effect on downstream process. The major challenges such as magnetic materials recovery, large-scale magnetic flocculation device design, and magnetic flocculation costs are also discussed.

Geraniol and lupeol inhibit growth and promote apoptosis in human hepatocarcinoma cells through the MAPK signaling pathway.

OBJECTIVES: Hepatocarcinoma is one of the most lethal cancers, leading to a 5-year survival rate as low as 30% due to recurrence and metastasis. The treatment of liver cancer includes surgery and medication, of which, the former is more effective. However, surgical resection is applicable in less than 40% of patients. Therefore, it is imperative to find effective medication options for liver cancer therapy. METHODS: In this study, we found that two natural products, geraniol and lupeol, had antiproliferative and proapoptotic effects on the hepatocarcinoma cell lines SMMC7721 and HepG2. We also detected a lower expression level of Bcl-2 and upregulation of BAX and caspase in the presence of geraniol and lupeol. RESULTS: Furthermore, geraniol or lupeol also altered the phosphorylation level of extracellular signal-regulated protein kinase, P38, and c-Jun NH2-terminal kinases, suggesting involvement in mitogen-activated protein kinase signaling. CONCLUSIONS: This study provided direct evidence to support the effect of geraniol and lupeol in hepatocarcinoma cell growth and apoptosis, which indicated the potential application of these two natural products in anti-liver cancer therapy.

Operation performance of an A/O process combined sewage sludge treatment and phosphorus recovery using human urine.

A novel sewage sludge treatment process is developed in which sludge anaerobically phosphorus (P) released with the temperature control/ultrasonic treatment and recovery with human urine are incorporated to a conventional anaerobic/aerobic (A/O) process. The results showed that temperature affected the anaerobic P release and the maximum orthophosphate (PO4 3-P) release rate was 21.68 mg PO4 3-P/(g MLVSS.h) at 20 °C. The optimal specific energy of ultrasonic treatment was 15,000 kJ/kg TS, at which the solubilization degree of soluble chemical oxygen demand (SCOD) was 37.93%, which verified that the anaerobic sludge flocs were broken and the organic matter was obviously released. Human urine and P-rich sludge stream could be verified as a feasible way of P recovery in the form of struvite. The output of P in the combined A/O treatment process consisted of three pathways (i.e., effluent wastewater, sewage sludge, and P recovery). The influent P could be recovered by 22.84% and about 1.48 g/d potential struvite could be recovered from the anaerobic sludge flow using 0.27 L/d-human urine. The mass balances of COD and nitrogen (N) indicated that the combined A/O process also improved the organic mineralization and the removal of N.

Subcritical n-hexane/isopropanol extraction of lipid from wet microalgal pastes of Scenedesmus obliquus.

Subcritical co-solvents of n-hexane/isopropanol were primarily utilized to extract lipid from wet microalgal pastes of Scenedesmus obliquus. The effects of key operational parameters were investigated, and the optimal parameters were obtained: solvent ratio of n-hexane to isopropanol was 3:2 (V:V), phase ratio of co-solvents to microalgal biomass was 35:1 (mL:g), reactor stirring speed was 900 rpm, extraction time was 60 min. Additional pretreatment with acid, ultrasonic and microwave as well as enhanced subcritical pressure/heating treatments were also applied to further study their effects on lipid extraction. The results showed that the lipid recovery rate with acid pretreatment was 8.6 and 6.2% higher than ultrasonic and microwave pretreatment; the optimum enhanced subcritical condition was 55 °C with atmospheric pressure. Under optimal operating conditions, the lipid and FAME yield were 13.5 and 7.2%, which was 82.6 and 135.1% higher than the traditional method. The results indicated that the subcritical n-hexane/isopropanol extraction process had promising application potential.

Enhancing dewaterability of waste activated sludge by combined oxidative conditioning process with zero-valent iron and peroxymonosulfate.

The enhancement of sludge dewaterability is of great importance for facilitating the sludge disposal during the operation of wastewater treatment plants. In this study, a novel oxidative conditioning approach was applied to enhance the dewaterability of waste activated sludge by the combination of zero-valent iron (ZVI) and peroxymonosulfate (PMS). It was found that the dewaterability of sludge was significantly improved after the addition of ZVI (0-4 g/g TSS) (TSS: total suspended solids) and PMS (0-1 g/g TSS). The optimal addition amount of ZVI and PMS was 0.25 g/g TSS and 0.1 g/g TSS, respectively, under which the capillary suction time of the sludge was reduced by approximately 50%. The decomposition of sludge flocs could contribute to the improved sludge dewaterability. Economic analysis demonstrated that the proposed conditioning process with ZVI and PMS was more economical than the ZVI + peroxydisulfate and the traditional Fenton conditioning processes.

Optimization of aeration for biodiesel production by Scenedesmus obliquus grown in municipal wastewater.

Despite the significant breakthroughs in research on microalgae as a feedstock for biodiesel, its production cost is still much higher than that of fossil diesel. One possible solution to overcome this problem is to optimize algal growth and lipid production in wastewater. The present study examines the optimization of pretreatment of municipal wastewater and aeration conditions in order to enhance the lipid productivity of Scenedesmus obliquus. Results showed that no significant differences were recorded in lipid productivity of S. obliquus grown in primary settled or sterilized municipal wastewater; however, ultrasound pretreatment of wastewater significantly decreased the lipid production. Whereas, aeration rates of 0.2 vvm significantly increased lipid content by 51 %, with respect to the non-aerated culture, which resulted in maximum lipid productivity (32.5 mg L(-1) day(-1)). Furthermore, aeration enrichment by 2 % CO2 resulted in increase of lipid productivity by 46 % over the CO2 non-enriched aerated culture. Fatty acid profile showed that optimized aeration significantly enhanced monounsaturated fatty acid production, composed mainly of C18:1, by 1.8 times over the non-aerated S. obliquus culture with insignificant changes in polyunsaturated fatty acid proportion; suggesting better biodiesel characteristics for the optimized culture.

Biofuel production from microalgae as feedstock: current status and potential.

Algal biofuel has become an attractive alternative of petroleum-based fuels in the past decade. Microalgae have been proposed as a feedstock to produce biodiesel, since they are capable of mitigating CO2 emission and accumulating lipids with high productivity. This article is an overview of the updated status of biofuels, especially biodiesel production from microalgae including fundamental research, culture selection and engineering process development; it summarizes research on mathematical and life cycle modeling on algae growth and biomass production; and it updates global efforts of research and development and commercialization attempts. The major challenges are also discussed.

Integrated municipal wastewater treatment and lipid accumulation by a self-flocculating/floating microalga Limnothrix sp.

The present study evaluated the growth, self-flocculation, lipid content, and pollutants removal by Limnothrix sp. BASMWW-9 isolated from municipal wastewater treatment system and cultivated in municipal wastewater. The biomass yield and lipid content after 6 days of cultivation were 1.07 g dw/L and 27.34 %dw, respectively. In addition, its self-flocculating ability reached up to 90 % after harvesting time of 180 min. Moreover, COD,NH3-N, TN, and TP removalefficiencies were 71.65 %, 81.89 %, 74.64 %, and 80.16 %, respectively. The self-flocculation performance of Limnothrix sp. was greatly associated to its morphology and production of extracellular polymeric substances (EPS), with significant positive impact of the high calcium and magnesium content in municipal wastewater. Interestingly, blue light irradiation during harvest enhanced the aggregation and floc formation as a floating biomat, which was attributed to enhanced polysaccharides production. This study provides innovative harvest method for Limnothrix sp. BASMWW-9 cultivated in wastewater using blue light for enhanced lipid recovery.

Responses of physiological, microbiome and lipid metabolism to lignocellulose wastes in gut of yellow mealworm (Tenebrio molitor).

There is limited research on physiological and degradation mechanisms of yellow mealworm, a novel organic waste converter, in processing lignocellulosic wastes. This study has selected two types of lignocellulosic wastes, distillers' grains (DG) and maize straw (MS), to feed yellow mealworms. This study investigated the effects of lignocellulosic wastes on the growth, antioxidant system, microbiome, and lipidome of yellow mealworms. The relative growth of lignocellulosic waste group was not significantly different from wheat bran. The antioxidant level was elevated in DG. MS was significantly enriched in cellulose-degrading bacteria in the gut and was accompanied by disturbances in lipid metabolism. The correlation coefficients were used to construct a network connecting diet, microbiota, and lipids. The correlation analysis indicated that two sphingolipids, hexylglyceramide and dihydroglyceramide, were strongly and positively linked with the dominating species. This study provides comprehensive information on physiological and mechanism of mealworms in process of treating lignocellulosic waste.

Microalgae as future food: Rich nutrients, safety, production costs and environmental effects.

The improvement of food security and nutrition has attracted wide attention, and microalgae as the most promising food source are being further explored. This paper comprehensively introduces basic and functional nutrients rich in microalgae by elaborated tables incorporating a wide variety of studies and summarizes factors influencing their accumulation effects. Subsequently, multiple comparisons of nutrients were conducted, indicating that microalgae have a high protein content. Moreover, controllable production costs and environmental friendliness prompt microalgae into the list that contains more promising and reliable future food. However, microalgae and -based foods approved and sold are limited strictly, showing that safety is a key factor affecting dietary consideration. Notably, sensory profiles and ingredient clarity play an important role in improving the acceptance of microalgae-based foods. Finally, based on the bottleneck in the microalgae food industry, suggestions for its future development were discussed.

Performance and mechanisms of zero valent iron enhancing short-chain fatty acids production during thermophilic anaerobic fermentation of waste activated sludge.

This work first explored the feasibility and possible mechanisms of zero valent iron (ZVI) pretreatment on the generation of short-chain fatty acids (SCFAs) during thermophilic anaerobic fermentation of waste activated sludge (WAS). Results showed that ZVI enhanced the quantity of SCFAs. On Day 6, the SCFAs production reached 455.84 ± 47.88 mg COD/g VSS at 5 g/L of ZVI addition, which increased by 63.80 % relative to control. The presence of ZVI can effectively promote butyric-based fermentation. ZVI accelerated the destruction of extracellular polymeric substances (EPS) and interior sludge cells, as well as improved biodegradation of soluble organics. Also, ZVI enhanced key enzyme activities (i.e., BK and CoA-), thus promoting degradation rates of acidogenesis (6.30 ± 0.84 mg/(gVSS·h) in glucose) and acetogenesis (74.63 ± 0.29 mg/(gVSS·h) in butyrate). Compared to Fe(III), the contribution of Fe(II) was higher among the decomposition products of ZVI. Besides, ZVI favored Proteobacteria and Actinobacteria, which enhanced acetate formation and organic compounds disassimilation of the process, respectively. The abundance of Tepidiphilus, Thermobrachium and Tepidimicrobium was increased, indicating promoting the system stability of SCFAs production in thermophilic anaerobic fermentation.

Enhancing docosahexaenoic acid production in Aurantiochytrium species using atmospheric and room temperature plasma mutagenesis and comprehensive multi-omics analysis.

Aurantiochytrium sp. belongs to marine heterotrophic single-cell protist, which is an important decomposer in marine ecosystem. Aurantiochytrium sp. has gained notoriety because of its ability to accumulate high-value docosahexaenoic acid (DHA), but the key factors of DHA synthesis were unclear at present. In this study, Atmospheric and Room Temperature Plasma technology was applied to the mutagenic breeding of Aurantiochytrium sp., and transcriptomics and proteomics were adopted to analyze the DHA-biosynthesis mechanism. According to the growth and DHA accumulation profiles, the mutant strain Aurantiochytrium sp. R2A35 was selected. The DHA content in total lipids was greatly improved from 49.39 % of the wild strain R2 to 63.69 % of the mutant strain. Moreover, the DHA content in the biomass of Aurantiochytrium sp. R2A35 as 39.72 % was the highest DHA productivity reported so far. The differentially expressed genes distinguished from transcriptome and the TMT-identified differential proteins distinguished from proteome confirmed that the expression of acetyl-CoA carboxylase and ketoacyl reductase was up-regulated by 4.78-fold and 6.95-fold, respectively and the fatty acid synthase was concurrently down-regulated by 2.79-fold, so that more precursor was transported to the polyketide synthase pathway, thereby increasing the DHA yield in Aurantiochytrium sp. R2A35. This research would provide reference for the DHA metabolism process and contribute to the understanding of the decomposer - Aurantiochytrium sp. in marine ecosystems.

Abundance and diversity of ammonia-oxidizing archaea in response to various habitats in Pearl River Delta of China, a subtropical maritime zone.

Ammonia-oxidizing archaea (AOA) are widely considered key to ammonia oxidation in various environments. However, little work has been conducted to simultaneously investigate the abundance and diversity of AOA as well as correlations between archaeal amoA genotypes and environmental parameters of different ecosystems at one district. To understand the abundance, diversity, and distribution of AOA in Pearl River Delta of China in response to various habitats, the archaeal amoA genes in soil, marine, river, lake, hot spring and wastewater treatment plant (WWTP) samples were investigated using real-time fluorescent quantitative PCR and clone libraries. Our analyses indicated that the diversity of AOA in various habitats was different and could be clustered into five major clades, i.e., estuary sediment, marine water/sediment, soil, hot spring and Cluster 1. Phylogenetic analyses revealed that the structure of AOA communities in similar ecological habitats exhibited strong relation. The canonical correspondence method indicated that the AOA community structure was strongly correlated to temperature, pH, total organic carbon, total nitrogen and dissolved oxygen variables. Assessing AOA amoA gene copy numbers, ranging from 6.84 x 10(6) to 9.45 x 10(7) copies/g in dry soil/sediment, and 6.06 x 10(6) to 2.41 x 10(7) copies/L in water samples, were higher than ammonia-oxidizing bacteria (AOB) by 1-2 orders of magnitude. However, AOA amoA copy numbers were much lower than AOB in WWTP activated sludge samples. Overall, these studies suggested that AOA may be a major contributor to ammonia oxidation in natural habitats but play a minor role in highly aerated activated sludge. The result also showed the ratio of AOA to AOB amoA gene abundance was positively correlated with temperature and less correlated with other environmental parameters. New data from our study provide increasing evidence for the relative abundance and diversity of ammonia-oxidizing archaea in the global nitrogen cycle.

Biodegradation of macro- and micro-plastics in environment: A review on mechanism, toxicity, and future perspectives.

Plastic waste has gained remarkable research attention due to its accumulation, associated environmental issues, and impact on living organisms. In order to overcome this challenge, there is an urgent need for its removal from the environment. Under this menace, finding appropriate treatment methods like biodegradation instead of typical treatment methods is of supreme importance. However, there is a limited review on bio-decomposition of plastics, existing microbial species, their degradation efficacy, and mechanism. From this point of view, this study focused on a brief overview of biodegradation such as influencing factors on biodegradation, existing species for macro- and micro-plastics, and present research gap. Degradation percentage, limitations of existing species, and future recommendations are proposed. Microbial species such as bacteria, algae, and fungi have the ability to decompose plastics but they are unable to completely mineralize the plastics. Meanwhile, there is limited knowledge about the involved enzymes in plastics degradation, especially in the case of algae. Bio-decomposition of plastics requires more stringent conditions which are usually feasible for field application. This work will be a reference for new researchers to use this effective strategy for plastic pollution removal.

Modified Hepatic Arterial Infusion Chemotherapy Combined with Lenvatinib and Camrelizumab for Advanced HCC: Two Case Reports.

Background: Advanced-stage hepatocellular carcinoma (HCC), especially huge HCC or portal vein tumour thrombus (PVTT), is difficult to treat, and the prognosis is poor. The advantages of hepatic artery infusion chemotherapy (HAIC) combined with targeted therapy and immunotherapy for this complex disease are gradually becoming apparent. However, HAIC still has some inevitable disadvantages, such as arterial perfusion therapy requiring a long time, which results in many patients having difficulty completing the procedure. Modified HAIC (mHAIC)-based oxaliplatin and S-1 is a new treatment option for huge HCC or PVTT that can reduce complications and improve patient compliance. We report two cases of huge HCC or PVTT that were successfully treated with mHAIC combined with lenvatinib and camrelizumab. The clinical presentations, treatment strategies, and outcomes of these cases are presented. Case Presentation: Case 1: A 52-year-old female was found to have a huge HCC with a size of 14×11 cm. She was treated with one cycle of mHAIC combined with transcatheter arterial chemoembolization (TACE), lenvatinib and camrelizumab and 3 cycles of mHAIC in combination with lenvatinib and camrelizumab. The patient's follow-up maintenance therapy with lenvatinib and camrelizumab has been evaluated for efficacy in achieving complete response (CR). Case 2: A 57-year-old man was diagnosed with advanced HCC in combination with PVTT. He achieved partial remission (PR) after four cycles of mHAIC combined with lenvatinib and camrelizumab. This was followed by treatment with lenvatinib and camrelizumab with an efficacy assessment for CR, and progression-free survival (PFS) was 7 months. Conclusion: For advanced HCC with a large mass or PVTT, mHAIC combined with lenvatinib and camrelizumab is a safe and effective treatment with good patient compliance.

Effects of light intensity and salinity on formation and performance of microalgal-bacterial granular sludge.

Photosynthetic microorganisms in microalgal-bacterial granular sludge offer advantages in wastewater treatment processes. This study examined the effects of light intensity and salinity on microalgal-bacterial granular sludge formation and microbial changes. Activated sludge was inoculated into three bioreactors and operated in batch treatment mode for 100 days under different light intensities (0, 60, and 120 µmol m-2 s-1) and staged increases in salinity concentration (0, 1, 2, and 3%). Results showed that microalgal-bacterial granular sludge was successfully formed within 30 days, and high light exposure increased algal particle stability and inorganic nitrogen removal (63, 66, 71%), while chemical oxygen demand removal (>95%) was similar across groups. High-throughput sequencing results showed that the critical algae were Chlorella and diatoms, while the main bacteria included Paracoccus and Xanthomarina with high extracellular polymeric substance production. This study aims to enhance the comprehension of MBGS processes in saline wastewater treatment under varying light intensities.