Publications by authors named "Huu-Hao Ngo"

Article Synopsis
  • Sulfur autotrophic denitrification (SADN) is a bioremediation method aimed at removing nitrates from contaminated water, but its efficiency is limited by the low availability of sulfur.
  • A proposed solution, the sulfur autotrophic disproportionation (SADP) process, effectively converts sulfur into biogenic sulfide, increasing the availability of electron donors necessary for SADN.
  • Laboratory tests showed that the combination of SADP and SADN significantly improved nitrate removal rates and reduced nitrous oxide emissions, making it a promising and sustainable approach for treating nitrate-contaminated water.
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Understanding the relationship between recharge water quality and algal metabolism is critical for managing eutrophication in urban landscape water bodies. This study investigates six landscape water bodies in Xi'an City, utilizing natural and reclaimed water recharge sources to cultivate and evaluate the growth and biomass composition of Chlorella vulgaris. The findings revealed that the growth and metabolic rate of C.

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The incorporation of biochar can significantly enhance the performance of anaerobic membrane bioreactors (AnMBRs), achieving up to a 95 % increase in pollutant removal efficiency and an 86 % improvement in methane production. Algae biochar, in particular, shows great promise as an effective additive in AnMBR systems because of its low cost (approximately $0.470/kg) and the abundance of raw material sources.

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Microplastics are small plastic pieces ranging in size from 1μ to <5 mm in diameter, are water-soluble, and can be either primary as they are initially created in small sizes or secondary as they develop due to plastic degradation. Approximately 360 million tons of plastic are produced globally every year, with only 7% recycled, leaving the majority of waste to accumulate in the environment and pose a serious threat in the form of microplastics. All ecosystems, particularly freshwater ecosystems, experience microplastic accumulation and are also prone to degrading processes.

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Microplastics pose detrimental effects on the environment, aquatic products, and human health. This comprehensive analysis highlights the repercussions of microplastic contamination within aquaculture. Microplastics in aquaculture are primarily from land-based plastic waste, tourism-related disposal, shipping activities, fisheries/aquaculture, and atmospheric deposition.

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Dissolved organic matter (DOM) present in aquatic environments can significantly influence microalgal metabolism and the enrichment of heavy metals. However, the specific mechanism through which typical DOM affects the enrichment of the heavy metal chromium (Cr) in green algae remains unclear. This study investigates the impacts of varying concentrations of humic acid (HA), selected as a representative DOM in water, on the growth, metabolism, and Cr enrichment in Chlorella vulgaris, a typical green alga.

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Rice cultivation boasts a rich historical legacy, serving as the primary sustenance for over 50% of the global population. However, the cultivation process gives rise to the emission of methane (CH) and nitrous oxide (NO), two potent greenhouse gases. Notably, the global warming potential (GWP) of CH and NO surpasses CO by 27-30 times and 273 times over 100 years, respectively.

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Membrane aerated biofilm reactor (MABR) is challenged by biofilm thickness control and phosphorus removal. Air scouring aided by computational fluid dynamics (CFD) was employed to detach outer biofilm in sequencing batch MABR treating low C/N wastewater. Biofilm with 177-285 µm thickness in cycle 5-15 achieved over 85 % chemical oxygen demand (COD) and total inorganic nitrogen (TIN) removals at loading rate of 13.

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Producing medium chain fatty acids (MCFAs) from waste activated sludge (WAS) is crucial for sustainable chemical industries. This study addressed the electron donor requirement for MCFAs production by inoculating Lactobacillus at varying concentrations (7.94 × 10, 3.

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Numerous antibiotics are being released into the natural environment through wastewater. As antibiotic usage increases annually, its detrimental impact on the environment is escalating. Addressing environmental sustainability and human health requires significant attention towards antibiotic removal.

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A biochar-assisted anaerobic membrane bioreactor (BC-AnMBR) was conducted to evaluate the performance in treating swine wastewater with different organic loading rates (OLR) ranging from 0.38 to 1.13 kg-COD/(md).

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Many waterborne diseases are related with viruses, and COVID-19 worldwide has raised the concern of virus security in water into the public horizon. Compared to other conventional water treatment processes, membrane technology can achieve satisfactory virus removal with fewer chemicals, and prevent the outbreaks of viruses to a maximal extent. Researchers developed new modification methods to improve membrane performance.

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For the first time, a hyper-thermophilic aerobic (>60 °C) bioreactor has been integrated with direct submerged membrane distillation (MD), highlighting its potential as an advanced wastewater treatment solution. The hyper-thermophilic aerobic bioreactor, operating up to 65 °C, is tailored for high organic removal, while MD efficiently produces clean water. Throughout the study, high removal rates of 99.

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Membrane bioreactors (MBRs) hold significant promise for wastewater treatment, yet the persistent challenge of membrane fouling impedes their practical application. One promising solution lies in the synergy between microalgae and bacteria, offering efficient nutrient removal, reduced energy consumption, and potential mitigation of extracellular polymeric substances (EPS) concentrations. Inoculating microalgae presents a promising avenue to address membrane fouling in MBRs.

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The performance of partial nitritation (PN)-moving bed biofilm reactor (MBBR) in removal of antibiotics in the sidestream wastewater has not been investigated so far. In this work, the removal of ciprofloxacin was assessed under varying free nitrous acid (FNA) levels and different trophic modes. For the first time, a positive correlation was observed between ciprofloxacin removal and FNA levels, either in the autotrophic PN-MBBR or in the mixotrophic PN-MBBR, mainly ascribed to the FNA-stimulating effect on heterotrophic bacteria (HB)-induced biodegradation.

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Microbial fuel cells (MFCs), known for their low energy consumption, high efficiency, and environmental friendliness, have been widely utilized for removing antibiotics from wastewater. Compared to conventional wastewater treatment methods, MFCs produce less sludge while exhibiting superior antibiotic removal capacity, effectively reducing the spread of antibiotic resistance genes (ARGs). This study investigates 1) the mechanisms of ARGs generation and proliferation in MFCs; 2) the influencing factors on the fate and removal of antibiotics and ARGs; and 3) the fate and mitigation of ARGs in MFC and MFC-coupled systems.

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In recent years, biofuel production has attracted considerable attention, especially given the increasing worldwide demand for energy and emissions of greenhouse gases that threaten this planet. In this case, one possible solution is to convert biomass into green and sustainable biofuel, which can enhance the bioeconomy and contribute to sustainable economic development goals. Due to being in large quantities and containing high organic content, various biomass sources such as food waste, textile waste, microalgal waste, agricultural waste and sewage sludge have gained significant attention for biofuel production.

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This review article explores the challenges associated with landfill leachate resulting from the increasing disposal of municipal solid waste in landfills and open areas. The composition of landfill leachate includes antibiotics (0.001-100 μg), heavy metals (0.

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Slow dissolution/hydrolysis of insoluble/macromolecular organics and poor sludge filterability restrict the application potential of anaerobic membrane bioreactor (AnMBR). Bubble-free membrane microaeration was firstly proposed to overcome these obstacles in this study. The batch anaerobic digestion tests feeding insoluble starch and soluble peptone with and without microaeration showed that microaeration led to a 65.

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At present, the application of sewage treatment technologies is restricted by high sulfate concentrations. In the present work, the sulfate removal was biologically treated using an upflow anaerobic sludge blanket (UASB) in the absence/presence of light. First, the start-up of UASB for the sulfate removal was studied in terms of COD degradation, sulfate removal, and effluent pH.

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Biochar has emerged as a versatile and efficient multi-functional material, serving as both an adsorbent and catalyst in removing emerging pollutants (EPs) from aquatic matrices. However, pristine biochar's catalytic and adsorption capabilities are hindered by its poor surface functionality and small pore size. Addressing these limitations involves the development of functionalized biochar, a strategic approach aimed at enhancing its physicochemical properties and improving adsorption and catalytic efficiencies.

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In lightly polluted water containing heavy metals, organic matter, and green microalgae, the molecular weight of organic matter may influence both the growth of green microalgae and the concentration of heavy metals. This study elucidates the effects and mechanisms by which different molecular weight fractions of fulvic acid (FA), a model dissolved organic matter component, facilitate the bioaccumulation of hexavalent chromium (Cr(VI)) in a typical green alga, Chlorella vulgaris. Findings show that the addition of FA fractions with molecular weights greater than 10 kDa significantly enhances the enrichment of total chromium and Cr(VI) in algal cells, reaching 21.

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Ammonium removal by a symbiosis system of algae (Chlorella vulgaris) and nitrifying bacteria was evaluated in a long-term photo-sequencing batch reactor under varying influent inorganic carbon (IC) concentrations (15, 10, 5 and 2.5 mmol L) and different nitrogen loading rate (NLR) conditions (270 and 540 mg-N L d). The IC/N ratios provided were 2.

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Establishing an economic and sustained Fenton oxidation system to enhance sludge dewaterability and carbamazepine (CBZ) removal rate is a crucial path to simultaneously achieve sludge reduction and harmless. Leveraging the principles akin to "tea making", we harnessed tea waste to continually release tea polyphenols (TP), thus effectively maintaining high level of oxidation efficiency through the sustained Fenton reaction. The results illustrated that the incorporation of tea waste yielded more favorable outcomes in terms of water content reduction and CBZ removal compared to direct TP addition within the Fe(III)/hydrogen peroxide (HO) system.

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The co-transport behavior of environmental pollutants with biochar particles has aroused great interests from researchers due to the concerns about pollutant diffusion and environmental exposure after biochar is applied to soil. In this work, the recovery and co-transport behavior of biochar micron-/nano-particles (BCMP and BCNP) and lead (Pb) in saturated porous media were investigated under different ionic strength conditions (IS = 1, 5 and 10 mM) under a direct current electric field. The results showed that the electric field could significantly enhance the mobility of Pb adsorbed biochar particles, particularly BCNP.

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