Showing papers in "Environmental Technology and Innovation in 2023"
TL;DR: Wang et al. as mentioned in this paper revealed the direct and indirect impact of financial innovations and economic globalization on environmental degradation in China, and the contribution of ecological technologies to environmental degradation is also captured in this study.
Abstract: Technology has long been recognized for driving long-term gains in economic prosperity. However, the role of various technologies, i.e., environmental and financial technologies, for environmental degradation is not yet clear. The on-hand study revealed the direct and indirect impact of financial innovations and economic globalization on environmental degradation in China. Moreover, the contribution of ecological technologies to environmental degradation is also captured in this study. The investigation’s findings publicized that financial innovation directly impacts environmental degradation in China; however, it also indirectly affects the environmental degradation through economic globalization, implying that policies regarding economic globalization would also impact environmental quality in China. Moreover, economic globalization indicated direct and indirect impacts on environmental degradation through environmental technologies. Additionally, the study stated that environmental technologies in China harm environmental quality. The study found a significant and inverted U-shaped affiliation between GDP and ecological footprints. The study elaborated the imperious policies to gain sustainable development without harming environmental sustainability. Granger causality test enlightened the bidirectional feedback between financial innovations and environmental degradation.
10 citations
TL;DR: In this paper , a proposal for the digestate biochar activation and subsequent use in wastewater treatment plants and a financial estimate of the new application is presented. But the application of biochar is limited by demanding requirements for the biochar used (pricy feedstocks or activated in demanding ways).
Abstract: It has been repeatedly and independently proved that biochar applications brings a wide range of environmental advantages. For these benefits to have any tangible impact on a global scale, biochar needs to be applied in substantial quantities. However, the commercial applicability of the most of the research to date is limited by demanding requirements for the biochar used (pricy feedstocks or activated in demanding ways). Nevertheless, such production alternatives increase production costs and thus undermine the financial sustainability of many biochar applications. In contrast, the production of biochar from digestate via waste heat (from methane combustion at a biogas plants) brings several synergies that make it possible to obtain biochar at low production costs and at a constant quality throughout the year. Techno-economic considerations above-reviewed literature indicates for the first time that this competitive advantage can be used for mass scale eutrophication prevention. Based on the synthesis of the reviewed literature, the review is accompanied by (1) a proposal for the digestate biochar activation and subsequent use in wastewater treatment plants and (2) a financial estimate, which indicates the profitability of the new application.
8 citations
TL;DR: In this paper , the authors comprehensively reviewed the progress made in direct air capture, its associated technologies, and the advances made in the state-of-the-art, and proposed to use traditional heating, ventilation, and air conditioning (HVAC) system as a preexisting technology, to capture CO2 directly from the atmosphere, such that the energy needed to capture is provided by the HVAC system of choice.
Abstract: As the concentration of carbon dioxide (CO2) in the atmosphere continues to rise, and the reality of global warming challenges hits the world, global research societies are developing innovative technologies to address climate change challenges brought about by high atmospheric concentration of CO2. One of such challenges is the direct removal of CO2 from the atmosphere. Among all the currently available CO2 removal technologies, direct air capture (DAC) is positioned to deliver the needed CO2 removal from the atmosphere because it is independent of CO2 emission origin, and the capture machine can be stationed anywhere. Research efforts in the last two decades, however, have identified the system overall energy requirements as the bottleneck to the realization of DAC’s commercialization. As a result, global research community continues to seek better ways to minimize the required energy per ton of CO2 removed via DAC. In this work, the literature was comprehensively reviewed to assess the progress made in DAC, its associated technologies, and the advances made in the state-of-the-art. Thus, it is proposed to use traditional heating, ventilation, and air conditioning (HVAC) system (mainly the air conditioning system), as a preexisting technology, to capture CO2 directly from the atmosphere, such that the energy needed to capture is provided by the HVAC system of choice.
7 citations
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5 citations
TL;DR: In this article , an advanced oxidation process for the remediation of polycyclic aromatic hydrocarbons (PAHs) contaminated sediments was developed by the activation of calcium peroxide (CaO2; CP) using a green catalyst prepared from water hyacinth biochar (WHBC), and the associated biochar-driven cellular oxidative stress was highlighted.
Abstract: Polycyclic aromatic hydrocarbons (PAHs), highly concerned emerging contaminant, are priority persistent organic pollutants (POPs) adversely affect the ecological health of marine sediments. These pollutants have attracted widespread attention because of their potential toxicological effects on aquatic organisms and subsequent threats to human health. In this study, an advanced oxidation process for the remediation of PAH-contaminated sediments was developed by the activation of calcium peroxide (CaO2; CP) using a green catalyst prepared from water hyacinth biochar (WHBC), and the associated biochar-driven cellular oxidative stress was highlighted. The catalytic capacity of WHBC was determined at pyrolysis temperature between 300 and 900 °C. WHBC prepared 700 °C (WHBC700) and CP removed 74% of PAHs from the sediment matrix. Results of antioxidant activity evaluation after exposure to WHBC at doses between 400–4000 and 1000–4000 mg L−1 in human hepatocarcinoma cell lines (HepG2) for 24 h showed enhanced glutathione peroxidase (GPx) and catalase (CAT) activities, respectively. Increase in mRNA levels of superoxide dismutase (SOD) genes was also observed after WHBC exposure (400–4000 mg L−1), implying that the oxidative damage caused by reactive oxygen species (ROS) was inhibited by elevating the cellular antioxidant activity. This study attempted to demonstrate an effective waste-to-resource strategy for remediating PAH-polluted sediment in addition to understanding the potential environmental effects of antioxidant activity and gene expression of carbon-based catalysts on HepG2.
5 citations
TL;DR: A literature review of experimental results shows that environmental factors such as pH, metal ion concentration, and adsorbent concentration influenced removal of heavy metals from solutions and this could be a challenge in achieving efficient removal as mentioned in this paper .
Abstract: Providing access to safe and clean drinking water requires that materials and technologies for treating polluted water are affordable, operated without much difficulty and produced locally. To this effect, agricultural wastes, natural soils and materials as well as treatment technologies that are easily put together were investigated. Experimental results indicate that the use of these locally available materials and technologies are viable in removing heavy metals such as lead, zinc, arsenic, copper, cadmium and chromium. The use of banana peels, cassava peels, coconut shells and husks and rice husks were found to have high removal efficiencies in relation to the heavy metals being removed. Natural soils such clay and zeolites were found to be potent in removing heavy metals such as chromium, arsenic and cadmium with significant removal efficiencies. Treatment technologies such as modified ceramic water filters with cerium oxide and iron oxide observed significant heavy metal removal. This literature review of experimental results shows that environmental factors such as pH, metal ion concentration, and adsorbent concentration influenced removal of heavy metals from solutions and this could be a challenge in achieving efficient removal of heavy metals. It is therefore important to improve upon technologies and materials for the efficient removal of heavy metals.
5 citations
TL;DR: In this paper , an externally reflected photoreactor was compared with a solar photoreactors for photocatalytic CO2 conversion in liquid phase using proton-rich functionalized carbon nitride (f-C3N4) modified ZnV 2O6 nanosheets.
Abstract: In this study, a novel externally reflected photoreactor was compared with a solar photoreactor for photocatalytic CO2 conversion in liquid phase using proton-rich functionalized carbon nitride (f-C3N4) modified ZnV 2O6 nanosheets. Effects of operating parameters such as reaction medium and catalyst loading were investigated to maximize yield rates. The performance of photoreactor for CO2 photoconversion was higher in the presence of NaOH solution as a reducing agent than H2O and KHCO3 solution. ZnV2O6 modified with f-C3N4 (1:1) ratio registered the highest CH3OH yield. In an externally reflected photoreactor, the maximum yield rate of CH3OH over ZnV2O6/f-C3N4 (1:1) nanosheets was 4665.6 μmole g-cat −1; 1.25 folds higher than solar photoreactor (3742.1 μmole g-cat−1). The externally reflected photoreactor was found very efficient for photocatalytic CO2 conversion due to its higher light harvesting efficiency compared to the solar photoreactor. The increased yield rates in externally reflected photoreactor were because the reflector provides greater photon flux for dynamic CO2 reduction. Possible reaction mechanisms for photoconversion of CO2 over ZnV2O6/f-C3N4 S-scheme photocatalyst were proposed in order to understand the function of the reflector and the movement of electrons and holes.
4 citations
4 citations
TL;DR: In this paper , using commercial activated carbon as a raw material, magnetic ferric oxide/activated carbon (Fe3O4@AC) was prepared by the chemical co-precipitation method, and Cr(VI) adsorption in water was applied.
Abstract: The removal of a toxic contaminant like Cr(VI) from the water via green adsorbents like biochar and activated carbon is an eco-friendly technique. In this paper, using commercial activated carbon as a raw material, magnetic ferric oxide/activated carbon (Fe3O4@AC) was prepared by the chemical co-precipitation method, and Cr(VI) adsorption in water was applied. The synthesized materials were characterized by advanced characterization techniques including XRD, BET, FT-IR, and XPS. The effects of initial Cr(VI) concentration, temperature, and adsorption time on the adsorption effect of Cr(VI) were evaluated. Results illustrated that the maximum Cr(VI) adsorption achieved by Fe3O4@AC was 45.3 mg/g, with a removal rate of 88.8% at the optimum pH of 2.0 and an adsorption time of 12 h. Under these conditions, Cr(VI) adsorption by Fe3O4@AC fits the pseudo-second-order kinetic model (PSO) and Langmuir isotherm model and is a spontaneous, endothermic, and irreversible process. The results of BET, XRD, FT-IR, and XPS characterization analysis of Cr(VI) before and after adsorption suggested that the adsorption mechanism of Fe3O4@AC is mainly based on chemisorption, supplemented by physical adsorption, accompanied by electrostatic attraction and complexation.
4 citations
TL;DR: In this article , the potential of applying the loess and nanoscale zerovalent iron-amended loess (nZVI-AL) to Pb immobilization was explored.
Abstract: Lead (Pb) can accumulate in organisms causing damage to liver and kidney functions. Preventing Pb2+ migration to surrounding environments is considered of great necessity. This study explored the potential of applying the loess and nanoscale zerovalent iron-amended loess (nZVI-AL) to Pb immobilization. The static equilibrium adsorption analyses showed that the adsorption of Pb2+ by the loess and nZVI-AL was classed as homogeneous monolayer surface adsorption. The nZVI particles provided Pb2+ with more sites for their attachment and prevented their migration using Fe-O and Fe-O-H bonds. Their attachment encouraged the formation of cerussite precipitation, which not only caused the reduction in the diffraction peak of calcite mineral but shifted the peak of adsorption band from around 1430 cm−1 to a lower wavenumber. The unbonded electrons of the functional groups on the surface of quartz mineral coordinated with the empty orbit of Pb2+, leaving the diffraction peak at 3.3429 Å. Further, Ca2＋ distribution of the nZVI-AL sample was not as blurry as that of the loess sample because of the retardant of the depletion of calcite and quartz by the nZVI particles. Moreover, the hydroxyl groups bound via hydrogen bonds were formed by the nZVI amendment, displacing the peak of the adsorption band from 701 cm−1 to 698 cm−1. The hydroxyl groups of clay minerals coordinated with Pb2+ as well to form Pb(OH)+, corresponding to O-H stretching vibrations at 3616 cm−1 and 3430 cm−1 respectively. The nZVI-AL shows its potential in landfills as a bottom liner system.
TL;DR: In this paper , the authors examined the impact of information communication technology, human capital, and globalization on environmental degradation in OECD economies from 1990 to 2018, and found that ICT, renewable energy consumption, and human capital help to bring environmental sustainability in OECD countries.
Abstract: Environmental degradation is one of the major global problems. This is because, like many other regions in the world, OECD countries also contribute to global warming by using non-renewable energy sources to speed up economic growth. Although ICT promotes globalization, no prior research has examined how this trend may affect CO2 emissions in OECD countries. Given this scenario, the current study aims to examine the impact of Information communication technology, human capital, and globalization on environmental degradation in OECD economies from 1990 to 2018. The present study employs second-generation panel econometric techniques, i.e., panel unit root tests (CADF and CIPS), Westerlund co-integration technique, cross-sectional ARDL, and AMG. The results confirm that ICT, renewable energy consumption, and human capital help to bring environmental sustainability in OECD countries. However, the variables globalization, economic growth, and non-renewable energy consumption lead to increase environmental degradation. Finally, it is suggested that investments in the ICT sector must be subsidized to promote online businesses and incentivized through heavy tax relief.
TL;DR: In this article , a review outlined various efficient genetic engineering approaches to promote polyhydroxyalkanoates (PHAs) production and discussed their feasibility in valorizing representative carbon-rich wastes.
Abstract: Polyhydroxyalkanoates (PHAs) are promising biopolymers for biomedical applications due to their excellent biocompatibility and biodegradability. However, the high production cost mainly resulting from the pure sugar substrate limits PHA commercialization. It makes various carbon-rich wastes potential substrates for PHA production. The integration and optimization of metabolic pathways can further enhance the conversion of carbon-rich wastes to PHAs. Genetic engineering strategies focusing on carbon flux and energy metabolism have improved the PHA production capacities of targeted strains by promoting substrate assimilation, enhancing PHA synthesis, and reducing branch metabolism. CRISPR/Cas9-based systems have also served as efficient genome editing tools to improve the efficiency of metabolic modification. Genetic modification requires fitness among strains, substrates, and products. Therefore, this review outlined various efficient genetic engineering approaches to promote PHA production and discussed their feasibility in valorizing representative carbon-rich wastes. To further illustrate the widespread applicability of metabolic modification to support microbial cell factories with core PHA production, this review also involved advanced fermentation approaches and co-production systems for PHA production by engineered strains.
TL;DR: In this article , the effect of an organic substrate on soil properties can be modified towards desired effects using different pre-treatment technologies, suggesting the possibility of “engineer” OAs.
Abstract: Process technologies, such as composting, anaerobic digestion, or lactic acid fermentation, greatly influence the resulting organic amendments (OAs) characteristics even when the same raw material is used. However, it is still unclear how these process technologies indirectly modify the effect of OAs on soil microbial activity and soil aggregation. To determine the effect of OA produced using pre-treatment technologies on the soil microbial activity and soil aggregation, we ran a soil column experiment in which we applied compost, digestate and lactic acid fermentation product made of the same model bio-waste. The results indicated that OAs produced under anaerobic conditions (fermented product and digestate) increased microbial activity, biomass, and soil micro- and macro-aggregation compared to compost and control treatments. Soil microbial activity strongly correlated to C, Ca, Mg, extracellular polymeric substances (EPS), fungal biomass, and macroaggregate formation (rs>0.7, p<0.05). Simultaneously, soil macroaggregate formation strongly correlated to water-extractable C, EPS, cation exchange capacity, K, Mg, Na, and bacterial biomass (rs>0.7, p<0.05). This study demonstrated that the effect of an organic substrate on soil properties can be modified towards desired effects using different pre-treatment technologies, suggesting the possibility of “engineer” OAs.
TL;DR: In this article , the performance of upflow anaerobic sludge blanket (UASB) reactor for stable H2 production from starchy wastewater supplemented with groundnut de-oiled cake using mixed consortia was investigated.
Abstract: The present study investigates the performance of upflow anaerobic sludge blanket (UASB) reactor for stable H2 production from starchy wastewater supplemented with groundnut de-oiled cake using mixed consortia. Insufficient reports are available on H2 production for UASB reactor. Operation of the UASB reactor was divided into two stages i.e., start-up period where desirable sludge height was developed and production period where different hydraulic retention time (HRT) was examined for H2 production. The maximum H2 production rate of 12.3 L L−1 d−1was observed at 3 h HRT. Details physicochemical characteristics of the granular sludge were studied using SEM-EDX image, FTIR spectra, particle size analyser, SVI value, EPS and metal content. Kinetic analysis of the process revealed that Grau, and modified Stover-Kicannon were the most suitable for H2 producing UASB reactor. This is the first report to implement these advanced bio-kinetic models of substrate consumption on hydrogen production in UASB reactor. Furthermore, a potential toward circular bioeconomy model has been discussed for the accomplishment of maximum resource recovery with a minimum waste generation.
TL;DR: In this paper , the authors investigated the effect of various process parameters, including aeration rate, aeration mode and turning frequency, analyzing physicochemical indicators, maturity indicators and gas emissions, to propose comprehensive process parameters that can quickly compost, promote maturity and reduce emissions.
Abstract: Currently, the increasing output of kitchen waste makes its treatment an urgent problem to be solved. Based on the principle of resource utilization, we consider improving various process parameters, including aeration rate, aeration mode and turning frequency, analyzing physicochemical indicators, maturity indicators and gas emissions, to propose comprehensive process parameters that can quickly compost, promote maturity and reduce emissions. The results showed that high aeration rate (> 0.3 L kg −1 DM min −1) reduced the temperature of the matrix and increased the electrical conductivity and germination index of compost, thereby inducing strong emissions of odors and greenhouse gases. Compared with continuous aeration, intermittent aeration was more effective in reducing gaseous emissions under the same total aeration volume but was characterized by lower maturity. Moreover, it was found that non-turning reduced gaseous emissions substantially, while excessively high (once every 2 days) or too low (once every 6 days) turning frequency increased gaseous emissions to varying degrees. Most turning frequencies did not significantly promote compost maturity. The above results indicated that the rapid kitchen waste composting processes that yielded best results were an aeration rate of 0.2∼0.3 L kg −1 DM min −1, continuous or intermittent aeration pattern, and a turning frequency of once every three days. This research was of great significance to the improvement of kitchen waste combined process.
TL;DR: In this article , the removal of a mixture of four veterinary antibiotics (VA) in synthetic wastewater using microalgae-bacteria consortia (MBC) dominated by Scenedesmus almeriensis was studied at different initial concentrations of 1000, 500, 100 and 20 μg/L per antibiotic.
Abstract: The mechanisms involved in the removal of a mixture of four veterinary antibiotics (VA) – tetracycline (TTC), ciprofloxacin (CPF), sulfadiazine (SDZ) and sulfamethoxazole (SMX) – in synthetic wastewater using microalgae–bacteria consortia (MBC) dominated by Scenedesmus almeriensis was studied at different initial concentrations of 1000, 500, 100 and 20 μg/L per antibiotic. Ultra-high performance liquid chromatography and tandem mass spectrometry (UHPLC-MS/MS) were used to determine the removal of the VA for each mechanism. For a hydraulic retention time of 4 days, the overall removal of antibiotics by the MBC was 99.9% for TTC, 78.0% for CPF, 52.6% for SDZ and 5.0% for SMX. A pseudo-first order irreversible model was applied to best fit the experimental data. The degradation constant rates were 0.136 h−1 for TTC, 0.012 h−1 for CPF, 0.010 h−1 for SDZ and 0.0007 h−1 for SMX. Under all the evaluated conditions, CPF and TTC exhibited the highest removal efficiency. Biosorption was the main mechanism for all four antibiotics, followed by biodegradation in the cases of TTC and SDZ. CPF did not show removal via biodegradation. SMX did not show removal via hydrolysis or photolysis. This study (i) integrates and evaluates individually the mechanisms involved in VA removal using an MBC; (ii) determines an overall removal rate constant for a wide array of TTC, CPF, SDZ and SMX concentrations; and (iii) demonstrates the high removal capacity and potential use of microalgae as an ecofriendly wastewater treatment process.
TL;DR: Using red mud (RM) as a carrier, MgO was loaded onto RM by co-precipitation method to prepare an N and P recovery material (MgO-RM) as mentioned in this paper .
Abstract: The struvite method has been widely used to recover N and P from wastewater. However, the drawbacks of alkali consumption and small crystallization are not negligible. Therefore, alkaline porous carrier materials are greatly desired to enhance struvite crystalline precipitation and maintain suitable pH values. In this study, using red mud (RM) as a carrier, MgO was loaded onto RM by co-precipitation method to prepare an N and P recovery material (MgO–RM). A response surface methodology based on the Box–Behnken design was used to explore the effects of the factors on N and P recovery. The multi-objective optimization of the recovery process was carried out using the desirability function approach to achieve an economically feasible recovery. Characterizations, including SEM-EDS, BET, FTIR, XRD, and XPS, were carried out to explore the recovery mechanism. The results demonstrated that the nano-sized MgO was well deposited on the RM surface, resulting in a larger specific surface area and greater reactivity of the MgO–RM. Using RM as a carrier significantly increased the struvite crystal size, and the MgO–RM could maintain the pH value of the solution in a suitable range for struvite growth. Under optimal conditions (dosage = 3.5 g/L, N/P = 1.8, and pH value = 3.4), the maximum N and P recovery capacity by MgO–RM was 57.23 mg/g and 128.05 mg/g. The recovery process may involve coupled reactions between physical adsorption, ion exchange, coordination exchange, and chemical precipitation. Struvite produced by chemical precipitation is the main recovery mechanism.
TL;DR: In this paper , the role of ZnCl2/FeCl 3-rice husk-modified biochar (Zn-BC and Zn/Fe-BC) in treating F−-contaminated surface and groundwater under the influence of varying solution chemistry, coexisting ions, and biochar-amended through column transport experiments was investigated.
Abstract: Fluoride (F−) contamination in water is a global health concern, threatening the well-being of millions. This study investigated the role of ZnCl2/FeCl 3-rice husk-modified biochar (Zn-BC and Zn/Fe-BC) in treating F−-contaminated surface and groundwater under the influence of varying solution chemistry, co-existing ions, and biochar-amended through column transport experiments. Modified biochar showed maximum F− adsorption, 99.01% and 91.90% using Zn/Fe-BC and Zn-BC, respectively, than 85.87% using raw biochar (R-BC). Raw/modified biochars were characterized with FESEM-EDAX, FTIR, XRD, particle size, surface area, electro-kinetic potential, and point of zero charge analyses. Langmuir and pseudo-second-order kinetic could explain that F−-biochar interactions are dominated by chemisorption at ambient temperature while physisorption at higher temperatures. The influence of salt concentrations and co-occurring ions reduced F− sorption using Zn/Fe-BC. Increased salt strengths led to reduced electrophoretic mobility of biochar particles, i.e., biochar-biochar particles attract each other and increase the hydrodynamic diameter, which ultimately reduces the active sites on biochar for fluoride adsorption. Co-transport and deposition of biochar and F− in saturated porous media revealed lower mobility of biochar, and maximum F− adsorption was observed at 10 mM salt strength. Biochar transport is governed by electrostatic interactions, whereas F− transport mainly occurs through chemisorption. In rural areas, hand pumps are generally applied for drinking and cooking; thus, biochar-mediated sand columns can be utilized for defluoridation. Thus, Zn/Fe-BC can be utilized as a potential bio-adsorbent for F−-contaminated natural surface and groundwater with optimum preparation and treatment costs.
TL;DR: In this article , the authors provide the technical assessment and perspective views in optimizing the phytoremediation performance as well as addressing the underlaying issues corresponded to the available post-phyto-mediation treatment disposal and handling methods in order to amplify the commercial value of the whole process as a whole.
Abstract: Phytoremediation is deemed as an efficient and environmentally friendly alternative which utilizes different types of hyperaccumulator plants known as macrophytes for the removal of heavy metal pollutants from water through different mechanisms including phytoextraction, rhizofiltration, phytovolatilization and phytostabilization. The phytoremediation efficiency is affected by several key factors such as plant species (floating, emergent and submerged), surrounding climate (temperature of about 27 °C with sufficient sunlight and water) and environmental conditions (appropriate amount of sodium chloride, nutrients and chelating agents at pH of 5 to 6). The main problem of phytoremediation is the potential secondary pollution due to the re-released of absorbed contaminants by plants which requires utmost attention. The post-treatment disposal and handling methods of post-phytoremediation plants are reviewed extensively. Heat treatment method is able to produce valuable biochemicals at high temperatures range from 160 to 1600 °C. Extraction treatment can extract up to 99 % of heavy metals, while composting requires relatively low energy usage. Synthesis of nanomaterials from phytoremediated plants reduce the usage of hazardous chemicals but hard to be upscaled. Meanwhile, phytomining is economically feasible (saving of up to $8,710 per hectare of crops) but restricted to certain heavy metal treatment. The major hurdle remains in the capability of these methods to achieve great balance between economic viability and environmental impacts. Therefore, the ultimate goal of this paper is to provide the technical assessment and perspective views in optimizing the phytoremediation performance as well as addressing the underlaying issues corresponded to the available post-phytoremediation treatment disposal and handling methods in order to amplify the commercial value of phytoremediation process as a whole.
TL;DR: In this article , a literature review addresses the presence of plastic in domestic wastewater, an increasingly important facet of the widespread use of plastic and its detrimental effects on the environment, with a focus on microplastics (MPs) in sewage sludge and their implications for a circular economy.
Abstract: This literature review addresses the presence of plastic in domestic wastewater, an increasingly important facet of the widespread use of plastic and its detrimental effects on the environment, with a focus on microplastics (MPs) in sewage sludge and their implications for a circular economy. Extensive research has been conducted on the occurrence of MPs in wastewater treatment plants. Sewage sludge is a byproduct of such plants that are widely used in the agricultural and other sectors but may contain emerging contaminants, including MPs, that can pose a significant risk to the environment. The review highlights the high concentrations of MPs in sewage sludge and underscores the need for appropriate disposal methods to prevent soil contamination. MPs can also detrimentally interact with other emerging contaminants, such as heavy metals and organophosphate esters. While extraction technologies exist to remove MPs from wastewater, their implementation is subject to technical and economic considerations. Future research should focus on the optimization and efficacy of these technologies to ensure safe sludge management. Given the high levels of MPs and other emerging contaminants found in sewage sludge, it is crucial to implement technologies that enable sustainable sludge disposal. By acknowledging these challenges and developing appropriate solutions, we can mitigate the environmental impacts of plastic and promote sustainable waste management practices.
TL;DR: In this article , the authors demonstrated a novel technique to achieve partial nitritation/anammox (PN/A) to treat inorganic low-strength wastewater by using a 10 L continuous reactor equipped with fiber carriers.
Abstract: This study demonstrated a novel technique to achieve partial nitritation/anammox (PN/A) to treat inorganic low-strength wastewater by using a 10 L continuous reactor equipped with fiber carriers. Aeration control was the key factor in single-state PN/A performance stability under oxygen-limiting conditions. Intermittent aeration was successfully adapted in this study to achieve over 80% nitrogen removal at the nitrogen loading rate of 0.12–0.16 kg N m−3 d−1. The nitrite-oxidizing bacteria activities were inhibited by intermittent aeration due to the alternate between aerobic to anoxic conditions. Ammonium-oxidizing bacteria (AOB) and anammox bacteria could be symbiotically supported within the biofilm with a specific activity of anammox bacteria that was 1.5 times higher than that of AOB. The biomass was efficiently retained by using fiber carriers. The results obtained from this study could bring the possibility of applying an energy-saving and efficient biofilm single-stage PN/A process in tropical regions.
TL;DR: In this paper , a review of the recent progress in the fabrication of porphyrin-based nanomaterials via self-assembly, their properties, and their applications in environmental treatment and sensing is presented.
Abstract: Functionally designed structures mimicking natural mechanisms can be obtained via supramolecular self-assembly of porphyrin derivatives. Porphyrin-based nanomaterials obtained via self-assembly can be utilized in several applications, such as optical energy or information storage, solar energy conversion, sensors, nanocatalysts, photoelectronics, and photodynamic therapy. In recent years, the fabrication of porphyrin nanostructures via self-assembly for sensing and environmental remediation has attracted extensive interest from scientists, making it an essential aspect of the research field. This review outlines the recent progress in the fabrication of porphyrin-based nanomaterials via self-assembly, their properties, and their applications in environmental treatment and sensing. It begins with introducing porphyrin and the self-assembly method to fabricate porphyrin nanomaterials. Porphyrin nanostructures can be fabricated via self-assembly, including the re-precipitation, coordination polymerization, ionic self-assembly, and other methods, are discussed. Finally, possible applications of porphyrin-based nanomaterials focusing on environmental remediation, sensing, hydrogen production, targeted and imaging therapy, and CO2 reduction are presented with highlights from recent studies in this field.