Protected areas (PAs) are the major conservation tool for ecosystem conservation, but function unequally in mitigating human pressures in practice. Assessing PA vulnerability caused by human pressures and its association with socioeconomic and PA characteristic factors is vital for improving conservation effectiveness and the post-2020 PA expansion. Here, using a new framework integrating the intensity and temporal changes of human pressures in PAs and their matched unprotected areas, we categorize global terrestrial PAs into four anthropogenic vulnerability levels: high (11.7 %), moderate (18.6 %) and low (21.9 %) vulnerability and wilderness (47.8 %). We find significant variations in the anthropogenic vulnerability of PAs between countries, continents, and IUCN categories. Europe has the highest proportion of high-vulnerability PAs (ca. 19.7 % of protected areas in Europe), while South America and Oceania have the highest proportions of low-vulnerability PAs and wilderness PAs, respectively (33.2 % and 75.0 % respectively). The vulnerability of PAs is not significantly associated with socioeconomic factors at the country level, which might reflect the trade-offs between positive and negative outcomes of development. With a new framework that integrated four significant factors for anthropogenic vulnerability assessment, this study demonstrates that global PAs have different anthropogenic vulnerability levels and suggest that some PAs function effectively in mitigating human pressures despite currently intense human pressures within them. Our results also suggest that future evaluations on the conservation status should pay attention not only to PA coverage but also to the anthropogenic vulnerability levels within PAs to achieve higher conservation effectiveness.
Manganese oxides (MnOx) are recognized as a strongest oxidant and adsorbent, of which composites have been proved to be effective in the removal of contaminants from wastewater. This review provides a comprehensive analysis of Mn biochemistry in water environment including Mn oxidation and Mn reduction. The recent research on the application of MnOx in the wastewater treatment was summarized, including the involvement of organic micropollutant degradation, the transformation of nitrogen and phosphorus, the fate of sulfur and the methane mitigation. In addition to the adsorption capacity, the Mn cycling mediated by Mn(II) oxidizing bacteria and Mn(IV) reducing bacteria is the driving force for the MnOx utilization. The common category, characteristics and functions of Mn microorganisms in recent studies were also reviewed. Finally, the discussion on the influence factors, microbial response, reaction mechanism and potential risk of MnOx application in pollutants’ transformation were proposed, which might be the promising opportunities for the future investigation of MnOx application in wastewater treatment.
In this study, Mn-C composites using different MnO2 contents and solid carbon material were prepared to explore the synchronous removal performance of nutrients and SMX. Higher nitrate removal performance (97-98 %) with quickest nitrate removal rate (4.97 mg N L -1h- 1) was obtained in Mn\_20 systems. The increased Mn content and Mn-P compound were observed via surface characteristics, indicating the involvement of MnOx in pollutants removal, particularly for higher phosphorus removal (84-89 %) via Mn-P precipitation and BioMnOx adsorption. Nevertheless, compared to systems based on Mn\_0 composites (74 %), systems with Mn-C composites presented lower SMX reduction efficiency (34-51 %), which might be attributed to the large Mn(II) accumulation, impairing certain microbes and lower the MnOx function. Higher abundance of genera affiliated to Bacter-oidetes\_vadinHA17 and Rhodocyclaceae was observed in the Mn-C composites, as well as the gathering of Geo-bacter and Desulfovibrio as keystone taxa, responsible for the removal of nitrate and SMX and microbial interactions. Besides, the increase of sulfonamide ARGs was closely related to the predominant microbes in the Mn-C composites, which acted as the hosts of ARGs. This study broadens the knowledge of Mn-C composites in synergetic removal of nutrients and organics, and supports the potential application of manganese oxide in wastewater treatment.
The urban infrastructures of municipal solid waste (MSW) disposal play important roles in carbon reduction and building sustainable cities. China, with the world's largest MSW generation, has witnessed a relatively slow and spatially uneven transition progress of MSW disposal management. This study analysed the MSW disposal management transition and its determinants in Chinese cities of different sizes. Furthermore, the carbon reduction potential of MSW disposal management transition was estimated under different settings of policy reform. The results indicate that the MSW disposal management transition has made faster progress in cities with larger sizes, which could be ascribed to larger contradiction between city development and public service. The prediction results suggest that 73.13%–287.28% of carbon emission could be reduced by various policy reforms compared with the baseline scenario without policy intervention. Moreover, technological transformation should be specially underlined in mega cities, and household sorting should be specially underlined in medium cities.
As novel photocatalysts, covalent organic frameworks (COFs) have potential for water purification. Insufficient exciton dissociation and low charge mobility in COFs yet restricted their photocatalytic activity. Excitonic dissociation and charge transfer in COFs could be optimized via regulating the donor–acceptor (D–A) interactions through adjusting the number of donor units within COFs, yet relevant research is lacking. By integrating the 1,2,4-triazole or bis-1,2,4-triazole unit with quinone, we fabricated COF-DT (with a single donor unit) and COF-DBT (with double donor units) via a facile sonochemical method and used to decontaminate emerging contaminants. Due to the stronger D–A interactions than COF-DT, the exciton binding energy was lower for COF-DBT, facilitating the intermolecular charge transfer process. The degradation kinetics of tetracycline (model contaminant) by COF-DBT (k = (12.21 ± 1.29) × 10–2 min–1) was higher than that by COF-DT (k = (5.11 ± 0.59) × 10–2 min–1) under visible-light irradiation. COF-DBT could efficiently photodegrade tetracycline under complex water chemistry conditions and four real water samples. Moreover, six other emerging contaminants, both Gram-negative and Gram-positive strains, could also be effectively eliminated by COF-DBT. High tetracycline degradation performance achieved in a continuous-flow system and in five reused cycles in both laboratory and outdoor experiments with sunlight irradiation showed the stability and the potential for the practical application of COF-DBT.
With the developing technologies of artificial intelligence and the Internet of Things, intelligent IoT (iIoT) is prevailing currently. Design and implementation of integrated IoT nodes with continuous perception capability are indispensable to realize various smart terminal devices, which would also be vital to reduce the power consumption, improve the real-time performance, and enhance the security/privacy of the IoT system. In this paper, we present the architecture of “Sensing with Computing” and its chip design for smart sensing applications, which would support multi-modal perception signal processing with multi-dimension extension ability. Specially, we explore the analog/mixed-signal circuit designs and algorithm-hardware co-design methodologies for perception signal processing, and we also study the multi-modal integration of novel sensors and their interface technologies. Additionally, some multi-modal smart sensing systems with “Sensing + Computing in Memory” mixed-signal chips would be fabricated, which would support typical always-on smart sensing tasks.
Halogenated pharmaceuticals exhibit high toxicity if released to natural environment, and dehalogenation is a key process for their degradation. In this study, a reductive and directional dehalogenation technique, heterogenous formic acid (HCOOH) catalytic activation system, was proposed for diclofenac (DCF) dechlorination and detoxification. A functional material of Pd nanocluster decorated graphitic carbon nitride (Pd/g-C3N4) was developed for HCOOH activation. Although the optimized material (Pd1/g-C3N4) showed lower HCOOH decomposition rate (k1 = 0.287 ± 0.017 min−1) than the pristine Pd particles (k1 = 0.401 ± 0.031 min−1), it processed higher DCF degradation efficiency (97.9% within 30 min) than Pd particles. The enhancement mechanism was revealed by both experiments and theoretical calculations. Firstly, the six-fold cavities of g-C3N4 acted as anchor sites, which offered strong coordination environment for Pd nanoclusters. Secondly, the strong coordination environment of Pd led to upshifted d-band center of Pd 4d with enhanced bonding state, and then promoted HCOOH adsorption on Pd/g-C3N4, thus facilitating HCOOH decomposition through formate pathway rather than carboxyl pathway. Thirdly, Pd/g-C3N4 ensured HCOOH selectively decomposed as dehydrogenation reaction, which generated more H* (adsorbed H on Pd) than the dehydration reaction. The H* was proved to be the dominant reductive species for DCF hydrodechlorination. Moreover, the toxicities of DCF dechlorination products were greatly reduced.