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Phytoremediation is an in situ environmentally friendly and economically feasible remediation technology to treat heavy metal contaminated soil.

This study quantitatively evaluated the effects of pyrethroid pesticides on the testis of male rats. An extensive literature search for relevant studies was conducted on PubMed, Web of Science, Excerpta Medica Database, the Chinese National Knowledge Infrastructure, and Chinese Biomedical Literature Database. Pooled standard mean difference with corresponding 95% confidence interval was calculated via the random-effects model. I 2 was used to evaluate heterogeneity among studies. A total of 19 studies were included for analysis in our study. Results indicated that the sperm count of rats exposed to fenvalerate was lower than that of rats in control groups. The sperm count, sperm motility, and testosterone level of rats exposed to cypermethrin and deltamethrin were lower than those of rats in control groups. Moreover, the sperm morphology of rats exposed to these pyrethroid pesticides was abnormal compared with that of rats in control groups. The present meta-analysis indicates that pyrethroid pesticides decrease rat sperm count, sperm motility, and testosterone level and cause abnormal rat sperm morphology. Therefore, pyrethroid pesticides can damage the testis of male rats.

Excellent triboelectric charge density and hydrophobicity are achieved on cellulose nanofibrils (CNFs) by employing a simple and environmentally friendly approach to aminosilane modification of a C...

The digital twin-based manufacturing system is a typical representative of smart manufacturing and has a number of advantages beyond the state of the art. However, when a manufacturing syst...

Activated sludge treated by ultrasound was tested as a source of exogenous electron donor to accelerate quinoline mono-oxygenation, which requires an intracellular electron donor (2H). The quinoline-removal rate was proportional to the amount of treated or untreated sludge added in flask experiments, but the best biodegradation kinetics was obtained with a mixture of 25% untreated sludge plus 75% treated sludge. The treated sludge primarily provided exogenous electron donor, while the untreated sludge provided active biomass. A biofilm system also showed the same beneficial effect of treated sludge, and the soluble fraction of the treated sludge had the greatest impact. Using treated sludge instead of a purchased electron donor provides an economic advantage for accelerating the biodegradation of contaminants whose biodegradation is initiated by an oxygenation reaction, such as quinoline.

Fallen leaves of Platanus orientalis and Ginkgo biloba linn were separately immersed in water to obtain leachates that were used as exogenous electron donors for accelerating pyridine and quinoline biodegradations. Leachate addition accelerated the pyridine removal rate by up to 4.4% and 3.6% and the quinoline removal rate by 9.5% and 11%. The rates increased further after the leachates were illuminated by UV light: up to 8.5% for pyridine and 12% for quinoline. Succinate and oxalate were separately added into solutions of pyridine and quinoline (respectively) to gauge the acceleration impact of the leaf leachates. Equations describing the relationships between addition of leachate and pyridine or quinoline removal rates were established based on electron-equivalent balances and comparison to the acceleration effects from succinate and oxalate. From 22% to 98% of the COD leached from leaves was available as an electron donor, with the fraction being greater for pyridine and after UV illumination.

Lignocellulosic biomass is the most abundant renewable resource on the earth. With the development of related fields, the high value utilization of lignocellulosic biomass has gradually become a new avenue for research. In this study, unbleached bagasse pulp was pretreated with xylanase and cold alkali to partially remove hemicellulose and convert to some cellulose I into cellulose II. Cellulose nanofibrils (CNF) were then obtained through ultra-micro grinding and high-pressure homogenization. The prepared CNF were characterized by TEM, Zeta potential, ATR-FTIR and XRD, and a thermogravimetric analyzer was used to analyze the thermal stability of CNF. The results show that xylanase pretreatment can improve the dispersion of fibers during mechanical treatment and can enhance the crystallinity of CNF. With an increase in alkali concentrations, the proportion of cellulose II structures increased, while cellulose crystallinity levels decreased due to the folding of cellulose chains. Under the common influence of crystallinity and crystal structures, the thermal stability of the CNF prepared after cold alkali pretreatment underwent an increasing trend. This shows that the influence of crystal structures on the thermal stability of CNF gradually plays a dominant role as alkali concentrations increase.

Para-nitrophenol (PNP) is often detected in industrial wastewater that is discharged into municipal wastewater treatment plants. Intermittent discharge of PNP into municipal treatment facilities puts their biological process at risk of inhibition, and the risk is especially great for nitrification. In this work, nitrifying biomass was acclimated to PNP. The acclimated biomass retained most of its ammonium-removal activity when it was exposed to PNP at up to 100 mg/L, while the normal (unacclimated) biomass had nearly complete inhibition. PNP was effectively biodegraded by the acclimated biomass, but the normal biomass had minimal PNP biodegradation. After PNP disappeared, the acclimated biomass recovered its ability for NH4+-N removals within one to two days, but the normal biomass did not fully recovery even after seven days. The acclimated biomass had superior ability to sustain nitrification due to its ability to biodegrade PNP and its selection of nitrifying bacteria more resistant to PNP. The PNP-acclimated community was enriched in genera that could have been active in the biodegradation of PNP, such as Chloroflexi. Although the abundance of well-known nitrifiers, Nitrosomonas and Nitrospira, decreased, Nitrosospira and other genera within the Proetobacteria phylum increased, presumably because they were more resistant to PNP.

Bamboo rats (Rhizomys sinensis) are widely farmed in Guangdong, China, but the distribution and public health potential of Cryptosporidium spp. in them are unclear. In this study, 724 fecal specimens were collected from bamboo rats in Guangdong Province and analyzed for Cryptosporidium spp. using PCR and sequence analyses of the small subunit rRNA gene. The overall detection rate of Cryptosporidium spp. was 12.2% (88/724). By age, the detection rate in animals under 2 months (23.2% or 13/56) was significantly higher than in animals over 2 months (11.2% or 75/668, &chi, 2 = 6.95, df = 1, p = 0.0084). By reproduction status, the detection rate of Cryptosporidium spp. in nursing animals (23.1% or 27/117) was significantly higher than in other reproduction statuses (6.8% or 4/59, 2 = 7.18, df = 1, p = 0.0074). Five Cryptosporidium species and genotypes were detected, including Cryptosporidium bamboo rat genotype I (n = 49), C. parvum (n = 31), Cryptosporidium bamboo rat genotype III (n = 5), C. occultus (n = 2), and C. muris (n = 1). The average numbers of oocysts per gram of feces for these Cryptosporidium spp. were 14,074, 494,636, 9239, 394, and 323, respectively. The genetic uniqueness of bamboo rat genotypes I and III was confirmed by sequence analyses of the 70 kDa heat shock protein and actin genes. Subtyping C. parvum by sequence analysis of the 60 kDa glycoprotein gene identified the presence of IIoA15G1 (n = 20) and IIpA6 (n = 2) subtypes. The results of this study indicated that Cryptosporidium spp. are common in bamboo rats in Guangdong, and some of the Cryptosporidium spp. in these animals are known human pathogens.

One of the globe environmental issues arising from pesticides loss due to sprayed droplets bouncing and rain washing causes severe soil and groundwater pollution. This issue can be tackled by enhancing the deposition of agrichemical sprays and their retention on plant surfaces, which has been proved extremely challenging. Here, we present an eco-friendly system made of surface-modified nanofibres derived from natural lignocellulosic biomass to improve pesticide utilization efficiency via multiple mechanisms. The addition of soft condensed matter polymer cellulose nanofibres (CNFs) could enhance the deposition of droplets on the hydrophobic surface due to the change of rheological properties of the suspension as observed by a high-speed camera. Cationization of CNFs was further proven to enhance the adhesion between droplets and negatively charged plant leaf surfaces via electrostatic interactions. As a result of the combined above effects, the retention rate of fluorescent markers could reach 80% after the rain washing test. In addition, lignin-containing CNFs were also investigated for their capability to protect photosensitive pesticides, whose retention rate increased by 150% due to the anti-UV property of lignin. Quaternized CNFs also enhanced the anti-pest effect of pesticides. Overall, biodegradable and multifunctional CNFs from lignocellulosic biomass were fabricated via relatively simple surface modification and used as additives to sufficiently improve the utilization of pesticides, realizing a sustainable circular economy concept in the agricultural field.

Many municipal wastewater treatment plants in China receive industrial wastewater that contains inhibitory organic chemicals, such as chlorinated phenols. For the common aerobic biological treatment, nitrification is a key step, but nitrifying bacteria are notably sensitive to inhibition by chlorinated phenols. In this work, normal activated sludge (containing nitrifying biomass) was acclimated to 2,4,6-trichlorophenol (TCP). The acclimated biomass had more than 2-fold faster nitrification kinetics than normal biomass when exposed to TCP, and it also achieved effective TCP removal in parallel. When suddenly exposed to TCP after as much as two months without TCP input, the acclimated nitrifying biomass retained effective nitrification and TCP biodegradation: The nitrification rate and TCP removal rate were 0.325 mM/h and 0.049 mM/h for the acclimated biomass, compared to only 0.165 mM/h and 0.001 mM/h for normal biomass. Resistance to TCP inhibition also was retained for 5 generations of sub-culturing without TCP exposure. High-throughput sequencing confirmed that the acclimated biomass contained nitrifying bacteria and heterotrophic bacteria capable of degrading TCP, although the key genera changed during sub-culturing.

The active hydrogen maser is a core piece of equipment for the time-frequency system. Its stability and reliability directly influence system performance. The optimization of temperature coefficients for physical and circuit systems provides a direct means to further improve performance of active hydrogen masers. Based on the existing sapphire active hydrogen maser, the microwave cavity, magnetic shield, and other components of its physical package have been optimally designed, resulting in new dielectric-loaded cavity and full-size cavity, with a temperature coefficient of −10 kHz/℃ and −1 kHz/℃, respectively. Taking into account the two newly designed cavities, we have achieved active hydrogen masers with volume in completely two different directions. The hydrogen maser with a dielectric-loaded cavity achieved a stability of 2.1E-13/1s and 2.3E-15/d, and that with a full-size cavity achieved a stability of 1.5E-13/1s and 1.6E-15/d when cavity servo system was not installed. The physical package of the active hydrogen maser with a dielectric-loaded cavity can achieve a size of Φ220 mm × 500 mm, and this technical solution is the best choice for space applications.

With advances in biotechnology, enzyme technologies have been increasingly applied to pretreat lignocellulosic biomass before the production of pulp. There are several driving forces, which include decreasing environmental impact from the traditional pulp and paper manufacturing processes, decreasing the overall production cost, and improving the product properties. This paper reviews recent developments in the area, particularly, related to the production of bleached pulp, dissolving pulp and pulp refining. This paper focuses on the mechanism and influencing factors of enzymatically assisted pulp bleaching to reduce adsorbable organic halide (AOX) formation and dissolving pulp production and focuses on saving energy in pulp refining. The enzyme technology is in the marketplace of the pulp and paper processes, and it is expected to gain more importance in the future.

The influence of enzymatic treatment on the thermal stability of cellulose nanofibrils (CNFs) was investigated. The unbleached bagasse pulp was treated with different dosages of xylanase, and samples were taken at different grinding stages. The produced CNF were characterized by Malvern Zetasizer, TEM, ATR-FTIR and XRD, and the thermal stability of the CNF was evaluated using TGA. The mechanism of enzymatic treatment on the thermal stability of CNF was proposed. The results indicated that all the diameters of produced CNF were

It is common that phenol and quinoline co-exist in the same industrial wastewater, such as coking wastewater. For both biodegradations, the initial steps are mono-oxygenation reactions, which require two co-substrates: molecular oxygen (O2) and an intercellular electron donor (2H). Competition for O2 and 2H was investigated using a vertical baffled bioreactor (VBBR) with a biofilm acclimated to phenol and quinoline biodegradation. Batch experiments documented mutual inhibition between phenol and quinoline, which competed for O2, 2H, or both during simultaneous biodegradation. Low DO was a limiting factor for phenol and quinoline biodegradations, as both rates slowed significantly for DO ≤ 3 mg/L, compared to DO ≥ 5 mg/L. A DO concentration of 0.5 mg/L led to 89% and 65% slower removal kinetics for phenol and quinoline, respectively. Although adding succinate as an exogenous electron donor was able to alleviate competition when the DO was 4 ∼ 5 mg/L, it had no benefit for a DO ≤ 3 mg/L. Thus, significant DO limitation could not be overcome by addition of more donor. The results imply that a strategy that involves adding or creating an exogenous electron donor may be effective only when DO is not significantly rate limiting for the initial oxygenation reactions.

The trajectory similarity join aims to find similar trajectory pairs from two large collections of trajectories. This join targets applications such as trajectory near-duplicate detection, ridesharing recommendation and so on. Extensive works have been conducted on addressing this join. However, most of them only focus on spatial dimension without combining temporal range together. To address problem, this paper proposes a novel two-level grid index which takes both spatial and temporal range into account when processing spatial-temporal similarity join, and signature based dynamic grid warping (SDGW) approach to evaluate the spatial similarity for trajectory pairs. Some pruning approaches are developed to improve the query processing. In addition, extensive experiments are conducted to verify the efficiency and scalability of our methods.

Cellulose is the most abundant natural polymer on earth. Because it is renewable, biodegradable, and biocompatible, it offers distinct advantages as a starting material for bio-based triboelectric nanogenerator (bio-TENG). However, weak polarity, poor hydrophobicity, and insufficient functionalization on the natural cellulose surface severely limit the development of high-performance cellulose-based TENGs. In this work, chemical functionalization is employed to control the surface polarizability and hydrophobicity of cellulose nanofibrils (CNFs). Functional groups on the CNF surface are modified with triethoxy-1H,1H,2H,2H-tridecafluoro-n-octylsilane (PFOTES) in a straightforward and facile process. Fluorine-bearing silane chains are grafted to the surface of CNFs, which increases their triboelectric charge density and improves their hydrophobicity. Experimental results demonstrate that the surface polarity of CNFs is greatly improved after PFOTES modification. The PFOTES-CNF-based TENG exhibits good resistance to humidity and long-term cycle stability, and it retains 70% of the initial output performance at 70% ambient humidity. The short-circuit current of the PFOTES-CNF-based TENG reached 9.3 μA, which is about twice that of CNF-based TENG prior to modification. These results clearly indicate that PFOTES can be used to control CNF surface polarizability and hydrophobicity, advancing the search for durable, high-performance, degradable bio-TENGs.

In recent years, air pollution has detrimentally affected human health. Particulate matter (PMx) is a primary component of air pollution, and significant research effort has been devoted to developing feasible technologies for its removal. In this study, a radial piston triboelectric nanogenerator (RP-TENG) enhanced cellulose fiber air filter (CFAF) was developed to remove PMx from outdoor ambient air. This self-powered PMx removal system can not only convert rotating mechanical energy into electrical energy, but it can automatically remove polluted air from the outdoor environment. After charging, the removal efficiency of the CFAF was 83.78% for PM2.5 and 86.82% for PM10, which were 1.21 times and 1.27 times greater than those of the uncharged system, respectively. The self-powered PMx removal system can be installed on an object with rotating mechanical energy, such as the rotating shaft of a shared bicycle, and the wasted rotating mechanical energy would be used to fully purify the outdoor environment. Furthermore, this system is environmentally friendly due to its low level of carbon emissions. This work has numerous potential applications as it provides a new and sustainable strategy for applying self-powered, TENG-enhanced air filters for the removal of PMx from outdoor air.

Aerobic biomass (acclimated activated sludge) was treated by ultrasound and used to accelerate biodegradations of pyridine and p-nitrophenol (PNP), which begin with mono-oxygenation reactions that need an internal electron donor. Ultrasound treatment disrupted the biomass and produced more soluble and (especially) colloidal organic material. Compared with untreated biomass, pyridine- and PNP-biodegradation rates increased when treated biomass provided electron donor. Pyridine- and PNP-biodegradation rates increased by 10% and 20%, respectively, over the control experiments when supernatants from treated biomass were added into the medium. For accelerating pyridine- and PNP removal rates, adding supernatants of treated biomass was equivalent to adding succinate of 0.35 mmol/L and 0.21 mmol/L, respectively. The rates were increased by 63% for both substrates when the entire treated biomass was added. Colloidal solids in the treated biomass contained most of biodegradable electron donor able to stimulate initial monooxygenations of pyridine and PNP. Adding treated biomass together with untreated biomass gave a synergistic impact on enhancing pyridine and PNP biodegradation, because the treated biomass supplied extra donor, while the untreated biomass maintained a high level of active biomass.

Cellulose is the most abundant natural polymer with low cost, high strength, good chemical modification property and biodegradability. In this work, a cellulose-based triboelectric material is prepared by surface amino modification and silver nanoparticle coating treatment of cellulose nanofibrils (CNFs), and a novel and simple CNF-based gear-like triboelectric nanogenerator (TENG) is designed. The three-dimensional space structure increases the frictional contact area by approximately four times compared with an ordinary planar structure. This gear-like structure shows good flexibility and integration, and the maximum open-circuit voltage can reach 286 V when three pairs of gear-like structures are assembled. The maximum power density is 0.43 W/m2 with a load resistance of 5 × 107 Ω, and the resulting electrical output can directly power 60 light-emitting diodes. Moreover, TENG exhibits exceptional sensitivity and responsiveness when used as a self-powered sensor. It can reflect the change in the state of human touch through electric signals and also respond to the changes in small forces caused by water drop and vibration in the substrate. This study not only introduces a green CNF-based triboelectric material, but also presents for the first time a high-performance TENG with a gear-like structure and applies it to self-powered sensing.

It is common that biological wastewater-treatment processes are exposed to inputs of toxic compounds, such as phenolics. Due to their slow growth rate, nitrifying bacteria are most susceptible to inhibition that can lead to loss of nitrification capacity. Here, a microbial community containing nitrifying bacteria was acclimated to phenol, and it developed resistance to phenol inhibition and maintained nitrification activity. For the phenol-acclimated biomass, the NH4+-N removal rates were almost unaffected when it was suddenly exposed to phenol. Heterotrophic synthesis and nitrification rates contributed 76% and 24% of the total NH4+-N removal respectively during phenol removal, but the nitrification rate increased significantly once phenol was removed and mineralized. In contrast, the NH4+-N removal rates decreased sharply for normal (unacclimated) nitrifying biomass when it was exposed to phenol. The phenol-acclimated biomass retained its resistance to phenol inhibition for at least two months after acclimation, and addition of the phenol-acclimated biomass to the normal biomass conferred resistance to phenol inhibition. Community analysis of the phenol-acclimated biomass showed an increase in families known to contain strains able to biodegrade phenolics. Taken together, the results indicate that the main impact of phenol acclimation was enrichment of phenol-biodegrading bacteria, which allowed rapid removal and mineralization of phenol and, consequently, alleviation of phenol's inhibition of nitrification.

Aerobic biodegradation of nitrobenzene (NB) produces nitrophenol (NP), which has stronger toxicity than NB. Anaerobic biodegradation of NB produces aniline (AN), which has weaker toxicity, but is a dead-end product in anaerobic conditions. Accumulation of AN should be overcome by coupling anaerobic and aerobic transformations: NB is transformed to AN in an anaerobic zone of the bioreactor, and AN is then transformed in an aerobic zone. A vertical baffled bioreactor (VBBR) was employed for NB biodegradation with a controlled dissolved oxygen (DO) concentration. NB biodegradation was accelerated by simultaneous anaerobic and aerobic transformations, since AN was biotransformed by a mono-oxygenase reaction. Adding exogenous electron donor (acetate) enhanced NB removals when the DO concentration was ∼0.5 mg/L, because the donor accelerated mono-oxygenations of NB and AN. Coupling anaerobic and aerobic transformations can be a valuable strategy for biodegrading organic compounds that undergo aerobic and anaerobic biotransformations.

In the present study, cellulose nanofibrils (CNF) were produced from unbleached eucalyptus pulp, and the effect of enzymatic treatment on the properties of CNF was studied. Moreover, the mechanism of enzymatic treatment on the dispersion and film properties of CNF was speculated. The xylanase pretreatment facilitated the deconstruction of pulp into CNF via mechanical shearing and high-pressure homogenization, while the hemicellulose composition was preserved. Compared to the control, the CNF suspensions made from the xylanase pretreated pulp were more crystalline with higher dispersion, optical and rheological properties. CNF films were produced with a vacuum filtration process. The optical and mechanical strength properties of the CNF films were improved by the removal of hemicellulose. It was found that the carboxyl and hydroxyl groups played key roles in affecting the dispersion and film properties of the CNF. The carboxyl group content increased after the enzymatic pretreatment, which benefits the even distribution of CNF in water. The mechanical strength of the CNF films was further improved by exposing the hydroxyl group when lignin-carbohydrate complexes were de-structured by the enzymes. This study expanded the application of CNF produced from unbleached pulp. The theoretical foundation for stabilizing the CNF suspension and the high-speed dehydration of CNF films were explored for the continuous roll to roll production of CNF film.

In this paper we propose a novel multiple target tracking model composed of two detectors and a tracker. An on-line detector and a tracker are used to generate target candidates, whose confidence scores are then evaluated by the off-line trained detectors. In the data association stage, the high-efficient inference in a structural model leads to the optimal tracking result. The experimental results demonstrate that our tracking model can overcome the occlusion and appearance changing problems. The tracking results can be applied to analyze the structural information of a single target or among multiple targets.

Foreground extraction and moving object detection are often used in human tracking systems. However those methods are not able to produce accurate results when objects are too close or when occlusions happen since the result is generally a single big blob which contains all the different objects. In this paper we propose a novel and efficient moving object detection enhancement method. Indeed, by using the results of the previous iteration tracking we are able to keep a correct number of moving objects by removing useless blobs and by splitting those which contain more than one tracker. The method can also speed up the tracking by creating a link between a tracker and a blob to avoid unnecessary processing in some situations.

Weather such as rain and snow cause difficulties in processing the videos captured. Since the appearance of rain drops can affect the performance of human tracking and reduce the efficiency of video compression, detection and removal of rain is a challenging problem in outdoor surveillance systems. In this paper, we propose a new algorithm for rain detection, which is based on joint spatial and wavelet domain features. This approach is robust to the videos with moving objects in the rain. Experimental results demonstrated its better performance in comparison with the existing approaches in the subjective quality.