查看更多>>摘要：Biodiversity conservation plays an important role in the sustainable development of human society.China had made significant progress in biodiversity conservation studies and practices.This paper reviews major achievements in China in the past decades,especially those since 2010.In terms of the science behind biodiversity conservation,Chinese scholars have made significant contributions to priority research subjects,including mechanisms for maintaining biological communities and the relationship between biodiversity and ecosystem functioning.Simultaneously,biodiversity conservation and management systems specific to China have been basically established.The Chinese Government and researchers have undertaken a number of investigations,scientific studies,and monitoring,and have established relevant databases.With efforts taken to protect and restore biodiversity and ecosystems,the concept of biodiversity has gradually become popular in China.This review is an attempt to share with the world the learning from China's progress towards becoming an ecological civilization and highlights that the efforts towards biodiversity conservation need to be organically integrated with sustainable development goals.
查看更多>>摘要：Formation of acid mine drainage (AMD) is a widespread environmental issue that has not subsided throughout decades of continuing research.Highly acidic and highly concentrated metallic streams are characteristics of such streams.Humans,plants and surrounding ecosystems that are in proximity to AMD producing sites face immediate threats.Remediation options include active and passive biological treatments which are markedly different in many aspects.Sulfate reducing bacteria (SRB) remove sulfate and heavy metals to generate non-toxic streams.Passive systems are inexpensive to operate but entail fundamental drawbacks such as large land requirements and prolonged treatment period.Active bioreactors offer greater operational predictability and quicker treatment time but require higher investment costs and wide scale usage is limited by lack of expertise.Recent advancements include the use of renewable raw materials for AMD clean up purposes,which will likely achieve much greener mitigation solutions.
查看更多>>摘要：Methane emissions and plastic pollution are critical global challenges.The biological conversion of methane to poly-β-hydroxybutyrate (PHB) not only mitigates methane emissions but also provides biodegradable polymer substitutes for petroleum-based materials used in plastics production.This work provides an early overview of the methane-based PHB advances and discusses challenges and related strategies.Recent advances of PHB,including PHB biosynthetic pathways,methanotrophs,bioreactors,and the performances of PHB materials are introduced.Major challenges of methane-based PHB production are discussed in detail;these include low efficiency of methanotrophs,low gas-liquid mass transfer efficiency,and poor material properties.To overcome these limitations,various approaches are also explored,such as feast-famine regimes,engineered microorganisms,gas-permeable membrane bioreactors,two-phase partitioning bioreactors,poly-β-hydroxybutyrate-co-hydroxyvalerate synthesis,and molecular weight manipulation.
查看更多>>摘要：In recent years,Cylindrospermopsis raciborskii blooms have been widely found worldwide.Topics dealing with the mitigation of C.raciborskii bloom is of great importance for toxins produced could threaten public health.The paper first investigated C.raciborskii dynamics over three years following sediment dredging in a shallow eutrophic Lake Dongqian (China).Based on rpoC1 gene copies,C.raciborskii bloom formed with average density of 1.30 × 106 cells/L on July 2009.One year later after sediment dredging,C.raciborskii cell density decreased below 1.17 × 105 cells/L or under detected limits during summer days on 2010.While two years later,the C.raciborskii bloom period was returned with markedly increased cell density reaching up to 4.15 × 107 cells/L on October 2011,and the maximum peak density was shown at 20.3 ℃ that was much lower than reported optimal growth temperature.Inferred from Spearman correlation analysis,linear regression showed C.raciborskii density was significant and positive with pH and SD,whereas they were significant and negative with TP and DO.Multiple regression analysis further demonstrated that TN,TP,SRP,pH and DO provided the best model and explained 53,1％ of the variance in C.raciborskii dynamics.The approaches managing nutrients reduction might not control C.raciborskii bloom as extremely low TN (avg.0.18 mg/L) and TP concentrations (avg.0.05 mg/L) resulted in the highest C.raciborskii cell density after sediment dredging.
查看更多>>摘要：Particulate-associated trace metals have been regarded as an important pollution source for urban surface runoff.Cd,Pb,Cu,Zn and total solids (TS) washed off two different surfaces (low-elevated facade and road surfaces) under two kinds of antecedent environmental conditions (dry and snow-melting) were determined in this study.Wet-vacuuming sweeping (WVS) and surface washing (SW) methods,representing the maximum pollution potential and common rainfall-induced wash-off condition respectively,were used to collect the particulate matters.The result shows that the wash-off concentrations of trace metals were found in the order of Cd (2.28 ± 2.08 μg/l) ＜ Pb (435.85 ± 412.61 μg/l) ＜ Cu (0.93 ± 0.61 mg/l) ＜ Zn (2.52 ± 2.30 mg/l).The snow-melting process had a considerable influence on the wash-off concentrations of the trace metals on both road and facade surfaces.It reduced ＞38％ and ＞79％ of metals and TS concentrations in the facade surface and road surface runoff respectively.The wash-off concentrations of Cd,Cu,and Zn on the road surface 45-780％ higher than those on the facade surfaces.The sensitivity analysis based on the Bayesian network indicates that the wash-off concentrations of metals were mainly dependent on the antecedent environmental conditions or the surface properties while the sampling methods had a minor influence.Therefore,to accurately model the pollutant migration in the surface runoff requires an improving method considering different surfaces and antecedent environment conditions.
查看更多>>摘要：Heterotrophic nitrification-aerobic denitrification (HNAD) is essential in diverse nitrogen-transforming processes.How HNAD is modulated by quorum sensing (QS) systems is still ambiguous.The QS system in Pseudomonas aeruginosa manipulates colony behavior.Here,we described the influence of the Pseudomonas quinolone signal (PQS) and N-acyl-t-homoserine lactone (AHL) on HNAD.The HNAD of P.aeruginosa was inhibited by the oversecretion of PQS.AHL-or PQS-deficient V.aeruginosa mutants had a higher ability for nitrogen removal.QS inhibited heterotrophic nitrification mainly via controlling the activity of nitrite oxidoreductase (NXR) and the depressed aerobic denitrification by regulating the catalytic abilities of nitric oxide reductase (NOR),nitrite reductase (NIR),and nitrate reductase (NAR).The addition of citrate as the sole carbon source increased the nitrogen removal efficiency compared with other carbon sources.Nitrite,as the sole nitrogen source,could be used entirely with only the moderate concentration of PQS contained.AHL and PQS controlled both nitrification and denitrification,suggesting that QS plays an important role in nitrogen cycle under aerobic conditions.
查看更多>>摘要：The ever-increasing prevalence of microplastics and different bisphenols made the presence of bisphenol-attached microplastics a critical concern.In this study,experiments were performed to examine desorption behaviors and cytotoxicity performance of contaminated microplastics in aquatic surroundings and intestinal environment after ingestion by organisms (cold-/warm-blooded).The kinetic study shows that the rate of desorption for bisphenols can be enhanced threefold under simulated warm intestinal conditions.The Freundlich isotherms indicate multiple-layer desorption of the bisphenols on the heterogeneous surfaces of polyvinyl chloride (PVC) microplastics.Hysteresis was detected in the adsorption/desorption of bisphenols in a water environment,but no adsorption/desorption hysteresis was observed in the simulated intestinal conditions of warm-blooded organisms.Due to enhanced bioaccessibility,the desorption results imply that the environmental risk of contaminated PVC microplastics may be significantly increased after ingestion at a high bisphenols dosage.Although with different ICs0,the five bisphenols released under the intestinal conditions of warm-blooded organisms can cause higher proliferation reduction in fish and human cell lines than the bisphenols released in water.This study helps elucidate the consequential fate and potential cytotoxicity of contaminated microplastics and the possible implications of the microplastics as a critical vector for bisphenols to increase the potential health risks.
查看更多>>摘要：In order to effectively improve the degradation rate of diesel,a systematic analysis of the degradation mechanism used by immobilized bacteria is necessary.In the present study,diesel degradation mechanisms were assessed by analyzing permeability,biodegradation,adsorption kinetics,and molecular simulation.We found that bacteria immobilized on cinnamon shells and peanut shells degraded relatively high amounts of diesel (69.94％ and 64.41％,respectively).The primary degradation pathways used by immobilized bacteria included surface adsorption,internal uptake,and biodegradation.Surface adsorption was dominant in the early stage of degradation,whereas biodegradation was dominant in later stages.The diesel adsorption rate of the immobilized bacteria was in agreement with the pseudo second-order kinetic model.The immobilized bacteria and diesel interacted through hydrogen bonds.
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