Net primary productivity (NPP) of terrestrial ecosystems is an important metric of ecosystem functioning; however, the understanding of response mechanism of NPP to influencing factors and driving mechanisms are still limited. In this study, taking Anhui province as an example, spatio-temporal changes of NPP and its response to influencing factors were investigated for evaluating the effects of climate change and land use and land cover change (LUCC) on regional NPP. The Carnegie–Ames–Stanford Approach (CASA) model was employed for NPP simulation by using the MODIS normalized difference vegetation index (NDVI) data and meteorological data over 2001–2016. Combined domestic LUCC, the spatiotemporal distribution pattern and dynamic change characteristics of NPP under a long time series and its response to climate factors and human activities were analyzed in the Anhui province. The results indicated that from 2001 to 2016, total NPP had a fluctuated and decreased trend with the variation range between 30.52 and 38.07 TgC in Anhui province. The multi-year average of total NPP was about 34.62 TgC. The highest value was in 2008 and the lowest value was in 2011. Among them, amount of forestland NPP was the most. The spatial distribution of NPP shows that the high value area was mainly distributed in southern Anhui mountain areas and western Anhui Dabie mountain areas; the lower value was distributed in the middle in the study area. The area of which the NPP showed a slight decrease and essentially unchanged accounted for 59.35% and 31.82%, respectively. In general, the correlation between vegetation NPP and temperature was greater than that between precipitation. The vegetations NPP of eight land use types were all positively correlated with temperature. However, the other seven types of land use were negatively correlated with precipitation except cultivated land. In the past 16 years, the decrease of cultivated land areas and the increase of urban and construction land areas contributed a lot to the decrease of vegetation NPP in Anhui province. The NPP changes of different land use types were closely related to climatic factors, land cover area, and vegetation types.

Based on the 1.5 °C temperature control target of the Paris Agreement, the two scenarios in this paper which are 1.5 degree scenario (1.5DS) and 2 degree scenario (2DS) aim to analyze the CO₂ emission space and power transition path constrains of the power sector in China. This paper then discusses the possible scenarios of 1.5DS and 2DS power planning schemes in 2050. The conclusions are as follows: (1) China’s electricity consumption saturation period will occur during the period of 2030–2040; (2) Driven by technology learning, the levelized cost of electricity (LCOE) of wind power will have obvious competitive advantages in 2020 and so does solar power in 2030. However, due to the impact of additional grid connection costs of new energy power, economic advantages can only be obtained in the power market after at least 10 years; (3) The installed capacity of coal power in 1.5DS and 2DS will peak in 2020, and CO₂ emissions will also peak in 2020, then it shows a trend of decreasing year by year. However, it should be noted that 1.5DS is with possibilities, but with enormous challenges as the same time; (4) Accelerating the green and low carbon transition of power sector must be gradually improving the power market and electricity price mechanism, providing a good transition environment for the power sector, developing emerging power technology, and promoting multi-energy complementary systems.

In the third paragraph of Introduction, the sentence “Few scholars have conducted static studies on dual-wavelength UV photocatalytic technologies (Ma 2018)”.

Steroid estrogens are natural hormonal compounds produced by various animals and humans. Estrone (E1), estradiol (E2), and estriol (E3) are the most commonly known estrogens that are released into the environment along with human and animal excreta, which end up polluting water bodies. While these estrogens are usually biotransformed into their respective by-products by various microbial strains, E2 could also be transformed into E1 by 17β-hydroxysteroid dehydrogenases (17β-HSDs) under reducing environmental conditions. However, due to limited further biotransformation of E1, it accumulates to higher levels in water bodies compared to other natural estrogens in the aquatic environment. Given that E1 is one of the potential endocrine-disrupting compounds (EDCs), with several adverse effects on aquatic animals and consequently on the seafood industry, it is vital to remove E1 from the environment via improved steroid bioremediation. In the present study, we successfully isolated a potential E1-degrading microbial strain (named as BH2-1) from soil sediments collected from the Bai Hai mangrove region of the South China Sea. The strain BH2-1 has excellent E1-degrading potential and could degrade 89.5% of E1 after 6 days of incubation in a MSM-E1 medium containing 1% NaCl at pH 6. Besides, after 3 h and 6 h of extraction, two non-accumulating intermediate compounds [3-hydroxyandrosta-5,7,9(11)-trien-17-one and androsta-1,4,6-triene-3,17-dione (ATD)], respectively, were successfully identified using GC-MS analysis. These non-accumulating intermediate compounds have not previously been reported during E1 biodegradation and might be new intermediate metabolites. The identification of these new compounds also gives more insight into the mechanism of E1 metabolism and helps to establish a clear E1 biodegradation pathway, which further enriches our knowledge on the overall microbial steroid degradation pathway. Furthermore, whole-genome sequence analysis of strain BH2-1 revealed the presence of 46 genes that belong to 6 major steroid-degrading gene classes.

Adjoining areas of urban environment has undergone rapid alteration in structure, composition and ecological changes, which makes them a dynamic entity. During the present investigation, herbaceous vegetation were studied in east, west, north and south directions of Ambikapur township at various seasons during March 2017 to April 2018. A total of 18 species representing 11 families were recorded at various directions of Ambikapur township in different seasons. Asteraceae was the predominant family in the study area. Highest species counts were recorded during summer season. Among the herbaceous vegetation, more than two-thirds of the herb species were exotic in nature, revealing the anthropogenic role towards loss of indigenous species. Highest species density was recorded in north direction (152,000 herb/ha during rainy, 104,000 herb/ha in winter and 184,000 herb/ha in summer) and lowest in south direction (90,000 herb/ha during rainy, 72,000 herb/ha in winter and 88,000 herb/ha in summer) in all seasons. Higher Shannon diversity (2.71 in rainy, 2.69 in winter and 3.07 in summer) and richness (0.67 in rainy, 0.52 in winter and 0.66 in summer after west direction) were recorded in the north direction. Total biomass, C storage and CO₂ mitigation were found to be highest towards north direction in all seasons. Argemone mexicana, Cassia tora, Ocimum tenuiflorum and Sida acuata are the most suitable species in terms of C storage, CO₂ mitigation under urban setup. Beside, some weed species also reflected significant potential. CO₂ mitigation by herb species can act as complimentary system towards climate cane adaptation beside other vegetal layers. Such studies are also very much effective towards development of greenery in an urban setup leading to climate mitigation process.

Polluted sterilization condensate discharged from palm oil mill may contain polyphenols that are rich in the antioxidant property. Emulsion liquid membrane (ELM) process is a promising method for polyphenol recovery due to its several attractive features such as high selectivity, simple operation, and low energy consumption. In this study, the condensate was characterized to determine its total phenolic content (TPC), ionic elements, and pH. ELM formulation containing tributylphosphate (TBP) as a carrier, kerosene as a diluent, sorbitan monooleate (Span 80) as a surfactant, and sodium hydroxide (NaOH) as a stripping agent was developed. The results show that sterilization condensate contains 700–1500 mg GAE/L of TPC. During the ELM process, more than 91% of extraction with 83% recovery and 8.3 enrichment were achieved at the favorable condition of 0.1 M TBP, external phase pH 5, 1 M NaOH, 1:5 treat ratio, 5% v/v of octanol as a modifier, and 100 mg GAE/L external phase concentrations. Thus, ELM offers a potential alternative technology to extract and recover polyphenols from palm oil mill sterilization condensate while contributing to sustainable production. Graphical abstract Extraction of polyphenols from palm oil mill sterilization condensate using ELM process

Domestic trade plays a key role in China’s rapid economic progress. However, the increased domestic trade causes significant variations in carbon emission transfer among provinces. This study adopted the multi-region input-output (MRIO) model and social network analysis (SNA) to estimate the carbon emission transfer. Furthermore, the carbon emission transfer network characteristics among 30 provinces and 27 sectors were analyzed by using interprovincial input-output tables for 2007, 2010, and 2012. The results showed that (1) Large differences exist in carbon emission transfer flow and its network characteristics between provinces. (2) The three industrial sectors of metal smelting and pressing sector, power, heat production, and supply sector, petroleum processing, coking, and nuclear fuel processing sector have high carbon emission transfer and pose a strong influence on the carbon emission transfer network. (3) Provinces of the eastern region have a “bidirectional spillover” role, while those of the western region have a mediating role as an “agent.” Provinces of the central region have a “main inflow” role. Finally, useful policy implications and suggestions of this study are summarized.

There is an increasing concern that aquaculture has been implicated in the formation of antibiotic resistance gene (ARG) reservoirs; however, little is known about the consequences of their presence in groundwater. In this study, 22 antibiotics, including four acetylated metabolites, and 27 ARGs were analyzed in fish pond water, surface water, and groundwater of the Honghu Lake in China. Correlations between conventional parameters, ionic composition, antibiotic concentration, and relative abundance of ARGs in water samples were analyzed. Among the three different sources of water, total antibiotic levels were the highest in fish pond water and the lowest in groundwater, with moderate levels in lake water. In surface water, sulfonamides and their metabolites accounted for the highest antibiotic content, whereas tetracyclines were the most frequently found in groundwater samples. Despite the near-undetectable levels of antibiotics in groundwater, the relative abundance of ARGs in groundwater samples was even higher than that in surface waters. The magnitude and extent of ARG migration are likely to be dependent on local antibiotic contamination levels as well as on the local environmental and hydrogeological conditions, with the class 1 integrons (intI1) being essential for the dissemination of such ARGs. The effects of environmental parameters such as antibiotics, dissolved oxygen, HCO₃⁻, and pH on ARGs were highly significant, reflecting the potential impact of these factors on the abundance of ARGs. Our findings thus highlight the need for improved control of the spread of ARGs in and from aquaculture environments.

Financial development is identified as one of the significant factors that affect energy consumption and has been widely discussed in the literature. However, the association between financial development and renewable energy consumption is still at its earlier stage and is limitedly explored. Therefore, the purpose of this study is to examine the non-linear association between financial development and renewable energy consumption in the top renewable energy consumption countries. The study utilized the newly introduced econometric technique panel smooth transition regression (PSTR) model with two regimes on annual panel data consisted of years 1997–2017. The result confirmed that all the financial development indicators increase renewable energy consumption but affect renewable energy consumption differently. Moreover, the economic growth and industrial structure showed a positive and significant association in both regimes, whereas the population showed a negative relationship with renewable energy consumption in a low growth regime but the association becomes positive in high growth regimes. The study suggested several policies for the top renewable consumption countries.

Phytoremediation assisted by plant growth-promoting bacteria (PGPB) is considered an effective strategy for cadmium (Cd) removal in contaminated sites. This study uses a hydroponic experiment to investigate how Sphingobium yanoikuyae Sy310 affects Cd accumulation capacity and tolerance of Salix matsudana Koidz (S. matsudana) roots. The results showed that Cd induced growth change and physiological response on S. matsudana roots, displaying with reduced root length, increased antioxidant enzyme activities, and most importantly, enhanced cell wall polysaccharide contents. The Sy310 inoculation enhanced Cd accumulation in roots and alleviated the Cd toxic effects by regulating root growth, antioxidant enzyme system, and cell wall polysaccharide remodeling. Under Cd stress, Sy310 significantly induced increased root length and biomass, as well as higher root IAA level and Cd retention in cell walls. The Sy310 inoculation enhanced root pectin and hemicellulose 1 content, and pectin methylesterase activity, indicating that more amount of -COOH and -OH in cell walls for binding Cd. With Sy310-regulated extensive Cd regional sequestration in root cell walls and enhanced catalase activity, the root H₂O₂ and malondialdehyde content decreased, which contributes to improve Cd tolerance of S. matsudana roots. Furthermore, the Sy310 inoculation did not affect root cell wall structure and oxidative stress in the absence of Cd, representing a well-symbiotic relationship between Sy310 and S. matsudana. Therefore, Sy310 plays an important role in expediting the phytoremediation process of Cd with S. matsudana and has practical application potential.