Vegetation plays an important role in the energy exchange, water cycle, carbon cycle, biogeochemical cycle, and maintenance of surface ecosystems. In recent years, regional vegetation cover has changed significantly. This study used statistical analyses, including the Mann-Kendall trend test, the Hurst exponent, and Pettitt test, to analyze the characteristics of temporal and spatial variation of vegetation coverage in the Xijiang River basin from 2000 to 2013. The results showed that vegetation coverage of 98.76% of the Xijiang River basin is weakly variable (Cv < 0.1). The area with significantly increased vegetation accounts for 43.45% of the total area (p < = 0.05). A total of 19.47% of vegetation coverage in the Xijiang River basin had significant change-points from 2004 to 2008 (p < = 0.05), and the area of concave change-points accounted for 25.99% of the total area of point increased the vegetation coverage. At an altitude of 500–2000 m, the altitude has an inhibitory effect on vegetation coverage. When the slope is less than 35 degrees, the slope has a promoting effect on vegetation coverage. Rich precipitation resources are the main source of soil water supply, and higher temperature provides better thermal energy resources, which may have a significant impact on vegetation growth in the future and cause time lag effects of climatic factors on vegetation coverage. The vegetation coverage and the area affected by the precipitation and temperature (time lag factors) accounted for 32.99% and 31.47% of the total watershed, respectively. The correlation between climatic factors, topographic factors, and vegetation coverage increased over time. The results from this study will help to further deepen the understanding of vegetation cover and its influencing factors, and provide a scientific basis for ecological restoration projects such as vegetation restoration in the Xijiang River basin of China.

Most previous studies of phosphorus (P) removal focused on investigation of the soluble, and particulate P, but ignoring the difference between organic and inorganic P. In this study, the effects of various flocculants, namely polyacrylamide (PAM) and polyaluminum chloride (PAC), on flocculation efficiency in different P speciations (organic and inorganic P) were investigated. A modified method to differentiate between organic and inorganic P content in secondary effluent samples was developed. The results showed that P speciation based on organic/inorganic P (Pearson’s correlation R = 0.915, p < 0.05) was more effective than those based on soluble/particulate P (p > 0.05) in evaluating the P content in secondary effluents. The liquid ³¹P nuclear magnetic resonance measurements results indicated that PAM was more effective in removing organic P (phosphonates and orthophosphate monoesters) rather than inorganic P. However, PAC was more effective in removing inorganic P (particularly orthophosphate) rather than organic P. Based on the modeled results of a response surface methodology (RSM), doses of PAM and PAC were optimized for secondary effluent containing different amounts of organic and inorganic P from the two typical wastewater treatment plants (WWTPs) in Wuhan city, China.

In order to learn about the status of heavy metals and ecological risks in the water of thirteen China’s costal shellfish culture areas, principal component analysis was applied to analyze the distributions of five kinds of heavy metal, while the safety threshold method was employed to evaluate the ecological risks. The results showed that among the 13 shellfish culture areas, the average metal concentrations were in the order of Zn > Cu > Pb > Hg > Cd, and all heavy metals were below the second standards for sea water quality of China. The distribution of heavy metals in 13 shellfish culture areas was reflected by two principal components with the contribution rates of F1(Cu) and F2(Zn, Pb) were 36.14% and 23.40%,respectively,which was less affected by economic and geographical differences. The ecological risks assessment of five kinds of heavy metals showed that MOS10 was more than one; the probabilities of five heavy metals affecting more than 10% of aquatic organisms were 49.52%, 24.11%, 17.49%, 22.05%, and 5.66%, respectively, the ecological risk of five main heavy metals was in order Cu > Zn > Cd > Pb > Hg. In the selected thirteen shellfish culture areas, the value of msPAF of seven culture areas was higher than 20%, indicating these areas are highly ecologically contaminated by heavy metals, and the other four shellfish culture areas with value of 0, indicating that these areas have no ecological risk of heavy metals pollution.

The continuous decline in the resource and environment-carrying capacity of cultivated land resources has seriously threatened the sustainable supply of cultivated land resources in China. Using the Hicks-Moorsteen total factor productivity index method, we examine the total factor productivity of cultivated land use (CL-TFP) in China from 2003 to 2017 under environmental constraints. We further use a panel Tobit model to estimate the effect of its influencing factors. The results show that the CL-TFP presents a fluctuating upward trend and reaches data envelopment analysis (DEA) efficiency during the sample period. The regional results reveal a significant spatial difference, especially in the mid-west region, which fails to reach DEA efficiency. China’s main cultivated land did not realize economies of scale. The phenomenon of spatial polarization in what we refer to as very low-value areas and very high-value areas is clear, and the changes are gradual. Regarding the determinative influencing factors, results from the panel Tobit model show that cultivated land usage tax and environmental pollution control investment have no significant effect on CL-TFP, while income level and agricultural intermediate consumption do have a positive effect on CL-TFP. The empirical evidence can help policymakers craft and frame effective policies that improve the utilization efficiency of China’s cultivated land resources.

Polyethyleneimine modified activated carbon (PEI-AC) was prepared through a treatment of immersion, and used for the adsorption of formaldehyde. The adsorption capacity of formaldehyde by unmodified AC is 190.1 mg g⁻¹, and the adsorption capacity of formaldehyde can reach to 317.6 mg g⁻¹ after 10 g L⁻¹ of PEI modified, being about 1.67 times than unmodified activated carbon (AC: 191.2 mg g⁻¹). And the 10 g L⁻¹ of PEI modified AC (PAC-30) has the highest adsorption capacity of formaldehyde, reached to 650 mg g⁻¹, with an increasing magnitude of 240% in comparison with that without modified AC. This is mainly due to changes in the pore structure and surface functional groups after modification. However, as the PEI concentration increases, the adsorption performance is inhibited. Through kinetic studies, it was found that all adsorption curves follow the second-order kinetics, and the breakthrough curves follow the Boltzmann model, and the adsorption process can also be described by the intraparticle diffusion model.

Planktonic ciliate composition and distribution together with physicochemical variables were investigated in a shallow hypersaline lagoon, Pulicat, India, during three seasons, i.e., pre-monsoon (PRM), monsoon (MON), and post-monsoon (POM). The low freshwater inflow, evaporation, and closure of the lake mouth were the main factors for the hypersaline conditions in Pulicat Lake. The average depth and salinity were 1.8 ± 0.12 m (0.8 to 2.8 m) and 35.3 ± 1.68 (12.5 to 61), respectively. A total of 29 ciliate taxa belonging to 18 genera and five classes were identified. Strombidium conicum (24%) was the dominant species followed by Euplotes sp. (10.7%) and Stenosomella sp. (7.02%). Spirotrichea (84%) was the dominant class followed by Oligohymenophorea (9.6%) and Heterotrichea (5.8%). Fabrea salina, a typical species in hypersaline systems, was abundant at locations where the salinity was more than 35. Multivariate analysis using the Bray–Curtis similarity, followed by SIMPROF (Similarity Percentage Analysis), on ciliate abundance data revealed three ciliate assemblages characterizing south, central, and north of the lake at 40% similarity (SIMPROF, cophenetic correlation = 0.622, P = 5%). Both ciliate abundance and chlorophyll-a were positively correlated with salinity. Species richness and evenness were higher in the south sector when compared with those in the other two sectors. Biotic-environmental interaction through canonical correspondence analysis (CCA) inferred that the combined effects of salinity, chlorophyll-a, and nutrient levels are the key factors responsible for the distribution of the ciliate species, suggesting that ciliates can be considered to be potential bioindicators of water quality.

The presence of endocrine disrupting compounds in water receptor bodies, such as drugs, currently has in scientific field a great focus of studies focused on advanced water treatment techniques that enable the decontamination of water sources and public supply. In this context, this study focused on the characterization and evaluation of photocatalytic activity of catalysts calcined and uncalcined synthesized TiO₂ and the commercial sol-gel route from caffeine degradation. The photocatalysts were characterized by N₂ physisorption, X-ray diffraction, scanning electron microscopy (SEM/EDS), photoacoustic spectroscopy, and infrared spectroscopy (FTIR). They seek to evaluate the main textural, structural, chemical, and morphological differences that the method of synthesis can promote in obtaining a titanium oxide-based catalyst. Thus, the results of this study demonstrate that the synthesis method significantly influences the activity of the materials and that calcined TiO₂ catalyst prepared using the sol-gel method has promising photocatalytic capabilities for the elimination of drugs such as caffeine when present in wastewater.

Ruminant livestock production processes are the major sources of methane production in agriculture sector triggering global environmental pollution. Above 90% of world buffalo population present in Asian countries, India ranks first and contributes significantly to the environmental pollution by enteric methane emissions. In this study, we examined the effect of dietary composite feed additive supplementation on ruminal methane production, nutrient utilization, milk production and immune status of buffaloes (Bubalus bubalis). Eighteen lactating Murrah (Bubalus bubalis) buffaloes at early stage of lactation were divided into two groups of nine animals and fed a composite feed additive [consisted of (%, w/w) dried and ground leaves of Cordia dichotoma and Holoptelea integrifolia, 31.4 each; garlic oil, 0.6; sodium nitrate, 3.1; magnesium sulphate, 8.4; mustard oil, 12.6 and cottonseed oil, 12.5] which contained an ideal combinations of methane inhibitors, alternate hydrogen sinks and rumen stimulating agents to treatment (CFA) group animals along with basal feed of chaffed green sorghum (Sorghum bicolor) fodder, chaffed wheat straw and concentrate mixture for maintenance and milk production. The results showed a decrease (44.6%) in methane concentration in exhaled air of CFA group buffaloes with increase (p < 0.05) in digestibility of feed in comparison to control (CON). Total digestible nutrient (TDN) content of the ration fed to buffaloes of CFA group was significantly (p < 0.05) increased. The daily milk yield, 6% fat corrected milk (FCM) yield and immune response were also increased (p < 0.05) in CFA group. The study suggests that the supplementation of composite feed additive was effective to reduce enteric methane emissions and improvement in production performance and immune status of buffaloes.

The aim of the present study was to evaluate the efficiency of a new magnetic coagulant, obtained from Moringa oleifera seeds protein functionalized with iron oxide nanoparticles to remove four anionic synthetic dyes with coagulation/flocculation assays followed by magnetic sedimentation. The results showed that the presence of a magnetic field during sedimentation considerably accelerates the separation and increases the dye removal efficiency. Amaranth dye removal increased from 45 to 86% and Sunset Yellow from 15 to 69% with the presence of magnetic field, while Reactive Black 5 and Brilliant Blue reached 94% and 52% removal, respectively. For AM and SY dyes, the best protein concentration is 150 mg L⁻¹, for RB5 dye is 115 mg L⁻¹, and for BB dye is 75 mg L⁻¹. The sedimentation time decreased from 30 to 5 min with magnetic sedimentation. The residual value of AM dye decreased from 10.76 mg L⁻¹ to approximately 2.71 mg L⁻¹, and with SY the residual concentration decreased from approximately 16.79 mg L⁻¹ to 6.36 mg L⁻¹. The removal of BB and RB5 dyes reached an approximate final value of 48.2 mg L⁻¹ (52%) and 1.18 mg L⁻¹ (94%).

The present work designs a low-cost biological treatment strategy consisting of constructed wetlands (CWs) followed by entrapped algae (EA) for removing nutrients (PO₄³⁻, NO₃⁻, and NH₄⁺) and organic matters from high-strength wastewater. The CWs are efficient means for organic pollutant removal but face challenges in nutrient removal. Algae have a high growth rate and nutrient uptake capabilities from wastewater. The severe challenge that limits the use of algae for nutrient removal from wastewater is its post-treatment separation from wastewater. This work presents a strategy to address the described problems of CWs and algae-based system. It also assesses the performance of the system using synthetic wastewater. A combined system of CW followed by EA (CW-EA) was able to treat 86.0% of phosphate, 95.0% of nitrate, 74.0% of ammonium, and 87.0% of chemical oxygen demand (COD) from high-strength wastewater.