Colloidal phosphorus (CP) as an additional route of P mobilization in soil solution has gained much attention. A batch experiment was conducted to investigate the effect of sheep manure-derived biochar (SMB) on CP release from various land uses (paddy, vegetable, tea, and citrus) at a rate of 0% as a control treatment (CK), 1% as a low (L) level, 2% as a middle (M) level, and 4% as a high (H) level of SMB application. The CP and MRPcₒₗₗ in the solution increased from 30.58 to 88.97% and from 2.45 to 55.54% of total P (TP), respectively. The SMB enhanced CP release in all the soils and all the treatments (except CK and L levels in tea soil; CK, L, and M levels in vegetable soil; and L and M levels in citrus soil). Multiple linear regression revealed a significant correlation between CP and MRPcₒₗₗ and between colloidal iron, aluminum, calcium, and total organic carbon (Fecₒₗₗ, Alcₒₗₗ, Cacₒₗₗ, and TOCcₒₗₗ) and pH, which may play an important role as CP carriers that could depend on the pH. This study suggests that the application of SMB in the soil at an appropriate rate of 1 and 2% for tea and vegetable soils, respectively, could be beneficial to avoid the risk of CP release in water bodies.

Effective concentrations of potassium thiocyanate (KSCN) to rice seedlings were experimentally determined using relative growth rate as a sensitive endpoint. Agilent 44-K rice microarray was used to profile the molecular responses of rice seedlings exposed to thiocyanate ion (SCN⁻) at three different effective concentrations (EC₁₀, EC₂₀, and EC₅₀). A total of 18,498 known genes were collected from SCN-treated rice microarray analysis. Out of all, 1603, 1882, and 5085 differentially expressed genes (DEGs) were observed at EC₁₀, EC₂₀, and EC₅₀ concentrations, respectively. More upregulated/downregulated DEGs were detected in shoots than in roots after SCN⁻ exposure. Gene functions and pathway enrichment analysis of DEGs indicated that different effective concentrations of SCN⁻ resulted in multiple enriched GO categories and KEGG pathways and outcomes were quite tissue-specific. Different regulations and adaptations of gene expression in molecular function (MF), biological process (BP), and cellular components (CC) were observed in rice tissues at different effective concentrations of SCN⁻, suggesting their different responsive and adaptive strategies. Information collected here presents a detailed description of SCN-induced alternations of gene expression in rice seedlings and provide valuable information for further searching specific genes participating in transportation, phytotoxic responses, and detoxification of SCN⁻ in rice seedlings.

Treatment of wastewater by using of microalgae is a cost-effective system. Chlorella sorokiniana pa.91 and Chlorella vulgaris were studied in this research. Chlorella sorokiniana pa.91 was isolated from the dairy wastewater. In this study, treated wastewaters in preliminary and secondary treatment units of dairy wastewater treatment plant were used as medium. Maximum growth of two species of microalgae was examined in these two mediums, and also, nutrient removal was studied. The performance of two species of microalgae was studied on laboratory scale at different temperatures and light intensities. The best observed temperatures for Chlorella vulgaris and Chlorella sorokiniana pa.91 were 25 and 28 °C, respectively, and the best observed performance for them was obtained at 7500 lx. The values of specific growth rate and biomass productivity in effluent of preliminary treatment unit for Chlorella vulgaris were 0.331 day⁻¹ and 0.214 g L⁻ˡ day⁻¹, respectively, and for Chlorella sorokiniana pa.91 were 0.375 day⁻¹ and 0.233 g L⁻ˡ day⁻¹, respectively. Also, these parameters for Chlorella vulgaris in effluent of secondary treatment unit were determined 0.359 day⁻¹ and 0.166 g L⁻ˡ day⁻¹, respectively, and for Chlorella sorokiniana pa.91 were obtained 0.422 day⁻¹ and 0.185 g L⁻ˡ day⁻¹, respectively. The removal efficiency of nitrate, ammonia, phosphate, and chemical oxygen demand for Chlorella sorokiniana pa.91 and Chlorella vulgaris in both of effluents was more than 80%. Based on the results, effluent of treatment plants can be a suitable microalgae growth medium, and the microalgae can be used as effective post treatment system.

In wetland ecosystems, vegetation can float freely on water surface, forming dense canopy which may play important ecological roles. This is especially true in many urban wetlands in which fluidity is low and nutrient level is high. So far, effects of free-floating vegetation on abiotic and biotic factors of wetlands have been known, while little on wetland ecosystem functions such as litter decomposition. To examine whether the canopy of free-floating vegetation on water surface will influence litter decomposition in wetlands or not, we conducted a 50-day in situ decomposition experiment in a subtropical urban pond wetland, in which litter bags of nine combinations of three mesh sizes and three litter species were put on the bottoms of total 22 ponds which were half with and half without free-floating vegetation canopy on the water surface. The ponds with and without the canopy had different water physicochemical properties. Overall, the canopy, the species identity, and the mesh size significantly decelerated mass loss and carbon loss of leaf litters while slightly on nitrogen loss. Effects of the canopy on leaf litter decomposition also showed species- and mesh size-dependent. Our results suggest that free-floating vegetation on water surface can alter water environmental factors and consequently change ecosystem functioning in wetlands.

This study aimed to investigate the protective effects of Eugenol (EUG), an effective antioxidant phenolic compound with a radical scavenging activity against citrinin (CTN)-induced toxicity in vitro using HCT116 cells. CTN is a well-known mycotoxin found in different constituents of the food chain. This environmental contaminant produces free radicals which interacts with cellular macromolecules and produces oxidation of protein, lipid, and DNA. The cytotoxic effects were monitored by measuring cell viability, reactive oxygen species (ROS) generation, antioxidant enzyme activities, malondialdehyde (MDA) production, protein oxidation, and DNA fragmentation. Our results have shown that the pretreatment of HCT116 cells with EUG, 2 h prior to citrinin (CTN) exposure, significantly decreased CTN-induced cell death, inhibited ROS generation, modulated activities of both catalase (CAT) and superoxide dismutase (SOD), and reduced MDA production. Level of protein-bound sulfhydryls and DNA fragmentation were also declined as compared with CTN-treated cells. These findings suggest that EUG would be an effective protective agent against CTN-induced oxidative stress, and thereby, it may complement and add to the functions of antioxidant vitamins and enzymes as a protection against the cytotoxicity of this mycotoxin.

The present research highlights the use of a montmorillonite clay to remove p-nitrophenol (PNP) from aqueous solution. The montmorillonite clay was characterized using powder X-ray diffraction, Fourier-transformed infrared spectroscopy, scanning electron microscopy, X-ray fluorescence, Brunauer-Emmett-Teller analyses, and zero point charge in order to establish the adsorption behavior-properties relationship. The physiochemical parameters like pH, initial PNP concentration, and adsorbent dose as well as their binary interaction effects on the PNP adsorption yield were statistically optimized using response surface methodology. As a result, 99.5% removal of PNP was obtained under the optimal conditions of pH 2, adsorbent dose of 2 g/l, and PNP concentration of 20 mg/l. The interaction between adsorbent dose and initial concentration was the most influencing interaction on the PNP removal efficiency. The mass transfer of PNP at the solution/adsorbent interface was described using pseudo-first-order and intraparticle diffusion. Langmuir isotherm well fitted the experimental equilibrium data with a satisfactory maximum adsorption capacity of 122.09 mg/g. The PNP adsorption process was thermodynamically spontaneous and endothermic. The regeneration study showed that the montmorillonite clay exhibited an excellent recycling capability. Overall, the montmorillonite clay is very attractive as an efficient, low-cost, eco-friendly, and recyclable adsorbent for the remediation of hazardous phenolic compounds in industrial effluents.

In order to improve the heavy metal wastewater treatment by avoiding formation of amorphous sludge phase, we develop a faster formation of high crystalline layered double hydroxide (LDH) sludge to remove Cu and Zn from wastewater by controlled double-jet precipitation (CDJP) without hydrothermal or heat aging post-treatment. A series of experimental procedures are conducted to determine the optimal parameters. Results show that the optimal adding rate, pH value, and stirring rate is 0.5 mL min⁻¹, 9.0, and 500 rpm, respectively. The CuZnAl-LDH phase sludge is formed in a well-crystallized hexagonal platelet, which assembled into a flower-like architecture. Comparative studies show that the formation of amorphous LDH sludge in conventional precipitation (CP) could be divided roughly into two stages—from the mixed copper hydroxide, zinc hydroxide, and scarbroite to the mixed low crystallinity CuAl-LDH and ZnAl-LDH. However, in CDJP method, the high crystalline LDH sludge evolved from a new four-step evolution process that is the formation of an amorphous (quasi-)multinary metastable ternary CuZnAl-LDH phase, followed by the indiffusion of cations and substitution of anions to fabricate crystalline LDH, the integrated LDH hexagonal platelets assembled into a flower-like architecture by the screw dislocation growth mechanism, the coarsening growth of each ternary LDH platelet, respectively. Thereinto, the formation of (quasi-)multinary metastable LDH phase instead of metal hydroxide in initial stage would be an obvious advantage of the CDJP method compared to CP method due to the former skipping the sequential precipitation.

This paper first visits the clean energy consumption for 21 OECD countries and 14 Emerging market countries through a panel unit root test with both sharp and smooth breaks covering the period from 1965 to 2016. The time-varying fitted intercepts of the estimation could better fit the path of clean energy consumption for selected countries. The empirical results suggest that not only sharp breaks should be considered, but also smooth breaks. The economic implications are insightful for the convergence of clean energy consumption for 22 of 35 countries. For USA, Canada, Austria, Germany, Greece, Ireland, UK, Australia, New Zealand, South Korea, Hungary, China, Philippines, and Thailand, the clean energy consumption is divergence. Policy encouragement policy would permanently affect not only clean energy consumption path, but also aggregate economic sectors related to consume clean energy.

In this paper, we discussed some major issues that hinder giant panda protection, such as diverse and mixed threats, habitat fragmentation, as well as the survey method to be improved, and some new protection actions appeared, such as the pilot program for the giant panda national park system and the administration of the giant panda national park was established. These information could provide important information for giant panda protection.

The ecosystem of the Seocheon coastal wetland (SCW), one of the wetland protected areas in South Korea, was registered in the Ramsar Wetlands in 2009 as an area rich in biodiversity and inhabited by endangered wild animals and plants. Since then, preserving the ecosystem of the SCW has emerged as an important task. Thus, the South Korean government is carrying out various research and management projects to preserve the ecological integrity of the SCW. This article aims to analyze public willingness to pay for preserving the SCW. For this purpose, 1000 households were surveyed, applying the contingent valuation (CV) method during September 2017. The respondents clearly understood the CV question and gave meaningful answers. The results show that an average value for the preservation was statistically significantly estimated to be KRW 2341 (USD 2.04) for all respondents. The national value expanded from the sample to the population is worth KRW 47.79 billion (USD 42.15 million) per year. Therefore, it can be seen that the public have sufficient acceptance for preserving the SCW.