RESUMO
The use of biochar to improve adversity of soil has received increasing attention. Enteromorpha prolifera biochar is used to repair coastal saline-alkali soil, which can not only utilize Enteromorpha prolifera but can also increase the scale of the coastal land reserve. In this study, the method of soil culture experiments was used to explore the effect and pathway of 0%-3% addition of Enteromorpha prolifera on the improvement of saline-alkali soil. The results showed that the optimum preparation temperature of Enteromorpha prolifera biochar suitable for saline-alkali soil improvement was 400â, and the optimum addition amount was 1.5%. At the optimum level, although the biochar had a negative effect, such as increasing soil salinity (0.12%) and pH (1.49%), it also produced positive effects, such as reducing soil Na+/K+ by 55.73%, increasing mineral content, and improving water conductivity. Enteromorpha prolifera biochar improved soil physicochemical and biological properties, increased nutrient content, enhanced microbial activity, improved soil nutrient availability, and produced positive effects. These positive effects were characterized by reducing soil bulk density by 11.35%, increasing organic matter by 42.64%, increasing the proportion of organic carbon in total carbon by 3.84 times, increasing the proportion of available phosphorus in total phosphorus by 4.15 times, and increasing soil invertase activity by 2.39 times, urease activity by 1.18 times, and catalase activity 1.50 times. Therefore, the positive effect of Enteromorpha prolifera biochar on saline-alkali soil is more than negative, and it can be used for the improvement of coastal saline-alkali soil. This study provides a new path for the resource utilization of Enteromorpha prolifera and the improvement of the ecological environment of coastal saline-alkali soil.
Assuntos
Carvão Vegetal , Solo , Álcalis , CarbonoRESUMO
At present, research findings on pharmaceuticals and personal care products (PPCPs) in coastal areas are still unclear, and there is a need to develop a method to detect more PPCPs simultaneously in seawater. In this study, nine compounds of non-steroidal anti-inflammatory drugs, antibiotics, lipid regulators. and stimulants were selected as analytes. Solid phase extraction (SPE) was used to extract the compounds, which were then analyzed by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). The optimum experimental conditions, such as the filler, eluent, pH, flow rate, and the reduction of matrix effect were optimized during the SPE. The results showed that the best extraction column was CNW HLB, the best eluent was methanol:acetonitrile (1:1, volume ratio), the best eluent volume was 6 mL, the best pH was 7, the best flow rate was 5 mL·min-1, the amount of EDTA-Na2 added was 1 g, and the best concentration multiple was 500. The linear regression equations of all PPCPs had good linearity. Correlation coefficients were>0.999, recovery rates were between 82%-106%, relative standard deviations were between 1.6%-14%, and detection limits were between 0.01-2 ng·L-1, thus satisfying the requirement of trace analysis in seawater. Distribution characteristics and sources of PPCPs were studied in the Yellow Sea and the East China Sea during summer 2018. All nine PPCPs were detected and the main pollutants were NAP, IBU, GEM, CAF, and ASA. High concentrations of PPCPs were generally detected in the nearshore area and displayed conspicuous decreasing tendencies from the inshore towards the offshore. The concentrations of PPCPs in the Yellow Sea were higher than of those in the East China Sea, and this was related to there being more sources of pollutions and poor water exchange capacity in the Yellow Sea. Principal component analysis showed that the main source of PPCPs was terrestrial input. The environmental risk assessment of PPCPs indicated that risk quotients (RQs) of IBU and NAP (0.1-1) posed a medium risk to the aquatic environment, while others posed low risk to organisms.