Urban vegetation canopies significantly alter the biogeochemistry of atmospheric deposition, yet the molecular-level characteristics of leached dissolved organic matter (DOM) and nutrient dynamics remain poorly understood. We investigated the hydrochemical transformation of precipitation by two distinct plant functional types. Across 17 storm events, paired rainfall and throughfall samples from eight urban plant species (five shrubs, three arbors) were characterized using high-performance size-exclusion chromatography (HP-SEC), three-dimensional excitation–emission matrix fluorescence spectroscopy (3D-EEMs), and nutrient flux quantification. Results revealed markedly divergent nutrient leaching behaviors. Arbor throughfall exhibited a net increase in total nitrogen (TN) flux of 433.99 kg/km2 relative to incident rainfall and a higher nitrogen/phosphorus ratio of 13.73, whereas shrub throughfall showed a 3.5-fold greater net increase in phosphorus flux than arbor throughfall and substantial dissolved organic carbon (DOC) export. Crucially, HP-SEC demonstrated a fundamental restructuring of DOM. Shrub leachates exhibited high aromaticity and their concentration of high-molecular-weight aliphatic biopolymers was nearly double that of arbors, significantly altering the bioavailability and environmental reactivity of canopy-derived carbon. Multivariate analysis revealed strong associations between canopy-derived DOM and inorganic constituents, suggesting that DOM may contribute to their co-transport through potential complexation and carrier effects. Overall, these results provide site-specific evidence that vegetation type can influence the chemical composition and throughfall-mediated transport of DOM and nutrients, with potential implications for nutrient delivery to receiving waters and the management of urban vegetation.

Resuspension is a crucial process for releasing endogenous pollution from shallow lakes into the overlying water. Fine particle sediment, which has a higher contamination risk and longer residence time, is the primary target for controlling endogenous pollution. To this end, a study coupling aqueous biogeochemistry, electrochemistry, and DNA sequencing was conducted to investigate the remediation effect and microbial mechanism of sediment elution in shallow eutrophic water. The results indicated that sediment elution can effectively remove some fine particles in situ. Furthermore, sediment elution can inhibit the release of ammonium nitrogen and total dissolved phosphorous into the overlying water from sediment resuspension in the early stage, resulting in reductions of 41.44 %-50.45 % and 67.81 %-72.41 %, respectively. Additionally, sediment elution greatly decreased the concentration of nitrogen and phosphorus pollutants in pore water. The microbial community structure was also substantially altered, with an increase in the relative abundance of aerobic and facultative aerobic microorganisms. Redundancy analysis, PICRUSt function prediction, and the correlation analysis revealed that loss on ignition was the primary factor responsible for driving changes in microbial community structure and function in sediment. Overall, the findings provide novel insights into treating endogenous pollution in shallow eutrophication water.

沉积物中易悬浮颗粒再起悬与沉积层的组成和结构特征直接相关.合肥、芜湖的5个水体共44个位点的表层沉积物中黏土含量平均不到10％,而粉砂平均含量超过60％;有机质含量介于2.40％和18.84％之间,平均7.05％.采用自制的淘洗装置对各沉积物样品分别进行2～5次(水与初始泥量的重量比为50,每次淘洗3min、沉降2min之后转移淘洗水)的淘洗,观察分析淘洗之后沉积物感官、粒度特征、有机质含量、泥水界面特点及颗粒再悬浮沉降特性.结果 显示,淘洗之后沉积物黑臭感官明显改善,重量平均减少了61.21％,平均有60.32％的有机质被同步转移;黏土组分占比平均减少72.94％,粉砂组分减少59.48％,而砂组分占比增加了137.65％;模拟扰动后上覆水浊度相比未淘洗的样品大幅降低且颗粒沉降明显加快.

针对我国肥料农药高施低效的关键问题,以天然黏土为基础材料,建立了基于纳米网捕的化肥农药迁移阻控方法,研制出控失化肥和控失农药***并实现产业化.迄今,技术累计推广约2亿亩,创造显著的经济、社会和生态效益,为我国肥料农药双减提供有效科技支撑,对于推进农业高质量发展和乡村振兴两大战略具有重要意义.

In development of novel chemical fertiliser loss control techniques for promoting agriculture, nanomaterials and nanotechnology have been involved in applications. In this study a type of natural nanoclay material, attapulgite, was applied after electron beam treatment of the as-mined material as a chemical fertiliser loss control agent (LCA). The LCA was mixed with normal chemical fertiliser to form loss control fertiliser (LCF). The LCF was applied to Thai rice growing in a farm field. In the aqueous phase, LCF self-assembled to form 3D micro/nano networks. The fertiliser could form fibrous crystals with the clay rods as the nucleus, obtaining a higher nitrogen spatial scale, so that the nutrient could be retained by the soil filtering layer, and thus nitrogen loss was reduced. Two types of LCFs, machine-made and manmade, were applied. After the LCF was applied, the growth and crop yield of the rice were studied and compared with that obtained with normal fertiliser, and the pH, N and K in soil were measured and analysed. On the control of releasing nitrogen, the two LCFs played some roles compared with the fertiliser control, particularly for some varieties, and the machine-made LCF performed better. On the control of the soil pH to be not too acidic, the manmade LCF performed better but was variety dependent. On the control of releasing K, a comparison showed that the manmade LCF was better than the machine-made LCF. The differences in the LCF behaviour should be correlated with the LCF structure which was due to how they were made.

Negative air ion concentrations (NAIC) are being used as a significant indicator of air quality in urban life. Generally, the NAIC over unpaved areas, e.g., meadows, fields, in cities is around several hundred ions/cm(3), which is not high enough to promote human health. In this study, to increase the outdoor NAIC over urban lawns, research was carried out on the biogeneration of negative air ions with lawn grasses by adjusting discharge of kV electricity under different conditions. The results showed that lawn grasses with gladiate, lanceolate or angustifoliate leaves stimulated by kV electricity, generated high NAIC predominantly from the leaf tips at the order of 1E6 ions/cm(3). The discharges could be divided into continuous and discontinuous discharge according to the voltage of the kV electricity. Different substrates, including soil, pearl, salt and sand were all suitable for exposure to the different discharges. Moreover, when NAIC was maintained at a high level, the positive air ion concentration decreased with an increase of the planting densities of grass. After discontinuous discharge, normal growth of the lawn grasses, including superoxide dismutase activity and chlorophyll content were not significantly influenced.

To investigate the growth of habitus, ability of nutrient removal, and prospect for large-scale application of planting water spinach (ipomoea aquatic) by floating beds in large acreage water body, the study compares the biomass, total nitrogen (TN) and total phosphorus (TP) content of water spinach, grown in soil and eutrophic water body, and further enlarges the demonstration in Baihe wetland park at Chichou, Anhui. It is found that during the same growing period, the biomass of water spinach grown in eutrophic water could reach on average 1.6 kg per plant with a length of 5 m, in great contrast to the plants grown in soil. The great growing potential of water spinach in eutrophic water is in agreement to its particularly prosperous root system, which takes 35%of the fresh weight of a single plant. TN and TP are separately measured for root, stem and leaf parts, and the ratios of TP/TN in each part for plants grown in eutrophic water are 3.26, 3.65 and 1.51 times of plants grown in soil. High biomass and phosphorus absorption potential are important features for its application in restoration of eutrophic water. Demonstration field study in Baihe wetland park showes a yield of 9.3 t per 667 m2, and TN of the water body is decreased from 3.624 mg·L-1 to 2.181 mg·L-1, TP from 0.187 mg·L-1 to 0.144 mg·L-1. The work provids a successful example of using water vegetables, at large-scale, for restoration of water nitrification. The strategy of producing edible vegetables along with bio-restoration of eutrophic water body and important aspects for future research are discussed.

Harmful algal bloom (HAB) produced by several cyanobacterial species is a significant threat to many aquatic ecosystems around the world. Recently frequent occurrence of serious algal bloom in Lake Taihu, Lake Dianchi and Lake Chaohu has become a serious concern in China. Although various methods are currently being used to control toxic blue-green algal water blooms, many of their techniques are of limited use. In this study, the use of 254 nm UV-C radiation to control algal growth was evaluated using Microcystis aeruginosa as test species. The UV-C irradiation of more than 99 µW cm -2 light intensity was found to be lethal to M. aeruginosa. Under incubated conditions with petri dishes and with 20 hours exposure to the UV-C irradiation of 1370 µW cm -2 , almost all the cells settled to the bottom of the incubation Petri dishes, whereas all the unirradiated cells remained in suspension. It was also observed by microstructure and ultrastructure slice-ups that the UV-C radiation had a significant kill and wound effect on algal cells and controlled algal growth. After a UV-C dose of no less than 7.2 J cm -2 , most algae cells dispersed, whereas all the unirradiated cells remained agglomerative.

We proposed a method to inactivate M. aeruginosa by using discharge plasma taking at the gas-solution interface supplied by DC power. Multiple analysis techniques including fluorescence excitation emission matrix (EEM) and flow cytometry (FCM) were used to reveal the inactivation mechanism of M. aeruginosa. The photosynthetic pigment contents including phycocyanin, chlorophyll and metabolites were examined quantitatively. The DC glow discharge plasma caused an increased level of reactive oxygen species (ROS), and the damage of M. aeruginosa cells are mainly attributed to the oxidative stress including (OH)-O-center dot attack and H2O2 oxidation. Our findings demonstrate that plasma oxidation is a promising technology for inactivation of M. aeruginosa cells with simultaneous removal of microcystins and so it may lead us to a new route to efficient treatment of cyanobacterial blooms. (c) 2014 Elsevier B.V. All rights reserved.

Energetic particles exist ubiquitously in nature, and when they hit DNA molecules in organisms, they may induce critical biological effects such as mutation. It is however still a challenge to measure directly and quantitatively the damage imposed by the energetic ions on target DNA molecules. In this work we attempted to employ Fourier transformation infrared (FTIR) spectroscopy to assess the ion-induced direct damage of four nucleic acid bases, namely, thymine (T), cytosine (C), guanine (G), and adenine (A), which are the building blocks of DNA molecules. The samples were prepared as thin films, irradiated by argon ion-beams at raised ion fluences, and in the meantime measured by FTIR spectroscopy for the damage in a quasi-in-situ manner. It was found that the low-energy ion-beam induced radiosensitivity of the four bases shows the sequence G > T > C > A, wherein the possible mechanism was also discussed. (C) 2014 Elsevier B.V. All rights reserved.

We investigated the effects of MgSO4 on L-lactic acid production by the Rhizopus oryzae strain RLC41-6 in order to improve the production rate and quality of L-lactic acid. We also studied the effects of MgSO4 on intracellular lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH) activity. Different concentrations of MgSO4 were added to the fermentation medium before culture of R. oryzae at 36 degrees C for 36 h. L-lactic acid concentration was determined by reverse phase high performance liquid chromatography, and the activity and intracellular expression of LDH and ADH were examined via polyacrylamide gel electrophoresis and kinetic methods. Although increasing MgSO4 concentrations led to increased lactic acid production by R. oryzae, MgSO4 had no effect on LDH expression or activity. Furthermore, MgSO4 promoted mycelium growth and inhibited ADH activity. With an initial MgSO4 concentration of 0.075%, maximum mycelium production of 36.8 g/L was achieved and L-lactic acid was the only fermentation product, at similar to 138 g/L with a 92% conversion rate. An appropriate concentration of MgSO4 can inhibit the conversion of pyruvic acid into malic acid and fumaric acid as well as both ADH activity and alcohol synthesis, thereby enhancing the conversion of glucose into lactic acid in R. oryzae.

Nitrogen fertilizer unabsorbed by crops eventually discharges into the environment through runoff, leaching and volatilization, resulting in three-dimensional (3D) pollution spanning from underground into space. Here we describe an approach for controlling nitrogen loss, developed using loss control fertilizer (LCF) prepared by adding modified natural nanoclay (attapulgite) to traditional fertilizer. In the aqueous phase, LCF self-assembles to form 3D micro/nano networks via hydrogen bonds and other weak interactions, obtaining a higher nitrogen spatial scale so that it is retained by a soil filtering layer. Thus nitrogen loss is reduced and sufficient nutrition for crops is supplied, while the pollution risk of the fertilizer is substantially lowered. As such, self-fabrication of nano-material was used to manipulate the nitrogen spatial scale, which provides a novel and promising approach for the research and control of the migration of other micro-scaled pollutants in environmental medium.

Severe eutrophication of surface water has been a major problem of increasing environmental concern worldwide. In the present study, economic plant annual ryegrass (Lolium multiflorum) was grown in floating mats as an economic plant-based treatment system to evaluate its potential after ion implantation for removing nutrients in simulated eutrophic water. The specific weight growth rate of L. multiflorum with ion implantation was significantly greater than that of the control, and the peroxidase, nitrate reductase, and acid phosphatase activities of the irradiated L. multiflorum were found to be greater than those plants without ion implantation. Higher total nitrogen (TN) and total phosphorus (TP) removal efficiencies were obtained for the L. multiflorum irradiated with 25 keV 5.2 × 1016 N+ ions/cm2 and 30 keV 4.16 × 1016 N+ ions/cm2, respectively (p < 0.05). Furthermore, the nitrogen and phosphorus contents in the plant biomass with ion implantation were also greater than those in the control and were positively correlated with TN and TP supplied. L. multiflorum itself was directly responsible for 39–49 and 47–58 % of the overall N and P removal in the experiment, respectively. The research results suggested that ion implantation could become a promising approach for increasing phytoremediation efficiency of nutrients from eutrophic water by L. multiflorum.

Energetic particles exist ubiquitously and cause varied biological effects such as DNA strand breaks, lipid peroxidation, protein modification, cell apoptosis or death. An emerging biotechnology based on ion-beam technique has been developed to serve as an effective tool for mutation breeding of crops and microbes. In order to improve the effectiveness of ion-beam biotechnology for mutation breeding, it is indispensible to gain a better understanding of the mechanism of the interactions between the energetic ions and biological systems which is still elusive. A new trend is to conduct more comprehensive research which is based on micro-scaled observation of the changes of the cellular structures and compositions under the interactions. For this purpose, advanced synchrotron FTIR (s-FTIR) microscopy was employed to monitor the cellular changes of single fungal hyphae under irradiation of α-particles from 241Am. Intracellular contents of ROS, MDA, GSSG/GSH and activities of CAT and SOD were measured via biochemical assay. Ion-irradiation on Rhizopus oryzae causes localized vacuolation, autolysis of cell wall and membrane, lipid peroxidation, DNA damage and conformational changes of proteins, which have been clearly revealed by the s-FTIR microspectroscopy. The different changes of cell viability, SOD and CAT activities can be explained by the ROS-involved chemical reactions. Evidently, the elevated level of ROS in hyphal cells upon irradiation plays the key role in the caused biological effect. This study demonstrates that s-FTIR microspectroscopy is an effective tool to study the damage of fungal hyphae caused by ionizing radiation and it facilitates the exploit of the mechanism for the interactions between the energetic ions and biological systems.

Although non-thermal discharge plasma is more and more applied in biological field, the molecular mechanisms of plasma acting on biomolecules are still unclear, which are indispensable for understanding the plasma-induced biological effects. In this work, discharge plasma at the gassolution interface was employed to irradiate on reduced glutathione (GSH), the most abundant low molecular weight thiol-containing antioxidant in cells. Through Raman spectroscopy, both the irreversible damage and reversible conversion of GSH to oxidized glutathione (GSSG) were monitored in a non-destructive fashion, so that the reaction kinetic processes through multi-pathways could be evaluated quickly and quantitatively. Based on the experimental data, the reaction mechanism was discussed.

OBJECTIVE:To improve the yield and quality of L-lactic acid by Rhizopus oryzae, we aim to understand the relationship between inorganic salts utilization and the L-lactic acid metabolism of the strain RLC41-6, through systematic analysis of the effects of zinc ion concentration on the production of L-lactic acid and the Lactic Dehydrogenase (LDH) activity.METHODS:Rhizopus oryzae was cultured at 36 degrees C for 36h with different quantity of ZnSO4 in fermentation medium. The fermentation products were monitored by reversed-phase high performance liquid chromatography (RP-HPLC), LDH isoenzyme composition in the cell was analysed by non-denatured polyacrylamide gel electrophoresis (PAGE).RESULTS:Our results showed that the concentration of ZnSO4 in medium could modulate the expression of LDH isoenzyme except LDH1, especially stimulated the expression of LDH4 and LDH5. When initial concentration of ZnSO4 is above 0.02%, the LDH4 and LDH5 reached the highest level. However, the activity of LDH was inhibited by higher concentration zinc ion in extracellular environment. When ZnSO4 concentration is 0.02%, LDH activity reaches its maximum 200U/mL, the HPLC assay showed only L-lactic in the fermentation products (137 g/L), while the conversion rate of glucose to lactic acid is 91%.CONCLUSION:Zinc ion can regulate the metabolic processes of Rhizopus oryzae and modulate the types of the final fermentation products. An optimal concentration of ZnSO4 can not only facilitate the LDH expression but also prevent pyruvate from transformation into the malic acid and fumaric acid during the metabolism process, thereby enhance the metabolism of glucose to lactic acid of Rhizopus oryzae.

Cover: Application of discharge plasma caused convertible reaction between the reduced and oxidized form of glutathione, one intrinsic antioxidant in cell which prevents damage to important cellular components caused by reactive oxygen species. Raman spectroscopy was employed to probe the process in a non-invasive way by monitoring the 508 cm-1 and 2567 cm-1 Raman bands corresponding to (SH) and (SS) vibrations, respectively. This study sets up an example to quantitatively investigate the oxidative stress effect on the sulfhydryl active center in proteins and the antioxidant system of biological organisms. Further details can be found in the article by Q. Huang et.al. on page 181.

Activated sludge process is generally applied on biological wastewater treatment. The Activated sludge Model No.1 (ASM1) is a mathematical description of biochemical processes in the reactor for nitrogen and chemical oxygen demand removal. ASM1 model was used to simulate the concentrations of components in leaving water with single-stage completely mixed CSTR (continuously stirred tank reactor) assumed. According to the concentrations of components in entering water of published data, curve simulation results of SNH and SNo show that the nitrogen removal process follows the nitrification-denitrification principle. And the steady-state results of 10 kinds of selected components indicate the simulation of the components concentration of leaving water is relatively accurate,and the nitrogen removal effect is obvious. The simulation system can provide effective technical support for wastewater treatment of actual plant.