This study presents a microbial activation strategy to repurpose coal gangue (CG) for enhancing soil quality in aeolian sandy soil. Phosphate-solubilizing bacteria (20−3) and nitrogen-fixing bacteria (SGD06) were employed to produce two microbially activated CGs (CG20-3 and CGSGD06). Adsorption experiments elucidated their colonization mechanisms on CG, while seed germination and pot trials with pakchoi validated remediation efficacy. Even after pakchoi harvest, both CG20-3 and CGSGD06 significantly increased soil bioavailable nutrients by 1.13–6.86-fold. CGSGD06 exhibited superior nitrogen delivery through biological fixation, providing 82.39% higher available nitrogen than CG20-3. Conversely, CG20-3 showed faster adsorption kinetics and stronger binding capacity. Both strains mediated nutrient liberation via acid-driven dissolution of CG clay minerals, including kaolinite, muscovite, and phosphates. Treated soils enhanced pakchoi germination (3.08%) and biomass (1.14–1.89-fold) through improved plant resistance and biochemical indicators, namely ascorbic acid, chlorophyll, and soluble sugar. The activated CGs reshaped the rhizosphere bacterial community and stimulated the secretion of organic acids, phytohormones, and key enzymes, collectively establishing a synergistic growth-promoting system. Additionally, rhizospheric micronutrient bioavailability increased 4.52–43.15-fold, and key soil enzyme activities were upregulated 1.42–267-fold. This work provides a preliminary basis for using microbially activated CG as a potential amendment for aeolian sandy soil, highlighting opportunities for solid waste valorization and soil restoration under controlled conditions.

Soil acidification limits the sustainable development of agroecosystems globally, heavy metal hazards will be further amplified in acidic soils. However, few studies have been reported on the effects of bacteria on the growth of vegetable crops in heavy metal-contaminated acidic soils. Thus, this study investigated the effect of a pre-screened strain of heavy metal-resistant phosphate-solubilizing bacteria (OPDB3-6–1) on the physicochemical properties, heavy metal fraction composition, growth of Brassica rapa var. chinensis L. (siyueman), antioxidant enzyme activities, and heavy metal enrichment capacity of heavy metal contaminated acidic soils. The results showed that OPDB3-6–1 improved the acidic soil and elevated soil AP and AK contents, optimizing the soil microenvironment. OPDB3-6–1 reduced the malondialdehyde content in plants, and increased the chlorophyll content of siyueman, thus alleviating the oxidative stress of heavy metals on siyueman and improving the photosynthetic efficiency, which further promoted the growth of siyueman and the accumulation of biomass. In addition, OPDB3-6–1 altered soil heavy metal fractions, inhibited the enrichment of heavy metals in siyueman. Compared with the CK, OPDB3-6–1 reduced the contents of Pb, Cu, and Cd in the edible part of siyueman by 41.96

While biochar (BC) is widely acknowledged for mitigating environmental risks posed by PAHs through adsorption-stabilization, its long-term performance and impact on subsequent microbial degradation remain unclear. This study systematically investigated the influence of aging on adsorption, speciation distribution and bio-accessibility of benzo[a]anthracene (BaA, a tetracyclic PAH) on BC by simulating natural weathering processes. The results revealed that aging significantly reduced BC's capacity for BaA adsorption, while distinct interaction mechanisms led to diverse speciation distributions of sorbed BaA. Specifically, weak surface interactions govern the formation of desorbing BaA; it-it stacking mediated by aromatic skeletons and graphite-like structures constitute the key mechanism for non-desorbing BaA; and hydrogen bonding with higher binding energy, formed by oxygen-containing functional groups, results in the production of bound-residue BaA. Furthermore, the well-developed porous structure of BC entrapped a considerable proportion of non-extractable BaA. Notably, aging enhanced the stability of BaA adsorption by Aged-BC by expanding BC's porous structure and introducing oxygen-containing functional groups, as evidenced by the bound-residue and non-extractable BaA contents being 38.2 % and 5.1 % higher than those in BC, respectively. Microbial degradation experiments demonstrated that the inoculated Stenotrophomonas maltophilia (strain HBN) achieved degradation rates of 30.2 % and 63.3 % for desorbing, 78.2 % and 89.8 % for non-desorbing, 48.0 % and 63.2 % for bound-residue BaA on BC and Aged-BC within 14 days. Our findings highlight the dual role of BC in stabilizing PAHs and allowing microbial utilization of sorbed fractions, providing a theoretical foundation for developing biocharmicrobe synergistic remediation strategies for PAH-contaminated soils.

The biochars of WP300, WP500, and WP700 were prepared by pyrolyzing walnut green husk under 300℃, 500℃, and 700℃ with the oxygen-free condition for removing Pb2+, Cu2+, and Cd2+ in an aqueous solution. The results revealed that WP500 prepared under the medium pyrolysis temperature achieved the best adsorption performance for heavy metals, and the highest removal efficiency was reached when the solution pH was 8, in which the removal efficiency of Pb2+, Cu2+, and Cd2+ were 97.87%, 99.78%, and 71.15%, respectively. The required biochar dosage for heavy metal removal varied under different adsorption conditions. In the single-metal system, the optimal dosage for WP500 in the Pb2+, Cu2+, and Cd2+ solutions was 1.3 g·L-1, 2.1 g·L-1, and 1.9 g·L-1, respectively, whereas in the pollution metals system, the optimal biochar dosage was 5.1 g·L-1. In addition, the adsorption capacity of WP500 for the three heavy metals followed the order of Pb2+>Cu2+>Cd2+ under the single and combined-metals system, indicating that there were no synergistic or antagonistic effects among these three adsorbates. The fitting results of the adsorption isotherm model suggested that various immobilization methods existed in adsorption process between WP500 and Pb2+, Cu2+, and Cd2+. The kinetic fitting results suggested that the main reaction between WP500 and Pb2+, Cu2+, and Cd2+ was chemical adsorption. The mechanisms of WP500 for heavy metals involved pore-filling, electrostatic attraction, ion-exchange, mineral precipitation, complexation, and π-π electron donor-accepter interaction. To conclude, this study offered a new insight for the resource utilization of the waste walnut green husk.

为了探讨生物炭固定化硫酸盐还原菌对镉(Cd2+)污染土壤的钝化修复效果,以制备的小麦秸秆生物炭为载体固定硫酸盐还原菌,研究不同修复剂生物炭(XM700)、硫酸盐还原菌(SRB15-3-2)和生物炭固定化硫酸盐还原菌(IBXM700)对Cd2+污染土壤的钝化修复效果.结果表明,与XM700组和SRB15-3-2组相比,IBXM700组的修复效果最好(p＜0.05),不同Cd2+浓度污染土壤修复45 d后,与CK组对比,IBXM700组Cd可交换态含量显著降低了 31.26％,残渣态含量提高了 91.20％;同时,IBXM700组土壤pH值提升0.37,速效磷、速效钾含量分别提升了 37.86％、57.29％,土壤蔗糖酶、脲酶、碱性磷酸酶和过氧化氢酶活性分别提升了 50.22％、52.45％、11.61％和28.03％.研究表明,IBXM700能够有效钝化修复Cd污染土壤,提升土壤肥力,在土壤修复领域具有很大潜力.

In this study, a bio-composite (IBWS700) was prepared using inorganic phosphate-solubilizing bacteria (iPSB), which were immobilized on biochar produced from wheat straw (WS700). Further, the bio-remediation effects of the composite for lead (Pb) in soil were also investigated. The presence of different Pb species, physicochemical properties, enzyme activities, and immobilization mechanisms of Pb in soil were also evaluated. Compared to free iPSB and biochar, IBWS700 significantly decreased the lead bio-availability whereas increased the residual fraction, also affected available phosphorus (AP), cation exchange capacity (CEC), organic matter (OM) and activity of urease, alkaline phosphatase, sucrase and catalase. Interestingly, the changes in the enzyme activity, AP and OM performed twice increases with increasing Pb concentration, which was rarely reported. The reason might be attributed to the reconstruction of bacteria communities with high Pb load. Further, the immobilization mechanisms mainly included bio-adsorption and bio-precipitation. SEM revealed that the surface of IBWS700 covered with a large number of heterogeneous colonization of iPSB and white stack after Pb2+ adsorption. FTIR spectra showed that O-H, C-O-P, CO, and C =C could play important roles in bio-adsorption. Moreover, XRD analysis indicated that bio-precipitates were mainly Pb5(PO4)3Cl. In general, the use of IBWS700 could effectively immobilize Pb2+ and improve soil quality.

以废白土为原料,分别在300、500℃和700℃条件下限氧热解制备废白土炭复合材料A&C300、A&C500、A&C700,采用H3PO4活化法对复合材料进行改性制备HA&C300、HA&C500和HA&C700,分析改性前后复合材料对恩诺沙星(ENR)的吸附效应,筛选出吸附效果最佳的材料;采用比表面积测试仪、扫描电镜-能谱分析、透射电镜、X射线光电子能谱仪及傅里叶红外光谱仪对筛选出的材料进行结构表征;研究改性复合材料吸附ENR的影响因素(ENR浓度、复合材料投加浓度和溶液pH),并结合吸附动力学、等温吸附模型和吸附热力学探究其对ENR的吸附作用机制.结果表明:未改性的废白土炭复合材料对ENR吸附效果较差,而采用H3PO4改性后的复合材料对ENR吸附效果均有所提升,其中HA&C300吸附效果最佳;与A&C300相比,HA&C300表面官能团丰富度和含氧官能团数量增加,疏水性增强,比表面积和总孔容分别为45.72 m2·g-1和0.10 cm3·g-1,分别是A&C300的1.54倍和1.59倍;当ENR初始浓度为10 mg·L-1时,HA&C300对ENR吸附的最佳参数为投加浓度0.5 g·L-1、pH 6,此时去除率最高达到92.34％,是A&C300去除率的2倍,最大吸附量达66.79 mg·g-1.HA&C300对ENR的吸附过程符合拟二级动力学方程和Freundlich模型,吸附过程主要受控于化学吸附,为自发的吸热反应,吸附机制包括氢键、π-πEDA、疏水作用和孔径填充.

以宝鸡凤县某铅锌尾矿库及周边农田表层土壤为研究对象,测定样品中重金属Pb、Cd、Hg、Zn等的含量,采用单因子污染指数(Pi)、内梅罗综合污染指数(P综)及Hakanson生态风险指数(RI)确定土壤污染状况的基础上,结合正定矩阵因子(PMF)受体模型,定量解析农田土壤重金属的来源.结果表明,农田土壤中Pb、Cd、Hg、Zn、Cu、As平均值含量分别是64.69mg ? kg-1、0.23mg.kg-1、0.18mg·kg-1、104.42mg·kg-1、37.69mg·kg-1、14.33mg·kg-1,其均值含量分别是陕西省土壤元素背景值的5.73、2.56、2.00、1.84、1.76、1.28倍.内梅罗综合污染指数显示,农田土壤中度及重度污染样点比例分别为41.03％和38.46％.Hakanson生态风险指数分析表明,农田土壤中76.92％的样点属强及以上风险等级,Pb、Cd、Hg为其主要生态风险因子.正定矩阵因子受体模型解析结果显示,源1主要载荷As和Zn,对其贡献率分别为100％和63.3％,为农业、铅锌选矿和交通活动三因素混合源;源2对Ni、Cr、Cu的载荷率分别为100％、87.4％、69.5％,为自然源;源3主要对土壤造成Hg污染,其贡献率为66.1％,为化石燃烧释放源;源4为铅锌选矿和交通活动混合源,对Cd解释率为64.0％;源5对农田土壤Pb的载荷率为86.6％,为铅锌工业活动源.

土地利用空间格局变化反映土地利用合理性和生态环境情况.以位于农牧业交错带的生态环境脆弱区陕北榆林市为研究区,运用核密度分析法表达土地利用空间格局变化,采用土地利用动态度、土地利用综合动态度、土地利用变化强度、土地利用转移矩阵指数分析榆林市近40 a的土地利用变化速度、强度、结构及其影响因素.结果表明:榆林市近40 a土地利用变化以耕地面积减少、建设用地大幅度增加和未利用地减少为主.东南部耕地密度等级降低,西南部呈现相反的变化趋势;林地呈"多核心增长";草地高密度核心位于北部,等级升高;建设用地高密度核心位于西北部6个县区,增长幅度大.未利用地高密度核心为西北部毛乌素沙漠,斑块破碎化,沙地治理效果显著.政策因素、社会经济因素和人口因素的综合作用是影响土地利用空间格局变化的主要原因.退耕还林还草使得人地矛盾得到改善,减缓了水土流失;毛乌素沙地治理成效显著.未来发展需注重生态格局安全,以生态保护为前提,实现科学、绿色、可持续的高质量发展.

社区化新零售是城市商服圈与社区生活圈交织的特殊空间场域,其空间布局与选址值得深入探究.基于社区化新零售代表盒马鲜生在成都市12家门店官方服务范围的兴趣面数据及其周边社区、大学、餐饮、超市等兴趣点数据,综合运用文本分析、数理统计、空间分析等方法,探析盒马鲜生的空间布局、区位选址及其影响因素.研究发现:成都市盒马鲜生在市域空间上呈现以天府广场为中心的斜A状分布于中心城区中部二环至四环之间,数量呈现"高-低-低"分布;盒马鲜生以"点"状门店与"面"状服务区相结合的形式布局,服务范围形态受到社区布局、道路网络和地貌景观等的影响;区位选择倾向于服务范围内小区分布较多、具有一定基础人流量、地租相对适中、道路交通便捷程度高的商圈边缘或外围地带,地点上主要位于商场负一层;盒马鲜生主要服务对象为社区,其次为大学、企业、园区,主要竞争对手为综合超市、其他新零售门店和餐饮店铺,其规模、商品类型、空间分布等对盒马鲜生布局存在影响.最后,从宏观到微观多尺度整合的视角探索了社区化新零售空间布局的影响机制,提出了针对性的优化建议和未来的研究方向.

In the flue gas ammonia desulfurization process of the coal chemical industry, ammonium sulfate slurry in the desulfurization tower often foams and overflows, which wastes resources and pollutes the environment. The solution to this problem remains largely unknown. This paper aims to reveal the causes of foaming by analyzing foam composition, ammonia desulfurization process raw material source, and characteristics of the flue gas source of the coal chemical industries. It is seen that the organic carboxylate ammonium salt surfactant in the slurry was the main cause of ammonium sulfate slurry foaming. Moreover, due to ammonium sulfate crystals and ash in foam forming a skeleton to support the foaming structure, the foam was not easy to break. More importantly, an appropriate defoaming agent was screened and optimized by an ammonia desulfurization tower simulated device in the laboratory. The YLZ-3 compound defoaming agent, with the optimal defoaming efficiency, was obtained by combining a polyether siloxane copolymer, n-octyl alcohol, fumed silica, and deionized water. It had a good temperature stability and little influence on the ammonium sulfate slurry drying time. However, defoaming agent addition could affect the ammonium sulfate crystal form. The foam overflowing could be controlled by spraying the defoaming agent from the top of the tower. Thus, the problem of bubbling overflow of the ammonia desulfurization tower could be resolved very well.

分别在300、500℃和700℃下制备水稻、小麦和玉米秸秆生物炭,对比以不同类型生物炭为载体制备的炭基硫酸盐还原菌(SRB)对Cr(Ⅵ)的吸附效应,筛选出吸附效果最佳的炭基菌剂.采用扫描电镜、傅里叶红外光谱和比表面积测试仪对生物炭进行表征分析,研究了溶液pH、吸附时间、生物炭添加量和Cr(Ⅵ)初始浓度对炭基SRB吸附Cr(Ⅵ)的影响,并结合吸附动力学和等温吸附模型探讨其对Cr(Ⅵ)的吸附过程及作用机制.结果表明:以700℃限氧热解小麦秸秆(XM700)为载体制备的炭基SRB(IBXM700)对Cr(Ⅵ)的吸附效果最佳,其最佳吸附条件为pH=5、生物炭添加量0.6 g·100 mL-1、吸附时间24 h、Cr(Ⅵ)的初始浓度100 mg·L-1;IBXM700对Cr(Ⅵ)的吸附更符合拟一级动力学,以离子交换和表面物理吸附为主,以化学吸附作用为辅,其等温吸附符合Langmuir模型,属于单分子层吸附;SRB能还原SO 2-4为S2-,或分泌还原酶将Cr(Ⅵ)还原为Cr(Ⅲ),从而达到去除目的.研究表明,IBXM700去除Cr(Ⅵ)的主要机制为吸附作用与还原作用.

分别在300、500、700℃下限氧热解稻草、小麦和玉米秸秆制备生物炭,并以制备的生物炭为载体固定化硫酸盐还原菌(SRB),对比不同类型生物炭固定化SRB对Cd2+的吸附效果,筛选出吸附效果最佳的固定化SRB菌剂,并采用SEM、FTIR和BET对其进行表征分析;同时,研究溶液pH、吸附时间、生物炭添加量、Cd2+浓度对吸附效应的影响,并结合吸附动力学和等温吸附模型探究其对Cd2+的吸附过程及作用机理.结果表明,700℃限氧热解小麦秸秆生物炭固定化SRB菌剂(IBXM700)对Cd2+的吸附效果最佳;在pH=8、生物炭添加量为0.6 g(每50 mL溶液)、吸附时间为8 h、Cd2+初始浓度为40 mg·L-1条件下,IBXM700对Cd2+的吸附效果最佳,其吸附符合拟一级动力学模型,以离子交换和表面物理吸附为主,以化学吸附作用为辅,且符合Langmuir模型,表明是单分子层吸附;离子交换、沉淀可能是IBXM700吸附Cd2+的主要机制,阳离子-π作用为次要机制.

从地理学的视角探讨疫情传播与扩散的时空动态过程有助于实施精准防控.以近鄂高发省域安徽省为研究区,基于官方通报的病例数据与人工判读采集感染信息与轨迹数据以及相关POI数据,综合运用数理统计、空间分析等方法探究安徽省COVID-19疫情时空格局演变与影响因素.结果 表明:确诊病例的性别年龄结构呈现“菱形”,主要集中在20 ～ 59岁,峰值段为45 ～ 54岁,且以男性和本地感染为主;感染时序为“J”结构,以后期感染者居多.时间上可以大致分为“起伏增长期—急速衰退期—稳定扫尾期”3个阶段;患者从发病到确诊之间的时间间隔主要集中在2 ～7d.空间上呈“西北—东南”走向,主要集中在皖北和皖中地区;定点医院和疫情小区的空间分布存在显著差异;省外输入型病例主要来源地为湖北省和浙江省.影响因素分析表明,各县市确诊病例数量主要受人口密度、一般性公共预算支出和与武汉市距离等因素影响.最后,提出了几点针对性建议,并指出了未来努力方向.

以小麦秸秆和活性污泥为原料,在3种温度下热解制备生物炭,使用傅立叶红外光谱(FTIR)和扫描电镜(SEM)对其结构和性能进行表征,探究了以不同生物炭为载体,以解磷菌为固定化菌株制备的固定化微生物对Pb2+的吸附能力,同时研究了吸附时间和热解温度对固定化微生物吸附Pb2+的影响.结果表明:小麦秸秆生物炭较活性污泥生物炭的表面官能团更为丰富,且小麦秸秆生物炭的芳香化程度随热解温度升高而增加;随着热解温度的升高,小麦秸秆生物炭的微孔逐渐发展,孔壁变薄,孔隙结构更为发达;以700℃ 热解的小麦秸秆生物炭为载体制备的固定化微生物(IBWS700)对Pb2+的吸附量最高,对Pb2+的吸附量可达89.39 mg/g;IBWS700对Pb2+的吸附动力学符合准二级动力学方程;IBWS700对Pb2+的吸附可以用Langmuir模型较好地拟合.

Thirty-five organic phosphorus-degrading bacterial (OPDB) strains were screened from tailing-waste-contaminated soil. OPDB3-6-1 was selected based on its high ability to decompose organic phosphorus compounds and tolerance for heavy metals. OPDB3-6-1 was identified as Serratia marcescens by 16 s rDNA analysis. The immobilization effects of OPDB3-6-1 along with organic phosphorus compounds (rapeseed dregs) were examined in the remediation of heavy-metals-contaminated acidic soil. The results showed that inoculation of OPDB3-6-1 with rapeseed dregs in acidic heavy-metals-contaminated soil significantly reduced the bioavailability of Pb, Cd and Cu. In addition, the soil pH increased markedly, whereas the concentration of available phosphorus decreased over time. The reason may be that the phosphates released by OPDB3-6-1 reacted with the heavy metals in the soil. Furthermore, the mechanisms of the heavy metal immobilization by OPDB3-6-1 were investigated in this work. The data showed that OPDB3-6-1 could absorb heavy metals and its metabolites could precipitate heavy metals. Additionally, the bioprecipitation of each heavy metal was analyzed by X-ray diffraction (XRD), and the data showed that the bioprecipitations were mainly attributed to basic cupric chloride (Cu4(OH)6Cl2), cadmium carbonate (CdCO3), and pyromorphite (Pb5(PO4)3Cl). Moreover, the mechanisms of bio-adsorption were investigated by Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscope (SEM). We found that PO, P-OH, PO43−, and CO played an important role in the adsorption of heavy metals. Overall, the mechanisms for heavy metal immobilization mainly involve bio-adsorption and bioprecipitation, and the inoculation of heavy metal tolerant OPDB with organic phosphorus compounds may have good application prospects in heavy metal pollution control and acid soil improvement in the future.

Aim To investigate the vegetation dynamic changes in Qinling area with the reconstructed NDVI time series data.Methods Based on MODIS NDVI time series data from 2000 to 2009 in Qinling area,Asymmetric Gaussians algorithm(AG) was selected to reconstruct the time series data to reduce the negative impact of clouds,cloud shadow and atmospheric aerosols.Results ①The forest and shrub vegetation located in the hinterland of Qinling Mountains showed a higher stability in the past decade,while the cropland and mosaic cropland/non-crop vegetation located in northern slope of Qinling Mountain,as well as those areas surrounded by mountain residents,showed dramatically inter-annual fluctuation under the impact of human activities;②The cropland located in the areas of the hinterland of Qinling Mountains showed the most obvious improvement trend.The forest and shrub vegetation located in the hinterland of Qinling Mountain had some degree of improvement trend,which is relatively stable.While the vegetation distributed in the surrounding area of major cities had a significant degradation trend,especially around Xi′an city.Conclusion The vegetation in Qinling area showed overall improvement trend during the past decade.The stability of vegetation in this area showed significant reverse distribution characteristics with its distance from the proximity of human areas,which indicated that human activities play a very important role on the vegetation dynamic in Qinling area.

The electroless nickel plating for 45 steel articles with main salt NiSO4·6H2O,reducer NaH2PO2·H2O and compound complex agent in acid condition was researched.On the basis of single-factor experimental study of NiSO4·6H2O concentration,NaH2PO2·H2O concentration,NaAc concentration,complex agent A concentration,pH value and temperature of plating solution,etc,deposition rate as index,the various influencing factors were optimized systemically in virtue of orthogonal design methodology in electroless nickel plating process.The optimization results demonstrated that deposition rate would reach 17.38 μm/h on condition of 35 g/L NiSO4·6H2O concentration,30 g/L NaH2PO2·H2O concentration,10 g/L complex agent A concentration and pH value 6.0 in plating solution.The products prepared under optimal conditions could be satisfied with national standards.

目的:区域旅游发展水平存在差异,其表现是衡量指标之间的差异及指标组合关系的不同。试图发现区域内各指标之间的组合特点,分析各种类型特点并指出其转化路径及实现途径,给旅游开发提供实践参考和理论依据。方法:以国内的31省、市、自治区为单元,采用接待国内游客数量与国内旅游收入两项指标对区域内要素进行比较分析并按指标组合关系划分类型。结果:区域旅游发展指标间存在错位现象,并按其组合关系可以分为强同步区、弱同步区、优等错位区和劣等错位区。结论:区域旅游发展要素间关系复杂、出现多元化特征、区域间存在巨大差距等。

The ecological degradation has not only restricted regional economic development but also greatly affected the economy and social development for the middle and east China and even the whole country.Ecological degradation greatly affected urbanization in west China.From the analysis of current situation of lag and contradictions in the processes of urbanization,it can be found that the difficulties and problems in west urbanization are significant interactive,which further result in a vicious circle for aggregation ecological effect and aggregation economy,i.e.the vicious circle for proverty,population growth and environmental degradation.Furthermore,this vicious circle should be replaced by a new development model with better operation mechanism in order to enhance urbanization for west China.