Photocatalytic activity of Fe-doped CaTiO3 under UV-visible light

The photocatalytic degradation of methylene blue（MB） over Fe-doped CaTiO3 under UV-visible light was investigated. The as-prepared samples were characterized using X-ray diffraction（XRD）, scanning electron microscope（SEM） equipped with an energy dispersive spectrometer（EDS） system, Fourier transform infrared spectra（FT-IR）, and UV-visible diffuse reflectance spectroscopy（DRS）. The results show that the doping with Fe significantly promoted the light absorption ability of CaTiO3 in the visible light region. The Fe-doped CaTiO3 exhibited higher photocatalytic activity than CaTiO3 for the degradation of MB.However, the photocatalytic activity of the Fe-doped CaTiO3 was greatly influenced by the calcination temperature during the preparation process. The Fe-doped CaTiO3 prepared at500°C exhibited the best photocatalytic activity, with degradation of almost 100% MB（10 ppm）under UV-visible light for 180 min.     

硫酸盐还原菌包覆矿石控制酸性废水排放及碳源的优选研究

本研究基于实验室筛选、培养的硫酸盐还原菌(Sulfate-reducing bacteria,简称SRB)菌群,分别考察以麦芽糊精、污泥、乙醇、乳酸钠等为碳源时SRB的生长状况,同时模拟野外环境进行柱淋滤实验,分析在不同碳源作用下原位控制酸性矿山废水的效果.结果表明,采用这4种碳源时,SRB还原硫酸盐能力的大小依次为:...     

Fungal diversity in major oil-shale mines in China

As an insufficiently utilized energy resource,oil shale is conducive to the formation of characteristic microbial communities due to its special geological origins.However,little is known about fungal diversity in oil shale.Polymerase chain reaction cloning was used to construct the fungal ribosomal deoxyribonucleic acid internal transcribed spacer(r DNA ITS)clone libraries of Huadian Mine in Jilin Province,Maoming Mine in Guangdong Province,and Fushun Mine in Liaoning Province.Pure culture and molecular identification were applied for the isolation of cultivable fungi in fresh oil shale of each mine.Results of clone libraries indicated that each mine had over 50% Ascomycota(58.4%–98.9%)and 1.1%–13.5%unidentified fungi.Fushun Mine and Huadian Mine had 5.9% and 28.1% Basidiomycota,respectively.Huadian Mine showed the highest fungal diversity,followed by Fushun Mine and Maoming Mine.Jaccard indexes showed that the similarities between any two of three fungal communities at the genus level were very low,indicating that fungi in each mine developed independently during the long geological adaptation and formed a community composition fitting the environment.In the fresh oil-shale samples of the three mines,cultivable fungal phyla were consistent with the results of clone libraries.Fifteen genera and several unidentified fungi were identified as Ascomycota and Basidiomycota using pure culture.Penicillium was the only genus found in all three mines.These findings contributed to gaining a clear understanding of current fungal resources in major oil-shale mines in China and provided useful information for relevant studies on isolation of indigenous fungi carrying functional genes from oil shale.     

Removal kinetics of phosphorus from synthetic wastewater using basic oxygen furnace slag

Removal kinetics of phosphorus through use of basic oxygen furnace slag (BOF-slag) was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial pH, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant (k_obs) significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial pH, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage. A linear dependence of k_obs on total removed phosphorus (TRP) was established with k_obs = (3.51 ± 0.11) × 10^− 4 × TRP. Finally, it was suggested that the Langmuir–Rideal (L–R) or Langmuir–Hinshelwood (L–H) mechanism may be used to describe the removal process of phosphorus using BOF-slag.     

Removal kinetics of phosphorus from synthetic wastewater using basic oxygen furnace slag

Removal kinetics of phosphorus through use of basic oxygen furnace slag(BOF-slag)was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial p H, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant(kobs) significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial p H, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage.A linear dependence of kobson total removed phosphorus(TRP) was established with kobs=(3.51 ± 0.11) × 10- 4× TRP. Finally, it was suggested that the Langmuir–Rideal(L–R)or Langmuir–Hinshelwood(L–H) mechanism may be used to describe the removal process of phosphorus using BOF-slag.     

山海关区农村生态环境状况及保护对策

从山海关区农村生态环境现状出发,客观分析了农村生态环境存在的水体污染、土壤污染、水土流失等问题,以及影响农村生态环境的主要因素,如污水和垃圾的无组织排放、化肥和农药的不合理使用、基础设施差、监管缺位等,提出应从环保体制、环保意识、基础设施建设、自然资源保护、污染防治、强化监管等方面采取切实可行的措施,保护农村生态环境。     

台风‑风暴潮下海南地区砌体房屋物理脆弱性分析∗

海南省是我国台风登陆数量最多的省份之一。台风不仅直接对房屋建筑造成严重破坏,还可能会造成海面上涨引发风暴潮灾害,房屋在两种耦合灾害下易造成更加严重的损失。为探究台风?风暴潮作用下房屋的物理脆弱性,对海南省遭受台风灾害最严重的东海岸村镇砌体房屋进行了调研。首先基于受灾房屋资料的分析,确定了砌体房屋的建造特征和主要的破坏模式,并以风速和潮水淹没深度表征灾害强度,随后基于力学性能分析了砌体房屋的台风物理脆弱性,基于蒙特卡洛模拟建立了台风与台风风暴潮灾害之间的内在关系,基于定额清单法建立了台风?台风风暴潮灾害作用下房屋经济损失的计算方法。结果表明,砌体房屋在台风?风暴潮灾害下屋盖和墙体破坏严重,其中台风经济损失占主要部分,台风?风暴潮经济脆弱性曲线呈两段屈服平台分布。通过该地区砌体民房物理脆弱性分析,旨在为沿海地区防灾减灾工作提供一定的参考。     

含钛高炉渣合成复合肥料及大豆栽培实验研究

以含钛高炉渣为原料采用加热法制备肥料,以提高其溶解性能,使其中的营养元素转化为易被植物吸收利用的形式,并通过栽培实验研究了肥料对大豆生长状况、性状、产量和营养成分的影响。结果表明:炉渣中Mg、Ti、Fe的溶出率分别为88%、84%和75%,肥料中可被植物有效利用的元素有氮、硅、硫、钙、镁、铁和钛。该肥料可以使大豆产量、百粒重和叶片叶绿素含量明显增加;生育期缩短2 d;籽粒的氮、磷和钾含量显著增加,蛋白质和淀粉含量增加。施用该固态复合肥并未导致钒和铬等重金属元素在大豆体内的富集。     

生态建设与环境承载力研究

由于对生态建设的艰巨性和长期性、资金需求、阻力估计不足,生态建设过于口号化,我国生态建设存在诸多问题。从环境承载力的定义入手,分析了生态建设与环境承载力的关系,提出了当前生态建设应采取发展生态农业、生态工业、生态旅游、倡导绿色消费、加强污染综合治理等措施。     

Significant influences of TiO2 crystal structures on NO2 and HONO emissions from the nitrates photolysis

The emissions of NO₂ and HONO from the KNO₃ photolysis in the presence of TiO₂ were measured using a round-shape reactor coupled to a NO_x analyzer. TiO₂ played important roles in the emission flux density of NO₂ (R_NO2) and HONO (R_HONO), depending on crystal structures and mass ratios of TiO₂. R_NO2 and R_HONO significantly decreased with increasing the rutile and anatase mass ratios from 0 to 8 and 0.5 wt.%, respectively. Nevertheless, with further increasing the anatase mass ratio to 8 wt.%, there was an increase in R_NO2 and R_HONO. R_NO2 on KNO₃/TiO₂/SiO₂ had positive correlation with the KNO₃ mass (1–20 wt.%), irradiation intensity (80–400 W/m²) and temperature (278–308 K), while it had the maximum value at the relative humidity (RH) of 55%. R_HONO on KNO₃/TiO₂/SiO₂ slightly varied with the KNO₃ mass and temperature, whereas it increased with the irradiation intensity and RH. In addition, the mechanism for NO₂ and HONO emissions from the nitrates photolysis and atmospheric implications were discussed.