Acid-assisted hydrothermal synthesis of nanocrystalline TiO2 from titanate nanotubes: Influence of acids on the photodegradation of gaseous toluene

In order to efficiently remove volatile organic compounds (VOCs) from indoor air, onedimensional titanate nanotubes (TiNTs) were hydrothermally treated to prepare TiO₂ nanocrystals with different crystalline phases, shapes and sizes. The influences of various acids such as CH₃COOH, HNO₃, HCl, HF and H₂SO₄ used in the treatment were separately compared to optimize the performance of the TiO₂ nanocrystals. Comparedwith the strong and corrosive inorganic acids, CH₃COOH was not only safer andmore environmentally friendly, but also more efficient in promoting the photocatalytic activity of the obtained TiO₂. Itwasobserved that the anatase TiO₂ synthesized in 15 mol/L CH₃COOH solution exhibited the highest photodegradation rate of gaseous toluene (94%), exceeding that of P25 (44%) by a factor ofmore than two. The improved photocatalytic activity was attributed to the small crystallite size and surface modification by CH₃COOH. The influence of relative humidity (20%-80%) on the performance of TiO₂ nanocrystals was also studied. The anatase TiO₂ synthesized in 15 mol/L CH₃COOH solution was more tolerant tomoisture than the other TiO₂ nanocrystals and P25.     

Diversity and biogenesis contribution of sulfate-reducing bacteria in arsenic-contaminated soils from realgar deposits

Environmental Science and Pollution Research - Microbial sulfate reduction, a vital mechanism for microorganisms living in anaerobic, sulfate-rich environments, is an essential aspect of the sulfur...     

Influence of different inoculation densities of black soldier fly larvae (Hermetia illucens) on heavy metal immobilization in swine manure

The disposal of organic waste by the biocomposting of black soldier fly larvae (BSFL) has drawn broad attention. However, the discrepancies in heavy metal immobilization between BSFL biocomposting with different inoculation densities and aerobic composting need to be further researched. In this study, BSFL with inoculation densities of 0.08%, 0.24% and 0.40% was added to swine manure to investigate its influence on heavy metal bioaccumulation and bioavailability. The physicochemical properties, BSFL growth performance and amino acid contents were measured. The results showed that the germination index, total prepupal yield and bioavailable fraction removal rate (%) of Cr and Pb at an inoculation density of 0.40% of BSFL were the highest among all of the BSFL biocomposting groups. Although the bioaccumulation factor and heavy metal (Cd, Cr, Cu and Zn) concentrations of the BSFL body from swine manure with inoculation densities of 0.24% and 0.40% of BSFL were similar, the BSFL inoculation density of 0.40% had the best absorption effect on these heavy metals in terms of total prepupal yield. Therefore, this study provides a basis for exploring the optimal inoculation density of BSFL biocomposting to reduce the harmful effects of heavy metals in swine manure.

     

What are the disease burden and its sensitivity analysis of workers exposing to Staphylococcus aureus bioaerosol during warm and cold periods in a wastewater treatment plant?

Environmental Science and Pollution Research - Biological treatment in wastewater treatment plants releases high amounts of pathogenic bioaerosols. Quantitative microbial risk assessment is a...     

基于入口NOx质量浓度修正的脱硝系统多模型预测控制策略及其应用案例

建立不同锅炉工况下基于欧式距离聚类的总给煤量长短期记忆神经网络预测模型,对入口处的NO_x质量浓度数据进行修正,其验证集上的均方根误差为3.53 mg·m^-3。该结果优于常见的回归方法深度神经网络与随机森林回归的预测结果。以此为基础,研究了基于入口NO_x质量浓度修正的多模型预测控制(MMPC),设计并进行了脱硝系统仿真。仿真结果表明,与原有控制条件相比,基于入口NO_x质量浓度修正的MMPC策略使脱硝系统出口NO_x质量浓度波动幅度减小了63.7%,并能满足出口质量浓度指标为40 mg·m^-3时的控制要求,实现卡边控制。现场工程应用结果表明：在高、中、低负荷正常运行的工况条件下,入口修正-MMPC策略可将出口NO_x质量浓度波动分别控制在±10.6 mg·m⁻³、±5.5 mg·m⁻³、±4.9 mg·m⁻³,以标准差来衡量波动幅度即分别减小了53.4%、74.7%、64.6%,此控制水平优于原有控制效果;在出口NO_x质量浓度易超标并出现高浓度氨逃逸的快速变负荷工况下,升、降负荷出口NO_x质量浓度波动分别控制在±6 mg·m⁻³、±5 mg·m⁻³,此控制水平仍优于原有控制效果。本研究的入口修正-MMPC控制策略可实现不同负荷、工况下的喷氨控制,减小出口NO_x波动幅度,降低后续设备低温腐蚀的风险,从而提高SNCR/SCR联合脱硝系统运行的经济性和安全性。     

Male reproductive toxicity involved in spermatogenesis induced by perfluorooctane sulfonate and perfluorooctanoic acid in Caenorhabditis elegans

Environmental Science and Pollution Research - As a persistent organic pollutant, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have gained increasing research attention over...     

城市垃圾卫生填埋场废气产生量及主要污染因子的确定

城市生活垃圾以其特有的分散、巨量、恶臭、肮脏等特性,使环境污染问题显得更加突出、复杂,因此建造垃圾填埋场势在必行。本文以城市垃圾卫生填埋场址的环境影响评价为基础,对垃圾填埋场恶臭气体产生量及其影响强度进行科学的分析与探讨,为垃圾场废气的治理及环境管理提供科学依据。1　垃圾卫生填埋废气产生量分析1.1　废气污染物的产生及特征根据有关实验及文献资料〔1,2〕,填埋场中废气大致由50%～60%的CH4,40%～50%的CO2和一定量的NH3、N2、H2S等物质组成。填埋场产生的废气成份应根据生产过程来确定,在填埋初期两周内氮、氧的含量比…     

农药残留速测技术研究进展

本文综述了国内外农药快速检测技术的研究状况。在速测技术中 ,色 -质联用分析法已发展得比较成熟 ,所得结果比较可靠 ,但该法的测定时间仍较长 ;免疫分析法具有简单、快速、价廉、特异性高、需样品量少等优点 ;生物传感器法更方便、快捷。     

曝气-絮凝处理垃圾渗滤液研究

通过现场处理 ,对垃圾渗滤液的曝气 -絮凝处理进行了研究。结果表明该方法对渗滤液的色度、COD、总磷去除率达 80 %以上 ,对氨氮去除率达 60 %以上。在此基础上提出了最优综合控制指标     

环境污染物的分子毒理机制研究进展

以分子生物学技术为基础研究污染物的毒理机制．从分子水平揭示了污染物毒作用的本质。综述了国内外分子毒理机制的研究进展。详细阐述了毒理芯片、单细胞凝胶电泳等分子生物学技术应用与毒理学研究中的特点、应用前景以及存在的问题。提出了分子毒理机制今后的研究方向。