Deciphering the effect of sodium dodecylbenzene sulfonate on up-flow anaerobic sludge blanket treatment of synthetic sulfate-containing wastewater

• UASB reactor can work efficiently with high COD/SO₄^2- ratios when SDBS exists. • Outcome of the competition between SRB and MPA was affected by SDBS. • Presence of SDBS makes methanogens with H₂/CO₂ as a substrate dominant. • Microbial diversity decreases in the presence of SDBS. In this study, the effects of organic sulfur on anaerobic biological processes were investigated by operating two up-flow anaerobic sludge blanket (UASB) reactors with sodium dodecylbenzene sulfonate (SDBS) as a representative of organic sulfur. The results indicated that the specific methanogenic activity (SMA) and chemical oxygen demand (COD) removal efficiency of R2 (with SDBS added) were higher than those of R1 (without SDBS) when the COD/SO₄²⁻ ratio was above 5.0. However, when the COD/SO₄²⁻ ratio was lower than 5.0, the sulfate reduction efficiency of R2 was higher than that of R1. These results and the observed SDBS transformation efficiency in anaerobic reactors indicate that low concentrations of SDBS accelerate methane production and the continuous accumulation of SDBS does not weaken the reduction of sulfate. Similarly, the calculated electron flux for a COD/SO₄²⁻ ratio of 1.0 indicates that the utilization intensity of electrons by sulfate-reducing bacteria (SRB) in R2 was 36.48% higher than that of SRB in R1 and exceeded that of methane-producing archaea (MPA) under identical working conditions. Moreover, the addition of SDBS in R2 made sulfidogenesis the dominant reaction at low COD/SO₄²⁻, and Methanobacterium and Methanobrevibacter with H₂/CO₂ as the substrate and Desulfomicrobium were the dominant MPA and SRB, respectively. However, methanogenesis was still the dominant reaction in R1, and Methanosaeta with acetic acid as the substrate and Desulfovibrio were the dominant MPA and SRB, respectively.     

镉在北京褐潮土中对玉米幼苗及其根际微生物的毒性效应

通过温室盆栽实验,研究了镉在北京褐潮土中对玉米(品种郑单958)幼苗的毒性效应及其生物富集特性,并通过聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术,探讨了镉对玉米根际微生物群落结构的影响。结果表明,高浓度(>100mg·kg-1)镉对玉米幼苗的生长发育有明显的抑制作用,北京褐潮土中镉引起玉米幼苗株高下降1/2的效应浓度(EC50)为654.6mg·kg-1,引起玉米根部和地上部干质量下降1/2的EC50分别为323.6和110.2mg·kg-1,玉米幼苗地上部生物量(干质量)可作为评价重金属生态毒性的适宜终点。玉米幼苗对镉有一定的吸收累积效应,镉在玉米幼苗各组织中的浓度分布为根>茎>叶,其中根部对镉有一定的富集作用(生物富集系数BAF>1)。镉污染可引起玉米根际微生物群落结构发生改变,高浓度(1000mg·kg-1)镉可导致部分微生物种群数量减少甚至完全消失,表明镉污染可对植物幼苗、植物根际微生物以及植物-微生物之间的相互作用造成重要的干扰和威胁。     

Genotoxicity study of phenol and o-cresol using the micronucleus test and the comet assay

Phenol and cresols are common toxic environmental pollutants. In this study, the micronucleus assay and the alkaline single cell gel electrophoresis (SCGE) technique have been used to investigate the genotoxic activity of phenol and o-cresol. The result of experiments revealed that phenol and o-cresol were both evident genotoxins, and the genotoxic activity of o-cresol was stronger. In the micronucleus assay, phenol and o-cresol could both cause a significant increase in the micronucleus (MN) frequencies (p?p?p?p?相似文献   

改进的QuEChERS-高效液相色谱法测定水产品中16种多环芳烃

采用改进的QuEChERS,对水产样品进行提取、净化,用高效液相色谱仪-荧光/紫外检测器串联检测,建立了同时测定水产品中16种多环芳烃的高效液相色谱分析方法.样品经乙腈提取,Florisil+C18小柱净化,Waters PAH色谱柱分离,以乙腈-水为流动相进行梯度洗脱,外标法定量.本方法中,16种多环芳烃在各自相应浓度范围内线性关系良好,相关系数不低于0.999,检出限为0.1—3.6μg·kg-1.采用该方法在鲤鱼、对虾和牡蛎中进行加标回收实验,回收率在75.0%—118.2%范围内,相对标准偏差(RSD)为2.6%—13.7%.应用本方法对环渤海湾的水产样品进行了调查分析,发现部分样品中含有PAHs,含量为2.11—147μg·kg-1,为下一步开展相关风险评估工作打下了良好工作基础.     

Fhhh工程菌株降解PTA废水动力学研究

研究了工程菌株Fhhh降解精对苯二甲酸(PTA)石化废水的动力学.将测得的Fhhh降解废水的6项动力学参数值、废水自然参数值、废水排放标准控制值,输入环境生物技术信息学软件(Ebis)进行计算.结果表明,来源于3种保存方法的Fhhh菌株中,所需反应器的最小体积(V_min)为1309m³,比降解率(q_A)的最高数值为0.0136h^-1,是土著菌YZ1的4倍,高于国内外同类研究的4项数值,低于同类研究的2项数值.结果表明,Fhhh工程菌株具有降解PTA废水的显著优势.     

碳中和目标下黄河流域产业结构对生态环境的影响及展望

黄河流域生态环境本底脆弱,长期以来面临着水资源短缺、土地荒漠化、水土流失等诸多严峻的生态环境问题。黄河流域以矿业、能源和重化工业粗放式开发为主的低端产业结构,对水资源消耗巨大,产生的污染较为严重,对流域生态环境影响大。在碳中和战略目标下,进行产业结构低碳转型和产业升级、加强水资源保护和合理利用、调整农业农村发展模式、平衡区域发展差距已成为黄河流域产业结构调整的重要方向,也是实现黄河流域生态保护和高质量发展战略的必由之路。     

零价铁活化过硫酸钠深度处理电镀添加剂生产废水

采用零价铁(ZVI)活化过硫酸钠(PS)产生·SO_4~-,以·SO_4~-为氧化剂深度处理电镀添加剂生产废水。考察了废水p H、n(ZVI)∶n(PS)、c(S_2O_8~(2-))和反应温度对废水COD去除率的影响。实验得出废水处理的最佳工艺条件:废水p H为5.0,n(ZVI)∶n(PS)=1.00,c(S_2O_8~(2-))=15 mmol/L,反应温度为50℃。在此最佳工艺条件下反应60 min,COD去除率达到76.8%,出水COD约为42 mg/L,满足GB 18918—2002《城镇污水处理厂污染物排放标准》的一级标准要求。     

The bioaerosols emitted from toilet and wastewater treatment plant: a literature review

Environmental Science and Pollution Research - The aerosols harboring microorganisms and viruses released from the wastewater system into the air have greatly threatened the health and safety of...     

A ventilation cooling shirt worn during office work in a hot climate: cool or not?

The aim of the study was to identify whether a ventilation cooling shirt was effective in reducing heat strain in a hot climate. Eight female volunteers were exposed to heat (38?°C, 45% relative humidity) for 2?h with simulated office work. In the first hour they were in normal summer clothes (total thermal insulation 0.8?clo); in the second hour a ventilation cooling shirt was worn on top. After the shirt was introduced for 1?h, the skin temperatures at the scapula and the chest were significantly reduced (p?<?0.05). The mean skin and core temperatures were not reduced. The subjects felt cooler and more comfortable by wearing the shirt, but the cooling effect was most conspicuous only during the initial 10?min. The cooling efficiency of the ventilation shirt was not very effective under the low physical activity in this hot climate.     

香烟、电子烟自由燃烧烟雾中挥发性有机物的排放特征

采用密闭实验箱开展香烟、电子烟的自由燃烧实验,利用Tenax吸附管采集箱内烟气中挥发性有机物(VOCs)样品,采用热解吸—气相色谱/质谱方法测定108种VOCs化合物,定量研究香烟、电子烟自由燃烧烟雾中VOCs的浓度、种类、特征物及排放率,结果表明:(1)香烟自由燃烧烟雾108种VOCs中臭氧前体物(PAMs)、空气毒...