The effect of continuous exposure of copper on the properties and extracellular polymeric substances (EPS) of bulking activated sludge

Introduction  

This study investigated the effect of copper on chemical oxygen demand (COD) removal efficiency and on the properties (mainly settling and dewatering) and the composition of extracellular polymeric substances (EPS) when 20 mg/L Cu(II) was continuously dosed to a sequencing batch reactor (SBR) inoculated with activated sludge.     

Odor emission rate estimation of indoor industrial sources using a modified inverse modeling method

Odor emission rates are commonly measured in the laboratory or occasionally estimated with inverse modeling techniques. A modified inverse modeling approach is used to estimate source emission rates inside of a postdigestion centrifuge building of a water reclamation plant. Conventionally, inverse modeling methods divide an indoor environment in zones on the basis of structural design and estimate source emission rates using models that assume homogeneous distribution of agent concentrations within a zone and experimentally determined link functions to simulate airflows among zones. The modified approach segregates zones as a function of agent distribution rather than building design and identifies near and far fields. Near-field agent concentrations do not satisfy the assumption of homogeneous odor concentrations; far-field concentrations satisfy this assumption and are the only ones used to estimate emission rates. The predictive ability of the modified inverse modeling approach was validated with measured emission rate values; the difference between corresponding estimated and measured odor emission rates is not statistically significant. Similarly, the difference between measured and estimated hydrogen sulfide emission rates is also not statistically significant. The modified inverse modeling approach is easy to perform because it uses odor and odorant field measurements instead of complex chamber emission rate measurements.     

浅层地下水重金属元素的富集特征研究

以淮南市浅层地下水为研究对象,采集并测试了130个水样中Fe、Mn、Cu、Zn、Pb、Cd和M等元素的含量及相关指标.通过分析pH与重金属的相关性,得出了重金属在水中的富集特征,即VFe＞VCu＞VZn＞VPb＞VMn.利用主成分对7种重金属进行分类并分析其富集成因,最后将测试结果与土壤重金属含量相比较,确定了重金属元...     

铁炭-混凝沉淀-生化处理强酸性染料废水的中试研究

采用铁炭-混凝沉淀-水解酸化-生物接触氧化工艺对强酸性染料废水进行中试处理研究。在铁炭微电解单元主要考察了铁炭比、HRT和曝气量大小对处理效果的影响;在水解酸化单元主要考察了进水pH和HRT对处理效果的影响。通过铁炭微电解和水解酸化,在大幅改善废水的可生化性的同时,还可以有效去除废水的色度、削减有机负荷,以保证后续的生物接触氧化工艺的高效稳定运行。在生物接触氧化单元主要考察了进水浓度、HRT对处理效果的影响。经过组合工艺的处理,最终的出水COD〈75 mg/L,出水色度〈40倍。     

优选粉煤灰制备人工合成沸石及去除氨氮研究

7种粉煤灰样品的物理化学性质,如元素组成、结晶相组成、比表面积、灼失量、阳离子交换容量和pH得到表征。采用熔融法提取硅铝效率作为粉煤灰原料优选的依据,并通过L9（34）正交实验研究氢氧化钠投加量、熔融温度、氢氧化钠提取液浓度和体积对于硅铝提取效果的影响。结果表明,湿式除尘技术收集的低品位粉煤灰比电除尘技术所收集粉煤灰更...     

遥感震害快速定量评估方法及其在玉树地震中的应用

在伽师地震、汶川地震遥感定量化灾害评估基础上,提出了基于少量现场调查样本进行遥感解译震害与地面实际震害定量评估的方法,以玉树地震为例,建立了遥感解译震害与现场调查结果的定量关系,并进一步得到了玉树县城结古镇街区的等效震害指数和结古镇综合震害指数,结果显示遥感震害快速定量评估结果与实际调查结果一致.该模型可应用于建筑物结构类型分布与玉树县结古镇相似的城镇遥感震害评估工作中.     

一种采用可控复合技术的新型升温炉

在普通电加热炉的基础上,通过配备液化燃烧器加热装置,开发了一种可同时实施自动控制电加热和燃气加热复合升温的新型装配式试验炉。试验测试表明,该新型复合式升温方法能够很好地模拟ISO-834标准升(降)温曲线,同时具有电炉安全可靠、测控精度高、操作简便、无污染,以及液化气火焰升温快、容易控制并可真实模拟火灾的优点,因而具有良好的试验效果和经济效果,是一种实用的结构抗火试验设施。     

Antioxidant and metabolism responses to polyphenol stress in cyanobacterium Microcystis aeruginosa

Three common polyphenol compounds Gallic Acid (GA), Pyrogallic Acid (PA) and Catechol (CA) are known to have allelochemical-exhibiting inhibitory effects on the growth of the cyanobacterium Microcystis aeruginosa (M. aeruginosa). Metabolism and antioxidant responses in M. aeruginosa were investigated to elucidate the mechanism by which the three polyphenols inhibit algal growth. The inhibition effects of polyphenols were in the order of CA > PA > GA. The GA and CA exposures increased protein contents, superoxide dismutase (SOD) activity, catalase (CAT) activity and soluble sugar, especially for exposure to GA of 25 mg L^?1. Soluble sugar content increased significantly especially when exposed to CA for 72 h. When exposed to PA, protein content, and SOD and CAT activities initially increased but over longer treatment time the activities decreased, in contrast to sugar content. Our results suggest that PA exposure for longer periods of time may inhibit catabolism action, while CA exposure could induce more oxide stress than GA or PA. The overall study showed that polyphenol-induced oxidative damage might be responsible for polyphenol inhibition on M. aeruginosa growth. The increases in cellular antioxidant enzymes and soluble sugar may have been to counteract the oxidative stress.     

土壤颗粒级配对镉吸附-解吸规律的影响

利用甘肃金川某地土壤通过批实验进行等温吸附和动力学解吸实验,研究不同颗粒级配的中砂对镉的吸附、解吸特征,并采用Freundlich和一级动力学方程对其吸附解吸方程进行拟合。结果表明,(1)Freundlich和一级动力学方程对该土壤吸附、解吸镉的实验适用;(2)等温吸附实验中4组不同颗粒级配的中砂对镉的吸附性很强,最大平衡吸附量依次为260.667、286.107、299.362和292.232 mg/kg,吸附性能与颗粒级配中的细粒土相对含量大小成正比;(3)4组土壤对镉的解吸在初期2 h内解吸速率均较快,在3 h左右达到吸附-解吸平衡。平衡后4组土样Ⅰ、Ⅱ、Ⅲ和Ⅳ的最大解吸量依次为0.752、0.561、0.44和0.54 mg/kg,解吸速率和平衡时最大解吸量均与颗粒级配中细颗粒相对含量密切相关。     

新型柱状核桃壳活性炭脱硫动力学

采用以农业废弃物核桃壳为原料,天然软锰矿为添加剂共混制成的新型柱状活性炭进行了不同水蒸气含量下的烟气脱硫实验,利用Bangham和Elovich 2种模型对实验结果进行模拟与比较。实验结果表明,随着水蒸气含量的增加,穿透硫容和时间逐渐增加,并在水蒸气含量为10%时达到最大点,此时硫容为243.0 mg/g。模拟结果表明,2种模型均可以较好地模拟烟气脱硫实验结果,其中Elovich模型具有更高的拟合相关度和准确性。在对Elovich模型加以改进以包含水蒸气影响后,可以更好地描述烟气在不同水蒸气含量下的新型柱状活性炭脱硫情况。