聚丙烯酰胺对活性污泥特性的影响研究

高分子混凝剂PAM投加是强化污泥造粒的有效方法,但PAM的投加对活性污泥中微生物群落以及对其生化降解性能的影响尚缺乏系统性研究。为此,通过实验室小型实验,在SBR中连续投加PAM,运用FISH等微生物检测技术,研究了PAM对活性污泥的影响。在PAM投量为3 mg/L的条件下,反应器中活性污泥的生长过程与对照反应器没有根本性差别,且PAM投加后MLSS浓度和单位重量污泥的生物量均有一定增大,污泥的沉降性能也得到改善。FISH检测的结果表明,与对照反应器相比,总细菌、亚硝化菌、硝化菌的个数分别由9.1×105、1.8×105和1.1×105CFU/mL增长到1.0×106、2.0×105和1.2×105CFU/mL,说明PAM没有对各种菌落的生长产生不利影响。连续运行80 d的结果也表明,投加PAM的反应器中COD和氨氮的去除均有所改善。     

紊动特性对污染物降解的影响研究

采用潜水泵作为紊动诱发装置,利用PIV测量了流场,研究了不同流量下紊动对污染物降解的影响规律。结果表明,紊动对污染物的降解有明显的影响,流量越大,紊动强度越大,污染物的降解率越高。对紊动强度与有无紊动水箱COD、NH4^＋-N、TN和TP降解增加量的变化曲线进行指数函数拟合,拟合结果良好,可以认为紊动对污染物降解的影响可以描述为“一级反应”理论。     

容积负荷对厌氧氨氧化反应器运行影响的研究

采用1套有效容积为3 L的厌氧复合床作为厌氧氨氧化反应器,用提高进水基质浓度和缩短反应器水力停留时间2种方式提高反应器的容积负荷,进而研究反应器最佳的进水浓度和水力停留时间。结果表明,在HRT为24 h的条件下,反应器最佳进水浓度NH4+-N与NO2--N在110 mg/L左右;通过调节HRT发现,当HRT大于8 h时,NH4+-N与NO2--N的去除率都在80%以上。     

Effect of ozone on growth of mosses on disturbed forest soil

Mixed forest floor organic matter and upper mineral soil from a 1580 m elevation conifer-hardwood stand in the Pisgah National Forest, NC, was placed in 4-cm diameter x 21-cm deep tubes and exposed to 0.00, 0.08, 0.16, 0.24 or 0.32 microl O3/liter air (ppm). Twelve tubes in each of three replications/treatment were fumigated in continuously-stirred tank reactors in a greenhouse for 6 h/day on 4 consecutive days/week. Soil was watered 3 days/week with deionized water amended with ions and adjusted to pH 4.3 with H2SO4 + HNO3 (70 meq SO4(2-): 30 meq NO3(-)). After 10 weeks the amount of soil surface covered by moss (predominantly Ditrichum pusillum, but also D. lineare, and Pohlia nutans) was estimated visually and assigned a rating on a scale of: 1 = 0-25%; 2 = 26-50%; 3 = 51-75%; 4 = 76-100%. Linear regression analysis revealed a significant (p < 0.001) negative relationship between coverage ratings and O3 concentration. Surface coverage in tubes exposed to 0.32 or 0.24 ppm was about half of that for 0.00 ppm (mean ratings of 1.1, 1.4 and 2.6, respectively). Coverage differences appeared to be due in part to O3 suppression of plant numbers. Linear regression analysis also revealed a significant (p < 0.001) negative relationship between heights of D. pusillum plants (measured after 12 weeks treatment) and O3 concentration.     

五氯苯酚在厌氧颗粒污泥中的吸附研究

在血清瓶中进行的分批实验中,研究了UASB和EGSB反应器厌氧颗粒污泥对五氯苯酚(PCP)的吸附、解吸规律.结果表明,吸附和解吸在接触PCP 2.5 h内达到平衡,吸附和解吸过程都符合Freundich等温方程,PCP的吸附机制为恒定的分配吸附.来自UASB反应器中活的颗粒污泥吸附能力大于灭活的颗粒污泥,Freundich等温方程吸附常数K值分别为0.557 0和0.037 9.UASB反应器颗粒污泥对PCP的吸附能力大于EGSB反应器颗粒污泥,Freundich等温方程吸附常数K值分别为0.557和0.263.     

Study on the cytotoxicity of microcystin-LR on cultured cells

The toxicity of purified blue-green algal toxin, microcystin-LR, on permanent cell lines KB, NIH/3T3, H-4-II-E, HeLa, Vero, Hep G2, Caco-2 and HL-60 was studied. Assessment of cell viability using colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays indicated that purified microcystin-LR induced toxic effect on KB and H-4-II-E cell lines after 96 h incubation at toxin concentrations greater than 18.75 microg/ml. KB cell line was selected for further study when reproducibility, consistency and sensitivity were considered. Significant amounts of lactate dehydrogenase (LDH) were released from KB cells when incubation durations were 72 and 96 h with toxin concentrations of 18.75 microg/ml and higher. Although previous studies suggested that microcystin-LR had no cytotoxic effect on permanent cell lines, LDH release assay performed on KB cells indicated that exposure to microcystin-LR could result in damage to the cell membrane.     

铜对活性污泥微生物活性影响研究

通过人工投加铜离子对驯化污泥的破坏性实验,研究了各浓度铜离子对活性污泥氨氮、COD降解的影响及其TTC-脱氢酶活性、氧摄取速率(SOUR)、氨摄取速率(AUR)的影响。结果显示,0~5 mg/L的铜离子对处理系统有机物的去除率影响不大。铜离子浓度与活性污泥的TTC-脱氢酶活性、SOUR以及AUR之间呈现良好的相关性;低浓度的铜离子对TTC-脱氢酶活性和SOUR均有一定的促进作用,而对AUR则会产生一定的抑制作用。当铜离子浓度达到5 mg/L时,其对SOUR、TTC-脱氢酶活性以及AUR的抑制率均超过50%。在此情况下,采用TTC-脱氢酶活性、SOUR以及AUR等指标,能快速有效地表征铜离子对活性污泥微生物的毒害作用。     

基于GT-Power柴油机颗粒捕集器捕集性能的仿真研究

利用GT-Power软件建立了柴油机颗粒捕集器(DPF)仿真模型,进行了仿真计算。研究了颗粒捕集器本身结构参数对其捕集效率与压降的影响。结果表明,影响颗粒捕集器捕集效率的主要参数有通道密度(CPSI)、过滤体孔隙率、过滤体微孔直径以及过滤壁厚度;影响颗粒物压降的主要参数有通道密度、过滤体渗透率、过滤体孔隙率以及过滤壁厚度。     

纳米材料对膜生物反应器影响的试验研究

通过向一体式膜生物反应器中投加纳米材料来改变料液性质,预防膜污染和提高膜生物反应器对污染物的去除效率,并利用扫描电镜分析中空纤维膜的表观结构的变化情况,通过红外光谱分析活性污泥性质的变化,以探讨防治膜污染的机理。试验结果表明,纳米材料的投加对COD和NH₃-N的去除无明显影响,提高了TP的去除率,TP去除率达70%。而且投加纳米材料可改变活性污泥的性质和生物膜的表观结构,减缓膜污染。     

Studies on the sorption behaviors of nitrobenzene on marine sediments

The sorption behaviors of nitrobenzene on marine sediments were systematically investigated in this study. The nitrobenzene sorption on both HCl-treated and untreated sediments accorded well with the linear sorption isotherm. It occurred primarily through partition function of organic carbon of sediments. In comparison, the sorption behavior of nitrobenzene on H2O2-treated sediments was nonlinear and conformed to Langmuir isotherm. Sorption of nitrobenzene on H2O2-treated sediment was mainly through surface function of sediment minerals such as clays. With the increase of ionic strength (salinity), solubility of nitrobenzene in solution would decrease. At the same time, the release of dissolvable part of organic carbon into water solution would also decrease. As a result, partition coefficient and saturate adsorption amount of nitrobenzene on marine sediments increased with increasing salinity of seawater. Contrary to the influence of salinity, partition coefficient and saturate adsorption amount of nitrobenzene decreased with increasing temperature.     

回流比对缺氧/好氧生活污水处理装置处理效果的影响

在缺氧／好氧工艺的不同回流比条件下,对处理效果特别是脱氮效果进行了研究。结果表明,混合液和污泥合并回流,当回流比从R=4到R=7时,均能获得良好的脱氮效果,TN去除率达到75．4％以上,出水TN〈10mg／L。而回流比的变化对BOD的去除效果影响较小。当BOD污泥负荷从0．096kg／（kg&#183;d）降低到0．063ks／（kg&#183;d）时,对TN和BOD的去除率影响都很小。     

基于DEA模型的区域削减指标分配研究

运用数据包络分析(DEA)方法,建立了区域削减指标分配模型,综合分析了2005年全国31个省、市、自治区的主要污染物COD和SO2排放绩效以及水资源、能源的利用效率.分析表明,我国COD、SO2的排放效率、水资源和能源的利用效率比较低,节水节能减排的潜力很大.根据效率原则,得到了全国各地区节能节水减排的削减指标分配表.     

Effect of phosphate on the adsorption of Cu and Cd on natural hematite

Interactions between anions and cations are important to understand the chemical processes of pollutants in environment. In this study, batch experiments were carried out to investigate the simultaneous adsorption of Cu and Cd on hematite as affected by phosphate. Phosphate pretreatment suppressed the maximum adsorption of Cu and Cd on hematite and moved the adsorption pH edges to a higher pH range. Phosphate application time had a marked impact on Cu and Cd adsorption and longer contact time resulted in more reduction of Cu and Cd adsorption. Results of back-titration, Fourier transform infrared (FTIR) spectroscopy study and ionic strength effect on the adsorption revealed that Cu and Cd were adsorbed on hematite mainly through the inner-sphere complex formation mechanism and phosphate treatment reduced the inner-sphere adsorption sites, thus decreasing Cu and Cd adsorption on hematite.     

Effects of cadmium on sediment processing on members of the Capitella species-complex

The effect of cadmium on sediment processing by laboratory-cultured specimens of Capitella sp I and Capitella sp B was investigated. Specimens were exposed to 0, 60, 90 and 140 microg Cd g(-1) dry weight sediment for a 10 day period (two census days) to observe effects of cadmium on their feeding activity. Under unstressed conditions, Capitella sp I specimens were larger, had higher biomass and produced more fecal pellets than Capitella sp B. Cadmium concentrations had no effect on pellet production and body mass of the studied populations. However, cadmium exposure time significantly affected Capitella sp B pellet production and body mass of both populations following different trends: after 10 days of exposure, the average processed sediment per unit worm mass decreased in Capitella sp I but increased in Capitella sp B. The latter population did not reduce its feeding activity in the presence of cadmium maybe related to the fact that it is derived from a highly polluted environment. This study has shown an unimpaired response of Capitella sp I and Capitella sp B to cadmium in their sediment processing activity, which indicates the potential importance of this species complex in the trophic transfer of metals from sediments to other marine organisms.     

Effects of humic substances on photodegradation of bensulfuron-methyl on dry soil surfaces

The photodegradation of the herbicide bensulfuron-methyl on dry soil surfaces in the presence and absence of humic substances was investigated under Xe lamp irradiation. A rapid rate of disappearance occurs in the humus-removed soil. The presence of humic acid (HA) and fulvic acid (FA) reduces degradation rates and has a quenching effect on the photodecomposition of bensulfuron-methyl. The quenching effect increases with increasing HA and FA concentration in soil. HA has a slightly greater ability to quenching the photolysis compared to FA. In addition, co-effects of HA and FA on quenching the photolysis are stronger than single effects of HA or FA.     

香菇菌渣对土壤微生态的影响

为研究香菇菌渣添加对土壤质量改善的效果和机制,在土壤中添加质量分数为0(对照)、1.5％、3.0％、4.5％的香菇菌渣进行培养处理,并定期检测土壤中各类微生物的数量与某些酶活性.结果表明:添加香菇菌渣对土壤微生物数量和酶活性都有不同程度的提高作用,其中真菌数量、放线菌数量、几丁质酶活性和脱氢酶活性均随添加量的增加而增大,说明香菇菌渣能够增加土壤中微生物群落的规模,从根本上有利于土壤质量的改善,同时还增强了土壤潜在的抑病能力;4.5％处理的平均真菌数量、放线菌数量、几丁质酶活性、脱氢酶活性分别为对照的1 399.00％、2 773.33％、1 309.36％、2 512.29％.     

基于关联模型的二恶英在线检测研究

为实现二恶英快速检测,指导废物焚烧炉二恶英减排,通过检测生活垃圾焚烧炉烟气中氯苯和二恶英浓度,研究了三氯苯、四氯苯和二恶英之间的关联关系,并利用实验室自行研制的飞行时间质谱仪对烟气样品的三氯苯进行在线检测。结果表明,三氯苯与二恶英毒性当量(I-TEQ)之间存在良好关联性,相关系数(R2)可达到0.89。仪器检测信号强度与三氯苯浓度之间具有良好的线性关系,根据在线检测烟气样品中三氯苯的信号可得到三氯苯浓度,并根据关联模型计算得到二恶英毒性当量值I-TEQ,实现了对烟气样品中二恶英的快速间接测量。     

不同稳定剂对污泥蛋白发泡特性的影响研究

污泥含有蛋白质,经过高温水解可产生水解蛋白液(简称污泥蛋白),该蛋白具有发泡特性,经通风搅拌可产生泡沫;由于污泥蛋白所产生的泡沫具有不稳定、易破裂的特点,因此,设计了不同稳定剂对污泥蛋白发泡特性的影响研究实验,解决污泥蛋白所产生泡沫的稳定性问题。结果表明,在测定污泥蛋白的基本发泡特性实验中,10 mL污泥蛋白稀释10倍时,初始泡沫量较大,达到2 153 mL,但泡沫半衰期相对较短,时间为27 min;在10 mL污泥蛋白中分别加入0.2 g十六烷基三甲基溴化氨(CTAB)、羧甲基纤维素钠(CMC)、GP-1,并用水稀释10倍,制成泡沫后的初始泡沫量分别为1 380、1 400和1 248 mL,相对降低了773、753和905 mL;泡沫半衰期分别为31、76和509 min,相对提高了4、49和482 min,尤其是GP-1作为稳定剂时,泡沫的半衰期与不加稳定剂时相比提高了15倍;在10 mL污泥蛋白中加入0.2 g十六烷基三甲基溴化氨与0.2 g GP-1的复配稳定剂,用水稀释10倍,制成泡沫后的初始泡沫量为1 525 mL,相对降低了628 mL;泡沫半衰期为95 min,相对提高了68 min。因此,GP-1是污泥蛋白最好的泡沫稳定剂。     

重碳酸盐碱度对电吸附设备除盐性能影响的研究

为了系统地考察重碳酸盐碱度对电吸附设备除盐性能的影响,利用小型电吸附模块对含有不同重碳酸盐碱度的原水水质进行处理.实验结果表明,随着其含量从170 mg/L增加到400 mg/L,电吸附设备的除盐率明显下降.通过对起始工作电流降低这一变化作理论分析,认为重碳酸盐碱度在电吸附模块内部积存结垢是影响电吸附设备除盐性能的重要原因,并通过实验证实其与钙离子共同作用导致了结垢.