预氧化-混凝沉淀法快速去除水中砷研究

探讨预氧化-混凝沉淀法快速去除水中砷污染物的可行性,结果表明,在氧化时间均为10min条件下,KMnO4投加量为0．5mg／L时,聚氯化铝和聚合硫酸铁投加量分别为8mg／L和16mg／L时,可将原水中《生活饮用水卫生标准》（GB5749—2006）限值5倍浓度的砷降低到限值以下,去除率约90％。NaClO投加量（以有效氯计）为0．8mg／L时,聚氯化铝和投加量分别为8mg／L和20mg／L时,可将原水中《生活饮用水卫生标准》（GB5749—2006）限值5倍浓度的砷降低到限值以下,去除率约85％。以聚氯化铝为混凝剂的除砷效果优于聚合硫酸铁,以KMnO4氧化剂的除砷效果略优于NaClO。     

葡萄糖共基质下硝基酚产甲烷毒性研究

在中温（35℃）厌氧间歇试验条件下，以葡萄糖为共基质，通过测定累计产甲烷量，研究了3-硝基酚（3-NP）、2，4-二硝基酚（2，4-DNP）和2，6-二硝基酚（2，6-DNP）的厌氧毒性，并利用相对活性确定了反应时间为24、48、72和96h时3种硝基酚的50％相对抑制浓度。结果表明：当33N-P浓度≤40mg／L时，对产甲烷菌没有产生抑制，反而有促进作用；当浓度为80-160mg／L时产生轻度抑制；当浓度≥320mg／L时产生重度抑制。当32，4-DNP浓度≤10mg／L时，对产甲烷菌不产生抑制；当浓度≥20mg／L时产生重度抑制。当32，6-DNP浓度≤20mg／L时，对产甲烷菌不产生抑制；当浓度为40mg／L时产生轻度抑制；当浓度≥80mg／L时产生重度抑制。根据50％相对抑制浓度判断，3种硝基酚对产甲烷菌活性的抑制大小顺序为2，4-DNP〉2，6-DNP〉3-NP。     

重铬酸钾对泥鳅鳍细胞系的毒理学研究

为探究重铬酸钾的毒性机制,建立适合监测铬污染的体外检测系统,以体外培养的泥鳅Misgurnus anguillicaudatus鳍细胞系(DIMF)为试验材料,研究了重铬酸钾的毒性效应。结果表明:通过噻唑蓝(MTT)比色法测定重铬酸钾染毒后细胞的24 h半致死浓度为(25.3±1.2)μmol/L;暴露在浓度为0~30μmol/L的重铬酸钾中,细胞超氧化物歧化酶(SOD)活性随着染毒浓度的增加而增大;谷胱甘肽超氧化物酶(GSH-Px)在重铬酸钾浓度为0~20μmol/L时活性升高,当染毒浓度为30 mol/L时,活力开始下降;谷胱甘肽S-转移酶(GST)活性则随重铬酸钾浓度的升高而降低;微核试验显示,DIMF微核率随染毒浓度的增加呈先升高后降低的趋势,其中最大微核率为0.733%;实时定量PCR结果显示,对照组的金属硫蛋白(MT)基因表达量很低,经重铬酸钾诱导后MT基因表达量显著升高(P<0.01)。研究表明,重铬酸钾可对细胞的酶系统和遗传物质造成一定的损伤。     

姜黄素抑制膀胱癌T24细胞增殖及Hsp90α的表达

目的探讨姜黄素对膀胱癌T24细胞增殖以及热休克蛋白90α(Hsp90α)表达的影响。方法培养T24细胞株,分别用不同浓度姜黄素(0,5,10,15,20μmol/L)处理细胞24小时和20μmol/L姜黄素分别处理细胞不同时间(0,6,12,24,48小时),采用四唑盐(MTT)比色法,检测T24细胞的生长抑制率,采用逆转录聚合酶链式反应(RT-PCR),检测Hsp90α基因mRNA的表达,以蛋白免疫印迹法(Western blotting),检测Hsp90α蛋白质的表达。结果姜黄素处理后的T24细胞代谢MTT能力降低,细胞生长抑制率明显增加;细胞Hsp90α基因mRNA和蛋白质的表达均下调,并且这些效应呈浓度和时间依赖性(P<0.05)。结论姜黄素可能通过调控Hsp90α的表达而抑制T24细胞的增殖。     

三氧化二砷对耐伊马替尼K562细胞株增殖、凋亡和bcr/abl基因表达的影响

目的观察三氧化二砷（ATO）对耐伊马替尼K562（K562G）细胞增殖、凋亡和bcr/abl融合基因（bcr/abl基因）表达的影响。方法用不同浓度的伊马替尼（STI571）（0.25、2.50、10.00μmol.L-1）、ATO（1.0、5.0、10.0μmol.L-1）以及两者联合作用于K562G细胞,用MTT比色法测定药物对K562G细胞生长抑制率的影响、PI单染色法流式细胞仪检测K562G细胞凋亡率、荧光定量PCR检测K562G细胞bcr/abl基因的表达水平。结果 STI571作用于K562G细胞的细胞生长抑制率、细胞凋亡率和bcr/abl基因水平与对照组比较差异无统计学意义（P〉0.05）。与对照组比较,ATO作用于K562G细胞的细胞生长抑制率和细胞凋亡率明显增高（P〈0.05）,bcr/abl基因表达水平明显降低（P〈0.05）;细胞抑制率呈剂量依赖性,细胞凋亡率以中浓度5.0μmol.L-1时最明显。ATO＋STI571联合用药作用于K562G细胞的细胞生长抑制率和细胞凋亡率与对照组以及单用ATO组比较差异有统计学意义（均P〈0.05）,细胞抑制率呈剂量依赖性,细胞凋亡率以中浓度ATO（5.0μmol.L-1）＋STI571（2.50μmol.L-1）时最明显,bcr/abl基因水平降低比单用ATO组更明显（P〈0.05）。结论 K562G对≤10.0μmol.L-1浓度的STI571耐药;ATO能明显抑制K562G细胞生长和诱导K562G细胞凋亡,使K562G细胞bcr/abl基因表达水平降低;ATO与STI571联合用药作用于K562G细胞时,细胞抑制率和细胞凋亡率比单用ATO效果好,bcr/abl基因表达水平降低更明显,两者有协同作用。     

重铬酸钾对泥鳅鳍细胞系的毒理学研究

为探究重铬酸钾的毒性机制,建立适合监测铬污染的体外检测系统,以体外培养的泥鳅Misgurnus anguillicaudatus鳍细胞系(DIMF)为试验材料,研究了重铬酸钾的毒性效应。结果表明:通过噻唑蓝(MTT)比色法测定重铬酸钾染毒后细胞的24 h半致死浓度为(25.3±1.2)μmol/L;暴露在浓度为0³0μmol/L的重铬酸钾中,细胞超氧化物歧化酶(SOD)活性随着染毒浓度的增加而增大;谷胱甘肽超氧化物酶(GSH-Px)在重铬酸钾浓度为030μmol/L的重铬酸钾中,细胞超氧化物歧化酶(SOD)活性随着染毒浓度的增加而增大;谷胱甘肽超氧化物酶(GSH-Px)在重铬酸钾浓度为0²0μmol/L时活性升高,当染毒浓度为30 mol/L时,活力开始下降;谷胱甘肽S-转移酶(GST)活性则随重铬酸钾浓度的升高而降低;微核试验显示,DIMF微核率随染毒浓度的增加呈先升高后降低的趋势,其中最大微核率为0.733%;实时定量PCR结果显示,对照组的金属硫蛋白(MT)基因表达量很低,经重铬酸钾诱导后MT基因表达量显著升高(P<0.01)。研究表明,重铬酸钾可对细胞的酶系统和遗传物质造成一定的损伤。     

硝酸盐氮、总氮的测定 气相分子吸收光谱法

HJ／T 198—2005规定了地表水和污水中硝酸盐氮的气相分子吸收测定方法，适用于地表水、地下水、海水、饮用水、生活污水及工业污水中硝酸盐氮的测定，检出限为0．006mg／L，测定上限为10mg／L。HJ／T 199—2005规定了总氮的气相分子吸收测定方法，适用于地表水、水库、湖泊、江河水中总氮的测定，检出限为0．050mg／L，测定下限为0．200mg／L，测定上限为100mg／L。本标准为首次制订，于2006年1月1日实施。     

双酚A冲击对活性污泥毒性的影响研究

在SBR系统中,控制进水COD浓度稳定在300 mg/L左右,分别以初始浓度为20和40 mg/L的双酚A(BPA)对其进行冲击试验,考察污泥毒性的变化规律,同时分析水相中COD以及水、泥相中BPA含量的变化规律。结果表明,BPA冲击过程会导致污泥有机毒性升高,冲击初期污泥毒性抑制率在40%~60%之间波动,后期稳定在38%~43%之间,且污泥有机毒性的上升幅度与BPA初始冲击浓度呈正相关关系。     

UASB/水解酸化/曝气生物滤池处理高浓度聚酯废水

介绍了UASB／水解酸化／曝气生物滤池工艺在聚酯废水处理中的应用，并进行了工艺参数的选择和运行效果的分析。结果证明，当进水COD、BOD5浓度分别为（1—1．2）×10^4mg／L和3450—4200mg／L时，处理出水COD≤150mg／L，BOD5≤30mg／L，能够达到《污水综合排放标准》（GB8978--1996）的二级排放标准。     

水源水受挥发酚污染应急处理试验研究

本文在常规工艺基础上,研究利用投加粉末活性炭（Powdered Activated Carbon,简称PAC）技术来处理原水突发的挥发酚类污染。试验表明,苯酚浓度超标30倍左右时,粉末活性炭投加量80mg／L以上,2小时后检测挥发酚均低于0．002mg／L,去除率100％,能达到生活饮用水新国标水质的要求。挥发酚类物质的浓度用QC8000流动注射分析仪进行检测。     

Origin and stormwater runoff of TCP (tricresyl phosphate) isomers

TCP concentration in the Kurose River, Higashi-Hiroshima, increases after rainy days, suggesting that typical contamination originates from non-point sources. Our study was focused on a greenhouse as an important source of TCP isomers. The amounts of TCP released from agricultural plastic films were studied. Field surveys during rainy days were also carried out to clarify the processes which release TCP isomers from the greenhouse with rainfall, and its accumulation and degradation processes in soil. The runoff processes of TCP from greenhouse to ditch and river was also investigated. Concentration of TCP isomers in rainfall drop from a greenhouse were significantly higher than those in rainwater and river water, indicating that agricultural plastic films were the probable source of TCP. The ratio of o-TCP concentration in rainfall drop from greenhouse decreased with time, whereas that of m-TCP increased. These results suggest that more o-TCP was released from plastic film than m-TCP. TCP released from plastic film by rainfall was preferentially adsorbed on the silt-clay fraction of the soil. The m-TCP isomer concentration in soil around the greenhouse increased if cumulative precipitation for 3 consecutive days before sampling was less than 20 mm, but decreased if it was more than 20 mm. TCP concentration in the soil was highest in the surface (0–1 cm) and decreased below the surface. The significant decrease with depth is probably affected by adsorption and biodegradation. TCP concentrations in surface soil and water decreased along the flow of surface water from greenhouse to ditch. It is probable that TCP released from the greenhouse was transported to the ditch with adsorption on top soil.     

Removal of 2,4,6-trichlorophenol and natural organic matter from water supplies using PAC in floc-blanket reactors

The objective of this study was to evaluate the addition of powdered activated carbon (PAC) to upflow floc-blanket reactors for the adsorption of natural and synthetic organic chemicals. A 15.5-1. bench-scale floc-blanket reactor was operated with PAC addition for the adsorption of 2,4,6-trichlorophenol (TCP) and natural organic matter from one groundwater and two surface waters under laboratory and field conditions, respectively. Influent TCP concentrations ranged from 21 to 415 μg/l. The PAC doses ranged from 2 to 12 mg/l. While the hydraulic residence time in the floc-blanket reactor varied from 15 to 30 min, the carbon residence time ranged from 9 to 34 h. This is due to the high solids concentration in the floc blanket, which ranged from 1200 to 8700 mg/l. Comparison between the extent of TCP adsorption through the floc-blanket reactor and the equilibrium adsorption isotherms of TCP on PAC showed that the maximum adsorption capacity of PAC for TCP was utilized in the reactor. However, this study showed that the maximum adsorptive capacity of the carbon in a continuous process is dependent on the influent adsorbate concentration. This was in agreement with isotherm studies conducted with varying initial TCP concentration. The maximum PAC adsorption capacity for natural organic matter was also achieved in the floc-blanket reactor.     

Toxicity of chlorpyrifos and TCP alone and in combination to Daphnia carinata: the influence of microbial degradation in natural water

The acute toxicity of chlorpyrifos and its principal metabolite 3,5,6-trichloropyridinol (TCP) alone and in combination to a cladoceran, Daphnia carinata, was studied in both cladoceran culture medium and natural water collected from a local suburban stream. TCP was found to be more toxic than its parent chemical chlorpyrifos to Daphnia survival in cladoceran culture medium. However, TCP in natural water was not toxic to D. carinata up to 2 microgL(-1). The LC(50) values for chlorpyrifos, TCP and chlorpyrifos+TCP were 0.24, 0.20 and 0.08 microgL(-1), respectively, in cladoceran culture medium. Although the parent chemicals and their degradation products co-exist in natural waters, the existing guidelines for water quality are based on individual chemicals. The results of this investigation suggest that chlorpyrifos and TCP can interact synergistically, additively or antagonistically, resulting in an increase or decrease in the overall toxicity of the mixture compared to individual compounds. The indigenous microorganisms in natural water could play a significant role in degradation of these compounds thereby influencing their toxicity in receiving waters. This study clearly suggests that the joint action of pesticides and their degradation products should be considered in the development of water quality guidelines. To our knowledge, this is the first study on the interactive effect of chlorpyrifos and TCP to a cladoceran and suggests that these two compounds are non-toxic when present together at concentrations up to 0.12 microgL(-1). However, these compounds together act additively at and above 0.5 microgL(-1) to fresh water invertebrates and therefore pollution with these compounds may adversely affect natural ecosystems.     

Adsorption of 2,4,6-trichlorophenol by multi-walled carbon nanotubes as affected by Cu(II)

Adsorption equilibrium of 2,4,6-trichlorophenol (TCP) on multi-walled carbon nanotubes (MWCNTs) was investigated to explore the possibility of using MWCNTs for concentration, detection and removal of TCP from contaminated water. The adsorption of TCP on MWCNTs at pH 4 was nonlinear, reversible and best fit by a Polanyi-Manes model. Oxidation treatment increased surface area and introduced hydrophilic carboxylic groups to the defect sites of MWCNTs, hence increased the sorption of TCP and Cu(II) individually. Cu(II) suppressed the sorption of TCP on oxidized MWCNTs15A, but had little effect on as-grown MWCNTs15. TCP had no influence on Cu(II) sorption to either. The mechanisms of Cu(II) suppression effect on TCP adsorption are ascribed to the formation of surface complexes of Cu(II), which was verified by X-ray absorption spectroscopy. Cu(II) exerts a cross-linking effect of functional groups on adjacent tubes, creating a more tightly knit bundle and suppressing the condensation of TCP in the pore spaces between the tubes. The large hydration sphere around surface complexes of Cu(II) may also intrude or shield hydrophilic sites, leading to the “crowding out” of TCP around the Cu(II)-complexed sites.     

Treatment of trichlorophenol by catalytic oxidation process

The oxidation of 2,4,6-trichlorophenol (TCP) by ferrous-catalyzed hydrogen peroxide was quantified and modeled in the study. TCP was effectively degraded by hydroxyl radicals that were generated by Fe(II)/H(2)O(2) in the oxidation process. The oxidation capacity (OC) of the process depends on the concentrations of oxidant (hydrogen peroxide) and oxidative catalyst (ferrous ion). Up to 99.6% of TCP removal can be achieved in the process, provided the doses of Fe(II) and H(2)O(2) are selected correctly. The OC of the process was successfully predicted through a kinetic approach in a two-stage model with some simple and measurable parameters, which makes the model useful for predicting, controlling and optimizing the catalyzed oxidation process in the degradation of TCP.     

Biodegradation of chlorpyrifos and 3, 5, 6‐trichloro‐2‐pyridinol by a novel rhizobial strain Mesorhizobium sp. HN3

A chlorpyrifos (CP) and 3,5,6‐trichloro‐2‐pyridinol (TCP) degrading bacterial strain, Mesorhizobium sp. HN3, was isolated and characterized. Mesorhizobium sp. HN3 degraded CP efficiently up to 400 mg/L initial concentration at wide range of temperatures (30–40°C) and pH (6.0–8.0). However, optimal degradation of CP was achieved at 37°C and neutral pH (7.0) at an initial inoculum density 2 × 10⁷ colony forming unit/mL of culture medium. Kinetic parameters for CP degradation by Mesorhizobium sp. HN3 were estimated at different initial concentrations. Cultures exhibited significant variation (P ≤ 0.05) in the specific growth rate (μ), cell mass formation rate (Q_X) and the substrate uptake rate (Q_S) during degradation of CP. The values of kinetic parameters increased up to 100 mg/L CP and decreased at higher concentration. Investigation of degradation metabolites indicated that CP is converted to diethylthiophosphate and TCP that leads to the formation of 3,5,6‐trichloro‐2‐methoxypyridine.     

Enhancement of unconfined compressive strength of sand test pieces cemented with calcium phosphate compound by addition of various powders

To improve the unconfined compressive strength (UCS) of a novel chemical grout composed of a calcium phosphate compound (CPC-Chem), we performed UCS tests and scanning electron microscopy (SEM) observations on sand test pieces cemented with CPC-Chem and four kinds of powders (tricalcium phosphate, TCP; magnesium phosphate, MgP; calcium carbonate, CC and magnesium carbonate, MgC) as seed crystals. The UCS of the CPC-Chem test pieces cemented with TCP and CC was significantly greater than that of the test pieces with no added powders. The UCS of the test pieces with TCP and CC additives exceeded the targeted value of 100 kPa and increased to a maximum of 261.4 kPa and 209.7 kPa for the test pieces with TCP and CC additives, respectively. Furthermore, the UCS of test pieces with 1 wt% or 5 wt% TCP and 1 wt% CC additives was maintained at a level exceeding 200 kPa for 168 days. SEM observations revealed net-like and three-dimensional structures in segments of test pieces cemented with 1 wt% or 5 wt% TCP and 1 wt% CC in CPC-Chem, which could have been the reason of the long-term stability of UCS (over 200 kPa for 168 days) observed in this study. These results suggest that the addition of TCP and CC significantly enhances the ground improvement afforded by CPC-Chem.     

Production of Shiga-like toxins in viable but nonculturable Escherichia coli O157:H7

Escherichia coli O157:H7, a causative agent of hemolytic uremic syndrome, can enter into a viable but nonculturable (VBNC) state when under stress. To date, it is unknown whether VBNC cells produce Shiga-like toxins (Stx). To address this question, we confirmed the expression of the stx1 and stx2 genes and the production of Stx in VBNC E. coli O157:H7 cells. To quantitatively assess the production of Stx in VBNC cells, we developed a Vero-cell microplate cytotoxicity assay based on the correspondence of the cytotoxicity of VBNC cells on Vero cells to the number of inoculated VBNC cells. Using this method, we found that all VBNC cells induced by river water, PBS buffer, deionized water, or chloraminated water retained the ability to produce Stx, and that they had differing levels of Stx. Both aged (19-month-old) VBNC cells induced by river water and fresh VBNC cells induced by chloraminated water showed very low half maximal inhibitory concentration (IC₅₀; 6.6 × 10⁴ and 7.1 × 10⁴ respectively), corresponding to higher levels of toxins produced than VBNC cells induced by deionized water and PBS buffer. VBNC cells originating from different isolates may vary in Stx production, and the VBNC cells from bovine isolates produced higher levels of Stx than those from clinical isolates. These results demonstrate a potential health risk of VBNC E. coli O157:H7 in environmental water and the importance of monitoring VBNC E. coli O157:H7.     

智能家居网关设计

该文主要论述了以太网技术在智能家居系统中的应用与实现,完成了智能家居网关的设计。智能家居网关以32位高性能单片机STM32为核心控制器,通过以太网控制器支持TCP、UDP和DHCP PPPOE协议。智能家居网关通过以太网接收各智能节点所采集的环境数据(温度、湿度、CO浓度等)并对数据进行处理,同时用液晶屏显示各个节点的信息。另外智能网关可按需设置不同的报警阈值,当设定的报警阈值小于节点的实际测量值时,可对危险信息进行报警同时通过以太网向节点发送相应的控制命令。测试结果表明该网关能够有效实现对各个智能节点信息的有效管理和处理。