Preliminary environmental impact assessment of PFOS waste treatment in a lab-scale batch subcritical water decomposition operation

Life cycle assessment (LCA) was carried out by SimaPro 7.3 to study the environmental impact of a lab-scale batch subcritical water decomposition operation for a kilogram of Perfluorooctane sulfonic acid (PFOS) waste treatment in this study, a proven process for the decomposition of PFOS pollutants with high concentration. This LCA focuses on not only the main environmental factors from emissions of toxic pollutants, but also the influence from technical characteristics of the iron-induced subcritical water technology including energy and substances consumption during the subcritical water decomposition treatment process. The IMPACT 2002+ environmental model was used to evaluate the 15 midpoint and 4 end-point environmental damages. It was found that the energy consumption to sustain the high temperature (350 °C) and high pressure (23 MPa) in the subcritical water process contributes 99.8 % of the damages. The total negative impact of the SCWD process for 1 kg of PFOS waste treatment to human health, ecological quality, climate change and resources amounts to 1.11 × 10^?3, 8.43 × 10^?5, 9.76 × 10^?4, 9.05 × 10^?4 Pt, respectively. And the improvement of energy efficiency and catalytic effectiveness are two important factors to reduce the environmental impact from the SCWD process for the treatment of PFOS waste.     

利用盐泥制取轻质氧化镁

采用二氧化碳法提取盐泥中的镁,研究了使之转化为轻质氧化镁的影响因素以及主要反应的动力学性质。实验确定的最佳条件为固液比1∶15、二氧化碳通入时间90min、水解温度90℃、水解时间25min,在此条件下,盐泥中镁的总提取率为75%;采用微分法求得氢氧化镁与二氧化碳反应的反应级数和活化能分别为1.7和68.1kJ/mol。     

木粉/壳聚糖接枝丙烯酸-丙烯酰胺吸附树脂对二元重金属离子溶液中Pb^2＋的吸附

采用自制木粉/壳聚糖接枝丙烯酸-丙烯酰胺吸附树脂R1、R2、R3对二元金属离子Cu2＋/Pb2＋和Zn2＋/Pb2＋溶液中的吸附性能进行了较系统考察。Pb2＋离子溶液中存在竞争离子Cu2＋、Zn2＋时,随竞争离子浓度增加,3种吸附树脂R1、R2、R3对Pb2＋的吸附量明显下降,而竞争离子吸附量显著增加。二元溶液中各金属离子浓度相同时,3种树脂对竞争离子Cu2＋、Zn2＋的吸附量大于对Pb2＋的吸附量;各溶液中分别加入NaCl及NaNO3、尿素后,对Pb2＋离子的吸附量下降迅速。随吸附树脂用量增加,竞争离子Cu2＋、Zn2＋的吸附量逐渐减小,Pb2＋的吸附量在吸附树脂用量0.10 g/L（Zn2＋/Pb2＋溶液）或0.15 g/L（Cu2＋/Pb2＋溶液）时出现最大值。溶液pH值对树脂吸附性能有显著影响。3.0     

Occurrence and fate of PPCPs and correlations with water quality parameters in urban riverine waters of the Pearl River Delta, South China

The occurrence and fate of eight PPCPs was studied in river waters from upstream to downstream of the three rivers in the Pearl River Delta, China. The correlations of PPCP levels and water quality parameters were also investigated. The analytes of the highest concentrations were caffeine, acetaminophen, and ciprofloxacin. Carbamazepine and erythromycin-H₂O were detected at the lowest concentrations. The highest concentrations of PPCPs were found in the Shijing River, with 865 ng/L caffeine, 339 ng/L acetaminophen, and 304 ng/L ciprofloxacin. In general, the levels of PPCPs in the Zhujiang River were higher at sites where the metropolitan city Guangzhou is located and decreased from the epicenter along the river. Low levels of PPCPs were generally found in the Beijiang River. Positive correlations were found between PPCP levels, total nitrogen, ammonium nitrogen, and cumulative fluorescence excitation-emission matrix (EEM) volume. Among the four PPCPs evaluated (caffeine, acetaminophen, ciprofloxacin, and sulfamethoxazole), caffeine had the best correlations with the correlation coefficients ranging from 0.62 to 0.98. The prediction of PPCP concentrations at specified locations can be substantially simplified.     

物化-生化组合工艺处理造纸化学品废水的中试研究

针对造纸化学品生产废水具有成分复杂,可生化性差,有机物、NH3-N、Cl-浓度高的特点,采用"初沉池-悬浮生物滤池(A/O)-混凝沉淀池-催化氧化池-硝化滤池"组合工艺对造纸化学品生产废水进行了中试研究,取得很好的处理效果。结果表明,在进水COD为4 832～12 846 mg/L,NH3-N为39～430 mg/L,Cl-为3 200～15 000 mg/L的情况下,处理后出水COD小于500 mg/L,NH3-N小于35 mg/L,主要指标达到污水综合排放标准(GB 8978-1996)三级标准。     

城市生活污水中志贺氏菌ipaH毒力基因的定量PCR检测

基于ipaH毒力基因的实时荧光定量PCR检测,建立适合城市污水中志贺氏菌的定量检测方法。使用从临床分离出的志贺氏菌构建重组质粒作为实时荧光定量PCR的标准品。在ipaH基因模板量2.58×100～2.58×106copy范围内具有良好的线性关系,每100 mL水样中含有2.58×101copy以上的ipaH基因即可被检出。从西安市生活污水分离得到2株野生型志贺氏菌,分析ipaH基因数量和菌体数量的关系,从而确定ipaH基因定量检测志贺氏菌的可行性。该方法灵敏、快速、特异性好,适用于城市生活污水中志贺氏菌的检测。     

The short-term effect of cadmium on low molecular weight organic acid and amino acid exudation from mangrove (Kandelia obovata (S., L.) Yong) roots

The aim of this study was to evaluate short-term concentration and time effects of cadmium on Kandelia obovata (S., L.) Yong root exudation, thereby evaluating and predicting the ecophysiological effects of mangrove to heavy metals at the root level. Mature K. obovata propagules were cultivated in a sandy medium for 3 months, and then six concentrations of Cd (0, 2.5, 5, 10, 20, and 40 mg L^?1) were applied. After exposure time of 24 h and 7 days, respectively, the root exudates of K. obovata were collected and low molecular weight organic acids (LMWOAs) and amino acids of which were analyzed. In addition, we measured glutathione, soluble protein content, and Cd concentration in the plant. We found 10 and 15 types of LMWOAs and amino acids in root exudates of K. obovata with total concentrations ranging from 29.54 to 43.08 mg g^?1 dry weight (DW) roots and from 737.35 to 1,452.46 ng g^?1 DW roots, respectively. Both of them varied in quality and quantity under different Cd treatment strengths and exposure times. Oxalic, acetic, l-malic, tartaric acid, tyrosine, methionine, cysteine, isoleucine, and arginine were dominant. Both LMWOAs and amino acids excreted from K. obovata roots play a key role in Cd toxicity resistance. The responsiveness of amino acids was less than that of LMWOAs. We suggest that the ecological effect of root-excreted free amino acids in the rhizosphere is mainly based on the role of nutrients, supplemented with detoxification to heavy metals.     

紫外光促进盐酸聚苯胺催化H_2O_2氧化处理罗丹明B废水

以苯胺和过硫酸铵为主要原料合成了盐酸聚苯胺（HClPANI）催化剂,并通过FTIR、XRD、SEM和EDS对催化剂进行了表征。研究了在紫外光照下、HClPANI催化H2O2氧化处理罗丹明B染料废水工艺参数,探讨了各种因素对废水脱色效果的影响,并对催化氧化机理进行了初步探讨。结果表明,催化剂HClPANI对催化H2O2氧化处理罗丹明B具有较好的催化活性、稳定性和重复使用性能。UV-H2O2-HClPANI体系产生了明显的协同效应,在pH=3、200 mg/L的罗丹明B废水中,30%H2O2用量为1.2 mL/L、HClPANI用量1 g/L、反应温度25℃、紫外灯功率500 W、光照70 min,罗丹明B脱色率达到了98.2%。     

Influence of tetracycline exposure on the growth of wheat seedlings and the rhizosphere microbial community structure in hydroponic culture

In this study, the effects of tetracycline exposure on wheat growth and the microbial community structure in the rhizosphere were investigated under hydroponic culture conditions. Exposure to various concentrations of tetracycline resulted in significant suppression of the growth of wheat roots and shoots, with minimum doses of 0.8 mg L^?1 and 4 mg L^?1 resulting in inhibition rates of 32% and 15.4%, respectively. Complete inhibition of the growth of these two parts of wheat plants was observed in response to treatment with tetracycline at 20 mg L^?1 and 100 mg L^?1, respectively. However, the germination of wheat seeds was not sensitive to exposure to tetracycline. The effects of tetracycline exposure on the microbial community in the wheat rhizosphere were evaluated through traditional cultivation and molecular biological analyses. The cultivation results indicated that bacteria were the dominant population, being present in concentrations of 1× 10⁸–2.45× 10⁹CFUs mL^?1, although 39% to 87% inhibition occurred in response to tetracycline. The concentration of fungi increased in all tetracycline treated samples to 2.5 to 15.8 times that of the control. The highest concentration of fungi (4.27× 10⁸ CFU mL^?1) was observed in response to 60 mg L^?1 tetracycline after 15 days of cultivation. In this stage, a large amount of fungal colonies was observed on the surface of the culture solution, the wheat roots became rotted and the plants became atrophic or even died. Molecular biological analysis indicated that the bacterial community structure was significantly different in samples that were exposed to high levels of tetracycline (over 20 mg L^?1) than in samples that were exposed to lower concentrations. As the concentration of tetracycline increased, the diversity of the bacteria decreased. Additionally, several dominant sensitive species such as Sphingobacterium multivorum were suppressed by tetracycline, while some resistant species such as Acinetobacter sp. appeared or were conserved. The bacteria population tended to stabilize when the drug concentration exceeded 40 mg L^?1.     

不同热处理温度对污泥厌氧发酵产氢的影响

污水处理厂污泥产生量日益增加,对环境的影响倍受关注。污泥除了含有大量的葡萄糖、蛋白质等有机物外,还包括大量的微生物,具有厌氧发酵产氢的潜能。通过批式实验系统研究了热处理污泥厌氧发酵产氢情况。研究结果表明,经过适当热处理,可以抑制耗氢菌,同时能保持产氢菌的活性,另外,对污泥还有一定的融胞作用,使污泥中溶解性的糖和蛋白质的含量增加,提高预处理污泥的产氢效率;最佳的热处理温度为75℃,处理后污泥进行厌氧发酵产氢的最大累积产氢量为18.32 mL,比产氢率3.49 mL/g VS。