Hexabromocyclododecanes in surface sediments and a sediment core from Rivers and Harbor in the northern Chinese city of Tianjin

In the present study, hexabromocyclododecanes (HBCDs) were investigated in the sediment from Haihe River (HR), Dagu Dainage Canal (DDC) and Tianjin Harbor (TH) at Bohai Bay using a total of 51 samples of surface sediments and a sediment core collected from May to September in 2010, and its diastereomer- and enantiomer-specific profiles were analyzed. The concentration of total HBCDs were generally high, with mean value and ranges of 31.0 and 1.35–634 ng g^?1 dw, respectively. The contamination followed the order of TH > DDC > HR. Higher levels (up to 634 ng g^?1 dw) occurred in the lower reach of HR and DDC located in an industrial area of Tianjin. This is the first time to report so high concentration of HBCDs in sediment in Southeast Asia. The γ-diastereomer dominated in most samples (44 out of 51), and this is in agreement with the diastereomer distribution pattern in industrial products, while α-HBCD was the dominant diastereomer in the other seven samples. However, only few samples exhibited γ-diastereomer ratio similar to that (75–89%) in technical products, indicating the inter-transformation and variable degradation of the different isomers. The high ratio of γ-diastereomer could be used as an indicator for fresh contamination input. Enantiomeric factors (EFs) of HBCD isomers in most of the samples were statistically different from technical products (p < 0.05), showing a trend of more easily enrichment of the (?)-HBCD-enantiomer compared to the (+)-HBCD-enantiomer. The δ- and ε-diastereomers were frequently detected but at low level. The HBCDs in the sediment core showed several peaks, and the greatest value occurred in 2005, when a plastic manufacture plant using HBCD was set up nearby.     

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) in biosolids from municipal wastewater treatment plants in China

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) along with methoxylated polybrominated diphenyl ethers (MeO-PBDEs) have been frequently identified as natural compounds in marine environment and also assumed as metabolites of PBDEs. In the present study, nine OH-PBDE, nine MeO-PBDE and 10 PBDE congeners were studied in the sewage sludge collected from 36 municipal wastewater treatment plants (WWTPs) in 27 cities of China. The results suggest that OH-PBDEs and PBDEs are ubiquitous in sewage sludge in China, however, methoxylated PBDEs were not detectable. Composition profiles of detected OH-PBDE congeners were different depending on the sampling location. ΣOH-PBDEs in WWTPs sludge ranged from 0.04 to 2.24 ng g^?1 dry weight (mean: 0.35 ng g^?1 dry weight). The total amount of the two most prominent congeners (6-OH-BDE-47 + 2′-OH-BDE-68) accounted for about 53.3–100% of the sum of all six identified congeners. A significant linear relationship was found between 6-OH-BDE-47 and 2′-OH-BDE-68. A distinct geographical distribution of ΣOH-PBDEs was observed with greater concentrations of OH-PBDEs at coastal areas than inland regions in China.     

Facile, effective, and environment-friendly degradation of sulfamonomethoxine in aqueous solution with the aid of a UV/Oxone oxidative process

The degradation of sulfamonomethoxine (SMM) in the aqueous environment by the combination of UV illumination and Oxone has been studied. Experimental results indicated that the UV illumination can effectively activate Oxone to produce sulfate-free radicals (SO₄ ^??). When 10 mmol L^?1 Oxone was added, 96.78 % removal of SMM (5 mg L^?1) was achieved within 90 min. Mineralization of SMM was investigated by measuring the total organic carbon, which decreased by 89.01 % after 90 min reaction. Six intermediate compounds generated during the SMM degradation were identified with the aid of liquid chromatography and mass spectroscopy, combined with proton nuclear magnetic resonance spectroscopy. A general reaction pathway for the degradation of SMM was proposed, where the presence of SO₄ ^?? remained crucial during the degradation process.     

生物填料地下渗滤系统对生活污水的脱氮

将草甸棕壤、炉渣和活性污泥等基质按体积比13∶6∶1配制生物填料,研究了生物填料地下渗滤系统（subsurface wastewater infiltration system,SWIS）在不同的水力负荷和污染负荷条件下对校园生活污水的脱氮效果。场地实验结果表明,当BOD5负荷为12.0 g BOD5/（m2·d）,表面水力负荷为0.04-0.10 m3/（m2·d）时,SWIS对NH＋4-N和TN的平均去除率分别为92.4%和82.0%。当水力负荷为0.08 m3/（m2·d）,BOD5负荷9.3-16.8 g BOD5/（m2·d）时,SWIS对NH＋4-N和TN的平均去除率为92.7%和81.2%。SWIS中氧化还原电位（oxygen reduction potential,ORP）随进水水力负荷和BOD5负荷的增加而降低,脱氮效率下降。综合出水水质和处理效率,适宜的水力负荷和污染负荷分别为0.065 m3/（m2·d）和12.0 g BOD5/（m2·d）。在此条件下,SWIS的启动周期为25-30 d。出水水质均优于《城市污水再生利用-景观环境用水水质》（GB/T18921-2002）标准,且处理效果稳定,抗负荷冲击能力强。     

矿化垃圾床＋三维电极／电Fenton法处理老龄垃圾渗滤液

提出以二级矿化垃圾床为预处理单元,串联三维电极／电Fenton处理老龄垃圾渗滤液的组合工艺。矿化垃圾床处理后渗滤液中COD、氨氮、总磷、色度的去除率分别为80．55％、88．47％、98．32％和87．53％。通过单因素实验和正交实验,确定了三维电极／电Fenton法最佳工艺条件。经该组合工艺后,渗滤液中COD、氨氮、总磷和色度的最高去除率分别可达97．08％、95．24％、99．55％和96．92％,其中COD、总磷、色度这3个指标低于《生活垃圾填埋场污染控制标准》（GB16889．2008）表2规定的排放标准,为该组合工艺在实际中的应用提供重要理论依据。     

季节性城市生活垃圾成分分析及厌氧消化特性研究

城市生活垃圾的成分及特性随着季节和人类在不同季节的生活习惯而变化,针对我国北方城市研究了一年中不同季节的城市生活垃圾成分特点,对影响厌氧发酵过程的相关成分如总有机碳（TOC）、总氮（TN）、蛋白质、脂肪和还原糖等进行了测定分析。通过厌氧消化实验,测得不同季节城市生活垃圾pH值、日产气量、沼气甲烷含量、甲烷累积量、挥发性脂肪酸（VFAs）和氧化还原电位（ORP）等参数的变化规律,分析相应变化的影响因素。结果表明,二、三季度的含水率分别为64．81％和67．50％,高于一、四季度,一季度发酵原料中蛋白质和脂肪含量分别为12．56％和8．86％,明显高于其他3个季度。一季度甲烷累积量最高,达到17616mL,单位发酵原料的产气量为204．8mL／g,也是4个季度中最高的,说明蛋白质、脂肪等有机成分含量对厌氧发酵过程及结果影响比较明显。为进一步的城市生活垃圾厌氧消化制取生物燃气的工艺条件提供依据。     

骨炭对水中不同形态Sb吸附和解吸的影响

采用骨炭作为吸附剂,研究其在不同骨炭用量、pH值和温度条件下对水中Sb（Ⅲ）和Sb（Ⅴ）吸附和解吸的影响。结果表明,骨炭对Sb（Ⅲ）的吸附效果远好于Sb（Ⅴ）,在0.2~8.0 mmol/L的Sb（Ⅲ）和Sb（Ⅴ）浓度下,骨炭对这2种形态Sb的去除率分别为46.1%~78.6%和9.6%~31.7%。采用Langmuir方程和Freundlich方程均可以很好地拟合骨炭对Sb（Ⅲ）和Sb（Ⅴ）的吸附,Sb（Ⅲ）和Sb（Ⅴ）的最大吸附容量分别为110.1034 mg/g和17.4167 mg/g。骨炭对Sb（Ⅲ）的解吸也大于对Sb（Ⅴ）的解吸。骨炭对Sb（Ⅲ）和Sb（Ⅴ）的吸附受不同骨炭用量、pH值和温度影响。     

电吸附对水中盐类、氨氮、COD的去除效果分析

电吸附技术作为高效、环境友好型的除盐、除氨氮技术,可应用与水的深度处理领域内。为了使污水回用达到工业用水的水质标准,对电吸附去除水中盐类、氨氮、COD的效果进行分析,结果表明,电吸附设备处理不同氨氮浓度的废水,对中低浓度的氨氮去除效果稳定,当进水氨氮浓度低于20 mg/L时,处理后出水氨氮浓度低于5 mg/L,COD浓度小于25 mg/L,达到回用标准;随着进水盐浓度的增大电吸附处理效果逐渐变差,在电导率低于2 500 μS/cm时除盐率在75%左右,氨氮去除率达到70%左右,COD去除率达到60%左右。经电吸附处理后的低氨氮浓度废水,TDS、氨氮浓度均可达到工业回用水标准。     

漆酶对活性黑KN-B和直接大红染料的脱色性能

利用白腐真菌漆酶对活性黑KN-B和直接大红2种偶氮染料进行脱色实验。考察反应时间、加酶量、pH值、染料浓度、温度对脱色率的影响,研究了ABTS介体以及金属离子存在下的脱色效果,并分析了漆酶脱色的动力学性能以及其对偶氮染料的降解规律。结果表明,活性黑KN-B和直接大红脱色适宜条件为：反应时间为30 min,加酶量8 U/mL,pH=7,染料浓度分别为50 mg/L和80 mg/L,温度40~45℃。ABTS介体对酶促偶氮染料脱色没有明显促进作用。Fe²⁺对漆酶脱色有较强的抑制作用;Cu²⁺对漆酶催化活性黑KN-B促进作用较大,对直接大红影响较小。漆酶对2种染料的脱色反应符合米氏方程,其催化活性黑KN-B和直接大红染料的K_m值分别为114.81 mg/L,317.5 mg/L,v_max值分别为6.57 mg/（L·min）和26.0 mg/（L·min）。     

铁炭微电解法降解TAIC废水

TAIC（三烯丙基异氰脲酸酯）作为过氧化物交联或自由基反应交联的助交联剂被广泛应用。由于TAIC性质稳定难于生物降解,采用铁炭微电解法处理TAIC生产废水,并考察了铁炭比、进水pH值、反应时间对处理效果的影响,以及TAIC降解机理和反应动力学过程。结果表明,影响微电解工艺的因素主次关系为：pH>Fe/C质量比>反应时间;在最佳条件进水pH值为5,铁炭质量比为2：1,反应时间为135 min时,COD的去除率达到46%以上,TAIC的去除率达到48%以上。TAIC去除机理研究表明,微电解对TAIC废水的作用主要通过·H的还原和铁离子的絮凝作用,其中·H的还原作用是TAIC降解的主要原因。反应动力学分析表明,铁炭微电解法处理TAIC的降解过程基本符合二级反应动力学规律,通过建立模型并拟合出了TAIC降解的二级反应动力学方程。