双氧水协同生化法强化处理印染废水

传统生化法对印染废水的处理有一定的局限性.本文研究了双氧水协同水解酸化-接触氧化系统,对印染废水进行强化处理.采用污泥挂膜、生化系统启动、双氧水协同启动的方法,将双氧水投加到水解酸化时的条件严格控制为:投加3m L·L~(-1)、投加量100.0 m L、流速0.67 m L·min-1、投加频率1次·d-1,可使整个系统成功启动与稳定运行.实验结果表明,双氧水协同水解酸化-接触氧化可对印染废水中的特征污染物进行有效强化处理.其中,COD平均去除率为89.8%,氨氮平均去除率为96.7%,PVA平均去除率为87.4%,废水平均脱色率为92.1%.采用16S rDNA宏基因组高通量测序技术,对比分析了接种种泥、水解酸化污泥和接触氧化污泥微生物的群落结构.结果表明,经过驯化,水解酸化和接触氧化微生物群落均发现了显著变化.其中,水解酸化污泥优势菌门主要为变形菌门Proteobacteria、拟杆菌门Bacteroidetes和疣微菌门Verrucomicrobia;接触氧化污泥优势菌门主要为浮霉菌门Planctomycetes、变形菌门Proteobacteria和酸杆菌门Acidobacteria.该实验从宏观和微观角度,均证实双氧水协同生化法强化处理印染废水具有技术可行性.     

村镇生活垃圾与秸秆混合焚烧过程中多环芳烃(PAHs)释放特征

为了解我国农村地区生活垃圾与玉米秸秆焚烧处置过程烟气中多环芳烃(PAHs)释放特征,对我国农村地区生活垃圾可燃组分以及生活垃圾与玉米秸秆混合焚烧组分在焚烧过程烟气中PAHs化合物释放特征进行分析,利用气相色谱-质谱仪(GC-MS)对样品中的16种PAHs进行分析,研究气态以及颗粒态PAHs的释放因子、环数比例、气固态分配以及排放特征值.结果表明气态PAHs排放因子为当垃圾与秸秆混合比例为1∶2时PAHs的总量最多,而颗粒态为当垃圾与秸秆混合比例为1∶3时PAHs的总量最多;气态PAHs主要集中于2～3环低环数化合物,颗粒态PAHs则主要以中低环数(3～4环)化合物为主,本研究为促进我国村镇生活垃圾处理与资源化运用提供理论依据.     

基于DALYs的北京市大气PM2.5载带苯并[a]芘疾病负旦研究

苯并[a]芘(BaP)是一类兼具强致癌性和非致癌毒性的物质,可随PM_(2.5)经呼吸途径进入人体而威胁健康.本文采集2016年北京城区监测点PM_(2.5)样品并采用气相色谱质谱联用仪测定其载带BaP浓度.通过BaP的流行病学及动物毒理学数据的检索和分析,确定BaP呼吸暴露的致癌和非致癌毒效应评价终点及其剂量效应关系.运用伤残调整生命年(DALYs)指标估算了呼吸途径人群PM_(2.5)载带BaP暴露导致的疾病负担.结果显示北京市BaP导致总疾病负担为431.36 DALYs·a~(-1),每千人DALYs为0.03 a~(-1).其中非致癌效应的疾病负担为1.98 DALYs·a~(-1),致癌效应为429.39 DALYs·a~(-1).不同毒效应的疾病负担排序为:癌症(99.54%)发育毒性(0.41%)生殖毒性(0.04%).不同季节的疾病负担贡献差异较大.北京市BaP暴露导致疾病负担的主要贡献季节为冬季,疾病负担贡献的顺序为冬季(88.01%)秋季(4.91%)春季(4.34%)夏季(2.74%).     

环氧树脂降解嗜盐菌的筛选及其处理高盐环氧树脂废水的特性研究

从环氧树脂废水生化处理系统的活性污泥中分离筛选得到2株嗜盐菌,并对其进行分子生物学鉴定,考察了生长和降解特性.结果表明,通过菌株的形态观察及16S rDNA序列比对分析,菌株J1归属于芽孢杆菌属(Bacillus sp.),菌株J2属于枝芽孢杆菌属(Virgibacillus sp.).菌株J1和J2在高盐CM培养基中的适宜生长条件为:温度30℃,pH为7.0,NaCl的浓度范围为5～50 g.L-1.对环氧树脂废水中有机物的最佳降解条件为:温度30℃,pH为7.0,NaCl浓度30 g.L-1.将菌悬液J1和J2按2∶1的体积比例混合后,在复合菌种的接入量为10%时,对环氧树脂废水中COD的去除率最高.     

超声波辅助化学萃取对某工业场地铅污染土壤修复效果研究

以某铅蓄电池厂污染场地5个铅污染区域(WS、A、B、C及BZ)的土壤为研究对象,对土壤中铅全量及各形态含量进行分析.在0.1 mol.L-1EDTA,30 min,25℃相同条件下,使用超声波辅助化学洗脱(ultrasonic-assisted chemical extraction,UCE)与传统化学洗脱(conventional chemical extraction,CCE)两种不同的作用方式,对铅的去除效率进行比较,并对两种不同清洗方式后铅的形态变化进行了探讨.结果表明,UCE对铅的去除效率显著优于CCE.在CCE作用下,5份污染土壤WS、A、B、C、BZ铅的去除效率依次为10.06%、48.29%、48.69%、53.28%及36.26%,而UCE作用下铅的去除效率依次为22.42%、69.31%、71.00%、74.49%及71.58%,平均效率高出22%.通过对比两种清洗方式后土壤中的铅形态发现,酸可提取态在UCE作用后持平或有所降低,但CCE后使酸溶态有增高的趋势;对于铁锰氧化态,UCE对其有着极好的去除能力,可达98%左右,同时对有机物及硫化物结合态、残渣态也具有较好的去除能力.因此,UCE在化学萃取中的应用具有一定的可行性,是一种简单、极快速去除污染场地中重金属铅的增效手段.     

室内组合家具全尺寸燃烧实验研究

以室内组合家具为研究对象,以研究组合家具与单体家具燃烧的区别和研究组合家具燃烧特征为目的,通过全尺寸燃烧实验,得到结论:组合家具燃烧不同于单体家具,其燃烧过程中,各个家具的燃烧相互影响相互促进;燃烧过程中通风口位置存在一个分界面,界面两侧温度差别较大;燃烧结束后的痕迹分析可以为火灾鉴定提供参考依据。     

Organochlorine pesticides in the surface water and sediments from the Peacock River Drainage Basin in Xinjiang, China: a study of an arid zone in Central Asia

Fourteen surface water and nine surface sediment samples were collected from the Peacock River and analyzed for organochlorine pesticides (OCPs) by gas chromatograph?Celectron capture detector (GC-ECD). All the analyzed organochlorine pesticides, except o,p ^??-DDT, were detected in sediments from the Peacock River; but in the water samples, only ??-HCH, HCB, p,p ^??-DDD, and p,p ^??-DDT were detected at some sites. The ranges for total OCPs in the water and sediments were from N.D. to 195 ng l^???1 and from 1.36 to 24.60 ng g^???1, respectively. The only existing HCH isomer in the water, ??-HCH, suggested that the contamination by HCHs could be attributed to erosion of the weathered agricultural soils containing HCHs compounds. Composition analyses showed that no technical HCH, technical DDT, technical chlordanes, endosulfans, and HCB had been recently used in this region. However, there was new input of ??-HCH (lindane) into the Peacock River. The most probable source was water flowing from Bosten Lake and/or agricultural tailing water that was returned directly into the Peacock River. DDT compounds in the sediments may be derived mainly from DDT-treated aged and weathered agricultural soils, the degradation condition was aerobic and the main product was DDE. HCB in the sediment might be due to the input from Bosten Lake and the lake may act as an atmospheric deposition zone. There was no significant correlation between the concentrations of OCPs (including ??HCH, ??DDT, chlordanes, endosulfans, HCB and total OCPs) and the content of fine particles (<63 ??m). The concentrations of OCPs were affected by salinity.     

广州市供水水源面临的问题和对策

通过分析广州市现有的水资源情况和饮用水的供水情况、地表水源和地下水水源概况等资料,针对广州市饮用水源面临的严峻形势,提出广州市应建设以地下水作为应急饮用水源,构建复合水源体系的规划。     

Removal of bromate ion using powdered activated carbon

Bromate ion (BrO 3) removal from drinking water by powdered activated carbons (PAC S) in bath mode was evaluated under various operational conditions.Six kinds of PACs,including wood-based carbon,fruit-based carbon,coal-based carbon,and these three carbons thermally deoxidized in a nitrogen atmosphere,were selected to investigate their capacity on BrO 3 removal.With the highest zeta potential value and being richly mesoporous,coal-based carbon had a high and an excellent BrO 3 adsorption efficiency.The removal content of BrO 3 by per gram of coal-based carbon was 0.45 mg within 5 hr in 100 μg/L bromate solution.The surface characteristics of PACs and bromide formation revealed that both physical and chemical PACs properties simultaneously affected the adsorptionreduction process.Under acidic conditions,PAC S possessed high zeta value and adequate basic groups and exhibited neutral or positive charges,promoting BrO 3 adsorption-reduction on the carbon surface.Interestingly,the PAC S thermally deoxidized in N 2 atmosphere optimized their properties,e.g.increasing their zeta values and decreasing the oxygen content which accelerated the BrO 3 removal rate.The maximum adsorption capacity of fruit-based carbon was the highest among all tested carbons (99.6 mg/g),possibly due to its highest pore volume.Remarkably,the thermal regeneration of PACs in N 2 atmosphere could completely recover the adsorption capacity of PACs.The kinetic data obtained from carbons was analyzed using pseudo second-order and intraparticle diffusion models,with results showing that the intraparticle diffusion was the more applicable model to describe adsorption of BrO 3 onto PACs.     

Fluxes of CH4 and N2O from soil under a tropical seasonal rain forest in Xishuangbanna, Southwest China

CH4 and N2O fluxes from soil under a tropical seasonal rain forest in Xishuangbanna, Southwest China were measured for one year using closed static chamber technique and gas chromatography method. Three treatments were set in the studied field: (A) litter-free,(B) with litter, and (C) with litter and seedling. The results showed that the soil in our study was a sink of atmospheric CH4 and source of atmospheric N2O. The observed mean CH4 fluxes from treatments A, B, and C were -50.0±4.0, -35.9±2.8,-31.6±2.8 μgC/(m2·h),respectively,and calculated annual fluxes in2003 were -4.1,-3.1,and -2.9kgC/hm2,respectively.The observed mean N2O fluxes from treatments A,B,and C were 30.9±3.1,28.2±3.5,50.2±3.7μgN/(m2·h),respectively,and calculated annual fluxes in 2003 were 2.8, 2.6, and 3.7 kgN/hm2, respectively. Seasonal variations in CH4 and N2O fluxes were significant among all the three treatments. The presence of litter decreased CH4 uptake during wet season (P ＜ 0.05), but not during dry season. There was a similar increase in seedlings-mediated N2O emissions during wet and dry seasons, indicating that seedlings increased N2O emission in both seasons. A strong positive relationship existed between CH4 fluxes and soil moisture for all the three treatments, and weak relationship between CH4 fluxes and soil temperature for treatment B and treatment C. The N2O fluxes correlated with soil temperature for all the three treatments.