Cosorption of organic chemicals with different properties: their shared and different sorption sites

Complementary sorption of different chemicals was expected and investigating the relationship between the sorption inhibition of primary sorbate (ΔQ(pri)) and sorption of secondary sorbate (Q(sec)) could provide a new angle to understand coadsorption of different chemicals. This study used bisphenol A (BPA) as the primary adsorbate, sulfamethoxazole (SMX) as the competitor, and carbon nanotubes as model adsorbents to study their complementary and competitive adsorption. At low BPA concentrations, the sorption of SMX (Q(sec)) exceeded BPA sorption inhibition (ΔQ(pri)), indicating that these two chemicals complementarily adsorbed on their respectively preferred sorption sites. At high BPA concentrations, higher ΔQ(pri) was observed in comparison to Q(sec), which may be resulted from different packing efficiencies of the adsorbed SMX and BPA. This study emphasized that both competitive and complementary sorption should be discussed in binary sorption system.     

污泥转移SBR工艺处理低浓度生活污水

污泥转移SBR工艺是一种通过内部污泥回流实现污泥在不同SBR隔室间转移,从而增加污泥利用效率,提高系统除污效能的新工艺。以设计规模为240 m3/d、处理低浓度生活污水的工艺系统为对象,研究了新工艺在不同泥转移量(污泥回流比)下的除污性能,并与系统以传统SBR方式运行的情况进行了对比。结果表明,新工艺可以有效提高SBR反应器的容积利用率;采用30%的污泥回流比进行污泥转移,新工艺的处理能力比传统SBR工艺提高近1/2,除磷效率从46%提升至85%。出水各项水质指标均能达到国家排放标准的要求。     

山地城市暴雨径流污染特性及控制对策

为了解山城重庆的暴雨径流污染特性,充实国内仍然薄弱的基础资料,对4种用地类型的4场暴雨进行了监测,测试指标包括TSS、COD、TP、TN和NH3-N。结果表明,对于坡度2.5%的交通干道和坡度30%的校园人行道,从污染物浓度降幅的角度考虑初期径流的控制量应分别为2～3 mm和1.8 mm。随降雨时间的延长,路面污染物浓度迅速降低,坡度越大,降低速率越快。对于平均浓度,校园屋顶和草坪的各污染物浓度均达到地表水环境质量Ⅴ类标准(总氮和氨氮除外)。交通干道和校园人行道的总磷平均浓度也满足地表水环境质量Ⅴ类标准,但2种下垫面的COD、TN和氨氮平均浓度分别超出地表水环境质量Ⅴ类标准的2～8倍、1.9～3.1倍和1.9～4.3倍。对于交通干道,场次降雨径流的总氮、总磷和氨氮平均浓度与初期浓度的比值和污染物浓度20 min降幅接近(分别为0.5～0.53和50%～55%)接近,而COD和TSS平均浓度与初期浓度的比值和污染物浓度20 min降幅相近(分别为0.35～0.37和78%～84%)。对于校园人行道,污染物浓度20 min降幅均达到90%以上(90%～96%),场次降雨径流的总氮、总磷、氨氮、COD和TSS的平均浓度与初期浓度的比值接近(0.3～0.4)。研究结果为山地城市暴雨径流的污染控制提供了参考。     

Fe-MCM-41催化氧化2,4-二氯苯氧乙酸

采用水热法合成了Fe-MCM-41中孔分子筛,紫外、红外及XRD表征显示铁离子已进入中孔分子筛骨架。以H2O2为氧化剂形成类Fenton试剂,实验结果表明,在催化剂加入量为1 g/L、H2O2体积分数为6%、pH为4、反应时间为10h、反应温度为35℃的条件下,处理质量浓度为50 mg/L的2,4-D废水的降解率达94.95%。宏观动力学研究显示,该反应近似为一级反应,反应速率常数、表观活化能分别为0.21667 min-1和26.65 kJ/mol。     

进水水质成分改变引发的污泥粘性膨胀及控制

在研究强化SBR工艺除污性能时,由于可溶性淀粉投加导致进水水质成分发生改变,污泥沉降性能在短时间内迅速恶化,污泥出现大量的粘液。镜检发现,大量指状菌胶团异常增殖且丝状菌的数量也逐渐减少。实验结果表明,系统膨胀属于污泥粘性膨胀。停止可溶性淀粉和提高主反应池的DO浓度,污泥粘性膨胀并未得到恢复,但污泥粘液逐渐消失。粘液消失后,通过模拟前期进水水质成分和缩短泥龄,污泥粘性膨胀得以控制,污泥沉降性能在短时间内恢复。实验还研究了污泥粘性膨胀对污染物去除性能的影响。     

陶瓷印花废水处理的混凝剂及工艺条件

采用混凝剂聚合氯化铝（PAC）、聚丙烯酰胺（PAM）、聚合硫酸铁（PFS）对陶瓷印花废水进行混凝沉降处理,监测水样的吸光度、浊度、悬浮物,以脱色率、浊度去除率、悬浮物去除率评价混凝处理的效果。结果表明：PAC是陶瓷印花废水沉降处理的理想混凝剂;水样的吸光度、浊度、悬浮物随混凝剂用量增大和沉降时间延长而呈降低趋势,而脱色率、浊度去除率、悬浮物去除率随混凝剂和沉降时间的增大呈增大的趋势;PAC投加量为20mg／L,沉降时间约为24h,水样脱色率达到90．0％,而当PAC投加量达到100mg／L,沉降时间约为4h,陶瓷印花水的脱色率可达到96．0％。证明了药剂用量的增加与沉降时间的延长对混凝过程具有增效作用。     

Development of Lignin and Nanocellulose Enhanced Bio PU Foams for Automotive Parts

The green rigid polyurethane (PU) foam has been developed with 100 % soy polyol after optimization of formulation ingredients and lignin has been introduced and isocyanate content reduced in the green rigid PU foam. The cellulosic nanofibers have also been successfully incorporated and dispersed in green rigid PU foam to improve the rigidity. The influence of nano cellulose fiber modification (enzymatic treatment, hydrophobic modification with latex) on the foam density, open cell content, foam raise height, water vapor, and mechanical properties of rigid PU foam were studied. The foamed structures were examined using scanning electron microscopy to determine the cell size and shape due to the addition of cellulosic nanofibers. The odor test were performed to evaluate the odor concentration 100 % soyol based PU foam including lignin and nanofiber and compared to 100 % synthetic based polyol PU foam. The experimental results indicated that the compression and impact properties improved due to the modification of nano cellulosic fibers. The odor concentration level of nanofiber reinforced rigid PU foam reduced significantly compared to 100 % PU foam due to the replacing of isocyanate content. It can be said that with an appropriate combination of replacing isocyanate by lignin and addition of nanofiber, rigid PU foam properties could be improved.     

As（V）在金红石TiO2颗粒表面吸附特性及机理

通过静态动力学和热力学吸附实验,研究了温度、共存离子以及溶质的初始浓度对As（V）在金红石TiO2颗粒表面吸附的影响,探讨了As（V）在金红石TiO2颗粒表面吸附特性及机理。结果表明,在As（V）初始浓度为10mg／L,pH为7的条件下,25℃时的吸附量0．41mg／g高于30℃时的吸附量0．31mg／g,As（V）在金红石TiO,上的吸附为放热过程。CaCl2和MgCl2的添加对As（V）在金红石TiO2表面吸附起到明显的促进作用。T=25℃,Ca2＋或Mg2＋浓度为10mmol／L时,As（V）吸附量分别为0．64和0．56mg／g,Ca2＋比Mg2＋对As（V）吸附促进作用强。As（V）在金红石TiO2的吸附等温线符合Frendlich方程,Lagergren二级动力学方程能较好地描述As（V）在金红石TiO2颗粒表面吸附的动力学过程。     

交联壳聚糖/沸石复合吸附剂的制备及性能

用沸石负载由缩水甘油基三乙基氯化铵交联的壳聚糖,制得了性能良好的交联壳聚糖/沸石复合吸附剂。研究了该吸附剂应用性能的影响因素,探讨了该吸附剂的吸附性、沉降性和重复使用性,利用FTIR仪和高倍透射电子显微镜对该吸附剂的结构进行了表征。实验结果表明:壳聚糖的交联度为0.93、交联壳聚糖与沸石的质量比为0.045时,制得的交联壳聚糖/沸石复合吸附剂对腐殖酸的去除率可达81.4%,吸附量为4.07mg/g;交联壳聚糖/沸石复合吸附剂对腐殖酸的吸附性能较沸石有显著提高,沉降时间较交联壳聚糖明显缩短;经二次洗脱后腐殖酸去除率仍可达80.2%,腐殖酸吸附量为4.01mg/g。     

Occurrence, distribution, and sources of six phenolic endocrine disrupting chemicals in the 22 river estuaries around Dianchi Lake in China

The objectives of this study are to track the occurrence, distribution, and sources of phenolic endocrine disrupting compounds (EDCs) in the 22 rivers around Dianchi Lake in China, to estimate the input and output amounts of phenolic EDCs in the water system, and to provide more comprehensive fundamental data for risk assessment and contamination control of phenolic EDCs in aquatic environment. Six phenolic EDCs were systematically evaluated in water and surface sediment in the estuaries of those rivers. The water and sediment samples were preconcentrated by solid-phase extraction system and microwave-assisted extraction system, respectively. Phenolic EDCs were analyzed by GC-MS (Thermo Fisher Scientific, USA) after derivatization. Phenolic EDCs were found ubiquitously in the aquatic environment. The total concentrations ranged from 248 to 4,650 ng/L in water, and 113 to 3,576 ng/g dry weight in surface sediment. The residue amount of phenolic EDCs in Dianchi Lake was 258 kg/a. Concentrations of the phenolic EDCs in the Lake decreased with increase in distance to the estuaries of those rivers which run through urban and industrial areas. The rivers seriously contaminated by phenolic EDCs were Xin River, Yunliang River, Chuanfang River, Cailian River, Jinjia River, Zhengda River, and Daqing River which run through the old area of Kunming City. Satisfying correlations were observed between the concentrations of the target compounds in water and in surface sediment. NP1EO, NP2EO, and BPA were identified as the three predominant phenolic EDCs. There were significant correlations between phenolic EDCs and many basic water quality parameters. Urban and industrial areas are the major contributors for phenolic EDCs, especially in Kunming City. Compositional profiles of phenolic EDCs in surface sediment were similar to those in river water. The concentrations of phenolic EDCs in the rivers located in the northwest part of the valley were very high, and posed a potential risk to aquatic organisms and even human. The concentrations of NP2EO, NP1EO, and BPA were at moderate levels of other areas. The basic water quality parameters (TOC, TN, DO, and pH) play important roles on the distribution, fate, and behavior of phenolic EDCs in the valley.