改性蒙脱土颗粒吸附直接染料的分形特征

研究了改性蒙脱土颗粒(050823和MMT35)吸附2种直接染料(直接耐晒黑G和直接大红4BE)的吸附特性,并从类分形动力学规律、颗粒吸附染料前后的表面分形特征变化等方面对上述吸附过程进行了探讨.结果表明,颗粒对染料的吸附可分为快速的边缘覆盖和缓慢的晶层吸附2个过程.整个吸附过程符合准-二级反应动力学方程,并且染料进入晶层的吸附阶段具有类分形特征.除MMT35-直接大红4BE染料吸附体系外,Freundlich、Langmuir吸附等温模型的非线性方程、不同形式的线性方程及分形Langmuir模型对其余3个吸附体系(050823-直接耐晒黑G、050823-直接大红4BE、MMT35-直接耐晒黑G)等温线数据的模拟均取得了较好的效果,其中,非线性方程是获得统一模型参数较好的方法.此外,染料分子主要通过静电引力/斥力和范德华引力的综合作用吸附在颗粒上,并通过晶层膨胀和开孔作用,使颗粒表面粗糙度增加,相应的表面分形维数Ds升高.     

Degradation of Reactive Yellow 86 with photo-Fenton process driven by solar light

The decolorization of Reactive Yellow 86(RY 86),one of reactive azo dyes,was investigated in the presence of Fenton reagent under solar light irradiation.The decolorization rate was strongly influenced by pH,initial concentrations of H 2 O 2 and Fe(II),and so on.An initial concentration of 40 mg/L was decolored more than 90% after 20 min under optimum conditions.The activation energy of the solar photo-Fenton reaction was 1.50 kJ/mol for RY 86 in the temperature range of 10-60°C.In the kinetic study,the rate constant of RY 86 with OH· radicals could be estimated to be 1.7 × 10 10 L/(mol·sec).The decolorization efficiency of RY 86 under solar light irradiation was comparable to the artificial light irradiation.The decrease of TOC as a result of mineralization of RY 86 was observed during photo-Fenton process.The rate of RY 86 mineralization was about 83% under UV irradiation after 24 hr.The formation of chloride,sulfate,nitrate and ammonium ions as end-products was observed during the photocatalytic process.The decomposition of RY 86 gave two kinds of intermediate products.The degradation mechanism of RY 86 was proposed on the base of the identified intermediates.     

柚子皮吸附剂的物化特性研究

柚子皮对染料具有一定吸附作用。文章为进一步探讨柚子皮吸附机理,对与吸附染料相关的柚子皮物化特性进行了研究,主要包括:柚子皮的基本化学元素含量、化学基团、含水量、灰分、挥发分、综纤维素含量、等电点(pHpz)c、比表面积(BET)、表面显微结构等,并检测了柚子皮及其浸出液中重金属含量。结果显示柚子皮具有丰富的多孔结构,平均孔径约为2～20μm,该孔隙结构有利于吸附染料大分子。柚子皮综纤维素含量非常高,并含有大量可与染料分子结合的羟基和羰基基团。在柚子皮及其浸出液中未检出砷、镉、钴、铬、铅等常见的有毒重金属,所以将柚子皮做为吸附剂应用在废水处理中,不会带入有毒金属物质。     

废催化剂再生后对甲基橙的吸附动力学研究

废催化剂为生产醋酸乙烯过程中产生的废弃物,经过热处理直接得到ZnO／活性炭。以ZnO／活性炭为吸附剂,进行了吸附水溶液中甲基橙（MO）实验,在优化条件下,实验浓度范围内甲基橙溶液的吸附去除率均高于97％,表明ZnO／活性炭适于吸附甲基橙。采用准二级动力学模型和粒子内扩散模型研究ZnO／活性炭对水溶液中甲基橙的吸附动力学,并计算得到动力学参数和相关系数。结果表明,两种模型较好地描述了实验数据,其吸附过程的速率控制步骤为膜扩散控制,并随溶液初始浓度的增加准二级速率常数降低,面内扩散速率常数增加。     

水稻不同生育期土壤砷形态分布特征及其生物有效性研究

采用田间原位试验和Tessier连续提取方法,在水稻（Oryza sativa L.）不同生育期研究了重金属复合污染高、中、低3个水平下的土壤砷的形态分布特征及其生物有效性。结果表明：在水稻不同生育期中,土壤各种形态的砷质量分数均表现为高污染水平土壤〉中等污染水平土壤〉低污染水平土壤;土壤中砷在水稻整个生育期均以残留态为主,占90%以上,交换态砷所占比例最低,不到0.5%;不同形态砷之间大都显著正相关,但是两种有效性较高的砷形态（交换态和碳酸盐结合态）与有机态砷之间的相关性较差;土壤砷的生物有效性表现为高污染水平土壤〉中等污染水平土壤〉低污染水平土壤,且随着水稻生育期的延长,土壤砷的生物有效性逐渐升高。     

活性染料染色废水脱色效果的研究

通过用一种天然有机高分子化合物制备的复合絮凝剂在活性染料染色废水处理中应用,并与无机高分子混凝剂聚合铝铁、聚合氯化铝进行脱色效果的比较,发现其在酸性和近中性条件下对酸性、活性、分散、还原等染料均有较好的混凝脱色效果,同时通过对回流污泥工艺的改进可减少沉降时间。     

取代苯酚类化合物抑藻活性的CoMFA模型

基于比较分子力场分析(CoMFA)方法建立20种取代苯酚类化合物抑藻活性(pI)的三维定量构效关系(3D-QSAR)。训练集中16个化合物用于建立预测模型,测试集5个化合物(含模板分子)作为模型验证。已建立的Co MFA模型的交叉验证系数(Q2)、非交叉验证系数(R2)分别为0.915、0.963,说明所建模型具有较强的稳定性和良好的预测能力。该模型中立体场、静电场贡献率依次为48.4%、51.6%,表明影响抑藻活性(pI)的主要因素是取代基的电荷分布,其次是取代基的疏水性和空间位阻。     

Simultaneous removal of hydrogen sulfide and volatile organic sulfur compounds in off-gas mixture from a wastewater treatment plant using a two-stage bio-trickling filter system

A two-stage BTF system was established treating odorous off-gas mixture from a WWTP. The two-stage BTF system showed resistance for the lifting load of H₂S and VOSC. Miseq Illumina sequencing showed separated functional microbial community in BTFs. Avoiding H₂S inhibition and enhancement of VOSC degradation was achieved. Key control point was discussed to help industrial application of the system. Simultaneous removal of hydrogen sulfide (H₂S) and volatile organic sulfur compounds (VOSCs) in off-gas mixture from a wastewater treatment plant (WWTP) is difficult due to the occasional inhibitory effects of H₂S on VOSC degradation. In this study, a two-stage bio-trickling filter (BTF) system was developed to treat off-gas mixture from a real WWTP facility. At an empty bed retention time of 40 s, removal efficiencies of H₂S, methanethiol, dimethyl sulfide, and dimethyl disulfide were 90.1, 88.4, 85.8, and 61.8%, respectively. Furthermore, the effect of lifting load shock on system performance was investigated and results indicated that removal of both H₂S and VOSCs was slightly affected. Illumina Miseq sequencing revealed that the microbial community of first-stage BTF contained high abundance of H₂S-affinity genera including Acidithiobacillus (51.43%), Metallibacterium (25.35%), and Thionomas (8.08%). Analysis of mechanism demonstrated that first stage of BTF removed 86.1% of H₂S, mitigating the suppression on VOSC degradation in second stage of BTF. Overall, the two-stage BTF system, an innovative bioprocess, can simultaneously remove H₂S and VOSC.     

响应曲面法优化油茶饼对活性红15的生物吸附特征及机理

基于“以废治废”的理念,以农林业废弃物——油茶饼为原料制备生物吸附剂,吸附去除废水中的RR15(C.I. Reactive Red 15,活性红15)染料,并采用响应曲面法中的Box-Behnken设计对油茶饼生物吸附剂吸附RR15的条件进行优化. 结果表明:pH对油茶饼生物吸附剂吸附RR15的吸附容量和去除率均有显著影响(P<0.000 1);当pH为1.0、初始ρ(RR15)为300 mg/L、吸附温度为20 ℃时,油茶饼生物吸附剂对RR15的吸附效果最佳. 相比于Langmuir和Freundlich吸附等温线模型,Temkin吸附等温线模型可以更好地描述油茶饼生物吸附剂对RR15的吸附平衡数据. 吸附温度为20 ℃时,由Langmuir吸附等温线模型计算得到的Q0(吸附剂的单层饱和吸附量)为74.63 mg/g. 动力学分析显示,油茶饼生物吸附剂对RR15的吸附过程符合准二级动力学模型(R2>0.999 7),支持了限速步骤是化学吸附的理论;内部扩散和边界层扩散都可能影响吸附速率. 热力学分析表明,该吸附过程是一个自发的放热过程. FTIR(fourier transform infrared spectroscopy,傅里叶变换红外光谱)分析发现,油茶饼生物吸附剂上羟基、胺基等官能团可能是RR15染料的主要结合位点. 研究显示,油茶饼生物吸附剂是一种具有潜力的绿色吸附剂,可以有效去除废水中的RR15染料.      

组合流反应器启动运行试验

以含氮磷的模拟生活污水为处理对象,对自行设计的推流、折流与完全混合流的组合流动反应器进行启动试验研究。试验分为两个部分,首先对普通活性污泥进行驯化培养,然后将驯化好的活性污泥移到组合流反应器内,加入污水进行连续启动运行。试验连续运行30 d,结果表明在启动运行后期,COD、TP、氨氮的去除率分别达85%、80%及70%以上,好氧区硝态氮的累积率稳定在28 mg/L,说明组合流反应器启动成功。