好氧生物降解改进的MITI(Ⅰ)试验方法研究

好氧生物降解改进的MITI(日本通商产业省)(Ⅰ)试验是用来评估化学品在特定温度条件下是否具有快速生物降解性的有效方法。以环境内分泌干扰剂壬基酚为受试物,应用改进的MITI(Ⅰ)试验对其生物降解性进行研究,亦对试验所需污泥进行驯化培养,并对污泥特性进行检测。试验结果表明处理28d后,壬基酚生物降解率为51.4%,不具有快速生物降解性,参比物苯甲酸钠生物降解率为89.1%。在污泥培养过程中,污泥重量、体积变化规律为随培养期的增加污泥重量、体积逐渐增大,后逐渐趋于稳定。污泥活性的变化规律为随培养期增加,污泥活性先增强,后逐渐趋于稳定。     

脂肪醇聚氧乙烯醚的厌氧与好氧生物降解性

以脂肪醇聚氧乙烯醚(AEO)为目标污染物，在等同条件下做厌氧消化污泥和好氧活性污泥对其生物降解性能的对比实验，得出了同一系列AEO分子中聚氧乙烯基与整个分子的降解难易程度的关系。表明：①污泥会对AEO分子产生吸附一脱附作用而出现假降解率，克服假降解率的干扰是准确测定AEO生物降解性的关键因素；②厌氧和好氧条件下，AEO均可降解，但厌氧降解要稍优于好氧降解；③AEO中聚氧乙烯基的单元数(n)是影响其生物降解的重要因素，相同碳链的直链烷基，生物降解率随n的增加而明显降低。     

好氧颗粒污泥的快速培养以及胞外多聚物对颗粒化的影响研究

采用普通活性污泥、部分好氧颗粒污泥和部分厌氧颗粒污泥分别作为接种污泥培养好氧颗粒污泥。在操作条件相同的情况下比较三者颗粒化的过程与完成时间。同时,研究胞外多聚物(EPS)对好氧污泥颗粒化的影响。结果显示,预先投加部分好氧颗粒污泥可以大大缩短好氧颗粒污泥的形成时间,胞外多聚物与污泥的颗粒化有密切联系。     

油田驱采出水中聚丙烯酰胺在SBR中的生物降解特性研究

采用人工配制的模拟含聚(聚丙烯酰胺,PAM)驱采出水为介质,在以好氧颗粒污泥为主体的实验型SBR内研究了油田驱采出水中PAM的生物降解性能。结果表明,好氧颗粒污泥对含聚驱采出水有良好的适应性,在相同的水力停留时间下,PAM降解率比普通活性污泥高约40倍。驯化后的颗粒形态发生明显变化,粒径减小到0．6～1．0mm。     

吸附-生物降解法处理含挥发性有机物废水

采用吸附-生物降解法处理含碳氢溶剂挥发性有机物(VOCs)的水洗废水,研究了废水中挥发性有机成分的非稳性,考察了2种活性污泥(厌氧、好氧污泥)对废水中挥发性有机物的吸附性能,探讨了厌氧-好氧组合工艺对水洗废水的降解效能,分析了处理工艺的运行效果.结果表明,水洗废水中的VOCs易再次挥发,曝气状态下VOCs的最大挥发率为...     

好氧颗粒污泥处理城市生活污水性能研究

好氧颗粒污泥是在好氧环境中形成的一种特殊生物聚集体,可在同一生物体内构造多种氧环境与营养条件,具有远大的发展前景。采用好氧颗粒污泥技术对城市生活污水处理进行研究,探索各因素对好氧颗粒污泥的性能与稳定性影响,优化反应器运行参数,为实现快速启动与稳定运行的好氧颗粒污泥系统提供理论支持。     

新产品·新技术·新设备

好氧生物处理除去造纸废水中的木质素木质素是不易生物降解的,但是采用连续或间歇好氧反应器生物处理造纸工厂废水,能够降低溶解木质素的浓度。试验结果表明:木质素通过生物降解或吸附在生物污泥上而被除去,试验采用在好氧生物反应器中污泥停留时间分别为1 0、1 5、2 0、30和40d ,并用热解气相色谱法和质谱-光谱法测定了液体中与不同停留时间污泥试样中木质素的含量。通过测定发现,有一种情况是木质素吸附在活性污泥上的量为≤30 % ,意味着这种活性污泥具有极好的吸附木质素的性能,通过洗涤污泥可达到除去木质素的目的。在好氧生物反应器中,…     

一种双子型双酯类阳离子表面活性剂的生物降解行为研究

以环氧氯丙烷、十八烷基二甲基叔胺和己二酸为反应原料,制备了一种包含双酯结构的双子(Gemini)型阳离子表面活性剂,通过傅里叶变换红外光谱和元素分析确定了产物结构。采用好氧污泥的方法研究所制备表面活性剂的生物降解性能,并进一步研究了降解动力学特性,发现在一定条件下,这种表面活性剂的完全降解时间为8 d,且降解过程符合二级动力学模型。     

污泥有机污染物降解研究进展

城市污水处理过程迁移并富集在污泥中的有机污染物稳定性高、难降解，存在较高的生态风险，已成为制约污泥土地利用的主要因素。考虑到物化法处理污泥有机污染物的工程局限性，本文介绍了城市污泥中多环芳烃、苯并(a)芘与矿物油3种代表性有机污染物的来源、性质及危害。围绕污泥厌氧消化、好氧堆肥以及两者联合的作用机理，论述了有机污染物在污泥处理过程中的降解转化规律。分析了有机污染物降解的成因，指出有机污染物的生物利用度是影响降解效果的关键因素，污泥微生物细胞壁和有机污染物结构的稳定性阻碍了有机污染物与微生物的充分接触，从而影响了生物降解速率。为此，分析了热解法、超声法、臭氧法和添加外源物4种辅助手段的作用及其强化降解的效果。通过归纳总结，明确了污泥有机污染物降解的工艺组合及其过程优化的方向。     

一种表面活性剂对活性污泥的影响及其可生物降解性的测试方法

以月桂醇聚醚硫酸酯钠(AES)、月桂醇聚醚硫酸酯铵(AESA)为例：通过污泥耗氧速率的变化了解表面活性剂对活性污泥的抑制情况；用磁力搅拌表面曝气法代替震荡培养法测试了城镇污水处理厂的活性污泥对表面活性剂的生物降解能力；用污泥负荷表征表面活性剂的初级生物降解速率，便于计算用活性污泥法处理表面活性剂至其起泡性能消失所需的时间。实验结果表明，AES、AESA浓度≥200 mg·L^-1时对活性污泥中部分微生物有抑制作用。当AES、AESA浓度≤100 mg·L^-1时，用城镇污水处理厂的活性污泥好氧处理的初级生物降解速率分别为0.06 kg AES.(kg MLSS·d)^-1、0.06 kg AESA.(kg MLSS·d)^-1；用活性污泥法好氧处理20小时后的COD_Cr去除率分别为75.7%、79.9%;AESA的可生物降解性优于AES。     

改进间歇反应器法评价废水好氧可生化性的研究

研究改进的间歇反应器(FBR)法评价废水好氧可生化性的可行性及应用范围。结果表明:改进的FBR法可单独地评价一种废水的好氧可生化性,不受污泥特性的影响。而对于评价不同废水的好氧可生化性,就必须在相同的试验条件下进行。试验证明改进的FBR法是评价废水好氧可生化性的一种新型、快速、有效的方法。     

Fate of Triton X-100 Applications on Water and Soil Environments: A Review

Triton X-100 applications as surfactant raises concern on water and soil environment due to its non-biodegradability and inhibition effect. This paper aims at reviewing Triton X-100 biodegradability and inhibition literature. It shows Triton X-100 is biodegradable by aerobic and anaerobic municipal wastewater sludge and Vibrio cyclitrophicus-sp-Nov organism. Adsorption and biodegradation are mechanisms of Triton removal. Triton inhibits anaerobic sludge organisms and some single aerobic organisms. Inhibition mechanisms are substrate shortage, physiological membrane-damaging and/or alteration in organism cell membrane. Thus Triton X-100 fate in the environment and its sustainable application can be controlled via proper selection of organism type, Triton concentration, and substrate.     

邻苯二甲酸酯类化合物生物降解的电性拓扑研究

计算了9种邻苯二甲酸酯的两类拓扑指数值:(1)基于原子类型特征的电性拓扑状态指数(En);(2)自分子拓扑图的邻接矩阵衍生的分子连接性指数(mXtv).这些拓扑指数被用于关联9种邻苯二甲酸酯的生物降解速率常数(Kb)及其半衰期(lnt1/2),经向后逐步回归与偏最小二乘法,建立了定量结构-生物降解相关(QSBR)模型,其四元最佳方程的相关系数(R2)依次为0.995、0.986.这两个方程的平均估算误差接近实验误差,并通过Jackkn ife的逐一剔除法证明有良好的可靠性与稳定性.结果表明,这些模型能够较好地解释邻苯二甲酸酯的生物降解性的递变规律.     

Builder performance in detergent formulations and biodegradability of partially dicarboxylated amylopectin

Amylopectin was partially dicarboxylated so as to retain the unreacted glucopyranose groups as biodegradable segments in the polymer chain; and the bioenzymatic degradability, as well as builder performance in detergent formulations, was evaluated and compared with data obtained from amylose. Dicarboxylation of amylopectin was carried out by conversion of the vicinal diols of the glucopyranose groups of amylopectin into the corresponding dicarboxylatesvia dialdehydes. The aerobic biodegradability of sodium dicarboxyamylopectin (DCAp) was evaluated by measuring the biological oxygen demand (BOD) with activated sludge. The biodegradability, of DCAp depended on the content of unreacted glucopyranose groups in the polymer chain. DCAp containing more than 80 mol% glucopyranose groups showed excellent biodegradability. The biodegradability, obtained by the BOD test, and the enzymatic degradability also correlated well, suggesting that these polymers are first cleaved at the unreacted glucopyranose units with subsequent assimilation of the resultant oligomeric fractions. DCAp, which was biodegradable under aerobic conditions, also biodegraded under anaerobic conditions. Detergency tests were carried out with heavy-duty detergent formulations. The detergency was determined by the content of dicarboxylate groups in the polymer when compared on an equal weight basis. The polymers with high dicarboxylate contents showed better builder performance. DCAp showed better builder performance than the corresponding amylose derivatives. This excellent builder performance is ascribed to the cluster-type structure of amylopectin, in which calcium ion is effectively sequestered. Builder performance in detergent formulation improved greatly with increasing amounts of DCAp used in the detergent formulation.     

活性艳蓝经多相类芬顿预处理前后对厌氧污泥性能的影响

以蒽醌类染料活性艳蓝为目标污染物,探讨了其对产甲烷菌的抑制机理;分析了其经多相类芬顿预处理前后对厌氧污泥EPS、粒径分布、金属离子含量的影响;同时对活性艳蓝的降解途径进行了探究。结果表明,活性艳蓝对产甲烷菌具有代谢毒性甚至生理性毒性;其进入厌氧反应器后,会造成COD去除率降低;颗粒污泥粒径减少,污泥中钙、镁离子浓度分别由40.5和16.2 mg·L^-1降低到22.5和6.8 mg·L^-1,污泥的稳定性与絮凝性变差。而经多相类芬顿预处理后,COD去除率可达90%以上,厌氧颗粒污泥EPS总量、蛋白质含量、多糖含量分别增大到98.7、69.9和28.8 mg·(g VSS)^-1,为保持颗粒污泥的活性与稳定性提供了保障。多相类芬顿体系所产生的羟基自由基首先攻击活性艳蓝的三嗪基团及不饱和共轭键的蒽醌结构,继而生成邻苯二甲酸、苯甲酸,再被降解为丁酸、草酸、乙酸等小分子羧酸,从而降低了其毒性,有利于后续厌氧生物处理的进行。     

Biogas Production of Ozone and/or Microwave-Pretreated Canned Maize Production Sludge

The production of canned maize is accompanied by formation of large volumes of waste water, with high contents of starch, and high chemical- and biochemical oxygen demand. In our work the effects of acidic, microwave and ozone pretreatment on the biogas production and aerobic biodegradability of canned maize production sludge were examined and the energy balance of the processes were determined when different sludge pretreatments were used. It was found that ozone treatment decreased the chemical oxygen demand, while the biochemical oxygen demand and the aerobic biodegradability increased. The combination of microwave and ozone treatment increased the biodegradability relative to ozone treatment alone.     

Sugar fatty acid ester surfactants: Structure and ultimate aerobic biodegradability

Ultimate aerobic biodegradabilities of an array of sugar ester surfactants were determined by International Standards Organisation method 7827, “Water Quality—Evaluation in an Aqueous Medium of the Aerobic Biodegradability of Organic Compounds, Method by Dissolved Organic Carbon” (1984). The surfactants were nonionic sugar esters with different-sized sugar head groups (formed from glucose, sucrose, or raffinose) and different lengths and numbers of alkyl chains [formed from lauric (C₁₂) or palmitic (C₁₆) acid]. Analogous anionic sugar ester surfactants, formed by attaching an α-sulfonyl group adjacent to the ester bond, and sugar esters with α-alkyl substituents were also studied. It was found that variations in sugar head group size or in alkyl chain length and number do not significantly affect biodegradability. In contrast, the biodegradation rate of sugar esters with α-sulfonyl or α-alkyl groups, although sufficient for them to be classified as readily biodegradable, was dramatically reduced compared to that of the unsubstituted sugar esters. An understanding of the relationship between structure and biodegradability provided by the results of this study will aid the targeted design of readily biodegradable sugar ester surfactants for use in consumer products.     

污泥吸附性能的研究

以处理城市污水的好氧污泥和厌氧污泥为对象，考察污泥浓度、吸附时间、温度和进水水质对污泥吸附性能的影响。研究表明：增加污泥浓度和进水有机物浓度有利于提高好氧和厌氧污泥的吸附性能：温度增加时，好氧污泥和厌氧污泥的吸附性能下降；好氧污泥和厌氧污泥对污水中有机物的吸附在15min基本达到平衡：在相同的试验条件下，好氧污泥的吸附性能强于厌氧污泥。     

Flexural modulus and molecular motion of PPE and PC by blending low molecular weight compounds

Physical and dynamic viscoelastic properties of the blends of polyphenylene-ether (PPE) and aromatic low molecular weight compounds with specific chemical structure were studied. As a result, flexural modulus increase was observed by blending aromatic phosphates, phthalic esters, or aromatic amine, which had similar chemical structure to aromatic phosphates. The observed maximum flexural modulus was 2.94 MPa, whereas PPE alone showed 2.45 MPa. There was a trend that flexural modulus increased according to the molecular weight of aromatic phosphate, though molecular weight dependence was very small for phthalic esters. By calculating the interaction between PPE chains and low molecular weight components using a molecular dynamic simulation program, it was found that there was a peculiar conformation where benzene rings interacted with methyl groups of PPE, then flexural modulus was affected as a result of this interaction. A similar conclusion was obtained by a β-dispersion shift observed by dynamic viscoelastic spectroscopy. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 19–28, 1997     

Microaerophilic biodegradation of tallow-based anionic detergents in river water

Nine anionic detergents from five general classes (alcohol sulfates, ether alcohol sulfates, sulfated alkanolamides, α-sulfo esters and alkylbenzenesul-fonates) were rapidly screened for biodegradability under aerobic and microaerophilic conditions in river water at 25 and 35 C. In decreasing order, the ease of biodegradation under microaerophilic conditions at 35 C was as follows: alcohol sulfates, sulfated alkanolamides, α-sulfo fatty acid esters and ether alcohol sulfates. Linear alkylbenzenesulfonate did not degrade. Presented at the AOCS Meeting, New Orleans, April 1970.