Biodegradation of Plastics in Compost Prepared at Different Composting Conditions

Maximum temperature during the thermophilic phase and moisture content were controlled in the course of composting to examine the effects of these composting conditions on the quality of the compost used for the evaluation of the biodegradability of plastics. The moisture content during composting was controlled at 65%, while keeping the maximum temperature below 46°C, 58°C and 70°C, respectively. In turn, the maximum temperature was controlled to be below 58°C, while maintaining the moisture content at 45%, 55% and 65% respectively. The number of microbial cells was examined in the five compost samples thus prepared. Biodegradation of cellulose, polycaprolactone and poly(butylene succinate-co-butylene adipate) was conducted in the five compost samples, and the consistency and reproducibility of the test results were explored.     

邻苯二甲酸酯类化合物生物降解的拓扑研究

计算了9种邻苯二甲酸酯的两类拓扑指数值:一是基于原子类型特征的电性拓扑状态指数(En);二是分子拓扑图邻接矩阵衍生的分子连接性指数(mχvt).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)及半衰期的自然对数(ln t1/2),经向后逐步回归与偏最小二乘法,建立它们的定量结构─生物降解相关(QSBR)模型,其四元最佳方程的相关系数的平方(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Jackknife的逐一剔除法证明有良好的可靠性与稳健性.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.     

水解酸化工艺改善油田采出水生物降解性能

研究了水解酸化工艺改善难生物降解油田采出水的生物降解性能及其有机物去除效果．结果表明,在污泥量为25000 mg/L,HRT为8h条件下,采出水中石油类物质降低到了10 mg/L以下,挥发酚类物质降低到了未检出水平,生物降解性能得到了较大改善,其BOD_5/COD提高了17%,为后续好氧生物处理提供了良好的基质准备．工艺抗毒性和冲击负荷能力较强,出水稳定．     

微电解/厌氧法提高染料废水可生化性探索

文章以高色度与高CODcr浓度的实际染料生产废水和模拟染料废水为研究对象,采用微电解法和厌氧微生物法对废水进行处理,考察其对废水色度与CODcr的降解效果,以及对废水好氧可生化性的影响。实验结果显示,微电解法处理实际废水,对色度有比较明显的去除效果,对CODcr有一定去除率效果,并使废水的好氧可生化性明显提高;经过驯化的厌氧微生物能够破坏染料的化学结构,能够去除部分CODcr,并对废水的好氧可生化性有一定改善。     

焦化废水光催化降解研究

在0.5h和300W高压汞灯紫外光处理条件下,采用TiO2,ZnO和TiO2＋ZnO不同催化剂组合,研究了紫外光催化处理对高浓度焦化废水中CODcr及氨氮去除率的影响。结果表明TiO2是焦化废水中CODcr光降解处理的最佳催化剂;TiO2紫外光能够有效地降低高浓度废水中的CODcr,但对其中氨氮的去除较差。考虑到经济可行性和焦化废水光降解处理的工程实用性,进一步研究了典型焦化厂生化处理站进、出废水按照1L/min处理量施加TiO2紫外光照处理的效果和对废水可生化性的影响,结果表明,短时间的TiO2紫外光照处理焦化废水对降低焦化废水进、出水CODcr和NH3-N的作用十分有限,但可以显著地增加焦化废水进、出水的可生化性。因此该方法可作为焦化废水生化处理站进水预处理和出水深度处理的一项技术。     

几种氯酚的生物降解性及其对厌氧产甲烷毒性的试验研究

在35±1℃中温厌氧条件下,以葡萄糖为共基质,采用间歇试验法,研究了2,4-二氯酚、2,4,6-三氯酚、2,3,4,6-四氯酚及五氯酚的产甲烷毒性及生物降解性.试验结果表明:四种氯酚对产甲烷菌活性的抑制程度大小为:五氯酚>2,4,6-三氯酚>2,3,4,6-四氯酚>2,4-二氯酚.氯酚的去除率大小为:五氯酚>2,3,4,6-四氯酚>2,4,6-三氯酚>2,4-二氯酚.氯酚去除率与自身毒性关系不明显,但COD去除率与氯酚的毒性大小呈负相关.     

Transformation of Pectins into Non-Ionic or Anionic Surfactants Using a One-Pot and Cascade Mode Process

The present article describes the one-pot synthesis of double- and single-tailed surfactants by a cascade process that involves the hydrolysis/butanolysis of pectins into butyl galacturonate monosaccharides followed by transesterification/transacetalisation processes with fatty alcohols, and subsequent aqueous basic and acid treatments. The cascade mode allows the depolymerisation to proceed more efficiently, and the purification conditions are optimised to make the production of single-tailed surfactants more manufacturable. These products in a pure form or as mixtures with alkyl glycosides resulting from butanolysis and transglycosylation of pectin-derived hexoses, exhibit attractive surface-tension properties, especially for the n-oleyl ᴅ-galactosiduronic acid products. In addition, a readily biodegradability and an absence of aquatic ecotoxicity are shown for the galacturonic acid derivatives possessing an oleyl alkyl chain at the anomeric position.     

超声波处理VC发酵污水/污泥的研究

利用特制高功率超声波发生器对某维生素C制造厂的污水及污泥进行处理,研究超声波对难降解有机废水好氧生化降解效率及污泥减量化的影响.结果表明:特制超声波发生器对好氧接触氧化池进水进行高功率较长时间(2 860 W,5 min)超声处理,可去除56%的COD,B/C比从0.13提高到0.22;对推流式曝气池进水进行超声(2 860 W,2 min)处理,可去除33%的COD,B/C比提高一倍以上(从0.11提高到0.23);并且超声处理降低了接触氧化池之后的二沉池剩余污泥的沉降体积,促进了污泥井中混合剩余污泥中某些易被生化降解的物质由固相转移到液相,进而达到污泥减量化的目的.     

1，3-金刚烷二醇快速生物降解研究

研究1,3-金刚烷二醇在特定温度条4#-TN快速生物降解。向-定体积的已接种的无机培养基加入适量受试物1,3-金刚烷二醇（100mg／L受试物至少预留50-100mg／L的理论需氧量）作为唯-的有机碳源,密闭烧瓶后在恒温（变化小于±1℃）下连续搅拌28d．通过用仪器测定烧瓶内气体压力的变化,可得到耗氧量。释放的二氧化碳用氢氧化钾吸收。在受试物生物降解的过程中（用平行试验中的接种物空白的耗氧来校正）,微生物种群吸收氧的量以ThOD的百分率来表示,参比苯甲酸钠28d降解率为82．73％,而1,3-金刚烷二醇降解率为4．17％。判定1,3-金刚烷二醇属于不易快速生物降解物质。     

Reductive Degradation Behavior of Bioreducible Poly(disulfide amine) for Enhancing SiRNA Efficiency

Bioreducible cationic polymer poly(CBA‐DAH) containing repeated disulfide linkages on the polymer backbone was synthesized through Michael‐type polyadditions of CBA to DAH monomers. Poly(CBA‐DAH) could spontaneously form nanoscale polyelectrolyte complexes through electrostatic interactions with siRNA in an aqueous phase. These nanoparticles were rapidly degraded under the reductive cytoplasmic environment with subsequently releasing the siRNA cargo into the cytoplasm where RNAi takes place, as a result of the breakdown of disulfide bonds in the polymers. The reductive degradation behavior of the poly(CBA‐DAH)/siRNA polyplexes is more likely to increase RNAi activity with enhancing the cytoplasmic localization of siRNA molecules. Poly(CBA‐DAH) may have great potential as a gene carrier especially for therapeutic applications of siRNAs owing to the reductive degradation characteristics.