分散絮凝法去除废水中邻氯苯酚的试验研究

采用表面活性剂(吐温-20和0.5%的十二烷基苯磺酸钠溶液)作分散剂、三氯化铁作絮凝剂,对废水中邻氯苯酚的去除进行了试验研究,探讨了絮凝pH值、分散剂用量及絮凝剂用量等因素对处理效果的影响.试验结果表明:在最佳条件下,处理质量分数为1.0%的邻氯苯酚废水去除率可达88.6%;加入分散剂,可有效提高三氯化铁絮凝剂对邻氯苯酚的去除率.     

锥形流化床混凝工艺混凝反应特征和机制初探

研究了以锥形流化床作为混凝装置时混凝反应的控制因素,以及该工艺的混凝效率和形成絮体特征,并对该工艺的混凝机制进行了探讨.结果表明,填充颗粒性质、床高和表观流速等参数的变化会引起床内速度梯度G和反应时间T的变化.设置沉淀时间为20min,该工艺对高岭土悬浊液的混凝效率随着Camp值GT的增加呈上升趋势.G值在169.2～189.7s-1区间内时,混凝效果受反应时间的影响较敏感.但当G值低于169s-1时,过低的G值限制了颗粒的碰撞,混凝效果随反应时间的增加不再升高.分析认为,锥形流化床反应器内部颗粒的无规则运动产生涡旋和沿床高方向表观流速逐渐减小等特征使其作为混凝装置具有可行性.但在相近的G和反应时间下,与机械混凝装置相比,该锥形流化床混凝装置形成的絮体当量尺寸较大,但平均密度稍小.     

改性木质素磺酸盐絮凝处理含镍废水的研究

文章采用改性木质素磺酸盐絮凝处理含镍电镀废水,此法处理含镍废水效果明显。实验表明:当在室温条件下,单体用量为1.5mol/L,反应时间为48h时,可得到分子量较大、絮凝效果较好的改性木质素磺酸盐。用这种改性木质素磺酸盐处理含镍废水,当其用量为100mg/L,pH值控制在7,接触反应时间为70min,在室温的条件下,可使含镍废水中的Ni2+,COD的去除率分别达到98.0%和80.0%以上。     

中、小型印染企业废水处理工艺的选择

随着印染工艺和产品结构的改变,印染水质同时也发生了很大变化,印染废水的处理难度也随之加大。针对印染废水的这一特点,本文首次提出了以膜分离技术为核心印染废水闭路循环处理技术,以实现印染废水的再生利用,解决印染废水对环境的危害。膜分离技术对中、小型印染企业废水处理是比较经济适用的废水处理技术,并以某企业40m3/d印染废水处理工程为例对该工艺进行了深入的研究。     

化学混凝/倒置A^2/O工艺处理猪场废水试验研究

猪场废水是一种高浓度有机废水,里面含有大量的有机物、氮、磷、悬浮物等污染物质,直接采用传统的工艺处理很难达到排放标准。本试验采用化学混凝/倒置A2/O工艺处理猪场废水,效果较好。通过比较,发现采用FeC l3为混凝剂1 400 mg/l时对废水的絮凝效果最好,而好氧区HRT为7 h回流比为200%时对有机物及氮的去除效果最好。     

加载絮凝在水处理中的应用进展

加载絮凝是一种快速絮凝沉淀工艺,包括微砂加载絮凝和磁加载絮凝。本文叙述了加载絮凝工艺的技术特点与研究进展,加载介质可以成为絮凝体的核心,提高沉淀速度,增强沉淀性能,较常规絮凝可有效的减少沉淀池占地面积和沉淀时间,具有良好的发展前景。     

Physical characteristics of conditioned anaerobic digested sludge – A fractal, transient and dynamic rheological viewpoint

The changes in the physical characteristics of unconditioned and conditioned anaerobic digested sludge (ADS) biosolids, such as capillary suction time (CST), yield stress, average size and fractal dimensions, were investigated through a CST test, transient and dynamic rheological test and image analysis. The results showed that the optimum polymer dose range was observed when CST or its reciprocal value was employed as an indicator. There were good correlations between the yield stresses determined from both a controlled shear stress test and a strain amplitude sweep test. The yield stress and storage modulus (G′) increased as the polymer dose increased in most cases. A frequency sweep test revealed that polymer conditioning could extend the frequency sweep ranges for their elastic behaviors over viscous behaviors as well as the gel-like structure in the linear viscoelastic range. These results implied that more deformation energy was stored in this rigid structure, and that elastic behavior became increasingly dominant with the addition of the polymer in most cases. In addition, both the average sizes and two-dimensional fractal dimensions for conditioned ADS biosolids presented a similar up-climax-down variation trend as the polymer doses increased, whereas the critical polymer doses at the highest average sizes or two-dimensional fractal dimensions, were different. Correlation analysis revealed that the conditioned ADS dewaterability was not correlated with the yield stresses, while the average sizes or the two-dimensional fractal dimensions for conditioned ADS biosolids could be taken as the indication parameters for ADS dewaterability.     

丝状真菌调理对柠檬酸污泥脱水性能的影响

利用实验室分离的丝状真菌Aspergillus niger SS5对柠檬酸污泥进行了污泥脱水前的生物调理.结果表明,菌液浓度和调理时间是影响污泥脱水性能的主要因素,调理后污泥的脱水性能、沉降性能均有明显改善,调理后的污泥负电荷减少,粒径显著增大,结合水含量比未投加菌液的空白对照降低了近40%.同时,真菌调理显著降低了上清液COD及污泥各EPS层的蛋白质和多糖含量,EPS中蛋白质的降解与污泥结合水含量、D₅₀和Zeta电位显著相关,是影响柠檬酸污泥脱水性能改善的重要因素,且有机物的降解并未导致污泥pH值的显著变化,这和柠檬酸污泥拥有较大的酸碱缓冲容量有关.采用20mL/g DS的Aspergillus niger SS5调理柠檬酸污泥,调理3d可使泥饼含水率降至71.98%,且调理过程无化学药剂加入,更有利于柠檬酸等食品发酵类工业污泥的后续资源化综合利用.     

Performance evaluation on the pollution control against wet weather overflow based on on-site coagulation/flocculation in terminal drainage pipes

• A way for overflow control based on on-site coagulation/flocculation was proposed. • Coagulant and flocculant dose were optimized based on pollutant removal performance. • Settling time of 5 min is enough in a proper transmission distance. • Fast removal of particulate pollutants could be achieved under varied flow. The pollution caused by wet weather overflow in urban drainage systems is a main factor causing blackening an odorization of urban rivers. The conventional overflow treatment based on coagulation/flocculation in terminal drainage systems requires relatively large space and long retention time demand that makes it not applicable in crowded urban drainage systems or under heavy rains. On-site coagulation/flocculation in terminal drainage pipes was proposed in this study which was aimed to transfer the coagulation/flocculation process to the inside of pipes at the terminal drainage system to save space and reduce the retention time of the coagulation/flocculation process. The optimized dose of chemicals was studied first which was 80 mg/L of coagulant and 0.8 mg/L of flocculant. Settling for only 5 min can remove most of the pollutants at 406.5 m of transmission distance. In addition, the relation of wet weather overflow rate and concentration of pollution load on the on-site coagulation/flocculation process was investigated, which indicated that high removal of pollutant was gained at a large range of flow velocity and pollutant concentration. Finally, the study confirmed electric neutralization, bridging, and net capture as the major mechanisms in this process, and further optimization was proposed. The proposed process can reduce much turbidity, chemical oxygen demand, and total phosphorous, but hardly remove soluble ammonia and organics. This work provides scientific guidance to address wet weather overflow in terminal drainage pipes.     

涡漩水流对混凝沉淀效果影响的研究

应用粒子图象测速技术，建立了研究往复隔板絮凝池涡漩流场的室内测试系统，对往复隔板絮凝池拐弯处水流涡漩运动进行了研究，运用粒子图象测速技术，可进行多点同步测量，获得速度随时间变化的平面和空间分布，因该技术是非常接触式的，不干扰流场，故提高了可靠性，使用量测系统软件，对不同方案的涡漩运动进行了分析，并对混凝沉淀效果进行了比较。