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。     

典型水环境因素对聚酯微塑料沉降的影响机制研究

以聚酯（聚对苯二甲酸乙二醇酯,简称PET）微塑料为主要对象,研究电解质浓度,电解质类型及pH值等典型水环境因素对其沉降行为的影响机制.结果表明：水环境中PET微塑料的沉降随电解质浓度的升高而不断增强,其悬液标准化浓度（C/C₀）最低可降至0.64;同一类型电解质对水环境中PET微塑料沉降行为的影响程度相似,而与1-1型电解质（NaCl及KCl）相比,水环境中1-2型电解质（CaCl₂及MgCl₂）的存在能够显著促进PET微塑料的沉降;水环境中PET微塑料的沉降随pH值的增加而降低,随着pH值由10降至4,PET微塑料悬液的C/C₀由最高0.98下降至最高0.76.一阶动力学沉降模型能够较好的拟合水环境中PET微塑料的沉降行为.此外,DLVO （Derjaguin-Landau-Verwey-Overbeek）理论能够反映出PET微塑料沉降行为的变化趋势,其计算结果与实验结果吻合度较高.本研究结果有助于提高对微塑料环境行为的认识程度,同时能够为评估微塑料环境风险提供理论依据.     

壳聚糖改性铝污泥对铜绿微囊藻的絮凝去除

采用给水厂副产物铝污泥代替黏土作为下沉载体,利用壳聚糖改性,将其用于铜绿微囊藻的絮凝去除.结果表明,壳聚糖与铝污泥以1：50的质量比复合改性后除藻效果明显提高：对于藻密度约为4.88×10⁶cells/mL的含藻水,当改性铝污泥最佳投加量为0.25g/L,30min后藻密度和浊度去除率分别达到100%和98.92%,形成的絮体完整紧实,分形维数值为1.719.通过Zeta电位、SEM等表征分析,此过程主要依靠壳聚糖、铝污泥及藻类之间的"电性中和"与"吸附架桥"等的作用,混凝絮凝过程快速高效且投加量小,最佳环境pH值介于7~9.5,外加NaCl、CaCl₂在离子强度较低情况下基本不影响絮凝沉淀过程.加之铝污泥对水体中的磷具有良好的吸附作用,因此壳聚糖改性铝污泥对淡水水体中铜绿微囊藻的去除及生长抑制具有良好的效果,实现了"以废治污".     

Effects of alkalinity on interaction between EPS and hydroxy-aluminum with different speciation in wastewater sludge conditioning with aluminum based inorganic polymer flocculant

Extracellular polymeric substances (EPS) form a stable gel-like structure to combine with water molecules through steric hindrance, making the mechanical dewatering of wastewater sludge considerably difficult. Coagulation/flocculation has been widely applied in improving the sludge dewatering performance, while sludge properties (organic fraction and solution chemistry conditions) are highly changeable and have important effects on sludge flocculation process. In this work, the alkalinity effects on sludge conditioning with hydroxy-aluminum were comprehensively investigated, and the interaction mechanisms between EPS and hydroxy-aluminum with different speciation were unraveled. The results showed that the effectiveness of hydroxy-aluminum conditioning gradually deteriorated with increase in alkalinity. Meanwhile, the polymeric hydroxy-aluminum (Al₁₃) and highly polymerized hydroxy-aluminum (Al₃₀) were hydrolysed and converted into amorphous aluminum hydroxide (Al(OH)₃), which changed the flocculation mechanism from charge neutralization and complexing adsorption to hydrogen bond interaction. Additionally, both Al₁₃ and Al₃₀ showed higher binding capacity for proteins and polysaccharides in EPS than monomeric aluminum and Al(OH)₃. Al₁₃ and Al₃₀ coagulation changed the secondary structure of proteins in EPS, which caused a gelation reaction to increase molecular hydrophobicity of proteins and consequently sludge dewaterability. This study provided a guidance for optimizing the hydroxy-aluminum flocculation conditioning of sludge with high solution alkalinity.     

一种浮游植物快速浓缩及固定方法的可靠性分析

为验证一种浮游植物快速浓缩固定方法——滤膜浓缩法的可靠性,采用“鲁戈氏液固定沉降法”和“滤膜浓缩法”同时鉴定了不同浮游植物浓度梯度水样,并进行了对比分析,结果表明：鲁戈氏液固定沉降法与滤膜浓缩法整体上均鉴定出7门,32属,但不同梯度上滤膜浓缩法鉴定出的浮游植物种类较多.两种方法门水平上除裸藻门（P<0.05）外丰度均无明显差异（P>0.05）,属水平上相对丰度99%以内的浮游植物均无明显差异（P>0.05）,即无论是门还是属水平上,滤膜浓缩法对浮游植物丰度的鉴定是可行的.采用两种方法得到的不同梯度下藻密度拟合方程斜率差异较小（P>0.05）且相关性显著（R²=0.958,P<0.01）,但滤膜浓缩法鉴定出的浮游植物细胞密度更大.整体来看,滤膜浓缩法得到的藻类鉴定结果与鲁戈氏液固定沉降法基本一致.     

絮凝沉降法处理含油废水的絮凝优化复配研究

气浮法是含油废水处理的常用方法,但该法工艺复杂,操作要求高.乌鲁木齐铁路局哈密机务段用气浮法处理含油废水,使用的聚合氯化铝-聚丙烯酰胺絮凝剂配方的效率及安全性欠佳,为此提出了用聚乙烯亚胺-活化硅酸-可溶性淀粉3种絮凝剂复配投加的絮凝沉降法.研究表明,本法可使废水中油的去除率达到93.9%,COD去除率达82.2%,浊度去除率达92.3%,具有去除效率高、无毒安全和处理成本低的优点,有望取代原有方法及药剂配方,具有推广应用价值.