PAC-MBR组合工艺在水处理中的应用研究现状

膜生物反应器(MBR)技术目前已在水处理领域得以广泛的研究和大规模的应用,为了进一步扩大该技术的应用领域并有效的控制其膜污染问题,粉末活性炭-膜生物反应器(PAC-MBR)组合工艺成为MBR技术领域的研究热点之一.在介绍PAC-MBR组合工艺原理的基础上,详细论述了投加PAC对该工艺的关键运行参数和膜污染的影响,以及该组合工艺在水处理领域中的应用现状,并展望了该技术的研究及应用前景.     

粉末活性炭-超滤对城市污水深度处理的试验研究

采用粉末活性炭(PAC)-超滤(UF)的组合工艺对城市二级生化处理出水进行深度处理.研究了粉末活性炭的投加对主要污染物的去除效果和对膜渗透性能的影响.结果表明,UF本身具有良好的截留SS功能和除菌作用.投加PAC对CODcr、BOD5和色度的去除率分别为55.3%,35%和69.7%.同时投加粉末活性炭能有效地提高膜通量,通过反冲洗,膜通量能得到很好的恢复.     

粉末活性炭导入超滤系统去除水中天然有机物的性能研究

通过对比研究单独超滤系统和粉末活性炭导入超滤膜系统(PAC leading-in UF)发现,投加PAC后通量下降趋势有所减缓,但并不能显著地减缓膜污染并获得高通量,说明PAC吸附的溶解性小分子有机物不是造成膜污染的主要因素,而是在膜表面形成了"次级膜".试验中发现导入系统可显著提高对天然水中腐殖酸的去除效果,去除率可达到94%.此外在导入系统投加钙盐后可明显改善膜污染,达到有效控制膜通量的下降趋势的目的.     

粉末活性炭-超滤膜联用去除水体藻类

针对日益严重的水体藻类污染问题,分别选用粉末活性炭(PAC)、超滤(UF)及其组合工艺对富藻水体藻类物质(铜绿微囊藻)去除特性进行研究.实验结果表明,单独的粉末活性炭工艺即使在高投加量情况下(PAC投加量为120 mg/L)对藻类物质去除效果不佳;单独的超滤膜工艺虽然对藻类物质有较好的去除效果(去除率达到95％),但是...     

MBR城市污水处理工艺中化学除磷的研究与应用

为考察化学除磷对膜生物反应器(MBR)工艺的影响,研究了MBR城市污水处理工艺的化学除磷.结果表明:在MBR工艺中,硫酸亚铁是适宜的化学除磷药剂.膜分离对出水总磷的截留有重要贡献,在MBR工艺中实施化学除磷比传统活性污泥法节省加药量.在处理实际城市污水的MBR工程中进行了一年以上的硫酸亚铁连续投加试验,出水总磷浓度为(0.17±0.08)mg/L,平均总磷去除率达95.0%,跨膜压差维持在15kPa以下,药剂投加费用约为0.01元/m3.在MBR工艺中投加硫酸亚铁进行化学除磷,不仅可以取得很好的除磷效果,对膜污染控制也不会造成明显的影响,而且经济可行.     

基于人工神经网络的MBR膜污染研究现状

膜生物反应器(MBR)是膜分离技术与生物处理技术相结合的一种新型、高效的污水处理技术,当前膜污染已成为限制MBR工艺推广应用的主要问题.分析了当前MBR膜污染规律的研究现状,指出了现有研究的不足,明确了人工神经网络(ANN)方法运用于MBR膜污染规律研究的优势.对ANN模型在MBR膜污染研究中的应用案例进行系统梳理,阐明了该方法在MBR膜污染研究领域的发展方向,为ANN模型在MBR膜污染研究领域的应用提供依据和参考.     

颗粒物质控制膜污染的增强型膜生物反应器工艺的研究

用于废水处理的膜生物反应器工艺(MBR),是指通过膜过滤实现活性污泥与产水的分离的新型生化法处理废水技术.由于MBR具有占地面积小和出水水质好的优点,膜生物反应器成功应用到废水处理中的案例正在迅速增加.膜污染是MBR废水处理工艺面临的主要问题之一.膜污染会导致膜的渗透性能降低,为此必须通过化学清洗才能恢复膜的性能.为了实现无化学清洗的MBR工艺,研究使用持续物理冲刷去除膜污染层的方法.在活性污泥中加入颗粒物质(粉料),通过这些颗粒物质的持续冲刷作用实现去除膜污染层的目的.经过8个多月的实验,膜组件的渗透性能保持不变,通量可以达到40 L/(m2.h)以上.系统安装了在线的浊度仪作为产水质量的检测,在试验过程中,浊度始终没有变化.作为对比,同时也进行了一个参照实验(MBR标准工艺,没有加入颗粒物质),实验结果表明,传统的MBR工艺的膜组件渗透性能会不断下降导致通量下降,需要进行化学清洗.新型MBR工艺高通量和无需化学清洗的优势,将极大地提高MBR工艺的成本效益.     

MBR膜污染的形成及其影响因素研究进展

拥有众多优势的膜生物反应器(MBR)技术在污废水处理方面有着广阔的应用前景,膜污染一直是MBR技术应用研究的热点和难点.膜污染的形成和主要污染因素的探讨为MBR膜污染研究奠定了基础,而确定操作工艺条件和膜特性对膜污染的影响规律,可为MBR系统设计或运行中减缓和控制膜污染提供指导.本文概述MBR膜污染的形成过程、主要污染因素及操作参数和膜性能对膜污染的影响.     

钢铁废水超滤工艺优化现场试验研究

在钢铁工业废水回用深度处理装置上,内压式中空纤维超滤膜HYDRAcap60系统被用于反渗透预处理.介绍了针对膜污染问题开展的工艺优化现场试验,给出了优化工艺条件.分析了膜污染物的成分,并讨论了膜污染的可能机理.在超滤膜前在线投加粉末活性炭-三氯化铁混合絮凝剂对促进系统稳定运行效果明显,有效解决了膜污染的发生.现场试验分为条件试验和优化工艺确认试验,确认试验连续运行近3个月,期间试验装置跨膜压差没有明显增加.酸性和碱性溶液化学清洗(CIP)和加药反洗(CEB)对系统性能恢复都有明显作用,透过膜的清洗液循环非常重要.     

颗粒悬浮填料复合式膜生物反应器的过滤性能研究

介绍了颗粒填料复合式膜生物反应器(HMBR)在工业废水处理中的应用.在运行条件一致的情况下,对普通膜生物反应器(MBR)和颗粒填料复合式膜生物反应器(HMBR)进行了对比实验,着重研究了颗粒填料在膜污染控制方面的作用.结果表明:由于投加填料颗粒,HMBR的沉积层阻力减少了86%,临界通量增长了约20%;在长期运行过程中MBR的膜污染速率是HMBR的3.3倍.在膜生物反应器中投加颗粒填料可以有效地改善其过滤性能,减缓膜通量的下降.     

Enhanced performance of a submerged membrane bioreactor with powdered activated carbon addition for municipal secondary effluent treatment

The aim of this study was to investigate the feasibility of PAC-MBR process treating municipal secondary effluent. Two laboratory-scale submerged MBRs (SMBR) with and without PAC addition were continuously operated in parallel for secondary effluent treatment. Approximately 63%TOC, 95% NH₄⁺-N and 98% turbidity in secondary effluent were removed by the PAC-MBR process. Most organics in the secondary effluent were found to be low molecular weight (MW) substances, which could be retained in the reactor and then removed to some extent by using PAC-MBR process. Parallel experiments showed that the addition of PAC significantly increased organic removal and responsible for the largest fraction of organic removal. Membrane fouling analysis showed the enhanced membrane performance in terms of sustainable operational time and filtration resistances by PAC addition. Based on these results, the PAC-MBR process was considered as an attractive option for the reduction of pollutants in secondary effluent.     

Effect of PAC addition on immersed ultrafiltration for the treatment of algal-rich water

The aim of this study was to evaluate the effect of powdered activated carbon (PAC) addition on the treatment of algal-rich water by immersed ultrafiltration (UF), in terms of permeate quality and membrane fouling. Experiments were performed with a hollow-fiber polyvinyl chloride ultrafiltration membrane at a laboratory scale, 20-25°C and 10 L/(m(2) h) constant permeate flux. UF could achieve an absolute removal of Microcystis aeruginosa cells, but a poor removal of algogenic organic matter (AOM) released into water, contaminants responsible for severe membrane fouling. The addition of 4 g/L PAC to the immersed UF reactor significantly alleviated the development of trans-membrane pressure and enhanced the removal of dissovled organic carbon (by 10.9±1.7%), UV(254) (by 27.1±1.7%), and microcystins (expressed as MC-LR(eq), by 40.8±4.2%). However, PAC had little effect on the rejection of hydrophilic high molecular weight AOM such as carbohydrates and proteins. It was also identified that PAC reduced the concentrations of carbohydrates and proteins in the reactor due to decreased light intensity, as well as the MC-LR(eq) concentration by PAC adsorption.     

TiO_2动态改性膜应用于MBR的研究

采用二氧化钛(TiO_2)纳米粒子对聚偏氟乙烯中空纤维膜微滤膜(PVDF MF,0.1μm)和实验室自制聚砜中空纤维膜超滤膜(PSF UF,0.05μm)进行表面亲水改性,以期提高膜的抗污染能力.采用膜接触角、纯水通量、出水TOC、膜压差和扫描电子显微镜(SEM)进行表征了TiO_2动态膜的性能.将TiO_2纳米颗粒改性后的PVDF MF和PSF UF膜应用于膜生物反应器(MBR)处理模拟焦化废水(TOC=500 mg/L),考察了其对MBR过滤性能的影响.实验结果表明,改性后膜的水接触角明显减小,亲水性增强,TMP升高速率明显降低,模拟焦化废水,TOC的去除率平均可达95%,经返洗及次氯酸钠清洗后膜表面TiO_2层外观没有明显变化.改性后的膜组件较显著地增加了MBR的膜抗污染的优势,且具有一定的稳定性.因此,将TiO_2动态改性耐污染膜应用于MBR是可行的.     

Evaluation of potential integration of entrapped mixed microbial cell and membrane bioreactor processes for biological wastewater treatment/reuse

The challenge of biological wastewater treatment process is the design and operation of effective retention of mixed microbial cells within the reactor. Entrapped mixed microbial cell (EMMC) technology is designed to entrap the mixed microbial cells in polymeric carriers; membrane bioreactor (MBR) process utilizes membrane sheets/fibers to effectively retain the biomass in the reactor. These two biotechnologies are considered potential alternatives for conventional biological treatment/reuse because of their capability of retaining high concentration of biomass in the reactor, or in other words increasing the solid retention time (SRT). The simultaneous removal of organics and nitrogen were investigated using a modified EMMC system design. The modified EMMC system demonstrated higher organic and nitrogen removal performance due to high SRT. Compared to single-stage MBR process operated at similar conditions, the modified EMMC system was able to achieve slightly lower organic removal, comparable nitrification, and higher total nitrogen removal. One limitation in applying an EMMC only treatment process regime for potential reuse of treated wastewater is that such an operation requires the removal of pathogens and large particles if disinfection and solid/liquid separation were not followed. The major challenge of MBR process to overcome is membrane fouling, and the high energy consumption associated with fouling control. The intrinsic features of EMMC process including high SRT, low, and stabilized effluent suspended biomass concentration may significantly reduce the chance and extent of membrane fouling; while the membrane filtration can further polish the effluent quality from EMMC process. Therefore, integrating MBR and EMMC is strongly recommended because it may be a ??break-through?? for solving the membrane fouling problem and in improving effluent quality for potential reuse.     

Performance enhancement with powdered activated carbon (PAC) addition in a membrane bioreactor (MBR) treating distillery effluent

This work investigated the effect of powdered activated carbon (PAC) addition on the operation of a membrane bioreactor (MBR) treating sugarcane molasses based distillery wastewater (spentwash). The 8 L reactor was equipped with a submerged 30 μm nylon mesh filter with 0.05 m² filtration area. Detailed characterization of the commercial wood charcoal based PAC was performed before using it in the MBR. The MBR was operated over 200 days at organic loading rates (OLRs) varying from 4.2 to 6.9 kg m⁻³ d⁻¹. PAC addition controlled the reactor foaming during start up and enhanced the critical flux by around 23%; it also prolonged the duration between filter cleaning. Operation at higher loading rates was possible and for a given OLR, the chemical oxygen demand (COD) removal was higher with PAC addition. However, biodegradation in the reactor was limited and the high molecular weight compounds were not affected by PAC supplementation. The functional groups on PAC appear to interact with the polysaccharide portion of the sludge, which may reduce its propensity to interact with the nylon mesh.     

膜-生物反应器的研究及其在废水处理中的应用

综述了废水处理领域中的膜-生物反应器的基本特点、应用现状、存在的问题以及国内外研究的进展；重点阐述了膜-生物反应器运行工艺、新型膜材料与器件以及影响膜污染形成的因素与防治措施；并对今后的研究方向进行了展望．