Integration of biological method and membrane technology in treating palm oil mill effluent

Palm oil industry is the most important agro-industry in Malaysia, but its by-product-palm oil mill effluent (POME), posed a great threat to water environment. In the past decades, several treatment and disposal methods have been proposed and investigated to solve this problem. A two-stage pilot-scale plant was designed and constructed for POME treatment. Anaerobic digestion and aerobic biodegradation constituted the first biological stage, while ultrafiltration (UF) and reverse osmosis (RO) membrane units were combined as the second membrane separation stage. In the anaerobic expanded granular sludge bed (EGSB) reactor, about 43% organic matter in POME was converted into biogas, and COD reduction efficiency reached 93% and 22% in EGSB and the following aerobic reactor, respectively. With the treatment in the first biological stage, suspended solids and oil also decreased to a low degree. All these alleviated the membrane fouling and prolonged the membrane life. In the membrane process unit, almost all the suspended solids were captured by UF membranes, while RO membrane excluded most of the dissolved solids or inorganic salts from RO permeate. After the whole treatment processes, organic matter in POME expressed by BOD and COD was removed almost thoroughly. Suspended solids and color were not detectable in RO permeate any more, and mineral elements only existed in trace amount (except for K and Na). The high-quality effluent was crystal clear and could be used as the boiler feed water.     

滨海生态景观河道对污水处理厂出水净化效果研究

为了探讨天津滨海泰达生态景观河道对污水处理厂出水深度净化的效果,2009年对该河道水体进行监测分析,结果表明该河道对氮、磷营养盐具有良好的可持续净化能力,河道出水达到景观环境用水的再生水水质标准,出水TN、NH3-N、TP和PO43-平均浓度分别为1.49mg/L、0.75mg/L、0.16mg/L和0.01mg/L,相应去除率分别达到93.38%、41.13%、88.09%和98.16%;沿程水体COD和TDS变化规律不明显,去除效果不理想;河道中端与出水端水体水质相近,建议在今后相似工程中可以适当提高河道式湿地的水力负荷。     

Dissolved organic matter removal using magnetic anion exchange resin treatment on biological effluent of textile dyeing wastewater

This study investigated the removal of dissolved organic matter（DOM） from real dyeing bio-treatment effluents（DBEs） with the use of a novel magnetic anion exchange resin（NDMP）.DOMs in two typical DBEs were fractionized using DAX-8/XAD-4 resin and ultrafiltration membranes. The hydrophilic fractions and the low molecular weight（MW）（〈3 kDa） DOM fractions constituted a major portion（〉50%） of DOMs for the two effluents. The hydrophilic and low MW fractions of both effluents were the greatest contributors of specific UV254absorbance（SUVA254）,and the SUVA254 of DOM fractions decreased with hydrophobicity and MW. Two DBEs exhibited acute and chronic biotoxicities. Both acute and chronic toxicities of DOM fractions increased linearly with the increase of SUVA254 value. Kinetics of dissolved organic carbon（DOC） removal via NDMP treatment was performed by comparing it with that of particle active carbon（PAC）. Results indicated that the removal of DOC from DBEs via NDMP was 60%,whereas DOC removals by PAC were lower than 15%. Acidic organics could be significantly removed with the use of NDMP. DOM with large MW in DBE could be removed significantly by using the same means. Removal efficiency of NDMP for DOM decreased with the decrease of MW. Compared with PAC,NDMP could significantly reduce the acute and chronic bio-toxicities of DBEs. NaCl/NaOH mixture regenerants,with selected concentrations of 10% NaCl（m/m）/1%NaOH（m/m）,could improve desorption efficiency.     

化学机械浆废水处理技术探讨

简要分析了化学机械法制浆废水的特点，对适用于处理化学机械法制浆废水的常用处理方法，如好氧、厌氧生物处理法、特定微生物处理技术、臭氧氧化法以及膜分离技术等在国内外的应用研究情况做了比较分析。     

DNBF-O3-GAC组合工艺深度脱除氮磷及代谢产物

为提高污水厂尾水水质,本研究采用新型缓释碳源复配海绵铁、活性炭作为反硝化生物滤池的复合填料,分别以模拟二级处理出水和实际污水厂尾水为进水,考察了复合缓释碳源填料反硝化生物滤池-臭氧-活性炭(DNBF-O_3-GAC)组合工艺同步脱氮除磷及去除微生物代谢产物的性能,并借助Mi Seq高通量测序技术分析了反硝化生物滤池生物膜中的微生物群落结构特征.结果表明,组合工艺取得了较好的脱氮除磷及微生物代谢产物的效果:模拟配水阶段和实际尾水阶段NO_3~--N平均去除率分别达到88.87%、79.99%;TP平均去除率分别达到87.67%、65.51%;UV254平均去除率分别达到45.51%、49.23%.组合工艺各处理单元具有不同的功能:NO_3~--N、TN、TP、TFe的变化主要发生在反硝化生物滤池反应器中;UV254、三维荧光强度的变化主要发生在臭氧-活性炭反应器中.微生物在属水平进行聚类分析结果表明,反硝化脱氮系统存在硫自养反硝化菌和异养反硝化菌,当实际尾水阶段碳源相对不足时,硫自养反硝化作用有了显著加强,Thiobacillus(硫杆菌属)的占比由7.44%上升至29.62%,硫自养反硝化与异养反硝化形成的这种互补作用延长了新型缓释碳源的使用周期.     

DEEP WELL DISPOSAL OF SECONDARY EFFLUENT IN DADE COUNTY,FLORIDA1

ABSTRACT: Data were obtained from drilling and testing of a test injection well for deep underground injection of waste water effluent from the proposed 50-million-gallon-per-day (mgd) South District Regional Wastewater Treatment Plant of the Miami-Dade Water and Sewer Authority, Dade County, Florida. The drilling operation progressed in stages, each stage coverting the strata to be sealed off by the 48-inch, 40-inch, 30-inch, and 20-inch casings, respectively. Total depth of the well is 3,200 feet. The top of the saline, cavernous, dolomitic Boulder Zone was found at 2,790 feet below the surface and is separated from the Floridan aquifer above by approximately 1,100 feet of confining limestone layers. These confining layers were determined, by packer testing, to be very effective. The transmissivity of the Boulder Zone was estimated to be 14 × 10⁶ gallons per day per foot (gpd/ft) from the data obtained from pump out tests. An 8,000-gallon-per-minute (gpm) injection test was conducted to confirm well performance under operating conditions. Based on all of the data obtained, it was concluded that underground injection into the Boulder Zone of secondary waste water effluent from the proposed treatment plant is feasible, both hydraulically and environmentally. A monitoring system was proposed to provide a record of the effects of injection on the subsurface environment.     

UV/H2 O2法对印染废水生化出水中不同种类有机物的去除效果

采用UV/H2O2高级氧化法对印染废水生化出水的处理进行研究,探讨了不同反应时间、H2O2投加量、反应初始pH值等因素对UV254,ADMI7.6、DOC和COD去除效果的影响.结果表明,以UV254、ADMI7.6、DOC和COD的去除率为筛选依据,确定出最佳参数组合为:反应初始pH值为原水pH 7.4～8.1,H2O2投加量为4.5 mmol.L-1,紫外光照射时间为50 min,在最佳处理条件下,UV254、ADMI7.6、DOC和COD的去除率分别达到77%、94%、40%和69%.通过XAD-8/XAD-4吸附树脂联用技术将印染废水生化出水中溶解性有机物分为疏水酸、非酸疏水物质、弱疏水物质及亲水物质4类有机物,研究了UV/H2O2氧化工艺对生化出水中各种有机物及色度的去除效果.实验结果表明,对于该印染废水的生化出水,疏水性物质是引起色度的主要物质,所占比例以ADMI7.6表征时为92%,其中以非酸疏水物质的贡献最大,达到53%.UV/H2O2高级氧化法处理此水样中的弱疏水性有机物、疏水酸和非酸疏水物质均有较好的处理效果,对亲水性有机物的处理效果较差.实验表明,相对分子质量>10 000的大分子有机物对DOC和ADMI7.6的去除贡献较大,对UV254的去除贡献接近一半.     

好氧与电絮凝组合工艺处理糖蜜酒精厌氧出水研究

采用好氧与电絮凝联合工艺处理糖蜜酒精厌氧出水,考察COD和色度的去除效果.首先,采用SBR工艺去除废水中的易降解污染物.结果表明:采用SBR法处理稀释10倍的糖蜜酒精厌氧出水,适宜的水力停留时间为10 h;COD去除率为42％,脱色效果不明显,BOD5/COD由0.54下降到0.09,好氧出水难以生化降解.进一步采用电絮凝法处理好氧出水,并考察了极板间距、初始pH值、电流密度和电解时间等因素对COD去除及脱色效果的影响.结果表明,在极板间距为3 cm、废水pH=7.83(无须调节,最佳pH=6～8)、电流密度为10 mA/cm2、电解时间为30 min的条件下进行电絮凝处理,与稀释10倍的糖蜜酒精厌氧出水相比,COD总去除率可达86％,脱色率达95％.     

Characteristics of microbial community involved in early biofilms formation under the influence of wastewater treatment plant effluent

Effluents from wastewater treatment plants (WWTPs) containing microorganisms and residual nutrients can influence the biofilm formation. Although the process and mechanism of bacterial biofilm formation have been well characterized, little is known about the characteristics and interaction of bacteria, archaea and eukaryotes in the early colonization, especially under the influence of WWTP effluent. The aim of this study was to characterize the important bacterial, archaeal and eukaryotic species in the early stage of biofilm formation downstream of the WWTP outlet. Water and biofilm samples were collected 24 and 48 hr after the deposition of bio-cords in the stream. Illumina Miseq sequencing of the 16S and 18S rDNA showed that, among the three domains, the bacterial biofilm community had the largest alpha and beta diversity. The early bacterial colonizers appeared to be “biofilm-specific”, with only a few dominant operational taxonomic units (OTUs) shared between the biofilm and the ambient water environment. Alpha-proteobacteria and Ciliophora tended to dominate the bacterial and eukaryotic communities, respectively, of the early biofilm already at 24 hr, whereas archaea played only a minor role during the early stage of colonization. The network analysis showed that the three domains of microbial community connected highly during the early colonization and it might be a characteristic of the microbial communities in the biofilm formation process where co-occurrence relationships could drive coexistence and diversity maintenance within the microbial communities.     

出水回流对ABR反应器启动过程中污染物去除效果和微生物种群的影响

出水回流对厌氧折流板反应器(ABR)抗酸化性能及机制的影响研究是提升高负荷ABR稳定运行研究的热点.因此,本文采用ABR处理模拟废水,采用常温、高负荷启动方式,研究回流对ABR启动过程中运行效果、挥发性脂肪酸(VFA)及微生物种群分布的影响.结果显示,回流对ABR的COD去除率影响不大,但可使反应器的pH值更稳定;回流反应器中的VFA累积速率降低了1/3,有利于减少VFA的积累;回流反应器中的微生物主要有短杆菌、球菌、链球菌及拟杆菌等,回流提高了反应器中的微生物多样性,从而提高了微生物种群的稳定性.回流反应器中真细菌、古细菌、产氢产乙酸菌和耗氢产乙酸菌的相对丰度均高于不回流反应器,真细菌平均高出8.5%,古细菌平均高出4.5%,产氢产乙酸菌和耗氢产乙酸菌分别高出3.5%和3.0%.通过回流能够调控pH值、VFA浓度、微生物种群结构及分布,进而提升ABR反应器的抗酸化性.