Invertebrate community characteristics in biologically active carbon filter

Biologically active carbon （BAC） system was set up in a water plant of South China during January to December 2007,to study the invertebrate community characteristics of BAC filter.Thirty-seven invertebrate species were found,of which 28 belonging to rotifers.Filter operation could lead to an output of invertebrates in high abundances with the filtrate,and the maximum density could reach 5608 individuals/m 3.Average abundances in the effluent water increased in 27-33 folds in comparison to the influent water during the sampling period.Invertebrate community succession had the following trend：filter-feeding animals → small benthic invertebrates → large benthic and resistant invertebrates.Abundances of large-sized invertebrates （copepod adult and oligochaete） at bigger-media column were significantly higher than that at small-media column.The results implied the abundant species diversity of invertebrate in BAC filter.The relationship between invertebrate and biofilm still remain to be studied in detail.

Design and Operation of the Printing and Dyeing Wastewater Treatment Project by Combination of Coagulation Sedimentation - Hydrolytic Acidification with Aeration Tank - Biological Aerated Filter - Active Sand Filter

In order to protect quality of Baiyangdian surface water and Gaoyang groundwater,the project is applied to process printing and dyeing wastewater that contains complicated compositions,high concentrations of organics and SS,and lots of pollutants difficult to degrade by microorganism. The process and operating parameters of project are optimized and debugged,and its economic and environmental benefits are analyzed.The results show that the process of coagulation sedimentation-hydrolytic acidification with aeration tank-biological aerated filter-active sand filter is applied in Gaoyang Sewage Treatment Plant. The design scale of sewage treatment plant is 120000 m^3/d. The influent is as following: COD is 669mg/L; SS is 424mg/L; NH_3-N is 8.83mg/L; TP is 6.03mg/L. After the process,the best removal rates of COD,SS,NH_3-N and TP are 93. 5%,98. 8%,97. 1% and 96. 2%,respectively. The various indexes of effluent water complied with standard A of the first order in Pollutants Emission Standard of Urban Wastewater Treatment Plant( GB 18918-2002). The processing cost is only 0. 807 yuan/m^3. As a result,the project construction and operation not only improve the environment,but also promote regional economic development. Process design and operating parameters provide an important reference value for the printing and dyeing wastewater treatment industry.

Effect of a biological activated carbon filter on particle counts

Due to the importance of biological safety in drinking water quality and the disadvantages which exist in traditional methods of detecting typical microorganisms such as Cryptosporidium and Giardia, it is necessary to develop an alternative. Particle counts is a qualitative measurement of the amount of dissolved solids in water. The removal rate of particle counts was previously used as an indicator of the effectiveness of a biological activated carbon (BAC) filter in removing Cryptosporidium and Giardia. The particle counts in a BAC filter effluent over one operational period and the effects of BAC filter construction and operational parameters were investigated with a 10 m3/h pilot plant. The results indicated that the maximum particle count in backwash remnant water was as high as 1296 count/ml and it needed about 1.5 h to reduce from the maximum to less than 50 count/ml. During the standard filtration period, particle counts stay constant at less than 50 count/ml for 5 d except when influ- enced by sand filter backwash remnant water. The removal rates of particle counts in the BAC filter are related to characteristics of the carbon. For example, a columned carbon and a sand bed removed 33.3% and 8.5% of particles, respectively, while the particle counts in effluent from a cracked BAC filter was higher than that of the influent. There is no significant difference among particle removal rates with different filtration rates. High post-ozone dosage (>2 mg/L) plays an important role in particle count removal; when the dosage was 3 mg/L, the removal rates by carbon layers and sand beds decreased by 17.5% and increased by 9.5%, respectively, compared with a 2 mg/L dosage.

Effect of biological activated carbon filter depth and backwashing process on transformation of biofilm community

The biological activated carbon (BAC) is a popular advanced water treatment to the provision of safe water supply. A bench-scale device was designed to gain a better insight into microbial diversity and community structure of BAC biofilm by using high-throughput sequencing method. Both samples of BAC biofilm (the first, third and fifth month) and water (inlet water and outlet water of carbon filter, outlet water of backwashing) were analyzed to evaluate the impact of carbon filter depth, running time and backwash process. The results showed that the microbial diversity of biofilm decreased generally with the increase of carbon filter depth and biofilm reached a steady-state at the top layer of BAC after three months' running. Proteobacteria (71.02%-95.61%) was found to be dominant bacteria both in biofilms and water samples. As one of opportunistic pathogen, the Pseudomonas aeruginosa in the outlet water of device (1.20%) was about eight times higher than that in the inlet water of device (0.16%) at the genus level after five-month operation. To maintain the safety of drinking water, the backwash used in this test could significantly remove Sphingobacteria (from 8.69% to 5.09%, p < 0.05) of carbon biofilm. After backwashing, the operational taxonomic units (OTUs) number and the Shannon index decreased significantly (p <0.05) at the bottom of carbon column and we found the Proteobacteria increased by about 10% in all biofilm samples from different filter depth. This study reveals the transformation of BAC biofilm with the impact of running time and backwashing.

EBAF^®曝气生物滤池在广西某污水处理厂的应用

该文阐述了EBAF^®曝气生物滤池的工艺原理和特点,介绍了其在广西某污水处理厂作为二级处理单元的应用,详细列举了设计参数、运行效能。为设计研究工作者提供借鉴。

强化生物滴滤技术深度治理大型城镇污水处理厂恶臭气体

为了解决城镇污水处理厂恶臭污染日益严峻,以及常规除臭技术难以深度去除产生的恶臭气体的问题,以市政污水处理厂调配水井收集的H_(2)S为研究对象,研究了一种添加微生物活性促进剂的一体化生物滴滤塔除臭技术,探究其工艺影响因素,并在大量研究数据的基础上,提出相关设计参数指导建议。结果表明:1)当进口臭气风量为3000 m^(3)/h,进口处H_(2)S的质量浓度为152~304 mg/m^(3)时,空床停留时间仅为8.6 s,强化生物滴滤塔的H_(2)S去除率可达99.9%,脱硫负荷(以H_(2)S计)可达62 g/(m^(3)·h)以上;2)强化生物滴滤塔添加生物促进剂可以缩短微生物驯化周期约60%,并在极低的pH条件(pH≤1.5)下长期稳定运行;3)以城镇污水处理厂臭气进口处H_(2)S的质量浓度为180 mg/m^(3)为例,设计空床停留时间(empty bed residence time,EBRT)为17 s,强化生物滴滤塔H_(2)S去除率可达99.9%,设备整体占地面积及体积均可减少30%~50%,为生物滴滤技术的实际应用提供参考价值。

Influence of pore structure on biologically activated carbon performance and biofilm microbial characteristics

Optimizing the characteristics of granular activated carbon(GAC)can improve the performance of biologically activated carbon(BAC)filters,and iodine value has always been the principal index for GAC selection.However,in this study,among three types of GAC treating the same humic acidcontaminated water,one had an iodine value 35%lower than the other two,but the dissolved organic carbon removal efficiency of its BAC was less than 5%away from the others.Iodine value was found to influence the removal of different organic fractions instead of the total removal efficiency.Based on the removal and biological characteristics,two possible mechanisms of organic matter removal during steady-state were suggested.For GAC with poor micropore volume and iodine value,high molecular weight substances(3500–9000 Da)were removed mainly through degradation by microorganisms,and the biodegraded organics(soluble microbial by-products,<3500 Da)were released because of the low adsorption capacity of activated carbon.For GAC with higher micropore volume and iodine value,organics with low molecular weight(<3500 Da)were more easily removed,first being adsorbed by micropores and then biodegraded by the biofilm.The biomass was determined by the pore volume with pore diameters greater than 100μm,but did not correspond to the removal efficiency.Nevertheless,the microbial community structure was coordinate with both the pore structure and the organic removal characteristics.The findings provide a theoretical basis for selecting GAC for the BAC process based on its pore structure.

某水厂微污染原水处理工程设计及运行分析

江苏某水厂原水中氨氮、高锰酸盐指数、铁等指标长期超标,达不到《地表水环境质量标准》(GB 3838—2002)Ⅲ类水标准,为微污染原水。针对原水水质特点,改造后的水厂净水工艺采用“预处理工艺+常规处理工艺+深度处理”的全流程净水工艺,其中预处理采用生物预处理工艺,常规处理采用“混凝沉淀+过滤”工艺,深度处理采用“臭氧-生物活性炭”工艺。改造后工艺运行稳定,对原水中的浑浊度、氨氮、高锰酸盐指数、铁、色度等均有较好的去除效果,出厂水水质指标稳定达到《生活饮用水卫生标准》(GB 5749—2006),其中出厂水浑浊度、氨氮、高锰酸盐指数、铁、色度分别稳定在0.5 NTU、0.5 mg/L、3.0 mg/L、0.05 mg/L、5度以下,平均去除率分别为99.6%、88.8%、73.3%、96.9%、82.9%。

臭氧-生物活性炭法深度处理钞票纸厂废水的试验研究

某钞票纸厂废水先进行生化处理,后进行深度处理,出水达到中水回用标准。本试验采用臭氧-生物活性炭法,提出“臭氧+活性炭生物滤池+纤维转盘滤池”的组合工艺,对钞票纸厂废水进行深度处理。试验结果表明,该工艺可以明显削减造纸废水的化学需氧量(COD)和悬浮物(SS)含量,COD从77.2 mg/L下降到28.8 mg/L,而SS从18.8 mg/L下降到4.5 mg/L,完全达到企业中水回用的标准。

特殊滤嘴研究进展

简要介绍了特殊滤嘴的作用、定义与分类 ,并按作用和添加剂 2种分类方法 ,较详细地综述了国内外活性炭滤嘴、生物滤嘴、铝硅酸盐类滤嘴、催化剂滤嘴、加香滤嘴以及其他滤嘴的研究进展和在卷烟加香与降焦减害中的作用。认为随着各国政府对卷烟的限制越来越严格 ,以及消费者对吸烟与健康的关注日益增强 ,仅凭一种单功能添加剂的特殊滤嘴已经难以满足卷烟市场的发展需求 ,特殊滤嘴已由一种添加剂单种功能向多种添加剂多功能的方向发展。提出在开发特殊滤嘴时 ,一定要加大科研投入 ,加强对各种滤嘴添加剂性能的基础性研究 ,了解和掌握各种滤嘴添加剂的降焦减害性能、用量、添加方法和生产成本等 ,这样 ,才能根据市场和卷烟设计的要求 ,有目的有选择性地将各种添加剂较佳地组合起来 ,开发出多功能具有理想降焦减害效果的特殊滤嘴 ,尤其是既具有加香作用 ,又具有降低多种有害烟气成分的特殊滤嘴。

挂膜方式对曝气生物滤池的影响

对新型接种挂膜与逐渐增加流量的自然挂膜两种方式进行了比较和分析。结果表明,挂膜后期前者的COD去除率可达90.36%,NH3-N去除率可达70.14%,后者则为87.69%和34.67%。前者生物膜生长情况好于后者,生物膜的成熟期缩短了4d;采用两级反应柱可以增加曝气生物滤池对NH3-N的去除效果。

曝气生物滤池生物量和生物活性的试验研究

采用上流式曝气生物滤池(BAF)处理城市纳污河水,应用脂磷法和TTC-脱氢酶活性法测定填料表面的生物量和生物活性,并得出其随填料高度的变化规律.同时研究了填料高度对溶解性有机物(SCOD)和氨氮去除率的影响.结果表明,曝气生物滤池生物量和生物活性的沿程分布不均匀,沿水流方向生物量和生物活性逐渐减小,进水端约40cm厚的填料集中了生物总量的60%以上,生物总活性的65%以上.有机物浓度对于生物量和生物活性的大小有很大影响,有机物浓度较低时会成为微生物生长的限制因子,导致生物量和生物活性都比较低.生物量和生物活性的大小对污染物的沿程去除率影响较大,74.6%的有机物在进水端40cm厚的填料层内得到降解,而氨氮(NH4+-N)的硝化集中在上层填料层内.

组合生物技术处理制药废水及其生物相

为有效治理化学制药废水和生物制药废水,采用水解酸化-活性污泥-曝气生物滤池组合工艺对制药废水进行室内模拟生物处理研究。结果表明:该工艺对出水COD、BOD5的去除率均大于90%,已达到《污水综合排放标准》(GB 8978-1996)二级标准。对生物相的显微镜观察分析表明,污泥絮体和生物膜生长良好,并出现变形虫、轮虫和漫游虫等原生和后生动物。对各构筑物中的细菌进行分离纯化,同时应用BIOLOG细菌鉴定系统进行鉴定,分别得到8株、3株、6株可培养的细菌。

BAF-BAC工艺在炼油厂二级出水深度处理中的应用

采用曝气生物滤池 生物活性炭工艺对炼油厂二级处理出水的深度处理进行中试研究 ,拟探索炼油厂废水深度处理用于循环冷却水补水新工艺 .结果表明 ,当进水COD浓度小于 1 30mg/L ,BAF滤速低于 4 2 4m/h条件下运行时 ,该工艺平均出水COD浓度小于 5 0mg/L ,平均出水浊度为 4 4 6NTU ,同时对NH+4 N也有一定的去除作用 .

生物活性炭滤池水生动物的控制研究

研究了生物活性炭(BAC)滤池中的水生动物种类组成、干池对其生长的影响和干池后各类水生生物的变化规律。结果表明:①BAC滤池炭滤后水体中轮虫种类和数量最多,优势种为单趾腔轮属(Monostyla),桡足类优势种为完美美丽猛水蚤(Nitocra pietschmanni),寡毛类为颗体虫(Aeolosoma);炭层附着水生生物中轮虫占59%～100%,线虫占0～41%。②干池4 d后炭滤后水和炭层附着水生动物密度明显低于干池前,炭滤后水中水生动物总数、轮虫、桡足类及炭层附着水生动物总数分别减少了83.8%、85%和67%、69%。③干池后不同水生动物的生长规律不尽相同。轮虫增长最为明显,其次为桡足类、寡毛类和线虫,炭层附着生物在44 d内增长均不明显。④干池能够提高BAC滤池对COD_(Mn)的去除率。因此干池是一种控制BAC滤池水生动物密度的有效措施。

海水曝气生物滤器污染物沿程转化规律的研究

以竹制空心生化球填料生物滤器处理海水养殖废水为对象，在水力负荷为0．58m3／[m3（填料）·h]、氨氮负荷为（0．35—0．46）g／[m3（填料）.h]、有机负荷约为11．58g／[m3（填料）.h]、气水比3：1、pH值为7．8～8．0、DO浓度2．8—5．8mg／L的条件下，考察了有机物和总氨氮（TAN）的沿程转化规律，分析了污染物的空间分布特性．结果表明：在给定的运行条件下，CODMn的主要去除区间在滤器的0～10cm高度，其中CODMn和溶解性CODMn在此处的去除率分别为49．12％和34．88％；TAN的主要去除区间为0～30cm，其中10cm处TAN的去除率为18％，30cm处为55％；生物量和生物活性由下向上呈递减的分布趋势；生物滤器污染物的主要去除区间为0-30cm，受到水质、水量冲击时，较高层的填料（30—60cm）起到了缓冲作用，将下层生物膜未能降解的污染物去除．

臭氧化-生物活性炭净化水厂的运行效能

吉林省前郭炼油厂生产区及其居民区的优质饮用水净化水厂采用臭氧化生物活性炭工艺处理传统水处理厂的滤后水。传统水处理厂由混凝、絮凝、沉淀和快速过滤组成。该饮用水深度净化厂运行性能稳定，最后出水完全达到国家饮用水水质标准。ＧＣ／ＭＳ分析结果表明，最后出水中含有５种微量有机污染物，不含重点及潜在的有害的微量有机污染物，而传统水处理厂的滤后水含有１１５种微量有机污染物。

进水负荷对硝化菌与异养菌竞争关系的影响

为优化反应器的脱氮设计,就水力负荷、温度对二级上向流曝气生物滤池内微生物种群结构的影响进行了研究。试验结果表明,在生物膜培养阶段,温度对氨氮氧化的影响要大于对COD降解的影响;较高的COD负荷会导致第一级反应器内的硝化点上移,第二级反应器的硝化速率因受第一级反应器出水残余有机物的影响而下降。在第二级反应器内氨氮的硝化速率明显加快,显示了单独驯化的硝化滤柱在氧化氨氮上的优势。在不同的进水COD负荷下,氨氧化菌与硝化菌的活性均有沿柱高逐渐增加的趋势,且当负荷较高时,不同高度处的氨氧化菌活性大多高于硝化菌的。异养菌的活性变化表明,生长较快的异养菌通常占据了反应器的进口区。

生物活性炭滤池反冲洗技术的优化

反冲洗是生物活性炭滤池运行中的一个关键步骤,合理优化反冲洗过程有助于改善其整体运行性能。为此,采用反冲洗废水的浊度、滤池运行中的水头损失变化、对有机物的去除效果以及出水细菌数等指标,比较分析了4种不同的反冲洗方式对生物活性炭滤池运行效果的影响,最终认为气水联合反冲洗更适合于生物活性炭滤池。

生物活性滤池饮用水除氨氮的影响因素

以实际沉淀池出水进行配水,通过模型实验,探讨了生物活性滤池(BAF)除氨氮的影响因素及作用机理。结果表明,滤前水中有机物含量和滤料粒径对BAF除氨氮能力影响较大。当采用沉淀池出水中自身携带的有机物时,BAF-1除氨氮效率为97%;当沉淀池出水中另配入2mg·L-1牛肉膏+2mg·L-1蛋白胨+2mg·L-1葡萄糖时,由于受到异养菌对溶解氧和生存空间竞争的限制,其除氨氮效率下降至51.0%。活性炭粒径采用0.8～1.2mm的BAF-1氨氮去除率比采用1.0～2.0mm的BAF-2高1.5%～16.7%。当滤前水氨氮浓度低于1.60mg·L-1时,BAF-1的氨氮去除率接近100%;当氨氮浓度逐渐升高时,由于受到溶解氧的限制,去除率逐渐下降。对滤前水进行预曝气充氧,能提高BAF-1的除氨氮效率。滤速对BAF-1除氨氮影响不显著。反冲洗可适当提高BAF-1的除氨氮效率。