串联微絮凝过滤工艺预处理低浊度海水研究

以三氯化铁和聚合氯化铝（PAC）作为絮凝剂，采用石英砂、沸石、锰砂和颗粒活性炭滤柱进行了单独及串联微絮凝过滤预处理低浊度海水的试验研究。结果表明，单独微絮凝过滤对浊度有较好的去除效果，其中锰砂的相对较差；颗粒活性炭滤柱对有机物的去除率较高，其余3种滤柱只能去除小部分的有机物；4种滤柱单独过滤的除盐能力均很弱。而串联过滤工艺明显提高了对有机物的去除率和除盐能力，几乎全部的浊度和绝大部分的有机物均能被有效去除。当采用三氯化铁作絮凝剂时，石英砂滤柱与颗粒活性炭滤柱串联的除盐效果最显著；而采用PAC作絮凝剂时，锰砂滤柱与颗粒活性炭滤柱串联的除盐能力最佳。     

Treatment of Algal-Laden Water: Pilot-Plant Experiences

In recent years an increase in the eutrophication of reservoirs has added to the problems of lowland surface-water treatment. A pilot plant was installed to test the effectiveness of various treatment regimes for a river source which was subject to occasional algal blooms, and a eutrophic reservoir source which was heavily contaminated with cyanobacteria ( Oscillatoria sp. ). The treatment processes adopted were dissolved-air flotation for chemical coagulation, sand and anthracite filtration, comparative disinfection stages using ozone and chlorine followed by granular activated carbon filtration.
The dissolved-air flotation plant was not particularly effective for the removal of algae, but the sand/anthracite filtration process was capable of removing 50% of the algae. The ozone disinfection stage was adequate for disinfection and also reduced algal numbers. Overall the chlorine/granular activated carbon method did not perform as effectively as the ozone/granular activated carbon process; the iatter process was +99% effective for algai control, with river and reservoir sources.     

三种深度处理工艺出水的微生物安全性比较

分别从浊度、颗粒数、细菌总数、HPC和浮游动物等方面进行研究,探讨了炭砂倒置工艺、炭砂滤池以及炭砂滤池/超滤复合工艺等三种给水深度处理技术对微生物安全性的保障作用。结果表明,炭砂滤池/超滤复合工艺对微生物的安全保障能力大大高于其他两种工艺。炭砂滤池/超滤复合工艺的出水水质非常稳定,浊度一般为0.01～0.03 NTU左右,平均为0.022 NTU,粒径2μm的颗粒数10个/mL;而其他两种工艺的出水浊度一般在0.1 NTU左右,颗粒数一般为几十至几百个/mL,且水质波动较大。炭砂过滤和炭砂倒置等两工艺出水的细菌总数和HPC均较高,存在一定的微生物风险;炭砂倒置工艺中的砂滤对降低微生物数量起到重要作用;复合工艺出水的细菌总数和HPC均很低。浮游动物能穿透炭砂滤层而出现在出水中;炭砂倒置工艺出水中的浮游动物数量有较大下降;复合工艺对浮游动物的截留效果非常好,出水中几乎不含浮游动物,只是偶尔检出数个轮虫。     

陶粒生物滤池与无烟煤滤池强化过滤效果对比

以北京某自来水厂处理密云水库蓄水的出水（混凝沉后水）为试验用水，通过中试对比研究了陶粒生物滤池与无烟煤滤池的过滤效果。结果表明，陶粒生物滤池与无烟煤滤池对水中颗粒物的去除效果接近；对于水中的浊度，无烟煤滤层对其去除效果较好，而陶粒滤层的过滤效果则较差，需要依靠石英砂的截污作用来降低浊度；陶粒对有机物的过滤效果优于无烟煤的，陶粒生物滤池对TOC的去除率为14．9％～30．2％，对CODMn的去除率为13．1％～38．5％；与无烟煤滤池相比，陶粒生物滤池具有水头损失增长快、周期较短、初滤水中颗粒物较多等缺点。     

DBPs removal in GAC filter-adsorber

A rapid sand filter and granular activated carbon filter-adsorber (GAC FA) were compared in terms of dissolved organic carbon (DOC) and disinfection by-products (DBPs) removal. A water treatment plant (WTP) that had a high ammonia concentration and DOC in raw water, which, in turn, led to a high concentration of DBPs because of a high dose of pre-chlorination, was investigated. To remove DBPs and DOC simultaneously, a conventional rapid sand filter had been retrofitted to a GAC FA at the Buyeo WTP in Korea. The overall removal efficiency of DBPs and DOC was higher in the GAC FA than in the sand filter, as expected. Breakthrough of trihalomethanes (THMs) was noticed after 3 months of GAC FA operation, and then removal of THMs was minimal (<10%). On the other hand, the removal efficiency of five haloacetic acids (HAA(5)) in the GAC FA was better than that of THMs, though adsorption of HAA(5) decreased rapidly after 3.5 months of GAC FA operation. And then, gradual improvement (>90%) in HAA(5) removal efficiency was again observed, which could be attributed to biodegradation. At the early stage of GAC FA operation, HAA(5) removal was largely due to physical adsorption, but later on biodegradation appeared to prevail. Biodegradation of HAA(5) was significantly influenced by water temperature. Similar turbidity removal was noticed in both filters, while better manganese removal was confirmed in the sand filter rather than in the GAC FA.     

BAC滤池对浊度和颗粒数的控制研究

传统的贾第鞭毛虫和隐孢子虫（简称“两虫”）检测方法存在诸多不足，为此选用浊度和颗粒数作为“两虫”的替代指标，以对浊度和颗粒物的去除率来衡量生物活性炭（BAC）滤池对“两虫”的控制效果。试验结果表明：采用颗粒数表征滤后水水质比采用浊度更适宜。过滤初期颗粒数从峰值降到50个／mL以下所需的时间比浊度降到0．1NTU所需的时间多1h左右。正常过滤期间BAC滤池进水浊度一般在0．1NTU以下，经过BAC滤池处理后，浊度得到进一步降低，平均去除率为52．7％。炭层对浊度的去除率为56．4％，其出水浊度基本上都低于0．05NTU，而砂层对浊度不但没有去除能力，反而使出水浊度平均上升了约3．7％。炭层对颗粒物的平均去除率为33．3％，砂层对颗粒物的平均去除率为8．5％。     

Optimization of the extended terminal subfluidization wash (ETSW) filter backwashing procedure

The increased passage of particles and microorganisms through granular media filters immediately following backwashing is a common problem known to the water treatment community as filter "ripening" or maturation. While several strategies have been developed over the years to reduce the impact of this vulnerable period of the filtration cycle on finished water quality, this research involves a recently developed filter backwashing strategy called the extended terminal subfluidization wash (ETSW). ETSW is a method of terminating the backwash cycle with a subfluidization wash for a period of time sufficient to pass one theoretical filter-volume of water upward through the filter. ETSW was shown to remove significantly greater quantities of backwash remnant particles thereby reducing the magnitude of filter ripening turbidity and particle count spikes. Optimum ETSW flow rates were determined for deep-bed anthracite and granular activated carbon filters herein by monitoring filter effluent turbidities and particle counts during the filter ripening period. Optimality of the coagulation process was also shown to influence the magnitude of filter ripening particle passage. ETSW was found to be equally effective for biological and conventional deep-bed anthracite filters.     

KDF55/椰壳活性炭/石英砂/沸石联用净化饮用水

考察了KDF55、石英砂、沸石、椰壳活性炭联用对饮用水的净化效果.结果表明,系统对浊度的去除主要发生在椰壳活性炭滤层;对铜、铬、铅等重金属离子的去除主要由KDF55滤层完成,去除率均可达80%以上;系统还可明显降低饮用水的硬度和CODMn.该系统在有效去除污染物的同时,又可向水中释放微量对人体有益的锌离子,对家用净水机的开发具有重要的参考价值.     

A sand/granular carbon filtration treatment system for removing aqueous pesticide residues from a marine toxicology laboratory effluent

Flow-through toxicity tests using marine organisms can generate large volumes of contaminated seawater effluent which should be treated to remove the contaminants before discharge into the environment. We have developed a sand filtration/carbon treatment system that removes from these effluents a diversity of organophosphate, organochlorine and pyrethroid pesticide residues down to their detection limit. The sand filter removed an average of 72% (range 4–99%) of the chemicals by continuously filtering suspended particulates and chemicals associated with the particulate. Following sand filtration, effluent water slowly percolates through granular carbon. Overall, organic removal efficiencies average 91% (range 24–99%). Initial construction cost was less than $20,000.     

A comparison of media types in acetate fed expanded-bed anaerobic reactors

A synthetic feed, containing acetate as the only carbon source, was used to start-up four different anaerobic expanded-bed reactors containing three different types of microbial attachment media. The media types used were low-density anthracite, granular activated carbon (GAC) and two sizes of sand. All media types were of the same average diameter, 0.7 mm, except for a smaller sand, 0.35 mm. These media types were chosen to compare surface roughness, macroscopic shear stresses due to upflow velocity and sphericity. The 0.7 mm sand required the greatest upflow velocity, 16 cm/s, while the other reactors had upflow velocities of 5.5–6.0 cm/s. Sand had the least surface roughness and GAC had the roughest surface, while anthracite had the most angular shape. At steady-state, the GAC reactor retained 3.75–10 times the attached biomass retained on the other media tested and the GAC reactor accumulated biomass at a faster rate during start-up. Shear losses reflected the biomass accumulation with the two sand and anthracite media having shear loss coefficients 6–20 times greater than that of the GAC medium. Sand induced the formation of sludge granules in both sand reactors with two species of methanogens and stability of the sludge blankets was critical to reactor performance. Scanning electron microscopy demonstrated that attached growth developed in crevices where biomass was protected from shear forces. Attached growth on the sand and anthracite media was located only in crevices, while the GAC medium is completely covered with crevices and biofilm developed on the entire GAC particle. Surface roughness was critical to biofilm development with the rougher surface providing the better attachment medium.     

强化活性炭滤池过滤性能的试验研究

采用在活性炭滤池前端投加不同药剂的方法深度净化某水厂沉淀池出水,考察了不同滤池形式、聚合氯化铝(PAC)投加量和阳离子型聚丙烯酰胺(PAM)投加量对沉后水浊度的去除效果。结果表明,在下向流滤池前端投加0.3 mg/L的PAC和0.03 mg/L的PAM可以明显强化活性炭滤池的过滤效果,使出水浊度小于0.1 NTU;与砂滤池出水相比,活性炭滤池对浊度的去除率提高了16.6%,CODMn去除率提高了56%;相应的滤池水头损失增加较快,但仍可以满足运行周期不小于24 h的设计要求;滤后水中铝和溴酸盐含量均满足《生活饮用水卫生标准》(GB 5749—2006)要求。     

O3/BAC对氯化消毒副产物的控制作用

采用臭氧化—生物活性炭(O3／BAC)深度处理工艺去除水中消毒副产物前质的试验结果表明，该工艺能够有效去除水中消毒副产物前质，可控制氯化消毒副产物的生成，其中主臭氧化对三卤甲烷前质和卤乙酸前质均具有很好的去除效果，生物活性炭对卤乙酸前质表现出较好的去除效果，但对三卤甲烷前质的去除效果有限；藻类、有机物等在滤层的累积使得砂滤池在同一工作周期中的不同阶段对水中三卤甲烷前质的去除效果有所不同，因而需要合理设置砂滤池的反冲洗周期。臭氧化—生物活性炭工艺充分发挥了臭氧化和生物活性炭两种技术的优点，并相互促进和补充，能够充分保障饮用水的安全性。     

不同滤料对丹江口水库水的过滤效果研究

以丹江口水库中试基地的沉淀池出水作为试验用水,对比研究了细石英砂单层滤料、粗石英砂单层滤料、无烟煤单层滤料及无烟煤-石英砂双层滤料的过滤效果。结果表明,4组滤柱对浊度的去除效果相近,但无烟煤-石英砂双层滤柱受进水浊度变化的影响较小,抗冲击能力较强,出水浊度相对稳定;无烟煤-石英砂双层滤柱与无烟煤滤柱对有机物的去除效果优于细石英砂与粗石英砂滤柱,无烟煤-石英砂双层滤柱与无烟煤滤柱对CODMn的去除率分别为(31.45±10.39)%和(28.23±9.15)%,对UV254的去除率分别为(13.05±5.3)%和(14.23±4.97)%;细石英砂滤柱水位增长最快,且运行周期最短,无烟煤-石英砂双层滤柱与无烟煤滤柱水位增长相对较慢,运行周期是细石英砂与粗石英砂滤柱的2～3倍。     

氧化铝涂层改性石英砂过滤性能研究

介绍了氧化铝涂层石英砂和未涂层石英砂对微污染牟水进行直接过滤的研究结果：无论对浊度，还是对有机物的综合去除，氧化铝涂层砂滤料过滤效果均明显优于未涂层砂滤料。     

Treatment of a colored groundwater by ozone-biofiltration: pilot studies and modeling interpretation

Pilot studies investigated the fates of color, dissolved organic carbon (DOC), and biodegradable organic matter (BOM) by the tandem of ozone plus biofiltration for treating a source water having significant color (50 cu) and DOC (3.2 mg/l). Transferred ozone doses were from 1.0 to 1.8 g O3/g C. Rapid biofilters used sand, anthracite, or granular activated carbon as media with empty-bed contact time (EBCT) up to 9 min. The pilot studies demonstrated that ozonation plus biofiltration removed most color and substantial DOC, and increasing the transferred ozone dose enhanced the removals. For the highest ozone dose, removals were as high as 90% for color and 38% for DOC. While most of the color removal took place during ozonation, most DOC removal occurred in the biofilters, particularly when the ozone dose was high. Compared to sand and anthracite biofilters, the GAC biofilter gave the best performance for color and DOC removal, but some of this enhanced performance was caused by adsorption, since the GAC was virgin at the beginning of the pilot studies. Backwashing events had no noticeable impact of the performance of the biofilters. The Transient-State, Multiple-Species Biofilm Model (TSMSBM) was used to interpret the experimental results. Model simulations show that soluble microbial products, which comprised a significant part of the effluent BOM, offset the removal of original BOM, a factor that kept the removal of DOC relatively constant over the range of EBCTs of 3.5-9 min. Although improved biofilm retention, represented by a small detachment rate, allowed more total biofilm accumulation and greater removal of original BOM, it also caused more release of soluble microbial products and the build up of inert biomass in the biofilm. Backwashing had little impact on biofilter performance, because it did not remove more than 25% of the biofilm under any condition simulated.     

固定化菌种处理锈蚀管网出水的研究

发生内腐蚀的管道出水往往使出厂饮用水水质部分超标,遂进行了相关的深度净化技术研究。从除铁除锰滤池中的成熟滤砂洗脱下滤膜,以铁锰细菌的选择性培养基进行分离纯化,共培养出5株铁锰降解菌。通过试验发现,铁锰降解菌在铁、锰共存的培养基中的生长情况要好于只含铁基质的,而在只含有锰的基质中不生长。将降解有机物的工程菌和铁锰降解菌固定在同一个反应器的不同滤料上并处理管网出水(浊度为1.5NTU、色度≥25倍、有腥味),结果表明,一体式固定菌种反应器对铁、锰和高锰酸盐指数的去除率可达98%、96%和55%,处理出水的浊度<0.5NTU,色度<15倍,没有嗅味。     

粉末活性炭—混凝—超滤联用处理含藻水的研究

考察了直接超滤、混凝-超滤、粉末活性炭（PAC）-超滤和PAC-混凝-超滤四种工艺对含藻水的处理效果及超滤膜的运行性能。试验结果表明,四种工艺对浊度、藻类均有较好的去除效果,出水中均未检出藻类,且浊度均低于0．2NTU;PAC-混凝-超滤联合处理工艺对有机物的去除效果最好,对UV254和TOC的去除率分别可达到32．99％和46．72％,且该工艺能有效缓解超滤膜直接过滤所产生的膜通量迅速下降及反冲洗后难以恢复的问题。     

强化常规工艺对三卤甲烷前体物的去除效果研究

分别通过小试和生产性试验研究了强化混凝和强化过滤对三卤甲烷前体物的去除效果。结果表明,强化混凝能有效提高三卤甲烷前体物的去除效果,两组试验去除率最高分别可提高至50.62%和44.75%;相对石英砂滤池,采用炭砂滤池和活性无烟煤滤池进行强化过滤可将三卤甲烷前体物的去除率提高10%~20%,强化过滤出水加氯消毒后三卤甲烷生成总量比石英砂滤池出水低30%~40%,强化过滤后三卤甲烷生成风险显著降低。     

Biofiltration of wastewater treatment plant effluent: effective removal of pharmaceuticals and personal care products and reduction of toxicity

This study investigates biofiltration for the removal of dissolved organic carbon (DOC), pharmaceuticals and personal care products (PPCPs), and for the reduction of non-specific toxicity expressed as baseline toxicity equivalent concentration (baseline-TEQ). Two filtering media, sand and granular activated carbon, were tested. The influence of pre-ozonation and empty-bed contact time (EBCT, from 30 to 120 min) was determined. The experiments were performed at a pilot-scale with real WWTP effluent. A previous study showed that biological activity had developed on the filtering media and dissolved organic removal had reached a steady state before sampling commenced. The results show that biological activated carbon (BAC) has a good potential for the removal of DOC (35-60%), PPCPs (>90%) and baseline-TEQ (28-68%) even without pre-ozonation. On the contrary, the sand shows limited improvement of effluent quality. Varying the EBCT does not influence the performance of the BAC filters; however, dissolved oxygen concentration could be a limiting factor. The performances of the BAC filters were stable for over two years suggesting that the main mechanism of organic matter and PPCPs removal is biodegradation. It is concluded that BAC filtration without pre-ozonation could be implemented as a low cost advanced treatment option to improve WWTP effluent chemical quality.     

Fate of N-nitrosodimethylamine, trihalomethane and haloacetic acid precursors in tertiary treatment including biofiltration

The presence of disinfection by-products (DBPs) such as trihalomethanes (THMs), haloacetic acids (HAAs) and N-nitrosamines in water is of great concern due to their adverse effects on human health. In this work, the removal of N-nitrosodimethylamine (NDMA), total THM and five HAA precursors from secondary effluent by biological activated carbon (BAC) is investigated at full and pilot scale. In the pilot plant two filter media, sand and granular activated carbon, are tested. In addition, we evaluate the influence of ozonation prior to BAC filtration on its performance. Among the bulk of NDMA precursors, the fate of four pharmaceuticals containing a dimethylamino moiety in the chemical structure are individually investigated. Both NDMA formation potential and each of the studied pharmaceuticals are dramatically reduced by the BAC even in the absence of main ozonation prior to the filtration. The low removal of NDMA precursors at the sand filtration in comparison to the removal of NDMA precursors at the BAC suggests that adsorption may play an important role on the removal of NDMA precursors by BAC. Contrary, the precursors for THM and HAA formation are reduced in both sand filtration and BAC indicating that the precursors for the formation of these DBPs are to some extent biodegradable.