改性砂高速过滤技术用于污水再生回用的研究

采用SJ材料作为改性剂对石英砂滤料进行改性,经测定,其表面的物理化学性能优于石英砂.将改性砂应用于煤砂双层滤料高速过滤工艺,并处理某污水厂的二级出水,其出水的平均浊度、COD、UV254、PO43--P分别为1.23 NTU、27.4 mg/L、0.133 5 cm-1、0.42 mg/L,对各项指标的去除率均高于石英砂滤料,且完全符合GB/T 18920-2002标准中的城市杂用水水质要求.研究发现,高速过滤工艺应该以自然条件下的最大滤速为起始滤速;污染物积累和滤层负压导致水中溶解气体的析出会减小有效过水断面面积,这是引起滤速衰减的主要原因.     

BAF/O_3预处理工艺后砂滤池的除污效果

以珠江广州段源水为处理对象,考察了曝气生物滤池（BAF）／臭氧（O3）预处理工艺后砂滤池的除污效果。结果表明,砂滤池出水CODMn、NH4^＋ -N和浊度的平均值分别为2．19、0．099mg／L和0．225NTU,NO2^- -N的最高值为0．003mg／L;相对于沉淀池出水,砂滤池对上述指标的平均去除率分别为27．60％、66．88％、69．88％和98．53％。BAF和臭氧塔提高了源水的DO浓度,其对浊度和有机物的去除作用降低了砂滤池的反冲洗频率,从而有利于提高生物膜中微生物的数量和活性;臭氧氧化可提高源水的可生化性,且水中没有残留臭氧,也为砂滤池的生物降解作用提供了有利条件。     

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。     

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％。     

Comparison of Algal Penetration Through Rapid-Gravity Filter Beds

T ests OF FOUR types of filter media are presented, which show that granular activated carbon performs marginally less well than anthracite/sand or anthracite/sand/garnet in the removal of algae, particulate organic carbon, iron and turbidity. The lengths of run which are achieved by the two granular activated carbon filters are also shorter than those of the other two media. A three-layer filter is better than the anthracite/sand filter for particulate organic carbon, iron and turbidity removal, and the filtrate contains lower mean concentrations of algae.     

深圳市沙头角水厂深度处理工艺研究与设计

根据原水低浊、高藻、碱度及硬度偏低的特点,充分利用水厂现有构筑物进行升级改造,通过试验确定采用絮凝沉淀＋活性炭滤池＋超滤的净水工艺,并预留再矿化工艺。分析了中试系统的处理效果,并对升级改造的活性炭滤池、超滤膜等主要构筑物设计进行了阐述。     

饮用水钙硬度去除中C/Ca值对CaCO3结晶的影响

饮用水中钙硬度去除效能主要受CaCO3结晶过程影响。通过改变C/Ca值模拟饮用水钙硬度去除,考察不同C/Ca值条件下,溶液体系pH值和Ca^2+浓度变化、上清液浊度变化以及结晶产物颗粒粒径分布、晶型和形态,以阐明钙硬度去除过程中CaCO3结晶行为。结果表明:试验条件下结晶产物均为方解石;溶液体系中加入的CO3^2-首先发生质子化,提高体系pH值,然后与Ca^2+结晶反应降低体系pH值;C/Ca值的增大提高了pH值,有助于Ca^2+的去除,但同时也会提高结晶产物颗粒数量、密度和减小结晶产物颗粒粒径,导致上清液浊度增大。饮用水钙硬度去除中要综合考虑残余Ca^2+浓度、出水pH值和浊度以及混凝剂用量等来优化确定C/Ca值。     

Transport and fate of Cryptosporidium parvum oocysts in intermittent sand filters.

The transport potential of Cryptosporidium parvum (C. parvum) through intermittent, unsaturated, sand filters used for water and wastewater treatment was investigated using a duplicated, 2³ factorial design experiment performed in bench-scale, sand columns. Sixteen columns (dia=15 cm, L=60 cm) were dosed eight times daily for up to 61 days with 65,000 C. parvum oocysts per liter at 15°C. The effects of water quality, media grain size, and hydraulic loading rates were examined. Effluent samples were tested for pH, turbidity, and oocyst content. C. parvum effluent concentrations were determined by staining oocysts on polycarbonate filters and enumerating using epifluorescent microscopy. At completion, the columns were dismantled and sand samples were taken at discrete depths within the columns. These samples were washed in a surfactant solution and the oocysts were enumerated using immunomagnetic separation techniques.

The fine-grained sand columns (d₅₀=0.31 mm) effectively removed oocysts under the variety of conditions examined with low concentrations of oocysts infrequently detected in the effluent. Coarse-grained media columns (d₅₀=1.40 mm) yielded larger numbers of oocysts which were commonly observed in the effluent regardless of operating conditions. Factorial design analysis indicated that grain size was the variable which most affected the oocyst effluent concentrations in these intermittent filters. Loading rate had a significant effect when coarse-grained media was used and lesser effect with fine-grained media while the effect of feed composition was inconclusive. No correlations between turbidity, pH, and effluent oocyst concentrations were found. Pore-size calculations indicated that adequate space for oocyst transport existed in the filters. It was therefore concluded that processes other than physical straining mechanisms are mainly responsible for the removal of C. parvum oocysts from aqueous fluids in intermittent sand filters used under the conditions studied in this research.     

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。     

聚氯乙烯离心母液的处理及回用

采用接触氧化法处理悬浮法生产聚氯乙烯产生的离心母液,工程实践表明:离心母液经接触氧化工艺处理后COD去除率>85%,出水COD<50mg/L;再经过砂滤、臭氧氧化、活性炭过滤等深度处理后,出水COD、pH、浊度、电导率均达到回用要求。深度处理费用低于自来水基本水费(天津),也低于用自来水制备脱盐水的费用。     

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。     

改性石英砂过滤技术用于污水再生回用的研究

通过对石英砂滤料进行改性,研究了改性后滤料表面性能的变化,考察了不同改性滤料对城市污水厂二级处理出水中污染物的去除效果.表面性能分析的结果表明,经不同改性剂涂层后其表面性能存在差异,其中铁铝砂、铁砂及SJ型砂的物理稳定性较好,且表面含有金属氧化物,因而提高了滤料的截污性能.二级处理出水的过滤试验表明,石英砂、铁铝砂、铁砂和SJ型砂对浊度的去除率均在60%以上;与石英砂相比,改性砂对COD、UV254和PO3-4-P的去除率均有所提高,且过滤出水中的PO3-4-P<1mg/L,其中铁砂和SJ型砂的过滤效果稳定,对COD、UV254和PO3-4-P的平均去除率提高明显,分别提高了26%、79%和40%以上.改性滤料经再生后可以重复使用,在城市污水再生回用中具有良好的应用前景.     

Analysis of the long-term performance of an on-site greywater treatment plant using novel statistical approaches

This paper analyses the performance of three greywater treatment systems: RBC, MBR and stand-alone sand filter. Pollutants' concentrations in raw greywater exhibited a long-term increase. The RBC and MBR exhibited high removal efficiency, while the sand filter performance was much poorer. In order to apply control measures, dynamic regression SPC (DRSPC), SPC (statistical process control) with variable control limits, was developed. DRSPC often better described underlying long-term trends. For RBC effluent, DRSPC had the highest advantage for TKN. For MBR effluent, it had the highest advantage for turbidity and COD_t. For the stand-alone sand filter effluent, the DRSPC advantage was much lower. Constant density curves showed low negative correlation between inflow and outflow VSS, and no correlation between inflow and outflow BOD_t for the RBC. For the MBR, no slope was identified for VSS and low negative slope for BOD_t. The BOD_t of the sand filter effluent revealed positive correlation with inflow.     

New media for effluent filtration

Although deep bed filtration is not new in industrial effluent treatment and advanced sewage treatment, new filter media have been investigated with a view to improving the process. The usual media, like sand and anthracite, may be augmented or replaced by hydroanthracite, pumice and expanded slate. The properties of these media are described. Laboratory and pilot tests illustrate their use for effluent treatment in Switzerland.     

Transport and fate of Cryptosporidium parvum oocysts in intermittent sand filters

The transport potential of Cryptosporidium parvum (C. parvum) through intermittent, unsaturated, sand filters used for water and wastewater treatment was investigated using a duplicated, 2³ factorial design experiment performed in bench-scale, sand columns. Sixteen columns (dia=15 cm, L=60 cm) were dosed eight times daily for up to 61 days with 65,000 C. parvum oocysts per liter at 15°C. The effects of water quality, media grain size, and hydraulic loading rates were examined. Effluent samples were tested for pH, turbidity, and oocyst content. C. parvum effluent concentrations were determined by staining oocysts on polycarbonate filters and enumerating using epifluorescent microscopy. At completion, the columns were dismantled and sand samples were taken at discrete depths within the columns. These samples were washed in a surfactant solution and the oocysts were enumerated using immunomagnetic separation techniques.The fine-grained sand columns (d₅₀=0.31 mm) effectively removed oocysts under the variety of conditions examined with low concentrations of oocysts infrequently detected in the effluent. Coarse-grained media columns (d₅₀=1.40 mm) yielded larger numbers of oocysts which were commonly observed in the effluent regardless of operating conditions. Factorial design analysis indicated that grain size was the variable which most affected the oocyst effluent concentrations in these intermittent filters. Loading rate had a significant effect when coarse-grained media was used and lesser effect with fine-grained media while the effect of feed composition was inconclusive. No correlations between turbidity, pH, and effluent oocyst concentrations were found. Pore-size calculations indicated that adequate space for oocyst transport existed in the filters. It was therefore concluded that processes other than physical straining mechanisms are mainly responsible for the removal of C. parvum oocysts from aqueous fluids in intermittent sand filters used under the conditions studied in this research.     

Simulated Cryptosporidium removal under swimming pool filtration conditions

There has been no information available on the removal of Cryptosporidium oocysts or oocyst‐sized particles under the sand filtration conditions normally used for swimming pool water treatment. A pilot sand filtration plant has therefore been constructed at The University of Wales Swansea and operated under swimming pool conditions (25 m/h downflow, 30°C, 1.5 mg/L free chlorine, pH 7.3 to 7.5, alkalinity 120–150 mg/L as calcium carbonate). Removal of fluorescent polystyrene particles of a size range (1–7 μm) similar to the size of Cryptosporidium oocysts (about 5 μm) without added coagulant was less than 50%. Removal of the particles under the operating conditions above but with the addition of either of the coagulants polyaluminium chloride (PAC) or aluminium sulphate was capable of giving better than 99% removal of the particles.     

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.     

改性滤料强化接触氧化法处理高锰矿井水的研究

以鹤壁煤业集团九矿矿井水的混凝沉淀处理出水为原水,重点研究了改性滤料强化接触氧化除锰工艺的影响因素和运行参数,并对除锰机理进行了探讨.结果表明:采用1g的高锰酸钾溶液改性的锰砂除锰效果优良,当控制滤层厚度>800 mm、滤速为7-9 m/h、过滤周期为22 h时,出水锰含量<0.2 mg/L;为防止破坏活性滤膜,反冲洗的膨胀率应控制在30%左右.该方法除锰高效,且具有启动快、成熟期短、易改性的特点.     

高铁矿井水回用处理工艺研究

针对韩桥矿高铁矿井水质,考察了混凝＋沉淀＋过滤回用处理工艺除铁的最佳运行条件。结果表明,以聚合氯化铝（PAC）作为混凝剂,最佳投药量为80mg／L时,铁的去除率可达到91％;选择天然锰砂作为滤料,滤速在8～10m／h,进水pH值高于6．05,滤层高度大于75cm时,锰砂除铁效果较好,出水铁含量在0．1mg／L以下,可以满足《城市污水再生利用工业回用水水质》（GB／T19923--2005）中的限值要求。     

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.