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.

Purification of Stormwater Using Sand Filter

Rain water is an important source to feed the groundwater aquifer, whether directly or by harvesting and recharging. The importance of purification is for reducing the risk of pollutants from recharging runoff rainwater. The use of sand filter as a technique considered not expensive and commonly used for removing contaminants from water and wastewater treatment industries. The methodology used laboratory testing, by designing and constructing pilot plant to experiment the sand filter for purification, and made simulation for the infiltration of storm water through sand filter of 2 meters depth, in order to find the relationship between the depth on one hand, and the removal of suspended solids and fecal coliforms bacteria on the other hand, to know the effective depth that gets the purification. The research results during three days of infiltration show that the sand filter can remove fecal coliforms bacteria at a depth of 150 cm, and provide purified water with a concentration of suspended solids less than 20 mg/liter at a depth of 75 cm.

Study of the Purification Performance of Sand Filter Drained in a Complementary Treatment of Urban Wastewater under Soil and Climatic Conditions of the Southern Tunisia

In?ltration percolation is a rustic and extensive purifying technique which is capable of completely oxidizing and decontaminating wastewater. The object of the present study is to validate on a real scale the findings gotten in pilot laboratory. It is notably to confirming the purification performances and decontamination of secondary effluent by sand filter drained under an intense wild plant. For this, a basin of 100 m2 of infiltration surface equipped with two wells of sampling in the center and in the periphery, has been constructed in irrigated perimeter of Dissa in Gabes (south east of Tunisia). Our results show that essential of the COD is eliminated in first 50 centimeters in sand filter and the presence of wild plant on the surface of infiltration damaged quality of filtered water. The follow-up of the organic nitrogen and ammonium show the good performances of process in elimination of nitrogenous pollution. The rate of exhaustion is about 100% and this since first 50 centimeters of filtration. The sand filter retains the different shapes of the phosphor by adsorption and precipitation in the superficial horizon. The elimination of the bacterial pollution is high, it varying from 0.1 to 2.5 Ulog. The bacterial purification remained low after 50 cm filtration. Indeed, with 50 cm depth, the quality of the filtrate is slightly better than the influent with still tendency to higher removal in the center than in periphery of the basin.

Effect of the Design Parameters on the Performance of Inner-Recycling Continuous Sand Filter

A novel integrated water treatment facility, inner-recycling continuous sand filter, is discussed. The theory of micro-flocculation is applied in the sand-washing circulation system with continuous filtration and backwashing. The design and operation parameters, which affect the performance of the filter, are discussed. The key design parameters are provided as follows: diameter of filter material is 0.7 to 1.0 mm, depth of filter bed is 0.6 m, filtration velocity is less than 12 m/h, ratio of gas to water is 9:11 and sand recycling rate is 2 to 4 mm/min.

Impacts of backwashing on micropollutant removal and associated microbial assembly processes in sand filters

Backwashing is crucial for preventing clogging of sand filters.However,few studies have investigated the effect of backwashing on micropollutant removal and the dynamic changes in the microbial community in sand filters.Here,we used a series of manganese and quartz sand filters under empty bed contact times(EBCTs)of 2 h and 4 h to explore variations in micropollutant degradation and temporal dynamics of the microbial community after backwashing.The results showed that the removal efficiencies of caffeine,sulfamethoxazole,sulfadiazine,trimethoprim,atrazine,and active biomass recovered within 2 d after backwashing in both types of sand filters at 2-h EBCT,but the recovery of sulfadiazine and trimethoprim was not observed at 4-h EBCT.Moreover,the removal efficiency of atenolol increased after backwashing in the manganese sand filters,whereas maintained almost complete removal efficiency in the quartz sand filters at both EBCTs.Pearson correlation analysis indicated that microbial community composition gradually recovered to the pre-backwashing level(R increased from 0.53 to 0.97)at 2-h EBCT,but shifted at 4-h EBCT(R<0.25)after backwashing.Furthermore,the compositions of the recovered,depleted,and improved groups of microbes were distinguished by applying hierarchical clustering to the differentially abundant amplicon sequence variants.The cumulative relative abundance of recovered microbes at 2-h EBCT was 82.76%±0.43%and 46.82%±4.34%in the manganese and quartz sand filters,respectively.In contrast,at 4-h EBCT,the recovered microbes dropped to 15.55%–25.69%in both types of sand filters.

Comparing unamended and Fe-coated biochar on removal efficiency of bacteria,microspheres,and dissolved phosphorus in sand filters

The effects of uncoated and Fe-coated biochars(BC)on the removal of bacteria,microspheres,and dissolved reactive phosphorus(DRP)in sand filters were compared.Filters were packed with 1.2 or 2.0-mm sand mixed with 30%(vol/vol)uncoated BC,Fe-coated BC,or a control without BC.Removal of E.coli,Salmonella,and Enterococci increased from 23,42,and 25%in the unamended 1.2-mm sand to 48,80,and 75%in the uncoated BC treatment,though only the increase for Enterococci was significant(p<0.05).For the Fe-coated BC,removal efficiencies were 89,93,and 94%,respectively,which were all significantly(p<0.05)greater than the unamended sand but only the removal of E.coli was significantly greater than the uncoated BC sand filter.For the 2.0-mm sands,the only significant increase in removal following BC addition was observed for Salmonella.Trends in microsphere removal were generally consistent with bacteria.Removal of DRP in the unamended and uncoated BC filters was 33 and 13%(p>0.05),respectively,whereas removal in the Fe-coated BC filters was 98%(p<0.05).Results from batch sorption experiments indicate that both BCs similarly increased bacterial sorption to sand.In contrast,DRP sorption to the unamended and uncoated BC-amended sands were similar(p>0.05)with DRP sorption to the Fe-coated BC-amended sand being significantly greater(p<0.05).Results indicate that Fe-coated BC is more effective at retaining DRP than bacteria and microspheres in sand filters.

Role of sand size on bacterial retention in biochar-amended sand filters

The addition of biochar to sand columns can enhance the retention of bacteria and thus may provide a management strategy for removing bacteria from tile-drainage waters.In this study,the role of sand size as a factor in controlling microbial reten-tion in biochar-amended sand columns was investigated.Laboratory column experiments were conducted to quantify the removal of two bacterial isolates(E.coli and Salmonella)and polystyrene microspheres in 10-cm-long columns packed with clean sand of three different sizes(0.25,0.71,and 1.19 mm)at four biochar concentrations(0%,5%,10%,and 15%).Sorption studies were also performed to help identify the relative roles of sorption and physical straining on the removal of bacteria and microspheres within the columns.For the large sand,the log10 removal values(LRV)for E.coli increased from 0.22 to 0.49 for the 0%and 15%biochar concentrations,respectively,while LRV for Salmonella increased from 0.19 to 0.68.For the small sand,increasing biochar concentration from 0%to 15%increased LRV from 0.11 to 1.9 for E.coli and from 0.20 to 4.6 for Salmonella.In comparison,LRV for microspheres in the 15%biochar columns was only minimally higher than the unamended columns for all three sand sizes.Results from the sorption studies show that high sorption coefficients generally correlated with high LRV indicating that sorption rather than physical straining was the primary mechanism of retention in the columns.Results from this study further our understanding of bacterial retention in biochar-amended porous media.

新型活性砂滤罐深度脱氮性能与微生物群落结构研究分析

为进一步减少氮污染物排放,满足城市污水处理厂深度脱氮提标改造的需求,本研究使用新型活性砂滤罐以二沉池出水为对象进行深度脱氮试验,考察不同调控因子对总氮(TN)去除效果以及微生物群落结构的影响。结果表明,最优水力停留时间(HRT)为0.28 h,最佳碳氮比(C/N)为6:1,在此条件下出水TN浓度低于1.5 mg/L,优于现有深度脱氮工艺;为节约运行成本,HRT可调整至0.13~0.23 h,C/N参数不变,TN出水浓度低于4 mg/L。使用乙酸钠时微生物的响应时间比使用甲醇时更短,但高C/N条件下使用甲醇时脱氮效果比使用乙酸钠更好。16s rRNA高通量测序结果表明,系统主要脱氮功能微生物为Saccharibacteria_genera_incertae_sedis、Anaerolineaceae、Longilinea、Rhodocyclaceae、Chlorobium、Thiobacillus、Betaproteobacteria等,Anaerolineaceae主要聚集于装置底部。反冲洗会导致中下部生物膜量较高,但滤床循环运行的方式能将装置底部的反硝化菌转移至滤料顶部,使微生物在装置内的分布更加均匀,从而保证较好的深度脱氮效果。

不同改性方法对生物砂滤池生物膜特性及处理受污染原水效果的影响

通过对普通石英砂(QS)进行氨基及铝钙双氢氧化物改性制得氨基改性砂(AMS)和铝钙双氢氧化物改性砂(CAS),分别以QS、AMS、CAS为滤料填充滤池进行挂膜,研究了不同石英砂表面的生物膜量、生物活性、胞外聚合物(EPS)的特性及对受污染原水的处理效果。结果表明,挂膜成功后CAS表面的生物活性最高,为42.00 mgO_(2)/(g·h),生物膜量和胞外聚合物的含量最大,分别为12.43 mg/g、105.09 mg/(g·SS),对COD_(Cr)、NH^(+)_(4)-N的去除率分别稳定在58.20%、89.50%;AMS表面的生物活性、生物膜量、EPS平均含量分别为32.97 mgO_(2)/(g·h)、9.07 mg/g、93.41 mg/(g·SS),对COD_(Cr)、NH^(+)_(4)-N的去除率分别为54.60%、85.10%。三种石英砂表面生物量分布均沿水流方向递减,EPS的含量从溶解性胞外聚合物(SL-EPS)到紧密附着性胞外聚合物(TB-EPS)呈上升趋势。

复合改性砂滤料制备及生物砂滤池对受污染原水的净化效果

为改善普通石英砂(QS)表面特性,提高生物砂滤池生物附着量及对水中污染物的去除效果,对QS进行氨基、铝离子及铝钙双氢氧化物改性,制得氨基改性砂(AMS)、铝离子改性砂(ALS)和铝钙双氢氧化物改性砂(CAS),以四种滤料填充滤池考察对受污染原水的净化效果。结果表明,与QS相比,ALS与CAS表面覆盖了金属离子,AMS、ALS、CAS表面形态及比表面积均得到改善,成膜后表面生物附着量分别增加3.6、5.5、6.9 mg/g;滤速为5 m/h时,CAS滤池对浊度和COD平均去除率分别为90.1%、51.8%。与AMS、ALS滤池相比,CAS滤池表面生物量最大,对水中污染物去除效果良好。

应对供水突发公共事件的炭砂滤池应急改造技术研究

依托武汉某水厂开展中试考察不同炭砂配比对水中污染物的去除效果,探究不同冲洗参数对冲洗效果的影响。结果表明,最佳炭层和砂层厚度为800 mm和500 mm,最佳冲洗方式为16 L/(m^(2)·s)气冲3 min、间隔2 min、13 L/(m^(2)·s)水冲9 min。1#炭砂滤柱对氨和高锰酸盐指数的平均去除率分别为46.99%和54.81%,其对有机物的去除效果明显优于砂滤柱,当进水浊度低于2 NTU时,1#炭砂滤柱浊度平均去除率可达85.67%,出水满足厂区滤后水浊度指标的要求。采用最佳炭砂配比和冲洗方式,1#炭砂滤柱滤后水浊度和高锰酸盐指数去除率可达89.56%和66.27%。结合上述中试结果,并通过对实际工程中砂滤池及炭砂滤池进行调研,形成一套完整的炭砂滤池工程改造方案,为应对供水突发事件时砂滤池改造为炭砂滤池提供一定的理论指导。

炭砂滤池去除水中典型污染物和嗅味物质中试试验

依托武汉某水厂开展中试探究炭砂滤池对水中常规污染物和嗅味物质的去除效果。中试滤柱总设计流量为15 m^(3)/h,正常滤速为8 m/h,滤料上层采用Φ1.5 mm颗粒活性炭,滤料下层采用0.95 mm石英砂。试验期间,最优炭砂组合比例的滤柱对浑浊度、高锰酸盐指数和氨的平均去除率可达77.22%、55.55%和39.12%,出水水质优于《生活饮用水卫生标准》(GB 5749—2022);对臭和味的去除效果优于水厂砂滤池,出水清澈透明无异味;对藻类的平均去除率可达70.25%,与水厂砂滤池相当;对土臭素和2-甲基异莰醇的平均去除率可达95.83%和68.86%,出水浓度均低于其限值,去除效果明显优于水厂砂滤池。

基于GNSS+IMU的草方格固沙机自动巡航控制系统

为了实现草方格固沙机的智能化工作,提出了一种基于GNSS+IMU的草方格固沙机自动巡航控制系统。系统以STM32F407VGT6作为主控芯片,将GNSS(全球导航卫星系统)和IMU(惯性测量单元)的位置、速度和航向角数据通过卡尔曼滤波算法融合,得到最优估计数据;然后,将最优估计数据输入增量式PID算法,以实现草方格固沙机在预定义区域内稳定的导航工作。同时,设计了Android APP终端,实现了用户终端对草方格固沙机的智能监控。研究结果表明:系统导航工作直线航向角偏差RMS不超过0.45,最大偏差不超过1.5°,满足草方格固沙机自动巡航工作的基本需求,体现了草方格固沙机在智能化定位导航方面的可行性与稳定性,可为草方格固沙机实现荒漠化治理提供依据。

高合金钢冶炼用锆质引流砂的研制与应用

以锆英砂、铬铁矿和石英砂为主要原料,制备了满足电炉钢包高合金钢冶炼需求的锆质引流砂,研究了石英砂含量对其组成、结构和性能的影响。结果表明:经高温热处理后,随着石英砂含量增加,试样的线变化率逐渐增大,显气孔率明显减小,体积密度先减小后增大,各试样内各颗粒均为点接触为主,形成了以K_(2)O-Al_(2)O_(3)-SiO_(2)-FeO为主的低熔相,高温耐压强度略有增大,烧结层厚度增加,促进了引流砂烧结。针对宝钢电炉钢包高合金钢种冶炼(合金量Cr+Ni+Mo≥8%),采用锆质引流砂替代铬质引流砂进行应用,目前已稳定使用9个月(合计210炉次),钢包自动自开率明显改善,由85.0%提高至97.2%。

煤砂双层滤料滤池气水反冲洗参数探究及应用

为解决济阳某10万m^(3)/d水厂煤砂双层滤料滤池反冲洗不彻底、滤料流失、混层等问题,对滤池进行了水反冲流体力学(CFD)模拟,指导水冲阶段反冲洗强度的选取,并在现场进行了中试试验。试验结果表明:采用气水反冲洗模式,当气冲阶段qs=17.0 L/(m^(2)·s)、t=3 min时;水冲阶段,梯度提升水冲强度,在q_(w1)=4.5 L/(m^(2)·s)、t_(1)=2 min,q_(w2)=7.0 L/(m^(2)·s)、t_(2)=3 min,q_(w3)=17.5 L/(m^(2)·s)、t_(3)=3 min时,反冲洗后滤料含泥量可控制在0.1%以下,并可恢复滤料混层。将最优参数在工程现场应用后,有效解决水厂反冲洗问题,延长过滤周期,滤池反冲洗年耗水量减少192720 m^(3)。

降低FPSO淡水系统出水含盐度的应用研究

阐述海水造淡水机的运行特点和工艺特色,对比降低造淡水机出口淡水含盐度的成分差异,通过清洗矿砂滤器、维修清洗渗透膜、测试造淡水机的压力应用效果,为今后降低造淡水机含盐度提供参考。

炼化污水总排水质提标升级改造技术总结

结合炼化企业污水处理场实际运行工况及存在问题,论述了污水总排水质提标升级主要改造内容,重点介绍了高效低氧一体化生物处理、臭氧催化氧化、多级曝气生物滤池、微砂加碳高效沉淀池深度污水处理技术特点。工业应用结果表明,该组合技术先进可靠,去除污水COD、氨氮、总磷效率高,总排污水平均COD 10.92 mg/L,BOD 2.9 mg/L,氨氮0.14 mg/L,总氮6.62 mg/L,总磷0.13 mg/L,石油类0.83 mg/L,完全达到《陕西省黄河流域污水综合排放标准》(DB 61/224—2018)要求,环保效益明显,每年减排COD 3309.4 kg,氨氮4142.4 kg,悬浮物57.6 kg,对改善周边生态环境发挥了积极作用,在国内炼化企业废水综合治理方面具有一定的借鉴价值。

A Fast Predicting Neural Fuzzy Model for Suspended Solid Removal Efficiency in Multimedia Filter

Modeling of filter performance is very difficult because of complexity of the defining physical and chemical events in the filtration system whereas the knowledge of functionality of filter coefficient. The main objective of this study is to predict the performance of multimedia filter and to evaluate both the initial and transient stage of suspended solid removal efficiency depending on experimental data. Fuzzy logic has been used to build a model of multi input and one output (MISO) for the removal efficiency of multimedia filter which it consists from sand and granular activated carbon (GAC) mediums. The control parameters of (FLC) of Sugeno model are seven parameters which are media depths, media grains size for both sand and GAC, filtration rate, diameter of suspension particle, feed concentration, and operation time. The output parameter is removal efficiency of media filter whereas these data are collocated from pilot scale deep bed filter, thus, the removal efficiency of filter was modeled by 575 rules as a function of different control parameters. An adaptive of neuron fuzzy inference system (ANFIS) had used to simulate the experimental data. The simulation results were evaluated using mean absolute percentage error (MAPE), whereas the results showed that the prediction of ANFIS model has a good agreement with experimental data when the MAPE is equal to 7.0458 and fuzzy rule -based modeling proved a reliable and flexible tool to study the performance of multimedia filter. The conclusion showed that there is a relationship between flow rate, effective size and optimum bed depth for all filter media, the increment of effective size generates a higher value of optimum filter bed depth for a lower value of filtration rate. It was concluded that the optimal removal efficiency (95-100) achieved by (0.5-0.7 mm) grain size of sand, (1.5-1.9) mm grain size of granular activated carbon (GAC), with media depths should range from 0.3 to 0.6 m.

A study on effects of ceramic foam filter on flow aspect through water modeling experiment

Casting defects that are closely related to entrapped air bubbles and metallic oxides occur very frequently in the sand mold casting process. Many researchers have shown that these defects can be reduced by adopting an appropriate gating system design. However, it is difficult for field engineers to identify a specific gating system that is more appropriate for their products. In this study, we tried to draw a comparison between two gating system designs with and without a ceramic foam filter. The ceramic foam filter was added to the horizontal runner just after the down sprue to prevent air bubble generation and reduce turbulence without a change of gating system design. The water modeling experiment was conducted with four different amounts of the initial volumes of water in the reservoir to verify the effects of initial pouring velocity. The results of the experiment applying the filter showed remarkably changed flow characteristics. The use of the filter was found to convert the flow pattern of water in the desired direction. The ceramic foam filter performed well to reduce flow velocity and stabilize the water stream.The flow pattern without a filter can be improved significantly even with the the use of just a 10 PPI irregular filter. Although the study confirmed that use of the filter may change the flow characteristics, it needs to be noted that the use of the ceramic filter alone cannot solve all the problems caused by a poorly designed gating system.