印染废水处理厂的生物除臭研究

针对印染废水处理厂的典型废气,开展了生物滴滤池净化工艺和技术的研究,详细分析了不同填料、温度、营养液等工艺条件对生物滴滤池处理性能的影响,确定了合适的生物滴滤池运行工艺及参数。试验结果表明,设备对H2S的最大去除负荷为50 g/(m3.h),当进气浓度<200 mg/m3时,生物滴滤池对H2S的去除率稳定在95%以上,且碳质生物酶填料具有比表面积大、易于微生物附着、抗冲击负荷性强等特性。根据吸附-生物膜理论,验证了生物滴滤池降解低浓度H2S废气动力学模型的有效性。     

间歇曝气连续回流生物膜工艺处理农村生活污水

针对农村生活污水的特点,在厌氧—3级好氧/缺氧生物膜工艺的基础上开发出间歇曝气连续回流生物膜工艺,并考察了该工艺的实际处理效能。系统实际处理量为48 m3/d,HRT为1.5 d,水解酸化段的水力负荷为0.88 m3/(m3·d),填料装填率为60%;接触氧化段的水力负荷为4.57 m3/(m3.d),填料装填率为75%。系统稳定运行6个月的结果表明:该工艺对COD、BOD5、NH3-N、TP和SS的平均去除率分别为74.8%、83%、51.4%、60.3%和81.8%,以上指标的平均出水浓度分别在57、14.3、19、2.48、24 mg/L以下,达到了天津市农村污水处理厂排水标准(DB 12/356—2008)的要求,可作为农业灌溉等农业生产性用水。     

A/O生物膜工艺处理煤气废水的试验研究

采用A/O生物膜工艺处理煤气废水,考察了污泥负荷、硝化负荷、硝化液回流比及污泥龄对处理效果的影响.结果表明,A/O生物膜工艺可有效去除煤气废水中的NH4+-N和有机物.当进水COD为2 000 mg/L、进水流量为0.5 m3/h、硝化液回流比为4、污泥龄为30 d、污泥负荷为0.8 kgCOD/(kgVSS·d)、硝化负荷为0.08 kgNH4+-N/(kgVSS·d)时,系统稳定运行2个月后,出水的COD、BOD5、NH4+-N浓度分别为157、4.9、12.5 mg/L,去除率分别为92%、99%和93%.     

水解/接触氧化/BAF/O_3/BAC工艺处理采油废水

采油废水属于污染物浓度高、成分复杂、较难处理的工业废水,难以用单一的处理技术净化。采用"水解/接触氧化/BAF/O3/BAC"组合工艺对大港油田港东污水处理站的隔油池出水进行处理,当水解池的HRT为15 h时,对COD的平均去除率为28.7%,且此时的可生化性改善程度最好,出水平均B/C值达到0.40,提高了37.9%;接触氧化池的最佳停留时间为7.50 h,容积负荷为0.62 kg COD/(m3·d),此时对COD的去除率达到19.3%;BAF的最佳停留时间为1.46 h,容积负荷为2.55 kg COD/(m3·d),此时对COD的去除率为20.6%;在O3/BAC工段,当O3投加量为19.5 mg/L时,其发挥作用最佳。BAC单元抗冲击负荷能力较强,在负荷为1.61~2.78 kg COD/(m3·d)条件下,其出水水质都较好;在最佳试验条件下,经该组合工艺处理后的出水水质能稳定达到《天津市污水综合排放标准》(DB 12/356—2008)。     

O-A-O曝气生物滤池对COD和NH3-N去除效果的试验研究

O-A-O曝气生物滤池对COD和NH3-N的去除效果进行实验研究,并在各个阶段对比中找出最优的运行工况,从而达到节约能源,降低运行成本的目的。研究结果表明,在进水水力负荷为1m3/m·2h～3m3/m·2h、有机负荷为4kgCOD/(m·3d)～13kgCOD/(m·3d)及气水比1:1～4:1的工艺条件下、COD和NH3-N的去除率达到65%～81%和51%～74%。     

EGSB处理生活垃圾焚烧厂垃圾渗滤液的工程实践

采用EGSB厌氧反应器处理某生活垃圾焚烧厂垃圾渗滤液,设计处理能力为200m3/d,容积负荷为11.2 kg/(m3·d),单个反应器尺寸为9 m×25 m。运行数据表明,EGSB处理生活垃圾焚烧厂渗滤液具有很强的耐冲击负荷能力,运行过程中实际处理水量为50~305 m3/d、COD容积负荷为2~17.6 kg/(m3·d)、ALK为7 500~14 000 mg/L、VFA最高为7 284 mg/L、VFA/ALK为0.01~0.55,系统出水p H值7.7,COD去除率均较为稳定(80%~95%),出水COD稳定在1 500~2 000 mg/L。沼气产率为0.4~0.5 m3/kg COD,沼气中甲烷含量为71%~78%。     

溅水充氧生物滤池处理农村生活污水的优化研究

采用由缺氧池和溅水充氧生物滤池组成的一体化地埋式装置处理农村生活污水,考察了对有机物及氮、磷的去除效果,在此基础上重点分析了水力负荷及污染物容积负荷对处理效果的影响,并通过模拟试验探讨了溅水盘构造、设置方式等的优化设计方案.结果表明装置对COD的平均去除率为57.1%,对NH4 -N的平均去除率为86.4%,对TN的平均去除率达到了70.6%.为了保证良好的处理效果,应使COD容积负荷＜0.3 kgCOD/(m3·d),NH4 -N容积负荷＜0.08kgNH4 -N/(m3·d),水力负荷＜0.6 m3/(m2·h),且硝化液回流比设定为3较合理.在B型溅水盘的间距为30 cm的条件下,设置2层即可取得较好的充氧效果.     

水解酸化/MBBR工艺处理中药废水的中试研究

南京某制药厂拟采用水解酸化/移动床生物膜反应器(MBBR)工艺对中药废水处理工艺进行升级改造,为考察该工艺的可行性开展了中试研究.试验结果表明,当进水量为0.4 m3/h时,进、出水平均COD分别为1161 mg/L和167 mg/L,对COD的平均去除率为85.6%.一级MB-BR的最大容积负荷与最大去除负荷分别为6.64和5 kgCOD/(m3·d),两者的平均值分别为4.66和2.94 kgCOD/(m3·d),分别是现有生物接触氧化工艺的4.28倍和5.88倍.水解酸化池与厌氧池2对COD的去除率相当,而HRT不到厌氧池2的1/3,对COD的去除负荷与容积负荷分别是厌氧池2的4.28倍和3.84倍.     

UASB-A/O-UF工艺处理垃圾焚烧发电厂渗滤液

江苏某生活垃圾焚烧发电厂渗滤液处理工程采用UASB—A/O-UF工艺,对UASB反应器、A/O池和UF的运行效果进行了分析。当UASB反应器有机负荷约为7.1kgCOD/(m~3·d)时,COD去除率81%,A/O池中O池在DO为2~3mg/L、pH值为7.2~7.5、温度为31~33℃、有机负荷约为1.8 kgCOD/(m~3·d)时,对COD和氨氮的去除率分别为80%和98%以上,UF出水水质达到《污水综合排放标准》(GB 8978—1996)的三级标准。     

生物接触氧化/垂直流人工湿地处理城市生活污水

采用生物接触氧化和复合垂直流人工湿地的组合工艺处理城市生活污水,考察了对主要污染指标的去除效果.结果表明:与不曝气和连续曝气相比,在间歇曝气条件下,组合工艺对COD和氮的去除率较高.在进水负荷为0.8m3/(m2·d)、水力停留时间为1d、曝气量为4.038m3/(m2·d)、曝气/停曝周期为20 min/60 min的条件下,组合工艺对COD、NH4+-N、TN的去除率分别为80.37％、98.32％、80.22％,出水COD、NH4+-N、TN浓度均达到了《城镇污水处理厂污染物排放标准》(GB 18918-2002)的一级A标准.     

滴滤池-人工湿地组合工艺处理农村生活污水

采用滴滤池-人工湿地组合工艺处理农村生活污水,考察了其除污效果及两工艺对污染物去除的贡献率.中试结果表明,在稳定运行状态下,滴滤池对COD、氨氮、总氮和总磷去除的贡献率分别为74.5%、79.2%、33.8%、47.5%,人工湿地的则分别为25.5%、20.8%、66.2%、52.5%.滴滤池能有效完成对有机物的降解和硝化作用,人工湿地系统则能进一步去除氮、磷等污染物,两者结合可使污水中的各类污染物得到有效去除.     

An energy-efficient two-stage passively aerated trickling filter for high-strength wastewater treatment and reuse

This work aimed to assess the technical and energetic feasibility of a passively aerated laboratory-scale trickling filter, configured as a two-stage system, to produce urban wastewater (UWW) reusable in agriculture. The trickling filter was fed continuously with high-strength UWW at four hydraulic retention times (HRTs), that is, 10, 5, 2 and 1 day, corresponding to organic loading rates (OLRs) of 0.1, 0.2, 0.5 and 0.9 kg COD/m³/d, respectively. The results revealed a good performance in organic load removal and nitrification at the four HRTs. The trickling filter showed high organic pollutant removal efficiencies of up to 93%, 94% and 98% for chemical oxygen demand (COD), BOD₅ and total suspended solid (TSS), respectively, as well as high ammonia nitrogen removal above 96% at the shortest HRT of 1 day. All physicochemical parameters were significantly lower than the allowable limits set out in ISO 16075 for category C (non-food crop irrigation) irrigation water. The reuse of treated UWW in irrigation led to germination indexes and growth parameters of triticale (Triticosecale Wittm.) almost equal to those obtained using tap water. Energy use was found to be about 0.2754 kWh/m³ of treated wastewater, making it competitive with trickling filter plants reported in the literature. The simplicity and energy efficiency of the developed trickling filter system, combined with its capacity for almost full nitrification, make it appealing for sewage treatment in small communities in developing countries.     

Effect of mass transport on BOD removal in trickling filters

The effect of liquid-phase mass transport on BOD removal efficiency in a trickling filter is presented based on an analytical model of the process. It is shown graphically that liquid-phase mass transport resistances can significantly affect BOD removal for a given trickling filter. The applicability of the results presented to the analysis of experimental data and trickling filter design is discussed.     

The removal of pharmaceuticals, personal care products, endocrine disruptors and illicit drugs during wastewater treatment and its impact on the quality of receiving waters

A 5-month monitoring program was undertaken in South Wales in the UK to determine the fate of 55 pharmaceuticals, personal care products, endocrine disruptors and illicit drugs (PPCPs) in two contrasting wastewater plants utilising two different wastewater treatment technologies: activated sludge and trickling filter beds. The impact of treated wastewater effluent on the quality of receiving waters was also assessed.PPCPs were found to be present at high loads reaching 10 kg day⁻¹ in the raw sewage. Concentrations of PPCPs in raw sewage were found to correlate with their usage/consumption patterns in Wales and their metabolism. The efficiency of the removal of PPCPs was found to be strongly dependent on the technology implemented in the wastewater treatment plant (WWTP). In general, the WWTP utilising trickling filter beds resulted in, on average, less than 70% removal of all 55 PPCPs studied, while the WWTP utilising activated sludge treatment gave a much higher removal efficiency of over 85%. The monitoring programme revealed that treated wastewater effluents were the main contributors to PPCPs concentrations (up to 3 kg of PPCPs day⁻¹) in the rivers studied. Bearing in mind that in the cases examined here the WWTP effluents were also major contributors to rivers' flows (dilution factor for the studied rivers did not exceed 23 times) the effect of WWTP effluent on the quality of river water is significant and cannot be underestimated.     

Occurrence of organic wastewater compounds in effluent-dominated streams in Northeastern Kansas

Fifty-nine stream-water samples and 14 municipal wastewater treatment facility (WWTF) discharge samples in Johnson County, northeastern Kansas, were analyzed for 55 compounds collectively described as organic wastewater compounds (OWCs). Stream-water samples were collected upstream, in, and downstream from WWTF discharges in urban and rural areas during base-flow conditions. The effect of secondary treatment processes on OWC occurrence was evaluated by collecting eight samples from WWTF discharges using activated sludge and six from WWTFs samples using trickling filter treatment processes. Samples collected directly from WWTF discharges contained the largest concentrations of most OWCs in this study. Samples from trickling filter discharges had significantly larger concentrations of many OWCs (p-value<0.05) compared to samples collected from activated sludge discharges. OWC concentrations decreased significantly in samples from WWTF discharges compared to stream-water samples collected from sites greater than 2000 m downstream. Upstream from WWTF discharges, base-flow samples collected in streams draining predominantly urban watersheds had significantly larger concentrations of cumulative OWCs (p-value=0.03), caffeine (p-value=0.01), and tris(2-butoxyethyl) phosphate (p-value<0.01) than those collected downstream from more rural watersheds.     

Characteristic evaluation of trickling filter process

Making rational assumptions concerning the biochemical reactions on the microbiological film attached to filter media, a method to predict the fraction of BOD removed of the wastewater is proposed. Effective first-order rate constants, multiplied by the active fraction of the biofilm surface on filter media, are correlated with liquid flow rate, specific surface area of the media, initial BOD in liquid and temperature by analyzing previously reported dataUsing the correlation obtained, the operating characteristics of both standard and high-rate trickling filters are quantitatively evaluated under various operating conditions and discussed. The application of trickling filter is best limited to rather low BOD loading conditions, because of its low BOD removal rate per unit power consumption at high BOD loading.     

Treatment of low strength domestic wastewater using the anaerobic filter

A laboratory scale anaerobic filter packed with synthetic high surface area trickling filter media was used to treat a low strength domestic wastewater averaging 288 mg 1⁻¹ COD. The filter was operated for 60 days after reaching steady-state at 20, 25, 35°C at a loading rate of 0.02 lb COD ft⁻³ day⁻¹ and 24 h hydraulic retention time. Filter effluent BOD₅ averaged 38 mg 1⁻¹ providing an average removal rate of 79%, and effluent COD averaged 78 mg 1⁻¹, corresponding to a 73% removal rate. Removal efficiencies showed very little sensitivity to daily fluctuations in influent wastewater quality. The filter performance at 25 and 35°C was not significantly different, but BOD and TSS removal efficiency declined a: 20°C. Gas production averaged 0.027 ft⁻³ of gas per ft³ of influent wastewater, or 1.875 ft³ of gas per pound of influent COD. Gas composition averaged 30% nitrogen, 65% methane, and 5% carbon dioxide. Ammonia nitrogen and sulfides both increased during treatment. It is concluded that the anaerobic filter is a promising candidate for treatment of low strength wastewaters and that post treatment for sulfides and ammonia may be necessary.     

Fate of dissolved organic nitrogen in two stage trickling filter process

Dissolved organic nitrogen (DON) represents a significant portion of nitrogen in the final effluent of wastewater treatment plants (WWTPs). Biodegradable portion of DON (BDON) can support algal growth and/or consume dissolved oxygen in the receiving waters. The fate of DON and BDON has not been studied for trickling filter WWTPs. DON and BDON data were collected along the treatment train of a WWTP with a two-stage trickling filter process. DON concentrations in the influent and effluent were 27% and 14% of total dissolved nitrogen (TDN). The plant removed about 62% and 72% of the influent DON and BDON mainly by the trickling filters. The final effluent BDON values averaged 1.8 mg/L. BDON was found to be between 51% and 69% of the DON in raw wastewater and after various treatment units. The fate of DON and BDON through the two-stage trickling filter treatment plant was modeled. The BioWin v3.1 model was successfully applied to simulate ammonia, nitrite, nitrate, TDN, DON and BDON concentrations along the treatment train. The maximum growth rates for ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria, and AOB half saturation constant influenced ammonia and nitrate output results. Hydrolysis and ammonification rates influenced all of the nitrogen species in the model output, including BDON.     

Field evaluation of the treatability of type A zeolite in a trickling filter plant

Type A zeolite is a synthetic aluminosilicate which can be used as a builder in laundry detergents. The treatability of this zeolite in wastewater was evaluated in a trickling filter plant under field conditions. The normal performance of the plant was established during a baseline period of three months, after which the zeolite was added to the raw wastewater for 7 months. The removal of the zeolite by the plant averaged 81% or more at an influent concentration of 10 mg 1⁻¹. Of the zeolite that passed into the secondary effluent, 92% was removed by a dual-media filter. Removal from raw influent to tertiary effluent was thus 99%. The presence of the zeolite in the wastewater had no effect on the performance of the plant, the production of gas by the anaerobic digester or the concentrations of Pb, Zn and Ni in the effluent.     

Effects of recirculation rate of nitrified liquor and temperature on biological nitrification–denitrification process using a trickling filter

In the modified Ludzack–Ettinger process, high‐energy input is required in a nitrification tank. To address this issue, a new biological nitrification–denitrification system was constructed with a trickling filter for nitrification. The effects of recirculation rate of nitrified liquor and temperature through the treatment of municipal wastewater were evaluated. The highest DN removal efficiency was observed at 6.5 h of hydraulic retention in the denitrification tank and 350% of recirculation rate of nitrified liquid against the influent flow rate. The DN removal efficiencies did not reach theoretical values for all conditions tested because the COD/N ratios in the influent often decreased to less than 5 g‐COD/g‐N and temperatures dropped to less than 15°C in winter. The former inhibited the denitrification process and the latter significantly decreased the bioactivity of nitrifying bacteria. As such, this system is suitable in tropical and subtropical areas with annual minimum temperatures of over 15°C.