A novel design for anaerobic chemical oxygen demand and nitrogen removal from leachate in a semiaerobic landfill

The removal capacity of carbon and nitrogen from an artificial leachate was evaluated by using laboratory-scale columns, and a design was proposed to remove nitrogen more efficiently from a semiaerobic landfill. Five columns (i.e., two artificial municipal waste columns under anaerobic and semiaerobic conditions, an artificial construction waste column under semiaerobic conditions, and two crushed stone columns under anaerobic and semiaerobic conditions) were used. The influent load rates of organics [g chemical oxygen demand (COD)/m3 x day], NH4+, NO3- and aeration conditions for the columns were varied, and the removal capacities of the columns for COD, NH4+-N, and NO3--N were measured. Among the packed column materials, crushed stone was shown to be most effective in removing COD, NH4+ N, and NO3--N from artificial leachate. Average removal rates of crushed column under the semiaerobic condition (column D) for COD and NH4+-N were estimated at about 150 g COD/m3 x day and 20 g COD/m3 x day, while those of crushed column under anaerobic condition (column E) for COD and NO3--N at about 400 and 150 g COD/m3 x day, respectively. It also was found that denitrification and nitrification reactions in column D occurred at the same time, and the ratio of denitrification to nitrification was estimated to be about 80%. Therefore, an anaerobic structure, which could be attached to the bottom of a main pipe in a semiaerobic landfill, is suggested to remove nitrogen and organic substances more effectively.     

ANAMMOX与反硝化协同作用及氮素负荷研究

向成功启动并稳定运行630 d后的UASB生物膜反应器系统连续添加有机物,分析其对厌氧氨氧化反应脱氮效果的影响,并进行氮素浓度负荷试验.在厌氧氨氧化反应器系统中连续投加有机COD(葡萄糖),系统运行稳定,有机COD(葡萄糖)存在对系统去除氮素能力影响不大,有机COD去除率达到92.0%,仅用23 d,在同一反应器系统中成功实现了厌氧氨氧化与反硝化协同作用脱氮.氮素浓度负荷试验阶段,进水氨氮(NH 4-N)、亚硝氮(NO-2-N)以及总氮(TN)浓度负荷分别从0.063 kg/(m3·d)和0.063 kg/(m3·d)和0.126 kg/(m3·d)提升到了0.239 kg/(m3·d)、0.315 kg/(m3·d)和0.554 kg/(m3·d),相应去除率分别为84.0%、93.0%和85.0%,厌氧氨氧化工艺的UASB生物膜反应器对氮素浓度负荷仍有很大提升空间.     

溅水充氧生物滤池处理农村污水的研究

开发了一种处理农村污水的低能耗地埋式一体化溅水充氧生物滤池装置,通过拔风和溅水复合充氧技术实现了大幅度节能条件下的好氧生物处理.考察了在不同水力负荷及COD、NH4 -N容积负荷条件下本装置的处理效果,结果表明,在水力负荷小于10 m3/(m2·d)、COD及NH4 -N容积负荷分别小于0.3 kg COD/(m3·d)和0.08 kg NH4 -N/(m3·d)的条件下,可以取得较高的去除效果和良好的出水水质,COD、NH4 -N和TN的平均出水浓度分别为58.94 mg/L、2.78 mg/L和8.23 mg/L,平均去除率分别为51.7%、86.4%和70.6%.     

The Statistical Form for the Ambient Participate Standard Annual Arithmetic Mean vs Annual Geometric Mean

Abstract

The long-term stability of a biofilter loaded with waste gases containing NH₃ concentrations larger than 100 ppmv was studied in a laboratory-scale compost reactor. At an empty bed residence time (τ) of 21 sec, elimination capacities of more than 300 g NH₃/m³/day were obtained at elimination efficiencies up to 87%. Because of absorption and nitrification, almost 80% of the NH₃-N eliminated from the waste gas could be recovered in the compost as NH₄+-N or NO₂ ^?/NO₃ ^?-N. The high elimination capacities could be maintained as long as the NH₄+/NO_x concentration in the carrier material was less than 4 g NH₄+/NO_x ^?-N/kg wet compost. Above this critical value, osmotic effects inhibited the nitrifying activity, and the elimination capacity for NH₃ decreased. To restore the biofilter performance, a carbon source (methanol) was added to reduce NH₄+/NO_x ^? accumulated in the compost. Results indicate that methylotrophic microorganisms did convert NH₄+/NO_x ^? into biomass, as long as the NO₃ ^? content in the compost was larger than 0.1 g NO₃ ^?-N/kg compost. Removal efficiencies of CH₃OH of more than 90% were obtained at volumetric loads up to 11,000 g CH₃OH/m³/day. It is shown that addition of CH₃OH is a suitable technique for regenerating the compost material from osmotic inhibition as a result of high NH₃ loading. The biofilter was operated for 4 months with alternating loading of NH₃ and CH₃OH.     

超声波-膜生物法联合处理垃圾焚烧厂渗滤液

采用超声波-膜生物法(MBR)联合处理垃圾渗滤液,探讨了超声波辐射时间和MBR的水力负荷对COD、NH3-N和TP去除的影响。结果表明,(1)超声波单独处理时,超声波辐射时间在30～90 s时,COD、NH3-N最大增加率分别34.31%、3.36%,而对TP的去除没有影响;(2)超声波-膜生物(MBR)联合处理时,超声波辐射时间为300 s,MBR的水力负荷为6.4 L/(m2.d)时,COD、NH3-N和TP的最佳去除率分别为92.20%、80.10%和91.12%;MBR的水力负荷为12.8 L/(m2.d),超声波辐射时间在5～20 min时,COD、NH3-N的最佳去除率分别为92.34%、79.93%,TP的浓度低于0.2 mg/L;MBR反应时间为7 h,超声波辐射时间为5～20 min,与未进行超声波辐射处理(超声波辐射时间为0 min)相比,COD、NH3-N的去除率增加了11.37%、15.26%;超声波预处理有助于提高后续MBR对COD、NH3-N的去除作用。     

海南火山岩滤料曝气生物滤池工艺优化研究

本研究基于上向流曝气生物滤池污水处理系统,研究了该工艺不同气水比、不同水力停留时间、不同滤料高度层、反冲洗强度对污染物的处理效能的影响。结果表明,气水比为4∶1、水力停留时间2 h时,BAF出水中COD、NH+4-N和SS指标达到最佳;沿程污染物去除率随着滤料层高度的增加逐渐增大,当滤料高度大于1.6 m时趋于稳定,COD、NH+4-N和SS平均去除率分别达到80%、99%和80.3%。建议曝气生物滤池的反冲洗推荐程序为:先气冲(18 L/(m2·s)),单独气洗2~3 min;再气冲(18 L/(m2·s))加水冲(5 L/(m2·s)),联合反冲洗3~5 min;最后水冲(5 L/(m2·s)),漂洗5~8 min。     

人工湿地植物泌氧与污染物降解耗氧关系研究

实验采用静态水培方法研究了香蒲(Typha orientalis)、芦苇(Phragmites australis)和水葱(Scirpus validus)3种常见湿地水生植物潜在泌氧能力、去污效果,并对水生植物泌氧量与污染物降解耗氧量进行了计算分析,从而阐明湿地植物泌氧与污染物降解耗氧之间的关系。结果表明,3种植物泌氧能力由大到小依次为:芦苇香蒲水葱,其中,芦苇比放氧速率、面积泌氧率均最高,分别为3.36 mg O2/(g.d)和4.35 g O2/(m2.d)。植物对湿地系统中污染物的去除有重要影响,各植物系统COD去除速率在3.46~3.77 g/(m2.d)之间;NH4+-N去除速率在0.07~0.13 g/(m2.d);TN去除速率在0.25~0.27 g/(m2.d);TP去除速率均为0.09 g/(m2.d);均好于无植物空白系统。计算表明,各植物体系泌氧量在0.48~0.55 g O2/d之间;各植物体系COD、NH4+-N耗氧量在0.41~0.46 g O2/d之间;植物净泌氧量在0.02~0.12 g O2/d之间。植物泌氧量与COD、NH4+-N耗氧量呈显著正相关关系。若应用人工湿地处理城镇生活污水,各植物体系COD最大去除负荷在3.81~4.35 g/(m2.d)之间,NH4+-N最大去除负荷在0.83~0.95 g/(m2.d)之间,最大水力负荷在1.65~1.89 cm/d之间。     

Ammonium,Nitrate and Nitrite Nitrogen and Nitrate Reductase Enzyme Activity in Groundnut (Arachis hypogaea L.) Fields After Diazinon,Imidacloprid and Lindane Treatments

Impacts of diazinon (O,O-diethyl O-2-isopropyl-6-methylpyrimidin-4-yl phosphorothioate), imidacloprid [1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine] and lindane (1,2,3,4,5.6-hexachlorocyclohexane) treatments on ammonium, nitrate, and nitrite nitrogen and nitrate reductase enzyme activities were determined in groundnut (Arachis hypogaea L.) field for three consecutive years (1997 to 1999). Diazinon was applied for both seed- and soil-treatments but imidacloprid and lindane were used for seed treatments only at recommended rates. Diazinon residues persisted for 60 days in both the cases. Average half-lives (t_1/2) of diazinon were found 29.3 and 34.8 days respectively in seed and soil treatments. In diazinon seed treatment, NH₄ ⁺, NO₃ ^?, and NO₂ ^? nitrogen and nitrate reductase activity were not affected. Whereas, diazinon soil treatment indicated significant increase in NH₄ ⁺-N in a 1-day sample, which continued until 90 days. Some declines in NO₃ ^?N were found from 15 to 60 days. Along with this decline, significant increases in NO₂ ^?N and nitrate reductase activity were found between 1 and 30 days. Imidacloprid and lindane persisted for 90 and 120 days with average half-lives (t_1/2) of 40.9 and 53.3 days, respectively. Within 90 days, imidacloprid residues lost by 73.17% to 82.49% while such losses for lindane residues were found 78.19% to 79.86 % within 120 days. In imidacloprid seed-treated field, stimulation of NO₃ ^?N and the decline in NH₄ ⁺NO₂ ^?-N and nitrate reductase enzyme activity were observed between 15 to 90 days. However, lindane seed treatment indicated significant increases in NH₄ ⁺-N, NO₂ ^?-N and nitrate reductase activity and some adverse effects on NO₃ ^?N between 15 and 90 days.     

Biostyr曝气生物滤池处理城市污水的沿程生化特性

青岛市麦岛污水处理厂采用曝气生物滤池(BAF)处理城市污水,以稳定运行的Biostyr为研究载体,考察滤池COD、NH3-N、SS和细菌数量等生化特性的沿程变化.结果表明,在气水比为4∶1～5∶1、进水COD负荷为2.5 ～3.7 kg/(m3·d)、进水NH3-N负荷为0.18～0.57 kg/(m3·d)时,滤池对COD的降解主要在150 cm填料以下处,COD的去除率可达58.9％;NH3-N去除率沿滤柱高度的变化与COD有所不同,在100 cm以下填料处,NH3-N的去除率仅为3.6％,在100 ～350 cm填料之间,NH3-N的去除率增加迅速,可达56.1％;对SS的去除主要发生在100 cm填料以下,去除率达51.7％.     

复合生物滤池处理城市高污染水体

采用中试规模复合生物滤池处理城市高污染水体,考察了滤池的最佳运行参数以及对氮和有机物的去除效果。结果表明:滤池容积负荷宜控制为0.3～0.5 kg COD/(m3.d),水力负荷4.5～5 m3/(m2.d),适宜的通风比为9%,当C/N为5～8时,滤池COD、NH4+-N和TN平均去除率分别为80%、83%和63%,达到高效同步硝化反硝化状态。     

Simultaneous nitrification and denitrification by Pseudomonas sp. Y-5 in a high nitrogen environment

Pseudomonas sp. Y-5, a strain with simultaneous nitrification and denitrification (SND) capacity, was isolated from the Wuhan Municipal Sewage Treatment Plant. This strain could rapidly remove high concentrations of inorganic nitrogen. Specifically, Pseudomonas sp. Y-5 removed 103 mg/L of NH₄⁺-N in 24 h without nitrate or nitrite accumulation when NH₄⁺-N was its sole nitrogen source. The NH₄⁺-N removal efficiency (RE) was 97.26%, and the average removal rate (RR) was 4.30 mg/L/h. Strain Y-5 also removed NO₃^?-N and NO₂^?-N even in aerobic conditions, with average RRs of 4.39 and 4.23 mg/L/h, respectively, and REs of up to 99.34% and 95.81% within 24 h. When cultured in SND medium (SNDM-1), strain Y-5 achieved an NH₄⁺-N RE of up to 97.80% and a total nitrogen (TN) RE of 93.01%, whereas NO₃^?-N was fully depleted in 48 h. Interestingly, high nitrite concentrations did not inhibit the nitrification capacity of Y-5 when grown in SNDM-2, the RE of NH₄⁺-N and TN reached 96.29% and 94.26%, respectively, and nitrite was consumed completely. Strain Y-5 also adapted well to high concentrations of ammonia (~401.68 mg NH₄⁺-N/L) or organic nitrogen (~315.12 mg TN/L). Our results suggested that Pseudomonas sp. Y-5 achieved efficient simultaneous nitrification and denitrification, thus demonstrating its potential applicability in the treatment of nitrogen-polluted wastewater.

     

SBR单级自养脱氮系统氮素转化途径

利用氮素计量关系和批式实验研究了SBR系统中基于短程硝化的单级自养脱氮特性和脱氮途径。结果表明,SBR系统获得良好脱氮效果,TN最高去除负荷和去除速率分别达0.49 kg N/(m3.d)和0.20 kg N/(kg VSS.d);系统中82%的氨氮转化成气体脱除,10%的氨氮转化成硝酸盐氮。批式实验结果表明,SBR系统中的污泥同时具有厌氧氨氧化、亚硝酸盐氧化和自养反硝化活性,三者的反应速率分别为0.12 kg NH4+-N/(kg VSS.d)、0.04 kg NO2--N/(kg VSS.d)和0.03 kg NO2--N/(kg VSS.d)。综上,SBR系统中氮的脱除是短程硝化、厌氧氨氧化和反硝化共同作用的结果,产生的硝酸盐是厌氧氨氧化和硝化作用所致。     

用微电极测定曝气量对SBR系统中硝化作用的影响

为了研究曝气量对硝化作用的影响,实验采用3个相同的SBR装置,分别在曝气量为4、10和16 L/h的条件下处理人工污水,并采用自制的溶解氧、NO3-、NH4+和pH微电极测定了活性污泥絮体内部微元环境中相应基质的浓度。结果表明,曝气量为4 L/h时,活性污泥絮体内存在厌氧微区,NO3--N浓度减小了,发生了反硝化作用;而曝气量为10 L/h和16 L/h时,活性污泥絮体内发生的都是硝化反应,且NH4+-N浓度的减小量、NO3--N浓度的增大量都随着曝气量的增大而增大,pH随着曝气量的增大而减小。     

焦化废水深度处理试验研究

采用BC法＋复合过滤技术工艺对焦化废水生化出水进行深度处理试验。结果表明，在SE混凝剂投药量为30 mg/L、BC池停留时间为1.5 h、复合过滤器水力负荷为2.4 m³/（m²·h）的条件下，当深度处理进水水质为COD＝196.1 mg/L、色度＝120倍、NH₃-N＝35.1 mg/L时，其去除率分别为74.7%、86.7%和69.7%，出水可达回用水要求。     

管道沉砂用作雨水花园土壤改良材料的可行性

以建筑黄砂为对照,采用排水管道清通作业产生的管道沉砂作为提高土壤渗透性能的改良材料,通过模拟土柱实验考察了雨水花园对路面径流污染的控制效果.实验结果表明,在装置初始运行阶段,模拟柱中污染物的淋出浓度迅速降低,污染地下水的风险很低;当污染物淋失达到稳定时,掺加同比例管道沉砂与建筑黄砂的模拟柱在提高土壤渗透速率方面效果相近,而对COD、TP、TSS、NH4+-N、NO3--N、重金属等污染物的去除两者效果则相差不大.结果表明,以管道沉砂作为土壤改良材料,在降低南方粘性土壤地区雨水花园的建造成本、实现废弃物的再利用方面具有良好前景.     

Evaluating Environmental Parameters for Minimum Ammonium Losses during Composting of Trimming Residues

Abstract

A neural fuzzy system was used to investigate the influence of environmental variables (time, aeration, moisture, and particle size) on composting parameters (pH, organic matter [OM], nitrogen [N], ammonium nitrogen [NH₄ ⁺-N] and nitrate nitrogen [NO₃ ^--N]). This was to determine the best composting conditions to ensure the maximum quality on the composts obtained with the minimum ammonium losses. A central composite experimental design was used to obtain the neural fuzzy model for each dependent variable. These models, consisting of the four independent process variables, were found to accurately describe the composting process (the differences between the experimental values and those estimated by using the equations never exceeded 5–10% of the former). Results of the modeling showed that creating a product with acceptable chemical properties (pH, NH₄ ⁺-N and NO₃ ^--N) entails operating at medium moisture content (55%) and medium to high particle size (3–5 cm). Moderate to low aeration (0.2 L air/min · kg) would be the best compromise to compost this residue because of the scant statistical influence of this independent variable.     

容积负荷对ANAMMOX生物滤池脱氮效能的影响及其基质动力学

采用2套启动成功的上向流厌氧氨氧化（ANAMMOX）生物滤柱，通过调节进水NaNO₂和（NH₄）₂SO₄ 的浓度负荷及水力负荷，改变进水容积负荷，探讨容积负荷对ANAMMOX生物滤柱脱氮效能的影响及其动力学模型。结果表明，滤速恒定条件下，通过提高进水基质浓度来提高进水TN容积负荷，其容积负荷去除动力学过程符合Monod-Haldane基质抑制模型。进水NH₄⁺-N与NO₂^--N浓度分别低于100 mg/L和133 mg/L时，反应器脱氮效果不受明显影响，TN容积去除负荷可达4.21 kg/（m³·d），TN去除率可达80%以上。进水基质浓度恒定条件下，通过提高滤速来提高进水TN容积负荷，其容积负荷去除动力学过程符合零级动力学方程。不受基质浓度抑制的条件下，滤速为3.0 m/h、进水容积负荷为8.82 kg/（m³·d）时，反应器总氮容积负荷去除量可达7.15 kg/（m³·d），总氮去除率可达81.1%。     

平板膜-生物反应器净化微污染水源水的研究

利用平板膜-生物反应器恒流运行处理微污染水源水,考察通量为18、25及30 L/m2·h时其运行特性及有机物和氨氮的去除效果.结果表明:3个工况对COD的去除率分别为78.7%、76.9%和80.4%,出水COD低于15 mg/L;3个工况对NH4 -N的去除率分别为90.4%、87.4%和92.8%,出水NH4 -N低于0.5 mg/L;3个工况对UV254的去除率分别为27.5%、28.2%和48.1%.胞外聚合物(EPS)的研究结果表明,其与膜污染之间并没有显著关系,运行通量的选择是影响膜污染和操作运行的一个重要原因.     

土壤渗滤介质系统去除雨水径流污染物

利用昆明当地的土壤在室内填装一个土柱渗滤系统，使用配水浓度模拟昆明市区雨水径流污染物浓度，进行去除雨水径流污染物的实验研究，考察系统对COD、TN、NH4＋、NO3^-、NO2^-和TP的去除效果。实验结果表明，该土壤渗滤系统对COD平均去除率为82．04％，对TN的平均去除率为22．64％，对NH；平均去除率为94．26％，但是对NO3^-、NO2^-去除效果较差，对TP平均去除率为96．95％；另外，系统长期运行导致下渗速度降低，出水效果反而变好。     

垃圾渗滤液处理工艺运行参数优化与技术比较

垃圾渗滤液是公认的一种成分复杂且难以处理的高浓度有机废水,笔者在北京市海淀区六里屯垃圾填埋场通过2007—2010年垃圾渗滤液处理的工程实践,以COD和氨氮的去除率为指标,研究了不同的垃圾渗滤液处理工艺组合,以及不同运行参数条件下对垃圾渗滤液的处理效果。结果表明,在中温UASB和A/O的平均水力停留时间(HRT)缩短1/3的情况下,通过改进A/O段曝气方式,优化系统的pH、DO等运行参数,用MBR替代絮凝工艺,使整个组合工艺对COD的年平均去除率达到了94.3%,氨氮的去除率维持在99.5%以上,出水氨氮稳定在10 mg/L以内,而改造前的COD与氨氮的年平均去除率仅为82.2%与55.3%。与改造前的UASB+A/O+絮凝工艺组合相比,改造后的UASB+A/O+MBR工艺组合具有更高的污染物去除能力、更好的抗缓冲性和稳定性。