Fenton-混凝法预处理垃圾渗滤液工艺研究

采用Fenton-混凝法对重庆市垃圾填埋场的垃圾渗滤液进行预处理。通过响应面优化设计Fenton氧化处理垃圾渗滤液工艺,建立Box-Behnken数学模型,考察了pH、H_2O_2投加量和FeSO_4·7H_2O投加量对垃圾渗滤液化学需氧量(COD)的影响。结果表明:在pH、H_2O_2投加量和FeSO_4·7H_2O投加量分别为3.2、1.1%、0.4%时,Fenton法预处理垃圾渗滤液的最佳COD去除率为59.06%。     

响应面法优化Fenton工艺处理反渗透浓缩液

采用Fenton工艺处理垃圾渗滤液处理过程中产生的反渗透浓缩液,应用BBD实验设计建立数学模型,以COD去除率、UV_(254)去除率和色度去除率为考察指标进行响应面分析,研究各因素及因素间的交互作用对响应值的影响。结果表明,根据COD最大去除率预测模型优化的组合条件为:初始pH值为5.08、H_2O_2投加量为19.53 mmol/L、[Fe⁽²⁺⁾]/[H_2O_2]为0.59,COD去除率为48.34%,UV_(254)去除率为51.48%,色度去除率为76.99%。最终通过模型验证,说明采用响应面法优化Fenton处理垃圾渗滤液反渗透浓缩液是可行的。     

响应面法优化Fenton工艺处理反渗透浓缩液

采用Fenton工艺处理垃圾渗滤液处理过程中产生的反渗透浓缩液,应用BBD实验设计建立数学模型,以COD去除率、UV_(254)去除率和色度去除率为考察指标进行响应面分析,研究各因素及因素间的交互作用对响应值的影响。结果表明,根据COD最大去除率预测模型优化的组合条件为:初始pH值为5.08、H_2O_2投加量为19.53 mmol/L、[Fe~(2+)]/[H_2O_2]为0.59,COD去除率为48.34%,UV_(254)去除率为51.48%,色度去除率为76.99%。最终通过模型验证,说明采用响应面法优化Fenton处理垃圾渗滤液反渗透浓缩液是可行的。     

O_3-H_2O_2与活性炭负载TiO_2预处理晚期垃圾渗滤液

采用O_3-H_2O_2高级氧化结合催化O_3氧化技术对晚期垃圾渗滤液进行预处理,考察了颗粒活性炭负载二氧化钛(TiO_2/GAC)催化剂的催化效果,并研究了反应体系中O_3和H_2O_2投加量以及pH等因素对COD去除效果的影响.结果表明,当O_3投加量为1.8 g·L~(-1),H_2O_2投加量为0.27 g·L~(-1),催化剂投加质量分数为15%时,反应90min的COD去除率达到40%;对出水调节pH≥11.4,经过沉淀后,COD去除率提高到58%.出水澄清透明,BOD5/COD从＜0.1提高到0.26.水质得到较大改善,可生化性明显提高,为后续的生化处理工艺起到较好的预处理作用.     

O3/H2O2高级氧化技术对实验室有机废水处理研究

O_3/H_2O_2高级氧化技术具有氧化能力强和无选择性等优点,被广泛用于高浓度、难降解和有毒有害的有机废水处理。考察了O_3/H_2O_2高级氧化技术在不同的处理条件(臭氧投加量、H_2O_2投加量、p H值、反应时间)下对实验室高浓度有机废水中COD的去除率影响,并通过页岩气采出水验证,结果表明:当臭氧投加量为40 mg·L~(-1)、双氧水投加量为0. 7 mg·L~(-1)、p H值为5、反应时间为40 min时,其COD去除率达90. 41%,可排入城市管网;在相同条件下处理COD浓度为1426 mg·L~(-1)的页岩气采出水,COD去除率达88. 3%。     

多元协同高级氧化技术处理垃圾渗滤液实验研究

以混凝-铁炭微电解-芬顿高级氧化工艺对垃圾渗滤液进行深度处理。探究了混凝剂投加量、微电解时间及H_2O_2投加量等因素对COD去除效果的影响。在PAC投加量为1 400 mg/L,PAM投加量为800 mg/L,铁炭微电解时间为3 h,H_2O_2的投加量为4 mL/L的条件下,垃圾渗滤液的COD整体去除率在84.7%左右,溶液的色度明显减小,有利于后续的生化处理。     

铁炭微电解-Fenton-生物接触氧化法处理土霉素废水

采用了铁炭微电解-Fenton-生物接触氧化工艺对高浓度难生化处理的土霉素废水进行处理.结果表明,当原水COD在6 000 mg·L~(-1)左右、pH=2.2时,铁炭微电解反应50 min后COD的去除率达到40%,再对铁炭微电解出水投加质量浓度220mg·L~(-1)的H_2O_2(30%)进行Fenton试剂法处理,COD的去除率达到75%以上,然后进入生物接触氧化反应池,出水能够达到排放标准.     

Al2O3/氧化石墨烯对老龄垃圾渗滤液的处理效能分析

垃圾渗滤液是一种难以降解的成分复杂的高浓度有机废水,通过常规的方式难以处理,尤其伴随着填埋年限的增长,渗滤液的组成和浓度也随之变化,针对这种情况,使用Al_2O_3、氧化石墨烯以及Al_2O_3/氧化石墨烯复合催化剂对老龄渗滤液进行处理,分析处理效果的影响因素。结果表明:Al_2O_3/氧化石墨烯复合催化剂的处理效果最好,反应时间3 h、催化剂投加量为0.6(催化剂与渗滤液COD的质量比)为最佳试验条件。在最佳试验条件下,使用其对垃圾渗滤液原液进行高级催化氧化处理后,COD的去除率可达到87.46%,此时渗滤液出水COD为1 284.10 mg·L~(-1),出水NH_4~+-N为2 172.04 mg·L~(-1)。     

UV/H_2O_2高级氧化+MBR工艺处理垃圾渗滤液的研究

采取UV/H_2O_2+膜生物反应器组合工艺深度处理垃圾渗滤液,研究工艺对有机物及氨氮处理效果。结果表明,当工艺条件为双氧水投加量为2.1 g(H_2O_2)/g(COD),pH呈弱酸性,反应时间2 h、温度30℃左右时,UV/H_2O_2工艺处理效果好。MBR反应器对UV/H_2O_2工艺段出水中有机物的生化降解效果显著,出水有机物去除率稳定在80%以上。     

MFPAC强化混凝-改性矿化垃圾吸附处理垃圾渗滤液

采用纳米Fe_3O_4与聚合氯化铝(PAC)复配制备磁性复合絮凝剂MFPAC,利用MFPAC强化混凝-改性矿化垃圾吸附处理垃圾渗滤液。结果表明,MFPAC中适宜的前驱物质量比为m(Fe_3O_4)∶m(PAC)=1∶3,正交实验结果表明,m(Fe_3O_4)∶m(PAC)以及投药量对混凝效果有较为显著的影响,p H和沉淀时间对去除效果影响相对较小,MFPAC对COD和色度的去除效果均优于单独投加PAC,投加量为1.5 g/L时,COD和色度去除率分别达到62.6%和66.5%;采用焙烧法对矿化垃圾进行改性,利用改性矿化垃圾吸附MFPAC混凝出水,在焙烧温度为700℃,吸附剂投加量为40 mg/L的条件下,COD和氨氮的去除率分别为56.7%和68.4%;MFPAC混凝-矿化垃圾吸附联合工艺对垃圾渗滤液COD、色度和氨氮的去除率分别为83.8%、78.5%和74.3%。     

Electrochemical peroxidation of contaminated aqueous leachate

The landfill process for disposal of domestic waste produces a large volume of contaminated aqueous leachate. This study was aimed at investigating the feasibility of using electrochemical peroxidation (ECP) for the treatment of this leachate. ECP is a process by which aqueous, or suspended organic matter, is oxidised by the action of hydroxyl free radicals, produced using hydrogen peroxide and cast iron or mild steel electrodes. The effectiveness of the ECP process was quantified by measuring reductions in leachate biological oxygen demand (BOD) and chemical oxygen demand (COD) as a result of treatment. Optimisation of the process was carried out by varying electrode voltage, polarity switching rate, leachate pH and hydrogen peroxide concentration. This resulted in an observed BOD reduction of 36% and COD reduction of 52%, which was achieved by adjusting the pH to 4.0, applying an electrode voltage of 1.9V and switching speed of 5 cycles per minute. The optimum hydrogen peroxide concentration was found to be 100ppm. In addition to reductions in BOD and COD, reductions in chloride and ammonium levels were measured and found to be 15% and 18% respectively. The results of the investigation indicate that the ECP process is effective in the treatment of landfill leachate, and suggest that with further optimisation, ECP may serve as an attractive alternative to current biological leachate treatment methods.     

PAC+FBR处理垃圾渗滤液的研究

由于垃圾渗滤液COD、NH4-N浓度高,并且含有重金属等有毒污染物,通常,单纯的生物处理方式效果并不理想.高COD浓度的垃圾渗滤液经混凝沉淀后,调节pH=12,进行氨吹脱,经此预处理后的垃圾渗滤液,进行Fed-Batch Reactor(FBR)好氧生物处理,比较投加粉末活性碳(PAC)和不投加两种情况下对COD和NH4-N去除效果.当PAC投加量为2 g/L时,COD去除率达86 %,NH4-N去除率达26 %.     

Combined adsorption and Chemical precipitation process for pretreatment or post-treatment of landfill leachate

Performances of combined adsorption and chemical precipitation were evaluated as one of the options for pretreatment or post-treatment of a municipal solid waste (MSW) landfill leachate and leachate from an industrial solid waste landfill. The COD and color removals of the leachate from a MSW landfill were 35% and 33% at an alum dose of 300 mg/L with preceding PAC (powdered activated carbon) dose of 200 mg/L, respectively. For MSW leachate, the combined adsorption and coagulation process showed 2.3 times higher COD removal at PAC dose of 200 mg/L and alum dose of 500 mg/L than the unit process of adsorption with poor settleability. The COD removal was accomplished mainly by adsorption, while coagulation was a key mechanism of color removal. The COD and color of the biologically treated leachate from an industrial solid waste landfill were removed up to 32% and 68%, respectively, at addition of 490 mgAlum/L and 1,000 mgPAC/L in adsorption-coagulation process with pH control. Combined adsorption and coagulation process with pH control showed better COD and color removal than the process without pH control. The color removal was influenced greatly by pH control, while COD removal was not. No difference in removal efficiency was observed between adsorption-coagulation and coagulation-adsorption. Maximum net increases in the COD and color removals by the adsorption-coagulation process were 40% and 46%, respectively, compared with the removals by sole chemical precipitation. The Freundlich isotherm exclusively described the adsorption of leachate components on the PAC. Thus, a combined adsorption and coagulation process was considered to be effective for pre-treatment or post-treatment of landfill leachate, and has distinct features of simple, flexible, stable and reliable operation against fluctuation of leachate quality and flowrate.     

微波强化Fenton氧化法对老龄垃圾渗滤液的处理试验

对预处理过的老龄垃圾渗滤液,进行微波强化Fenton氧化法试验,考察了该处理方法对垃圾渗滤液的作用效果并分析微波作用机理。结果表明:对厌氧/好氧工艺处理过的老龄垃圾渗滤液进行微波强化Fenton氧化法处理时,在最优处理条件下COD去除率可达75.6%以上;以负载Fe2+的颗粒活性炭(GAC)为催化剂替代Fe2+,在最优条件下处理,COD去除率可达87.1%以上。当预处理后的垃圾渗滤液中含有大量SO42-时,微波辐射会导致Fenton氧化法的处理效果降低。微波强化Fenton氧化法处理垃圾渗滤液只起到缩短处理时间的作用,并不能提高COD去除率。对NH3-N去除率在微波辐射条件下有所提高,但是效果并不明显。     

膜电生物反应器深度处理垃圾渗滤液研究

研究了管式膜膜电生物反应器对垃圾渗滤液的深度处理,考察膜电生物反应器的pH、水温、溶解氧和污泥浓度变化对垃圾渗滤液处理效果的影响,同时考察膜出水通量、COD和电导率.结果表明,采用膜电生物反应器进一步处理垃圾渗滤液,膜通量较稳定,出水COD(350～650mg·L~(-1))随原液COD(500～800 mg·L~(-1))呈大体相同趋势变化,在试验后期,COD去除率在25%～45%之间.     

Fenton试剂对垃圾渗滤液中腐殖质的氧化/混凝作用

采用Fenton试剂处理反渗透浓缩垃圾渗滤液,通过COD,TOC,UV254以及COD/TOC等表征手段考察氧化/混凝作用对COD和腐殖质去除效果的影响。结果表明,Fenton试剂对浓缩渗滤液中腐殖质去除（11.9 % ~ 89.5 %）高于总COD去除（9.6 % ~ 75.2 %）;渗滤液中腐殖质降解和COD去除具有较好的相关性。混凝作用（CODcoag,HScoag）受氧化作用（CODoxid,HSoxid）的影响并与之相反,氧化作用越大,混凝作用越小。(COD/TOC)oxid变化表明,在[H₂O₂]>80 mmol.L^-1,pH=2.0~4.0, [Fe ²⁺ ]=40~160 mmol.L^-1,反应时间2 h的实验条件下,渗滤液中有完全氧化过程发生,同时(COD/TOC)coag的变化说明经混凝作用去除的有机物氧化态高于其它实验区间。     

Effectiveness in the Removal of Organic Compounds from Municipal Landfill Leachate in Integrated Membrane Systems: Coagulation – NF/RO

The article presents the results of studies concerning the hydraulic permeability of integrated membrane systems during the treatment of municipal landfill leachate. The laboratory-scale experiments were conducted to determine the effectiveness of coagulation as a pretreatment option for treating stabilized landfill leachate and effectiveness of nanofiltration (NF) and reverse osmosis (RO) processes. The municipal landfill leachates were analyzed for the concentration of the following: polycyclic aromatic hydrocarbons (PAHs), nitrate nitrogen, ammonium nitrogen, chemical oxygen demand (COD), total organic carbon (TOC), total carbon (TC), suspended soils (SS), turbidity, pH. The commercially available coagulant – aluminum sulfate Al₂(SO₄)₃·18H₂O (alum) was used as a coagulant. The NF process was carried out at the transmembrane pressure of 1.5 MPa. The membrane separation process was based on a thin film membrane (DK). The transmembrane pressure of the RO stood at 2 MPa and for this process one polyamide membrane (AG) was used. The level of leachate treatment was defined for raw and cleaned wastewater indicators. Both NF and RO membranes allowed obtaining the high level of pollutants removal. In the coagulation–NF system, the removal efficiency was equal to 77% for PAHs, 88% for COD, 72% for ammonium nitrogen, 80% for nitrate nitrogen, 67% for TOC, 80% for TC, 96% for SS and during the RO – 86% for PAHs, 98% for COD, 93% for ammonium nitrogen, 87% for nitrate nitrogen, 89% for TOC, 100% for TC, 98% for SS. The calculations based on the assumptions of the mathematical filtration model (relaxation) made it possible to predict the efficiency of commercial filtration membranes used for leachate treatment.     

超声波协同电凝聚气浮法处理垃圾渗滤液的试验研究

分析了超声波在处理高浓度难降解有机物方面的优势及限制条件,提出利用超声波联合电凝聚气浮法处理晚期垃圾渗滤液工艺。试验研究分为单独超声波处理、单独电凝聚气浮处理以及超声波协同电凝聚气浮处理3个阶段。采用单因素分析法,揭示了反应时间、电凝聚电压、pH值、超声波功率和曝气方式对COD去除率的影响规律。得出最佳参数为反应时间30min,电凝聚电压12V,初始pH值为6.0,超声波辐照功率为125W,预先曝气20min。在此条件下,渗滤液中COD的质量浓度由822mg/L下降至232mg/L,COD去除率高达71.75%,而单独超声波和单独电凝聚气浮的去除率分别仅为15.74%、42.17%,从而验证了超声波技术与电凝聚气浮法联合处理有协同作用。     

电混凝-反渗透工艺处理垃圾渗滤液的试验研究

采用电混凝-反渗透组合工艺处理渗滤液经膜生物反应器的出水,考察组合工艺的处理效果及电混凝作为RO进水预处理的可行性。结果表明,组合工艺出水COD和NH3-N、TP的质量浓度分别为100 mg/L和20、0.2 mg/L,去除率分别达到95%、90%、98%,可以满足GB 16889-2008的排放要求;出水电导率为355μS/cm,膜出水电导率与进水电导率的比大于0.94。电混凝工艺能够有效降低RO进水的COD、TP含量,明显地减缓膜结垢污染,改善膜的产水率,可以作为膜前预处理。     

蒸发气相吸收耦合方法处理垃圾渗滤液

对垃圾渗滤液蒸发、蒸发-气相酸吸收、蒸发-气相碱吸收和蒸发-气相酸吸收-气相碱吸收处理进行了试验研究,考察了不同工艺真空度和渗滤液初始pH对冷凝液水质的影响。结果表明：采用蒸发法时,随着真空度的升高,冷凝液pH、NH₃-N浓度和总含盐量（TDS）值均呈下降趋势,而COD浓度逐渐增加。当初始渗滤液呈酸性时,冷凝液中NH₃-N的含量较低,而COD的含量较高;当初始渗滤液呈碱性时,冷凝液中COD的含量较低,而NH₃-N的含量较高。采用蒸发-气相酸吸收法可有效降低渗滤液中NH₃-N的含量,采用蒸发-碱吸收法可去除渗滤液中的COD。采用蒸发-气相酸吸收-气相碱吸收法能同时降低渗滤液中COD、NH₃-N和TDS的浓度,在渗滤液初始pH为8.1的条件下,对渗滤液中COD、NH₃-N和TDS的去除率均达99%以上,浓度分别降至60mg/L、8mg/L和10mg/L以下,冷凝液水质符合GB 16889—2008对环境敏感地区的排放标准。