Mg improves biomass production from soybean wastewater using purple non-sulfur bacteria

Soybean wastewater was used to generate biomass resource by use of purple non-sulfur bacteria (PNSB). This study investigated the enhancement of PNSB cell accumulation in wastewater by Mg^2 + under the light-anaerobic condition. Results showed that with the optimal Mg^2 + dosage of 10 mg/L, biomass production was improved by 70% to 3630 mg/L, and biomass yield also was improved by 60%. Chemical Oxygen Demand (COD) removal reached above 86% and hydraulic retention time was shortened from 96 to 72 hr. The mechanism analysis indicated that Mg^2 + could promote the content of bacteriochlorophyll in photosynthesis because Mg^2 + is the bacteriochlorophyll active center, and thus improved adenosine triphosphate (ATP) production. An increase of ATP production enhanced the conversion of organic matter in wastewater into PNSB cell materials (biomass yield) and COD removal, leading to more biomass production. With 10 mg/L Mg^2 +, bacteriochlorophyll content and ATP production were improved by 60% and 33% respectively.     

Mg2+ improves biomass production from soybean wastewater using purple non-sulfur bacteria

Soybean wastewater was used to generate biomass resource by use of purple non-sulfur bacteria(PNSB). This study investigated the enhancement of PNSB cell accumulation in wastewater by Mg2+under the light-anaerobic condition. Results showed that with the optimal Mg2+dosage of 10 mg/L, biomass production was improved by 70% to 3630 mg/L,and biomass yield also was improved by 60%. Chemical Oxygen Demand(COD) removal reached above 86% and hydraulic retention time was shortened from 96 to 72 hr. The mechanism analysis indicated that Mg2+could promote the content of bacteriochlorophyll in photosynthesis because Mg2+is the bacteriochlorophyll active center, and thus improved adenosine triphosphate(ATP) production. An increase of ATP production enhanced the conversion of organic matter in wastewater into PNSB cell materials(biomass yield) and COD removal, leading to more biomass production. With 10 mg/L Mg2+, bacteriochlorophyll content and ATP production were improved by 60% and 33% respectively.     

Cd2+ removal from wastewater by sulfate reducing bacteria with an anaerobic fluidized bed reactor

A process of treatment for containing Cd²⁺ wastewater by sulfate reducing bacteria with upflow anaerobic fluidized bed reactor has been studied. When the concentration of COD and Cd²⁺ in the influent were 270 5mg/L and 100mg/L respectively and hydraulic retention time was 4 hours, the removal rate of COD and Cd²⁺ were higher than 73 8% and 99 8% respectively. The reactor can treat as high as 1000mg/L of concentration of Cd²⁺ . The highest removal velocity rate of Cd²⁺ reached 2999 1mg/(L·d). And the possible relationship between sulfate reducing bacteria and methanogenic bacteria was discussed.     

Fe2+、Co2+、Ni2+对渗滤液厌氧过程的影响

通过单因素和正交试验,分别研究了Fe2+、Co2+、Ni2+及其组合对渗滤液厌氧过程中COD去除率和产甲烷量的影响.结果表明,分别投加Fe2+=25 mg·L-1、Co2+=1 mg·L-1、Ni2+=0.5 mg·L-1时对COD去除率和产甲烷量促进显著,3种微量元素均表现出了"低促高抑"的Hormesis效应.微量元素组合投加时,协同促进了甲烷的产生,其中Co2+是影响COD去除率的主要因素,Fe2+是影响产甲烷量的主要因素,但3种微量元素在其各自适宜的投加浓度范围时,对渗滤液厌氧过程的促进效果较为相近.各试验组的pH值维持在7.05~7.53之间,并与产甲烷量呈显著的相关关系.此外,渗滤液成分复杂,微量元素的生物有效性一定程度上受到限制,渗滤液厌氧体系对微量元素的需求较别的体系偏高.     

添加原水改善SBR工艺处理猪场废水厌氧消化液性能

采用序批式反应器(SBR)工艺直接处理猪场废水厌氧消化液,处理系统的效率较低,COD去除率仅有10%左右,NH₄⁺-N去除率70%左右;处理出水水质较差,出水COD高于1 000mg/L,出水NH₄⁺-N在200mg/L左右;处理系统的工作不稳定,效能逐渐恶化.在猪场废水厌氧消化液中添加部分未经厌氧消化的猪场废水(原水),处理系统的处理效率明显提高,COD去除率高于80%,出水COD降到250～350mg/L;NH₄⁺-N去除率高于99%,出水NH₄⁺-N小于10mg/L;处理系统的稳定性也得到增强.添加原水后,猪场废水厌氧消化液的BOD₅/COD比值从0.19上升到0.54,BOD₅/TN比值从0.28上升到2.04,增加了微生物生长和反硝化所需的碳源,强化了反硝化作用,不仅提高了总氮去除效率,而且通过回补碱度,维持了处理系统的pH值稳定.     

造纸废水曝气池中钙的去除及迁移转化规律研究

针对造纸废水好氧处理中钙离子（Ca²⁺）浓度过高影响生化过程和后续膜处理的问题,在实验室模拟废水曝气,研究Ca²⁺存在对COD去除效果的影响;对厌氧出水进行曝气实验,探究曝气量对钙去除效果的影响;分析表征造纸废水液相中Ca²⁺浓度和固相污泥中钙的形态,探究造纸废水曝气池中钙的迁移转化规律.结果发现：Ca²⁺的存在会影响活性污泥的活性,进而导致曝气过程中COD的去除率从71.76%降至36.94%;厌氧出水曝气初始阶段内曝气量越大,Ca²⁺的去除率越高;Ca²⁺浓度从厌氧出水到二沉池出水过程中逐渐下降,从游离态转变为CaCO₃的结合态而除去.     

Treatment of soybean wastewater by a wild strain Rhodobacter sphaeroides and to produce protein under natural conditions

The conventional treatment method of soybean wastewater is expensive and generates waste sludge that requires further handling. Purple nonsulfur bacteria (PNSB) wastewater treatment is a clean technology and can generate single cell protein while degrading pollutants. Awild strain of PNSB, Rhodobacter sphaeroides Z08, was isolated from local soil and was used to treat soybean wastewater. To develop a cost-effective process, the work was performed under natural conditions without artificial light, aeration, nutrients addition, or pH and temperature adjustment. The results showed that the wild strain Rhodobacter sphaeroides Z08 could grow well under natural conditions. The growth curve showed two quick-growth periods and a turning point. The Z08 treatment of soybean wastewater was zero order reaction and COD reduction was 96% after 10 d. The major byproducts of the process were C2–C5 organic acids, predominantly butyric acid. No alcohol was found in the effluent. The initial COD/bacterial-mass ratio (F/M) had a significant effect on soybean wastewater treatment efficiency. When the initial F/M was lower than 10 mg-COD/mg-bacteria, a sufficient amount of time to achieve 90% of COD reduction was only three days. The Z08 biomass yield was 0.28 g·g⁻¹, and the bacterial protein content was 52%.     

微生物燃料电池利用甘薯燃料乙醇废水产电的研究

利用空气阴极微生物燃料电池(MFC)处理甘薯燃料乙醇废水,以COD为5000mg/L的废水做底物,获得的最大电功率密度为334.1mW/m2,库仑效率(CE)为10.1%,COD去除率为92.2%.实验进一步考察了磷酸缓冲液(PBS)浓度和废水浓度对MFC产电性能的影响.PBS含量从50mmol/L增加到200mmol/L,MFC输出的最大电功率密度提高了33.4%,CE增加26.0%,但PBS对废水的COD去除率影响不大.含50mmol/LPBS的废水COD从625mg/L增加到10000mg/L,COD去除率和MFC输出的最大电功率密度在废水浓度为5000mg/L处均获得最大值,但CE值有降低的趋势,从28.9%变化至10.3%.这些结果表明,MFC可以在处理甘薯燃料乙醇废水的同时获得电能;增大PBS浓度能提高MFC的产电性能;MFC输出的最大电功率密度随废水COD增加而增大,但废水浓度过高会引起酸化使MFC产电性能下降.     

吸附-降解组合生物系统处理含铜离子城市污水

采用Pseudomonas putida 5-x细胞为吸附剂的生物吸附过程组合SBR生物降解系统处理含铜离子城市废水.研究了生物吸附剂Pseudomonas putida 5-x细胞的最佳制备条件以及组合系统的运行过程.实验结果表明,在优化的条件下,Pseudomonas putida 5-x细胞对铜离子的吸附容量可达87.3mg·g^-1,经生物吸附处理后,污水中Cu²⁺的含量显著降低,尽管残留的Cu²⁺对活性污泥吸附COD的能力尚有一定影响,但已不影响SBR系统对废水中COD的去除效果.研究表明,在活性污泥法处理含铜离子废水前,采用生物吸附技术降低废水中Cu²⁺含量,有利于提高后续活性污泥过程对COD的去除能力.     

Ca2+、Mg2+共存对SBR工艺生物脱氮和微生物群落结构的影响

为了研究共存的硬度金属离子在废水生物处理中的作用,在进水Ca~(2+)为1.1 mmol·L~(-1)的条件下,通过改变Mg~(2+)的浓度,考察Ca~(2+)/Mg~(2+)物质的量比对SBR工艺污染物去除和微生物群落的影响,采用高通量测序技术分析微生物优势种群的变化,以期从微生物角度明确Ca~(2+)、Mg~(2+)共存对生物脱氮的影响机制.结果表明:当Ca~(2+)/Mg~(2+)物质的量比分别为2、1和0.5时,COD去除率由88%分别升高至90%、91%和93%;NH~+_4-N去除率由74%分别升高至91%、93%和96%;TN去除率由44%分别升高至58%、62%和69%.随着进水Ca~(2+)/Mg~(2+)物质的量比的降低,微生物群落的丰富度升高,Ca~(2+)/Mg~(2+)物质的量比为2的微生物群落结构与Ca~(2+)/Mg~(2+)物质的量比为1和0.5的微生物群落结构差异显著.变形菌门、拟杆菌门和放线菌门一直为SBR工艺的优势菌门,有利于有机污染物的去除.参与脱氮过程的Niabella和Dechloromonas在反应器内富集,保证了良好的脱氮效果.Ca~(2+)/Mg~(2+)物质的量比的降低促进了有机物和总氮的去除及微生物多样性的提高.     

Nitrogen removal and simultaneous nitrification and denitrification in a fluidized bed step-feed process

For urban wastewater treatment, we conducted a novel four-stage step-feed wastewater treatment system combined with a fluidized bed laboratory experiment to investigate chemical oxygen demand (COD), NH₄⁺-N, and total nitrogen (TN) removal performance. The removal rates of COD, NH₄⁺-N and TN were 88.2%, 95.7%, and 86.4% with effluent concentrations of COD, NH₄⁺-N and TN less than 50, 8, and 10 mg/L, respectively. Biomass and bacterial activities were also measured, with results showing more nitrobacteria in the activated sludge than in the biofilm; however, bacterial activity of the biofilm biomass and the activated sludge were similar. Nitrogen concentrations during the process were also detected, with simultaneous nitrification and denitrification found to be obvious.     

UASB反应器处理维生素B12淀粉混合废水的研究

为考察厌氧技术处理维生素Ｂ１２淀粉混合废水的可行性,进行了采用ＵＡＳＢ反应器处理废水研究,结果表明,在中温条件下,当进水ＣＯＤ浓度为１００００－１２０００ｍｇ／Ｌ时,ＣＯＤ容积负荷可达到３０ｋｇ／（ｍ＾３．ｄ）,ＣＯＤ去除率为８０％,容积产气率为１６．８０ｍ＾３／（ｍ＾３．ｄ）。     

FCR多级接触氧化系统处理乳品工业废水的研究

为提高乳品工业废水生物处理的去污脱氮能力,以新型螺旋状纤维填料作为载体,采用多级氧化槽内不同种类微生物形成的食物链系统（food chain reactor）,详细考察了不同水力停留时间COD、TN、NH^＋₄-N、TP等的去除率及其去除机理,并对污泥减量化效果进行了初步探讨.结果表明,当进水COD为842～1 843 　mg/L、TN为36.3～92.2 　mg/L、NH^＋₄-N为30.1～52.1 　mg/L,HRT=6　h时,系统COD的平均去除率达到93.3%;TN和NH⁺₄-N的去除效果显著,其平均去除率分别达到73.3%和80.7%,出水COD、TN、NH⁺₄-N平均值分别为79.4　mg/L、9.6 　mg/L、6.1　mg/L,均低于《污水综合排放标准》（GB 8978-2002）的一级标准.该系统不仅具有较高的去污脱氮效果,而且产生的剩余污泥量极少,其污泥产率的平均值为7.7%.该系统运行费用低,操作管理方便,长期运行稳定,可应用于城市污水、中高浓度有机废水（如餐厅污水、食品工业废水）等的处理.     

二硫代氨基甲酸盐絮凝处理模拟油田聚合物驱采油废水的效果研究

在碱性条件下,端氨基聚醚Jeffamine-T403与二硫化碳反应合成了二硫代氨基甲酸盐型絮凝剂DTC(T403).考察了DTC(T403)对模拟聚合物驱采油废水的絮凝除油性能,研究了DTC(T403)、水解聚丙烯酰胺(HPAM)、Fe2+和Fe3+的投加量以及pH值对除油效果的影响.结果发现,DTC(T403)与Fe2+络合形成的网状螯合物通过网捕作用取得良好的絮凝除油效果;HPAM的存在影响絮凝除油效果;在同时投加Fe2+和DTC(T403)且二者的投加量分别为10mg/L和25mg/L的条件下,HPAM含量在0～900mg/L范围和含油量约300mg/L的模拟水样经絮凝处理后其含油量均可降到10mg/L以下.DTC(T403)的絮凝除油效果受pH値的影响,在pH7.5条件下可取得良好的除油效果.DTC(T403)适用于含Fe2+的聚合物驱采油废水的处理.     

高浓度苯磺酸甲酯废水处理方法的研究

对苯磺酸甲酯生产工艺排出的主要两股高浓度废水进行了治理方法的探索试验?结果表明,磺化洗水经石灰乳中和及一次减压蒸发,其COD_Cr值从1.48×104mg/L降至161mg/L,去除率为98.9%;酯化洗水经液碱中和?减压蒸发?分馏和精馏甲醇,其COD_Cr值从1.09×105mg/L降至1529mg/L,去除率为98.6%?生产规模为年产苯磺酸甲酯400t,从其排出的废水中每年可以回收工业甲醇83.2t和苯磺酸钠139t,减少COD_Cr的排放量308.7t?      

小球藻高效净化猪场废水厌氧发酵沼液研究

为了净化脱除养猪场废水厌氧发酵沼液中的主要污染物,本文利用臭氧氧化对沼液灭菌并且降解其中的大分子有机物(效果优于高压蒸汽灭菌法),然后高效培养小球藻转化为生物质变废为宝.研究了通入不同体积浓度CO_2以及在沼液中补充部分营养盐对微藻生长净化沼液的影响.当CO_2体积浓度从2%逐渐增加到30%时,微藻生物质产量和脱除污染物效率先升后降,并在体积浓度为15%时达到峰值.当沼液中补充添加营养盐10 mg·L~(-1)磷和1 mg·L~(-1)铁时,微藻生物质产量相对未添加条件进一步提高了29.1%,达到了5.81 g·L~(-1),相应的COD、TN、NH_3-N、TP和抗生素替米考星等污染物脱除效率分别提高到88.5%、91.2%、93.6%、98.9%和90.7%.因此,小球藻可高效净化猪场厌氧发酵沼液同时生产高值生物质,具有良好的应用前景.     

Fe2+-H2O2法处理DSD酸生产氧化母液的研究

为改善DSD酸氧化母液的可生化降解性,将废液先用有机絮凝剂TS-1(一种季胺盐)处理,TS-1的投加量为3g/L,其后用Fe²⁺-H₂O₂法氧化,Fe²⁺和H₂O₂的量分别为150mg/L,7g/L,废液COD和色度的去除率分别可达64%和62%。经处理后的废水,其BOD₅/COD≈0.3,可以认为已达到生化处理的要求。当H₂O₂的投量为2g/L,经Fe²⁺-H₂O₂氧化处理后的废液,再用FeCl₃进行两级混凝处理(FeCl₃的投加量分别为5g/L和2g/L),则COD和色度的去除率可达90%和95%。     

亚硝酸盐积累对A~2O工艺生物除磷的影响

常温条件下,通过控制好氧区DO浓度为0.3～0.5 mg/L,同时增大系统内回流比以降低系统好氧实际水力停留时间(actual hydraulic retention time,AHRT),在处理低C/N比实际生活污水的A2O工艺中成功启动并维持了短程硝化反硝化.但随着系统出水亚硝酸盐含量的升高,系统对磷的去除效果逐渐恶化.当好氧区亚硝酸盐浓度19 mg/L时,系统出水磷浓度大于进水磷浓度,系统处于净释磷状态.通过对原水COD浓度、反应区温度、pH值、游离亚硝酸浓度(free nitrous acid,FNA)等分析,表明碳源不足及短程硝化引起的亚硝酸盐积累影响了聚磷菌厌氧释磷和好氧吸磷;尤其是好氧区较高的FNA浓度(HNO2-N 0.002～0.003 mg/L)对聚磷菌好氧吸磷的抑制是导致系统除磷效果恶化的直接原因.通过外投碳源提高原水COD浓度,提高了聚磷菌厌氧释磷合成PHA的能力;同时增强了系统的反硝化能力,降低好氧区亚硝酸盐浓度,从而降低FNA对聚磷菌好氧吸磷的抑制程度,系统的除磷性能可迅速恢复;系统对磷的去除率可达96%以上.     

Simultaneous removal of Cu(II) and Cr(VI) by Mg–Al–Cl layered double hydroxide and mechanism insight

Mg–Al–Cl layered double hydroxide (Cl-LDH) was prepared to simultaneously remove Cu(II) and Cr(VI) from aqueous solution. The coexisting Cu(II) (20 mg/L) and Cr(VI) (40 mg/L) were completely removed within 30 min by Cl-LDH in a dosage of 2.0 g/L; the removal rate of Cu(II) was accelerated in the presence of Cr(VI). Moreover, compared with the adsorption of single Cu(II) or Cr(VI), the adsorption capacities of Cl-LDH for Cu(II) and Cr(VI) can be improved by 81.05% and 49.56%, respectively, in the case of coexisting Cu(II) (200 mg/L) and Cr(VI) (400 mg/L). The affecting factors (such as solution initial pH, adsorbent dosage, and contact time) have been systematically investigated. Besides, the changes of pH values and the concentrations of Mg²⁺ and Al³⁺ in relevant solutions were monitored. To get the underlying mechanism, the Cl-LDH samples before and after adsorption were thoroughly characterized by X-ray powder diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. On the basis of these analyses, a possible mechanism was proposed. The coadsorption process involves anion exchange of Cr(VI) with Cl⁻ in Cl-LDH interlayer, isomorphic substitution of Mg²⁺ with Cu²⁺, formation of Cu₂Cl(OH)₃ precipitation, and the adsorption of Cr(VI) by Cu₂Cl(OH)₃. This work provides a new insight into simultaneous removal of heavy metal cations and anions from wastewater by Cl-LDH.     

Fenton氧化/混凝协同处理焦化废水生物出水的研究

对Fenton氧化/混凝协同处理焦化废水生物出水的方法进行了研究,在综合考虑经济性和去除效果的前提下,提出了反应的最佳条件:H₂O₂投加量为220 mg/L,Fe²⁺投加量为180 mg/L,聚丙烯酰胺投加量为4.5 mg/L,反应时间为0.5h,pH=7.最终COD去除率可达44.5%,色度可以降为35倍,出水符合国家污水排放二级标准.同时,通过分析分子量分布和小分子有机物组成,揭示了Fenton氧化/混凝协同处理焦化废水生物出水的污染物变化规律.结果表明焦化废水经过Fenton氧化/混凝协同处理后,其出水可达到国家二级排放标准,并且处理成本相对较低,具有实际应用的前景.