催化氧化-A/O工艺-生物滤池处理高浓度有机胺废水中试

试验采用催化氧化-A/O工艺-生物滤池组合工艺,以高浓度有机胺废水为研究对象,重点考察了该工艺对进水COD、氨氮和总氮的去除效果。结果表明:采用催化氧化预处理工艺,能有效降低废水中的抑制性物质,提高废水的B/C;A/O工艺能去除大量的有机物和总氮,但出水氨氮有所升高;末端采用生物滤池处理该废水,能有效降低废水中的氨氮和COD。当进水ρ(COD)为3 000～4 000 mg/L、ρ(NH3-N)为15～60 mg/L、ρ(TN)为350～450 mg/L时,出水水质可达当地环保要求的排放标准:ρ(COD)≤300 mg/L、ρ(NH3-N)≤35mg/L,表明该工艺可应用于高浓度有机胺废水的处理。     

生物强化/混凝沉淀工艺处理电镀园区物化出水的试验研究

试验采用生物强化/混凝沉淀工艺处理电镀工业园区的物化出水,重点考察了本工艺对进水COD、氨氮的去除效果.结果表明,生物强化工艺能有效降低废水中的COD、氨氮,混凝沉淀工艺能进一步去除废水中的污染物.当进水COD在200～ 350 mg/L、氨氮在20～35 mg/L时,出水水质能够达到《电镀污染物排放标准》(GB 21900-2008)中表2的标准,即COD≤80 mg/L、氨氮≤15 mg/L.     

化学混凝与曝气生物滤池组合工艺用于再生水处理中试研究

将化学混凝与曝气生物滤池(BAF)结合,利用混凝处理和生物膜过滤的双重作用,对城市污水处理厂二级处理出水进行深度处理,以实现污水的回用.结果表明:在原水ρ(COD_Cr),ρ(SS)和ρ(氨氮)分别为78,11和13 mg/L,色度为12倍时,出水ρ(COD_Cr),ρ(SS)和ρ(氨氮)分别为38,3和7mg/L左右,色度为2倍左右.相对于单独使用BAF,组合工艺对COD_Cr的去除率有所提高,色度去除率提高明显(50%左右).膨胀聚丙烯(EPP)填料最佳SS和COD_Cr去除率对应的滤层高度分别为1.0和2.5 m,在较高滤层处,氨氮去除率上升较快.      

生物接触氧化+混凝沉淀工艺处理医院综合污水

利用生物接触氧化、混凝沉淀工艺改造原处理工艺,处理中型医院综合污水,设计能力100 m3/d,处理效果显著且稳定达标。废水进水水质ρ(COD)为408~594 mg/L、ρ(SS)为211~280 mg/L;调试稳定后,出水水质ρ(COD)为12~40 mg/L、ρ(SS)为11~18 mg/L,COD、SS去除率分别为90.2%~97.9%、91.5%~96.1%,出水水质达山东省DB37/596-2006《医疗污染物排放标准》的二级排放标准。     

聚醚废水处理工艺研究

研究了中和混凝-厌氧十好氧-生物活性炭组合工艺,在不同工况和运行参数条件下处理聚醚废水的效果．结果表明,中和混凝能有效地降低生物处理的污泥负荷,调节pH值6．7,聚合氯化铝的投加量为l00mg/L时．聚醚废水COD去除率可达28％,当进水的COD为3000～4000mg/L时,聚醚废水经此组合工艺处理后,COD的总去除率达96％以上,出水COD值约150mg/L.     

BAF-BAC工艺在炼油厂二级出水深度处理中的应用

采用曝气生物滤池-生物活性炭工艺对炼油厂二级处理出水的深度处理进行中试研究,拟探索炼油厂废水深度处理用于循环冷却水补水新工艺.结果表明,当进水COD浓度小于130mg/L,BAF滤速低于4.24m/h条件下运行时,该工艺平均出水COD浓度小于50mg/L,平均出水浊度为4.46NTU,同时对NH₄⁺-N也有一定的去除作用.     

序批式曝气生物滤池处理生活污水的中试研究

报道了沸石为填料的序批式曝气生物滤池处理生活污水的中试实验,研究了曝气时间、曝气量和生活污水浓度对处理效果的影响。结果表明,沸石作曝气生物滤池的填料效果较好。曝气2h后,即可达到很好的去除效果,污水进水COD和BOD5浓度分别为300～800mg/L和170～400mg/L时,去除率分别达到90%～70%和90%～88%。进水COD浓度分别为312.6mg/L和530.6mg/L,曝气量0.6m3/h,处理2h后出水COD浓度分别为30.63mg/L和103.92mg/L,去除率>90%,出水达到污水处理二级排放标准。因此,以沸石为填料的序批式曝气生物滤池是一种高效、低耗、具有较好应用前景的单体生活污水处理设备。     

购物中心综合污水处理工艺改造

分析某购物中心综合污水现有处理工艺的缺陷和潜力,通过调整出水回流,将生物接触氧化工艺一级改造为二级,调节鼓风量,设计能力由300 m3/d提高到400 m3/d,废水进水水质ρ(COD)由500 mg/L提高到1 083～1 146 mg/L,改造调试稳定后,出水水质ρ(COD)为126～140 mg/L,COD去除率为87%～93%,出水水质达GB 8978—1996《污水综合排放标准》二级排放标准。     

厌氧消化与SBR组合工艺处理城市垃圾渗滤液

将ASBR和SBR反应器组合起来,形成一种序批式操作的城市垃圾渗滤液处理工艺。ASBR反应器作为厌氧消化反应器,主要完成初步降解有机物的目的,将原水加入ASBR中进行厌氧消化,研究了废水在28.8~72 h四种不同水力停留时间(HRT)下的处理效果,结果表明,将ASBR的HRT控制在36 h,COD去除率保持41.2%的同时,出水ρ(BOD5)/ρ(COD)及ρ(BOD5)/ρ(NH4+-N)分别为0.41和4.6,对有机物和氮的后续好氧生物去除较为有利。经SBR处理后出水NH4+-N含量稳定在11 mg/L左右,但出水COD浓度达不到排放标准,经添加混凝剂聚合硫酸铁(PFS)混凝沉淀处理后废水中COD含量可降至100 mg/L以下。     

二级曝气生物滤池(BAF)工艺在屠宰废水处理中的应用

屠宰废水有机物浓度和色度较高,水质和水量波动较大。采用连续流二级曝气生物滤池(BAF)处理东北某肉业集团公司屠宰加工废水,在进水COD浓度为3 000~3 200 mg/L,BOD5为1 000~1 200 mg/L,SS=1 000~1 200 mg/L的情况下,对系统的处理性能进行研究。结果表明,当气/水比为2:1时,二级BAF去除污染物效果最好,此时,系统对COD、BOD5、氨氮、TN和SS总的去除率分别为87.11%、87.78%、91.1%、51.0%和92.1%。BAF工艺表现出了较强的处理能力和抗冲击负荷能力,出水能够连续稳定地满足国家《肉类加工工业水污染物排放标准》(GB13457-92)二级排放标准。     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Evaluation of phytoextracting cadmium and lead by sunflower, ricinus, alfalfa and mustard in hydroponic culture

Soil contaminated with heavy metals cadmium(Cd)and lead(Pb)is hard to be remediated.Phytoremediation may be a feasible method to remove toxic metals from soil,but there are few suitable plants which can hyperaccumulate metals.In this study,Cd and Pb accumulation by four plants including sunflower(Helianthus annuus L.),mustard(Brassica juncea L.),alfalfa(Medicago sativa L.), ricinus(Ricinus communis L.)in hydroponic cultures was compared.Results showed that these plants could phytocxtract heavy metals, the ability of accumulation differed with species,concentrations and categories of heavy metals.Values of BCF(bioconcentration factor)and TF(translocation factor)indicated that four species had dissimilar abilities of phytoextraction and transportation of heavy metals.Changes on the biomass of plants,pH and Eh at different treatments revealed that these four plants had distinct responses to Cd and Pb in cultures.Measurements should be taken to improve the phytoremediation of sites contaminated with heavy metals,such as pH and Eh regulations,and so forth.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.