超滤处理木薯淀粉酒精废液及净化液回用研究

研究用超滤膜处理预处理过的木薯淀粉酒精废液,以脱色率及COD去除率作为鉴定指标;并测定处理后净化液的回用效果.试验表明,废液先经过0.3 MC筛网和4000 r/min离心20 min的预处理,再经截流分子量为1万的超滤膜处理后,脱色率为27.7%,COD去除率为34.7%,且膜清洗容易.膜透过液回用效果明显好于未经膜处理的废液,10万膜和1万膜透过液的回用率均可达到80%.     

催化氧化糖蜜酒精废液催化剂的再生研究

以糖蜜酒精废液为原料,考察了载铜活性炭催化剂的再生,并通过正交试验建立了催化剂再生的最佳工艺条件:洗脱液浸渍时间8 h,活化温度300℃,活化时间4 h,超声时间6 h。最佳条件下再生的催化剂用催化氧化法处理糖蜜酒精废液8 h后,COD去除率达76.81%,脱色率达71.44%。     

糖蜜酒精废液的脱色实验研究

以糖蜜酒精废液为研究对象,探讨糖蜜酒精废液的脱色处理.实验先用聚合氯化铝(PAC)和聚丙烯酰胺(PAM)以5∶1复配对糖蜜酒精进行絮凝预处理,可使浊度下降95%,COD去除90%,色度也有一定的下降.然后以活性炭、强氯精及活性炭-强氯精复配对废液进行脱色研究,结果表明单独采用活性炭吸附,脱色效果最好,且在投加量为34 g/L,pH值为4,反应时间为180min,脱色率达95%.     

内电解—催化氧化法处理糖蜜酒精废液的研究

采用内电解—催化氧化法处理糖蜜酒精废液具有较高的COD去除效果。研究了内电解—催化氧化法处理糖蜜酒精废液的效果受反应时间、废液浓度、pH值、反应温度等单因素的影响并进行了正交试验。实验结果表明,反应10h,废液稀释7.5倍,pH=5.50,反应温度60℃,用Cu—AC催化剂,内电解—催化氧化法处理糖蜜酒精废液,其COD去除率可达80.0%。     

内电解-催化氧化法处理糖蜜酒精废液的研究

采用内电解-催化氧化法处理糖蜜酒精废液具有较高的COD去除效果。研究了内电解-催化氧化法处理糖蜜酒精废液的效果受反应时间、废液浓度、pH值、反应温度等单因素的影响并进行了正交试验。实验结果表明,反应10h,废液稀释7.5倍,pH=5.50,反应温度60℃,用Cu-AC催化剂,内电解-催化氧化法处理糖蜜酒精废液,其COD去除率可达80.0%。     

绿色木霉发酵强化糖蜜酒精废液活性炭脱色效果的研究

采用绿色木霉菌株对糖蜜酒精废液进行生物处理,并对处理后的废液进行活性炭脱色试验.考察不同活性炭吸附处理条件和不同绿色木霉培养条件对糖蜜酒精废液生物法脱色的影响,并进行了正交实验.结果表明,在绿色木霉接种量为1%(v/v),培养时间为36h,培养温度为26℃,活性炭投加量为5%的条件下糖蜜酒精废液脱色效果最好,透光率达91.57%.     

光催化处理糖蜜酒精废水的研究

设计流化床光催化氧化工艺处理糖蜜酒精废水的单因素试验,考察催化剂的用量、光强对糖蜜酒精废水光催化降解效果的影响。试验结果表明在所设计的试验条件下,催化剂用量从2g/L增加到5g/L,废水脱色率及COD的去除率将逐渐增大,但继续增大催化剂用量,脱色率、COD去除率反而出现下降的趋势。随着光照强度的增加,废水降解效果越好。     

用壳聚糖二次处理糖蜜酒精废液

以脱色率为指标,研究了壳聚糖处理糖蜜酒精废液的最佳条件,并将这些条件用于培养过云芝菌的糖蜜酒精废液的二次处理。发现,在25℃,pH4.0,搅拌时间30min,壳聚糖用量0.01g/mg,转速400r/min和助凝剂聚丙稀酰胺用量7×10 5g/mL的条件下,脱色效果较好;两次处理后,每升5倍稀酒精废液可产0.65g云芝多糖外,其脱色率、CODcr除去率和pH值分别为9.5%,80.3%和6.3。     

US/Fenton试剂联用降解糖蜜酒精废水

以超声波为辅助条件,采用Fenton试剂进行催化降解糖蜜酒精废水。以废水的COD去除率、废水脱色率为评价指标,考察了US/Fenton试剂对糖蜜酒精废水催化降解特性。实验结果表明Fenton试剂对糖蜜酒精废水具有良好的催化降解效果,超声波与Fenton试剂之间存在着协同作用。     

臭氧对糖蜜酒精废液脱色机理及工艺优化

利用臭氧氧化法处理糖蜜酒精废液,碱性条件下其反应机理属于自由基型反应。通过正交实验确定影响因素的主次为:氧化时间→臭氧流量→反应温度→废液pH值;最佳工艺条件组合为:时间90min、流量0.10m3/h、温度60℃、pH9.0,脱色率为56.92%。     

Desalination of mixed tannery effluent with membrane bioreactor and reverse osmosis treatment

A limiting factor for the reuse and recycling of treated tannery wastewater for irrigation and other uses is the high salt content, which persists even after conventional treatment. Reverse osmosis (RO) membrane treatment has been shown to significantly reduce the salt contents of tannery effluents. However, the high organic content of tannery effluent leads to rapid scaling and biofouling of RO membranes with a consequent reduction in flux rates and performance. Membrane bioreactors (MBR) have been shown to be highly effective in the removal of organic pollutants and suspended solids from tannery effluent. This research investigated the use of a combined MBR and RO treatment process to treat tannery effluents to an acceptable level for irrigation purposes. The MBR was operated at 17-20 h retention time, at a F/M ratio of 0.52 kg COD x kg SS(-1) x day(-1) and a volumetric loading rate of 3.28 kg COD x m(-3) x day(-1). This treatment reduced the COD, BOD, and ammonia concentrations of the effluent by 90-100%. The MBR was shown to be an excellent pretreatment prior to RO technology, due to the high removal efficiency of organic compounds and suspended solids, with average concentrations of 344 mg x L(-1) COD and 20 mg x L(-1) BOD achieved in the permeate. RO treatment reduced the salt content of the MBR permeate by up to 97.1%. The results of the research demonstrated that the MBR system developed was appropriate for the treatment of tannery effluents and, in combination with the RO treatment, reduced the salt content to acceptable levels for irrigation. The MBR pretreatment reduced bio-fouling and scaling of subsequent RO treatment and improved the overall performance of the RO unit. It is believed that this is the first investigation of a combined MBR and RO treatment for tannery effluents. This research provided data for an outline design of a full-scale MBR and RO plant with a treatment capacity of 5000 m3 per day for mixed tannery effluents.     

电-Fenton法预处理CTMP废水

采用电生成Fenton法预处理CTMP废水．主要考察了pH、电流密度、反应时问和温度对废水色度和CODCr去除率的影响，并初步探讨了电芬顿试剂的作用机理。通过实验得到最佳反应条件：极板间距10cm、曝气、pH=5、电流密度80A／m^2和反应时间60min，最佳条件下脱色率达90％以上，CODCr去除率50％以上。     

Decolorization of vegetable oils by membrane processing

Membrane decolorization studies of chlorophyll added sunflower oil and crude soybean oil were conducted in a batch membrane cell using two polymeric composite membranes (NTGS-2100 and NTGS-1100), and one polyethylene microfiltration membrane (PE-30). NTGS-2100 membrane could remove up to 96% and 72% chlorophyll from the undiluted and oil-hexane (50 wt%) solutions, respectively. Permeate oil flux was very low when undiluted oil was used as feed, but improved many fold by diluting with hexane. NTGS-1100 membrane gave higher permeate flux compared to NTGS-2100, but showed reduced rejection. Absorbance spectra of crude soybean oil and the permeate in the 350-550 nm range showed a greater degree of decolorization by polymeric composite membranes. PE-30 membrane showed insignificant rejection of color compounds. The permeate of conventionally bleached soybean oil showed a reduction in extinction coefficients at 232 and 270 nm, indicating possible rejection of dienes and trienes by the composite polymeric membranes. The membrane process was effective in reducing the color compounds in crude vegetable oils besides offering many advantages over the conventional process.     

Effectiveness of Cross-Flow Microfiltration for Removal of Microorganisms Associated with Unpasteurized Liquid Egg White from Process Plant

ABSTRACT:  Thermal preservation is used by the egg industry to ensure the microbiological safety of liquid egg white (LEW); however, it does not eliminate all microorganisms and impairs some of the delicate functional properties of LEW. In this study, a pilot-scale cross-flow microfiltration (MF) process was designed to remove the natural microflora present in commercial LEW, obtained from a local egg-breaking plant, while maintaining the nutritional and functional properties of the LEW. LEW, containing approximately 10^{6 ± 1.7} colony forming units (CFU) per milliliter of total aerobic bacteria, was microfiltered using a ceramic membrane with a nominal pore size of 1.4 μm, at a cross-flow velocity of 6 m/s. To facilitate MF, LEW was screened, homogenized, and then diluted (1 : 2, w/w) with distilled water containing 0.5% sodium chloride. Homogenized LEW was found to have a threefold lower viscosity than unhomogenized LEW. Influence of MF temperature (25 and 40 °C) and pH (6 and 9) on permeate flux, transmission of egg white nutrients across the membrane, and microbial removal efficiency were evaluated. The pH had a significantly greater influence on permeate flux than temperature. Permeate flux increased by almost 148% when pH of LEW was adjusted from pH 9 to pH 6 at 40 °C. Influence of temperature on permeate flux, at a constant pH, however, was found to be inconclusive. Microbial removal efficiency was at least 5 log₁₀ CFU/mL. Total protein and SDS-PAGE analysis indicated that this MF process did not alter the protein composition of the permeate, compared to that of the feed LEW, and that the foaming properties of LEW were retained in the postfiltered samples.     

Fabrication and characterization of silica/titania nanotubes composite membrane with photocatalytic capability

Silica/titania nanotubes composite membranes were successfully prepared from silica/titania sols using porous alumina support membranes. XRD patterns of the composite membranes confirmed that the embedding of amorphous silica into nanophase titania matrix helped to increase the thermal stability of titania which suppressed the phase transformation from anatase to rutile and decreased the size of titania particles. Ninety-five percent of the pore volume of composite membrane was located in mesopores with diameters ranging from 1.4 to 10 nm. The surface of these composite membranes exhibited extremely high affinity for water under UV irradiation with water contact angle decreased from 62 degrees to nearly 5 degrees within 80 min. By coupling membrane separation with photocatalysis technique, the removal efficiency of Direct Black 168 was improved remarkably; being 85% within 100 min, while the values were 66% and 73% with photocatalysis alone or membrane separation alone during the same time, respectively. Good photocatalytic activity and wettability of composite membrane under UV irradiation helped to obtain high permeate flux across the composite membrane. The silica/titania nanotubes composite membrane had the multifunctions of separation, degradation, and improvement of membrane flux in photooxidation of organic contaminants in wastewater.     

聚醚砜超滤膜分离菜籽油/乙醇混合物的研究

用聚醚砜超滤膜分离菜籽油/乙醇混合物,研究了混合物中菜籽油质量分数(20%～60%)、操作压力(0.15～0.3 MPa)和时间(10～60 min)等参数对分离效果的影响,并探讨了该膜渗透通量的数学模型.结果表明:膜的渗透通量随着操作压力的升高而升高,随时间的延长和混合物中菜籽油质量分数的提高而降低;膜对油脂的截留率随着操作压力的升高、混合物中菜籽油质量分数的提高而降低.当操作压力为0.15 MPa、菜籽油/乙醇混合物质量分数为20%时,得到最高的油脂截留率为95.03%.     

Anaerobic fluidized bed membrane bioreactor for wastewater treatment

Anaerobic membrane bioreactors have potential for energy-efficient treatment of domestic and other wastewaters, membrane fouling being a major hurdle to application. It was found that fouling can be controlled if membranes are placed directly in contact with the granular activated carbon (GAC) in an anaerobic fluidized bed bioreactor (AFMBR) used here for post-treatment of effluent from another anaerobic reactor treating dilute wastewater. A 120-d continuous-feed evaluation was conducted using this two-stage anaerobic treatment system operated at 35 °C and fed a synthetic wastewater with chemical oxygen demand (COD) averaging 513 mg/L. The first-stage was a similar fluidized-bed bioreactor without membranes (AFBR), operated at 2.0-2.8 h hydraulic retention time (HRT), and was followed by the above AFMBR, operating at 2.2 h HRT. Successful membrane cleaning was practiced twice. After the second cleaning and membrane flux set at 10 L/m(2)/h, transmembrane pressure increased linearly from 0.075 to only 0.1 bar during the final 40 d of operation. COD removals were 88% and 87% in the respective reactors and 99% overall, with permeate COD of 7 ± 4 mg/L. Total energy required for fluidization for both reactors combined was 0.058 kWh/m(3), which could be satisfied by using only 30% of the gaseous methane energy produced. That of the AFMBR alone was 0.028 kWh/m(3), which is significantly less than reported for other submerged membrane bioreactors with gas sparging for fouling control.     

Efficiency of serum protein removal from skim milk with ceramic and polymeric membranes at 50°C

Raw milk (2,710 kg) was separated at 4°C, the skim milk was pasteurized (72°C, 16 s), split into 3 batches, and microfiltered using pilot-scale ceramic uniform transmembrane pressure (UTP; Membralox model EP1940GL0.1μA, 0.1 μm alumina, Pall Corp., East Hills, NY), ceramic graded permeability (GP; Membralox model EP1940GL0.1μAGP1020, 0.1 μm alumina, Pall Corp.), and polymeric spiral-wound (SW; model FG7838-OS0x-S, 0.3 μm polyvinylidene fluoride, Parker-Hannifin, Process Advanced Filtration Division, Tell City, IN) membranes. There were differences in flux among ceramic UTP, ceramic GP, and polymeric SW microfiltration membranes (54.08, 71.79, and 16.21 kg/m² per hour, respectively) when processing skim milk at 50°C in a continuous bleed-and-feed 3× process. These differences in flux among the membranes would influence the amount of membrane surface area required to process a given volume of milk in a given time. Further work is needed to determine if these differences in flux are maintained over longer processing times. The true protein contents of the microfiltration permeates from UTP and GP membranes were higher than from SW membranes (0.57, 0.56, and 0.38%, respectively). Sodium-dodecyl-sulfate-PAGE gels for permeates revealed a higher casein proportion in GP and SW permeate than in UTP permeate, with the highest passage of casein through the GP membrane under the operational conditions used in this study. The slight cloudiness of the permeates produced using the GP and SW systems may have been due to the presence of a small amount of casein, which may present an obstacle in their use in applications when clarity is an important functional characteristic. More β-lactoglobulin passed through the ceramic membranes than through the polymeric membrane. The efficiency of removal of serum proteins in a continuous bleed-and-feed 3× process at 50°C was 64.40% for UTP, 61.04% for GP, and 38.62% for SW microfiltration membranes. The SW polymeric membranes had a much higher rejection of serum proteins than did the ceramic membranes, consistent with the sodium-dodecyl-sulfate PAGE data. Multiple stages and diafiltration would be required to produce a 60 to 65% serum protein reduced micellar casein concentrate with SW membranes, whereas only one stage would be needed for the ceramic membranes used in this study.     

Separation of non-sucrose compounds from syrup as a part of the sugar-beet production process by ultrafiltration with ceramic membranes

Non-sucrose compounds having intensive colour tend to build into the sucrose crystals during the crystallization. Their removal, or decrease of their concentration in sugar syrup, is a very important operation. The subject of this laboratory investigation was a separation process performed by ceramic tubular membrane in two modes of operation: with static mixer (SM) and without static mixer (NSM). In order to compare two alternatives as well as to determine optimal operating conditions, in both modes, solution flow rate, temperature, transmembrane pressure and process duration were varied independently and their influence on the permeate flux as well as on the efficiency of decolourization and purification were examined. The cross-flow filtration was carried out on ceramic tubular membrane with pore diameter of 20 nm. The obtained results have shown that permeate flux increased approximately 30%, at 80 °C, and 65%, at 70 °C, when static mixer was used. Significant part of coloured compounds—45% in average, determined by the absorbance measurement of permeate/feed, was separated from the raw sugar syrup. Decolourization in SM-mode is greater than the decolourization in NSM-mode (30% after 0.5 h and 55% after 2 h). Purity was eliminated with an efficiency of 80% in average compared to the feed, with the similar success when NSM-mode and SM-mode of operation were applied, particularly at the end of ultrafiltration.     

高取代度阳离子淀粉在印染废水处理中的应用

 采用半干法合成出高取代度(DS=0.4)的阳离子淀粉,其反应效率88.89%。应用实验结果表明,在室温下,当高取代度阳离子淀粉的加入量在200～300 mg/L,印染废水的pH值为11时,该阳离子淀粉对实际印染废水的脱色率能够达到78%,COD去除率能达到90%。