活性炭纤维布吸附与电热脱附挥发性有机化合物研究进展(英文)

A general research program,focusing on activated carbon fiber cloths(ACFC) and felt for environmental protection was performed.The objectives were multiple:(i) a better understanding of the adsorption mechanisms of these kinds of materials;(ii) the specification and optimization of new processes using these adsorbents;(iii) the modeling of the adsorption of organic pollutants using both the usual and original approaches;(iv) applications of ACFC in industrial processes.The general question was:how can activated carbon fiber cloths and felts be used in air treatment processes for the protection of environment.In order to provide an answer,different approaches were adopted.The materials(ACFC) were characterized in terms of macro structure and internal porosity.Specific studies were performed to get the air flow pattern through the fabrics.Head loss data were generated and modeled as a function of air velocity.The performances of ACF to remove volatile organic compounds(VOCs) were approached with the adsorption isotherms and breakthrough curves in various operating conditions.Regeneration by Joule effect shows a homogenous heating of adsorber modules with rolled or pleated layers.Examples of industrial developments were presented showing an interesting technology for the removal of VOCs,such as dichloromethane,benzene,isopropyl alcohol and toluene,alone or in a complex mixture.     

剩余活性污泥碱性发酵液用于厌氧交替好氧-缺氧序批式反应器生物除磷脱氮的碳源的研究(英文)

Activated sludge process has been widely used to remove phosphorus and nitrogen from wastewater. However, the nitrogen and phosphorus removal is sometimes unsatisfactory due to the low influent COD. Another problem with the activated sludge process is that large amount of waste activated sludge is produced, which needs further treatment. In this study, the waste activated sludge alkaline fermentation liquid was used as the main carbon source for phosphorus and nitrogen removal under anaerobic followed by alternating aerobic-anoxic conditions, and the results were compared with those using acetic acid as the carbon source. The use of alkaline fermentation liquid not only affected the transformations of phosphorus, nitrogen, intracellular polyhydroxyalkanoates and glycogen, but also led to higher removal efficiencies for phosphorus and nitrogen compared with acetic acid. It was observed that ammonium was completely removed with either alkaline fermentation liquid or acetic acid as the carbon source. However, the former resulted in higher removal efficiencies for phosphorus (95%) and nitrogen (82%), while the latter showed lower ones (87% and 74%, respectively). The presence of a large amount of propionic acid in the alkaline fermentation liquid was one possible reason for its higher phosphorus removal efficiency. Exogenous instead of endogenous denitrification was the main pathway for nitrogen removal with the alkaline fermentation liquid as the carbon source, which was responsible for its higher nitrogen removal efficiency. It seems that the alkaline fermentation liquid can replace acetic acid as the carbon source for phosphorus and nitrogen removal in anaerobic followed by alternating aerobic-anoxic sequencing batch reactor.     

硝酸浓度对橄榄石基活性炭特性的影响(英文)

In this work we investigated the effect of nitric acid concentration on the pore structure, surface chemistry and liquid phase adsorption of olive stone based activated carbon prepared by mixing process using phosphoric acid and steam as activating agents. Chemicals and textural characterization show that the increase of HNO3 concentration increases considerably the total acidic groups but decreases specific surface area and pore volume. The study of adsorption in aqueous solutions of two organics, phenol and methylene blue, on raw and oxidized activated carbon indicates that the treatment of mixed activated carbon with different concentrations of nitric acid improves the adsorbent capacity for methylene blue at HNO3 concentrations less or equal to 2 mol·L 1, while it has a negative effect on phenol adsorption.     

回流污泥预浓缩强化新型氧化沟系统生物除磷的研究(英文)

A pilot-scale,pre-anoxic-anaerobic oxidation ditch was used in this study to treat municipal wastewater with limited carbon source.A novel return activated sludge(RAS) pre-concentration tank was adopted for improv-ing the phosphorus removal efficiency and the effects of RAS pre-concentration ratio were studied.Under the opti-mal operational condition,the suspended total phosphorus(STP) and the total phosphorus(TP) removal efficiencies were around 58.9% and 63.9% respectively and the effluent-P was lower than 0.8 mg·L-1.The reason is that with the optimal RAS pre-concentration ratio,nitrate is completely removed with endogenous carbon source and the secondary phosphorus release is strictly restrained in the pre-anoxic tank.Therefore,the anaerobic phosphorus release and the carbon source uptake by phosphorus accumulation organisms(PAOs) in the sludge,which are ex-tremely important to the phosphorus removal process,can be fully satisfied.Furthermore,the oxidation-reduction potential is proved to be suitable for controlling the RAS pre-concentration ratio due to influent fluctuation and varied conditions.The novel modified system is also beneficial for PAO accumulation.     

九种钠盐对污泥电渗透脱水的影响

对9种常见钠盐(NaCl、NaNO_3、Na_2CO_3、NaHCO_3、Na_2SO_4、Na_3PO_4、Na_2HPO_4、NaH_2PO_4、CH_3COONa)进行电渗透脱水实验研究,结果表明:机械压力为15 kPa,电压为16 V/cm,污泥厚度为0.5 cm,在使得污泥含水率降至60%的前提下,添加1 g/kg WS(湿污泥重量)的Na_2HPO_4所需的电渗透脱水时间和脱水能耗为最低。     

微生物-化学耦合法再生活性炭的研究(英文)

In this study,spent activated carbon(AC) saturated with caramel was regenerated by using yeast and NaOH.The efficiency of regeneration was evaluated under parameters such as amount,treatment time,temperature,pH value,stirring temperature of yeast and NaOH concentration.The optimum condition for AC regeneration was 8 h for yeast treatment time,35 ℃ for 0.075% yeast culture temperature,a pH value of 6 for the yeast dealing with the spent AC,90 ℃ for NaOH stirring temperature of AC and 6% NaOH for washing after the spent AC was treated by yeast.Under these conditions,methylene blue(MB) adsorption was 213 mg·g-1 in comparison with 60 mg·g-1 of spent AC.The micro structure and surface area of the regenerated AC were characterized by scanning electron mi-croscope(SEM) and N2 sorption,respectively.The pore size distributions of virgin and regenerated AC were ana-lyzed by means of H-K equation,resulting in a mean pore diameter of 1.28 nm and a pore volume of 1.13 cm3·g-1.This study provides data for theoretical support of the AC regeneration technology.     

O3-BAC工艺炭滤池出水pH变化关键因素及其调节措施的研究（英文）

An investigation was carried out to eliminate the decrease of effluent pH value in carbon filter in O3-biological activated carbon process. The influence factors were examined in a pilot test, and pH was adjusted in the pilot and waterworks. Results show that the carbon filter is an acid-base buffer system and the activated carbon is the key factor. Chemical functional groups on activated carbon surface present acid-base properties to buffer the water but decrease with time, so that effluent pH value decreases. The effects of ozone dosage, CO2 in the carbon filter, and the filter influent quality are negligible. A new method to adjust pH is developed: the activated carbon is first modified by soaking in sodium hydroxide solution to make its pH reach the desired value, and then the pH value of inflow is controlled to certain value by dosing lime in sand filter influent. The method is economical and effective.     

磁化调质对活性污泥脱水性能的影响

研究了磁场调质对污水厂活性污泥脱水性能的影响,在不同磁场强度和磁化时间下,考察了活性污泥沉降性能、污泥比阻、分形维数、污泥粒径等参数的变化规律。结果表明:磁化时间为20 min、磁场强度为55 m T时,污泥的沉降性能最佳,污泥结构最为密实,污泥比阻可由原来的2.03×1013 m/kg下降到9.5×1012 m/kg,能有效改善污泥的脱水性能。     

废轮胎二氧化碳活化借助析因设计的系统分析(英文)

In this study,waste tire was used as raw material for the production of activated carbons through pyrolysis.Tire char was first produced by carbonization at 550℃ under nitrogen.A two factorial design was used to optimize the production of activated carbon from tire char.The effects of several factors controlling the activation process,such as temperature(850-950 ℃),time(2-6 h) and percentage of carbon dioxide(70%-100%) were investigated.The production was described mathematically as a function of these three factors.First order modeling equations were developed for surface area,yield and mesopore volume.It was concluded that the yield,BET surface area and mesopore volume of activated carbon were most sensitive to activation temperature and time while percentage of carbon dioxide in the activation gas was a less significant factor.     

正磷酸活化木质素吸附Cr(Ⅵ)的固定床实验和模型(英文)

The advantage of using an available and abundant residual biomass,such as lignin,as a raw material for activated carbons is that it provides additional economical interest to the technical studies.In the current investigation,a more complete understanding of adsorption of Cr(VI) from aqueous systems onto H3PO4-acid activated lignin has been achieved via microcolumns,which were operated under various process conditions.The practice of using microcolumn is appropriate for defining the adsorption parameters and for screening a large number of potential adsorbents.The effects of solution pH(2-8),initial metal ion concentration(0.483-1.981 mmol·L-1),flow rate(1.0-3.1 cm3·min-1),ionic strength(0.01-0.30 mmol·L-1) and adsorbent mass(0.11-0.465 g) on Cr(VI) adsorption were studied by assessing the microcolumn breakthrough curve.The microcolumn data were fitted by the Thomas model,the modified Dose model and the BDST model.As expected,the adsorption capacity increased with initial Cr(VI) concentration.High linear flow rates,pH values and ionic strength led to early breakthrough of Cr(VI).The model constants obtained in this study can be used for the design of pilot scale adsorption process.     

生物滤池-活性污泥法处理啤酒废水的实践

衡阳啤酒厂废水处理站设计规模为2100m^3/d;进水CODCr=800-1500mg/L,BOD5=400-800mg/L,SS=300-600mg/L。采用高负荷生物滤池－活性污泥法处理工艺,运行表明出水水质达到GB8978－1988污水综合排放标准中规定的一级标准,且投资省。     

壳聚糖絮凝剂的投加量对污泥脱水性能的影响

通过污泥比阻的测定,分析絮凝剂剂量对污泥脱水性能的影响。同时对三氯化铝、阳离子聚丙烯酰胺、壳聚糖以及复合絮凝剂的絮凝效果进行比较。结果表明,无论是无机絮凝剂和有机絮凝剂都存在最佳剂量,小于或大于最佳投加量,絮凝效果都不好。阳离子聚丙烯酰胺(CPAM)、壳聚糖、三氯化铝的最佳投加质量浓度分别为0．2g/L、10g/L、35g/L。与三氯化铝相比,阳离子聚丙烯酰胺的药剂消耗量要低得多。壳聚糖与CPAM相比,在达到相同的絮凝效果时,壳聚糖的用量大于CPAM的用量。将壳聚糖与氯化铝复合,用两段法应用于污泥调理,研究这种复合絮凝剂的脱水性能,实验表明壳聚糖和三氯化铝复合,能大大提高污泥的脱水性能。     

Municipal sludge dewatering by belt filter press: effect of operating parameters

A belt filter press is commonly used to dewater sewage sludge but few data concerning this process have been published. A laboratory‐scale investigation was carried out to highlight the main process parameters affecting belt filter press efficiency as measured by the dry solid content of the final cake, percentage of solids recovered, and lateral sludge migration on the belt. Belt speed was determined to be the most important parameter: a low belt speed produces drier cakes with lower lateral sludge migration on the belt and also improves filtrate quality. At low belt speed, pressure is gently applied to the initial sludge, enabling a slow structuring of the cake and leading to better water release. Copyright © 2005 Society of Chemical Industry     

城市污水污泥脱水的最新研究进展

随着"十一五"污水处理厂建设数量的大幅增加,我国污泥产量也随之急剧增长,污泥的处理处置已成为制约社会经济发展的重要问题。综述了近十年国内外有关污水污泥脱水的最新研究进展,提出了存在的问题,并对未来研究方向进行了展望。     

超声辅助污泥脱水的研究

为了研究超声对污泥脱水性能的影响,在污泥板框压滤实验中,利用超声结合絮凝剂聚丙烯酰胺(PAM)处理污泥的方法,对比了有无超声对污泥压滤脱水的效果。研究结果表明:超声可以降低污泥含水率,使其从最初含水率近98%减少到81%,污泥的体积减少为最初的1/10。超声声强为410 W/m2、超声处理时间2.5 m in为较优处理条件;同时絮凝剂的使用量,从0.7%(干基)降至0.6%(干基)。     

带式压滤机化学污泥脱水在生产中的应用

为配合中国石油吉林石化公司30万t／a乙烯工程A／O工艺废水处理工程化学污泥脱水的需要,进行了DY(12000-XB型带式压滤机应用于化学污泥脱水生产性能力考核测试。确定了最佳带速、带张紧压力、投泥量、投药量和产泥量等指标,具有显著的经济和环境效益。在相同产泥量务件下．该带式压滤机比WL(F)-600Ⅱ型离心机年运行费用可节约58．86万元。     

污泥深度脱水技术研究进展

随着经济的发展和国民生活水平的提高,污水污泥的排放量逐年增加,环境问题愈发严重,污泥的处理处置成为焦点问题,污泥脱水是制约污泥处置处理进一步发展的关键。本文针对目前污泥深度脱水技术开展,首先简述了不同来源污泥的分类及其基本特性,然后重点阐述了不同污泥预处理技术,分析了各污泥深度脱水技术作用机理,并对各自脱水效果及优缺点进行比较分析。结果表明,物理法中水热预处理对污泥的可脱水程度提升最大。较低声强、短时间的超声波处理对污泥脱水性能有着明显的改善。化学法在污泥过滤性能以及脱水速率方面有很大优势,酸碱处理后污泥zeta电位上升,污泥过滤性能及脱水速率得到改善。高级氧化法处理后污泥脱水效果高于酸碱处理,微生物细胞被溶解释放出有机物,可脱水程度改善。生物法处理污泥除改善污泥脱水性能外,还有对环境污染小等特点,但耗时较长。最后对污泥的后续脱水工艺进行综述,介绍了现存的主流脱水工艺,包括机械脱水、热干化技术、水热脱水工艺等;并针对不同的污泥后续利用方法,选取合适的预处理技术,提出相应优化的污泥处理工艺流程。     

改性壳聚糖对处理污泥脱水性能影响的研究

研究了聚合氯化铝、壳聚糖和3种羧甲基壳聚糖(N-羧甲基壳聚糖、N,O-羧甲基壳聚糖和O-羧甲基壳聚糖)絮凝剂对污泥的脱水性能作用。实验结果表明,羧甲基壳聚糖作为絮凝剂对污泥进行脱水时,形成的絮体强度大,不易破碎,对污泥脱水的效果明显好于普通絮凝剂。在3种所研究的羧甲基壳聚糖中,N-羧甲基壳聚糖对污泥的脱水效果最好,污泥比阻抗最低,与未加絮凝剂时相比,含水率从99.1%下降到73%,污泥的体积减少为原来的1/30,热值提高为原来的40倍。     

污泥深度脱水调理剂对污泥干化过程中含硫气体释放的影响

采用5种复合调理剂改善污泥脱水性能,制得深度脱水泥饼。通过检测N₂气氛下,不同干化温度（100℃、200℃）,停留时间（30 min、60 min）时,不同调理脱水污泥含水率的变化情况,以及含硫气体的种类和释放量,探讨不同调理剂对干化过程中含硫气体释放特性的影响。结果表明,提高温度、延长时间都可以有效降低污泥的含水率;原污泥干化过程释放的主要含硫气体为H₂S和SO₂,其总量占含硫气体的82.4%;FeCl₃+CaO和H₂SO₄+FeSO₄+H₂O₂+CaO复合调理剂调理脱水泥饼在干化过程中SO₂释放量占原污泥释放量的40.3%和40.6%,H₂S则基本没有释放;H₂SO₄+FeSO₄+H₂O₂+CaO调理脱水污泥在100℃和200℃干化过程中的总硫释放量分别占原污泥总释放量的75.0%和45.6%,该复合调理剂在有效提高污泥脱水性能的基础上,能最大限度地抑制含硫气体的释放。     

优化超声波联合絮凝剂强化污泥脱水的研究

研究了超声波、絮凝剂、超声波联合絮凝剂强化污泥脱水的效果。结果表明,单独采用超声波处理时,双频超声波的污泥脱水效果优于单频超声波;单独絮凝剂处理时,硫酸铝的污泥脱水效果优于硫酸铁和聚丙烯酰胺。超声波联合絮凝剂处理时,投加硫酸铝和超声波处理同时进行的污泥脱水效果最佳,正交回归优化超声时间(X1)、絮凝剂投加量(X2)、超声功率(X3)三者之间的线性关系为Y=0.864+0.13X1+0.09X2+0.01X3+0.03X1X2。