谷壳源胺基修饰的石墨烯纳米纤维对水样中酸性大红GR脱除性能研究

采用典型偶氮染料酸性大红GR为模板污染物,以制得的谷壳源胺基修饰的石墨烯纳米纤维(aGRNF)为吸附脱除材料,深入研究了水样中模板污染物酸性大红GR的脱除效果。分别研究了脱除时间、水样pH、aGRNF添加量及染料起始浓度等不同因素对酸性大红GR染料的脱除效果的影响。研究结果表明,制得的aGRNF与酸性大红GR间极易通过氢键、π-π键等形成弱相互作用,使得吸附脱除效果更为显著,常温下,小剂量aGRNF纳米材料即可有效脱除0.2~4.0mg/mL较宽浓度范围的水样中酸性大红GR污染物,在酸性大红GR初始浓度为1.0mg/mL,aGRNF用量为1.5mg,脱除时间为120min条件下,aGRNF对酸性大红GR的脱除效果最好,脱除率最高达到97.1%,充分展现了该纳米材料在水质净化领域的应用潜力。     

有机改性凹凸棒石吸附活性艳蓝KN-R的动力学研究

通过静态吸附实验方法,研究了有机改性凹凸棒石吸附活性艳蓝KN-R的动力学行为。研究结果表明:准二级动力学模型能很好地描述活性艳蓝KN-R在有机改性凹凸棒石上的动力学行为,平衡吸附量q2随着KN-R初始浓度、振荡速度、温度的增加而增加。有机改性凹凸棒石吸附活性艳蓝KN-R主要是外表面吸附,吸附活化能为39.2kJ/mol,说明其为物理吸附、化学吸附综合作用的过程,其速率由化学过程与外扩散共同控制。     

配位聚合物Cu_3(BTC)_2的制备及对废水中活性大红染料的高效去除

用配位调控法在室温下制备了配位聚合物材料Cu_3(BTC)_2。通过粉末XRD、SEM、N_2吸附、TGA等手段对样品的物相、形貌和比表面积及热稳定性进行了表征。结果表明,制备的配位聚合物材料Cu_3(BTC)_2为球形纳米颗粒,BET比表面积为1 183m~2/g。考察了Cu_3(BTC)_2对活性大红染料废水的处理效果,探讨了吸附剂加入量、pH值、活性大红初始浓度及反应时间对吸附过程的影响。结果表明,吸附剂Cu_3(BTC)_2对活性大红染料具有较高的吸附性能,平衡吸附量可达83.33mg/g。吸附等温线拟合结果较好的符合Langmuir模型,动力学研究结果表明吸附过程符合准二级动力学模型。     

二氧化钛粉体处理印染废水的试验性研究

利用半导体二氧化钛粉体光催化氧化法,对影响分散大红和活性艳兰两种染料的光降解率的因素--染料初始浓度、光照时间、催化剂TiO2用量、溶液初始pH值进行了研究,找出了最佳的反应条件,使处理后的水达到较高的标准.并对羟基和H+离子在光催化氧化法中对染料发色基团作用机理进行了初步分析.     

海藻活性炭及其铁改性Fenton体系去除水中抗生素研究

以大型海藻为原料,采用磷酸活化法制备海藻活性炭(SAC),并以海藻活性炭SAC为吸附剂,抗生素阿莫西林溶液为吸附质,考察了海藻活性炭SAC吸附阿莫西林的初始溶液浓度、pH值的影响。采用准一级、准二级动力学吸附模型对吸附动力学进行了分析。结果表明,海藻活性炭SAC对阿莫西林的吸附符合准二级动力学过程。采用水热法进一步对所制备的海藻活性炭SAC进行铁改性,组成了铁改性海藻活性炭Fenton体系,探讨了以不同比例铁改性海藻活性炭组成的可见光Fenton体系对水中阿莫西林溶液的COD去除率,Fe/SAC-3样品COD去除率为72.5%,具有最佳反应活性。     

葫芦脲[6]接枝壳聚糖的制备及其对偶氮染料的吸附研究

制备葫芦脲[6]接枝壳聚糖(CB[6]-CS)吸附剂,分别获得3种不同接枝率的CB[6]-CS,并对其结构进行表征。将合成的3种吸附剂CB[6]-CS用于对酸性铬兰K染料进行吸附研究,分别考察了温度、pH值、染料浓度、吸附时间及CB[6]含量对吸附性能的影响。结果表明:CB[6]含量较高时,CB[6]-CS对酸性铬兰K有较高的去除率,并且,CB[6]-CS对酸性铬兰K的吸附作用受溶液的温度和pH影响较大,适宜的吸附条件为25℃,pH大于6.5。通过吸附等温线研究,可知,CB[6]-CS对酸性铬兰K的吸附规律更符合Freundlich吸附等温式;吸附动力学采用了准一级速率方程和准二级速率方程来描述,结果表明吸附动力学符合准二级速率方程。     

B、N和Ce共掺杂TiO_2光催化降解染料废水研究

采用B、N和Ce共掺杂TiO_2降解酸性蓝BRL、活性金黄K-2RA、弱酸性黑RB和酸性大红GR 4种染料废水,考察了催化剂用量、染料初始浓度、光照时间和pH值等对其降解率的影响。结果表明:B、N和Ce共掺杂TiO_2除了能使染料快速褪色外,还能将其完全矿化为CO_2,SO_4~(2-)和NH~+_4等离子。酸性大红GR染料和酸性蓝BRL在pH=5、催化剂用量50mg、初始浓度50mg/L、光照180min时降解率分别为98%和94.2%。pH=1、催化剂用量50mg、初始浓度40mg/L、光照时间180min时,活性金黄K-2RA的降解率达94.5%。弱酸性黑RB在pH=2、催化剂用量60mg、初始浓度20mg/L、光照时间210min时,降解率达到最大,为92.6%。     

活性竹炭对苯酚的吸附动力学

研究了30℃下活性竹炭对苯酚溶液的吸附动力学,考察了苯酚初始浓度和吸附剂粒径的影响,并用三种动力学模型进行了拟合.结果表明:活性竹炭对苯酚的吸附动力学过程可以用准二级模型进行很好的描述,拟合所得的初始吸附速率随着苯酚浓度的增加和竹炭粒径的减小而提高.颗粒内扩散模型分析表明,活性竹炭对苯酚溶液的吸附过程中,颗粒内扩散为主要速率控制步骤.     

利用稻杆衍生吸附剂去除液相中呋喃丹(英文)

以KOH为活化剂进行两段式活化程序,将废弃生物质材料转化为活性炭,并评估此活性炭吸对液相中农药(呋喃丹)的去除能力。结果表明,此活性炭具有大比表面积与高吸附能力可快速有效地去除液相中的呋喃丹。吸附前后的活性炭用扫描电子显微镜、元素分析仪与傅里叶变换红外光谱仪进行特征分析。活性炭的比表面积与平均孔径分别为1304.8 m2/g与2.39 nm。同时对不同的吸附参数进行批次分析,包括呋喃丹初始浓度,吸附时间、温度与酸碱度。最大吸附量(296.52mg/g)的吸附参数为90min、30℃、吸附剂剂量100mg/L、180 r/min、呋喃丹初始浓度200mg/L。根据三种平衡吸附等温线(Langmuir,Freundlich and Temkin)与动力学分析,Langmuir模式最符合此活性炭的吸附结果,伪二级动力学方程可预测此活性炭的吸附动力学。     

板栗壳对水中孔雀石绿和刚果红的吸附研究

以板栗壳作为吸附剂,研究其对模拟印染废水中孔雀石绿和刚果红的吸附性能。结果表明:在染料初始浓度100mg/L,板栗壳投加量2.0g/L,废水初始pH=7.0下,对孔雀石绿的去除率为95.20%;废水初始pH=5.0~8.0下,对刚果红的去除率为92.88%。将板栗壳吸附孔雀石绿和刚果红的过程用准一级动力学方程、准二级动力学方程、Elovich方程和双常数方程进行拟合,结果表明板栗壳对两种染料的吸附过程均符合准二阶动力学方程,说明该吸附过程以化学吸附为主;其等温吸附过程可以用Freundlich方程描述,说明该吸附以多分子层吸附为主。     

剩余污泥制活性炭及其应用研究进展

城市污水处理设施运行过程中,会产生大量的剩余污泥,处理不当会对环境造成很大的污染。综述了国内外制备污泥活性炭的技术,根据其在废水、废气治理中的研究现状,讨论了对废水中的重金属、高浓度难降解有机污染物的吸附效果,并阐述了对废气中的含硫化合物的去除情况。为了实现废物资源化和达到以废治废的目的,提出了将污水厂的剩余污泥用于制备污泥活性炭吸附污水处理过程中产生的恶臭气体的研究思路。     

Adsorption of heavy metals from wastewater with waste activated sludge

Abstract

The purpose of this study is the investigation of the adsorption of heavy metals from wastewater with waste activated sludge (WAS) so as to increase the operational flexibility of activated sludge processes for the shock loading problems of heavy metals. By contacting the raw wastewater with WAS, before it entered the activated sludge process unit, some heavy metals in the wastewater were removed, and the pH value of the acidic wastewater rose. Five metals, Cu, Zn, Ni, Cd and Pb, were studied, some factors which affected this biosorption phenomena were investigated, and expressions of the adsorption isotherms were discussed. A semi‐empirical mass transfer‐adsorption model was developed to describe the kinetic experimental data.     

剩余活性污泥的超声脱水及破解

文章从静态和动态研究了剩余活性污泥的超声脱水及污泥的破解。静态下,污泥的脱水应在低功率(以50W为例)短时间(7min)内进行,最高的脱水率(相对于未超声而言)可增加近16%;污泥破解应在高功率长时间下进行,本实验在250W的功率下连续处理20min,COD的增加值达到近1600mg/L;污泥的破解满足一级反应动力学。动态下,以低功率(50W)为例,脱水及破解曲线都比较平坦,污泥的总脱水率相对于未超声而言增加可达近23%;COD的增加值近似达1800mg/L。通过比较低功率下实验,动态实验效果明显优于静态实验。     

膜生物反应器处理冲厕海水的试验研究

主要研究了膜生物反应器对冲厕海水中主要污染物的处理效果以及盐度对生物反应器内微生物群落和活性污泥特性的影响.结果表明,微生物经培养驯化后能适应不同的海水盐度,膜生物反应器对冲厕海水中的COD和氨氮的去除率分别达到86%和93%.随着盐度的提高,污泥沉降性能变差.盐度的冲击对膜生物反应器处理效果有一定影响,系统需要较为恒定的盐度条件.     

Compartmentalizing anaerobic zone improves sludge settling property of enhanced biological phosphorus removal system under low sludge retention time

Abstract

The study investigated the effect of compartmentalization of anaerobic zone on sludge settling property in an enhanced biological phosphorus removal (EBPR) system. Continuous‐flow pilot‐plant experiments with synthetic influent were performed at varied anaerobic‐oxic volume ratios (V_an : V_o , 1 : 9 and 2 : 8), involving 5, 10 and 15 days of sludge retention times (SRTs). Experimental results indicated that, regardless of V_an : V_o and SRT, satisfactory removal of COD and phosphate were achieved during all test runs. However, extremely high sludge volume index (SVI) values were observed when there were 5 days of SRT. Further experiments with compartmentalization of anaerobic zone were therefore conducted to confirm the necessity of incorporating the kinetic selection mechanism of bulking control into an EBPR process operated at a low SRT. These results revealed that the two factors, V_an : V_o and anaerobic compartmentalization, had interaction with respect to sludge settling property in terms of SVI. When anaerobic retention time increased from 0.72hr to 1.36hr, compartmentalizing anaerobic zone significantly decreased the SVI value because of generating high COD concentration gradient and phosphate release in the anaerobic zone. This result implies that supplementing kinetic selection pressure of bulking control exhibits a critical influence on sludge settling when the EBPR process operates at a lower SRT.     

污泥制备活性炭对 Pb(Ⅱ)和Ni(Ⅱ)的吸附和回收利用

在静态条件下研究了用污泥制备的活性炭吸附剂去除水溶液中Pb(Ⅱ)、Ni(Ⅱ)的效果,考察了溶液pH值、吸附时间、吸附剂用量和Pb(Ⅱ)、Ni(Ⅱ)的初始浓度对去除率的影响.结果表明,污泥制备的活性炭吸附剂对Pb(Ⅱ)、Ni(Ⅱ)具有较强的吸附性能,pH值是影响吸附的主要因素;吸附过程符合Langmuir吸附等温式;在试验条件下,其对Pb(Ⅱ)具有更高的去除能力.还探讨了吸附Pb(Ⅱ)、Ni(Ⅱ)后回收铅和镍的可行性.     

Reduction of excess sludge production in sequencing batch reactor through incorporation of chlorine dioxide oxidation

In this study, chlorine dioxide (ClO₂) instead of chlorine (Cl₂) was proposed to minimize the formation of chlorine-based by-products and was incorporated into a sequencing batch reactor (SBR) for excess sludge reduction. The results showed that the sludge disintegrability of ClO₂ was excellent. The waste activated sludge at an initial concentration of 15 g MLSS/L was rapidly reduced by 36% using ClO₂ doses of 10 mg ClO₂/g dry sludge which was much lower than that obtained using Cl₂ based on similar sludge reduction efficiency. Maximum sludge disintegration was achieved at 10 mg ClO₂/g dry sludge for 40 min. ClO₂ oxidation can be successfully incorporated into a SBR for excess sludge reduction without significantly harming the bioreactor performance. The incorporation of ClO₂ oxidation resulted in a 58% reduction in excess sludge production, and the quality of the effluent was not significantly affected.     

Modelling Cr(VI) removal by a combined carbon-activated sludge system

The combined carbon-activated sludge process has been proposed as an alternative to protect the biomass against toxic substances in wastewaters; however, the information about the effect of powdered-activated carbon (PAC) addition in activated sludge reactors for the treatment of wastewaters containing Cr(VI) is limited. The objectives of the present study were: (a) to evaluate the removal of hexavalent chromium by (i) activated sludge microorganisms in aerobic batch reactors, (ii) powdered-activated carbon, and (iii) the combined action of powdered-activated carbon and biomass; (b) to propose mathematical models that interpret the experimental results. Different Cr(VI) removal systems were tested: (S1) biomass (activated sludge), (S2) PAC, and (S3) the combined activated carbon-biomass system. A Monod-based mathematical model was used to describe the kinetics of Cr(VI) removal in the system S1. A first-order kinetics with respect to Cr(VI) and PAC respectively, was proposed to model the removal of Cr(VI) in the system S2. Cr(VI) removal in the combined carbon-biomass system (S3) was faster than both Cr(VI) removal using PAC or activated sludge individually. Results showed that the removal of Cr(VI) using the activated carbon-biomass system (S3) was adequately described by combining the kinetic equations proposed for the systems S1 and S2.     

超声破解联合湿法检测活性污泥中CODCr的研究

准确测定活性污泥中化学需氧量(Chemical Oxygen Demand, COD_Cr)含量,是实现污泥资源化利用的重要条件。文章提出一种超声破解联合湿法测定活性污泥中COD_Cr含量的检测方法。基于单因素实验结果,以COD_Cr浓度作为响应值,采用响应曲面法考察了污泥混合液的稀释倍数、超声功率和超声时间3个因素间单独及交互作用,并对影响因素进行了评估。结果表明,取样量为10 mL,稀释倍数为225倍,超声时间为18 min,超声功率为720 W时,样品平行测定的相对标准偏差小于等于2.00 %,加标回收率为96.51 %~105.32 %,测定结果的准确度、精密度较高。光学显微镜照片和激光粒度仪分析表明,超声破解能够有效破碎微生物细胞的絮体结构,显著降低污泥颗粒粒径,减少污泥取样过程中的误差。对不同f的污泥样品,COD_Cr测定值与理论值相关性拟合曲线的拟合值R²≥0.9961。研究结果证明超声破解联合湿法测定活性污泥中COD_Cr具有良好的可靠性和经济性。     

Effect of chemical composition on the flocculation dynamics of latex-based synthetic activated sludge

This study investigates the effect of calcium, alginate, fibrous cellulose, and pH on the flocculation dynamics and final properties of synthetic activated sludges. A laboratory-scale batch reactor, fed with standard synthetic sludges was used. The effects of varying calcium concentration (5-25 mM), alginate concentration (25-125 mg/L), fibrous cellulose concentration (0.2-0.8 g/L) and pH (3-9) on the sludge characteristics were studied by varying one parameter whilst keeping the others constant. The results from experiments indicated that the calcium, alginate, fibrous cellulose, and pH had the critical effect on the aggregation rate, flocs size, and made the improvement of the final properties of sludge. Dynamic measurements have established the optimum conditions for floc formation and can accurately reflect the state of formation of the synthetic activated sludge flocs. These correlate well with measurements of settleability and turbidity of the synthetic activated sludge. The results of this study support the bonding theory and indicate that formation of cations-polymer complexes and polymer gelation are important means of flocculation. The development of synthetic activated sludges is suggested also to be a possible surrogate for studying the final properties of activated sludge.