臭氧催化氧化处理制药废水连续性实验研究

采用NixO-FxO/陶粒催化剂在大高径比的管式反应器中进行臭氧催化氧化连续性实验,研究催化剂投加量、臭氧投加量、反应停留时间、气液接触方式等工艺条件对制药废水的处理效果和稳定性的影响。实验表明,催化氧化连续实验最佳工艺条件为:停留时间90 min,臭氧气体通量为1 L/min,臭氧浓度为96.61 mg/L,臭氧利用率可达到92.8%左右,气液接触方式逆流略优于并流效果。在臭氧催化氧化连续运行96 h,臭氧催化氧化去除制药废水COD可稳定在58%以上。     

臭氧催化氧化处理制药废水连续性实验研究

采用NixO-FxO/陶粒催化剂在大高径比的管式反应器中进行臭氧催化氧化连续性实验,研究催化剂投加量、臭氧投加量、反应停留时间、气液接触方式等工艺条件对制药废水的处理效果和稳定性的影响。实验表明,催化氧化连续实验最佳工艺条件为:停留时间90 min,臭氧气体通量为1 L/min,臭氧浓度为96.61 mg/L,臭氧利用率可达到92.8%左右,气液接触方式逆流略优于并流效果。在臭氧催化氧化连续运行96 h,臭氧催化氧化去除制药废水COD可稳定在58%以上。     

Treatment of dairy wastewater by electrocoagulation process: Advantages of combined iron/aluminum electrodes

ABSTRACT

The objective was to assess the efficiency of electrode material in an electrocoagulation (EC) process for wastewater treatment by comparing the efficiency of aluminum (Al–Al), iron (Fe–Fe) and combined Fe–Al electrodes. The treatment of synthetic dairy wastewater, characterized by high levels of 5-day biological oxygen demand (BOD₅) and chemical oxygen demand (COD), was used to compare electrode materials. Experimental results showed that all electrodes materials achieved the same final removal yield in the range of current studied (55% COD, 60% total organic carbon, 90% total nitrogen, and nearly 100% turbidity) when equilibrium was achieved. But at fixed current density and initial concentration of dairy waste, the Al–Al assembly exhibited the fastest elimination, whereas the slowest removal rate was observed with the Fe–Fe electrodes, even though adsorption was always the main removal mechanism. Finally, an Fe–Al system using an Fe anode with an Al cathode emerged as a techno-economic trade-off because of the low price of iron: both metals contributed to the removal of dairy waste, and the treatment time to achieve equilibrium values was closer to the Al–Al assembly at fixed current density. Moreover, experimental results proved the additivity of the mechanisms reported for Al–Al and Fe–Fe systems with Fe–Al.     

电絮凝法处理含油废水的研究

通过石墨-石墨、铝-石墨、铅-石墨、铁-石墨和铝-铁等5种电极组合分别处理含32#机油的废水。研究发现，铝-石墨为最佳电极组合，通过正交实验设计，选择固体悬浮物(SS)、化学需氧量(COD)和含油量的去除率较大的条件是：电解质(NaCl)为3g，电解电压为10V，电解时间为25min。     

Treatment of paint manufacturing wastewater by electrocoagulation

Treatability of paint manufacturing wastewater (PMW) by electrocoagulation (EC) process was investigated. Effects of operating parameters for the EC process such as electrode type (Al or Fe), initial pH (2–10), current density (5–80 A/m²) and operating time (0–50 min) were evaluated for optimum operating conditions. The highest removal efficiencies for COD and TOC in PMW were obtained with 93% and 88% for Fe and 94% and 89% for Al electrodes at the optimum conditions (35 A/m², 15 min and pH 6.95). Operating costs for removal of PMW at the optimum conditions were calculated for Fe and Al electrodes as 0.187 €/m³ and 0.129 €/m³. Toxicity test was carried out to obtain information about toxic effect of the raw and treated wastewaters at optimum operating conditions. The samples measured by respirometric method contained hardly toxicities. Performance of Al electrode was better than that of Fe electrode in terms of removal efficiency and operating cost.     

Treatment of potato chips manufacturing wastewater by electrocoagulation

Treatment of wastewater from potato chips manufacturing by electrocoagulation (EC) was investigated. Experiments were conducted to determine the optimum operating conditions such as electrode type, pH, current density and retention time. Aluminium and iron electrodes were used, and aluminium electrodes were found to be more suitable since it had a higher removal rate of COD, turbidity and suspended solids than the iron electrode. The removal efficiencies of COD and turbidity were high, being 60% and 98%, respectively, with retention time < 40 min. 0.05–1.75 kg (per kg COD removed) of dried sludge was removed. COD removal kinetics during EC process was described by a macro-kinetics model. Results from the kinetic studies showed that the kinetic data fit the second-order kinetic model well. The operating costs investigated in the present study were the energy cost of EC and the material cost due to the consumption of aluminium electrode. Operating costs were varied in the range of 0.48 to 5.42 $/m³ and 0.62 to 6.32 $/m³ wastewater treated at 20–300 A/m² and 5–40 min, respectively. The energy consumption was 4 kWh/m³ for wastewater treated less than 8 min under typical operating conditions.     

电絮凝法处理含锰废水试验研究

采用周期换向电絮凝法处理含锰废水,考察了初始pH值、电流密度、初始浓度等因素对处理效果的影响.结果表明,当初始pH值为9.0,总锰初始质量浓度为40 mg/L,处理时间为5 min,电流密度为23.81 A/m2,电极换向周期为15 min时,总锰的去除率超过98％.电絮凝出水经曝气、絮凝和过滤处理后满足GB18918-2002《城镇污水处理厂污染物排放标准》的要求.     

铝柱撑改性膨润土处理电镀废水中Cr6+的实验研究

以膨润土为原料制备了铝柱撑改性膨润土,并研究了不同影响因素对铝柱撑改性膨润土去除电镀废水中Cr6+的影响.结果表明:铝柱撑改性膨润土对Cr6+的去除率明显优于膨润土原土;废水的pH、吸附时间和膨润土投加量对Cr6+的去除率影响较大;pH＝4,吸附时间为40 min,投加质量浓度为40 g/L,铝柱撑改性膨润土对Cr6+的去除率达到最大86.1％;铝柱撑改性膨润土对电镀废水中Cr6+的吸附符合Langmuir吸附等温方程.     

光合细菌利用有机废水连续产氢的试验研究

为考察光合细菌连续性生物制氢过程中碳源浓度、水力停留时间等因素对连续运行稳定性能和制氢量的影响,通过改变碳源浓度和水力停留时间来测定产氢量以及产氢率,确定最佳的连续运行条件。结果表明:光合细菌利用含糖废水为基质进行连续性生物制氢过程中,在最佳温度为30℃、最佳光照强度为3 000 Lux的情况下,且当葡萄糖质量浓度为12 g/L,水力停留时间为72 h时,产氢效率最高,连续产氢速率达45 m L/h。     

Removal of oil from biodiesel wastewater by electrocoagulation method

An attempt has been made to remove oil and grease (O&G) from biodiesel wastewater as well as O&G and turbidity in the presence of H₂O₂ and polyaluminum chloride (PAC), as a coagulant-aid by an electrochemical method using iron as sacrificial electrodes. The effects of current density, amount of hydrogen peroxide using as an oxidizing agent and addition of coagulant-aid, on percent removal and energy consumption have been investigated. The removal efficiency of O&G was in the range of 62–86%, whereas O&G removal was 100% in the current density range of 10–12.5 mAcm^?2 depending on the concentrations of H₂O₂ and coagulant aid. It is obtained that electrocoagulation in the absence of coagulant aid and oxidant is not too efficient for the treatment of this type of wastewater.     

低Reynolds数下水平管降膜滴状流动的实验研究

为了充分了解水平管降膜滴状流动现象,以水为实验流体,采用高速高清摄像仪对不同管距下水平管降膜滴状流动进行了可视化的实验研究。实验观察了低Reynolds数Re≤200、管间距s≤40 mm 范围内的管间滴状流动过程。根据流动形态的特征,将滴状流动划分为堆积滴状流、不完全滴状流、吊坠滴状流、完全滴状流和不完全回缩滴状流。依据实验结果,绘制了滴状流动形态分区图。提出了分离长度的概念,并讨论了流量对分离长度的影响。研究了低Reynolds数下液滴流动的滴落点间距与流量的关系。结果表明,滴状流的管间流动形态不仅受流量的影响,同时也受管间距的影响。分离长度随着Re的增大呈两段式线性增大。液滴流动的滴落点间距在Re≤100范围内随Re增大而减小,在100<Re≤200范围内趋于平稳。此外,分别建立了分离长度和滴落点间距与Re的关系式。     

电絮凝技术处理油田含油污水的研究

针对油田开采过程中产生的含油污水,开展电絮凝技术处理含油污水的研究。考察了电流密度、极板间距以及电解时间等因素对污水除油效果的影响。实验结果表明,在电流密度为7 mA/cm2,电解时间为20 min,极板间距为2 cm时,含油污水脱油率达到92%。在优化条件下研究了污水含油量和水质矿化度对电絮凝除油效果的影响,初始油质量浓度越低,处理后污水含油量越少;污水矿化度越大,脱油效果越差。     

Treatment of textile dyeing wastewater by electrocoagulation using Fe and Al electrodes: optimisation of operating parameters using central composite design

Textile dyeing wastewater was treated by electrocoagulation using aluminium and iron plate electrodes. Response surface methodology and central composite design were applied in the experiments and in statistical data analysis. A current density of 30–100 A m^?2, an initial pH of 4–8, and an operating time of 10–40 min were chosen as independent variables, and the chemical oxygen demand, total organic carbon, and turbidity removal efficiencies and the operating cost were selected as responses in the electrocoagulation process. The developed quadratic models for the responses and the experimental data were in good agreement with model predictions statistically (R² ≥ 0.92, Adj R² ≥ 0.82, and Prob > F < 0.004). The optimised operating variables (initial pH, current density, and operating time) and the maximum total organic carbon, chemical oxygen demand, and turbidity removal efficiencies for textile dyeing wastewater were 5.5, 63.2 A m^?2, 30.4 min, 77%, 82%, and 94% for the iron electrode and 5.6, 52.5 A m^?2, 33.9 min, 68%, 69% and 99% for the aluminium electrode respectively. Minimum operating costs for the iron and aluminium electrodes under optimum conditions were €2.1 m^?3 (€1.0 kg^?1 COD) and €2.4 m^?3 (€1.6 kg^?1 COD). The iron electrode was found to be superior to the aluminium electrode in terms of removal efficiencies and operating cost for the treatment of textile dyeing wastewater.     

Experimental investigation of continuous single‐phase rimming flow in a horizontal rotating cylinder

Rimming flow of water that leads to a thin film onto the inner surface of a horizontally rotating cylinder is studied in this work. At higher rotational speeds, axial flow of uniform thin film is established inside the rotating cylinder. Film thickness measurements under different flow conditions were performed in the annular flow regime using an optical interferometric technique. Dimensional analysis was also performed to understand the parametric dependence of key parameters involved in the rimming flow of water inside a horizontal rotating cylinder and expressions to determine average film thickness and average residence time are also presented. This study will provide a basis to estimate the transport characteristics in the thin film inside the horizontal rotating cylinder. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3939–3950, 2014     

超滤膜处理含聚合物采油废水的实验研究

经过常规沉降和砂滤工艺处理后的采油废水,因其含油量、悬浮物和浊度过高而无法达到配制聚合物的用水标准.为了使含油废水符合配制聚合物的用水要求,采用聚偏氟乙烯超滤膜对大庆油田含油废水进行处理,结果表明,膜滤出水的油和悬浮物质量浓度均小于1.0 mg/L,去除率可达到95%,浊度低于1.0 NTU,去除率达到90%以上.同时对膜的清洗进行了实验,用自制以十二烷基苯磺酸钠为主的清洗药剂对膜进行清洗,能使膜通量基本恢复,有效延长了膜的使用寿命.     

生物絮凝剂处理制革废水的试验研究

由污泥中筛选的微生物可作为絮凝剂处理制革废水.制革废水中含COD为3 200mg/L、SS为3 100mg/L,Cr3 为70 mg/L,当温度为25℃、pH为7.0时,絮凝剂按V(絮凝剂):V(废水)=0.2投加时,COD、SS、Cr3 的去除率分别为72.4%、62%、63.5%,且絮凝剂本身对环境无害.     

黄姜皂素废水厌氧处理间歇试验研究

针对黄姜皂素废水的特征采用三种不同的厌氧处理工艺对其进行静态厌氧处理试验，在试验条件相同的条件下，测得三种厌氧工艺的处理效果。试验表明，三段式两相厌氧工艺处理后的出水残留COD在相同时段内明显低于两相厌氧工艺和单级厌氧工艺。通过对其处理过程的产气动力学分析，得出三种厌氧工艺的动力学参数，并分析了三段式两相厌氧工艺优于其他厌氧工艺的机理及缘由。     

改性硅藻土处理含铜废水的试验研究

采用氢氧化钠改性的硅藻土作为吸附材料,研究了吸附剂用量、搅拌时间、pH值以及废水浓度等因素对吸附效果的影响。结果表明,在100 mL Cu2+的质量浓度为10.49 mg/L,改性硅藻土投加量为3.5 g,pH值为8.5,吸附时间为30 min的条件下,废水中Cu2+的去除率最高可达97.93%,出水Cu2+的质量浓度低于0.22 mg/L,达到了GB 8978—1996《污水综合排放标准》一级标准的要求。     

水平管内气液段塞流液塞发展特性实验研究

Slug initiation and subsequem evolution along a 5.0 cm ID, 16m long horizomal pipe are experimentally studied. The transient characteristics of interfacial structures are described by using simultaneous measuremeres of the liquid height at multiple locations along the pipe. Various effects of superficial gas and liquid velocities and pressure oscillation on the slug initiation and evolution along the pipe are illustrated. It is found that the slug is initiated by a deterministic orocess with reolenishmem and deoletion of liquid near the inlet for the superficial gas velocity USG〈3.0m·s^-1 and by a stochastic process with wave coalescence along the pipe for USG〉3.0m·s^-1.The evolution of the slugs is strongly attected by superhclal gas and liquid veloclties for USG〈3.0m·s^-1 but weakly affected by the superficial gas velocity for USG〉3.0 m·s . The suppression of pressure oscillation at the pipe inlet significantly delays the onset of slugging, with slugs forming postponed further downstream. The slug frequency at the outlet is, however, not affected by the variation in the pressure oscillation.     

高压脉冲电絮凝处理综合电镀废水的试验研究

采用高压脉冲电絮凝技术处理某电镀厂的电镀废水,考察了高压脉冲电絮凝设备对Cu2＋、Ni2＋、CN-和CODCr的去除效果.结果表明,高压脉冲电絮凝技术对电镀综合废水的处理效果显著,Cu2＋、Ni2＋、CN-和CODCr的去除率分别可以达到99.80％、99.70％、99.68％和67.45％,达到GB 8978-1996《污水综合排放标准》的要求.该高压脉冲电絮凝技术处理电镀废水具有处理效率高、速度快、占地面积小、操作方便的特点,有良好的工程应用前景.