Application of O3 and O3/H2O2 as post-treatment processes for color removal in swine wastewater from a membrane filtration system

This study was aimed to evaluate the use of ozone (O₃) alone and peroxone (a combination of ozone and hydrogen peroxide; O₃/H₂O₂) as post-treatment processes for color removal in swine wastewater from a membrane filtration system. Results showed that the application of ozone-alone process or the peroxone process could reduce both capital and operating costs compared to reverse osmosis (RO) treatment. Of the two oxidation processes, the ozone-alone process was the most effective for treating nanofiltration (NF)-filtered wastewater, while the peroxone process was the most effective for treating ultrafiltration (UF)-filtered wastewater.     

A combined photocatalytic slurry reactor–immersed membrane module system for advanced wastewater treatment

Photocatalysis with titanium dioxide semiconductor catalyst can effectively degrade recalcitrant organic pollutants present in biologically treated sewage effluents. Focusing on process efficiency and sustainability within a broader program, this study presents results obtained with a bench-scale hybrid treatment system. The process train comprised of a slurry (suspension) type continuous photocatalytic (CP) system and an immersed hollow fibre membrane micro-ultrafilter (MF/UF) unit. The CP reactor charged with 1 g/L P-25 catalyst removed 63% dissolved organic carbon (DOC) from a synthetic wastewater (representing biologically treated sewage effluent). The addition of 0.05 g/L of powdered activated carbon (PAC) increased DOC removal up to 76%. The start-up times to achieve 60% DOC removal were 31 min and 15 min, respectively. These results show a 16 times improvement in volumetric load over a comparable batch reactor system used in previous studies by our group.Slurry type photocatalytic reactors need subsequent particle separation to retain the catalyst in the system and allow the discharge of treated effluent. The immersed membrane module accomplished this without prior slurry settling step. Membrane feed pre-treatment with pH adjustment and particle charge neutralisation with aluminium chloride coagulant led to improved critical membrane fluxes, 15.25 L/m² h and 19.05 L/m² h, respectively. In each experiment MF/UF produced near zero turbidity permeate, completely retained the photocatalyst, and flocculation also improved the efficiency of DOC removal. Membrane fouling was controlled by particle aggregation rather than feed DOC levels, but the latter had significant impact on coagulant demand. The complete treatment train achieved up to 92% DOC reduction with 12 mg/L AlCl₃ dosage using in-line coagulation conditions. The results show that in-line coagulation offers a simple yet effective means to improve the performance of slurry type photocatalytic–MF/UF hybrid systems for advanced water and wastewater treatment applications.     

氧化-絮凝-A/O处理甲基多巴生产废水研究

甲基多巴是一种降压药物,其生产废水具有高色度、高有机物浓度和生物难降解的特性.采用Fenton氧化-PAM絮凝-A/O生化工艺处理该废水.Fenton氧化处理的优化条件为:pH 5.0,n(Fe2 )∶n(H2O2)=1∶4,H2O2和绿矾投加质量浓度分别为5.0 g/L和10.2 g/U,反应时间2.0 h.PAM絮凝处理的优化条件为:pH 7.0,投加量16.7mg/L.经过Fenton氧化-PAM絮凝处理,CODCr去除率达到74%,脱色率达95%,B/C由0.17升到0.38,废水的可生化性明显提高.后续采用A/O工艺进一步处理,可再去除70%～80%的CODCr.     

Multistage-batch bipolar membrane electrodialysis for base production from high-salinity wastewater

Bipolar membrane electrodialysis (BMED) is considered a state-of-the-art technology for the conversion of salts into acids and bases. However, the low concentration of base generated from a traditional BMED process may limit the viability of this technology for a large-scale application. Herein, we report an especially designed multistage-batch (two/three-stage-batch) BMED process to increase the base concentration by adjusting different volume ratios in the acid (V_acid), base (V_base), and salt compartments (V_salt). The findings indicated that performance of the two-stage-batch with a volume ratio of V_acid:V_base:V_salt = 1:1:5 was superior in comparison to the three-stage-batch with a volume ratio of V_acid:V_base:V_salt = 1:1:2. Besides, the base concentration could be further increased by exchanging the acid produced in the acid compartment with fresh water in the second stage-batch process. With the two-stage-batch BMED, the maximum concentration of the base can be obtained up to 3.40 mol∙L^–1, which was higher than the most reported base production by BMED. The low energy consumption and high current efficiency further authenticate that the designed process is reliable, cost-effective, and more productive to convert saline water into valuable industrial commodities.     

IC反应器处理马铃薯淀粉生产废水的试验研究

试验采用超滤-IC反应器-MBR工艺处理马铃薯淀粉生产废水,重点研究了IC反应器处理马铃薯淀粉废水的工艺参数。结果表明,在常温下,当进水COD的质量浓度为6000～9000mg/L、HRT为5h、容积负荷为23.62kg[COD]/(m3·d)时,IC反应器对COD的去除率为91.43%。采用该工艺处理马铃薯淀粉生产废水完全可以达到废水回用的目的。     

铜酞菁生产废酸废水综合治理方案探讨

某铜酞菁生产企业将产生的废酸、废水混合后采用生化处理法,其处理成本高、运行效果差。通过调查废酸、废水的来源、水质、水量,提出废酸回收、酞菁蓝漂洗水压滤回用及混合废水的资源化三项方案。方案不但减少了原料消耗、治理了废酸废水,而且回收了高价值铜泥,同时利用废酸吸收生产工艺中的高含氨废气,生产副产品硫酸铵,实现了废物的资源化利用,达到了以废治废的目的,符合循环经济的理念。     

絮凝-膜过滤处理生活污水的研究

以生活污水为处理对象,选用了5种无机絮凝剂和2种有机絮凝剂进行了单一和复合处理时的对比研究,并考察了pH值、投加顺序对COD去除率的影响,在此基础上,探讨了絮凝和膜过滤结合对生活污水的处理效果。研究表明,在三氯化铁和有机絮凝剂复合的最佳絮凝条件下,COD的去除率达65％左右;在膜分离过程中引入絮凝处理,能显著提高处理效果,COD去除率在75％左右,同时,絮凝处理后的膜通量迅速提高。     

维生素B1制药废水处理方法探试

针对维生素B1制药废水有机物浓度高、悬浮物高、色度深、难降解的特点,采用混凝-氧化-铁炭微电解工艺进行处理。试验对混凝剂的种类与用量、pH值、微电解的运行方式及炭铁体积比等进行了优化,最佳工况为:氯化铁用量为150 mg/L,次氯酸钠用量为40 mL/L,炭铁体积比为1∶1.5,曝气加搅拌的微电解方式运行40 min。在进水COD、SS的质量浓度分别为1 500、2 650 mg/L,色度为80倍时,经该工艺处理后,出水COD的质量浓度为164 mg/L,去除率为89.1%,悬浮物和色度去除率分别为97.6%、98%,达到《污水综合排放标准》(GB8978-1996)二级标准。     

双极膜电渗析法麦草畏生产废水的资源化利用研究

采用双极膜电渗析（bipolar membrane electrodialysis,BMED）将麦草畏生产废水中的NaCl转化为HCl和NaOH回用于农药生产,实现农药废水的资源化利用。首先进行了BMED法处理单组分NaCl溶液体系的110 min间歇运行实验来探索最优操作条件,结果表明,当NaCl初始浓度为160 g/L,电流密度为70 mA/cm²,初始酸碱室浓度为0.075 mol/L时,产物HCl、NaOH的浓度能分别达到1.98 mol/L和 2.06 mol/L,且此时的电流效率较高,达到42.74%。然后考虑实际废水的COD指标主要是甲醇造成的,所以用含不同浓度甲醇的NaCl溶液模拟实际农药废水,实验结束后在酸、碱隔室中检测到少量的甲醇,表明其在BMED运行过程中存在一定程度的渗透,但未对膜堆性能造成明显影响。最后用BMED处理经过预处理后含有机物的麦草畏生产废水,发现在操作时间内膜堆性能与处理高浓度单组分NaCl溶液情况类似,证实BMED法处理麦草畏生产废水并实现资源化利用的可行性。     

膜生物反应器处理己内酰胺生产废水

为了更加有效地提高己内酰胺生产废水生化处理装置抗高浓度废水冲击能力,在原A/O处理系统中采用膜生物反应器技术对己内酰胺生产废水进行生化处理。工业应用结果表明:由于己内酰胺废水中氨氮含量较高,膜生物反应器进水pH值应该控制在8.5～9.5,以保证系统有效的硝化反应,去除氨氮;当进水COD、氨氮的质量浓度分别控制在2 000、200 mg/L以内时,出水COD、氨氮的质量浓度分别小于70、15 mg/L。处理后的水质能够达到国家一级排放标准。     

Performances of RO and NF processes for wastewater reuse: Tertiary treatment after a conventional activated sludge or a membrane bioreactor

Wastewater reclamation requires processes and technologies having the ability to reduce the presence of micropollutants which are not wholly treated in conventional WWTP. Due to the complexity of membrane-solute interactions and the diversity of secondary treatment effluent (STE) matrices, deeper investigations are required to identify the major foulant species and more specifically their behaviour at high concentration in real waters. This study investigates the rejection and fouling potential of nanofiltration (NF) and low-pressure reverse osmosis (RO) membranes with two STEs sampled from i) a conventional activated sludge process coupled with ultrafiltration (CAS-UF) and from ii) a membrane bioreactor MBR (AquaRM^®, SAUR (France)). Whatever the origin of the effluent, RO seems to be the best solution to prevent pollution of tertiary effluents (expected result) but also to obtain low fouling levels. The different composition and molecular weight distribution of MBR and CAS-UF effluents can explain the different fouling behaviours that were observed.     

小麦谷朊粉及淀粉生产废水处理中超滤膜的选择

通过实验研究了不同截留相对分子质量和膜材料的超滤膜在超滤小麦谷朊粉及淀粉生产废水时的渗透通量、膜衰减系数、蛋白质截留率、还原糖透过率。根据实验结果综合分析表明:PS-10膜浓缩小麦淀粉废水时膜衰减系数为0.1841、蛋白质截留率为72.2%、还原糖透过率为86.2%,是超滤浓缩分离此废水的适宜用膜。     

Fluidized bed magnetic ion exchange (MIEX®) as pre-treatment process for a submerged membrane reactor in wastewater treatment and reuse

Magnetic ion exchange (MIEX®) resin can effectively remove significant amounts of organic matter from biologically treated sewage effluent. The MIEX® process has mainly been used as a batch process, which requires a large area for accommodating both contact tank and settling tank in the treatment process. In this study, a fluidized bed MIEX® reactor (a semi-continuous process) was used as a pre-treatment for a submerged membrane. When used as a pre-treatment for a submerged membrane, the fluidized bed MIEX® contactor could remove a significant amount of organic matter in the wastewater (80% removal). This pre-treatment helped to reduce membrane fouling and keep transmembrane pressure low during the membrane operation of 8 h (less than 19 kPa). The regeneration of MIEX® resin (number of regeneration, regeneration time, etc.) did not have any adverse effect on the organic removal by MIEX®.     

膜处理工艺在焦化废水深度处理中的应用

针对焦化废水生化处理后出水成分复杂、污染物种类多、可生化性差等特点,应用超滤、纳滤膜处理工艺对其进行深度处理,出水可回用于循环水。从进水水质、运行方式及膜清洗方面对影响膜处理系统运行的因素进行了总结。     

膜技术在钢铁废水处理及回用中的应用

对膜技术在钢铁废水深度处理与回用应用进行分析,探讨了膜技术在处理钢铁企业废水处理中的优缺点和发展趋势,提出对膜技术在钢铁废水处理中回用应用的一些建议和展望。     

Removal of heavy metals from wastewater by membrane processes: a comparative study

Wastewater containing copper and cadmium can be produced by several industries. The application of both reverse osmosis (RO) and nanofiltration (NF) technologies for the treatment of wastewater containing copper and cadmium ions to reduce fresh water consumption and environmental degradation was investigated. Synthetic wastewater samples containing Cu²⁺ and Cd²⁺ ions at various concentrations were prepared and subjected to treatment by RO and NF in the laboratory. The results showed that high removal efficiency of the heavy metals could be achieved by RO process (98% and 99% for copper and cadmium, respectively). NF, however, was capable of removing more than 90% of the copper ions existing in the feed water. The effectiveness of RO and NF membranes in treating wastewater containing more than one heavy metal was also investigated. The results showed that the RO membrane was capable of treating wastewater with an initial concentration of 500 ppm and reducing the ion concentration to about 3 ppm (99.4% removal), while the average removal efficiency of NF was 97%. The low level of the heavy metals concentration in the permeate implies that water with good quality could be reclaimed for further reuse.     

膜分离技术处理磷酸铁生产废水实验研究

磷酸铁生产废水因含大量低浓度铵根、硫酸根等杂质离子,增加了工业处理难度,影响了磷酸铁生产企业的可持续性发展。采用膜分离技术对湖南某电池级磷酸铁生产企业的工业废水进行了处理效果试验研究,选用国内某海水淡化膜,在废水进水质量分数为0.519%、pH为7、温度为20℃、操作压力为1.727MPa,并控制产水率为75%的条件下,处理后淡水中铵根离子浓度降为61.22mg/kg、硫酸根离子浓度降为147.63mg/kg、盐浓度降为0.02%,盐脱除率达到96.15%。     

H/O工艺处理维生素B1生产废水影响因素研究

采用水解酸化-好氧氧化-砂滤串联工艺处理维生素B1制药废水,试验分别考察了pH、温度、滤速、溶解氧以及污泥负荷对整个工艺处理效果的影响.结果表明,原废水BOD/COD约为0.14,属难生物降解废水,经水解酸化处理后,出水BOD/COD可达0.43,可生化性大大提高.维持好氧氧化工段进水COD质量浓度和MLSS的COD负荷分别在3 000mg/L和0.4～0.5 kg/(kg·d)时,系统运行稳定性好,COD去除率均在80.0%以上.     

汽车钢板冷轧生产废水处理工程设计

介绍了唐钢汽车板冷轧过程中产生的高浓度含油乳化液废水、平整液废水、含碱废水工艺流程及设计参数。含油乳化液废水与平整液废水采用气浮-厌氧预处理,含碱废水采用序进气浮预处理,然后再合并采用缺氧-好氧MBR生化处理工艺流程。目前工程运行稳定,出水COD_(Cr)的质量浓度不超过30 mg/L,出水SS的质量浓度不超过20 mg/L,满足要求。     

One-step cleaning method for flux recovery of an ultrafiltration membrane fouled by banknote printing works wastewater

A method was developed to clean ultrafiltration (UF) membranes fouled by banknote printing works wastewater.The cleaning agent was comprised of 0.7 wt.% NaOH, 0.8 wt.% Na₂EDTA, 0.3 wt.% Turkey red oil and 98.2 wt.% de-ionized water. Membrane flux recovered adequately when the cleaning agent was circulated for 20–30 min at 1.5 m/s and 50–60°C. The membrane surfaces before and after cleaning were characterized by SEM/EDX. The spent cleaning agent was analyzed by TOC and ICP. The results showed foulants were removed from the fouled membrane by the cleaning. Pilot-scale experiments were also conducted to validate the efficiency of the cleaning method. This one-step cleaning method replaced an existing four-step cleaning method and was employed to clean OF units in banknote printing works wastewater plants.