水化深度处理渗滤液尾水中的有机物

利用水泥的水化过程易受有机物影响的特点,采用硅酸盐水泥深度处理了垃圾渗滤液膜生物反应器(MBR)工艺出水,考察了不同因素,如投加量、初始pH、反应时间及振荡速率等对于渗滤液尾水中有机物的去除效果以及最佳工艺条件,并分析了渗滤液尾水中有机物的去除机理。结果表明,水化过程对渗滤液尾水中的有机物去除性能良好,且对不同有机物具有一定的选择性,尤其对具有近紫外区(200～400 nm)吸收峰特征的有机物去除效果更佳,同时发现,当投加量为50 g/L、pH=8.3(原渗滤液pH)、反应时间为24 h和振荡速度为200 r/min时,去除效果最佳,其COD、TOC和UV254的平均去除率分别达到55.6%、62.1%和68.8%。     

电絮凝处理牛仔布印染废水

用铁分别作为电絮凝反应系统的阴极和阳极,研究电絮凝法对牛仔布印染废水的处理效果。考察了电极电压、反应时间和pH等因素对电絮凝法去除实验所用废水中COD和色度效果的影响。结果表明,电极电压和反应时间是主要的影响因素,pH次之。电极电压24 V,反应时间35 min,pH为7.4时,脱色率可达99%,COD去除率在70%左右,处理效果最佳。因此,电絮凝法可以作为印染废水的预处理工艺,有效降低废水COD和色度。     

电絮凝处理三次采油废水

采用电絮凝技术对含PAM的三次采油废水进行处理,研究了不同极板、pH、电流密度、极板间距、搅拌速度、反应时间以及极性交换周期对大庆三次采油废水处理效果的影响。通过处理效果和成本分析,铝作为极板时处理效果要优于铁板,最佳实验条件下COD去除率达到了94.6%。同时对三次采油废水的主要性质和电絮凝处理三次采油废水的作用机理进行了分析,发现COD主要通过絮凝沉降作用去除,而电化学氧化作用和气浮作用对COD的去除效果并不显著。与普通化学混凝法相比,电絮凝处理三次采油废水在处理效果和成本方面有着独特的优势。     

US/UV-Fenton体系处理不同工段的印染废水

研究了US/UV-Fenton体系处理废水的规律,首先以亚甲基蓝为模拟污染物,探索US/UV-Fenton体系对模拟废水的去除效果;通过对比不同时间、不同pH值条件下Fenton、US/UV-Fenton体系对模拟废水去除效果,表明US/UV-Fenton体系明显优于Fenton体系。以此为依据,采用US/UV-Fenton体系分别处理调节池出水、二沉池出水2个工段的废水,研究了US/UV-Fenton体系的实际应用价值。结果表明:pH值是影响该体系降解效果最显著的因素,考虑经济和时间成本,分别确定了作为预处理工艺和深度处理工艺的最佳参数条件;最佳条件下,对调节池废水COD、TOC去除率达到86.6%、70.74%,可生化性(BOD5/COD)得到改善,有利于进一步生化处理;对二沉池废水COD、TOC去除率分别为73.88%、64.3%。     

铁碳微电解/H_2O_2耦合类Fenton法深度处理制药废水

采用铁碳微电解/H2O2耦合类Fenton法深度处理制药废水,考察不同铁碳比、H2O2投加量、溶液p H及反应时间对COD去除效果的影响,通过单因素实验和正交实验确定最优条件并与铁碳微电解法的去除效果进行对比。结果表明,各因素对COD的去除效果均呈现先增加后降低或趋于稳定的趋势,且对去除效果的影响顺序为:Fe/CH2O2投加量溶液p H反应时间;在固液比为1∶10的条件下,Fe/C(质量比)为1∶1,溶液p H为2.5,反应时间为60 min,H2O2(30%)投加量为12.24 mmol/L时对COD的去除效率最高,可达71.56%;H2O2对铁碳微电解法有显著的加强作用。     

内电解-水解酸化-接触氧化-氧化絮凝处理印染废水研究

采用内电解-水解酸化-接触氧化-氧化絮凝处理印染废水,考察了内电解反应中进水pH、反应时间、反应温度、鲍尔环填料中铁粉与焦炭质量比(简称Fe/C)对废水COD和色度去除效果的影响;在实验所得最佳条件下,内电解反应对废水中NH3-N和TP的去除效果;水解酸化-接触氧化对内电解出水的COD和NH3-N的去除效果及反应前后的...     

UV/Fenton技术处理某工厂高浓度乳化油废水

研究了UV/Fenton技术对高浓度金属清洗乳化油废水的处理效果,考察了亚铁与双氧水浓度、pH、反应时间和搅拌对COD去除效果的影响。实验结果表明,UV/Fenton技术对高浓度乳化油废水(COD平均浓度为35 000 mg/L)具有较高的去除效果,最佳工艺条件为:亚铁与双氧水浓度分别为2 400 mg/L和6 000 mg/L,pH为3,经过2 h反应,COD可降低至1 050 mg/L,去除率为97%。搅拌会降低COD的去除率。研究表明,UV/Fenton技术对高浓度乳化油废水具有很好的降解效果,且药品消耗较低,为目前此类高浓度有机废水的处理提供了技术参考。     

造纸中段废水的混凝-臭氧氧化深度处理研究

就混凝-臭氧氧化组合工艺对造纸中段废水生物处理出水的净化效果进行了研究.结果表明,Ca(OH)2对废水色度、TOC、COD和254 nm的紫外吸收值(UV254)的去除效果均优于聚合氯化铝/聚丙烯酰胺(PAC/PAM);Ca(OH)2-O3组合工艺的处理效果也优于PAC/PAM-O3工艺.当Ca(OH)2投加量为1 g/L、臭氧投加量为50 mg/L时,废水色度降低至10倍以下,COD小于150 mg/L.经Ca(OH)2混凝处理后,相对分子量在0.5～1.0 ku和10.0 ku以上的有机物显著减少;进一步臭氧氧化处理后,除0.5 ～1.0 ku范围的有机物大幅度增加外,其余分子量有机物显著减少.由于对色度贡献很大的大分子量物质的去除,废水的色度显著下降直至无色.     

Fenton氧化法深度处理纤维素乙醇废水

采用Fenton氧化法深度处理经生化降解后的纤维素乙醇废水,考察了初始pH值、Fe~(2+)与H_2O_2的投加比例(物质的量之比)、H_2O_2投加量与COD的比例(质量之比)以及反应时间对COD和浊度去除的影响,并通过正交实验确定了反应的最佳条件。研究表明:初始pH值、Fe~(2+)/H_2O_2、H_2O_2/COD以及反应时间对深度处理效果有不同程度的影响;在初始pH值为3.0、Fe~(2+)/H_2O_2为2∶3、H_2O_2/COD为2.8、反应时间为3 h的最佳反应条件下,出水COD为45~56 mg·L~(-1),浊度为2~3 NTU,达到了纤维素乙醇废水的排放标准。     

内循环（IC）厌氧反应器处理糖蜜酒精废水的研究

糖蜜酒精废水由于含有高浓度的COD和硫酸盐,一般厌氧反应器无法有效处理.研究了IC反应器处理糖蜜酒精废水的效果.考察其COD及硫酸盐的去除率、沼气的产量和组分等.结果表明,反应器对于COD为5000～10 000 mg/L的中、高浓度废水去除效果良好,当COD在20 000～30 000 mg/L时,在适应了1～2个停留时间后,去除效果达到稳定,去除率在90%左右.实验中最高容积负荷提升至40 kg COD/m3·d左右.本研究中所用的糖蜜酒精废水的COD/SO24-的平均值为61.9,未对反应器的处理效果及产气量产生影响.     

微涡旋絮凝-逆流气浮-纳滤集成工艺去除水中腐殖酸的动态运行特征

通过微涡旋絮凝逆流气浮-纳滤集成工艺的动态试验研究,确定其运行周期为72 h,能很好地去除水中腐殖酸有机物,但不同纳滤膜组成的集成工艺处理效果不同.采用PACl絮凝剂处理水样2时,以流程1运行的含TQ56-36FC型纳滤膜的集成工艺出水的高锰酸盐指数为0.45 mg/L,UV254nm在0.003 3左右波动,且有95%以上的脱盐率.以流程2运行的含M-N1812A型纳滤膜的集成工艺处理3种水样时的膜清水的高锰酸盐指数在0.75 mg/L左右波动,UV254nm大都远小于0.007 5,有时甚至为0.水样1和水样3的UV254nm平均值为0.005 4,水样2的最低,平均值为0.003 3,脱盐率只有6%～10%.以PACl为絮凝剂时,集成系统有较强的适应原水水质变化的能力.预处理中活性炭柱的存在提高了M-N1812A型纳滤膜清水样的水质,但并没有延长膜的使用周期.这也表明膜的污染更重要的是来自无机物的污染.     

污水土壤含水层处理系统原理、管理、效率和应用

论述了污水土壤含水层处理系统中的地球化学过程.该系统通过对污染物的机械过滤、生物化学转化和降解过程、吸附/解吸过程、氧化/还原过程、沉淀/溶解过程、以及矿物的合成过程净化污水.运作周期通常为1～2 d灌水/4～5 d排干,年水力负荷变化于15～100 m之间,应根据季节变化调整水力负荷.该系统能有效去除污水中的微生物和悬浮物,降低COD和BOD含量,和去除潜在的有毒的无机成分,如重金属和含氧阴离子.作为一种低投资、低能耗、高净化效率、运行简单的自然的污水处理技术,其在世界各国得到了广泛应用.我国部分地区水资源极其短缺,在土壤和气候条件适合的地区,应用土壤含水层处理技术处理污水,实现污水资源化,既解决了污水污染环境问题,又将在一定程度上缓解该地区的水资源短缺问题,对于经济与环境的协调发展具有重要意义.     

微絮凝-直接过滤工艺在城市污水深度处理中的应用研究

微絮凝 -直接过滤工艺是一种将混凝反应、沉淀截留集中在同一滤柱内同步完成的高效水处理工艺。该工艺应用于城市污水的深度处理中 ,通过絮凝剂的加入 ,具有同步去除PO3 -4 P、SS和部分COD的功能。本文研究了该工艺对二级处理出水中PO3 -4 P、SS和COD的去除效果及其规律。研究表明 :采用聚合氯化铁 (PFC)作为絮凝剂 ,当Fe/P摩尔比为 2∶1时 ,水中PO3 -4 P的去除率达 98.8% ,浓度可降至 0 .1mg/L以下 ,同时SS、COD去除率也有明显提高。与传统的混凝、沉淀除磷工艺相比 ,该工艺具有操作简单、结构紧凑、占地面积小、污泥量少等优点 ,是一种更为经济和简单的处理单元 ,适用于现有城市污水处理厂的除磷和进一步提高水质的深度处理     

垃圾填埋场渗滤液物化深度处理研究

通过Fenton法和结合聚合硫酸铁的混凝作用，实现垃圾渗滤液氧化塘出水COD的深度处理；并利用水泥水化产物的凝胶物质，强化COD去除率。30％H2O2投加量为0．75mL／L、七水硫酸亚铁投加量为1．5g／L、n（H2O2）：n（Fe^2＋）=1．2：1（摩尔比）时，Fenton法对渗滤液COD的去除率可达52％；水灰比为2：1、搅拌24h的水泥水化物将Fenton法的出水pH值从4调至10，该工艺流程总的COD去除率为73．6％，较普通的Ca（OH）2调节法提高9．3％，出水COD可以从进水的1200mg／L降至315mg／L。     

Analysis of chemical compositions contributable to chemical oxygen demand (COD) of oilfield produced water

This work was to give a comprehensive estimation for the chemical compositions contributable to COD of the produced water treatment system. For this purpose, the wastewater samples were collected from an onshore wastewater treatment plant. The chemical compositions of the wastewater were investigated, and the COD contributed by each component was estimated. The results showed that the COD levels of O&G and SS presented decreasing trends during the whole process and achieved total removal percentages of 95.1% and 62.3%, respectively. The final COD of organic acids and low-molecular-weight carbonyl compounds were respectively lowered to nearly 64% and 35% of their initial levels, and no regular trends were found for the COD of these chemicals during the whole treatment process. The COD of inorganic components presented minor variations at all sampling spots. The majority of COD was originated from O&G in raw wastewater. The COD contributed by O&G decreased greatly with continuous treatment and finally was lower than 17% of measured COD. At each sampling spot, the ratios of COD contributed by SS did not exceed 7.6% of measured COD. Other measured chemicals, including organic acids, carbonyl compounds, volatile phenols, reductive anions, metals and TDP were not the main sources of COD during the whole treatment process, and the ratio of COD was below 9% at each sampling spot. Most of the soluble components contributable to residual COD were still unknown after biological treatment, and the COD contributed by these components was greater than 57% of measured COD.     

Treatment of distillery spent-wash by ozonation and biodegradation: significance of pH reduction and inorganic carbon removal before ozonation.

This study is aimed at exploring strategies for mineralization of refractory compounds in distillery effluent by anaerobic biodegradation/ozonation/aerobic biodegradation. Treatment of distillery spent-wash used in this research by anaerobic-aerobic biodegradation resulted in overall COD removal of 70.8%. Ozonation of the anaerobically treated distillery spent-wash was carried out as-is (phase I experiments) and after pH reduction and removal of inorganic carbon (phase II experiments). Introduction of the ozonation step resulted in an increase in overall chemical oxygen demand (COD) removal, with the highest COD removals of greater than 95% obtained when an ozone dose of approximately 5.3 mg ozone absorbed/mg initial total organic carbon was used. The COD removal during phase II experiments was slightly superior compared with phase I experiments at similar ozone doses. Moreover, efficiency of ozone absorption from the gas phase into distillery spent-wash aliquots was considerably enhanced during phase II experiments.     

Chemical oxygen demand reduction of various wastewater types using magnetic field-assisted fenton reaction.

Constant magnetic field (CMF) was investigated for its potential to intensify chemical oxygen demand (COD) removal in wastewater when applied with a generalized Fenton reaction. Various types of industrial and domestic wastewater were tested in the experiment. A significant dependence was observed between the wastewater type, dose of reacting substances, time of exposure to CMF, effectiveness of COD removal, and the rate of the advanced oxidation process. The use of CMF resulted in the improvement of the treatment process; however, the efficiency depended to a great extent on the type of wastewater and characteristics of the contained organic matter. Domestic wastewater seemed to be most amenable to the applied treatment (82% COD reduction). The least reduction in COD occurred for wood industry wastewater. In the analyzed wastewater, intense oxidation was observed during the first 60 minutes of the process. Longer reaction time did not increase COD reduction, with the exception of wood industry wastewater. The experiment revealed the possibility of applying smaller doses of the Fenton's reagent, thereby keeping up unchanged treatment efficiency, provided that CMFs are applied.     

Anaerobic treatment of atrazine bearing wastewater.

Performance of mixed microbial anaerobic culture in treating synthetic waste-water with high Chemical Oxygen Demand (COD) and varying atrazine concentration was studied. Performance of hybrid reactors with wood charcoal as adsorbent, with a dose of 10 g/l and 40 g/l, along with the microbial mass was also studied. All the reactors were operated in sequential mode with Hydraulic Retention Time (HRT) of 5 days. In all the cases, COD removal after 5 days was found to be above 81%. Initial COD was above 1,000 mg/l. From a hybrid reactor COD removal after 2 days was observed to be 90%. Atrazine reduction after 5 days by microbial mass alone was 43.8%, 40% and 33.2% with an initial concentration of 0.5, 1.0 and 2.0 mg/l respectively. MLSS on all the cases were almost same. Increasing MLSS concentration by about 2 fold did not increase the atrazine removal efficiency significantly. Maximum atrazine removal was observed to be 64% from the hybrid reactor with 10 g/l of wood charcoal and 69.4% from the reactor with 40 g/l of wood charcoal. Atrazine removal from the hybrid reactors after 15 days were observed to be 35.7% and 38.7%, which showed that the higher dose of wood charcoal in hybrid reactor did not improve the atrazine removal efficiency significantly. Specific methanogenic activity test showed no inhibitory effect of atrazine on methane producing bacteria. The performance of anaerobic microorganisms in removing atrazine with no external carbon source and inorganic nitrogen source was studied in batch mode. With an initial concentration of 1.0 mg/l, reduction of atrazine by the anaerobic microorganisms in absence of external carbon source after 35 days was observed to be 61.8% where as in absence of external carbon and inorganic nitrogen source the reduction was only 44.2% after 150 days. Volatilization loss of atrazine was observed to be insignificant.     

ANAEROBIC TREATMENT OF ATRAZINE BEARING WASTEWATER

Performance of mixed microbial anaerobic culture in treating synthetic wastewater with high Chemical Oxygen Demand (COD) and varying atrazine concentration was studied. Performance of hybrid reactors with wood charcoal as adsorbent, with a dose of 10 g/l and 40 g/l, along with the microbial mass was also studied. All the reactors were operated in sequential mode with Hydraulic Retention Time (HRT) of 5 days. In all the cases, COD removal after 5 days was found to be above 81%. Initial COD was above 1000 mg/l. From a hybrid reactor COD removal after 2 days was observed to be 90%. Atrazine reduction after 5 days by microbial mass alone was 43.8%, 40% and 33.2% with an initial concentration of 0.5, 1.0 and 2.0 mg/l respectively. MLSS on all the cases were almost same. Increasing MLSS concentration by about 2 fold did not increase the atrazine removal efficiency significantly. Maximum atrazine removal was observed to be 64% from the hybrid reactor with 10 g/l of wood charcoal and 69.4% from the reactor with 40 g/l of wood charcoal. Atrazine removal from the hybrid reactors after 15 days were observed to be 35.7% and 38.7%, which showed that the higher dose of wood charcoal in hybrid reactor did not improve the atrazine removal efficiency significantly. Specific methanogenic activity test showed no inhibitory effect of atrazine on methane producing bacteria. The performance of anaerobic microorganisms in removing atrazine with no external carbon source and inorganic nitrogen source was studied in batch mode. With an initial concentration of 1.0 mg/l, reduction of atrazine by the anaerobic microorganisms in absence of external carbon source after 35 days was observed to be 61.8% where as in absence of external carbon and inorganic nitrogen source the reduction was only 44.2% after 150 days. Volatilization loss of atrazine was observed to be insignificant.     

Organic-coated nanoparticulate zero valent iron for remediation of chemical oxygen demand (COD) and dissolved metals from tropical landfill leachate

The use of nanoparticulate zero valent iron (NZVI) in the treatment of inorganic contaminants in landfill leachate and polluted plumes has been the subject of many studies, especially in temperate, developed countries. However, NZVI’s potential for reduction of chemical oxygen demand (COD) and treatment of metal ion mixtures has not been explored in detail. We investigated the efficiency of NZVI synthesized in the presence of starch, mercaptoacetic, mercaptosuccinic, or mercaptopropenoic acid for the reduction of COD, nutrients, and metal ions from landfill leachate in tropical Sri Lanka. Synthesized NZVI were characterized with X-ray diffraction (XRD), transmission electron microscopy, X-ray photoelectron spectroscopy, scanning electron microscopy (SEM), thermal gravimetric analysis, Fourier transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller. Of the samples tested, Starch-NZVI (S-NZVI) and mercaptoacetic-NZVI (MA-NZVI) performed well for treatment both COD and metal mixture. The removal percentages for COD, nitrate-nitrogen, and phosphate from S-NZVI were 50, 88, and 99 %, respectively. Heavy metal removal was higher in S-NZVI (>95 %) than others. MA-NZVI, its oxidation products, and functional groups of its coating showed the maximum removal amounts for both Cu (56.27 mg g^?1) and Zn (28.38 mg g^?1). All mercapto-NZVI showed well-stabilized nature under FTIR and XRD investigations. Therefore, we suggest mercapto acids as better agents to enhance the air stability for NZVI since chemically bonded thiol and carbonyl groups actively participation for stabilization process.