Changes in the quality of river water before, during and after a major flood event associated with a La Niña cycle and treatment for drinking purposes

The treatment of organics present in the lower reaches of a major river system（the Murray–Darling Basin, Australia） before（March–July 2010）, during（December 2010–May 2011） and after（April–December 2012） a major flood period was investigated. The flood period（over 6 months）occurred during an intense La Nia cycle, leading to rapid and high increases in river flows and organic loads in the river water. Dissolved organic carbon（DOC） increased（2–3 times） to high concentrations（up to 16 mg/L） and was found to correlate with river flow rates. The treatability of organics was studied using conventional jar tests with alum and an enhanced coagulation model（mEnCo）. Predicted mean alum dose rates（per mg DOC） were higher before（9.1 mg alum/mg DOC） and after（8.5 mg alum/mg DOC） than during the flood event（8.0 mg alum/mg DOC）,indicating differences in the character of the organics in raw waters. To assess the character of natural organic matter present in raw and treated waters, high performance size exclusion chromatography with UV and fluorescence detectors were used. During the flood period, high molecular weight UV absorbing compounds（〉2 kDa） were mostly detected in waters collected,but were not evident in waters collected before and afterwards. The relative abundances of humic-like and protein-like compounds during and following the flood period were also investigated and found to be of a higher molecular weight during the flood period. The treatability of the organics was found to vary over the three climate conditions investigated.     

冷轧废水处理的试验研究

采用混凝－ＳＢＲ生化－砂滤工艺，以超滤处理后的冷轧废水进行了处理。结果表明，ＣＯＤｃｒ为５９０￣１０００ｍｇ／Ｌ的冷轧超滤废水经该工艺处理后，ＣＯＤｃｒ和ＢＯＤ５的平均去除率分别为８２．５％和９４．３％，出水达到国家排放标准。     

印染废水处理方法的研究

针对印染废水的特点 ,采用混凝沉降 -氧化法处理印染废水。根据生产实际 ,把废水分成较易处理和较难处理两种情况。经过混凝沉降、化学氧化、砂滤后 ,可达到国家印染废水的排放标准。同时 ,确定了主要技术参数和工艺流程 ,并对实验结果进行了理论和经济分析     

城市污水处理过程中有机物迁移转化的研究(甲苯)

讨论了城市污水分别经过混凝沉降和A／O工艺处理时，污水中有机物的迁移和转化。所采用的方法是将原水、处理后的出水及污泥用甲苯萃取，萃取相经过真空浓缩后，采用GC／MS测定了样品中的有机化合物，对两种处理过程中有机物的迁移转化后进行了对比。结果表明，在A／O工艺处理城市污水过程中，吸附作用是主要的，降解作用是次要的。     

直接超滤和混凝-超滤组合工艺的膜污染比较

利用滤饼层过滤模型和膜孔窄化模型，结合国产中空纤维超滤膜对提取的天然腐植酸进行直接超滤和混凝－超滤2种工艺的试验结果分析，表明混凝预处理基本消除了膜孔污染，并且大大降低了膜表面滤饼层污染阻力，从而使超滤保持高渗透通量。另外，与原水直接超滤相比，混凝－超滤组合工艺对溶解性天然有机物的去除率较高，DOC去除率从28％提高到53％，UV254去除率从40％提高到78％。     

炼油废水高效处理的工艺流程和操作方法

本文论述了采用组合式隔油与两级混凝气浮串联工艺处理某炼油厂的含油废水的运行情况。由于各个处理单元及整套工艺的设计合理、操作方法正确 ,该套废水处理系统出水中的油类浓度降至 5～ 8m g/ L,COD浓度降至 45～ 5 5 mg/ L ,SS降至 3 1～ 5 1mg/ L,去除率分别超过 98%、92 %与 83 %。工程实施两年多来 ,运行稳定 ,能回收油类 ,具有良好的经济效益。     

Removal of emulsified fuel oils from brackish and pond water by dissolved air flotation with and without polyelectrolyte use: pilot-scale investigation for estuarine and near shore applications

In coastal areas, estuaries, and inland waters, dispersant use after oil spills is not allowed due to sensitivity of the ecosystems. The purpose of this study was to investigate the removal of emulsified fuel oils from brackish and pond water by dissolved air flotation (DAF) with and without use of coagulants. Experiments were conducted with a 60 L DAF system. Fuel oil-water emulsions were prepared with regular unleaded gasoline, jet fuel, and diesel fuel mixed at 1:1:1 (v/v/v) ratio. Batch and continuous runs were conducted at air pressurization of 354.6 kPa. During both batch and continuous modes, significant petroleum hydrocarbon (PHC) removal was achieved within 10 min. Coagulant addition initially increased the PHC removal by about 5-15%. However, effectiveness of the coagulant was not significant after 20 min due to breakage of the aggregates. In general, the pond water had higher PHC removal than the brackish water. With longer run times, PHC removal improved slightly and the effluent contained increasing fractions of higher molecular weight compounds indicating that PHC removal was due to both DAF and stripping processes. Results indicate that DAF process can be effective both with and without the use of coagulants for removing PHCs from brackish and pond waters.     

A novel application of H2O2-Fe(II) process for arsenate removal from synthetic acid mine drainage (AMD) water

Batch experiments were carried out to investigate the influences of H₂O₂/Fe(II) molar ratio, pH, sequence of pH adjustment, initial As(V) concentration, and interfering ions on As(V) removal in H₂O₂-Fe(II) process from synthetic acid mine drainage (AMD). The optimum H₂O₂/Fe(II) molar ratio was one for arsenate removal over the pH range of 4-7. Arsenate removal at pH 3 was poor even at high Fe(II) dosage due to the high solubility of Fe(III) formed in situ. With the increase of Fe(II) dosage, arsenate removal increased progressively before a plateau was reached at pH 5 as arsenate concentration varied from 0.05 to 2.0 mg L⁻¹. However, arsenate removal was negligible at Fe/As molar ratio <3 and then experienced a striking increase before a plateau was reached at pH 7 and arsenate concentration ≥1.0 mg L⁻¹. The co-occurring ions exerted no significant effect on arsenate removal at pH 5. The experimental results with synthetic AMD revealed that this method is highly selective for arsenate removal and the co-occurring ions either improved arsenate removal or slightly depressed arsenate removal at pH 5-7. The extended X-ray absorption fine structure (EXAFS) derived As-Fe length, 3.27-3.30 Å, indicated that arsenate was removed by forming bidentate-binuclear complexes with FeO(OH) octahydra. The economic analysis revealed that the cost of the H₂O₂-Fe(II) process was only 17-32% of that of conventional Fe(III) coagulation process to achieve arsenate concentration below 10 μg L⁻¹ in treated solution. The results suggested that the H₂O₂-Fe(II) process is an efficient, economical, selective and practical method for arsenate removal from AMD.     

Surface water treatment benefits from the presence of algae: Influence of algae on the coagulation behavior of polytitanium chloride

• Emerging titanium coagulation was high-efficient for algae-laden water treatment. • Polytitanium coagulation was capable for both algae and organic matter removal. • Surface water purification was improved by around 30% due to algae inclusion. • Algae functioned as flocculant aid to assist polytitanium coagulation. • Algae could enhance charge neutralization capability of polytitanium coagulant. Titanium-based coagulation has proved to be effective for algae-laden micro-polluted water purification processes. However, the influence of algae inclusion in surface water treatment by titanium coagulation is barely reported. This study reports the influence of both Microcystis aeruginosa and Microcystis wesenbergii in surface water during polytitanium coagulation. Jar tests were performed to evaluate coagulation performance using both algae-free (controlled) and algae-laden water samples, and floc properties were studied using a laser diffraction particle size analyzer for online monitoring. Results show that polytitanium coagulation can be highly effective in algae separation, removing up to 98% from surface water. Additionally, the presence of algae enhanced organic matter removal by up to 30% compared to controlled water containing only organic matter. Polytitanium coagulation achieved significant removal of fluorescent organic materials and organic matter with a wide range of molecular weight distribution (693–4945 Da) even in the presence of algae species in surface water. The presence of algae cells and/or algal organic matter is likely to function as an additional coagulant or flocculation aid, assisting polytitanium coagulation through adsorption and bridging effects. Although the dominant coagulation mechanisms with polytitanium coagulant were influenced by the coagulant dosage and initial solution pH, algae species in surface water could enhance the charge neutralization capability of the polytitanium coagulant. Algae-rich flocs were also more prone to breakage with strength factors approximately 10% lower than those of algae-free flocs. Loose structure of the flocs will require careful handling of the flocs during coagulation-sedimentation-filtration processes.     

电絮凝法处理油田污水

应用电絮凝浮选法对油田３类主要污水进行处理研究证实:炼油厂含油污染水含油量去除率达９６％,ＳＳ去除率达９７％;钻井污水浊度去除率达９６.８％,ＣＯＤ去除率达９７.５％;采油污水浊度去除率达９６.１％,含油量去除率达１００％。以上各项指标均远低于国家综合污水排放标准。电絮凝浮洗法不但处理油田污水效果显著,而且设备简单,耐冲击性、操作简单、不需投加化学药剂、增设投药设备和易实现管理现代化等优点,为油田污水处理提供了一条新途径