石材加工业废水处理浅谈

介绍了石材加工业废水处理的常用方法,论述了用絮凝沉淀法处理石材废水的工艺要点。     

絮凝沉淀-A/O工艺处理印染废水

采用絮凝沉淀－A／O工艺,对郑州市古荥印染厂的废水进行了治理,处理后,废水达到GB4287－92二级标准,且投资少,效果好。证明该工艺是一种行之有效的处理方法。     

含磷废水处理的工艺设计与成本分析

含磷废水含单质磷,易燃且毒性强,如不经处理直接排放,将对环境造成严重危害。对于含磷废水的处理,在我国一般采用物化法,典型的工艺有沉淀氧化法和废水闭路循环处理法,本文采用次氯酸钙氧化+化学混凝沉淀的方法对废水进行处理。同时结合工程实例,简要介绍了含磷废水处理的工艺流程、主要设备、运行效果、成本分析和注意事项等,以期此套工艺在行业内得到推广和应用。     

酸性重金属废水处理工艺

本污水处理系统处理对象为酸性重金属废水,采用"中和反应+铁盐沉淀+吸附反应+絮凝沉淀"工艺,处理效果好且具有较强适应性,可满足水质、水量的变化。     

螯合沉淀法处理含铬电镀废水

以NaHSO3为还原剂,新型重金属离子捕集剂DTCR为螯合剂,采用螯合沉淀法处理含铬电镀废水。研究了还原剂投加量、还原反应阶段的废水pH、螯合剂投加量、絮凝剂(PAM)投加量、螯合沉淀阶段的废水pH和搅拌时间对处理效果的影响。还原反应的较优工艺为:NaHSO3200mg/L,废水pH1.84,搅拌时间30min。螯合沉淀的最佳工艺条件为:DTCR70mg/L,PAM8mg/L,废水pH8.0,搅拌时间40min。采用最佳螯合沉淀工艺处理含铬电镀废水时,总铬去除率在95%以上,出水总铬为0.14mg/L,且未检测到其他重金属离子,可达标排放。     

乳化液废水处理工程的设计实例

对天津钢管公司管加工厂排放的乳化液废水和磷化锌废水的原有处理工艺进行了改造，采用隔油－破乳－气浮－混凝沉淀－过滤等工艺处理后，可达标排放，且对纯乳化液废水也能单独处理。     

石灰-硫酸-铁盐法处理含氟废水的试验研究

本文介绍的石灰-硫酸-铁盐综合处理含氟废水的工艺是一种较为简单、实用的处理工艺。它的基本原理是借助石灰、铁盐沉淀、络合、吸附氟离子的功能,去除废水中的氟化物,并加入硫酸生成硫酸钙沉淀。净化后的废水基本上达到国家排放标准,产生的废渣可以综合利用。此工艺操作方便、运转费用低,且无二次污染产生。     

再生造纸废水低成本治理工艺优化及应用

通过对国内外再生造纸废水处理工艺的归纳与总结,结合再生造纸的工艺特点,提出再生造纸废水低成本治理工艺。采用锅炉烟气处理脱墨黑夜,漂白废水用于废水脱色,采用絮凝沉淀、过滤等物化＋生化处理相结合的方法处理综合废水。     

铁炭微电解-混凝沉淀预处理密度纤维板热磨废水

研究了铁炭微电解-混凝沉淀对于密度纤维板热磨废水的预处理效果。通过试验,得出处理该废水的组合工艺最佳条件为:调节废水初始pH值为3.0,进行铁炭微电解反应60min,然后调节pH值为8.5,进行混凝沉淀60min。在进水COD的质量浓度为5183mg/L,色度为500倍时,经组合工艺处理后,COD去除率可达92%以上,脱色率达99%以上,且出水生化性好。     

AAOO-Fenton氧化工艺处理焦化废水

介绍了焦化废水的特点以及AAOO-Fenton氧化工艺处理济钢焦化废水的运行效果。蒸氨废水经AAOO工艺处理后,再经过高效混凝沉淀及Fenton氧化深度处理,出水水质达到了国家二级排放标准。     

硫酸盐有机废水厌氧处理颗粒污泥研究进展

厌氧工艺是硫酸盐有机废水处理中最具竞争力的技术,厌氧颗粒污泥则是其核心,开展该类废水厌氧处理颗粒污泥特性的研究,对提高其厌氧处理效率具有重要意义。本文综述了硫酸盐有机废水厌氧处理颗粒污泥近年来的国内外研究进展,主要包括颗粒污泥的理化特性（形态及粒径、孔隙、通道及沉降速度、胞外沉积物等）及颗粒污泥的生物学特性（生物活性、微生物形态、组成及分布）,并分析了此方面研究工作存在的问题,认为硫酸盐有机废水厌氧处理颗粒污泥活性抑制机理的研究以及从本质上解除这种抑制措施的提出,将是今后需要重点关注的研究内容。     

Removal of Arsenic from Wastewaters by Airlift Electrocoagulation: Part 3: Copper Smelter Wastewater Treatment

The arsenic content in wastewater is of major concern for copper smelters. A typical complex wastewater treatment is needed with a combination of chemical and physical processes. Electrocoagulation (EC) has shown its potential for arsenic removal due to the formation of ferric hydroxide-arsenate precipitates. This work evaluates the feasibility of EC as a treatment process at various stages during conventional copper smelter wastewater treatment – with a focus on arsenic. The reactor used is a batch airlift electrocoagulator. The results showed that raw copper smelter wastewater was difficult to treat for arsenic and heavy metals with EC, mainly due to the very low pH. On the other hand, after a preliminary Ca(OH)₂ treatment for sulphate and heavy metal removal, arsenic could be removed totally by EC. In addition, EC could also be applied as a final remediation control tool for arsenic since the national threshold value for wastewater discharge could rapidly be reached when the conventional method did not clean the wastewater sufficiently.     

KMnO_4/FeSO_4强化混凝处理石材加工废水

以平顶山某石材加工厂排放的废水为研究对象,对比研究了传统混凝剂与KMnO_4/FeSO_4协同强化混凝的处理效果。结果表明,利用KMnO_4/FeSO_4协同强化混凝处理该废水,在最佳条件下,处理后废水浊度为6 NTU,浊度去除率达到99%,浑液面沉速可达1.55 cm/min,处理出水水质及沉淀效率均高于传统的混凝药剂。KMnO_4/FeSO_4协同强化混凝技术能快速有效地处理高浊度废水。     

Mechanisms of formation of iron precipitates from ferrous solutions at high and low pH

The oxidation and subsequent precipitation of iron from solutions are very important for most hydrometallurgical wastewater treatment practitioners. The particle formation process mechanisms are important for shaping the dewaterability and particle size distribution of the precipitates. In this study the objective is to elucidate the mechanisms of iron particles formation from ferrous solutions at high (pH 9.0) and low pH (pH 6.0). The results obtained showed that the precipitation process is dominated by nucleation at the initial stages and aggregation dominated at the final stages. The precipitates formed at higher pH transform faster and result in the formation of more stable precipitates. Precipitates formed at pH 6.0 are larger but less stable chemically. The results may mean higher throughputs and lower costs of post precipitation stabilisation for operations at higher pH. The benefits for operation at lower pH would be a better solid-liquid separation due to the bigger sized particles formed.     

TREATMENT OF KRAFT PULP AND PAPER WASTEWATERS BY MEANS OF FOAM SEPARATION

The pulp and paper industry is the third largest industrial consumer of fresh water in the United States. The current use rate of over two trillion gallons annually is expected to increase as the demand for paper products continues to rise

Of the various methods of producing paper from wood, the Kraft process is the most widely used. Color, dissolved and suspended organic matter, and dissolved inorganic solids are major pollutants in Kraft processing wastewater. Current federal regulations limit the amount of solids and organic matter that a Kraft facility may dispose into public waters, so most plants have some form of wastewater treatment

In this study, the capacity of a continuous-flow, foam separation system to effect removals of color from a Kraft process wastewater was evaluated. The cationic surfactant, EHDABr, was used to precipitate color bodies in the wastewater and create a foam to carry the precipitates from the wastewater. The effect of pH adjustment was also considered. Color removals in the area of 90% were achieved

Removal of precipitated solids was enhanced by increasing the detention of wastewater in the treatment system.     

A study on nickel hydroxide crystallization characteristics

The precipitation characteristics of nickel hydroxide as well as carbonate and sulfide were studied to determine the proper treatment condition of the wastewater induced from nickel-plating industry. When the pH value was maintained higher than 10, the nickel concentrations in the effluent could be kept lower than 5 mg/l. The precipitation of nickel salts in the model wastewater was conducted by alkaline addition, such as the uses of sodium hydroxide, sodium carbonate, sodium bicarbonate and sodium sulfide. In case of sulfide treatment, the nickel concentration of treated wastewater showed the lowest value after the removal of precipitates. The change of particle size of the crystal precipitates by the precipitation conditions and precipitants was also investigated. In spite of the various precipitation conditions that were adopted, the change of particle size of the crystal precipitates showed no great differences. The settling rates of the precipitated particles were observed and the free settling period was terminated within 20 minutes. Although the hindered settling as well as bed compaction progressed subsequently, the bed heights were maintained almost the same level after few hours later     

改性淀粉/聚胺复合物在石材加工废水处理中的应用研究

研究了改性木薯淀粉和聚胺复合物在高浊度、高SS及高色度的石材加工废水中的絮凝性能.实验结果表明,复合物的用量为8 mg/L、沉降时间为30 min时,可使废水(pH=9)的主要污染指标达到国家污水排放二级标准,其处理成本分别是聚合氯化铝(PAC)、CPAM和聚胺的44%、36%和50%,对石材加工废水处理显示出优越的性价比.     

2-萘酚生产废水处理技术研究进展

2-萘酚是一种重要有机中间体,其传统的浓硫酸磺化-碱熔生产工艺产生的废水量大,水质成分复杂,并会有较高价值的中间产物。从2-萘酚生产工艺过程上分析了废水来源和废水特性,综述了氧化法、浓缩法、吸附法和组合工艺对2-萘酚生产废水的处理研究进展。指出改进生产工艺,从源头减少废水排放,以及利用工厂自身的余热、余料开发低成本组合工艺实现废水处理与资源化应是以后2-萘酚生产废水处理的研究方向。     

火力发电厂烟气脱硫废水处理

湿法脱硫工艺是现阶段全世界范围内应用最为广泛的烟气脱硫工艺,在湿法脱硫工艺中,不可避免的要产生一定量的废水。文章结合烟气脱硫废水的水质特征,简要综述了烟气脱硫废水处理工艺中中和、沉淀、混凝以及污泥脱水等各步骤的处理方法和研究进展等,并指出了现阶段我国在烟气脱硫废水处理研究和设计中存在的一些不足。     

天然有机吸附剂在重金属废水处理中的应用

在介绍传统重金属废水处理方法及其优缺点的基础上,阐述了吸附工艺对重金属废水处理的优势,综述了壳聚糖、纤维素、腐殖酸、细菌、真菌和藻类等典型天然有机吸附材料在重金属废水处理中的应用,并对天然有机吸附材料处理重金属废水的发展趋势进行了展望。