混凝法深度处理废纸造纸废水实验研究

按照烧杯实验方法,重点考察了pH值、混凝剂种类和投加量等因素对生化处理后废纸造纸废水混凝处理效果的影响。实验结果表明:PAC作为混凝剂,PAM作为助凝剂联合处理该废水时,能够取得较好的去浊率、SS、色度和COD去除率。混凝沉淀最佳运行条件为:废水pH为6.5,含铝量10%的PAC和2 g/L的PAM投加量分别为1 mL/L、0.5 mL/L,浊度从35 NTU降低到1 NTU,去除率达97.1%,SS从30 mg/L降低到7 mg/L,去除率达76.7%,色度从64倍降低到18倍,去除率达71.9%,COD从95 mg/L降低到44.8 mg/L,去除率可达52.8%,取得了较好的去除效果,达到国家造纸废水新排放标准限值。     

不同铝系混凝剂处理印染废水

印染废水具有色度大、有机物含量高、水质变化大等特点,处理难度较大。对比了不同种类的混凝剂对印染废水的处理效果,结果表明,随着混凝剂投加量的增加,SS,色度和COD的去除率逐渐增大,当混凝剂的投加量达到80 mg/L时,4种混凝剂的混凝效果达到最优。Al_(13)在最优投加量下SS的去除率达到92.47%,色度去除率达到88.49%,COD的去除率达到80.47%。不同p H值条件下的混凝实验结果表明,随着p H值的升高,混凝效果逐渐提高,在p H值处于6.0~9.0的范围内均具有良好的混凝效果。在沉降的初始阶段,随着沉降时间的延长,4种混凝剂的混凝效果逐渐提高;当沉降时间超过10 min后,混凝效果没有明显的提高。Al_(13)形成絮体的沉降速度最快,11 min左右可以完成沉降,其他3种混凝剂需要在14 min左右完成沉降。     

强化混凝预处理削减中药废水的毒性

采用混凝法对毒性强,COD、SS浓度高,色度大的中药废水进行预处理。首先,通过对比研究聚合硫酸铁(PFS)、聚合氯化铝(PAC)、硫酸铝(AS)、硫酸亚铁(Fe SO4·7H2O)对中药废水急性毒性和对COD、SS的去除效果,确定投加方案为PFS(500 mg·L~(-1));其次研究了pH值、助凝剂聚丙烯酰胺(PAM)和壳聚糖(CTS)对PFS混凝效果的影响,并确定了最佳混凝参数。研究结果表明:当初始pH为7.0时,500 mg·L~(-1)PFS与8.0 mg·L~(-1)PAM配合使用对中药废水具有最佳混凝效果,COD、SS去除率分别达到38.6%、98.9%,急性毒性由EC50=8.12%的降低至EC50=41.35%,毒性级别由极强削弱至中等。     

玉米深加工废水的混凝实验

在室温条件下,分别选用聚合氯化铝(PAC)、聚合氯化铝铁(PAFC)及三氯化铁(FeCl3)对玉米深加工废水进行混凝实验。综合考虑各种混凝剂对磷、COD以及SS的去除效果,最终选取PAC作为混凝剂。采用PAC和聚丙烯酰胺(PAM)作为复合混凝剂,对其去除效果做进一步研究,并确定了最佳投加量及pH值。实验结果表明,在PAC投加量25mg/L,PAM投加量0.5 mg/L,pH为8条件下,混凝效果最佳。磷、COD、SS去除率可分别达到90.1%、53.3%和88.2%,对应的出水质量浓度分别为0.41、26.8和2 mg/L。     

制革废水试验研究

采用预处理-混凝沉淀-微滤组合工艺对制革废水进行试验研究.结果表明,制革废水经预处理后用硫酸亚铁酸洗废液作混凝剂是行之有效的,经此工艺处理后,COD、BOD5、SS和色度去除率分别为80.4%、87.2%、88.6%和91.7%,处理后废水水质达到排放标准且可回用于生产.在较低温度下,用硫酸亚铁作混凝剂仍能较好地完成混凝沉淀,验证了硫酸亚铁的低温混凝效果.此工艺具有很好的应用前景,尤其适合北方寒冷地区.     

干法腈纶废水混凝处理研究

针对干法腈纶废水的特点及目前混凝剂产品使用现状,采用无机混凝剂单一与无机/有机混凝剂复配进行混凝实验,确定最佳混凝剂和最佳混凝条件.结果表明:(1)单一无机混凝剂处理干法腈纶废水时,聚合硫酸铁(PFS)的混凝效果要好于其他无机混凝剂.当废水pH为11.03、PFS用量为700 mg/L时,COD去除率达到20.89%,较现有干法腈纶生产厂家普遍采用的混凝处理方法提高了7.89%～10.89%.(2)PFS与聚丙烯酰胺(PAM)复配的混凝效果明显比单一PFS好;PFS与阳离子型PAM复配的混凝效果最好,其最佳用量分别为400、7 mg/L,COD由1 700.00 mg/L降到1 331.44 mg/L,去除率达到21.68%,较现有干法腈纶生产厂家普遍采用的混凝处理方法提高了8.68%～11.68%.     

皮革含铬废水加碱处理研究

用加碱沉淀法处理制革铬鞣废水时 ,MgO CaO(1∶4 ,w∶w)取得较好的处理效果 ,其机理包括调节pH与混凝沉淀。铬鞣废水Cr3+ 和色度去除率大于 99% ,SS去除率大于 87% ,但COD去除率只有 4 7% ,主要依靠协同沉降。混合废水处理效果也很好 ,但铬泥沉降较差。有机杂质的存在较大地影响了Cr3+ 的去除 ,一定量的SS有利于铬泥的沉降。     

新型氧化-混凝剂处理染料废水研究

根据染料废水的特点 ,研究了自制产品新型氧化 混凝剂处理染料废水的情况 ,探索了药剂用量、pH值等因素对COD、色度去除率的影响。试验表明 ,当pH >10、“染清”氧化 混凝剂的加入量万分之三左右、絮凝时间 6min、静置沉淀3 5min时 ,该药剂对染料废水具有良好的效果 ,COD和色度的去除率最高分别可达 97%和 86% ,从而证明该方法对于染料废水的处理是可行的。该处理工艺设备简单 ,系统运行稳定 ,操作方便 ,成本低     

皮革含铬废水加碱处理研究

用加碱沉淀法处理制革铬鞣废水时，MgO／CaO(1：4，w：w)取得较好的处理效果，其机理包括调节pH与混凝沉淀。铬辣废水Cr^3 和色度去除率大于99％，SS去除率大于87％，但COD去除率只有47％，主要依靠协同沉陷。混合废水处理效果也很好，但铬泥沉降较差。有机杂质的存在较大地影响了Cr^3 的去除，一定量的SS有利于铬泥的沉降。     

混凝-热处理联合MAP法处理高浓度水性油墨印花废水

采用混凝-热处理联合磷酸铵镁沉淀法(MAP)处理高浓度水性油墨印花废水,研究了各工艺参数对该废水处理效果的影响。研究表明:混凝-热处理可降低废水的COD和色度,实现固液快速分离,有效降低混凝污泥含水率;MAP法可有效降低混凝-热处理后废水的氨氮含量,药剂摩尔比和反应体系pH对氨氮去除效果影响较大。当投加15 m L·L~(-1)的40%(体积分数)混凝剂NS-1、在70℃下热处理50 min的条件下,废水的COD去除率达到93.65%,色度去除率达到99.97%,而混凝污泥含水率可降到56.62%;向混凝-热处理后废水中投加硫酸镁和磷酸氢二钠,当药剂摩尔比为1.1:0.9:1(Mg:P:N)、体系pH为9.5、在20℃反应30 min的条件下,废水的氨氮去除率可达96.27%,剩余总磷低于12 mg·L~(-1)。     

硼泥复合混凝剂处理印染废水的研究

采用自制的硼泥复合混凝剂对所选择的若干水溶性染料水样和实际印染废水进行脱色试验，结果表明，混凝效果与染料种类，投药量，ｐＨ值，温度等因素有关，其中投药量范围在０．３￣０．６ｇ／Ｌ，ｐＨ适用范围为４．０￣１１．５，脱色率均可达９２％以上，在处理实际印染废水样时，仅投加０．３ｇ／Ｌ混凝剂时，其ＣＯＤ去除率达６７％以上，脱色率和ＳＳ去除率均达９８％以上，ｐＨ值也处于６￣９范围之内，并且比聚铝的处理效果好     

聚硅硫酸铁混凝去除石化废水二级出水中有机污染物的研究

采用聚硅硫酸铁(PFSiS)混凝剂对石化废水二级出水进行了强化混凝实验,考察其对有机污染物的去除效果,并对不同时期的絮体微观结构进行了研究。结果表明,PFSiS可有效去除水中COD,当PFSiS投加量为40 mg/L(以Fe计),静置时间为120 min,COD去除率可达50%左右;絮体的微观结构为空间网状结构,随静置时间的延长,絮体密实程度提高,颜色加深。     

Enhanced coagulation of ferric chloride aided by tannic acid for phosphorus removal from wastewater

Phosphorus removal from wastewater is of great importance. In the present study, ferric chloride was selected as the coagulant, and tannic acid (TA), a natural polymer, as the coagulant aid to develop an effective coagulation process with the emphasis of phosphorus recovery from different types of wastewater. The results showed that TA can accelerate the settling speed by forming flocs with large size, reduce the residual Fe(III) to eliminate the yellow color caused by Fe(III), and slightly increase the phosphorus removal efficiency. The precipitate formed by TA-aided coagulation showed the advantage of releasing phosphorus faster than ferric phosphate, indicating the possibility of phosphorus recovery from wastewater as slow release fertilizer. To further understand the structural characteristics of the precipitate, analytical techniques such as Raman spectroscopy, X-ray photoelectron spectroscopy and matrix-assisted laser desorption ionization-time of flight mass spectrometry were employed. The analytical results indicated that TA–Fe–P complex was formed during the coagulation/flocculation processes. Solid phase in the precipitate consisted of TA–Fe–P complex, Fe–TA complex and/or ferric hydroxyphosphate.     

新型混凝剂在废水处理中的应用研究

自行研发出一种新型混凝剂,它能广泛应用于印染废水、生活污水和餐饮废水等的处理。经过一步强化混凝处理后,各种废水的COD、色度和浊度等均有良好的去除效果。混凝污泥可以再生重复利用。     

Evaluation of Al30 polynuclear species in polyaluminum solutions as coagulant for water treatment

Polyaluminum coagulant with a content of 76.8% of Al30 (PACAl30) was prepared. Its coagulation behaviors were compared with high Al13 content polyaluminum coagulant (PACAl13) and AlCl3. The species stability was studied using Al-Ferron method and 27Al NMR. The coagulation performances were investigated by studying the rate of flocs development, the turbidity removal efficiency and charge neutralization capacity under fixed pH conditions and uncontrolled pH conditions. The effect of pH on coagulation was also studied. The results show that PACAl30 are stable for using as coagulant. PACAl30 causes less pH depression than PACAl13. The charge neutralization capacity of PACAl30 is slightly lower than that of PACAl13 at pH6.8 and higher at pH 6.5. PACAl30 achieves the most effective turbidity removal in these three coagulants. And it acts effectively within a much broader dosage range and a wider pH range when compared with PACAl13. PACAl30 achieves the highest turbidity removal due to its strong flocs formation capacity. The results verify that Al30 is another highly active coagulation/flocculation species for turbidity removal.     

新型混凝剂在废水处理中的应用研究

自行研发出一种新型混凝剂，它能广泛应用于印染废水、生活污水和餐饮废水等的处理。经过一步强化混凝处理后，各种废水的COD、色度和浊度等均有良好的去除效果。混凝污泥可以再生重复利用。     

混凝沉淀法处理含砷选矿废水

某钨矿含砷选矿废水砷含量高且砷以As(V)为主要存在形态,采用混凝沉淀法处理,详细考察了生石灰、硫酸亚铁和六水三氯化铁3种混凝剂对废水中砷的去除效果。实验结果表明,在PAM投加量40 mg/L,静沉时间60 min条件下,比较分析3种混凝剂对砷的去除效果,三氯化铁为最佳除砷混凝剂。三氯化铁最佳除砷工艺条件为:pH 7.5,三氯化铁投加量986.67 mg/L,混凝反应时间25 min,PAM投加量为40 mg/L,静沉60 min,含砷选矿废水经该工艺处理后,砷去除率可达99.14%,出水砷浓度降至0.361 mg/L,达到国家污水综合排放标准(GB8978-1996)。     

Fenton-混凝法处理焦化废水的试验研究

对Fenton预氧化-混凝法联用技术处理焦化废水进行了研究，探讨了Fenton氧化阶段H2O2投加量、混凝阶段pH值以及混凝剂投加量等因素对焦化废水COD去除率的影响，确定了最佳处理条件。结果表明，Fenton预氧化一混凝法处理焦化废水取得了良好效果，COD去除率达97．5％，为该工艺实际处理焦化废水提供了实验依据。     

Preparation of macromolecular heavy metal coagulant and treatment of wastewater containing copper.

Many treatment technologies for wastewater containing heavy metals have been developed in recent years, but these technologies have some disadvantages, such as poor removing efficiency and complex operation. For this reason, a macromolecular heavy metal coagulant polyethyleneimine-sodium xanthogenate (PEX) was prepared by grafting a xanthogenate group to polyethyleneimine. It was determined that PEX has the function of removing both turbidity and copper ions. It was also determined that copper ions and turbidity have a cooperative removal effect with each other in the process of treating wastewater containing both turbidity and copper ions by PEX. The investigation showed that PEX is an amphoteric polyelectrolyte. At lower pH values, the amino groups of the macromolecule are electrically positive; therefore, turbidity is removed because of electroneutralization coagulation; at higher pH values, both amino groups and xanthogenic radical groups contribute to the removal of heavy metals, as a result of chelation. Compared with traditional chemical precipitation by calcium oxide and coagulation by an ordinary inorganic coagulant, PEX showed obvious advantages, for example, removing both turbidity and copper ions, higher removal efficiency, lower suitable pH value, and higher floc settlement velocity.