Removal of Organic Compounds Containing a Benzene Ring from Water by Adsorptive Micellar Flocculation

The removal of low-molecular-weight benzoic acid (benzoic acid, p-toluic acid, and salicylic acid)-derived and aniline (aniline, 4-chloroaniline, and 2,6-dimethylaniline)-derived organic compounds through adsorptive micellar flocculation (AMF) with anionic surfactants (sodium dodecyl sulfate, SDS) and aluminum sulfate was demonstrated. The interactions between SDS and the organic compounds were studied using ¹H nuclear magnetic resonance (NMR) spectroscopy. Batch AMF experiments were conducted to study the influence of several factors on target pollutant removal. For benzoic acid derivatives, the removal rate was improved by increasing the SDS and Al concentrations, while increases in the concentrations of the organic pollutant tended to decrease the removal rate. The highest removal efficiencies were observed with p-toluic acid (95.4%) > salicylic acid (84.5%) > benzoic acid (76.5%) under weakly acidic conditions due to the greater hydrophobicity of p-toluic acid and the complexation of the Al salts and the salicylic acid. The removal rates of the aniline derivatives were positively related to the SDS concentration and negatively related to the pH. At a pH of 3.0, the highest removal rates of aniline, 4-chloroaniline, and 2,6-dimethylaniline (91.3%, 98.0%, and 97.6%, respectively) were observed. For aniline compounds, charge neutralization between the SDS anions and aniline cations dominated the removal process. These findings provide new insights for the development of further applications of AMF for the removal of benzoic acid and aniline derivatives.     

Role of polymeric flocculants in sediment removal in condenser cooling systems

A proprietary water-soluble organic polymer (polymeric flocculant) of high molecular weight has been used to remove sediment from cooling water systems; current explanations of the mechanism are inadequate. A new flow-cell has been designed to study sediment-flocculant interactions under simulated practical conditions. Quantitative measurements of the conditions required for sediment removal in the flow-cell together with flocculation tests on the same systems have been made. The effects of an inorganic coagulant on the removal mechanism have also been studied. Sediment removal is interpreted in terms of flocculation theory; flocculation of a dispersed phase is found to be essential to the removal process.     

有机絮凝剂在染料中间体废水处理中的应用

采用新型絮凝剂处理染料中间体废水(色度2200：CODcr22800：pH13)色度去除率为93.2％，CODcr去除率为75．20％。废水的pH值、絮凝剂SD-1的用量、搅拌速度及时问、絮凝剂浓度对絮凝效果产生不同影响。其最佳工艺条件参数为pH=6；絮凝剂用量为0．8%;搅拌速度为100r／分；搅拌时间为4分钟；助凝剂5ppm：室温操作。     

聚合氯化铝复配絮凝剂的絮凝性能

选用聚合氯化铝(PAC)和KMnO4、MnO2进行复配处理微污染水。考察了复配比例、复配成分、反应时间对絮凝效果的影响以及絮凝沉降性能。试验结果表明:KMnO4、MnO2与PAC具有极好的复配效果,复配后浊度及有机碳总量(TOC)去除率进一步提高,絮凝沉降性能也得到改善。在浊度去除方面,要达到92.33%的去除率,复配絮凝剂比单独投加PAC节省36.8%的投加量。在TOC去除方面,单独投加15 mg/L的PAC仅能达到17.2%的去除率,而投加15.8 mg/L的复配絮凝剂则能达到47.6%的去除率。在絮凝沉降性能方面,当浊度去除要求相同时,复配絮凝剂可缩短27%~50%的反应时间。     

The synthesis of modified alginate flocculants and their properties for removing heavy metal ions of wastewater

A new flocculant was synthesized through the modification of sodium alginate with thiosemicarbazide. In the preparation, amino thiourea groups which had excellent adsorption properties for heavy metal ions were introduced to the flocculant. The structure of the flocculant was confirmed by elemental analysis, Fourier transform infrared, UV spectrophotometry, nuclear magnetic resonance, and thermal analysis. The flocculation behaviors of the flocculant for three heavy metal ions were investigated. The results showed that the removal rates of the flocculant for Pb²⁺, Cd²⁺, and Cu²⁺ reached up to 97.8%, 86.3%, and 80.0%, respectively, and the flocculation capacities were as high as 489, 215, and 160 mg/g, respectively. The excellent adsorption was ascribed to the double effects of electronic interaction and chelation between the flocculant and heavy metal ions. The flocculant had particular flocculation selectivity for Pb²⁺ in the mixed heavy metal ion solutions containing Cd²⁺or Cu²⁺, respectively. The flocculation process corresponded to Langmuir isotherm model, the flocculation kinetics agree with pseudo second order. The flocculant had potential applications for treatment of wastewater. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46577.     

壳聚糖复合絮凝剂对蔗汁酒精生产废液的澄清工艺研究

文章研究了壳聚糖和氯化铁的复合絮凝剂对甘蔗汁制取酒精产生的废液的澄清效果。考察了pH、絮凝剂用量、搅拌时间等工艺因素对废液澄清效果的影响。实验结果表明,在优化絮凝条件下,壳聚糖-铁复合絮凝剂对废液具有优良的澄清效果,COD去除率可达到60%以上。上述研究结果为蔗汁酒精废液的规模化处理提供了一定的工艺设计依据。     

壳聚糖絮凝剂处理水源水中有机物的试验研究

研究了壳聚糖絮凝剂的絮凝特性,进行了壳聚糖絮凝剂跟无机絮凝剂复合絮凝对水源水中浊度和有机物去除的试验。实验结果表明,复合絮凝能够相互促进各自的絮凝性能,显著提高有机物的去除效果,并使除浊和去除有机物得到了统一。在壳聚糖絮凝剂分别与三种常用无机絮凝剂(硫酸铝、氯化铁和聚合铝铁)的复合絮凝的效果的实验表明,其中聚合铝铁跟壳聚糖的复合絮凝剂的效果最好,在最佳条件下,其浊度、CODMn和UV254的去除率分别达到了97％、44％和55％。     

新型改性絮凝剂在含油废水处理中的应用

以聚丙烯酰胺为主链,接枝二乙胺,合成叔胺型絮凝剂(改性聚丙烯酰胺絮凝剂),对含油废水进行处理,探讨了不同搅拌速度、搅拌时间、絮凝剂以及反应物的浓度、pH值、沉降时间对COD去除效率的影响。结果表明,在改性絮凝剂用量为2.5 mL/L、pH值为6、水利条件为快速搅拌(180 r/min)4 min、慢速搅拌(90 r/min)10 min,高岭土投入量为7.5 g/L以及絮凝沉降时间为30 min的最佳絮凝条件下,改性絮凝剂对含油废水COD的去除率达到80.2%,效果较为理想。     

聚硅硫酸锌絮凝剂的制备工艺研究

以硅酸钠、硫酸锌和硫酸为原料合成了聚硅硫酸锌,研究了SiO2浓度、Zn与Si物质的量比、硅酸活化pH值、硅酸聚合时间、B与Si物质的量比等因素对聚硅硫酸锌絮凝性能的影响,得到聚硅硫酸锌絮凝剂的最佳制备工艺为:SiO2的质量分数为5%、Zn与Si物质的量之比为2.0、硅酸活化pH值1.11、聚硅酸聚合时间为1.5 h、B与Si物质的量之比为0.6。在最佳制备工艺下制备的絮凝剂用量为0.5 mL/L时,除浊率达到最大值96.1%,结果表明聚硅硫酸锌絮凝效果较好,除浊性能高,具有较强的应用性。     

复合絮凝剂(PAFSC-PAM)对制药废水的絮凝效果研究

使用PAFSC-PAM 复合絮凝剂对浙江某制药废水调节池出水原水进行絮凝实验,考察了复合絮凝剂在处理制药废水的过程中、温度、投加量、转速、pH 值对絮凝效果的影响.结果表明:使用复合絮凝剂PAFSC-PAM 比单独投加PAFSC 或PAM 具有更好的絮凝效果,并且在最优实验条件(pH值为9、快搅转速为250 r/min...     

改性木质素磺酸盐处理含镉废水的研究

用自制的改性木质素磺酸盐处理电镀含镉废水,实验表明:在室温条件下.单体用量为1.5 mol/L,反应48 h时,可得到相对分子质量较大、絮凝效果较好的改性木质素磺酸盐.当pH控制在7,改性木质素磺酸盐用量80ms/L,絮凝60 min,室温条件下,可使含镉废水中Cd~(2+)的去除率达到99%以上.     

Removal of Dyes by Biodegradable Flocculants: A Lab Scale Investigation

Abstract

In the present communication, experiments were conducted to investigate the efficiency of mucilage isolated from fruits of Coccinia indica for the treatment of simulated textile wastewater samples containing direct dyes, direct fast scarlet (DFS) and direct fast yellow (DFY) and vat dyes, golden yellow (GY) and nyanthrene yellow (NY). This mucilage (Ku) is an ecofriendly and low cost anionic polysaccharide capable of reducing color from textile effluent through flocculation process. The flocculation efficiency of Ku was improved by grafting polyacrylamide onto it. The copolymer thus obtained (Ku‐g‐PAM) showed much better flocculation capacity than that of its precursor by reducing the flocculant dose and treatment time to half. The results showed that the maximum removal was obtained at acidic pH with both the flocculants. Statistical analysis showed that the change in percent removal with pH was highly significant in case of direct dyes while it was significant in case of vat dyes removal. The plausible mucilage‐dye interaction and flocculation mechanism has been discussed.     

Removal of Direct Yellow 27 Dye by Ionic Flocculation: The Use of an Environmentally Friendly Surfactant

The presence of dyes is one of the main contributors to the organic load in textile effluents. In this study a mixture of surfactants, produced from animal/vegetable fats, was used to remove the Direct Yellow 27 dye from a synthetic wastewater through an ionic flocculation process. It was evaluated the effect of contact time, temperature, and surfactant concentration on dye removal efficiency. It was also evaluated the kinetics, equilibrium, and diffusion mechanism of the process. The kinetics of the process was well described by both Pseudo-second order and Elovich models. The transport of dye molecules to the surfactant flocs is controlled by the external layer. Equilibrium data showed a good fit to the Langmuir model. A removal rate of 93% was achieved in a single stage, after 5 h of contact time.     

絮凝剂复配处理城镇生活污水的实验研究

以实际生活污水为实验对象,利用絮凝剂PAC、PFS、CTS、阴离子PAM和阳离子PAM进行两组分或三组分复合,找出复配方案在提高COD去除率的同时降低PAC的用量。在5min搅拌,15min沉淀的短时絮凝实验中,絮凝剂复配后的絮凝效果普遍比单独加PAC好,PAC和阳离子PAM复配的COD去除率比单独加PAC高18%,成本下降40%。通过合理的絮凝剂复配能提高絮凝效果,减少絮凝剂用量,降低出水的铝离子浓度。     

Flocculation of gelatinized starch: Flocculation performance and floc characterization

The removal of single macromolecules impurity is the basis study for the promotion of flocculation technology application in the Chinese herbal medicine solution purification. We applied the flocculation process to remove gelatinized starch in solution. Three types of cationic polyacrylamide (CPAM) with different charge density were used for flocculation of gelatinized starch solution. The flocculation performance was evaluated in terms of the amylose removal ratio (AMRR), the amylopectin removal ratio (APRR), total starch removal ratio (TSRR) and supernatant turbidity (ST). The flocs were characterized by sedimentation performance, Fourier transform infrared (FTIR), scanning electron microscope (SEM) and X-ray photoelectric spectroscopy (XPS) method. The experimental results show that the flocculant CN15 has the best performance for gelatinized starch flocculation among three flocculants. According to the characterization analysis, the flocs exhibited an obvious network structure, and it is concluded that hydrogen bonding between N-H in CPAM and C-O in the starch and bridging flocculation played the essential roles in flocculation of the gelatinized starch.     

Flocculation of spin bath NMMO solution for removal of colloidal impurities in lyocell process

ABSTRACT

Evaluation of various flocculants, selection of suitable flocculant and optimization of process parameters for reduction of colloidal particles have been carried out for lyocell spin bath solution. Maximum turbidity reduction was achieved with polyacrylamide based flocculant. Experiments were carried out using lab jar tests and factorial design of experiment was applied to optimize the flocculation process parameters, i.e., flocculant dosage, mixing time and mixing speed. Operation at optimum conditions reduced turbidity by 80–90% and improved the downstream operation of ion-exchanger by 11%. Without flocculation treatment, surface fouling of ion-exchange resin was observed in Scanning Electron Microscopy.     

聚硅酸铝铁絮凝剂的研究进展

聚硅酸铝铁(PSAF)作为一种新型无机高分子絮凝剂,在除浊、脱色以及去除有机物方面具有优越的性能。文献报道的浊度、色度以及有机物的最高去除率可分别达97%、98%、87%。控制PSAF性能及稳定性的关键因素是Al/Fe/Si的摩尔比、硅酸浓度、碱化度、熟化时间等;同时,PSAF的絮凝效果还受水体参数的影响。介绍了PSAF的制备、絮凝效果及其影响因素,最后简要概括了当前研究存在的问题。     

Palm oil mill effluent pretreatment using Moringa oleifera seeds as an environmentally friendly coagulant: laboratory and pilot plant studies

This research paper covers the suitability of the coagulation–flocculation process using Moringa oleifera seeds after oil extraction as a natural and environmentally friendly coagulant for palm oil mill effluent treatment. The performance of M. oleifera coagulant was studied along with the flocculant KP 9650 in removal of suspended solids, organic components and in increasing the floc size. The optimum values of the operating parameters obtained from the laboratory jar test were applied in a pilot‐scale treatment plant comprised of coagulation–flocculation and filtration processes. Pilot‐scale pretreatment resulted in 99.7% suspended solids removal, 71.5% COD reduction, 68.2% BOD reduction, 100% oil and grease removal and 91% TKN removal. In pilot plant pretreatment, the percentage recovery of water was 83.3%, and 99.7% sludge was recovered after dewatering in a filter press. Copyright © 2006 Society of Chemical Industry     

氧化-聚硅酸锌混凝法处理厌氧生化淀粉废水的研究

采用聚硅酸锌絮凝剂处理淀粉生产废水的厌氧生化出水,试验考察了废水pH值、絮凝剂投加量、搅拌速率等因素对絮凝效果的影响,以及高锰酸钾预氧化后再絮凝处理的效果.试验结果表明,在PSAZ投加量为0.5 mL/L、pH值为8.75、快速搅拌速率为285r/min、慢速搅拌速率为60r/min的最佳条件下,废水中CODCr的去除...     

黄磷炉渣制污水絮凝剂及其应用研究

以黄磷炉渣为原料,通过硝酸溶液处理,制备得到了无机高分子活化硅酸絮凝剂,用于处理云南滇池水系的污染水,具有良好的浊度和COD去除率。通过正交实验研究了浸取温度、浸取时间、液固比和HNO3质量分数对絮凝效果的影响规律,并对实验结果进行了直观分析。研究表明:制备活化硅酸的较优条件为浸取温度70℃,浸取时间70min,液固比18∶1,w(HNO3)=15%;制备的活化硅酸絮凝剂处理滇池污染水,其浊度和COD去除率分别达98%和75%。