Application of modified wastes from phenol-formaldehyde resin and expanded polystyrene in sewage treatment processes

A solution to environmental pollution by polymer plastic wastes can be their chemical modification in to useful products. Such a new solution is the obtaining of effective flocculants for sewage treatment from chemically modified phenol-formaldehyde resin production wastes (SE and NS novolak) and expanded polystyrene wastes. Comparative analysis of flocculation properties was performed for amino derivatives of novolak wastes, synthesized sulphonated derivatives of novolak and expanded polystyrene wastes, of standard polyacryloamide and for Praestol commercial polyelectrolyte. Amino derivatives and sulphonated derivatives of polymer plastic wastes, having properties of anionic type polyelectrolytes, exhibit good flocculation properties in purification processes of sewages with a chemical composition close to that of found in the water circulating system power plant, coal-mine, and steel plant. Application of synthesised flocculants caused a decrease of turbidity, concentration of solved impurities and improved quality parameter of purified water. It was found that synthesised polyelectrolytes could be used in industrial water treatment processes.     

硫酸铝渣制备聚硅酸铝铁絮凝剂及应用性能研究

以硫酸铝渣为原料,研制出了一系列不同A1／Fe／Si物质的量比的聚硅酸铝铁絮凝剂（简称PAFsc）。考察了PAFSC的混凝、除浊、脱色等性能,并研究了A1／Fe／Si物质的量比、pH、投药量等因素对PAFSC性能的影响。处理模拟浊水时,当n（A1）／n（Fe）=2．0～4．0,n（M）／n（SiO2）=0．7～1．3时...     

聚合氯化铁的制备及其絮凝效果

以赤铁矿和工业盐酸为原料,采用盐酸酸浸和加碱聚合等方法制取聚合氯化铁絮凝剂(PFC),将其用来处理造纸废水,并与市售聚合氯化铁和碱式氯化铝絮凝剂进行比较.结果表明,在碱化度为2∶1、聚合温度为40℃、陈化时间为24h时,自制聚合氯化铁絮凝剂对造纸废水具有较好的处理效果;投加量为1.4mL/L时,造纸废水的浊度降低了99%,化学需氧量(COD)降低了69.55%,优于市售絮凝剂对造纸废水的处理效果;且三种絮凝剂用量相同时,自制的聚合氯化铁絮凝剂形成絮体的速率和沉降速率都较快.     

Regularities of flocculation of aqueous kaolinite dispersions with binary compositions of cationic polyelectrolytes

The regularities of the flocculation of kaolin suspensions with binary mixtures of cationic polyelectrolytes are studied. The relationship between the viscosity of flocculant solutions and the conditions of efficient flocculation is studied. It is established that an increase in the sedimentation rate upon the application of binary mixtures of flocculants results form their synergistic effect. The synergistic effect is assumed to be due to a reduction in the swelling coefficient of adsorbed polyelectrolyte macromolecules, which gives rise to the formation of floccules with enhanced density and strength.     

高分子重金属絮凝剂在水处理中的研究与应用

概述了高分子重金属絮凝剂在废水处理中的应用进展,包括高分子重金属絮凝剂的种类及废水处理的作用机理,并对除浊效果进行了比较。     

油田作业废水絮凝过程中Zeta电位的研究

以川中矿区典型的压裂酸化废水为研究对象,考察了溶液pH值、无机混凝剂、有机高分子絮凝剂、以及无机混凝剂与有机高分子絮凝剂共同作用对废水Zeta电位的影响,从理论上对油田废水的絮凝特点进行了表征.实验结果证明:油田作业废水适合在酸性条件下进行絮凝处理;聚硅硫酸铁和阳离子有机高分子絮凝剂能使废水颗粒表面Zeta电位明显正移;当联合使用时,先加无机混凝剂,后加有机絮凝剂,能提高污水处理质量.     

自动电位滴定法测定炼油工业污水中的氯离子

介绍自动电位滴定法测定炼油工业污水中氯离子含量。炼油工业污水样品经加热煮沸、双氧水氧化等预处理后,通过调节使其pH=2～6,以硝酸银标准溶液为滴定剂,在自动电位滴定仪上进行电位滴定。试验表明,本方法可以用来测定带色度的炼油工业污水样品,且对样品的酸碱度无苛刻要求,过量的双氧水不影响测定结果,不同浓度的标准样品其测定结果与其标称浓度无显著性差异。     

造纸污泥添加剂对麦秆灰烧结熔融特性的影响

利用灰熔点测试仪、XRD及XRF等仪器,对比研究了造纸污泥(脱墨污泥、造纸废水污泥)、城市废水污泥作为添加剂对麦秆灰熔融特性的影响,考察了烧结和熔融过程中的组分变化,分析了污泥添加剂对麦秆灰的作用机理;进一步将污泥添加剂与常规添加剂进行灰熔融特性对比研究。研究发现,添加比例控制为3%-10%,造纸污泥(脱墨污泥、造纸废水污泥)软化温度提升效果均优于城市废水污泥;在添加比例控制为5%时,造纸废水污泥对麦秆灰软化温度提升效果最好;增大添加比例过程中,造纸废水污泥Al_2O_3修饰骨架作用明显,但灰中长石类物质逐渐增多使得软化温度提升效果下降;在不同温度下,脱墨污泥主要是通过形成硅铝榴石使得灰熔点提升,造纸废水污泥则主要是通过生成高熔点物质CaSiO_3抑制低熔点硅酸盐形成,城市废水污泥升温中存在明显SiO_2晶态转变过程;使用污泥添加剂作为抗结渣添加剂具有良好应用前景。     

Grafting polyelectrolytes onto polyacrylamide for flocculation 2. Model suspension flocculation and sludge dewatering

Low-molecular-weight high-charge-density cationic poly(diallyldimethylammonium chloride) (polyDADMAC) was grafted onto high-molecular-weight nonionic polyacrylamide (PAM) via a free radical mechanism using a gamma radiation technique. The graft copolymers having various charge densities were evaluated as flocculants for titanium dioxide (TiO₂) model suspensions, and as conditioners for a pulp and paper mill sludge. Their flocculation performance was optimized with respect to polymer composition, gamma irradiation time and polymer dosage. Measurements included turbidity, particle size distribution and drainage rates. The graft copolymers showed a significant improvement over the homopolymers and dual polymer systems in their flocculation and sludge dewatering performance. Received: 6 April 1998 Accepted in revised form: 28 August 1998     

改性污泥与无烟煤成浆性的研究

采用阴离子表面活性剂萘磺酸钠甲醛缩合物、聚羧酸钠作为分散剂,考察了不同污泥用量时污泥煤浆的成浆性能。结果表明,当污泥(干基)添加量为煤质量的4%时,成浆浓度超过60%,随着污泥用量的提高,污泥煤浆的成浆浓度降低。污泥加入后,浆体的稳定性增强,污泥比例越高,产生沉淀的时间延长。当污泥(干基)添加量为煤质量的4%时,产生沉淀的时间超过160h,与使用稳定剂效果相当。使用不同添加剂制备的污泥煤浆均呈假塑性。污泥疏松的絮状结构,蜂窝状的外表面,强大的吸水性是造成污泥煤浆成浆浓度下降,稳定性增加的主要原因。     

Spectrophotometric determination of polymeric flocculants in waters of different types

Previously studied reactions of the formation of ion associates between polyallyldimethylammonium chloride (PADAC) and triphenylmethane dyes were used in the determination of the residual concentration of polymeric flocculants. Rapid procedures were developed for analyzing hydrochemical objects of different types without the separation of PADAC and the effect of interferents was taken into account. The analysis of process solutions of water treatment was performed using the reaction with Xylenol Orange; the analysis of potable water and purified sewage waters was based on the reaction with Erythrosine. The precision of the procedures is at a level of RSD ≤ 20%. The systematic error does not exceed the tolerable level if the concentrations of metals and surfactants in the studied water are lower than their maximum permissible concentrations.     

Investigation of catalyst Ni/K<Subscript>2</Subscript>O-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> for vapor conversion of methane

An effect of raw material (aluminum oxide and hydroxide), of amount, and of technique of KOH feed (solid or solution) on a composition of potassium aluminates formed at calcination. Reactivity of the obtaining catalysts at the vapor conversion of methane was studied.     

聚合硅酸氯化铝的研制

应用硅酸钠、氯化铝在一定条件下制成聚硅酸氯化铝 ( PASC)絮凝剂 ,并对其稳定性 ,Si O2 百分含量 ,Al/Si摩尔比等进行了研究 ,得出影响 PASC稳定性的主要因素有二 :一是溶液中的 Si O2 浓度 ,当 Si O2 的浓度在1 %左右时 ,溶液的凝胶时间在 3 0 d以上 ,而当 Si O2 浓度在 3 .0 %时 ,其絮凝时间仅为 1 0 d;二是 Al/Si摩尔比 ,最佳摩尔比约为 1 .5。对制得的 PASC进行了处理污水 (浑浊水、剩余氨水 )的条件实验 ,得出聚硅酸氯化铝对剩余氨水中 COD的去除率可达 94.1 % ,对氨氮的去除率达 93 .8% (二次絮凝 )。 PASC处理废水的适宜操作参数为 :投加量 1 3× 1 0 - 6 ,p H值为 6～ 7,高速搅拌 ( 1 3 0 0 r/min) 2 min,低速搅拌 ( 60 r/min) 1 0 min,静置沉淀 3 0 min～ 60 min。     

Kinetics and mechanism of flocculation of bentonite and kaolin suspensions with polyelectrolytes and the strength of floccs

The effects of cationic (Zetag 7589, Zetag 8660, and SNF 528) and anionic (Magnafloc 1011) polyelectrolytes, as well as the regimes and intensity of suspension stirring, on the kinetics of formation, disruption, and subsequent regrowth of aggregates of bentonite and kaolin particles, are studied in a flow system. The optimum polymer doses and the stirring conditions providing the formation of largest and strongest floccules are found. Under comparable conditions, the effect of the adsorption of the above polymers on the electrokinetic potential and the degree of aggregation of particles is studied. It is shown that intense flocculation takes place long before the isoelectric point of particles is reached. This allows one to conclude that the formation of polymer bridges plays a significant role in the flocculation of the examined suspensions with polyelectrolytes. Different dependencies of flocculation on the dose of added polyelectrolytes have been found for diluted and concentrated suspensions. This is explained by different extents to which flocculants adsorbed on the particle surface approach the equilibrium state at different concentrations of dispersed phases.     

Clarification of kaolin suspension and turbid natural water in the presence of Praestols and aluminum sulfate and aluminosilicate coagulants

The kinetics of clarification of a kaolin suspension and turbid natural water in the presence of coagulants (aluminum sulfate and aluminosilicate) and flocculants (nonionic, cationic, and anionic Praestols) was studied in relation to the concentrations of coagulants and flocculants.     

Polyacrylamide Grafted Carboxymethyl Tamarind (CMT-g-PAM): Development and Application of a Novel Polymeric Flocculant

Water is scarce commodity now. Recycling of municipal wastewater, industrial and mineral processing effluents require treatment with the inorganic or organic flocculants. Both synthetic and natural polymers are used as flocculants. Natural polymers are biodegradable and are effective at very large dosages but are very shear stable. The synthetic polymers are highly effective flocculants at very small dosages and have high tailorability, but have poor shear stability. In the authors' laboratory, a novel polymeric flocculant has been developed by grafting polyacrylamide onto the backbone of carboxymethyl tamarind (CMT-g-PAM). Various grades were developed to optimize the best flocculant. The grafted polymers were characterized by various characterization techniques such as intrinsic viscosity measurement, FTIR spectroscopy, ¹³C-NMR spectroscopy, elemental analysis etc. The flocculation studies were carried out using turbidity test as well as settling test. The optimized CMT-g-PAM was then compared with some of the commercial flocculants available in national and international markets in colloidal suspensions and it has been found that our synthesized flocculant surpasses most of the commercial flocculants in performance.     

甲基纤维素凝聚重量法测定二氧化硅

采用甲基纤维素(MC)凝聚剂重量法测定二氧化硅的含量,对溶液体积、甲基纤维素(MC)用量、温度等因素对硅酸凝聚的效果进行了优化研究,并对甲基纤维素凝聚剂与动物胶凝聚剂进行了比较。实验结果表明,在盐酸介质中,甲基纤维素对硅酸有极强的凝聚能力,甚至在室温条件下也能使硅酸大量凝聚。另外在沉淀中夹杂的铁、铝等氧化物少,操作简便,分析时间短。     

Structural characterization of C-S-H and C-A-S-H samples—Part II: Local environment investigated by spectroscopic analyses

Spectroscopic studies (¹H, ²³Na and ²⁷Al MAS NMR and Raman spectroscopy) have been used to characterize three series of C-S-H samples (0.8<Ca/Si<1.7): one C-S-H series, one aluminum inserted C-S-H series (named C-A-S-H series), and one sodium and aluminum inserted C-S-H series (named C-N-A-S-H series). Previous Rietveld analyses have been performed on the two first series and have clearly shown that (1) a unique ‘tobermorite M defect’ structural model allows to describe the C-S-H structure whatever the Ca/Si ratio and (2) the insertion of aluminum into the C-S-H structure led to the degradation of the crystallinity and to a systematic increase of the basal spacing of about 2 Å regardless the Ca/(Si+Al) ratio (at a constant Al/Si ratio of 0.1). Spectroscopic investigations indicate that the main part of the Al atoms is readily incorporated into the interlayer region of the C-S-H structure. Al atoms are mainly inserted as four-fold coordinated aluminates in the dreierketten silicate chain (either in bridging or paired tetrahedra) at low Ca/Si ratio. Four-fold aluminates are progressively replaced by six-fold coordinated aluminates located into the interlayer region of the C-S-H structure and bonded to silicate chains. Investigation of the hydrogen bonding in C-S-H indicates that the main part of the hydrogen bonds is intra-main layer, and thus explains the low stacking cohesion of the C-S-H structure leading to its nanometric crystal size and the OD character of the tobermorite like structures.     

城市生活污水化学除磷试剂的应用比较

对化学法除磷的常用试剂铝盐、铁盐和石灰在除磷原理、效果和工艺条件方面进行了比较,并就其在处理后对受纳水体的影响进行了分析评价。     

Coagulation and Flocculation Purification of Fat- and Protein-Containing Disperse Systems

Procedure for treatment of wastewater with a coagulant (aluminum sulfate) and anionic flocculants to remove fats and proteins was studied The purification efficiency was evaluated from the flocculation parameters.