Catalytic thermal treatment of desizing wastewaters

In the present study, catalytic thermal treatment (thermolysis) was investigated for the reduction of COD and color of the desizing wastewater under moderate temperature and atmospheric pressure conditions using various catalysts. The experimental runs were performed in a glass reactor equipped with a vertical condenser. The homogeneous copper sulfate catalyst was found to be the most active in comparison to other catalysts under similar operating conditions. A removal of about 71.6% chemical oxygen demand (COD) and 87.2% color of desizing wastewater was obtained with a catalyst concentration of 4 kg/m(3) at pH 4. The initial pH value of the wastewater showed a pronounced effect on the precipitation process. During the thermolysis, copper gets leached to the aqueous phase, the residue obtained after the treatment is rich in copper and it can be blended with organic manure for use in agricultural fields. The thermogravimetric analysis showed that the thermal oxidation of the solid residue obtained after thermolysis gets oxidized at a higher temperature range than that of the residue obtained from the desizing wastewater. The results lead to the conclusion that thermochemical precipitation is a very fast (instantaneous) process and would need a very small reactor vessel in comparison to other processes.     

有机超滤膜处理退浆废水实验研究

退浆废水污染物含量占到整个印染废水的一半以上,其中含有聚乙烯醇(PVA)、聚羧酸酯(CMC)、变性淀粉等高分子浆料,可生化降解性差.以退浆废水实际体系为研究对象,从截留分子量、材质和表面性质多个角度对膜进行筛选和操作条件优化,确定截留分子量为50 000 Dalton的疏水性聚砜超滤膜适合于处理退浆废水;选定0.08 MPa,70℃为处理退浆废水适宜的操作条件.该条件下超滤膜对PVA和淀粉的截留率分别为96%和87%,化学耗氧量由23 000 mg/L降低到5 700 mg/L,COD去除率达到75%.先用pH值为13的NaOH溶液清洗,再用0.2 mol/L的H3BO3溶液清洗可以使通量恢复率达到97%.     

Feasibility investigation of oily wastewater treatment by combination of zinc and PAM in coagulation/flocculation

Poly-zinc silicate (PZSS) is a new type of coagulant with cationic polymer synthesized by polysilicic acid and zinc sulfate. It has been used in several sorts of wastewaters treatment, but not used in oily wastewater treatment. In this study, we investigated the coagulation/flocculation of oil and suspended solids in heavy oil wastewater (HOW) by PZSS and anion polyacrylamide (A-PAM). The properties of PZSS cooperated with A-PAM were compared with PAC and PFS in dosages, PAMs amount, settling time, pH value and flocs morphology. The results showed that PZSS was more efficient than PAC and PFS. Under the optimum experimental conditions of coagulation/flocculation (dosage: 100mg/L, A-PAM dosage: 1.0mg/L, settling time time: 40min and pH 6.5-9.5), more than 99% of oil was removed and suspended solid value less than 5mg/L by using PZSS cooperated with A-PAM, which could satisfy the demands of the pre-treatment process for HOW to be reused in the steam boiler or recycled into the injecting well.     

Fenton's peroxidation and coagulation processes for the treatment of combined industrial and domestic wastewater

As a consequence of the population growth, major efforts have been made by the Egyptian government to construct new industrial areas. Tenth of Ramadan City is one of the most important industrial cities in Egypt. The wastewater generated from various industrial activities was highly contaminated with organic matters as indicated by COD (1750-3323 mg/L), TSS (900-3000 mg/L) and oil and grease (13.2-95.5 mg/L). All overall appraisals of the analytical data from the industrial wastewater indicate that pretreatment is required for all industrial sectors to achieve compliance with the Egyptian Environmental law which requires effective pretreatment of industrial wastewater prior to its discharge into public sewers. Treatability studies via conventional and Fenton processes have been investigated. The efficiency of conventional treatment methods led to 63% COD and 44% color removal by using FeCl(3) as coagulant. Various coagulant aids and powdered activated carbon (PAC) were added to 400mg/L FeCl(3) in order to enhance the removal of color. It was found that polyacrylamide polymer, bentonite and PAC increased the efficiency of the treatments where the color removal increased to 79%, by cationic polymer, 73% by anionic polymer, 84.5% by bentonite and 95% for 0.4 g/L PAC. Fenton process was investigated which under the operating conditions (pH 3.0+/-0.2, Fe(2+) dose=400 mg/L and H(2)O(2)=550 mg/L), color removal up to 100% and more than 90% of COD removal were achieved.     

Treatment of water-based printing ink wastewater by Fenton process combined with coagulation

Attempts were made in this study to examine the efficiency of Fenton process combined with coagulation for treatment of water-based printing ink wastewater. Parameters affecting the Fenton process, such as pH, dosages of Fenton reagents and the settling time, were determined by using jar test experiments. 86.4% of color and 92.4% of chemical oxygen demand (COD) could be removed at pH 4, 50mg/l H(2)O(2), 25mg/l FeSO(4) and 30min settling time. The coagulation using polyaluminium chloride (PAC) and ferrous sulfate (FeSO(4)) was beneficial to improve the Fenton process treated effluent in reducing the flocs settling time, enhancing color and COD removal. The overall color, COD and suspended solids (SS) removal reached 100%, 93.4% and 87.2% under selected conditions, respectively. Thus this study might offer an effective way for wastewater treatment of water-based ink manufacturer and printing corporation.     

混凝-陶瓷膜微滤处理阴极电泳漆废水研究

提出用混凝与陶瓷膜微滤组合工艺处理阴极电泳漆废水的方法,研究了pH值对CODCr去除率的影响,操作压差、膜面流速对膜通量的影响,得到了适宜的操作条件和有效的膜清洗方法.结果表明:料液pH值为6.7时,混凝过程对CODCr去除率的贡献约63%,之后的微滤使废水中CODCr的去除率增加到85%.采用平均孔径为0.2μm的氧化锆膜,在膜面流速4.2 m/s,压差0.10 MPa,温度30℃,膜稳定通量约250 L/(m2.h),渗透液可作为涂装车间循环冲洗水用.混凝作为前处理过程有助于提高膜的渗透通量,降低膜污染,改善出水水质.     

陶瓷膜-生物反应器中微生物载体的应用研究

在陶瓷膜 -生物反应器处理生活污水中引入微生物固定化技术 ,选用两种载体来固定培养微生物 ,比较了不同载体、不同孔径下的膜通量和出水水质等指标 .在操作压差 0 .1MPa,流速 2 .8m/s时 ,膜通量为 1 1 0～ 1 5 0L/(m2 ·h) ,进出水COD的去除率在 90 %以上 .     

电渗析处理L-谷氨酸废水

用电渗析法对膜拟的L -谷氨酸废水进行分离处理 ,得出描述电渗析器特性的经验模型 .并就几种因素对设备的极限电流密度和过程性能的影响进行研究 ,得出了本实验条件下适宜的操作条件 .     

Microwave enhanced Fenton-like process for the treatment of high concentration pharmaceutical wastewater

This paper explored a novel process for wastewater treatment, i.e. microwave enhanced Fenton-like process. This novel process was introduced to treat high concentration pharmaceutical wastewater with initial COD loading of 49,912.5 mg L⁻¹. Operating parameters were investigated and the optimal condition included as follows: microwave power was 300 W, radiation time was 6 min, initial pH was 4.42, H₂O₂ dosage was 1300 mg L⁻¹ and Fe₂(SO₄)₃ dosage was 4900 mg L⁻¹, respectively. Within the present experimental condition used, the COD removal and UV₂₅₄ removal reached to 57.53% and 55.06%, respectively, and BOD₅/COD was enhanced from 0.165 to 0.470. The variation of molecular weight distribution indicated that both macromolecular substances and micromolecular substances were eliminated quite well. The structure of flocs revealed that one ferric hydrated ion seemed to connect with another ferric hydrated ion and/or organic compound molecule to form large-scale particles by means of van der waals force and/or hydrogen bond. Subsequently, these particles aggregated to form flocs and settled down. Comparing with traditional Fenton-like reaction and conventional heating assisted Fenton-like reaction, microwave enhanced Fenton-like process displayed superior treatment efficiency. Microwave was in favor of improving the degradation efficiency, the settling quality of sludge, as well as reducing the yield of sludge and enhancing the biodegradability of effluent. Microwave enhanced Fenton-like process is believed to be a promising treatment technology for high concentration and biorefractory wastewater.     

扩散渗析处理化纤厂酸性废水

用均相阴离子交换膜分离废液中硫酸和硫酸钠。废酸中的悬浮物，容易造成膜污染，需要适当的预处理。试验系统的酸回收率、盐截留率、回收酸与废酸浓度比均可达70％－80％。根据试验结果给出了工业装置估算。     

Performance optimization of coagulation/flocculation in the treatment of wastewater from a polyvinyl chloride plant

This paper presents results of an experimental study of coagulation/flocculation process of wastewater generated from a polyvinyl chloride (PVC) plant. The wastewater contains fine chlorine-based solid materials (i.e. latex). Experiments were carried out using a model wastewater which is chemically identical to the actual plant but is more consistent. Inorganic ions (Al2(SO4)3, FeCl3 and CaCl2) and a water soluble commercial polyelectrolyte (PE) were added to the wastewater sample. Coagulation efficiency was determined by measuring both the turbidity of the supernatants and the relative settlement of the flocs in the jar test. It was found that aluminum and ferric ions were more efficient than calcium ions as coagulants. The addition of polyelectrolyte was found to improve substantially the coagulation/flocculation process. It was found that the (Al2(SO4)3) combined with the polyelectrolyte at certain pH and agitation speed gave the best results compared to calcium chloride or ferric chloride when combined with the same concentration of polyelectrolyte. Only 0.0375g of a solution of (0.5% Al2(SO4)3) was required to coagulate the model wastewater. Ferric chloride (2.5% FeCl3) combined with the polyelectrolyte, on the other hand, required 0.1g while the optimum turbidity is almost the same. As for calcium chloride (2.5% CaCl2) it was found to be the least effective. The coagulation/flocculation process was found to be dependent on both pH and the agitation speed.     

膜-生物反应器的研究及其在废水处理中的应用

综述了废水处理领域中的膜-生物反应器的基本特点、应用现状、存在的问题以及国内外研究的进展；重点阐述了膜-生物反应器运行工艺、新型膜材料与器件以及影响膜污染形成的因素与防治措施；并对今后的研究方向进行了展望．     

粉煤灰陶粒在污水处理中的应用进展

粉煤灰陶粒是由粉煤灰为主要原料，掺加少量粘结剂和固体燃料，经混合、成球、高温焙烧而成。由于其比表面积大、表面能高，且内部存在着铝、硅氧化物等活性点，具有良好的吸附性能，并且易于再生，便于重复利用，因此粉煤灰陶粒是一种廉价的吸附剂。综述了粉煤灰陶粒用作水处理滤料以及其在含金属离子的废水、腐殖废水、含磷废水、含氟废水、含油废水处理中的应用，并对今后的研究方向进行了展望。     

MBR在石化工业区综合污水处理中的应用

膜生物反应器是将膜分离技术与传统生化处理技术相结合的一种新型、高效的污水处理方法,具有出水水质好、设备占地面积小、活性污泥浓度高、剩余污泥量少等特点.通过对某污水处理厂选用MBR工艺处理石化区综合污水的成功运行进行分析和讨论,既指出此工艺的优势也对其存在的问题进行了分析.     

Electrochemical treatment of deproteinated whey wastewater and optimization of treatment conditions with response surface methodology

Electrochemical treatment of deproteinated whey wastewater produced during cheese manufacture was studied as an alternative treatment method for the first time in literature. Through the preliminary batch runs, appropriate electrode material was determined as iron due to high removal efficiency of chemical oxygen demand (COD), and turbidity. The electrochemical treatment conditions were optimized through response surface methodology (RSM), where applied voltage was kept in the range, electrolyte concentration was minimized, waste concentration and COD removal percent were maximized at 25 degrees C. Optimum conditions at 25 degrees C were estimated through RSM as 11.29 V applied voltage, 100% waste concentration (containing 40 g/L lactose) and 19.87 g/L electrolyte concentration to achieve 29.27% COD removal. However, highest COD removal through the set of runs was found as 53.32% within 8h. These results reveal the applicability of electrochemical treatment to the deproteinated whey wastewater as an alternative advanced wastewater treatment method.     

纳滤处理模拟电镀废水

分别以硫酸铜、氯化铜、硝酸铜溶液为模拟电镀废水进行了纳滤实验,所采用纳滤膜为Osmonics的DK、DL膜和日东电工的NTR-7450膜.实验表明,三种膜通量大小顺序为DL>DK>NTR-7450,随原料液浓度的增大膜通量降低,而膜对铜离子的截留率有升高的趋势;纳滤膜对各盐的截留率大小排序为硫酸盐>氯盐>硝酸盐.实验还考察了添加其它离子对纳滤膜通量和截留率的影响.结果表明,加入CaCl2后,对DL膜性能影响不显著;加入Na2SO4后,DL膜的通量变化不明显,截留率略有升高;加入EDTA能明显提高DL膜通量和对铜离子的截留率.     

膜法染料废水处理试验研究

采用醋酸纤维素纳滤膜,对染料厂提供的高盐度、高色度、高CODCr的染料废水进行了处理试验研究。在纳滤膜对废水中染料的截留性能、废水中无机盐（NaCl）的透过性能、纳滤膜 对染料废水中不同分子量的有机物的截留性能、以及膜对染料废水的色度和CODCr的去除性能等方面作了详细的研究和讨论。初步的研究结果表明,纳滤膜技术能有效截留废水中的染料的有机物,而废水的无机盐则几乎100％透过膜,膜对废水的色度和CODCr的去除效果亦较佳,膜技术可有效实现对高盐度、高色度、CODCr的染料废水的处理。     

纳米材料在印染废水处理中的应用进展

印染废水是一类水质水量变化大、成分复杂、色度高、生物毒性大、含多种抑制物质的难降解高浓度有机废水。印染废水的处理一直是污水治理领域的一个难题，是目前国内外水处理的难点和热点。介绍了纳米材料在印染废水处理中的应用进展情况，并对其应用前景作了展望．     

Decomposition of toxic pollutants in landfill leachate by ozone after coagulation treatment

This study deals with evaluation of organic matter from Mexico City waste sanitary landfill leachate of Bordo Poniente (including domestic and industrial) by ozonation after a coagulation treatment with Fe2(SO4)(3) (2.5 g/L at pH 4-5). The content of humic substances after the coagulation treatment decreases up to 70%. Then leachate obtained from a solid with initial COD=1511 mg/L and the pH 8.5 was treated by ozone. The aqueous samples by a UV-vis and HPLC technique were analyzed. The partial identification of the initial composition of the organic matter as well as of intermediates and final products was carried out after the extraction of the initial and ozonated leachate with benzene, chloroform:methanol (2:1) and hexane. Then the extracts with a gas chromatograph with mass detector and FID were analyzed. In the HPLC results we identify malonic and oxalic acids. The initial concentrations of these acids were 19 mg/L and 214 mg/L, respectively. The oxalic acid is formatted and accumulated in ozonation. The obtained results show that the color disappears (visually) at 100% during 5 min of ozonation. The organic substances, extracted with chloroform-methanol, may be destructed during 15 min of ozonation; the organic matter, extracted with benzene, destructs completely by ozone during 5 min, and the organic compounds extracted with hexane have a low ozonation rate. The toxic compounds presented in leachate decompose completely during 15 min of ozonation. The ozonation rate constants for each group of organics (as observed constants) were calculated applying simplified mathematical model and the recurrent least square method using the program MATLAB 6.5.     

膜法染料废水处理工艺研究

用乙酸纤维素纳滤膜 ,对染料厂的高盐度、高色度、高CODCr染料废水的处理操作条件 (进料量、压力 )、浓缩过程 (染料含量、浓缩倍率 )、膜的污染和清洗等方面进行了详细研究 .结果表明 ,用纳滤膜技术处理染料废水时 ,过程的通量随着进料流量和操作压力的升高而增大 ,并随着浓缩过程的进行即染料含量和浓缩倍率的增加而下降 ,但仍对染料保持很高的截留率 ,且在高染料浓度 (高浓缩倍率 )下 ,压力对通量影响下降 :在过程回收率达到 80 %(浓缩 5倍 )的情况下 ,膜对废水中色度和CODCr的去除率仍相当高 ;有效的膜清洗则可提高纳滤膜处理染料废水过程的效率 ,延长膜使用寿命 ,从而使纳滤膜法染料废水处理工艺技术更具实用价值 .