Biodegradability of terephthalic acid in terylene artificial silk printing and dyeing wastewater

As the characteristic pollutant, terephthalic acid(TA)was in charge of 40%—78% of the total COD of terylene artificial silk printing and dyeing wastewater(TPW-water). The studies on biodegradability of TA were conducted in a serial of activated sludge reactors with TPW-water. TA appeared to be readily biodegradable with removal efficiency over 96.5% under aerobic conditions, hardly biodegradable with removal efficiency below 10% under anoxic conditions and slowly biodegradable with a turnover between 31.4% and 56.0% under anaerobic conditions. TA also accounted for the majority of BOD in TPW-water. The process combined by anoxic, anaerobic and aerobic activated sludge reactor was suitable for TA degradation and TPW-water treatment. Further, the aerobic process was essentially much more effective than the anaerobic or anoxic one to degrade TA in TPW-water.

Stability of expanded granular sludge bed process for terylene artificial silk printing and dyeing wastewater treatment

Terylene artificial silk printing and dyeing wastewater(TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular sludge bed(EGSB) process. The stability of the EGSB process was firstly conducted by laboratory experiment. TA ionization was the predominated factor influencing the acid-base balance of the system. High concentration of TA in wastewater resulted in sufficient buffering capacity to neutralize the volatile fatty acids(VFA) generated from substrate degradation and provided strong base for anaerobic system to resist the pH decrease below 6.5. VFA and UFA caused almost no inhibition on the anaerobic process and biogas production except that pH was below 6.35 and VFA was at its maximum value. Along with the granulating of the activated sludge, the efficiency of organic removal and production rate of biogas increased gradually and became more stable. After start-up, the efficiency of COD removal increased to 57%—64%, pH stabilized in a range of 7.99—8.04, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted in neglectable rebound of pH, and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment.

Dyeing and printing wastewater treatment using fly-ash coated with chitosan

Printing and dyeing industry is a considerable source of environmental contamination. In this study treatment of printing and dyeing wastewater with a new type of sewage treatment agent, fly-ash coated with chitosan particles （FCCP）, was examined. The effects ofpH, stirring time, sedimentation time and temperature on color, COD, turbidity and NH3-N removal were determined. The optimum dosage of FCCP and the influence of individual factors on removal efficiency were tested. The optimum parameters determined using the L16 （45） orthogonal experiment were as follows： FCCP （weight ratio of chitosan to fly-ash 1：6） dosage, 4 g.L^-1; temperature, 35℃; pH, 4. The stirring time and sedimentation time were 20 min and 5 h, respectively. Under these optimum conditions, the color, COD and NH3-N removal ratios were 97%, 80% and 75%, respectively.

Design and Operation of the Printing and Dyeing Wastewater Treatment Project by Combination of Coagulation Sedimentation - Hydrolytic Acidification with Aeration Tank - Biological Aerated Filter - Active Sand Filter

In order to protect quality of Baiyangdian surface water and Gaoyang groundwater,the project is applied to process printing and dyeing wastewater that contains complicated compositions,high concentrations of organics and SS,and lots of pollutants difficult to degrade by microorganism. The process and operating parameters of project are optimized and debugged,and its economic and environmental benefits are analyzed.The results show that the process of coagulation sedimentation-hydrolytic acidification with aeration tank-biological aerated filter-active sand filter is applied in Gaoyang Sewage Treatment Plant. The design scale of sewage treatment plant is 120000 m^3/d. The influent is as following: COD is 669mg/L; SS is 424mg/L; NH_3-N is 8.83mg/L; TP is 6.03mg/L. After the process,the best removal rates of COD,SS,NH_3-N and TP are 93. 5%,98. 8%,97. 1% and 96. 2%,respectively. The various indexes of effluent water complied with standard A of the first order in Pollutants Emission Standard of Urban Wastewater Treatment Plant( GB 18918-2002). The processing cost is only 0. 807 yuan/m^3. As a result,the project construction and operation not only improve the environment,but also promote regional economic development. Process design and operating parameters provide an important reference value for the printing and dyeing wastewater treatment industry.

Application of New Modified Bentonite in Decolorization of Simulated Printing and Dyeing Wastewater

The problem of colority control of printing and dyeing wastewater has become a technical problem that plagues related companies.Bentonite is an adsorbent with excellent properties.Modification of bentonite with environmentally friendly substances can improve its decolorization performance.In this experiment,the simulated printing and dyeing wastewater was taken as the control object,and the bentonite was modified with environmentally friendly materials such as sodium carboxymethyl cellulose(CMC)and lignin to prepare a new modified bentonite;then the modified bentonite was used to adsorb the simulated wastewater to reduce the water colority and COD;finally the relevant design of the adsorption process was made.Results indicate that M lignin∶M CMC∶M original bentonite=1∶2∶97 had the optimum treatment effect,the optimum modification temperature was 30℃ and the modification time was 4 h;the optimum conditions for the adsorption process were:pH=5,temperature=30℃,reaction time=60 min,dosage=0.05 g of modified bentonite/mL simulated dye solution.The final removal rate of colority and COD reached 95.0% and 98.2%,respectively.Compared with the original bentonite,this new modified bentonite has greater adsorption capacity and thus has greater application value.

Production and application of a novel bioflocculant by multiple-microorganism consortia using brewery wastewater as carbon source

The flocculating activity of a novel bioflocculant MMF1 produced by multiple-microorganism consortia MM1 was investigated. MM1 was composed of strain BAFRT4 identified as Staphylococcus sp. and strain CYGS1 identified as Pseudomonas sp. The flocculating activity of MMF1 isolated from the screening medium was 82.9%, which is remarkably higher than that of the bioflocculant produced by either of the strains under the same condition. Brewery wastewater was also used as the carbon source for MM1, and the cost-effective production medium for MM1 mainly comprised 1.0 L brewery water （chemical oxygen demand （COD） 5000 mg/L）, 0.5 g/L urea, 0.5 g/L yeast extract, and 0.2 g/L （NH4）2SO4. The optimal conditions for the production of MMF1 was inoculum size 2%, initial pH 6.0, cultivating temperature 30℃, and shaking speed 160 r/min, under which the flocculating activity of the MMF1 reached 96.8%. Fifteen grams of purified bioflocculant could be recovered from 1.0 L of fermentation broth. MMF1 was identified as a macromolecular substance containing both protein and polysaccharide. It showed good flocculating performance in treating indigotin printing and dyeing wastewater, and the maximal removal efficiencies of COD and chroma were 79.2% and 86.5%, respectively.

Synergistic coagulation of bauxite residue-based polyaluminum ferric chloride for dyeing wastewater treatment

Considering that Fe,Al elements in bauxite residue are active components for water purification,an effective polyaluminum ferric chloride(PAFC)coagulant derived from bauxite residue,with Fe2O3 content>5.1%,Al2O3%>6.5%,basicity>65%,was successfully prepared.The effect of as-prepared PAFC on the zeta potential for printing and dyeing wastewater was investigated.Comparing with polyferric chloride(PFC)and polyferric sulfate(PFS)for printing and dyeing wastewater treatment,prepared bauxite residue-based PAFC exhibited the optimal performance in the aspects of chromaticity and chemical oxygen demand(COD)removal rate.Furthermore,the combination of bauxite residue-based PAFC and PFS for synergy coagulation of such wastewater demonstrated an obvious positive effect.With the proportion between as-prepared PAFC and PFS to be 2.5:1,the COD of treated wastewater could be further reduced to meet the national level A standard of China,providing a promising route to solve the problem of substandard printing and dyeing sewage outfall by a simple coagulation strategy.

Dyeing wastewater treatment with a complex adsorption-coagulation agent

To remove effectively the pollutants from printing and dyeing wastewater, a new complex adsorption-coagulation agent was developed and employed in dyeing wastewater treatment. The experimental results showed that better removals of COD, turbidity and color could be efficiently realized under the operating conditions of mixing at 150 r/min, reacting within 5 min and dosing at 15 g/L and 20 g/L, respectively. Combined with the settled sludge, the agent could be recycled for further adsorption and coagulation within 10 times. Compared to the conventional coagulants, the newly-developed agent had such merits as suitability for wide pH range of wastewater, less sludge production, reutilization of the condensed sludge and low operation cost.

Micro-electrolysis technology for industrial wastewater treatment

Experiments were conducted to study the role of micro-electrolysis in removing chromaticity and COD and improving the biodegradability of wastewater from pharmaceutical, dye-printing and papermaking plants. Results showed that the use of micro-electrolysis technology could remove more than 90% of chromaticity and more than 50% of COD and greatly improved the biodegradability of pharmaceutical wastewater. Lower initial pH could be advantageous to the removal of chromaticity. A retention time of 30 minutes was recommended for the process design of micro-electrolysis. For the use of micro-electrolysis in treatment of dye-printing wastewater, the removal rates of both chromaticity and COD were increased from neutral condition to acid condition for disperse blue wastewater; more than 90% of chromaticity and more than 50% of COD could be removed in neutral condition for vital red wastewater.

沸石咪唑酯骨架-8的制备及其对刚果红的吸附性能

为制备印染废水的吸附材料,以六水合硝酸锌和2-甲基咪唑为原材料,以去离子水作溶剂,采用水溶剂法制备沸石咪唑酯骨架-8(ZIF-8)材料。借助扫描电子显微镜、红外光谱仪、X射线衍射仪等探究ZIF-8材料的结构,测试其对阴离子刚果红染料的吸附性能,并分析其吸附机制。结果表明:ZIF-8颗粒大小均匀,表面光滑,呈多面体结构;其热裂解温度为258℃,具有良好的热稳定性;ZIF-8对刚果红的吸附更符合准二级动力学模型和Langmuir吸附等温线模型,即以化学吸附为主且吸附位点等效;吸附过程为自发进行的放热反应,低温有利于吸附;在温度为20℃、pH值为7的条件下,ZIF-8对95 mg/L的刚果红溶液的吸附效果最佳,吸附量可达671.41 mg/g。

海藻酸钠固定漆酶复合淀粉处理模拟印染废水的应用

采用固定漆酶的海藻酸钠-钙离子交联水凝胶球与阳离子淀粉按质量比1∶1形成新型复合吸附剂,用于对模拟刚果红染料废水的研究。考察如吸附剂投加量、反应时间、pH值等条件对模拟印染废水吸附效果的影响。结果表明,在体积50 mL、转速125 r·min^(-1)的条件下,吸附剂用量为0.6 g、吸附时间30 min、pH值在6~7、反应温度为30℃、刚果红溶液初始浓度为100 mg·L^(-1),脱色率达到96.11%,吸附量为164.2 mg·g^(-1)。对比Freundlich吸附等温方程(R^(2)=0.9899)和Langmuir吸附等温方程(R^(2)=0.9982),表明此处理过程等温拟合模型更符合Langmuir吸附模型,为单层吸附。

基于神经网络的印染废水处理组合工艺系统构建

印染废水含有多种复杂的有机物质和重金属,处理难度较大,传统的处理技术往往难以达到理想的处理效果。近年来,人工智能技术为高效、精准的废水处理提供了新的解决方案,其中,神经网络以其强大的数据处理能力和模式识别功能可以优化处理工艺,提高处理效率,并降低运营成本。基于神经网络技术的印染废水处理组合工艺系统进行深入探讨,以期为印染行业提供一种更为高效、可持续的废水处理新方案,促进环保技术的应用和环境质量的改善。

改性高岭土处理模拟印染废水效果研究

本文采用煅烧方法活化高岭土,采用聚合硫酸铁处理煅烧活化后的高岭土,通过对比2种高岭土的表征,利用它们处理大红染料模拟印染废水的色度,分析2种高岭土表征对模拟印染废水色度处理效果的相关性。结果表明,聚合硫酸铁改性煅烧活化后的高岭土比煅烧活化高岭土在BET表面积、吸附体积及BJH吸附平均孔径的数据显示更优,而运用聚合硫酸铁改性煅烧活化后的高岭土处理模拟印染废水色度的去除率更高,可高达99.94%。

橄榄果渣活性炭的制备及其对印染废水的降解

橄榄油生产工业产生了大量的固体废弃物——橄榄果渣(OP),该研究利用OP作为再生前驱体,采用氢氧化钾作为活化剂处理OP,将其制成一种成本低且环保的生物吸附剂(OP-AC),用于去除水溶液中的亚甲基蓝(MB)。通过单因素和响应面考察了改变制备过程中的固液比、活化时间、活化温度对MB吸附量和去除率的影响,通过红外光谱、扫描电镜、X射线、孔径分析仪和X射线衍射对所制备的OP-AC进行了表征。结果表明,当固液比为4∶5.8、活化时间为21 min、活化温度为527℃时,染料MB去除率最大为92.6%。通过对制备的OP-AC进行表征,其比表面积为278.8324 m^(2)/g,平均孔径为3.4180 nm,总孔容为0.131684 cm^(3)/g,微孔占比为79.42%。OP-AC表面含有丰富的官能团,以含氧官能团为主,包括羟基、羧基和羰基等。结果表明制备的吸附剂孔隙结构发达,表面吸附位点充裕,是一种高效、环保、低成本的生物材料,可用于去除水体中的MB。

负载型三维电极-电Fenton法处理活性艳橙X-GN废水

三维电极-电Fenton法是一种在电Fenton的基础上引入三维电极电催化技术的新型高级氧化法,在水处理中得到了广泛的应用。用过量浸渍煅烧法制备负载型三维电极,以采用该电极的三维电极-Fenton法处理活性艳橙X-GN废水。通过试验研究了pH、电压、Na_(2)SO_(4)投加量、Fe^(2+)投加量对处理效果的影响,并采用响应曲面法最优化实验条件。结果表明,当试验pH=4.7,电压为20.39 V,Na_(2)SO_(4)投加量为2.13 g/L,Fe^(2+)投加量为2.5 mmol/L时,COD和色度去除率可以达到85.41%和92.18%。负载型三维电极-电Fenton法对活性艳橙X-GN废水的色度和COD均具有较理想的处理效果。

论纺织印染废水低碳治理

纺织印染行业是废水及污染物排放量最大的工业行业之一,同时也是能源密集及碳排放高的行业;废水低碳治理已成为纺织印染行业可持续发展的重要路径。在分析印染废水处理工艺温室气体排放特征的基础上,提出依据染化料助剂推定的碳排放潜势概念;针对纺织印染废水处理工艺复杂及水质时变性大的问题,建立了基于碳氮物料平衡的废水处理工艺碳排放精准核算方法。面向废水低碳处理运行需求,总结了纺织印染废水低碳治理技术进展及发展方向。

GPTMS/TiO_(2)复合催化剂对AB1的降解机理分析

染料生产过程中产生的印染废液对环境或人体的危害较大,酸性黑1(AB1)是其中主要的有害物质之一。为了提高印染废液中AB1的处理效率,本研究提出了一种新型复合材料,作为印染废液中AB1的降解催化剂。该催化剂以TPNC与纳米TiO_(2)为主体,以CPTMS为链接剂。结果显示,TiO_(2)作为催化剂时,光照催化90 min后,溶液中的AB1质量分数仍有63.8%,以质量分数0.004%TNPC-GPTMS/TiO_(2)作为催化剂时,光照催化90 min后,溶液中AB1已被完成降解,溶液完成脱色。本研究提出的新型催化材料可以有效提高印染废液中的AB1处理速度。

大孔树脂对纺织印染废水吸附性能研究

研究XDA-11树脂对次甲基蓝纺织印染废水的吸附行为,考察吸附时间、pH值、温度、流速等对树脂吸附性能的影响。结果显示,在静态吸附条件下,调节温度48℃,pH值为11.0,吸附4.5 h,使用0.120 0 g树脂处理80.0 mL,质量浓度为50.0 mg/L的废水,废水脱色率约为99.66%。在动态吸附条件下,在常温,调pH值为11.0,吸附流速为2BV/h时,处理质量浓度为500.0 mg/L的废水,废水处理量达到126 BV,脱色率约为99.98%。用盐酸-碱性乙醇对树脂进行多次再生,再生率达70.39%以上。

改性TiO_(2)在光电协同下处理偶氮染料废水的研究进展

偶氮染料(AZO)是一类难被生物降解的水溶性高分子有机物,近些年来,由于良好的染色性能被广泛应用于印染等相关行业,但AZO废水一旦排入自然水体将会造成重大的环境污染问题。本文主要介绍了不同类型的改性TiO_(2)对AOZ废水的处理效果并分析了作用原理,对比分析了单一TiO_(2)与改性TiO_(2)的优缺点,积极探索改性TiO_(2)催化剂的催化机理,解析金属和非金属掺杂在其中的具体作用,为今后更加精准地控制掺杂金属或者非金属比例、提高催化剂效率提供科学依据和技术支持。

壳聚糖-魔芋葡甘聚糖复合絮凝剂在印染污水处理中的应用

利用改性-交联的方法制备壳聚糖/魔芋葡甘聚糖复合絮凝剂,以亚甲基蓝为例,对印染废水进行处理。探究了壳聚糖/魔芋葡甘聚糖复合絮凝剂的用量、吸附时间以及pH值对印染污水吸附率的影响。结果表明:在常温条件下,亚甲基蓝溶液初始浓度为8.0 mg/L,溶液PH为9,壳聚糖/魔芋葡甘聚糖复合絮凝剂的投加量为0.3 g,吸附时间72 h,亚甲基蓝溶液吸附率达到98.90%。