乳品生产废水处理

介绍了混凝沉淀-水解酸化-SBR工艺处理乳品生产废水的设计、调试、运行情况以及主要工艺设备。运行结果表明,在进水的SS、CODCr、BOD5、NH3-N的质量浓度分别为300～1000、800～3000、350～1500、25～70mg/L时,其处理出水的SS、CODCr、BOD5、NH3-N的平均质量浓度分别为7、12.29、1.78、9.3mg/L,达到了污水综合排放标准(GB8978-1996)的一级标准。该工艺具有占地面积小,处理效率好,运行费用低等特点,能广泛应用于乳品生产废水的处理。     

Studies on electrochemical treatment of dairy wastewater using aluminum electrode

This study reports results of electrochemical treatment to the synthetic dairy wastewater using aluminum electrode. Response surface methodology with four factors and five level full factorial central composite design has been used to design the experiments. Four operational parameters, namely current density (J): 61.73–308.64 A/m²; dosage of sodium chloride (NaCl) (m): 0–2 g/l; electrolysis time (t): 10–90 min and initial pH (pH_o): 5–11, have been taken as input parameters and percentage chemical oxygen demand (COD) removal (Y₁) and the specific energy consumed (kWh per Kg of COD removed, Y₂) have been taken as responses of the system. Multiresponse optimization technique has been applied to find values of operational parameters which maximize the Y₁ and simultaneously minimize Y₂. The optimum values of operational parameters were found to be J = 123.46 A/m², m = 2.0 g/l, t = 74 min, and pH_o = 6.5. Optimum Y₁ and Y₂ were found to be 70.91% and 1.32 kWh/kg COD removed. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

不同运行方式对微生物燃料电池处理氨氮废水的影响

微生物燃料电池(MFC)是一种既能去除污染物又能产电的新型污水处理技术,由于其具有利用生物转化能量的节能优势,MFC废水脱氮处理技术引起了更多的关注。本实验在启动MFC的同步硝化与反硝化(SND)后,首先研究了通路与断路条件对MFC产电脱氮的影响,结果表明:断路时有利于硝化反应的发生,氨氮去除率有最大值95.17%;而通路更有利于COD和总氮的去除,表明氮的去除主要依靠阴极接受电子进行。随后分析了曝气阶段+停曝阶段运行方式对MFC产电和脱氮的影响,结果显示:曝气8.5h(DO为4.0mg/L)后停止曝气,停曝阶段为11.5h,DO逐渐降低到2.0mg/L,输出电压由无曝气运行的31mV提高到120mV左右,氨氮去除率最高达到86.42%、总氮去除负荷由无曝气运行的0.064g/(L·d)升高到0.46g/(L·d)。说明曝气阶段+停曝阶段运行方式既能有效提高MFC脱氮产电性能又可以减少维持高浓度DO的能量输入。     

新型厌氧反应器+厌氧MBR处理乳品废水的实验研究

开发了新型复合式厌氧工艺,它由新型厌氧反应器和厌氧膜生物反应器(MBR)两个单元组成,实验用水经过新型厌氧反应器的前处理再经过厌氧MBR的深度处理,检测后排放。实验中以人工配制乳品废水作为进水,对整套系统的运行状况及特性进行了分析,结果表明,人工配置乳品废水在经过新型厌氧反应器+厌氧MBR的系统处理作用后出水水质得到大幅度改善,系统运行稳定,处理效果较好。实验通过对两种废水处理工艺进行效益对比,得出新型厌氧反应器+厌氧MBR无论在经济效益方面还是在社会环境效益方面,都具有一定的竞争优势。     

Farm-scale carbon and nitrogen fluxes in pastoral dairy production systems using different nitrogen fertilizer regimes

Nutrient Cycling in Agroecosystems - The nitrogen (N) fertilizer application rate (kg ha?1 year?1) in pastoral dairy systems affects the flow of N through the soil,...     

Fenton试剂深度处理胃必治制药废水

胃必治制药废水COD值高且负荷变化大,pH值低,是一种难处理的有机废水。经常规工艺处理后,出水有时仍难达标。采用Fenton试剂对出水进行了氧化降解研究,通过测定废水的COD、UV254值变化以评价氧化的效果,考察了常压下Fenton试剂配比、投加量、氧化时间、温度等因素对制药废水处理效果的影响,初步发现了其氧化规律。在单因素试验的基础上采用正交试验方案,确定最佳工艺条件为:浓度为1mol/L的FeSO4与质量分数为3%的H2O2的体积比为1:2、投加量为150mL/L、反应时间为90min、反应温度为60℃、pH值为3。COD的去除率达到89.50%,出水COD的质量浓度降到了66mg/L以下,达到国家排放标准要求。     

小球藻对奶牛场沼液处理能力及生物质生产的探究

为资源化处理奶牛场沼液、探究小球藻Chlorella vulgaris NIES-227对奶牛场沼液的处理能力以及生物质利用潜力,在柱式光生物反应器中利用小球藻处理沼液占比分别为25%、50%、75%和 100% 4种不同浓度的未灭菌污水。研究结果显示,各浓度污水中总氮、总磷和COD的去除率分别为36.0%～92.5%、42.8%～100%和6.9%～32.2%。在沼液占比为25%的污水中氮磷的去除率最高,氨氮、总氮和总磷的去除效率分别可达99.9%、91.0%和100%。微藻在低浓度沼液（25%～50%）中生长状态良好,在沼液占比为50%的污水中可获得最高生物质产率393.6 mg/(L·d)。但是在高浓度沼液（75%～100%）中微藻生长受到一定抑制,导致氮磷的去除效果变差。培养期间细菌的数量增长显著,促进了COD的去除。各浓度沼液生物质中总脂、总糖和蛋白质含量分别为13.2%～32.2%、12.3%～27.6%和16.2%～30.9%。实验数据表明,低浓度沼液能产生更多高能量组分的生物质,适合用作生物燃料的开发;高浓度沼液能产生含较多蛋白质的生物质,更适合用作动物饲料。     

不同氮源对热带假丝酵母处理苎麻生物脱胶废水的影响

利用热带假丝酵母(C.tropicalis)处理苎麻生物脱胶废液,研究了不同种龄及不同氮源(尿素、草酸铵、硫酸铵、磷酸氢二铵、氯化铵)条件下,热带假丝酵母对苎麻生物脱胶废水的处理效果及单细胞蛋白的产量(以菌体干重计)。结果表明:种龄对于废水COD去除率的影响不大,但对单细胞蛋白生成量的影响较大,兼顾二者,以28 h种龄的菌的处理效果最佳;在试验供试的替代氮源中,磷酸氢二铵对于苎麻脱胶废水COD的去除和单细胞蛋白的产量最为有效,是替代蛋白胨的理想氮源。     

Enhanced lipase production from Aeromonas sp. S1 using Sal deoiled seed cake as novel natural substrate for potential application in dairy wastewater treatment

BACKGROUND: Sal (Shorea robusta) deoiled seed cake extract (SDOCE) was assessed for its suitability as a cheap natural substrate for lipase production under submerged fermentation. The bacterial isolate Aeromonas sp. S1 isolated from dairy industry was used for lipase production. Both the isolate and its lipase were shown to be potential tools for treatment of dairy wastewater containing higher organic load. RESULTS: On substituting tributyrin with SDOCE, lipase production was enhanced 24‐fold (195 U mL^?1) compared with the initial 8.13 U mL^?1 lipase activity. Maximum lipase production was obtained at pH 8.0 and incubation temperature 30 °C. The lipase had pH and temperature optima of 10.0 and 55 °C, respectively. The isolate and its crude enzyme preparation were checked separately for applicability in dairy wastewater treatment. The isolate was able to reduce chemical oxygen demand (COD) by 93%, oil and grease (O&G) by 75%, and total suspended solids (TSS) by 47% after 96 h of treatment. Enzymatic preparation gave 86% reduction of COD after 12 h and 75 and 45% reduction of O&G and TSS, respectively, after 96 h of treatment. CONCLUSION: Overall, the study shows the usefulness of Sal seed deoiled cake, a cheap agro‐industrial by‐product for the production of lipase. The isolate and its lipase can also be used effectively for the treatment of dairy wastewater. Copyright © 2011 Society of Chemical Industry     

Experimental and theoretical study of membrane-aerated biofilm reactor behavior under different modes of oxygen supply for the treatment of synthetic wastewater

This study compares, experimentally and theoretically, five different modes of supplying oxygen to a membrane-aerated biofilm reactor (MABR), and search for the more efficient ways of treating wastewaters. A single-tube MABR was used to measure the decrease of an organic substrate (sodium acetate) in water by supplying oxygen in different modes, namely: (1) by feeding the membrane tube either with oxygen or air (or none of them); (2) in some cases by simultaneous sparging air to the residual water. The dynamics of the substrate and oxygen consumption were measured during the batch experiment, and two mathematical models are developed to predict their transient responses using a Monod kinetic with dual substrate limitation. The models predict biomass growth and the production of extracellular polymer substances (EPS), which in turn causes the biofilm to grow; they account for the counter-diffusion of substrate and oxygen within the EPS structure that contains the cells, and one of them incorporates the mass transport by convection and diffusion in the surrounding liquid contained inside the interconnected pores and channels within the biofilm. Transport and kinetic parameters are estimated from experiments, and both models successfully predict concentration measurements in some of the set of experiments. It was found that all of the modes of oxygen supplied in a MABR were more efficient than the traditional suspended cell process.     

膜分离技术在乳化态含油废水处理中的应用研究进展

总结了乳化态含油废水处理的难点,剖析了膜处理含油废水的基本原理、膜的分类以及膜的制备与改性,并讨论了油水分离膜的长效抗污问题和解决方法。从膜分离机理、膜的分类、制备与改性等多个方面介绍了膜分离技术应用于乳化态含油废水处理的研究进展,对膜处理乳化油的现状和未来发展方向进行了总结和展望。指出利用膜表面特殊润湿性协同破乳进而高效分离乳化态油水混合物是未来膜分离技术处理乳化态含油废水的研究重点。     

精对苯二甲酸生产废水处理及回用技术探讨

针对精对苯二甲酸(PTA)生产过程产生的废水有机物成分复杂、化学需氧量高的特点,探讨了目前PTA生产废水处理技术的研究与应用情况。介绍了国内PTA废水处理的预处理技术、生化处理技术以及废水处理组合工艺技术,分析了各种处理技术的优点与缺点,指出PTA废水处理技术应朝着高效、无害、资源化利用的方向发展。     

Mesophilic and thermophilic biomethane production by co-digesting pretreated petrochemical wastewater with beef and dairy cattle manure

The use of pretreated petrochemical wastewater as provender wastewater for anaerobic degradation was explored in a continuous stirred tank reactor with dairy and beef cattle manure, under both mesophilic and thermophilic states. The co-digestion of the wastewaters contributed 50% enhancement in methane production, followed by a 98 ± 0.5% reduction in chemical oxygen demand at 10 days hydraulic retention time. No VFA aggregation was identified. In comparison with the digestion of PWW alone, methane yield increased by 50–60% under mesophilic conditions and 50–65% under thermophilic conditions due to co-digestion.     

Fenton法＋活性炭吸附处理苯海因生产废水的研究

苯海因生产废水中CODcr、挥发酚等污染物浓度都比较高,采用三级Fenton＋活性炭吸附处理后,CODcr、挥发酚均能达到国家一级排放标准。     

A comprehensive study on wastewater treatment using photo-impinging streams reactor: Continuous treatment

The degradation of phenol was investigated in a continuous flow impinging streams system. In the first step, statistical experimental designs were used to optimize the process of phenol degradation in a photo-impinging streams reactor. The more important factors affecting phenol degradation (p<0.05) were screened by a two-level Plackett-Burman design. Four of the latter parameters, namely phenol concentration, catalyst loading, pH and slurry flow rate, were selected for final process optimization, applying central composite design (CCD). The predicted data showed that the maximum removal efficiency of phenol (99%) could be obtained under the optimum operating conditions (phenol concentration=50 mg l ^?1, catalyst loading=2.1 g l ^?1, pH 6.2 and slurry flow rate=550ml min^?1). These predicted values were then verified by certain validating experiments. A good correlation was observed between the predicted data and those determined by the experimental study. This may confirm the validity of the statistical optimum strategy. Finally, continuous degradation of phenol was performed, and the results indicated a higher efficiency and an increased performance capability of the present reactor in comparison with the conventional processes.     

Preparation and characterization of new tubular kaolino-illitic ceramic membrane used for dairy wastewater treatment

Low cost asymmetric tubular ceramic membrane was developed from kaolino-illitic clay collected from the region of Medenin (Tunisia). The obtained membrane was designed to be used for ultrafiltration. The effect of pore forming agent on the plasticity, porosity, pore size distribution, mechanical strength, and permeability was evaluated. The support was performed by extrusion using the raw clay and olive pomace (OP) as pore forming agent. The effect of the use of OP was noticeable; it improved the plasticity of the paste. Also it helped to ameliorate both permeability and porosity of the obtained supports. Top layer was prepared using acid activated clay suspension. The obtained membrane had gas permeability of about 13 cm³.s⁻¹.cm⁻².bar⁻¹ at a pressure of 1.5 bar and water flux of 1700 L.h⁻¹.m⁻² at a pressure of 1 bar. The final membrane was successfully used to eliminate the fat present in a solution containing 10% of milk. Regeneration of the used membrane was carried out by calcination at 550°C. The performances of the used membrane were recovered by 97% after regeneration.