An efficient technique for dairy wastewater treatment

The aim of this study was to consider the efficiency of the electro‐Fenton process for organic compound reduction in an industrial dairy effluent. Experiments were conducted to evaluate the effect of several parameters, such as reaction time, pH, H₂O₂/Fe²⁺ molar ratio and volume fraction of H₂O₂ to dairy wastewater (mL/L), on the process performance. The Taguchi technique was applied to investigate the optimum operating conditions. The optimum chemical oxygen demand removal (93.24%) was experimentally obtained at a pH value of 7.58, reaction time of 87.13, current density of 58.5, H₂O₂/Fe²⁺ molar ratio of 3.62 and volume fraction of H₂O₂ to dairy wastewater of 1.39 mL/L.     

啤酒废水处理系统中活性污泥微型生物群落结构分析

为了分析啤酒厂废水处理系统活性污泥运行状态,选取了啤酒厂污水处理系统中不同阶段的微型生物群落结构作为研究对象。本文利用16S rDNA及18S rDNA特异性引物作为分子标记,通过PCR扩增污水处理系统中的环境生物群落DNA,以变性梯度凝胶电泳(DGGE)技术分离检测PCR产物获得微生物群落的DNA指纹图谱。研究结果显示,经过活性污泥处理的啤酒厂废水中细菌群落和真核生物群落结构发生了明显的改变。其中在细菌群落DGGE图谱中检测到21条特异性条带,而在真核生物DGGE图谱检测到10条。UPGMA聚类分析显示,进水与活性污泥中的细菌及真核群落结构十分相似(相似性>0.67),而与出水的差异较大(相似性<0.41),这表明了进水对活性污泥生物群落结构的重要影响。     

采用生物滤池--活性污泥法处理啤酒废水

某啤酒厂废水处理站设计规模为2100m3/d;进水CODcr=800～1500mg/L,BOD5=400～800mg/L,SS=300～600mg/L.采用高负荷生物滤池-活性污泥法处理工艺,运行表明出水水质达到GB8978-1988污水综合排放标准中规定的一级标准.     

超声处理对葡萄酒废水及污泥的影响

以葡萄酒废水和污泥为试验材料,通过单因素试验及正交试验研究了超声频率、功率、时间、pH等因素对废水去除化学需氧量(COD)、悬浮物(SS)及污泥破解度(DDSCOD)等方面的影响。结果表明,单独超声处理废水50 min,超声频率100 kHz、pH值为3、功率为80 W时,COD去除率为45%,SS去除率为68%;复频超声频率组合40 kHz+120 kHz,功率80 W+80 W时,能将COD去除率提高到64%;超声与芬顿或铁炭微电解联用在超声频率100 kHz、功率80 W时,能将COD去除率分别提高到73%、67%;污泥经频率为20 kHz、功率为80 W的超声处理后,提高了6.4%污泥破解度,污泥溶出的多酚、单宁等物质含量分别增加了54 mg/L、30 mg/L,且超声破解后污泥能够延缓酒精发酵中酵母衰老,将发酵周期延长了2 d、提高了酒精度0.2%vol、增加了单宁23 mg/L、降低了残糖0.16 g/L。     

印染废水生物处理中剩余污泥的处理和处置

阐述印染废水生物处理中产生大量剩余污泥的处理和处置方法以及有关技术,系统介绍了目前剩余污泥的主要处理和处置技术及其优缺点。一般处置方法为土地利用、焚烧和卫生填埋;处理新技术有湿式氧化法、超声波处理技术、高速生物反应器和利用矿山采空区消纳剩余污泥;污泥减量化技术则包括膜生物反应器、臭氧法、微生物捕食法和水解酸化工艺。     

降低植物油厂废水处理过程中污泥产率的措施与应用

植物油厂废水处理过程中污泥产生量大,降低废水处理过程中的污泥产率,不仅可以降低成本,还可以降低环保风险。结合实际应用经验,对植物油加工废水特征进行了分析,并结合废水处理工艺特点,对污泥产生的各个环节进行了分析。通过优选破乳剂收集废水中的可利用成分,降低加药量,采用合适的生化处理工艺,选择高效的污泥脱水处理设备等措施,可成功地将污泥产率控制在较低的水平,且可回收较多的废油皂。     

Production of polyhydroxyalcanoates (PHAs) using milk whey and dairy wastewater activated sludge: Production of bioplastics using dairy residues

The production of polyhydroxyalcanoates (PHAs), which are biodegradable plastics, was studied using milk whey and dairy wastewater activated sludge to define a suitable C/N ratio, the pre-treatments required to reduce the protein content, and the effect of pH correction. The results show good production of PHAs at a C/N = 50 and without pH correction. The use of dairy wastewater activated sludge has the advantage of not requiring aseptic conditions.     

Nitrate content of lettuce (Lactuca sativa L.) after fertilization with sewage sludge and irrigation with treated wastewater

A romaine-type lettuce (Lactuca sativa L.) was cultivated over three crop seasons (spring 2005, spring 2006 and autumn–winter 2006) in six 36 m² plots in Alcázar de San Juan, Spain. A drip irrigation system was used to water all plots: five plots with drinking water and one plot with wastewater from the activated sludge system of a wastewater treatment plant (WWTP). One drinking water-irrigated plot was not fertilized (control). Five different treatments were applied to the soil: three organic mixtures (sewage sludge, sewage sludge mixed with pine bark and municipal solid waste with composted sludge) and a conventional fertilizer were applied to the four plots irrigated with drinking water. The last plot was irrigated with treated wastewater. The treatments were tested for their effect on plant growth and nitrate concentration in vegetable tissue. An increase in fresh weight in the lettuce was linked to the dosage of sewage sludge. The highest nitrate level was observed in the sewage sludge treatment in all crops and seasons, although, in general, all values were below the maximum limits established by the European Commission for nitrate content in fresh romaine lettuce. In the third crop season, a significant increase in nitrate content was observed in lettuce from organic treatments. Nitrate concentration in lettuce from irrigated treated wastewater was higher than control, although significant differences were not found.     

活性污泥-浸没式超滤-反渗透在针织印染废水回用处理中的应用

采用活性污泥-气浮+浸没式超滤-反渗透工艺处理针织印染废水,发现二级处理段CODCr、氨氮、总磷去除率分别达到90%、74%、89%,色度、pH值达接管要求,优于一期出水水质。深度处理段,超滤出水达到一般回用水要求,回用产水池水质完全达到针织印染各生产工艺要求。回用水处理成本低于新鲜水与废水处理费用之和,节省了水资源,提升了水重复利用率。     

ASM1模型中易降解COD的生物测定法

介绍了方波法、间歇式呼吸速率法等2种测定ASM1中易降解COD的生物测定法，并用这2种方法测定了西安市污水水质．通过实验研究表明，间歇式呼吸速率测定法操作简单、实验时间短，实用性较强．西安市污水中Ss占总COD的比例为7％～10％．     

浸没式膜生物反应器协同活性炭处理海产养殖废水效果

该文结合海产养殖废水的盐度效应特点,开展了浸没式膜生物反应器(membrane bioreactor,MBR)协同粉末活性炭(powder activated carbon,PAC)处理含盐废水的试验。考察了投加PAC对于MBR污染物去除性能及膜污染的影响;盐度变化过程中(0~35 g/L)MBR对化学需氧量(chemical oxygen demand , COD)、氨氮(ammonia nitrogen,NH+4-N)、亚硝酸盐氮(nitrite nitrogen,NO₂-N)处理效果;以及含盐废水长期作用下微生物性能、膜通量、絮体粒径的变化情况。重点分析0~5 g/L的盐度变化,本体溶液中的溶解性有机物(soluble microbile products,SMP)和污泥絮体中胞外聚合物(extracellular polymeric substances,EPS)组成及含量的变化情况。结果表明:MBR PAC对COD的去除效率比MBR高7.3%,对NH+4-N、NO₂-N去除的稳定性优于MBR;两工艺条件下膜通量随盐度变化呈现类似的趋势,即敏感期衰减,稳定期得到一定程度的恢复。养殖废水长期作用下,MBR PAC膜通量是MBR的1.5倍,MBR PAC的污泥粒径相对于MBR增加了52 μm。盐度变化过程中,PAC由于其吸附性能及絮凝能力,能吸附本体溶液中的溶解性微生物代谢产物,相对于MBR,蛋白质的含量减少了34.0%。MBR PAC适用于海产养殖废水的处理。     

氨基化纤维素的制备及对丝绸印染废水的净化处理

文章以纤维素(CE)为原料,通过戊二醛交联接枝聚乙烯亚胺(PEI),制备氨基化纤维素(CE-g-PEI),并将制备的CE-g-PEI应用于丝绸印染废水的净化处理。通过正交实验,确定其最优制备工艺条件为CE/PEI质量比1︰1,反应温度45℃,戊二醛用量1.5 g,反应3 h。此时,CE-g-PEI表面氨基含量高达17.5 mmol/g。对丝绸印染废水处理结果表明:CE-g-PEI对废水的处理效果依赖于其用量,当在100 mL废水中添加60 mg的CE-g-PEI时,废水中COD去除效率达到86.7%,其浊度也由初始的7 NTU降至3 NTU左右。所以,氨基化纤维素对丝绸印染废水具有优良的净化效果,是一种有潜力的废水处理新材料。     

从好氧污泥中筛选硫酸盐浆漂白废水降解菌株及其降解动力学的研究

将好氧污泥碎解后在LB培养基上活化培养污泥中的微生物群落,根据菌落特征差异,筛选出16种微生物菌株,考察它们对硫酸盐浆漂白废水的降解能力。结果显示,8株菌具有硫酸盐浆漂白废水降解效果,其中菌株BKPE-11效果最佳,在64h内废水COD去除率达到67.46%。研究了BKPE-11在硫酸盐浆漂白废水中的生长曲线及降解该漂白废水的动力学过程,并建立了动力学方程。     

Short communication: Comparison of growth kinetics at different temperatures of Streptococcus macedonicus and Streptococcus thermophilus strains of dairy origin

Within the genus Streptococcus, S. thermophilus and S. macedonicus are the 2 known species related to foods. Streptococci are widely used as starter cultures to rapidly lower milk pH. As S. macedonicus has been introduced quite recently, much less information is available on its technological potential. Because temperature is an important factor in fermented food production, we compared the growth kinetics over 24 h of 8 S. thermophilus and 7 S. macedonicus strains isolated from various dairy environments in Italy, at 4 temperatures, 30°C, 34°C, 37°C and 42°C. We used the Gompertz model to estimate the 3 main growth parameters; namely, lag phase duration (λ), maximum growth rate (µ_max), and maximum cell number at the stationary phase (N_max). Our results showed significant differences in average growth kinetics between the 2 species. Among the strains tested, 37°C appeared to be the optimal temperature for the growth of both species, particularly for S. macedonicus strains, which showed mean shorter lag phases and higher cell numbers compared with S. thermophilus. Overall, the growth curves of S. macedonicus strains were more similar to each other whereas S. thermophilus strains grew very differently. These results help to better define and compare technological characteristics of the 2 species, in view of the potential use of S. macedonicus in place of S. thermophilus in selected technological applications.     

光活化过硫酸钾体系下直接蓝15降解动力学及其降解机制

为探索双偶氮染料直接蓝15(DB15)在水中的降解可行性及在活性氧物种作用下可能的反应位点和迁移转化机制,利用紫外光活化过硫酸钾(UV/K₂S₂O₈)技术研究了DB15在活性氧物种作用下的降解动力学和反应机制。结果表明,双偶氮染料DB15在UV/K₂S₂O₈体系中降解符合假一级动力学,其动力学常数速率为0.010 7 min^-1, K₂S₂O₈质量浓度、底物初始浓度和反应温度对其降解动力学影响显著。利用气相色谱-质谱法对DB15在UV/K₂S₂O₈体系下降解中间产物进行初步的分离与分析,并结合DB15前线电子云密度(FEDs)的理论计算结果对其降解途径进行推导。研究发现:DB15在硫酸根自由基($SO_4^-为探索双偶氮染料直接蓝15(DB15)在水中的降解可行性及在活性氧物种作用下可能的反应位点和迁移转化机制,利用紫外光活化过硫酸钾(UV/K_2S_2O_8)技术研究了DB15在活性氧物种作用下的降解动力学和反应机制。结果表明,双偶氮染料DB15在UV/K_2S_2O_8体系中降解符合假一级动力学,其动力学常数速率为0.010 7 min~(-1),K_2S_2O_8质量浓度、底物初始浓度和反应温度对其降解动力学影响显著。利用气相色谱-质谱法对DB15在UV/K_2S_2O_8体系下降解中间产物进行初步的分离与分析,并结合DB15前线电子云密度(FEDs)的理论计算结果对其降解途径进行推导。研究发现:DB15在硫酸根自由基(SO_4~-·)、羟基自由基(·OH)等活性氧物种作用下N_(11)、N_(24)、N_(41)、N_(42)和C_(28)等活性位点易被自由基直接攻击或者发生电子转移反应,从而引起DB15分子中NN和C—N键断裂,然后中间产物再进一步羟基化是其主要的降解途径。