Treatment of wastewater from a whey processing plant using activated sludge and anaerobic processes

Wastewater from a whey processing plant was treated in two on-site pilot plants, a three-stage activated sludge plant and an anaerobic reactor, each of which had the capacity of treating 230 L/h of wastewater. The activated sludge treatment was very effective. It reduced 99% of 5-d biochemical oxygen demand of the plant wastewater (from an average of 1062 to 9 mg/L) and 91% of total Kjeldahl nitrogen (from 109 to 10 mg/L) after a total retention time of 19.8 h. The intermediate 5-d biochemical oxygen demand reductions were 86% after 3.8 h in the first stage and 97% after another 8 h in the second stage. The completely mixed anaerobic reactor reduced only 87% of 5-d biochemical oxygen demand after 2 d of retention. However, with an additional 8 h of activated sludge treatment the total 5-d biochemical oxygen demand was reduced by 99%. Both pilot plants were operated smoothly in spite of the considerable fluctuations in pollutant levels of the plant wastewater.     

Performance and biomass kinetics of activated sludge system treating dairy wastewater

The performance and bio‐kinetic coefficients of the activated sludge process (ASP) treating synthesised dairy wastewater were evaluated in a lab‐scale setup. The step‐loading experiment showed that the chemical oxygen demand (COD) removal efficiency, in general, increased with increasing influent wastewater COD concentration from 180 to 1200 mg/L (correlation coefficient was 0.80). The COD removal efficiency ranged from almost 80–88.4% depending on the COD concentration of the influent wastewater. Also, it could be stated that the ASP was probably underfed with organics at COD concentrations <725 mg/L. Monod, Moser, Contois and Chen & Hashimoto substrate utilisation models, relating the growth of micro‐organisms to substrate utilisation, were employed to describe the bio‐kinetics of the ASP at an organic loading rate of 1200 mg/L. Amongst them, the Contois and Monod models predicted the bio‐kinetic reactions of the ASP very well with coefficient of determination (R²) values of 0.95 and 0.93, respectively. The estimated bio‐kinetic coefficients of the Contois model (on COD basis) were as follows: half‐velocity constant (0.20 mg/L), maximum substrate utilisation rate (3.13 per day), biomass yield coefficient (0.68), endogenous decay coefficient (0.07 per day) and maximum specific growth rate (2.13 per day).     

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。     

酒精废水处理工艺中氧化沟污泥的微生物菌群分析

该实验分析了酒精废水处理过程的主要指标变化,并基于Illumina MiSeq测序方法研究了氧化沟活性污泥的微生物菌群,分析污泥中微生物种类、丰度和功能。 结果表明,在酒精废水处理过程中,pH的变化较小,总磷（TP）浓度不断减小,NH4+-N浓度呈先升高后降低的趋势,化学需氧量（COD）、生化需氧量（BOD）呈先快速减小后缓慢减小的趋势。 氧化沟活性污泥中生丝微菌属（Tetrasphaera）对废水中磷元素的去除起重要的作用;陶厄氏菌属（Thauera）对废水中氮元素的去除起重要的作用;球形杆菌属（Sphaerobacter）、陶厄氏菌属（Thauera）、沙雷氏菌属（Serratia）能够降解或转化结构复杂的有机物;热单胞菌属（Caldimonas）在污泥中丰度高,但其特性和功能尚不清晰,有待更加深入地研究。     

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。     

Electrochemical oxidation as a final treatment of synthetic tannery wastewater

Vegetable tannery wastewaters contain high concentrations of organics and other chemicals that inhibit the activity of microorganisms during biological oxidations, so biorefractory organics that are not removed by biological treatment must be eliminated by a tertiary or advanced wastewater treatment. In this paper, the applicability of electrochemical oxidation as a tertiary treatment of a vegetable tannery wastewater was investigated by performing galvanostatic electrolysis using lead dioxide (Ti/PbO2) and mixed titanium and ruthenium oxide (Ti/TiRuO2) as anodes under different experimental conditions. The experimental results showed that both the electrodes performed complete mineralization of the wastewater. In particular, the oxidation took place on the PbO2 anode by direct electron transfer and indirect oxidation mediated by active chlorine, while it occurred on the Ti/TiRuO2 anode only by indirect oxidation. Furthermore, the Ti/PbO2 gave a somewhat higher oxidation rate than that observed for the Ti/TiRuO2 anode. Although the Ti/TiRuO2 required almost the same energy consumption for complete COD removal, it was more stable and did not release toxic ions, so it was the best candidate for industrial applications. With the Ti/TiRuO2 anode, the rate of tannery wastewater oxidation increased with the current density, pH, and temperature of the solution. These results strongly indicate that electrochemical methods can be applied effectively as a final treatment of vegetable tannery wastewater allowing the complete removal of COD, tannin, and ammonium and decolorization.     

Carbamazepine and its metabolites in wastewater and in biosolids in a municipal wastewater treatment plant

Pharmaceutically active compounds (PhACs) are discharged into the environment from domestic wastewater treatment plants (WWTPs). In this study, we determined the distribution of the anti-epileptic drug, carbamazepine (CBZ), and its major metabolites and caffeine in both aqueous and solid phases through different treatment processes of a WWTP. A method was developed to extract samples of biosolids using pressurized liquid extraction (PLE), coupled with cleanup of extracts using solid-phase extraction. Samples of biosolids and wastewater were analyzed for caffeine and CBZ and five of its metabolites, 10,11-dihydro-10,11-epoxycarbamazepine (CBZ-EP), 11-dihydro-10,11-epoxycarbamazepine (CBZ-DiOH), 2-hydroxycarbamazepine (CBZ-20H), 3-hydroxycarbamazepine (CBZ-30H), and 10,11-dihydro-10-hydroxycarbamazepine (CBZ-100H). The analytes were quantified using liquid chromatography-electrospray ionization tandem mass spectrometry. The recoveries of the analytes were 82.1-91.3% from raw biosolids and 80.1-92.4% from treated biosolids, and the limits of detection were 0.06-0.50 and 0.06-0.40 microg/kg on a wet weight basis for raw and treated biosolids, respectively. The behavior of carbamazepine and its metabolites, together with caffeine as a marker of domestic inputs, was investigated in the WWTP for the City of Peterborough, ON, Canada, which utilizes secondary sewage treatment technologies. CBZ, CBZ-2OH, CBZ-30H, and CBZ-DiOH were detected at concentrations of 69.6, 1.9, 1.6, and 7.5 microg/kg (dry weight), respectively, in untreated biosolids and at concentrations of 258.1, 3.4, 4.3, and 15.4 microg/kg (dry weight), respectively, in treated biosolids. However, CBZ-EP and CBZ-100H were not detected in any of the biosolid samples. CBZ and its five metabolites were detected in all wastewater samples collected from four different stages of treatment. The results showed that 29% of the carbamazepine was removed from the aqueous phase during treatment in the WWTP, while the metabolites were not effectively removed. Concentrations of caffeine were reduced by 99.9% in the aqueous phase, which appeared to be due primarily to degradation. Caffeine was also detected at concentrations of 165.8 and 7.6 microg/kg (dry weight) in raw and treated biosolids, respectively. Because of differences in hydrophobicity, CBZ is the primary analyte in biosolids, while CBZ-DiOH is the primary analyte in the aqueous phase of the wastewater. A mass balance calculation showed that the majority of CBZ and its metabolites exist in the aqueous phase (i.e., wastewater), ratherthan in the biosolids, 78 g of CBZ and its metabolites enters the Peterborough WWTP daily, and 91 g is discharged from the WWTP daily in the combined suspended solids and aqueous phases of the wastewater. The calculated daily inputs into the WWTP are somewhat less than the inputs of 192 g estimated from Canadian annual sales data for CBZ.     

供气式低压射琉曝气氧化沟处理造纸中段废水

介绍了采用低压射流曝气系统的改良氧化沟工艺处理造纸废水的设计及调试运行。运行结果表明,此工艺设计合理,投入运行后效果良好,出水水质均可达到《造纸工业水污染物排放标准》（GB3544—2008）要求。     

Photocatalytic oxidation using a new catalyst--TiO2 microsphere--for water and wastewater treatment

Since the suspended TiO2 powder enjoys free contact with UV irradiation in a photoreactor system, it can generally achieve better efficiency than the immobilized TiO2 catalysts. However, the separation and reuse of this catalyst powder from treated water often limit its application in practice. In this study, a new type of TiO2 catalyst called TiO2 microsphere was prepared by a sol-spraying-calcination method, which can easily settle in its aqueous suspensions under gravity. The SEM image of the TiO2 microsphere samples demonstrated that they had an almost spherical shape with a particle size of 30-160 microm, while the XRD analysis indicated that these TiO2 microspheres still had a crystal size of 8.1 nm. Since these TiO2 microspheres had a porous structure with higher specific surface area and pore volume than normal TiO2 powders, they appeared to have strong adsorption ability in its aqueous suspensions. The photocatalytic activity of the TiO2 microspheres was evaluated in the photodegradations of salicylic acid (SA) and sulfosalicylic acid (SSA). The experimental results showed that the reaction rate using the TiO2 microspheres was similar to that using the TiO2 powders in the SA suspensions and even higher than that in the SSA suspensions. Chemical and physical properties of the TiO2 microspheres and powders that are attributed to photoactivity were discussed based on the Langmuir-Hinshelwood kinetic model. The prepared TiO2 microsphere samples were reused in the photooxidation reaction more than 50 times. It was found that there was no significant weakening in their photoactivity and no change in their particle shape. This TiO2 microsphere catalyst can be simply used to conduct an effective photooxidation in its suspension for water and wastewater treatment with ease of recovery from treated water.     

Determination of kinetics and stoichiometry of chemical sulfide oxidation in wastewater of sewer networks

A method for determination of kinetics and stoichiometry of chemical sulfide oxidation by dissolved oxygen (DO) in wastewater is presented. The method was particularly developed to investigate chemical sulfide oxidation in wastewater of sewer networks at low DO concentrations. The method is based on continuous measurement of the reactants allowing the kinetics to be determined at varying reactant concentrations during the course of the experiment. The kinetics determined was simulated by a rate equation. The precision of the method was assessed in terms of the standard deviation of the kinetic parameters determined in a triplicate experiment. The kinetic parameters determined in 25 experiments on wastewater samples from a single site exhibited good constancy with a variation of the same order of magnitude as the precision of the method. It was found that the stoichiometry of the reaction could be considered constant during the course of the experiments although intermediates accumulated. This was explained by an apparent slow oxidation rate of the intermediates. The method was capable of determining kinetics and stoichiometry of chemical sulfide oxidation at DO concentrations lower than 1 g of O2 m(-3).     

Mycobacterium behavior in wastewater treatment plant, a bacterial model distinct from Escherichia coli and Enterococci

Mycobacteria are waterborne emerging pathogens causing infections in human. Mycobacteria have been previously isolated from wastewater and sludge, but their densities were not estimated due to cultural biases. In order to evaluate the impact of wastewater treatment processes on mycobacteria removal, we used a real time PCR method. First we compared six DNA extraction methods and second we used the more efficient DNA extraction procedure (i.e., enzymatic lysis combined with hexadecyltrimethylammonium bromide-NaCl procedure) in order to quantify Mycobacterium. With the aim to identify parameters that could serve as indicator of mycobacterial behavior, mycobacterial densities were measured in parallel to those of Escherichia coli and enterococci, and to concentrations of chemical parameters usually monitored in wastewater. Mycobacterium reached 5.5 × 10? ± 3.9 × 10? copies/L in the influent, but was not detected in the effluent after decantation and biofiltration. Most mycobacteria (98.6 ± 2.7%, i.e. 2.4 ± 0.7 log??) were removed by the physical-chemical decantation, and the remaining mycobacteria were removed by biofiltration. In contrast, enterococci and E. coli were lightly removed by decantation step and mainly removed by biofiltration. Our results showed that Mycobacterium corresponds to a hydrophobic behavior linked to insoluble compound removal, whereas enterococci and E. coli refer to hydrophilic behaviors linked to soluble compound removals.     

Behavior of metallic silver nanoparticles in a pilot wastewater treatment plant

We investigated the behavior of metallic silver nanoparticles (Ag-NP) in a pilot wastewater treatment plant (WWTP) fed with municipal wastewater. The treatment plant consisted of a nonaerated and an aerated tank and a secondary clarifier. The average hydraulic retention time including the secondary clarifier was 1 day and the sludge age was 14 days. Ag-NP were spiked into the nonaerated tank and samples were collected from the aerated tank and from the effluent. Ag concentrations determined by inductively coupled plasma-mass spectrometry (ICP-MS) were in good agreement with predictions based on mass balance considerations. Transmission electron microscopy (TEM) analyses confirmed that nanoscale Ag particles were sorbed to wastewater biosolids, both in the sludge and in the effluent. Freely dispersed nanoscale Ag particles were only observed in the effluent during the initial pulse spike. X-ray absorption spectroscopy (XAS) measurements indicated that most Ag in the sludge and in the effluent was present as Ag(2)S. Results from batch experiments suggested that Ag-NP transformation to Ag(2)S occured in the nonaerated tank within less than 2 h. Physical and chemical transformations of Ag-NP in WWTPs control the fate, the transport and also the toxicity and the bioavailability of Ag-NP and therefore must be considered in future risk assessments.     

Effects of pharmaceutically active compounds on a mixed microbial community originating from a municipal wastewater treatment plant

The growth and composition of microorganisms found in a municipal wastewater treatment plant were investigated in the presence of four pharmaceutically active compounds (PhACs) [ketoprofen, naproxen, carbamazepine, and clofibric acid] in batch reactors at varying organic loadings. Overall, the data suggest that microbial growth inhibition was correlated to organic loading rather than PhAC concentration. Significant inhibition ranging from 34 to 43% was observed under the lowest organic loading for all PhACs other than clofibric acid. No inhibition was observed at the highest organic loading. Higher microbial inhibition was not observed with increased PhAC concentration for a given organic loading. These results indicatethatthe presence of PhAC may affect microbial growth especially under lower organic loading conditions. Further validation is required with additional PhACs, organic substrates, and a wider loading range. In addition, significant microbial shifts were observed in the presence of ketoprofen and naproxen. These data suggest that, in addition to their effect on overall microbial growth, PhACs may affect the microbial ecology and additional research should be carried out to identify PhACs that have the potential of affecting ecologically important microorganisms in wastewater treatment processes and aquatic environments in general.     

泸型白酒废水上流式厌氧污泥床反应工艺处理

在工业规模装置上对泸型白酒废水上流式厌氧污泥床反应工艺进行了实验研究,主要考察了pH值、容积负荷、温度、污泥量、进水固体悬浮物量和挥发性脂酸酸对化学需氧量（CODcr）去除效果的影响。结果表明,上流式厌氧污泥床反应可有效去除泸型白酒废水中的CODcr;pH值在6.2～7.8范围内CODcr去除率呈抛物线趋势,在pH值7.0左右最佳;容积负荷在8 000～10 000 mg/L范围内随负荷增大而CODcr去除率增加,之后逐渐降低;温度宜控制36～38 ℃范围内;进水固体悬浮物量宜低于1 800 mg/L;污泥量宜占总体积的20%左右;挥发性脂酸酸浓度最适范围＜2.5 mmol/L;工艺CODcr去除率达到了85%以上,处理能力满足了实际生产的要求,运行效果良好。     

基于制革废水处理厂升级改造分析

随着我国轻工业的不断发展,皮革工业崛起迅速,成为支柱行业.虽然带动市场经济,给国家创造财富,但同样造成了日益严重的水污染,为保护环境,促进行业的健康可持续发展,对废水处理厂进行科学的改造刻不容缓.以江苏某制革厂废水处理实例做出分析、设计改造、调整措施和效果进行了分析探讨.     

电芬顿氧化法处理染料废水的研究进展

文章综述了电芬顿法处理印染废水的基本原理,分析了电极材料、不同类型芬顿反应器对染料废水脱色率的影响,电芬顿法作为一类高级氧化技术,是处理染料废水的有效方法。双氧水(H2O2)是在包含支持电解质的酸性溶液中通过电化学法还原溶解氧制备的,这个氧化过程产生的羟基自由基(·OH)可以与废水中的有机污染物反应产生二氧化碳和水。另外,对阴极材料的优化不仅可以提高(·OH)/(或H2O2)的产率,而且可以节约染料废水的处理成本。因此,通过选择性研究,电芬顿法处理染料废水是经济可行的。