Anaerobic-aerobic processes for the treatment of textile dyeing wastewater containing three commercial reactive azo dyes:Effect of number of stages and bioreactor type

In this study,the effect of number of stages and bioreactor type on the removal performance of a sequential anaerobic-aerobic process employing activated sludge for the treatment of a simulated textile dyeing wastewater containing three commercial reactive azo dyes was considered.Two stage processes performed better than one stage ones,both in terms of overall organic and color removal,as well as the higher contribution of anaerobic stage to the overall removal performance,thereby making them a more energy efficient option.The employment of a moving bed sequencing batch biofilm reactor,which uses both suspended and attached biomass,for the implementation of the anaerobic stage of the process,was compared with a sequencing batch reactor that only employs suspended biomass.The results showed that,although there was no meaningful difference in biomass concentration between the two bioreactors,the latter reactor had better performance in terms of chemical oxygen demand(COD)removal efficiency and rate and color removal rate.Further exploratory tests revealed a difference between the roles of suspended and attached bacterial populations,with the former yielding better color removal whilst the latter had better COD removal performance.The sequential anaerobic–aerobic process,employing an aerobic membrane bioreactor in the aerobic stage resulted in COD and color removal of 77.1±7.9%and 79.9±1.5%,respectively.The incomplete COD and color removal was attributed to the presence of soluble microbial products in the effluent and the autoxidation of dye reduction metabolites,respectively.Also,aerobic partial mineralization of the dye reduction metabolites,was experimentally observed.

Biological Nitrogen and COD Removal of Nutrient-Rich Wastewater Using Aerobic and Anaerobic Reactors

A preliminary study on nitrogen and organic removal efficiency of a lab-scale system using aerobic and an-aerobic reactors was performed. A simulated wastewater containing elevated levels of nitrogen was used. This paper aims to compare the efficiency of aerobic and anaerobic reactors in achieving nitrogen and chemical oxygen demand (COD) removal of nutrient-rich wastewater. It also presents the start-up experi-mentation conducted on simulated wastewater using two different reactors configured as aerobic and anaero-bic. Start-up experiments were carried out using a 5-liter acrylic aerobic reactor and a 4-liter flask anaerobic reactor containing activated sludge taken from De La Salle University (DLSU) wastewater treatment plant as a source of inoculum. Simulated wastewater was continuously fed to the two reactors and the time course of biomass growth was monitored by measuring the biomass concentration represented by mixed liquor volatile solids (MLVS). The time course of organic pollutant reduction by measuring the chemical oxygen demand (COD) was conducted until steady state condition was reached. On the other hand, COD and nitrogen tests such as Ammonia nitrogen (NH3-N), Nitrite nitrogen (NO2--N), Nitrate nitrogen (NO3--N) were also per-formed using 5 batch aerobic reactors containing different concentrations of wastewater and a single batch anaerobic reactor to see the effect of different feed concentrations in the removal of nitrogen. Preliminary results showed that 98% reduction in COD was obtained in aerobic reactor, as supported by increasing con-centration of MLVS, with a hydraulic retention time (HRT) of 5 hours after 11 days while 34% reduction in COD was obtained in anaerobic reactor with the same HRT after 14 days.

Effect of aerobic and anaerobic exercises on glycemic control in type 1 diabetic youths

AIM:To evaluate the long-term effect of aerobic and/or anaerobic exercise on glycemic control in youths with type 1 diabetes.METHODS:Literature review was performed in spring and summer 2014 using Pub Med/MEDLINE,Google Scholar,Scopus,and Science Direct with the following terms:aerobic,anaerobic,high-intensity,resistance,exercise/training,combined with glycemic/metabolic control,glycated haemoglobin A1c(Hb A1c) and type 1diabetes.Only peer-reviewed articles in English were included published in the last 15 years.It was selected from 1999 to 2014.Glycemic control was measured with Hb A1 c.Studies with an intervention lasting at least 12 wk were included if the Hb A1 c was measured before and after the intervention.RESULTS:A total of nine articles were found,and they were published between the years of 2002-2011.The sample size was 401 diabetic youths(166 males and 235 females) with an age range of 10-19 years except one study,in which the age range was 13-30 years.Study participants were from Australia,Tunisia,Lithuania,Taiwan,Turkey,Brazilia,Belgium,Egypt and France.Four studies were aerobic-based,four were combined aerobic and anaerobic programs,and one compared aerobic exercise to anaerobic one.Available studies had insufficient evidence that any type of exercise or combined training would clearly improve the glycemic control in type 1 diabetic youth.Only three(two aerobic-based and one combined) studies could provide a significant positive change in glycemic control.CONCLUSION:The regular physical exercise has several other valuable physiological and health benefits that justify the inclusion of exercise in pediatric diabetes treatment and care.

Aerobic vs anaerobic exercise training effects on the cardiovascular system

Physical exercise is one of the most effective methods to help prevent cardiovascular(CV) disease and to promote CV health. Aerobic and anaerobic exercises are two types of exercise that differ based on the intensity, interval and types of muscle fibers incorporated. In this article, we aim to further elaborate on these two categories of physical exercise and to help decipher which provides the most effective means of promoting CV health.

ATP content and biomass activity in sequential anaerobic／aerobic reactors

Specific ATP content of volatile solids was measured to characterize the sludge activity in a sequential anaerobic/aerobic wastewater treatment system, with an upflow anaerobic sludge blanket (UASB) reactor and a three-phase aerobic fluidized bed (AFB) reactor. The wastewater COD level was 2000-3000 mg/L in simulation of real textile wastewater. The ATP content and the specific ATP contents of volatile solids at different heights of the UASB reactor and those of the suspended and immobilized biomass in the AFB reactor were measured. In the UASB reactor, the maximum value of specific ATP (0.85 mg ATP/g VS) was obtained at a hydraulic retention time (HRT) 7.14 h in the blanket solution. In the AFB reactor, the specific ATP content of suspended biomass was higher than that of immobilized biomass and increased with hydraulic retention time reaching a maximum value of 1.6 mg ATP/g VS at hydraulic retention time 4.35 h. The ATP content of anaerobes in the UASB effluent declined rapidly under aerobic conditions following a 2nd-order kinetic model.

Function of anaerobic portion in a conventional sequencing batch reactor

The performance of SBRs treating two kinds of wastewater(synthetic wastewater con- taining polyvinyl alcohol and effluent from a coke-plant wastewater treatment system)was investi- gated in this study,in order to examine the exact function of anaerobic portion in a conventional SBR.The set up of 4-or 8-hour anaerobic mixing period in a SBR's cycle did not benefit for PVA degradation.While an anaerobic reactor seeded with anaerobic sludge could partly hydrolyse and acidify PVA into readily-degradable intermediates.During the anaerobic fill period of an SBR treat- ing the effluent from a coke-plant wastewater treatment system,the organic concentration was re- duced to certain extent due to the adsorption of activated sludge and dilution of the mixed liquor from the previous cycle.Parts of readily-degradable organics in the influent were utilised by denitri- fiers as carbon source.The biomass in a conventional SBR was alternatively imposed to aerobic and anaerobic conditions in its operating cycle,the environmental conditions needed for anaerobic hy- drolization and acidification of refractory organics could not occur in such an SBR.

¹³C/¹²C Isotope Fractionation during Aerobic and Anaerobic Biodegradation of Naphthalene

Microcosm experiments were conducted to determine the fractionation of stable carbon isotopes during biodegradation of naphthalene. The microcosms were performed under aerobic conditions, anaerobic (amended with sulfate, amended with nitrate and with no amendments) and sterile controls. The liquid phase was analyzed to determine naphthalene concentration and stable carbon isotope signature. Aerobic microcosm showed that naphthalene degraded aerobically within 60 hours. The δ13C increased from -25.5‰ to -25.1‰ (enrichment of 0.4‰ ± 0.08‰) in a single sample in which 95% of the naphthalene was biodegraded. Anaerobic microcosms show that after 288 days, the microcosms with no amendments, amended with nitrate and amended with sulfate had consumed respectively 30%, 50% and 60% of naphthalene on average, compared to control microcosms. Under the denitrifying conditions, the δ13C of naphthalene increased from -25.2‰ to -23.9‰ (enrichment of 1.3‰ ± 0.3‰) after a 95% of naphthalene biodegradation. For the unamended microcosms, a slight enrichment on δ13C napththalene was detected, from -25.2‰ to -24.5‰ (enrichment of 0.7‰ ± 0.3‰) after a biodegradation of approximately 65% of naphthalene (after 288 days). For sulfate reducing microcosms, no significant changes were detected on the δ13C during naphthalene biodegradation.

Comparative study of thermophilic and mesophilic anaerobic treatment of purified terephthalic acid (PTA) wastewater

The paper provides a critical comparison between mesophilic and thermophilic anaerobic treatment of PTA wastewater through diagnosis of a case study. Aspects covered are bioavailability, biodegradability, microbial population, thermodynamics, kinetics involved and bio-reactor design for PTA wastewater treatment. The results of the case study suggests that one- stage thermophilic anaerobic reactor coupled with coagulation-flocculation pre-treatment unit and an aerobic post treatment unit could be techno-economically viable for PTA wastewater treatment to ensure that the final effluent quality conforms to the international standard. The in-formation emanated from this study could be useful and thought provoking to the professionals and academia in the area of PTA wastewater treatment and can serve as impetus toward the development of research lines in similar problems like the treatment of other petrochemical wastewater such as phenol-con- taining wastewater, benzene/benzoic acid-con- taining wastewater or wastewater from other similar industrial settings.

Elimination of Carbon, Nitrogen and Phosphorus in Domestic Wastewater through a Series of Anaerobic and Aerobic Reactors for a Developing Country like Benin

Waste water treatment in order to preserve water resources is one of the major concerns in developing countries. This study aims to test the operating effectiveness of a pilot designed on a basis of several laboratory experiments, which consists of an anaerobic and aerobic pond in series. The test was performed through monitoring global parameters of pollution. The results of the analysis of these parameters indicate an elimination of 91% of suspended solids, 68% of COD, 77% of BOD5, 61% of nitrate and 81% of phosphorus. It was also noticed that the anaerobic pond removes most, carbonaceous organic materials and especially suspended matters;and the aerobic pond most, nitrogen and especially phosphorus. This study reveals the effectiveness of the series connection of an anaerobic and aerobic pond for domestic wastewater treatment.

Racial variation of aerobic and anaerobic performances in sedentary men

The present study was designed to compare the effect of racial variations on short- and incremental maximal exercises in sedentary men whites (WT) and blacks (BT) Tunisian and South African (SA). In a randomized order, thirty-six physically sedentary men including 12 BT, 12 WT, and 12 SA were asked to perform a force-velocity (i.e., determination of maximal power (Pmax), F0, and V0) and a treadmill maximal aerobic (i.e., determination of maximal oxygen uptake (VO2 max)) tests. Pmax and F0 were significantly higher in SA than WT (p 0 values. Moreover, VO2 max was significantly higher in SA and BT than WT (p < 0.001). However, no significant difference was observed between SA and BT. Compared to white subjects, the present study’ results suggest the superiority of blacks races on aerobic and anaerobic exercises in physically sedentary men.

Removal of nitrogen and phosphorus in a combined A^2/O-BAF system with a short aerobic SRT

A bench-scale anaerobic/anoxic/aerobic process-biological aerated filter （A^2/O-BAF） combined system was carded out to treat wastewater with lower C/N and C/P ratios. The A^2/O process was operated in a short aerobic sludge retention time （SRT） for organic pollutants and phosphorus removal, and denitrification. The subsequent BAF process was mainly used for nitrification. The BAF effluent was partially returned to anoxic zone of the A^2/O process to provide electron acceptors for denitrification and anoxic P uptake. This unique system formed an environment for reproducing the denitdfying phosphate-accumulating organisms （DPAOs）. The ratio of DPAOs to phosphorus accumulating organisms （PAOs） could be maintained at 28% by optimizing the organic loads in the anaerobic zone and the nitrate loads into the anoxic zone in the A^2/O process. The aerobic phosphorus over-uptake and discharge of excess activated sludge was the main mechanism of phosphorus removal in the combined system. The aerobic SRT of the A^2/O process should meet the demands for the development of aerobic PAOs and the restraint on the nitrifiers growth, and the contact time in the aerobic zone of the A^2/O process should be longer than 30 min, which ensured efficient phosphorus removal in the combined system. The adequate BAF effluent return rates should be controlled with 1--4 mg/L nitrate nitrogen in the anoxic zone effluent of A^2/O process to achieve the optimal nitrogen and phosphorus removal efficiencies.

好氧-厌氧耦合法处理奶牛场污水工艺分析

【目的】筛选降解奶牛场粪污水的微生物,为奶牛场粪污处理提供科学依据。【方法】选择可用于降解污水的微生物菌株,测定微生物处理奶牛场粪污水后的化学需氧量(COD)、生物需氧量(BOD_(5))、总磷(TP)和pH的数值。【结果】从具有降解污水功能的微生物中,筛选出降解效果较好的3株好氧微生物,分别为枯草芽孢杆菌、巨大芽孢杆菌、胶质芽孢杆菌;3株厌氧微生物,分别为沼泽红假单胞菌、荧光假单胞菌、沙雷氏菌;将6种好氧-厌氧菌耦合处理降解奶牛场粪污水,其降解效率均有不同程度的提升,好氧-厌氧耦合法处理奶牛场粪污水的工艺参数为菌种接种量5%、曝气量0.05 m^(3)/h(每隔10 h曝气2 h)、温度30℃、处理时间96 h。【结论】奶牛场污水中COD去除率为91.38%、BOD_(5)去除率为96.82%、TP去除率为82.6%,出水pH值为7.2~7.6,符合国家农田灌溉水标准。

外源生物强化下水稻秸秆好氧-厌氧两相发酵产甲烷特性研究

采用生物强化方法强化水稻秸秆好氧水解过程,并研究绿色木霉及添加量(占总料液质量分数3%、5%、7%和9%)对其发酵特性的影响。好氧水解阶段生物强化时间为24 h,随后在35℃条件下进行厌氧发酵产甲烷潜力测试试验。结果表明,与对照组相比,添加绿色木霉进行生物强化各组的木质纤维素降解率、挥发性脂肪酸(VFAs)产量及产气率均有不同程度的提高,VFAs均以乙酸为主。利用Modified Gompertz对累积产甲烷量进行拟合,拟合结果较好,绿色木霉添加量为3%、5%、7%、9%的各预处理试验组累积产甲烷量分别为198.28、211.351、228.44、234.78 mL/g,比CK对照组产甲烷量分别提高18.89%、26.72%、36.96%、40.76%,添加7%绿色木霉组的综合效果最好,在此条件下半纤维素、纤维素、木质素降解率分别为36.86%、31.57%、7.43%,甲烷产量较CK组提高36.96%。好氧水解过程中优势菌群为厚壁菌门(Firmicutes)、绿弯菌门(Chloroflexi)、变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)等,其中厚壁菌门(Firmicutes)相对丰度随水解时间的延长而减少,绿弯菌门(Chloroflexi)和拟杆菌门(Bacteroidetes)相对丰度增加,表明添加菌剂能够改变菌群结构,促进好氧水解反应的进行。

填料-厌氧-好氧消化+复合酶工艺对城市污水处理及污泥减量的效能

针对当前城市污水处理要求不断提高,以及污水处理工艺产生大量污泥给后续污泥处理处置带来的困难,研究旨在开发一种污泥减量技术,既能降低污泥产率,又能保证污泥沉降性能,同时保障污水处理效果。通过对比运行试验,研究了在恒温条件下好氧-沉淀-厌氧(OSA)工艺和填料-厌氧-好氧消化工艺分别在加入与不加入高效溶胞复合酶处理下的污泥减量效果,以及对污泥上清液有机物和营养盐类的去除效能。结果表明,消化工艺经过6 d后,填料-厌氧-好氧消化+复合酶工艺的污泥降低率可达到44.0%,污泥减量效果最佳。此外,该工艺能使溶解性化学需氧量(SCOD_(Cr))维持在180~200 mg/L,pH值维持在6.8~7.0,氨氮维持在3~4 mg/L,NO_(3)^(-)-N维持在36~43 mg/L,从而保证出水水质。同时污泥容积指数(SVI)无明显变化,确保了污泥沉降性能。

Effects of aerobic training on serum paraoxonase activity and its relationship with PON1-192 phenotypes in women

Background：Paraoxonase 1（PON1） is an antioxidant enzyme that protects high-density lipoprotein（HDL） and low-density lipoprotein against oxidation.Limited studies have addressed the influenc of exercise on PON1 activity and its relationship with PON1 phenotypes.We investigated relationships between PON1-192 phenotypes,PON1 activity,aerobic exercise,and blood lipid and lipoprotein concentrations in middle-aged women.Methods：An exercise group（n=50） engaging in regular aerobic exercise and a control group（n=41） were selected from a subset of 300 Caucasian women that met the inclusion criteria.Serum PON1,salt-stimulated PON1（SSPON1）,and arylesterase（ARE） activities;cholesterol levels and ARE activities of total HDL and HDL subgroups（HDLs）（supernatants obtained by polyethylene glycol）;and blood lipid and lipoprotein concentrations were determined by standardized enzymatic methods.PON1-192 QQ（low activity）,QR（moderate activity）,and RR（high activity） phenotype groups were define using serum SSPON1/ARE activity ratios.The R-carries（RC） phenotype group consisted of the QR and RR groups combined.Results：All lipid and lipoprotein concentrations were greater in the exercise group than in the control group.Regardless of phenotype,no significan differences were observed between the exercise and control groups in terms of serum PON1,SSPON1,or ARE activity associated with HDLs（p〉 0.05）,whereas PON1 activities in QQ-phenotyped women in the exercise group were significant y higher than those in the control group（p〈0.01）,but not the RC group.A statistically significan interaction between PON1 phenotypes（QQ and RC groups） and exercise（exercise and control groups） on PON1 activity was found.Conclusion：These results showed that a regular aerobic exercise program can improve PON1 activity depending on PON1-192 phenotype,but not on lipid and lipoprotein levels,in middle-aged Turkish women.

Phylogenetic analysis of aerobic anoxygenic phototrophic bacteria and their relatives based on farnesyl pyrophosphate synthase gene

The study aims to reveal phylogenetic and evolutionary relationship between aerobic anoxygenic phototrophic bacteria（AAnPB） and their relatives,anaerobic anoxygenic phototrophic bacteria（AnAnPB） and nonphototrophic bacteria（NPB,which had high homology of 16S rDNA gene with AAnPB and fell into the same genus）,and validate reliability and usefulness of farnesyl pyrophosphate synthase（FPPS） gene for the phylogenetic determination.FPPS genes with our modified primers and 16S rDNA genes with general primers,were amplified and sequenced or retrieved from GenBank database.In contrast to 16S rDNA gene phylogenetic tree,AAnPB were grouped into two clusters and one branch alone with no intermingling with NPB and AnAnPB in the tree constructed on FPPS.One branch of AAnPB,in both trees,was located closer to outgroup species than AnAnPB,which implicated that some AAnPB would be diverged earlier in FPPS evolutionary history than AnAnPB and NPB.Some AAnPB and NPB were closer located in both trees and this suggested that they were the closer relatives than AnAnPB.Combination codon usage in FPPS with phylogenetic analysis,the results indicates that FPPS gene and 16S rRNA gene have similar evolutionary pattern but the former seems to be more reliable and useful in determining the phylogenic and evolutionary relationship between AAnPB and their relatives.This is the first attempt to use a molecular marker beside 16S rRNA gene for studying the phylogeny of AAnPB,and the study may also be helpful in understanding the evolutionary relationship among phototrophic microbes and the trends of photosynthetic genes transfer.

Effect of vacuum negative pressure aerobic hydrolysis pretreatment on corn stover anaerobic fermentation

Lignin degradation restricts corn stover anaerobic fermentation efficiency.The vacuum negative pressure aerobic hydrolysis pretreatment of corn stover was tested,and the optimal combined pretreatment conditions were presented in this paper.Because of the physical characteristics of light weight and large specific porosity of stover,it led to the formation of a scum layer during the fermentation process and thus reduced the gas production rate.In the pretreatment design,the vacuum conditions(0.02-0.08 MPa)and dwell time(5-20 min)were selected to see the changes of volumetric weight,swelling and specific porosity of corn stover,resulting in an increase of the volumetric weight by 7.18%-28.72%,an increase of the swelling by 3.18%-58.59%,and a decrease of the specific porosity by 9.34%-38.59%,as compared with the CK group.Continuous vacuum negative pressure treatment could discharge the air inside the stover destroy the microstructure,and cause the stover to settle more easily during the aerobic hydrolysis process.The optimal aerobic hydrolysis temperature and time were determined to be 39°C and 12.65 h,respectively.With the optimal pretreatment,the corn stover anaerobic fermentation test realized a cumulative methane yield of 260.44 mL/g VS,22.71%higher than CK group;meanwhile,the hydraulic retention time was shortened by 32.39%.

缺血预处理提升运动表现--方法、应用及机制

背景:缺血预处理的保护效应在医学领域已经得到广泛证实和应用,但在运动领域的使用方法、干预部位、施加压力和时长尚无统一定论,对于不同运动类型的运动表现的作用效果在相关研究间也存在一定的差异。目的:阐述国内外关于缺血预处理提升运动表现的研究现状,为缺血预处理在运动领域的应用提供最佳方法和理论支持。方法:在中国知网、万方数据、维普、Web of Science、EBSCO、PubMed和Cochrane数据库进行文献检索,以“缺血预处理、预适应、预处理、血流限制”和“运动、运动表现”为中文检索词,以“Remote conditioning,Remote ischemic conditioning,transient limb ischemia,muscle ischemia,ischemic preconditioning”“exercise performance,sport,exercise,athletes”为英文检索词,最终纳入69篇文献进行综述分析。结果与结论:①缺血预处理的干预方式分为远程缺血预处理和局部缺血预处理,常见施加部位为上臂或大腿中下1/3交界处,双侧同时或交替进行皆可,压力为220 mmHg(1 mmHg=0.133 kPa),干预时长常采用4×5 min。②缺血预处理在运动科学领域的研究集中于自行车、游泳、跑步和抗阻训练等,该方法对提升有氧耐力、无氧耐力和力量耐力的运动表现效果显著,但其对爆发力的影响仍存在争议。③缺血预处理的主要作用是在应激条件下激发人体内源性保护机制,促进阿片、缓激肽及腺苷等物质的释放,增强线粒体生物合成,抑制疲劳信号转导,进而提升运动表现。④目前缺血预处理提升运动表现的机制研究还不够深入,建议今后进一步探讨其发挥积极效应可能机制的同时,也应关注其是否有负面效应,以期为该方法科学合理地应用提供依据。

Aerobic Degradation Process in Palm Oil Mill— Issues, Challenges and Upsurging Its Efficiency through Bioremediation

Palm oil mill effluent (POME) is liquid waste produced from palm oil extraction process. Discharging it to the river without treatment is violation according to Malaysia Environment of Quality Act (EQA) 1974. In Malaysia, ponding system is a conventional treatment method for POME due to its economical and simple process. The treatment process mainly involves two main treatment phases;anaerobic and aerobic degradation. Anaerobic degradation has a proven track record in reducing pollutant properties in POME up to 85%. The real challenge is to increase the efficiency of aerobic process as the biological oxygen demand (BOD) discharge limit has been further reduced from 100 mg·L-1 to less than 20 mg·L-1. One of economical and feasible approach to increase the efficiency of aerobic phase is via bioremediation. This paper describes the limitation of aerobic degradation in ponding system, besides discussed on the important aspects that need to be optimized for a success implementation of bioremediation and its challenges.

简述物化-生化组合工艺在浆染废水处理中的应用

本工程采用物化手段去除浆染废水中的难溶性有机物、硫化物、悬浮物、总磷等污染物;再采用厌氧水解+好氧去除有机污染物及含氮化合物;最后利用高效沉淀池进一步净化水质,保证出水达标。废水经过处理后,污染物含量大幅度降低,满足地方标准及原处理系统的进水要求,有效缓解并降低了原污水系统的负荷。本文详细给出了相关设计参数,可供同类工程参考。