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A novel online analyzer for accurate and rapid measurement of Volatile fatty acids in anaerobic wastewater treatment

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Journal of Environmental Sciences 2022年第12期34卷 72-82页

作者： Qingshan Lin Yanchao Yuan Feixiang Zan Hui Lu Zongping Wang Gang Guo School of Environmental Science and Engineering Huazhong University of Science and Technology(HUST)Key Laboratory of Water and Wastewater TreatmentMOHURDWuhan 430074China Department of Environmental Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China School of Environmental Science and Engineering Sun Yat-sen UniversityGuangzhou 510275China

Volatile fatty acids(VFAs), which are largely generated during the anaerobic acidification process, are considered to be reliable indicators of the stable process operation. However,the common methods for monitoring VFAs are offline, and they are typically manual requiring time-consuming, costly and complex instruments. This study aims to develop a novel online analyzer for automatic measuring VFAs, which was based on the 5-p H point titration, embedded with a proportional-integral-derivative(PID) feedback control system. The results show that it can achieve accurate and rapid monitoring of VFAs ranging between 0-400 mg/L(<9 min/sample) but simultaneously faces the problems of overtitration and interference of complex characteristics of wastewater. In order to improve its accuracy and stability, the effects of three general coefficients(K_(I),K_(P), and K_(D)) of PID on the titration were investigated, and the optimal values of K_(I), K_(P), and K_(D)were found to be 1.5, 1.0, and-1.0~0.5,respectively. Besides, the initial titration speed was set at 0.06 m L/min, equal to the minimum speed of the peristaltic pump, and the dichotomy approach was integrated into the PID feedback controller. Owing to the above improvements, the relative mean deviation and standard deviation of measuring VFAs in both synthetic and real wastewaters were mostly lower than 5.0% and 5.0 mg/L, proving the online analyzer is rapid, accurate and reliable.

关键词： Volatile fatty acids Online analyzer 5-pH point titration PID feedback control Anaerobic process

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Effects of sludge age on anaerobic acidification of waste activated sludge: Volatile fatty acids production and phosphorus release

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Journal of Environmental Sciences 2021年第7期33卷 11-21页

作者： Sisi Chen Xiaohu Dai Dianhai Yang Bin Dong State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China

Effects of sludge age on Volatile fatty acids (VFAs) production and Phosphorus (P) release during anaerobic acidification of waste activated sludge (WAS) were investigated.Sequencing batch reactors (SBR) fed with simulating domestic sewage were applied to produce WAS of different sludge ages,and batch tests were used for anaerobic acidification.The maximum dissolved total organic carbon,release of PO_(4)^(3+)-P,and accumulation of acetate (C2),propionate (C3),butyrate (C4),and valerate (C5) decreased by 56.2%,55.8%,52.6%,43.7%,82.4%and 84.8%,respectively,as the sludge age of WAS increased from 5 to 40 days.Limited degradation of protein played a dominating role in decreasing DTOC and VFAs production.Moreover,the increase in molecular weight of organics and organic nitrogen content in the supernatant after acidification suggested that the refractory protein in WAS increased as sludge age extended.Although the production of C2,C3,C4,and C5 from WAS decreased as the sludge age increased,the proportions of C2 and C3 in VFAs increased,which might be due to the declined production of C5 from protein and the faded genus Dechlorobacter.Keeping sludge age of WAS at a relatively low level (<10 days) is more appropriate for anaerobic acidification of WAS as internal carbon sources and P resource.

关键词： Sludge age Waste activated sludge Acidification Volatile fatty acids Microbial community

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Enhanced nitrogen removal upon the addition of Volatile fatty acids from activated sludge by combining calcium peroxide and low-thermal pretreatments

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Journal of Environmental Sciences 2021年第10期33卷 145-151页

作者： Jiajun Sun Junxue Song Wei Fang Hongbin Cao Beijing Engineering Research Center of Process Pollution Control Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China China Xiong’an Group Ecological Construction Investment Co.Ltd. Baoding 071700China State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China School of Chemistry and Environmental Engineering China University of Mining and TechnologyBeijing 100083China

This study investigated a combined low-thermal and CaO_(2)pretreatment to enhance the volatile fatty acid(VFA)production from waste activated sludge(WAS).The fermentative product was added to a sequencing batch reactor(SBR)as an external carbon source to enhance nitrogen removal.The results showed that the combined pretreatment improved WAS solubilization,releasing more biodegradable substrates,such as proteins and polysaccharides,from TB-EPS to LB-EPS and S-EPS.The maximum VFA production of 3529±188 mg COD/L was obtained in the combined pretreatment(0.2 g CaO_(2)/g VS+70℃for 60 min),which was 2.1 and 1.4-fold of that obtained from the sole low-thermal pretreatment and the control test,respectively.Consequently,when the fermentative liquid was added as an external denitrification carbon source,the effluent total nitrogen decreased to Class A of the discharge standard for pollutants in rural wastewater treatment plants in most areas of China.

关键词： Waste activated sludge Anaerobic digestion Calcium peroxide Low-thermal pretreatment Volatile fatty acids

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Dietary pectic oligosaccharide supplementation improves rat reproductive performance via regulating intestinal Volatile fatty acids during middle gestation

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Animal Nutrition 2020年第2期6卷 210-216页

作者： Minghui Liu Xiangbing Mao Daiwen Chen Bing Yu Jun He Ping Zheng Jie Yu Junqiu Luo Yuheng Luo Jianping Wang Quyuan Wang Huifen Wang Animal Nutrition Institute Sichuan Agricultural UniversityChengdu611130China Key Laboratory of Animal Disease-Resistance Nutrition Chinese Ministry of EducationChengdu611130China Key Laboratory of Animal Disease-resistant Nutrition and Feed Chinese Ministry of Agriculture and Rural AffairsChengdu611130China Key Laboratory of Animal Disease-resistant Nutrition SichuanChengdu611130China

As a kind of green additive,pectic oligosaccharide(POS) may regulate some physiological functions of animals,such as gut health,antioxidant capacity,immunity and lipid metabolism.This study aimed to identify whether POS administration can improve maternal reproduction,and to determine the possible metabolism.A total of 48 pregnant Wistar rats randomly allotted into 2 groups,and each group was fed a diet supplemented with 0 or 800 mg/kg of POS.Pectic oligosaccharide administration increased rat born number(P volatile fatty acid concentrations of cecal digesta(P volatile fatty acid concentrations in rat gut improving hormone and inflammatory-cytokine productions,and antioxidant capacity.

关键词： Pectic oligosaccharide Rat reproductive performance Volatile fatty acids Hormone and cytokine generations Antioxidant capacity

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A combined pig model to determine the net absorption of Volatile fatty acids in the large intestine under different levels of crude fiber

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动物模型与实验医学(英文) 2023年第4期6卷 375-380页

作者： Shengjun Zhao Liangkang Lv Taotao Wu Zhi Feng Qiang Li Long Lei Zhengya Liu Hui Zhang Ying Ren Hubei Key Laboratory of Animal Nutrition and Feed Science Wuhan Polytechnic UniversityWuhanChina State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural UniversityBeijingChina

Background:This study aimed to develop a combined model to quantify the net absorption of Volatile fatty acids(VFA)in the large intestine(LI)of pigs.Methods:Fifteen female growing pigs(Duroc×Large White×Landrace)were ranked by body weight(30±2.1 kg)on day 0 and assigned to one of three treatments,namely the basal diet containing different crude fiber(CF)levels(LCF:3.0%CF,MCF:4.5%CF,and HCF:6.0%CF).The pigs were implanted with the terminal ileum fistula and the cannulation of the ileal mesenteric vein(IMV),portal vein(PV),and left femoral artery(LFA)from days 6 to 7.[13 C]-Labeled VFA and P-aminohippuric acid were constantly perfused into the terminal ileum fistula and the cannulation of the IMV(day 15),respectively.Blood samples were collected from the PV and the LFA during perfusion(5 h),and LI samples were collected.Results:The net flux of[12 C]-acetic acid in the PV was greater for LCF versus MCF(p=0.045),but no difference was observed in the net flux of[12 C]-propionic acid(p=0.505)and[12 C]-butyric acid(p=0.35)in the PV among treatments.The deposition of[12 C]-acetic acid in the LI was greater for LCF versus MCF(p=0.014),whereas the deposition of[12 C]-propionic acid(p=0.007)and[12 C]-butyric acid(p=0.037)in the LI was greater for LCF versus HCF.Conclusions:In conclusion,this pig model was found conducive to study the net absorption of VFAs in the LI,and LCF had more net absorption of VFAs in the LI than MCF and HCF.

关键词： crude fiber growing pigs large intestine T-type fistula Volatile fatty acids

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Evaluation of in vitro digestibility of Aspergillus oryzae fungal biomass grown on organic residue derived‑VFAs as a promising ruminant feed supplement

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Journal of Animal Science and Biotechnology 2023年第6期14卷 2614-2629页

作者： Clarisse Uwineza Mohammadali Bouzarjomehr Milad Parchami Taner Sar Mohammad J.Taherzadeh Amir Mahboubi Swedish Centre for Resource Recovery University of Boras50190 BorasSweden

Background As demand for high quality animal feed continues to raise,it becomes increasingly important to mini-mize the environmental impact of feed production.An appealing sustainable approach to provide feed fractions is to use organic residues from agro-food industry.In this regard,Volatile fatty acids(VFAs)such as acetic,propionic and butyric acids,derived from bioconversion of organic residues can be used as precursors for production of micro-bial protein with ruminant feed inclusion potential.This study aims to investigate the in vitro digestibility of the Asper-gillus oryzae edible fungal biomass cultivated on VFAs-derived from anaerobic digestion of residues.The produced fungal protein biomass,along with hay clover silage and rapeseed meal were subjected to various in vitro assays using two-stage Tilley and Terry(TT),gas,and bag methods to evaluate and compare its digestibility for application in ruminant feed.Results The produced fungal biomass contained a higher crude protein(CP)(41%–49%)and rather similar neutral detergent fiber(NDF)(41%–56%)compared to rapeseed meal.The rumen in vitro dry matter digestibility(IVDMD)of the fungal biomass in the TT method ranged from 82%to 88%(statistically similar to that of the gas method(72%to 85%)).The IVDMD of fungal biomass were up to 26%and 40%greater than that of hay clover silage and rapeseed meal,respectively.The type of substrate and bag method had pronounced effect on the fermentation products(ammonium-N(NH4+-N),total gas and VFAs).Fungal biomass digestion resulted in the highest release of NH4+-N(340–540 mg/L)and the ratio of acetate to propionate ratio(3.5)among subjected substrates.Conclusion The results indicate that gas method can be used as a reliable predictor for IVDMD as well as fermenta-tion products.Furthermore,the high IVDMD and fermentation product observed for Aspergillus oryzae fungal biomass digestion,suggest that the supplementation of fungal biomass will contribute to improving the rumen digestion by providing necessary nitrogen and energy

关键词： Aspergillus oryzae Fungal biomass In vitro dry matter digestibility Ruminant feed Volatile fatty acids

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Machine learning enabled prediction and process optimization of VFA production from riboflavin-mediated sludge fermentation

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Frontiers of Environmental Science & Engineering 2023年第11期17卷 181-193页

作者： Weishuai Li Jingang Huang Zhuoer Shi Wei Han Ting Lü Yuanyuan Lin Jianfang Meng Xiaobing Xu Pingzhi Hou College of Materials and Environmental Engineering Hangzhou Dianzi UniversityHangzhou 310018China China-Austria Belt and Road Joint Laboratory on Artificial Intelligence and Advanced Manufacturing Hangzhou Dianzi UniversityHangzhou 310018China Zhejiang Province Environmental Engineering Co.Ltd. Hangzhou 310012China M-U-T Maschinen-Umwelttechnik-Transportanlagen GmbH Stockerau 2000Austria

Riboflavin is a redox mediator that promotes Volatile fatty acids(VFAs)production from waste activated sludge(WAS)and is a promising method for WAS reuse.However,time-and labor-consuming experiments challenge obtaining optimal operating conditions for maximal VFA production.In this study,three machine learning(ML)models were developed to predict the VFAs production from riboflavin-mediated WAS fermentation systems.Among the three tested ML algorithms,eXtreme Gradient Boosting(XGBoost)presented the best prediction performance and excellent generalization ability,with the highest testing coefficient of determination(R^(2)of 0.93)and lowest root mean square error(RMSE of 0.070).Feature importance analysis and their interactions using the Shepley Additive Explanations(SHAP)method indicated that pH and soluble protein were the top two input features for the modeling.The intrinsic correlations between input features and microbial communities corroborated this deduction.On the optimized ML model,genetic algorithm(GA)and particle swarm optimization(PSO)solved the optimal solution of VFA output,predicting the maximum VFA output as 650 mg COD/g VSS.This study provided a data-driven approach to predict and optimize VFA production from riboflavin-mediated WAS fermentation.

关键词： Machine learning Volatile fatty acids Riboflavin Waste activated sludge eXtreme Gradient Boosting

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Potassium ferrate pretreatment promotes short chain fatty acids yield and antibiotics reduction in acidogenic fermentation of sewage sludge

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Journal of Environmental Sciences 2022年第10期34卷 41-52页

作者： Zihao Qiao Suyun Xu Wanqiu Zhang Shuyin Shi Wei Zhang Hongbo Liu School of Environment and Architecture University of Shanghai for Science and TechnologyShanghai 200093China Centillion Resource Recycling(Wuxi)Co.Ltd. Wuxi 214000China

During the acidogenic fermentation converting waste activated sludge (WAS) into shortchain fatty acids (SCFA), hydrolysis of complex organic polymers is a limiting step and the transformation of harmful substances (such as antibiotics) during acidogenic fermentation is unknown. In this study, potassium ferrate (KFeO) oxidation was used as a pretreatment strategy for WAS acidogenic fermentation to increase the hydrolysis of sludge and destruct the harmful antibiotics. Pretreatment with KFeOcan effectively increase the SCFA production during acidogenic fermentation and change the distribution of SCFA components.With the dosage of 0.2 g/g TS, the maximum SCFA yield was 4823 mg COD/L, which is 28.3times that of the control group;acetic acid accounts for more than 90% of the total SCFA. The higher dosage (0.5 g/g TS) can further increase the proportion of acetic acid, but inhibit the overall performance of SCFA production. Apart from the promotion of hydrolysis and acidogenesis, KFeOpretreatment can also simultaneously oxidizes and degrades part of the antibiotics in the sludge. When the dosage is 0.5 g/g TS, the degradation efficacy of antibiotics is the most significant, and the contents of ofloxacin, azithromycin, and tetracycline in the sludge are reduced by 69%, 42%, and 50%, respectively. In addition, KFeOpretreatment can also promote the release of antibiotics from sludge flocs, which is conducive to the simultaneous degradation of antibiotics in the subsequent biological treatment process.

关键词： Acidogenic fermentation Antibiotics Potassium ferrate Oxidation pretreatment Sewage sludge Volatile fatty acids

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Large intestinal dynamics differ between fowl and swine:Anatomical modifications,microbial collaboration,and digestive advantages from fibrolytic enzymes

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Animal Nutrition 2022年第4期11卷 160-170页

作者： Edwin T.Moran Jr. Michael R.Bedford Poultry Science Department Auburn UniversityAL 36830-5416USA AB Vista Woodstock CourtBlenheim RoadMarlboroughWiltshire SN84ANUK

The large intestinal systems of fowl and swine recover nutrients from ileal indigesta by a strategically different manner.Indigesta with fowl enter a short colon where retro-peristalsis using urine from the urodeum carries small particulates and solutes into both ceca while coarse materials collect in the cloaca.Fowl repetitively add fine and soluble materials into both ceca to continue fermentation until complexity of the remainder exceeds microbial action,then contents apart from faeces are entirely evacuated.Indigesta with swine initially enter a short cecum followed by a lengthy progression through to the rectal ampulla.Wall out-pocketings of circular muscle or haustrae occur throughout the length of the pig's cecum and helicoidal colon.Each pocket carries contents acquired earlier in the cecum.Motility collects fines and solutes into haustrae during their progression through the colon whereas coarse particulates assemble in the core.Haustrae contents continually ferment during movement to the distal colon with resulting Volatile fatty acids(VFA)and electrolytes being absorbed.Mucin loosely covers the lumen surface in caeca as well as helicoidal colon that may capture microbes from active intestinal contents as well as release others to sustain fermentation.The microbial community continually modifies to accommodate fibre complexity as encountered.Resistant starches(RS)and simple oligosaccharides rapidly ferment to yield VFA while encouraging butyric acid in the cecum and anterior colon,whereas non-starch polysaccharides(NSP)complexity requires extended durations through the remaining colon that enhance acetic acid.Residual fibre eventually results in undue complexity for fermentation and consolidates at termination of the colon.These compact pellets are placed on core contents to form faeces having a nodular surface.Acetic,propionic,and butyric acids represent the bulk of VFA and are derived from non-digestible carbohydrates.Fibrolytic enzymes,when supplemented to feed,may increase the proportion of oligosac

关键词： Butyric acid Endogenous protein Intestinal microbes Large intestine Volatile fatty acids Xylanase

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Inhibition character of crotonaldehyde manufacture wastewater on biological acidification

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Frontiers of Environmental Science & Engineering 2021年第6期15卷 293-302页

作者： Tao Liu Yudong Song Zhiqiang Shen Yuexi Zhou State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Research Center of Environmental Pollution Control Engineering Technology Chinese Research Academy of Environmental SciencesBeijing 100012China School of Environment Tsinghua UniversityBeijing 100084China

This work aims to investigate the inhibitory effect of crotonaldehyde manufacture wastewater(CMW)on biological acidification.To reveal the inhibitory effect of wastewater to the anaerobic granular sludge(AnGS),variations of the specific acidogenic activity(SAA)and activities of key enzymes were investigated.The results indicated that the dosage of CMW causing a 50%effect concentration(EC50)on the activity of total Volatile fatty acids(TVFA)production was 380 mg COD/g VSS.The inhibitory effect of individual toxicants in CMW on the activity of TVFA production were in the order of crotonaldehyde>ethyl sorbate>(E,E)-2,4-hexadienal,and their inhibitory degrees on individual VFA productions were acetic acid(Ac)>n-butyric acid(n-Bu),which could correspond to the variations in the activities of acetate kinase(AK)and butyrate kinase(BK).Furthermore,the combined effect of three toxicants on the activity of TVFA production was significantly higher than that of any individual toxicant,and the contribution of the relative toxicity to CMW was 77.27%.Additionally,the biodegradation products of the main toxicants indicated that the removal of crotonaldehyde and(E,E)-2,4-hexadienal was primarily due to the hydrogenation of alkene and aldehyde and the oxidation of aldehyde.Nevertheless,the removal of ethyl sorbate was primarily based on adsorption.In conclusion,biological acidification has a limited ability to treatment CMW,therefore,a further pretreatment technology should be used to remove the main toxicant of wastewater.

关键词： Crotonaldehyde manufacture wastewater Biological acidification Volatile fatty acids Inhibition Toxic units

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