Publications by authors named "Zonglian She"

75 Publications

Effect of aerobic/anoxic duration on the performance, microbial activity and microbial community of sequencing batch biofilm reactor treating synthetic mariculture wastewater.

Bioresour Technol 2021 Apr 22;333:125198. Epub 2021 Apr 22.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.

The effect of aerobic/anoxic duration on the performance, microbial community and enzymatic activity of sequencing batch biofilm reactor (SBBR) were investigated in treating mariculture wastewater. The microbial oxygen uptake rate and nitrifying rate gradually decreased with the aerobic/anoxic duration from 120/210 to 30/300 min, whereas the nitrite reducing rate and nitrate reducing rate had the opposite results. The activities of dehydrogenase, ammonia monooxygenase and nitrite oxidoreductase gradually decreased with the aerobic/anoxic duration from 120/210 to 30/300 min, but the activities of nitrate reductase and nitrite reductase had a gradual increment. The microbial nitrogen removal rates had similar changing trends to their corresponding enzymatic activities at different aerobic/anoxic duration. The variation of aerobic/anoxic duration obviously affected the microbial richness and diversity of SBBR. The co-occurrence, keystone taxa and significant difference of microbial community had some changes with the aerobic/anoxic duration from 120/210 to 30/300 min.
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http://dx.doi.org/10.1016/j.biortech.2021.125198DOI Listing
April 2021

Enhancing microalgae growth and product accumulation with carbon source regulation: New perspective for the coordination between photosynthesis and aerobic respiration.

Chemosphere 2021 Mar 31;278:130435. Epub 2021 Mar 31.

College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.

The coordination between photosynthesis and aerobic respiration under mixotrophic cultivation can make a difference to the growth and biochemical composition of microalgae. However, the response of carbon metabolism to carbon source composition under mixotrophic microalgae cultivation has not been well studied. In this study, the synergistic effects of inorganic carbon (IC) and organic carbon (OC) supply on the growth and carbon metabolism of Chlorella vulgaris under mixotrophic cultivation were investigated. The increase of the proportion of HCO had a positive effect on the expression of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), which promoted the biomass production and carbon fixing. The activity of citrate synthase was attenuated with the increase of IC/OC ratio, indicating that the energy needed for the biomass production in groups with high IC/OC ratio was contributed by photoreaction. Biochemical analysis showed that CO was more efficient than HCO for carbohydrate and lipid accumulation of Chlorella vulgaris, and the highest amount of carbohydrate (30.2%) and lipid (35.8%) was recorded with the combined use of CO and glucose. The results could provide a new perspective on carbon metabolism and enzyme regulation in mixotrophic microalgae cultivation.
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http://dx.doi.org/10.1016/j.chemosphere.2021.130435DOI Listing
March 2021

Effects of salinity on pollutant removal and bacterial community in a partially saturated vertical flow constructed wetland.

Bioresour Technol 2021 Jun 23;329:124890. Epub 2021 Feb 23.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, 266100 Qingdao, China; College of Environmental Science and Engineering, Ocean University of China, 266100 Qingdao, China.

This study investigated the influence of salinity on pollutant removal and bacterial community within a partially saturated vertical flow constructed wetland (PS-VFCW). High removal rates of NH-N (88.29 ± 4.97-100 ± 0%), total inorganic nitrogen (TIN) (50.00 ± 7.21-62.81 ± 7.21%) and COD (91.08 ± 2.66-100 ± 0%) were achieved at 0.4-2.4% salinity levels. The removal of ammonia, TIN and organic matter occurred mainly in unsaturated zone. Salt-adaptable microbes became the dominant bacteria with salinity elevated. The proportion of ammonia-oxidizing bacteria (AOB) in the 0-5 cm depth layer (unsaturated zone) decreased obviously as the salinity increased to 2.4%. Nitrite-oxidizing bacteria (NOB) in the 0-5 cm depth layer showed a decreasing trend with elevated salinity. Denitrifying bacteria (DNB) in the 0-5 cm depth layer maintained high abundance (27.70-53.60%) at 0.4-2.4% salinity levels. At 2.4% salinity, AOB, NOB and DNB were observed in the unsaturated zones and saturated zones, and showed higher abundance in the unsaturated zone.
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http://dx.doi.org/10.1016/j.biortech.2021.124890DOI Listing
June 2021

Integrating acidogenic fermentation and microalgae cultivation of bacterial-algal coupling system for mariculture wastewater treatment.

Bioresour Technol 2021 Jan 29;320(Pt A):124335. Epub 2020 Oct 29.

Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.

In this study, Bacterial-Algal Coupling System, a method integrated acidogenic fermentation (AF) and microalgae cultivation, was applied to the mariculture wastewater (MW) treatment. The MW was acidogenic fermented at different initial pH (4.0-10.0), and different dilution rate (5%-20%) of AF effluent was used for Chlorella vulgaris cultivation. The results showed that the maximum biomass production (5.6 g/L) of microalgae was obtained with 10% AF effluent. Ammonium, phosphate and volatile fatty acids could be metabolized by microalgae. More specifically, acetic acid and propionic acid were utilized prior to butyric acid and valeric acid. To better understand the synergy of heterotrophic metabolism and photosynthesis, the activities of Rubisco and citrate synthase were revealed to provide additional insight for nutrients recovery from MW by mixotrophic cultivation of microalgae.
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http://dx.doi.org/10.1016/j.biortech.2020.124335DOI Listing
January 2021

Effect of salinity and pH on dark fermentation with thermophilic bacteria pretreated swine wastewater.

J Environ Manage 2020 Oct 4;271:111023. Epub 2020 Jul 4.

College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.

The utilization of swine wastewater is affected by salinity and pH owing to the extensive use with seawater instead of domestic water as swine farm flushing water in coastal city. Therefore, swine wastewater pretreated with thermophilic bacteria was used as fermentation substrate in this work, the effects of salinity and pH on dark fermentation under mesophilic condition were investigated. The research showed that 1.5% salinity and pH 6.0 were the optimal conditions for hydrogen production with swine wastewater. The activity of hydrogenogen was inhibited at 3.5% salinity and pH 5.0. Soluble organic matter in substrate was accumulated under high salinity and alkaline conditions. The utilization of carbohydrate during dark fermentation was up to 61.1% at 1.5% salinity and 51.5% at pH 9.0. Enhancing of salinity and pH had an advantage in accumulation of total soluble metabolites. Acetate was the main metabolite during dark fermentation, and 1.5% salinity contributed to the formation of butyrate.
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http://dx.doi.org/10.1016/j.jenvman.2020.111023DOI Listing
October 2020

Performance and bacterial communities in unsaturated and saturated zones of a vertical-flow constructed wetland with continuous-feed.

Bioresour Technol 2020 Nov 16;315:123859. Epub 2020 Jul 16.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China. 266100 Qingdao, China; College of Environmental Science and Engineering, Ocean University of China. 266100 Qingdao, China.

In this study, a partially-saturated vertical-flow constructed wetland (VFCW) with continuous-feed was operated to investigate nutrients transformation and possible pathways in unsaturated and saturated zones. Effect of temperature on nutrients removal and microbial community was also evaluated. The variation of temperature barely affected removal of NH-N and COD, achieving removal efficiencies of 99.5-100.0% and 96.8-100.0% at effluent temperature of 14.9-27.7 °C. The removal of COD, NH-N, total inorganic nitrogen (TIN) and total phosphorus mainly occurred in unsaturated zone, achieving much higher removal rates than saturated zone. Nitrification process in the VFCW was associated with autotrophic/heterotrophic ammonia oxidizing bacteria and nitrite oxidizing bacteria. Denitrification process relied on both autotrophic and heterotrophic denitrifiers. Anaerobic ammonium oxidizing bacteria was also detected, contributing to TIN removal. All of the groups for nutrients removal exhibited higher abundance in unsaturated zone. Diverse pathways co-existed for nitrogen removal, while the main metabolic pathways were different along the depth.
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http://dx.doi.org/10.1016/j.biortech.2020.123859DOI Listing
November 2020

Comparison of the effects of salinity on microbial community structures and functions in sequencing batch reactors with and without carriers.

Bioprocess Biosyst Eng 2020 Dec 13;43(12):2175-2188. Epub 2020 Jul 13.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.

This study investigated and compared the microbial communities between a sequencing batch reactor (SBR) without carriers and a hybrid SBR with addition of carriers for the treatment of saline wastewater. The two systems were operated over 292 days with alternating aerobic/anoxic mode (temperature: 28℃, salinity: 0.0-3.0%). High removal efficiency of chemical oxygen demand (COD) and total inorganic nitrogen (TIN) was achieved in both the SBR (above 86.7 and 95.4% respectively) and hybrid SBR (above 84.4 and 94.0%) at 0.0-2.5% salinity. Further increasing salinity to 3.0% decreased TIN removal efficiency to 78.4% in the hybrid SBR. Steep decline of biodiversity and relative abundance of ammonia-oxidizing bacteria (AOB) contributed to the worse performance. More genera related to sulfide-oxidizing and sulfate-reducing bacteria were detected in the hybrid SBR than the SBR at 3.0% salinity. The abundance of halotolerant bacteria increased with the salinity increase for both reactors, summing up to 25.5% in the suspended sludge (S-sludge) from the SBR, 28.9 and 22.9% in the S-sludge and biofilm taken from the hybrid SBR, respectively. Nitrification and denitrification via nitrate was the main nitrogen removal pathway in the SBR and hybrid SBR at 0.0 and 0.5% salinity, while partial nitrification and denitrification via nitrite became the key process for nitrogen removal in the two reactors when the salinity was increased to 1.0-3.0%. Higher abundance of anaerobic ammonium-oxidizing (ANAMMOX) and sulfide-oxidizing autotrophic denitrification (SOAD) bacteria were found in the hybrid SBR at 3.0% salinity.
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http://dx.doi.org/10.1007/s00449-020-02403-8DOI Listing
December 2020

Elucidating temperature on mixotrophic cultivation of a Chlorella vulgaris strain: Different carbon source application and enzyme activity revelation.

Bioresour Technol 2020 Oct 21;314:123721. Epub 2020 Jun 21.

Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.

With depletion of fossil fuel, microalgae is considered as a promising substitute due to high growth rate, efficient cost and high biofuels content. This study investigated the effect of temperature on mixotrophic cultivation of Chlorella vulgaris. In addition, the combination carbon source of inorganic (HCO or CO) and organic (glucose or acetate) for microalgae cultivation was evaluated to obtain the optimum carbon source for mixotrophic cultivation. The results showed that the optimum temperature of microalgae cultivation was at the range of 15-20 °C. The activity of Rubisco was obviously inhibited at the temperature of 30 °C, however, citrate synthase was not susceptible to the increasing temperature. COD removal efficiency was all higher than 64.0%. Low temperature was benefit for protein formation, and the lipid accumulation occurred at high temperature. The results provide a fresh perspective between enzyme activity and temperature variation for product accumulation of microalgae.
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http://dx.doi.org/10.1016/j.biortech.2020.123721DOI Listing
October 2020

Denitrification performance evaluation and kinetics analysis with mariculture solid wastes (MSW) derived carbon source in marine recirculating aquaculture systems (RAS).

Bioresour Technol 2020 Oct 11;313:123649. Epub 2020 Jun 11.

College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.

Biological denitrification using mariculture solid wastes (MSW) carbon source is a promising solution for removing nitrate (NO-N) and disposing MSW in marine recirculating aquaculture systems (RAS). To enhance denitrification performance, heating (HT), rhamnolipid (RL), alkali (AL), thermophilic bacteria (TB) pre-treated MSW acidogenic fermentation effluents were prepared as carbon sources. Profiles of soluble organics in four types of fermentation effluents were first evaluated. The highest volatile fatty acids (VFAs) yield (52.1%) was obtained from TB treated MSW after acidification. RL and TB treated MSW acidogenic fermentation effluents showed high NO-N removal efficiency (NRE) (around 97%). Acidogenic fermentation effluent from TB treated MSW presented a high biodegradability, with the minimum effluent chemical oxygen demand (COD) amount (35 mg/L). Denitrification kinetics parameters were also analyzed; high fraction (74.5%) of the most readily biodegradable organics (S) demonstrated that TB treated MSW acidogenic fermentation effluent is a high-quality carbon source for enhancing denitrification.
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http://dx.doi.org/10.1016/j.biortech.2020.123649DOI Listing
October 2020

Transcriptomics of Planococcus kocurii O516 reveals the degrading metabolism of sulfamethoxazole in marine aquaculture wastewater.

Environ Pollut 2020 Oct 4;265(Pt B):114939. Epub 2020 Jun 4.

Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering (MEGE), College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China; Key Laboratory of Marine Environment and Ecology (Ocean University of China), Ministry of Education, Qingdao, 266100, China.

Environmental threat induced by residual antibiotics in marine aquaculture wastewater is an urgent problem to be solved. In this study, one sulfamethoxazole (SMX)-degrading bacterium, Planococcus kocurii O516 was isolated from high SMX marine aquafarm. The isolate was able to consume more than 60% of SMX with the initial concentration of 10 mg L within 72 h. Transcriptome analysis found great gene expression differences in the strains with or without SMX dosage. Three putatively differentially expressed proteins, namely AbrB/MazE/SpoVT family DNA-binding domain-containing protein, pantoate-beta-alanine ligase and MerR family transcriptional regulator, were annotated in detail. They were inferred to trigger the strain's response to SMX stress. Reverse transcription-quantitative PCR (RT-qPCR) analysis of four significantly different expressed genes accorded well with expression changes revealed by transcriptomics and confirmed the validity of transcriptome analysis. According to functional annotations of the proteins obtained by transcriptome sequencing and structural analysis of the intermediate metabolites by GC-MS, a possible SMX degradation pathway was reasonably proposed. SMX was first decomposed into sulfonamide and 5-methylisoxazole. The sulfonamide was then hydroxylated to form 4-(hydroxyamino) benzenesulfonamide. Subsequently, the sulfamic acid was detached, and 4-(hydroxyamino) phenol was formed. Finally, 4-aminophenol was generated from dehydroxylated of 4-(hydroxyamino) phenol. In sum, transcriptome analysis of the P. kocurii in response to SMX stress benefits to revealing the degradation pathway of SMX and will provide theoretical feasibility for the application of microbial method to treat the SMX-contaminated aquaculture wastewater.
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http://dx.doi.org/10.1016/j.envpol.2020.114939DOI Listing
October 2020

Elucidating salinity adaptation and shock loading on denitrification performance: Focusing on microbial community shift and carbon source evaluation.

Bioresour Technol 2020 Feb 22;305:123030. Epub 2020 Feb 22.

Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Science, Qingdao 266071, China.

To understand the denitrification efficiency and microbial community shift with increasing salinity in salinity adaptation and shock loading process, nitrate (NO-N), nitrite (NO-N) and chemical oxygen demand (COD) removal efficiencies were monitored feeding acetate and primary sludge fermentation liquid. During adaptation process, salinity had little effect on NO-N removal efficiency (>99.0%) with acetate-fed, while for fermentation liquid-fed, it decreased to around 97% at high salinity (>2.5%). Effluent NO-N was lower than 0.1 mg/L, though obvious fluctuation of NO-N was observed with fermentation liquid-fed when salinity change. During shock loading process, denitrification process all had slight decrease when the salinity abruptly increased to 5.0%. Traditional denitrifier of Thauera was the dominant genus, and a specialized microbial community of Azoarcus in salinity adaptation and Paracoccus in shock loading for denitrification showed high salinity tolerant. Meanwhile, microbial diversity was enriched with fermentation liquid-fed at high salinity condition.
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http://dx.doi.org/10.1016/j.biortech.2020.123030DOI Listing
February 2020

Single and combined effects of divalent copper and hexavalent chromium on the performance, microbial community and enzymatic activity of sequencing batch reactor.

Sci Total Environ 2020 Jun 27;719:137289. Epub 2020 Feb 27.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China. Electronic address:

Divalent copper (Cu) and hexavalent chromium (Cr) are often encountered in industrial wastewater and municipal wastewater, the effect of combined Cu and Cr on biological wastewater treatment systems has cause wide concern. In the present research, the performance, microbial community and enzymatic activity of sequencing batch reactors (SBRs) were compared under the single and combined Cu at 20 mg/L and Cr at 10 mg/L. The chemical oxygen demand (COD) and ammonia nitrogen (NH-N) removal efficiencies under the combined Cu and Cr were less than those under the single Cu and Cr. The combined Cu and Cr displayed more inhibition effects on the oxygen uptake rate, nitrification rate and denitrification rate of activated sludge than the single Cu and Cr. The inhibitory effects of the combined Cu and Cr on the activities of dehydrogenase, ammonia monooxygenase, nitrite oxidoreductase, nitrite reductase and nitrate reductase showed significant increases by comparison with the single Cr. However, the combined Cu and Cr had a little more inhibitory effects on the enzymatic activities than the single Cu. The microbial richness and diversity displayed some obvious changes under the single and combined Cu and Cr by comparison the absence of Cu and Cr. The relative abundances of nitrifying genera (e.g. Nitrosomonas and Nitrospira) under the combined Cu and Cr was less than those under the single Cu and Cr. These findings will be helpful to better understand the combined effects of multiple heavy metals on biological wastewater treatment systems.
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http://dx.doi.org/10.1016/j.scitotenv.2020.137289DOI Listing
June 2020

Heterotrophic denitrification strategy for marine recirculating aquaculture wastewater treatment using mariculture solid wastes fermentation liquid as carbon source: Optimization of COD/NO-N ratio and hydraulic retention time.

Bioresour Technol 2020 May 11;304:122982. Epub 2020 Feb 11.

College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.

Heterotrophic denitrification using mariculture solid wastes (MSW) fermentation liquid as carbon source is an economically and environmentally sustainable strategy for NO-N removal in marine recycling aquaculture systems (RAS). The optimization of COD/NO-N ratio (C/N) and hydraulic retention times (HRT) with respect to MSW fermentation liquid driven denitrification for marine RAS wastewater treatment was investigated. The optimum C/N of 8 and HRT of 6 h for heterotrophic denitrification was obtained with NO-N removal efficiency of 97.8% and 94.2%, respectively. Using MSW fermentation liquid as carbon source, the utilization of VFAs was more effective than that of carbohydrates and proteins, and effluent COD concentration decreased with an increment in HRT from 4 to 8 h. The results of high-throughput sequencing analysis showed microbial communities were enriched selectively in the reactors by optimizing C/N and HRT, which obviously enhanced the nitrogen removal in respect to MSW fermentation liquid driven denitrification.
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http://dx.doi.org/10.1016/j.biortech.2020.122982DOI Listing
May 2020

Insights into the effects of single and combined divalent copper and humic acid on the performance, microbial community and enzymatic activity of activated sludge from sequencing batch reactor.

Chemosphere 2020 Jun 12;249:126165. Epub 2020 Feb 12.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China. Electronic address:

The performance, microbial community and enzymatic activity of activated sludge from four identical sequencing batch reactors (SBRs) were compared by treating synthetic wastewater under the single and combined divalent copper (Cu) at 20 mg/L and humic acid (HA) at 20 mg/L. Compared with the absence of Cu and HA, the single HA slightly enhanced the oxygen uptake rate (OUR), the nitrification and denitrification rates and the activities of dehydrogenase, nitrifying enzymes and denitrifying enzymes, whereas the single Cu had the opposite results. The combined Cu and HA inhibited the OUR, nitrogen removal rate and enzymatic activity of activated sludge almost the same as the single Cu. The single HA had no obvious effect on the balance between the microbial oxidative stress and antioxidant activity. However, the variations of microbial reactive oxygen species production, peroxidase activity, catalase activity, superoxide dismutase activity, and lactate dehydrogenase release demonstrated that the combined Cu and HA and single Cu produced obvious toxicity to microorganisms in activated sludge. The microbial richness and diversity had some obvious changes under the single and combined Cu and HA. The relative abundances of Nitrosomonas, Nitrospira and some denitrifying genera (e.g. Zoogloea, Dokdonella, Denitratisoma, Flavobacterium and Thermomonas) under the combined Cu and HA were less than those under the single Cu.
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http://dx.doi.org/10.1016/j.chemosphere.2020.126165DOI Listing
June 2020

Effects of transient 3-chloroaniline shock loading on the performance, microbial community and enzymatic activity of sequencing batch reactor.

J Environ Manage 2020 Mar 7;258:110017. Epub 2020 Jan 7.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Qingdao, 266100, China.

Chloroanilines from industrial wastewater can produce adverse effects on biological wastewater treatment systems due to their potential biotoxicity. The performance, nitrogen removal rate, microbial community and enzymatic activity of a sequencing batch reactor (SBR) were evaluated under transient 3-chloroaniline shock loading. After 40 mg/L 3-chloroaniline shock loading of 24 h on day 9, the chemical oxygen demand (COD) removal efficiency decreased from 90.71% on day 8 to 80.57% on day 11, and the NH-N removal efficiency reduced from 98.96% on day 8 to 35.51% on day 12. Subsequently, the COD and NH-N removal efficiencies gradually recovered to normal value. Compared with the absence of 3-chloroaniline shock loading, the ammonia-oxidizing rate (SAOR), nitrite-oxidizing rate (SNOR), nitrite-reducing rate (SNIRR) and nitrate-reducing rate (SNRR) decreased by 66.19%, 14.49%, 16.20% and 49.38% on day 11, respectively, and then they gradually recovered to normal value. The SAOR, SNOR, SNIRR and SNRR displayed the similar varying trends to the activities of ammonia monooxygenase, nitrite oxidoreductase, nitrite reductase and nitrate reductase, respectively. The appearance of 3-chloroaniline promoted the microbial reactive oxygen species production and lactate dehydrogenase release. The transient 3-chloroaniline shock loading distinctly impacted the microbial richness and diversity. The present research results can provide theoretical basis and technical support for evaluating the effects of transient 3-chloroaniline shock on biological wastewater treatment systems, which is beneficial to take reasonable preventable measures to decrease the adverse effects on the bioreactor performance.
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http://dx.doi.org/10.1016/j.jenvman.2019.110017DOI Listing
March 2020

Enhancing swine wastewater hydrolysis with thermophilic bacteria and assisted pretreatments.

Water Environ Res 2020 Jul 27;92(7):954-958. Epub 2020 Jan 27.

College of Environmental Science and Engineering, Ocean University of China, Qingdao, China.

Slow degradation rate of swine wastewater, which is mainly caused by particulate and refractory organic matters, is the main drawback of anaerobic digestion. Therefore, it is necessary to improve the hydrolysis of swine wastewater. In this study, different pretreatments were used to hydrolyze swine wastewater, including thermophilic bacteria (TB), alkali, acid, ultrasound (UL), and ultrasonic-combined thermophilic bacteria (UL-TB) pretreatment. The hydrolysis effect was investigated by analyzing the changes of pretreated soluble chemical oxygen demand (SCOD), soluble protein, and carbohydrate. The experimental results showed that effect of different pretreatments on swine wastewater hydrolysis had the following order: TB = alkali>UL-TB > UL>acid. Alkali pretreatment was effective for the release of protein from swine wastewater, and TB pretreatment was advantageous for carbohydrate release during hydrolysis. The results could provide valuable information for the disposition of swine wastewater as well as the application of TB-related pretreatments. PRACTITIONER POINTS: TB and alkali pretreatment exhibited the highest hydrolysis ability. The release of carbohydrate by TB was higher than other pretreatments. Ultrasonic assistance generated inhibition on the hydrolysis of TB.
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http://dx.doi.org/10.1002/wer.1295DOI Listing
July 2020

Effect of magnetic powder on denitrification using the sludge alkaline fermentation liquid as a carbon source.

Environ Sci Pollut Res Int 2020 Mar 26;27(7):7712-7719. Epub 2019 Dec 26.

College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.

This work evaluates the impact of the different concentrations of FeO on nitrate removal and organic matters utilization in the sequencing batch reactors (SBRs) using the sludge alkaline digestion supernatant as external sludge carbon source. Results indicated that the optimal concentration of FeO was 1 g/L for enhancing denitrification with NO-N removal efficiency of 93.13% (up to a 11.93% increase) and without NO-N accumulation after 18 days. The changes of soluble chemical oxygen demand (SCOD), protein, and carbohydrate during denitrification process were analyzed to gauge the utilization of sludge fermentation products by denitrifiers. The SCOD was consumed for organisms involved in NO-N removal and the FeO could promote the utilization of carbohydrate better than protein by denitrifiers during denitrification process. Denitrification rate (V) and the nitrate-to-nitrite transformation ratio (NTR), as the kinetics parameters, were also investigated in different concentrations of FeO.
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http://dx.doi.org/10.1007/s11356-019-07461-4DOI Listing
March 2020

Comparation of thermophilic bacteria (TB) pretreated primary and secondary waste sludge carbon sources on denitrification performance at different HRTs.

Bioresour Technol 2020 Feb 18;297:122438. Epub 2019 Nov 18.

College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.

In this study, thermophilic bacteria pretreated primary and secondary waste sludge hydrolysis and acidification liquid were used as denitrification carbon sources at different HRTs (hydraulic retention time). The NO-N removal rate of 99.3%, 99.0%, 99.9% and 99.2% was achieved at the optimal HRT of 8, 8, 4 and 6 h, respectively. Meanwhile, the utilization of COD (Chemical oxygen demand), proteins, carbohydrates, and VFAs (Volatile fatty acids) in carbon source during denitrification was also investigated. High-throughput sequencing technology showed that the microbial community changed with the different sludge carbon sources. And the dominant genus in both reactors was Thauera, which played a key role in denitrification.
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http://dx.doi.org/10.1016/j.biortech.2019.122438DOI Listing
February 2020

Effect of alkyl polyglycosides on the performance of thermophilic bacteria pretreatment for saline waste sludge hydrolysis.

Bioresour Technol 2020 Jan 21;296:122307. Epub 2019 Oct 21.

College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.

In this study, alkyl polyglycosides (APG) was used to further accelerate the hydrolysis of saline waste sludge with thermophilic bacteria (TB) pretreatment. In the presence of 0.4 g/g TSS APG, the concentrations of soluble chemical oxygen demand (SCOD), soluble carbohydrate and soluble protein in dissolved organic matters (DOM) were 0.4, 2.4 and 1.3 times of that without APG addition, respectively. Excitation emission matrix (EEM) fluorescence spectroscopy revealed that the addition of APG led to the increase of soluble microbial materials and the decrease of fulvic acid-like substances in DOM, which was beneficial for the subsequent process of anaerobic digestion. Using APG promoted the releasing of enzymes trapped in saline waste sludge and improved the activity of enzymes during hydrolysis. The activities of α-glucosidase and protease increased by 8.8% and 21.3% respectively in the presence of 0.4 g/g TSS APG comparing no APG addition.
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http://dx.doi.org/10.1016/j.biortech.2019.122307DOI Listing
January 2020

Effects of chemical oxygen demand concentration, pH and operation cycle on polyhydroxyalkanoates synthesis with waste sludge.

Environ Technol 2021 May 7;42(12):1922-1929. Epub 2019 Nov 7.

College of Environmental Science and Engineering, Ocean University of China, Qingdao, People's Republic of China.

To reduce the cost of polyhydroxyalkanoate (PHA) production and dispose the amount of waste sludge simultaneously, chemical oxygen demand (COD) concentration, pH and operation cycle were investigated to find the optimal PHA synthesis conditions with waste sludge in this study. The maximum PHA content (31.3% of the cell dry weight (CDW)), as well as the highest PHA conversion rate (0.30 mg COD/mg COD) and PHA-specific synthesis rate (6.12 mg COD/mg CDW·h), was achieved with initial COD concentration, pH value and operation cycle: 6000 mg/L, 8.5 and 24 h. In order to further investigate the process of PHA synthesis, COD removal rate and CDW were also introduced. This study could provide valuable information for increasing the production of PHA with waste sludge.
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http://dx.doi.org/10.1080/09593330.2019.1683615DOI Listing
May 2021

Long-term effect of different Cu(II) concentrations on the performance, microbial enzymatic activity and microbial community of sequencing batch reactor.

Environ Pollut 2019 Dec 9;255(Pt 1):113216. Epub 2019 Sep 9.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.

The performance, microbial community and enzymatic activity of sequencing batch reactors (SBRs) were investigated under 75-day exposure of different Cu(II) concentrations. Cu(II) at 0-5 mg/L had no distinct impact on the chemical oxygen demand (COD) and nitrogen removal, oxygen-uptake rate (OUR), nitrification and denitrification rate, and microbial enzymatic activity. The inhibitory effects of Cu(II) at 10 and 30 mg/L on the nitrogen removal rate, OUR, and microbial enzymatic activity of SBR increased with an increment in operation time due to the Cu(II) biotoxicity and the Cu(II) accumulation in activated sludge. The changes of microbial reactive oxygen species production, lactate dehydrogenase release, catalase activity and superoxide dismutase activity demonstrated that Cu(II) at 10 and 30 mg/L broke the equilibrium between the oxidation and antioxidation processes in microbial cells and also damaged the cytomembrance integrity, which could affect the COD and nitrogen removal performance and change normal microbial cell morphology. The Cu(II) in the influent could be removed by the microbial absorption and accumulated in the activated sludge under long-term exposure. The microbial community displayed some distinct changes from 0 to 30 mg/L Cu(II). In contrast with 0 mg/L Cu(II), Nitrosomonas, Nitrospira and some denitrifying bacteria obviously decreased in relative abundance under long-term exposure of 10 and 30 mg/L Cu(II).
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http://dx.doi.org/10.1016/j.envpol.2019.113216DOI Listing
December 2019

Nitrogen removal pathway and dynamics of microbial community with the increase of salinity in simultaneous nitrification and denitrification process.

Sci Total Environ 2019 Dec 22;697:134047. Epub 2019 Aug 22.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, 266100 Qingdao, China; College of Environmental Science and Engineering, Ocean University of China, 266100 Qingdao, China.

In this study, simultaneous nitrification and denitrification (SND) process was successfully established in a hybrid sequencing batch biofilm reactor (HSBBR). High removal efficiency of NH-N (98.0±2.4% to 99.8±0.4%) and COD (86.6±4.0% to 91.6±1.8%) was observed in the salinity range of 0.0 to 2.4%. SND via nitrite, replacing SND via nitrate, became the main nitrogen removal pathway at 1.6% and 2.4% salinity. Suspended sludge and biofilm shared similar microbial composition. Dominant genera were substituted by salt-adaptable microbes as salinity increasing. Abundance of autotrophic ammonia-oxidizing bacteria (Nitrosomonas) increased with elevated salinity, while autotrophic nitrite-oxidizing bacteria (Nitrospira) exhibited extreme sensitivity to salinity. The presence of Gemmata demonstrated that heterotrophic nitrification co-existed with autotrophic nitrification in the SND process. Aerobic denitrifiers (Denitratisoma and Thauera) were also identified. Thiothrix, Sedimenticola, Sulfuritalea, Arcobacter (sulfide-based autotrophic denitrifier) and Hydrogenophaga (hydrogen-based autotrophic denitrifier) were detected in both S-sludge and biofilm. The occurrence of ANAMMOX bacteria Pirellula and Planctomyces indicated that ANAMMOX process was another pathway for nitrogen removal. Nitrogen removal in the HSBBR was accomplished via diverse pathways, including traditional autotrophic nitrification/heterotrophic denitrification, heterotrophic nitrification, aerobic and autotrophic denitrification, and ANAMMOX.
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http://dx.doi.org/10.1016/j.scitotenv.2019.134047DOI Listing
December 2019

Insights into long-term effects of amino-functionalized multi-walled carbon nanotubes (MWCNTs-NH) on the performance, enzymatic activity and microbial community of sequencing batch reactor.

Environ Pollut 2019 Nov 27;254(Pt B):113118. Epub 2019 Aug 27.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Qingdao 266100, China. Electronic address:

Carbon nanotubes (CNTs) inevitably enter domestic sewage and industrial wastewater with the continuous increase of their production and application field. The potential effect of CNTs on biological wastewater treatment processes has raised wide concerns due to their biotoxicity. In the present study, the performance, microbial community and enzymatic activity of sequencing batch reactors (SBRs) were evaluated under 148-day exposure of amino-functionalized multi-walled CNTs (MWCNTs-NH) at 10 and 30 mg/L. The COD removal efficiency at 10 and 30 mg/L MWCNTs-NH gradually reduced from 91.03% and 90.43% on day to 89.11% and 86.70% on day 148, respectively. The NH-N removal efficiency at 10 and 30 mg/L MWCNTs-NH gradually reduced from 98.98% and 98.46% on day 1 to 96.65% and 63.39% on day 148, respectively. Compared to 0 mg/L MWCNTs-NH, the oxygen-utilizing rate, ammonia-oxidizing rate, nitrite-oxidizing rate, nitrite-reducing rate and nitrate-reducing rate at 30 mg/L MWCNTs-NH were decreased by 52.35%, 60.58%, 55.12%, 56.56% and 57.42% on day 148, respectively. The microbial reactive oxygen species and lactate dehydrogenase release on day 148 was increased by 59.71% and 55.28% at 30 mg/L MWCNTs-NH, respectively. The key microbial enzymatic activity related to nitrogen removal decreased with the increase of operation time under MWCNTs-NH stress. The relative abundances of Nitrosomonas, Nitrosospira, Nitrospira and some denitrifying bacteria at 10 mg/L MWCNTs-NH gradually reduced with an increment in operation time. The changes of nitrogen removal rate, microbial community and enzymatic activity of SBR were related to the time-cumulative nonlinear inhibition effect under long-term exposure.
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http://dx.doi.org/10.1016/j.envpol.2019.113118DOI Listing
November 2019

Optimization of operating conditions for the acidification metabolites production with waste sludge using response surface methodology (RSM).

Environ Sci Pollut Res Int 2019 Oct 20;26(29):30303-30312. Epub 2019 Aug 20.

College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.

The acidification liquid of waste activated sludge (WAS) could be used as the additional carbon source of biological nutrient removal. Recently, the optimization of operating conditions for the acidification metabolites has attracted much attention. In this study, a three-factor Box-Behnken design (BBD) was applied to determine the relative importance of the various factors and the optimum operating during acidification using response surface method (RSM). The importance of the individual variables on the production of soluble chemical oxygen demand (SCOD) was suspended solids (SS) > shaking rate > initial oxidation-reduction potential (ORP). The increase on SS content led to a decrease on the acidification degree. Low SS could promote mass exchange and microbial activity. The maximum SCOD yield (9288.5 mg/L) was predicted under the optimum condition at 8.0 g/L SS, 144.0 mV initial ORP, and 60.0 r/min shaking rate. Also, the releasing of soluble protein and carbohydrate was calculated as responses. The individual effect of shaking rate and initial ORP had significant effect on soluble protein and carbohydrate releasing, respectively. This study would provide valuable information for increasing the efficiency of acidification.
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http://dx.doi.org/10.1007/s11356-019-06088-9DOI Listing
October 2019

Accelerating waste sludge hydrolysis with alkyl polyglucose pretreatment coupled with biological process of thermophilic bacteria: Hydrolytic enzyme activity and organic matters transformation.

J Environ Manage 2019 Oct 24;247:161-168. Epub 2019 Jun 24.

College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.

A novel pretreatment method combining thermophilic bacteria (TB) with alkyl polyglucose (APG) was employed to pretreat waste sludge for enhancing the sludge hydrolysis. TB combined with APG pretreatment was effective in the releasing of soluble chemical oxygen demand (SCOD), protein and carbohydrate in extracellular polymeric substances (EPS) when the dosage of APG was below 0.1 g/g TSS. The enhancement of SCOD, carbohydrates and protein in dissolved organic matter (DOM) was promoted by the synthetic effect of APG and TB, which provides more carbon and energy source to the subsequent biochemical processes in sludge digestion. Excitation-emission matrix (EEM) fluorescence spectroscopy revealed that the combined pretreatment was beneficial for the decrease of non-biodegradable materials and the increase of biodegradable materials in DOM, resulting in the enhancement of the biodegradation of waste sludge. The combined use of TB and 0.4 g/g TSS APG achieved the maximal activities of protease (1.8) and α-glucosidase (1.9), and the activities of protease and α-glucosidase were positively correlated to the dosage of APG. The combined pretreatment was advantageous for the sludge reduction and sludge stabilization.
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http://dx.doi.org/10.1016/j.jenvman.2019.06.071DOI Listing
October 2019

Effects of aluminum oxide nanoparticles on the performance, extracellular polymeric substances, microbial community and enzymatic activity of sequencing batch reactor.

Environ Technol 2021 Jan 14;42(3):366-376. Epub 2019 Jun 14.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, People's Republic of China.

The performance, pollutant removal rate, microbial community and enzymatic activity of a sequencing batch reactor (SBR) were investigated under oxide nanoparticles (AlO NPs) stress. AlO NPs at 0-50 mg/L showed no evident impact on the COD and NH removals of SBR. The oxygen-uptake rate, nitrifying rate and nitrite-reducing rate slightly diminished with the increase of AlO NPs concentration. Compared with 0 mg/L AlO NPs, the dehydrogenase activity declined by 23.52% at 50 mg/L AlO NPs. The activities of ammonia monooxygenase, nitrite oxidoreductase and nitrite reductase decreased with the increase of AlO NPs concentration from 0 to 50 mg/L AlO NPs. However, the nitrate reductase (NR) activity slightly increased at 5 and 15 mg/L AlO NPs and declined at 30 and 50 mg/L AlO NPs. The microbial reactive oxygen species (ROS) production and lactate dehydrogenase (LDH) release merely raised 14.80% and 20.72% at 50 mg/L AlO NPs by contrast with 0 mg/L AlO NPs, respectively. AlO NPs enhanced the production, protein content and polysaccharide content of extracellular polymeric substances owing to preventing the microbes from AlO NPs biotoxicity. The existence of AlO NPs led to the variations of microbial richness and diversity in the SBR due to their biotoxicity.
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http://dx.doi.org/10.1080/09593330.2019.1629182DOI Listing
January 2021

Insights into the effect of nickel (Ni(II)) on the performance, microbial enzymatic activity and extracellular polymeric substances of activated sludge.

Environ Pollut 2019 Aug 30;251:81-89. Epub 2019 Apr 30.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China. Electronic address:

The performance, nitrogen removal rate, microbial enzymatic activity and extracellular polymeric substances (EPS) of activated sludge were assessed under nickel (Ni(II)) stress. The organic matter and NH-N removal efficiencies were stable at less than 10 mg/L Ni(II) and subsequently decreased with the increment of Ni(II) concentration from 10 to 30 mg/L. The specific oxygen uptake rate and dehydrogenase activity kept stable at less than 5 mg/L Ni(II) and then declined at 5-30 mg/L Ni(II). Both specific ammonia-oxidizing rate (SAOR) and specific nitrite-oxidizing rate (SNOR) decreased with the increment of Ni(II) concentration. The changing trends of ammonia monooxygenase and nitrite oxidoreductase activities were matched those of SAOR and SNOR, respectively. The nitrite-reducing rate and nitrate-reducing rate illustrated a similar variation tendency to the nitrite reductase activity and nitrate reductase activity, respectively. Ni(II) impacted on the production, chemical composition and functional group of EPS. The relation between the sludge volume index and the EPS production exhibited a better linear function with a negative slope, demonstrating that Ni(II) improved the sludge settleability despite of the increase of EPS production.
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http://dx.doi.org/10.1016/j.envpol.2019.04.094DOI Listing
August 2019

Long-term impacts of carboxyl functionalized multi-walled carbon nanotubes on the performance, microbial enzymatic activity and microbial community of sequencing batch reactor.

Bioresour Technol 2019 Aug 25;286:121382. Epub 2019 Apr 25.

Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China. Electronic address:

The performance, microbial community and enzymatic activity of sequencing batch reactors (SBRs) were evaluated under long-term exposure of 0, 10 and 30 mg/L carboxyl functionalized multi-walled carbon nanotubes (MWCNTs-COOH). The presence of 10 mg/L MWCNTs-COOH displayed no adverse impacts on the COD and NH-N removal of SBR, whereas 30 mg/L MWCNTs-COOH declined the COD and NH-N removal. MWCNTs-COOH inhibited the denitrifying process and led to the accumulation of effluent NO-N concentration. The inhibition of MWCNTs-COOH on the oxygen utilization rate, nitrogen removal rate and enzymatic activity of activated sludge gradually enhanced with the increase of operating time and influent MWCNTs-COOH concentration. MWCNTs-COOH stimulated more reactive oxygen species production and lactate dehydrogenase release, which might affect the microbial physiological functions and morphology. The microbial diversity and richness was declined evidently after long-term exposure of MWCNTs-COOH. The relative abundance of nitrifying and denitrifying bacteria showed some changes under MWCNTs-COOH stress.
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http://dx.doi.org/10.1016/j.biortech.2019.121382DOI Listing
August 2019

Enhancing the hydrolysis of saline waste sludge with thermophilic bacteria pretreatment: New insights through the evolution of extracellular polymeric substances and dissolved organic matters transformation.

Sci Total Environ 2019 Jun 12;670:31-40. Epub 2019 Mar 12.

College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.

Recently, the treatment and utilization of saline waste sludge has drawn growing attention because large amounts of saline waste sludge were generated with the increase of saline wastewater discharge. In this study, thermophilic bacteria (TB) pretreatment was applied to accelerate the hydrolysis of saline waste sludge and the efficiency of hydrolysis at different salinities was evaluated. Compared with the group without salinity, the releasing of carbohydrate (up to a 67.0% decrease) in extracellular polymeric substances (EPS) was inhibited at the salinity ranging from 1.0% to 2.5%, and the releasing of protein (up to a 17.6% decrease) was inhibited under salinity conditions. Excess salinity (4.0%) caused the cell lysis, and the content of soluble chemical oxygen demand (SCOD), soluble carbohydrate and protein in dissolved organic matter (DOM) increased by 44.9%, 38.8% and 20.8% than that obtained without salinity, respectively. According to the excitation-emission matrix (EEM) fluorescence spectroscopy, the biodegradability of sludge was improved at 2.0% salinity. At 2.0% salinity, the maximum fluorescence intensity of soluble microbial byproduct substances (76,358.9 (au)) and the minimum fluorescence intensity of humic acid-like substances (173,424 (au)) were obtained. The increased salinity was beneficial for the sludge stabilization and was disadvantageous for the sludge reduction.
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http://dx.doi.org/10.1016/j.scitotenv.2019.03.158DOI Listing
June 2019

Enhancing denitrification efficiency for nitrogen removal using waste sludge alkaline fermentation liquid as external carbon source.

Environ Sci Pollut Res Int 2019 Feb 18;26(5):4633-4644. Epub 2018 Dec 18.

College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.

External carbon source was usually added to enhance denitrification efficiency for nitrogen removal in wastewater treatment. In this study, waster sludge alkaline fermentation liquid was successfully employed as an alternative carbon source for biological denitrification. The denitrification performance was studied at different C/Ns (carbon-to-nitrogen ratios) and HRTs (hydraulic retention times). A C/N of 7 and an HRT of 8 h were the optimal conditions for denitrification. The nitrate removal efficiency of 96.4% and no obvious nitrite accumulation in the effluent were achieved under the optimal conditions with a low soluble chemical oxygen demand (SCOD) level. The sludge carbon source utilization was analyzed and showed that the volatile fatty acids (VFAs) were prior utilized than proteins and carbohydrates. The excitation-emission matrix (EEM) spectroscopy with fluorescence regional integration (FRI) was adopted to analyze the compositional and variations of dissolved organic matters (DOM). Moreover, a high denitrification rate (V) and potential (P) with low heterotroph anoxic yield (Y) was exhibited at the optimal C/N and HRT condition, indicating the better denitrification ability and organic matter utilization efficiencies.
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http://dx.doi.org/10.1007/s11356-018-3944-4DOI Listing
February 2019