[Rapid Start-up of Continuous Autotrophic Nitrogen Removal Reactor by Hybrid-inoculating PN and PN/A Granular Sludges].

The rapid cultivation of partial nitritation/ANAMMOX （PN/A） granular sludge in a continuous-flow mode is one of the key technologies for efficient biological nitrogen removal in domestic wastewater treatment. Compared with that in PN/A granular sludge, PN granular sludge demonstrates a shorter incubation period and suitability for batch culture. It is also a good carrier for enriching ANAMMOX （AMX） bacteria.

[Characterization of Sludge Morphology and Bacterial Community Evolution in the Rapid Activation of Freeze-stored PN/A Granular Sludge].

Inoculating granular sludge is an alternative method for the quick start-up of a high-performance autotrophic nitrogen removal reactor. In order to establish the response relationship between sludge activation and reactor performance, the freeze-stored granular sludge was inoculated into a continuous-flow reactor, and a control strategy of the high loading rate and high hydraulic selective pressure was carried out in this study. As a result, a one-stage partial nitritation/ANAMMOX process was started up in 34 days, and the removal efficiency of total nitrogen was over 83%, with a removal loading rate of total nitrogen of 1.

[Effects of Cold Acclimation on the Activity of Autotrophic Nitrogen Removal in Granular Sludge and Its Bacterial Population Structure].

Cold acclimation is an effective approach for improving the nitrogen removal performance and operational stability of partial nitritation/ANAMMOX (PN/A) combined processes at low temperatures. To explore the specific effects of cold acclimation on the characteristics of sludge, differentiations in temperature sensitivity, granular morphology, composition of extracellular polymer substance (EPS), and bacterial community structure between PN/A granular sludges cultivated at medium-high temperature (30℃) and acclimated to low temperature (15℃) were investigated in this study. The results of reaction thermodynamics showed that the nitrogen removal performance of the granules acclimated to low temperature (G) was significantly higher than that of those cultivated at medium-high temperature (G) under the low temperature (10-20℃), and the apparent activation energy () of total inorganic nitrogen removal for the former was decreased by 28.

[Adaptability of Completely Autotrophic Nitrogen Removal over Granular Sludge to Low-Strength at Low Temperature].

A single-stage PN-ANAMMOX (PN/A) granular sludge cultured at room temperature was used to investigate the completely autotrophic nitrogen removal efficiency and microbial community structure of low-strength wastewater based on the completely autotrophic nitrogen removal over nitrite in granular sludge at a low temperature. The results showed that at the low temperature (15±1)℃, the ammonia nitrogen load was maintained at 1.29 kg ·(m ·d), and the ammonia nitrogen concentration in the injection was gradually reduced from 70 mg ·L to 40 mg ·L.

[Impact of Hydraulic Retention Time on Performance of Partial Nitrification Granular Sludge in Continuous Stirred-Tank Reactor].

The effects of different hydraulic retention time (HRT) on short-cut nitrification granular sludge were studied in a continuous stirred-tank reactor (CSTR) by maintaining stable influent ammonia nitrogen load. Particle size distribution, extracellular polymeric substances (EPS), and functional bacterial kinetics were analyzed. The morphology of granular sludge, the performance of the CSTR, and the activity of functional microorganisms were investigated.

[Start-up of a Three-stage PN/A Granular Sludge Reactor for Treating Wastewater with High Concentrations of Ammonia].

In order to apply partial nitritation-ANAMMOX (PN/A) technology to treat wastewater with high concentrations of ammonia, autotrophic nitrogen-removing granular sludge was crushed and inoculated into a three-stage continuous flow reactor. The nitrogen loading rate (NLR), dissolved oxygen (DO) concentration, and free ammonia (FA) levels in each compartment of the reactor were controlled over a 106-day period. Results showed that the nitritation process occurred with the inoculated granules during the initial phase.

[Start-up Performance and Sludge Characteristics of Single-stage Autotrophic Nitrogen Removal System with Granular Sludge at Low Ammonia Nitrogen Concentration at Room Temperature].

The start-up and stable operation of single-stage autotrophic nitrogen removal process under low ammonia nitrogen substrate at room temperature appears as the premise and basis for the application in municipal wastewater treatment. In this study, the PN/A (partial nitritation and ANAMMOX) granular sludge for long-term storage was inoculated into an air-lift bioreactor to investigate the nitrogen removal performance during the start-up of single-stage partial nitritation and ANAMMOX process under the following conditions:temperature at (23±2)℃, pH at 7.7-8.

[High-rate Nitrogen Removal in a Two-stage Partial Nitritation-ANAMMOX Process Under Mainstream Conditions].

A two-stage partial nitritation (PN)-ANAMMOX process was successfully carried out for low-strength NH-N (50 mg·L) wastewater treatment at ambient/low temperatures. The results show that an average total nitrogen removal rate and removal efficiency above 0.6 kg·(m·d)and 80% could be maintained, respectively, at temperatures between 20℃ and 14℃.

[Effects of Nanoscale Zero-valent Iron (nZVI) on Denitrifying Performance of an Upflow Granular Sludge Bed Reactor].

In order to examine the effects of nanoscale zero-valent iron (nZVI) on the performance of denitrifying granular sludge (DGS) in a continuous flow model, the variations of nitrogen removal efficiency in the reactor, sludge morphology, and denitrifying characteristics at different influent nZVI concentrations were investigated in an upflow sludge bed (USB). The results showed that nZVI concentrations lower than 5 mg·L did not influence the nitrogen removal performance of the reactor significantly, and the activity of DGS was improved slightly. When the influent nZVI concentration was in the range of 5 to 10 mg·L, the DGS could adapt to the biological inhibition of nZVI partially, with the increase of sludge concentration and grain size.

[Start-up of a High Performance Nitrosation Reactor Through Continuous Growth of Aerobic Granular Sludge].

In order to examine the continuous growth capacity of the nitrosation granular sludge (NGS), the sludge was inoculated to start up the columnar sequencing batch reactor (SBR). During 130 d, the concentration of mixed liquor suspended solids (MLSS) in SBR increased from 0.1 g·L to 11.

[Contamination Characterization and Human Exposure Levels to Polybrominated Diphenyl Ethers in Indoor and Outdoor Air in Industrial Park of Suzhou City].

Eight polybrominated diphenyl ether (PBDE) congeners in indoor and outdoor air particles were collected using higher-volume active sampling techniques from different functional areas, including an industrial workplace, office, domestic area, and scenic area in an industrial zone, in Suzhou city, and the samples were analyzed by GC-MS. The total concentration of PBDEs ranged from 9.22-64.

[Impact of Biodegradable Organic Matter on the Functional Microbe Activities in Partial Nitrification Granules].

To explore the short-term impact of biodegradable organic matter on the activities of different functional microbes in autotrophic partial nitrification granular sludge (PNG),the variations of both nitrogen transformation performance and dissolved oxygen (DO) uptake of PNG were investigated in this study,by carrying out successive batch tests with and without the organics stressing.The results showed that the higher the C/N ratio,the lower the specific nitrite accumulation rate of (NO-N).Meanwhile,the increase of heterotrophic bacteria (HeB) activities caused the fast DO uptake by PNG,which could effectively suppress nitrite oxidizing bacteria (NOB) with the low oxygen affinity.

[Effect of Increasing Organic Loading Rate on the Formation and Stabilization Process of Aerobic Granular Sludge].

In order to evaluate the effect of organic loading rate ( OLR) on the formation of aerobic granular sludge (AGS), a lab-scale cylindrical SBR reactor (sodium acetate as carbon source) was constructed and inoculated with collected sewage sludge. The evolution of morphology, microbial activity and extracellular polymeric substances (EPS) characteristics of sludge samples in the reactor were recorded and analyzed. The results showed that AGS has the highest growth rate under the condition of 3.

[Study on removal effect of different organic fractions from bio-treated effluent of dye wastewater by UV/H2O2 process].

The pretreatment of bio-treated effluent of dye wastewater by UV/H2O2 process was studied. The influencing factors, such as H2O2 dosage, reaction time and pH values were evaluated for the removal efficiency of UV254, ADMI7.6, DOC and DOC of dye wastewater by UV/H2O2 process.