Applying sheet iron to enhance the treatment efficiency of digested effluent with continuous flow and the corresponding mechanism.

Because of the unstable wastewater quantity and quality, the biological treatment efficiency of digested effluent was not as expected. A convenient and effective way was eagerly required to improve the efficiency of biological treatment. By sheet iron addition (R), the COD and TN removal efficiencies under continuous flow condition increased by 59% and 37% respectively.

The long-term effect of glutaraldehyde on the bacterial community in anaerobic ammonium oxidation reactor.

A 160-day incubation was performed with two anammox reactors (GA and CK) to investigate the effect of glutaraldehyde. The results indicated that anammox bacteria were very sensitive when glutaraldehyde in GA reactor increased to 40 mg/L, the nitrogen removal efficiency sharply decreased to 11%, only one-quarter of CK. Glutaraldehyde changed spatial distribution of exopolysaccharides, caused anammox bacteria (Brocadia CK_gra75) to disassociate from granules (24.

Aggregation enhances the activity and growth rate of anammox bacteria and its mechanisms.

The aggregation of anaerobic ammonium oxidation (anammox) bacteria is important for the start-up and biomass retention of anammox processes. However, it is unclear whether it is beneficial to the activity, growth and reproduction of anammox bacteria. In this study, four reactor systems were developed to explore the effects of aggregation on anammox activity, growth and reproduction, after excluding the contribution of aggregation to sludge settling and retention.

[Effect of Different Temperatures on the Performance of Autotrophic Nitrogen Removal and Microbial Community from Swine Wastewater].

Four laboratory-scale autotrophic nitrogen removal bioreactors were implemented to investigate performance differences and microbial mechanisms under different temperatures (30, 25, 20, and 15℃). The results showed that the reactor performance under 30℃ was higher than others. When the temperature decreased from 30℃ to 25℃, total nitrogen removal efficiency reduced from 73% to 66%, and total nitrogen removal rate from 2.

A Phosphate-Starvation Induced RING-Type E3 Ligase Maintains Phosphate Homeostasis Partially Through OsSPX2 in Rice.

Phosphate (Pi), as the main form of phosphorus that can be absorbed by plants, is one of the most limiting macro-nutrients for plants. However, the mechanism for maintaining Pi homeostasis in rice (Oryza sativa) is still not well understood. We identified a Pi-starvation-induced E3 ligase (OsPIE1) in rice.

Continuous dry fermentation of swine manure for biogas production.

A down plug-flow anaerobic reactor (DPAR) was designed for the feasibility study on continuous dry fermentation of swine manure without any additional stirring. Using fresh swine manure as the feedstock with TS concentration (w/w) of 20%, 25%, 30%, and 35%, stable volumetric biogas production rates of 2.40, 1.

The effects of temperature, organic matter and time-dependency on rheological properties of dry anaerobic digested swine manure.

An efficient way to avoid the pollution of swine wastewater is the application of dry anaerobic digestion, which needs rheological parameter for stirring and pipe designing. The rheological properties of this kind of sludge have been studied for many decades, yet their effects only solid concentration has been investigated widely. In this paper, the influences of temperature, organic and time-dependency on the efficiency of anaerobic digested swine manure were studied.

Comparison of constructed wetland and stabilization pond for the treatment of digested effluent of swine wastewater.

A laboratory-scale horizontal subsurface flow constructed wetland (HSFCW) and a stabilization pond (SP) were constructed to compare their performances on the treatment of digested effluent of swine wastewater. After 457 days of operation, the removal efficiencies of the HSFCW were as follows: chemical oxygen demand (COD), 17-54%; total phosphorus (TP), 32-45% and ammonia nitrogen [Formula: see text], 27-88%, while they were 25-55%, 31-56% and 56-98%, respectively, for the SP, with a hydraulic retention time of 54 days and hydraulic loading of 0.01 m³ m⁻² d⁻¹.

[Effects of the ratio of NO3(-) -N to NO2(-) -N on the removal of sulfide and nitrogen by mixed culture and pure culture].

Effects of the ratio of NO3(-) -N to NO2(-) -N on removal of sulfide and nitrogen by Pseudomonas fluorescens, Pseudomonas aeruginosa and mixed culture were investigated at the pH value of 7.0, temperature of 30 degrees C, ratio of sulfide to nitrate of 5/3 and anaerobic condition. Along with the decrease of ratio of NO3(-) -N to NO2(-) -N, NO(x)(-) -N, the removal rate by Pseudomonas fluorescens and Pseudomonas aeruginosa increased gradually, while S(2-) removal rate reduced.

[Continuous dry fermentation of pig manure using up plug-flow type anaerobic reactor].

To solve the problems of ammonia inhibition and discharging difficulty in continuous dry fermentation of pig manure, under the experimental conditions of temperature of (25 +/- 2) degrees C and organic loading rate (TS) of 4.44 g x (L x d) (-1), a lab-scale up plug-flow type anaerobic reactor (UPAR) was setup to investigate biogas production, ammonia inhibition, effluent liquidity, and the feasibility of continuous dry fermentation of pig manure using up plug-flow type anaerobic reactor. The experiment was operated for 160 days using the pig manure with four different TS mass fractions (20%, 25%, 30%, 35%) as feeding.

Influence of sand layer depth on partial nitritation as pretreatment of anaerobically digested swine wastewater prior to anammox.

This work aimed to investigate the influence of sand layer depth on partial nitritation performance as a preparative step for anaerobic ammonium oxidation (anammox) process in treating anaerobically digested effluent of swine wastewater. A lab-scale biological sand filter system was constructed and partial nitritation was successfully maintained with nitrogen loading rate (NLR) of approximately 50 g NH(4)(+)-N m(-3) d(-1). An average NH(4)(+)-N removal efficiency of 61.

[Effect of sulfide to nitrate ratios on the strains coupling nitrogen removal from wastewater and hydrogen sulfide removal from biogas].

Two strains Pseudomonas fluorescens and Pseudomonas aeruginosa were isolated from the reactors coupling nitrogen removal from wastewater and hydrogen sulfide removal from biogas. It was investigated that sulfide to nitrate ratios had effects on the simultaneous removal of sulfide and nitrate of the two strains under the conditions of pH 7.0, temperature 30 degrees C, anaerobic, cultured for 2 days.

[Effect of the ratio of height to diameter on the performance of the simultaneous reactor for nitrogen removal from swine wastewater and sulfide removal from biogas].

The effect of the ratio of height to diameter (H/D) on the process of simultaneous nitrogen removal from swine wastewater and hydrogen sulfide removal from biogas was investigated, using the bubble column reactors with packing material. The performance of the reactor with H/D of 8 : 1, 3 :1 and 2 : 1 was compared. Under temperature of 30-32 degrees C, gas retention time of 6.

[Cultivation and isolation of bacteria coupling nitrogen removal from wastewater and hydrogen sulfide removal from biogas].

It was studied that during the startup of reactors the crucial bacteria coupling nitrogen removal from swine wastewater and hydrogen sulfide removal from biogas using bubbling absorption reactors without seeding sludge, with seeding anaerobic sludge and aerobic sludge, respectively. During the prophase of the experiment (before the 26th d), the removal rate of nitrogen and hydrogen sulfide were from 50% to 64% in reactors with seeding sludge, that in the reactor without seeding sludge was only 11%-14%. At the end of experiment (the 56th d after startup), the removal rates of nitrogen for three reactors were about 90%.

[Impact of proportion of adding raw wastewater on post-treatment of digested piggery wastewater].

Sequencing batch reactor (SBR) was used to treat digested piggery wastewater, in order to investigate the impact of proportion of adding raw wastewater. In consecutive experiments, the reactor with adding 30% raw wastewater could get low ammonia nitrogen (NH3-N), usually less than 10 mg/L in the effluent, while the reactors with adding 10% or 20% raw wastewater, concentration of NH3-N increased by degrees until reached 300 mg/L or 80 mg/L respectively at end of experiment. These can be explained by the facts that the reactor with adding 30% raw wastewater could maintain stable pH (about 7.

[Performance improvement of sequencing batch reactor (SBR) treating digested piggery wastewater by addition of raw wastewater].

When digested piggery wastewater was directly treated with a sequencing batch reactor (SBR) process, the efficiency was low with COD removal about 10% and NH4+ -N removal about 70%. The effluent COD concentration was higher than 1000 mg/L and effluent NH4+ -N concentration was 200 mg/L or so. The working state of the reactor was unstable and its performance deteriorated gradually during operation.