[Denitrification and Anaerobic Ammonium Oxidation in Soil Nitrogen Migration Process in a Farmland of Wanshandang Lake].

To explore the rate variation and contribution to N loss of denitrification and anaerobic ammonia oxidation (ANAMMOX) in the nitrogen migration process of farmland soils in southern China, we assess the physicochemical characteristics soil samples of different soil layers from farmland and different land use types (farmland, river channel, riparian zone, and lake sediment) in a wheat-rice rotation area of Wanshandang Lake. Illumina MiSeq sequencing and quantitative real-time polymerase chain reaction (qPCR) are used to investigate the microbial community composition and functional gene abundances of the samples. The potential denitrification and ANAMMOX rate (calculated by N) of each sample was determined by an isotope culture experiment.

[Insight into the Process of Mn-ANAMMOX in Soils of Agricultural Drainage Ditches].

Anaerobic ammonium oxidation mediated by MnO (termed Mn-ANAMMOX) is a newly discovered microbial nitrogen removal pathway. However, few studies have reported on the Mn-ANAMMOX process and related microbial communities in agricultural drainage ditches. In this study, Mn(Ⅳ)-reducing bacteria (MnBR) enrichment cultivation was carried out for 340 days and an isotope tracing technique and high-throughput sequencing technology were used to provide convincing evidence of the occurrence of Mn-ANAMMOX.

[Insight into the Mechanism of Feammox in the Surface Soils of a Riparian Zone].

Anaerobic ammonium oxidation coupled to iron (Ⅲ) reduction (termed Feammox) is a recently discovered pathway of nitrogen cycling. However, little is known about the pathways of N transformation via the Feammox process in riparian zones. In this study, evidence of Feammox in the riparian zone soil layers (0-20 cm) was demonstrated using the isotope tracing technique and a high-throughput sequencing technology.

[New Bromated Phenolic Disinfection Byproducts: Mechanism of Their Decomposition During Chlorination].

Recently, 13 new phenolic halogenated disinfection by-products (DBPs) have been reported in chlorinated drinking water and have been classified into four groups: dihalo-4-hydroxybenzaldehydes, dihalo-4-hydroxybenzoic acid, dihalo-salicylic acids, and trihalo-phenols. In this work, the four fully brominated species (3,5-dibromo-4-hydroxybenzoic acid, 3,5-dibromosalicylic acid, 2,4,6-tribromophenol, and 3,5-dibromo-4-hydroxybenzaldehyde) were selected as representatives, and the decomposition mechanism of these new DBPs during chlorination was studied with the aid of ultra performance liquid chromatography/electrospray ionization triple-quadrupole mass spectrometry (precursor ion scan, multiple reaction monitoring, and product ion scan). Except for 3,5-dibromosalicylic acid, the new DBPs were not stable and could be finally decomposed to haloacetic acids through multistep substitution, hydrolysis, and oxidation.

[Effect of Elodea nuttallii-immobilized Nitrogen Cycling Bacteria on Nitrogen Removal Mechanism in an Inflow River, Gonghu Bay].

Undisturbed sediment cores and surface water from Qinshui River in Gonghu Bay were collected to carry out a simulation experiment in our laboratory. The remediation effect of Elodea nuttallii-Immobilized Nitrogen Cycling Bacteria (INCB) was applied in the polluted inflow river. The denitrification rate, ANAMMOX rate and nitrogen microorganism diversity were measured by ¹⁵N isotope pairing technology and high-throughput sequencing technology based on 16S rRNA.

[Preparation of Nanocomposite Hydrogel and Its Adsorption of Heavy Metal Ions].

An acylamino and hydroxyl functionalized hydrogel [p(HMAm/HEA)] was newly prepared by the Co-γ-induced polymerization of -hydroxymethyl acrylamide (HMAm) and 2-hydroxyethyl acrylate (HEA). Then the copolymer p(HMAm/HEA) hydrogel was utilized for nanosized hydrous manganese dioxide (HMO) loading to prepare nanocomposite hydrogel HMO-p(HMAm/HEA) for Pb and Cu removal. The nanocomposite hydrogel was characterized by SEM, TEM and FTIR, showing that p(HMAm/HEA) hydrogel was indeed a copolymer of HMAm and HEA monomers, and the loading of HMO nanoparticles onto p(HMAm/HEA) was successful.

[Nitrogen uptake and denitrification study on the joint treatment of aquatic vegetation and immobilized nitrogen cycling bacteria in Taihu Lake].

Undisturbed sediment cores were collected from Meiliang Bay, Taihu Lake. Immobilized nitrogen cycling bacteria (INCB), Elodea nuttallii were added to four groups of restoration incubation chambers respectively to explore the nitrogen removal mechanism in different restoration treatments. uN tracer and isotope pairing technique were used to determine the rates of plant uptake and denitrification in different treatments.

[Denitrification study of Elodea nuttallii-nitrogen cycling bacteria restoration in Meiliang Bay, Taihu Lake].

Undisturbed sediment cores were collected from Meiliang Bay, Taihu Lake, and the integrated Elodea nuttallii-nitrogen cycling bacteria technology was applied as a restoration method. The effects of the Elodea nuttallii-nitrogen cycling bacteria technology on sediment denitrification was observed by isotope pairing technique. The highest denitrification rate of 104.

[Preparation of a novel modified hydrogel and study of its adsorption performance].

A novel copolymer hydrogel poly(Hydroxyethyl methacrylate/N-Vinylformamide) [p (HEA/NVF)] was prepared by 60Co-gamma induced copolymerization, using low-temperature radiation technique. Triethylenetetramine(TETA) was applied to modify the prepared hydrogel into an ammoniated hydrogel poly (Hydroxyethyl methacrylate/N-Vinylformamide) -TETA [p (H/V) -T]. The two hydrogels prepared were characterized by using FTIR spectrometry and the p (HEA/NVF) was scanned by SEM.

[Applied study of the submerged macrophytes bed-immobilized bacteria in drinking water restoration].

The effect of submerged macrophytes bed-immobilized bacteria technology which applied in drinking water restoration was studied. Ammonifying bacteria, nitrobacteria, nitrosobacteria and denitrifying bacteria which isolated from Taihu Labe was immobilized to the porous carries, combined with the submerged macrophytes bed technology, we applied the new equipment in water restoration of gonghu bay, this equipment has good ability to resist storm, the denitrifying bacteria number increased from 5.4 x 10(2)-2.

[Immobilized ammonia-oxidizing bacteria Comamonas aquatic LNL3 and its partial nitrification characterization].

A new kind of ammonia-oxidizing bacteria (AOB)-Comamonas aquatic LNL3 was screened out and immobilized by Poly (HEA)-Poly (HEMA) copolymer carrier using irradiation techniques. Four kinds of impact factors on short-cut nitrification, including temperature, pH, DO and free ammonia (FA) concentration had been investigated. The result showed that AOB-Comamonas aquatic LNL3 had short-cut nitrification capability and the optimal temperature, pH, DO and FA concentration were 30 degrees C, 8.

[Ecological engineering experiment for Jinshan Lake in Zhenjiang base on techniques of immobilized nitrogen cycling bacteria].

Nitrogen cycling bacteria, including ammonifying, nitrobacteria, nitrosobacteria and denitrifying bacteria were screened, carrier was made and immobilized nitrogen cycling bacteria (INCB) was prepared. The results demonstrated that ammonifying, nitrobacteria, nitrosobacteria and denitrifying bacteria were increased markedly in the experimental areas and root zone of aquatic plants by releasing of INCB. The results also showed that the average removal efficiencies for total N (TN), NH4(+) -N, NO3(-) -N and NO2(-) -N were 44.

[Stability of short-cut nitrification using immobilized ammonia-oxidizing bacteria].

The ammonia-oxidizing bacteria were immobilized by copolymer with cell proliferation technology. The effects of NH(4+) -N load, HRT, free ammonia (FA) and organic matter on short-cut nitrification process were studied. The results showed that when influent NH(4+) -N load were 100 mg/L, 150 mg/L and 200 mg/L respectively, effluent NH(4+) -N concentration was less than 10 mg/L.