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In the present study, a total of 1130 soil samples were collected in 2003 and 2013 in the Ningbo city district, and the content of eight typical heavy metals were measured. The degree of heavy metal pollution in the soil in the study area was evaluated using the pollution index evaluation method. The temporal and spatial variation in the pollution were analyzed by the geostatistics method, and principal component analysis (PCA) and the UNMIX model were used to analyze the heavy metal pollution sources. The results showed that:① excluding As, the mean values of the other seven heavy metals in both periods exceeded the soil background values in Zhejiang province and national background values, which indicated that heavy metal pollution is common in the soil from the study area. From 2003 to 2013, the mean content of all elements increased to some degree, indicating that the heavy metals pollution was generally aggravated in 10 a; the increase in the mean Hg content was the greatest. ② The evaluation results based on the single-factor pollution index showed that the pollution degree was high for Hg; moderate for Cd, Cu, and Pb; slight for Zn, Cr, and Ni; and unpolluted for As. The evaluation results based on Nemero's comprehensive pollution index showed that the pollution index for all samples exceeded the precaution value, and the number of soil samples that were characterized as heavily polluted with a comprehensive pollution index over 3 had increased significantly. ③ The spatial distribution of the same heavy metal in different periods presented similar characteristics. Generally speaking, the spatial distribution of Pb was similar to that of Hg, and the spatial distributions of Cr, As, Cu, Zn, and Ni were similar to each other; high value areas were mainly concentrated in the four areas of Haishu, Jiangbei, Jiangdong, and Zhenhai districts, where the polluted enterprises were densely distributed and human activities were frequent. ④ Based on PCA and the UNMIX receptor model, the source analysis results of soil heavy metals in 2013 were essentially the same, i.e., the source of heavy metal pollution in the study area included industrial sources and living sources. Industrial sources of heavy metal pollution had the highest contribution rate and derived from industrial wastewater, waste gas, and waste residue discharged by plasticizing, mining, and metallurgical enterprises; chemical and mechanical manufacturing enterprises; etc., causing the accumulation of Cr, As, Cu, Zn, and Ni in the soil. The living sources had the second highest contribution rate and originated from the pollution of particulates and dust caused by domestic waste, automobile exhaust, and road wear. Additionally, natural factors had small contribution rates, mainly due to the spread of pollutants by prevailing winds and atmospheric settlement.

In order to investigate the effect of temperature on the cellulose-degrading bacteria and denitrifying bacteria, the denitrification and phosphorus removal of solid carbon source of cellulose corncob+sulfur/sponge iron nitrogen and phosphorus removal composite system, abbreviated as SCSC-S/Fe, was analyzed under different temperature conditions, and the surface structure and microbial properties of corncob before and after reaction were analyzed by scanning electron microscope (SEM) and MiSeq high-throughput sequencing technologies. The results indicated that when temperature increased from 15, 20, 25 to 30℃, the average TN removal rate of the system increased from 78.88% to 92.70%, the average removal rate of TP increased from 82.58% to 89.15%;microbial properties showed that the surface reaction after corncob was dominated by spherical and rod-shaped microorganisms; the proportion of cellulose-degrading bacteria was 11.01% higher at 30℃ than 20℃, and the proportion of denitrifying bacteria decreased by 21.26%. It can be seen that the cellulose -degrading bacteria were more sensitive to the temperature than the denitrification bacteria, and more obviously affected by the temperature.

In order to improve the ability of denitrification and phosphorus removal from reclaimed water, a novel composite filler was prepared using sulfur powder and sponge iron powder, and a comparative experiment was constructed at different HRT(hydraulic retention time) and C/N(carbon-nitrogen ratio) conditions between the novel filler and the composite filler. The results showed that the efficiency of nitrogen and phosphorus removal on the novel filler was higher than that on the grain filler (more than 30% higher at HRT=4 h and C/N=1). Moreover, based on the 16S rRNA gene clone library, the denitrification system in the two reactors included sulfur autotrophic denitrification bacteria and heterotrophic denitrification bacteria, while the proportion of sulfur autotrophic denitrification bacteria in the novel filler system was higher. The dominant bacteria in the novel filler and composite filler were

The strain Ochrobactrum sp. CH10 was a highly efficient phenol degrading bacterial strain isolated from soil in a constructed wetland in Yuan Dynasty Capital City Wall Relics in Beijing. Growth and biodegradation were investigated in details with phenol as the sole carbon and energy source. The best growth and most efficient phenol biodegradation occurred when the strain was cultured in medium containing 400 mg x L(-1) phenol at initial pH of 7.0 and 30 degrees C, with 5% inoculation volume. The phenol degradation rate was around 100% , 92.3 and 82.2% with an initial concentration of 400, 900 and 1 000 mg x L(-1) phenol in 24, 44 and 48 h, respectively. Phenol degradation kinetic studies indicated that the strain followed Haldane's model, and the parameters were: upsilon(max) (maximum specific rate) = 0.126 h(-1), K(s) (half-saturation constant) = 23.53 mg x L(-1) and K(I) (inhibition constant) = 806.1 mg x L(-1). The phenol-limited growth kinetics of CH10 by Andrews's model also followed a similar trend to that of phenol degradation. Among all the strains belonging to Ochrobactrum genus, this strain is the most efficient at present. The strain has a good application potential for the phenolic wastewater treatment.