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139 results on '"Ai, Hainan"'

29. Effects of green waste addition on waste activated sludge and fat, oil and grease co-digestion in mesophilic batch digester.

Author

Chen, Yongdong, Jiang, Qin, Zhu, Ruilin, Shi, Jinghua, Chai, Hongxiang, Li, Li, Ai, Hainan, Shi, Dezhi, He, Qiang, and Gu, Li

Subjects
FAT, FATS & oils, PETROLEUM, ELECTRIC conductivity, MICROBIAL diversity, ANAEROBIC digestion, DIGESTION
Abstract

Anaerobic digestion (AD) is regarded as an effective method to treat waste activated sludge (WAS) and fat, oil and grease (FOG). Co-digestion of WAS/FOG could promote the methane yield but it will cause acid and salinity inhibition. Green waste (GW) was added into the digesters, and its effects on co-digestion of WAS and FOG in the mesophilic batch digester were investigated. Digestive performances (such as hydrolysis, acidogenesis and methanogenesis) were studied emphatically. The results showed that digester L6 (WAS:FOG:GW = 1:2:1, VS basis) presented the highest specific methane yield (SMY, 341.5 mL/g VS). The results of kinetics study verified that there was a slower hydrolysis rate when GW was applied as a co-substrate, which could reduce the potential of acid inhibition. Volatile fatty acid (VFA) and electrical conductivity analysis showed that GW addition could keep moderate VFA concentrations and alleviate the negative effects of high-salinity substrates on the digestive systems. The microbial community and diversity analysis proved that GW addition was beneficial to keep the balance of hydrolytic bacteria, acidogens and acetogens. The results of this study indicated that GW addition could enhance the energy recovery and system stability in the WAS/FOG co-digestive system. [ABSTRACT FROM AUTHOR]

Published
2021
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34. Enhanced nitrate adsorption by using cetyltrimethylammonium chloride pre-loaded activated carbon.

Author

Xia, Fan, Yang, Haifeng, Li, Li, Ren, Yang, Shi, Dezhi, Chai, Hongxiang, Ai, Hainan, He, Qiang, and Gu, Li

Subjects
ACTIVATED carbon, ADSORPTION (Chemistry), NITRATES, NITRATE reductase, ADSORPTION capacity, CHLORIDES, ADSORBATES
Abstract

This paper used cetyltrimethylammonium chloride (CTAC) pre-loaded activated carbon (AC) to research nitrate adsorption. Effects of various parameters such as AC types, AC dosage as well as initial pH were studied. The results indicated that the ACs modified by CTAC can get higher nitrate removal. Even pH is neutral and basic, an accepted removal about 2.5 mg/g can be observed. The more CTAC pre-loaded on the AC surface, the higher nitrate adsorption capacity can be obtained. pH is regarded as a key factor affecting interactions between adsorbent and adsorbate, and the results confirmed that the nitrate adsorption on modified AC decreases gradually with the growth of initial pH. Besides, the acidic pH condition is much favoured for adsorption while the results gained a nitrate adsorption about 4.28 mg/g at pH = 3 condition. Sorption mechanism of nitrate on CTAC modified AC was investigated through two kinetic modellings including pseudo-second-order and Weber and Morris intra-particle diffusion model. The results imply that the generalized kinetic models tally well with experimental data. Additionally, interference of co-existing anions is examined, and the results showed that higher co-anions concentration would bring a heavier depression of the nitrate uptake due to its competing for adsorption sites. [ABSTRACT FROM AUTHOR]

Published
2020
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40. Two-phase integrated sludge thickening and digestion (TISTD) reactor microbial diversity and community structure succession rules

Author

He Qiang, Gu Li, Ai Hainan, and Sun Xingfu

Subjects
Sewage, Physiology, Ecology, Microbial diversity, Community structure, General Medicine, Ecological succession, Sequence Analysis, DNA, Biology, Pulp and paper industry, Applied Microbiology and Biotechnology, Biota, DNA, Ribosomal, Coenzyme F420, chemistry.chemical_compound, Bioreactors, chemistry, Microbial population biology, Phase (matter), RNA, Ribosomal, 16S, Cluster Analysis, Thickening, Digestion, Phylogeny, Biotechnology
Abstract

A two-phase integrated sludge thickening and digestion (TISTD) reactor composed of an inner and an outer reactor was developed. Acidification of natural organic material was the primary process in the outer reactor, whilst methane production was the dominant bioreaction occurring in the inner one. The special structure of TISTD thus enables the effective separation of the acid production phase and methane production phase during sludge processing. Molecular biological technology, including 16S rRNA gene and PCR-TGGE, was utilized to investigate the overall microbial community structure and diversity, as well as the processes of dynamic change. Analysis was also conducted on succinate dehydrogenase and coenzyme F420 change trends at each dosing ratio. The microbial community structure of the system exhibited disorder gradually and led to collapse when the dosing ratio increased above 30 %.

Published
2014

44. Pollutant concentrations and pollution loads in stormwater runoff from different land uses in Chongqing

Author

Shumin Wang, Zhentao Wang, Qianqian Zhang, Qiang He, and Ai Hainan

Subjects
Pollution, Pollutant, Hydrology, China, Environmental Engineering, Geography, media_common.quotation_subject, Rain, Chemical oxygen demand, Stormwater, Water Pollution, Environmental engineering, General Medicine, Environmental Chemistry, Cities, Water pollution, Surface runoff, Surface water, Water Pollutants, Chemical, General Environmental Science, media_common, Total suspended solids, Environmental Monitoring
Abstract

To investigate the distribution of pollutant concentrations and pollution loads in stormwater runoff in Chongqing, six typical land use types were selected and studied from August 2009 to September 2011. Statistical analysis on the distribution of pollutant concentrations in all water samples shows that pollutant concentrations fluctuate greatly in rainfall-runoff, and the concentrations of the same pollutant also vary greatly in different rainfall events. In addition, it indicates that the event mean concentrations (EMCs) of total suspended solids (TSS) and chemical oxygen demand (COD) from urban traffic roads (UTR) are significantly higher than those from residential roads (RR), commercial areas (CA), concrete roofs (CR), tile roofs (TRoof), and campus catchment areas (CCA); and the EMCs of total phosphorus (TP) and NH3-N from UTR and CA are 2.35-5 and 3 times of the class-II standard values specified in the Environmental Quality Standards for Surface Water (GB 3838-2002). The EMCs of Fe, Pb and Cd are also much higher than the class-III standard values. The analysis of pollution load producing coefficients (PLPC) reveals that the main pollution source of TSS, COD and TP is UTR. The analysis of correlations between rainfall factors and EMCs/PLPC indicates that rainfall duration is correlated with EMCs/PLPC of TSS for TRoof and TP for UTR, while rainfall intensity is correlated with EMCs/PLPC of TP for both CR and CCA. The results of this study provide a reference for better management of non-point source pollution in urban regions.

Published
2013

46. Effect of flow rate on growth and oxygen consumption of biofilm in gravity sewer.

Author

Xu, Jingwei, Li, Muzhi, He, Qiang, Sun, Xingfu, Zhou, Xiangren, Su, Zhenping, and Ai, Hainan

Subjects
SEWERAGE, BIOFILMS, POROSITY, AEROBIC capacity, OXYGEN consumption
Abstract

The function of sewer as reactors must rely on the biofilm in it. In this paper, the formation, structure, oxygen transfer, and activity of the biofilm under different hydraulic conditions were studied by the microelectrode technology, oxygen uptake rate (OUR) technology, and 454 high-throughput pyrosequencing technology. Results showed that when the wall-shear stresses were 1.12, 1.29, and 1.45 Pa, the porosity of the steady-state biofilm were 69.1, 64.4, and 55.1 %, respectively. The maximum values of OUR were 0.033, 0.027, and 0.022 mg/(L*s), respectively, and the COD removal efficiency in the sewers reached 40, 35, and 32 %, respectively. The research findings had an important significance on how to improve the treatment efficiency of the sewers. [ABSTRACT FROM AUTHOR]

Published
2017
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