开展生物法处理金矿含氰废水同步收金技术研究,通过改良缺氧^(-)好氧生物处理工艺,成功驯化增殖了以硫杆菌、特吕珀菌、假单胞菌为主的CN^(-)、SCN^(-)高效降解菌群。在工业应用上,生物法对SCN^(-)、COD、CN^(-)、NH_(3)-N的平均去除率...开展生物法处理金矿含氰废水同步收金技术研究,通过改良缺氧^(-)好氧生物处理工艺,成功驯化增殖了以硫杆菌、特吕珀菌、假单胞菌为主的CN^(-)、SCN^(-)高效降解菌群。在工业应用上,生物法对SCN^(-)、COD、CN^(-)、NH_(3)-N的平均去除率分别为99.99%、97.54%、93.92%和98.92%,处理后的出水各项污染物指标远低于《污水综合排放标准》(GB 8978—1996)一级标准。微生物在降解废水污染物的同时,通过自身的氧化、吸附、絮凝沉降等作用,对起始浓度低的混合含金废水进行金回收,金的回收率可达到91%,富集金品位300~400 g t,不仅深度处理了废水中各项污染物,同时回收了有价金属,是一种环境友好且无公害的含氰废水处理技术。展开更多
Ammonia-oxidizing archaea （AOA） are widely considered key to ammonia oxidation in various environments. However, little work has been conducted to simultaneously investigate the abundance and diversity of AOA as wel...Ammonia-oxidizing archaea （AOA） are widely considered key to ammonia oxidation in various environments. However, little work has been conducted to simultaneously investigate the abundance and diversity of AOA as well as correlations between archaeal amoA genotypes and environmental parameters of different ecosystems at one district. To understand the abundance, diversity, and distribution of AOA in Pearl River Delta of China in response to various habitats, the archaeal amoA genes in soil, marine, river, lake, hot spring and wastewater treatment plant （WWTP） samples were investigated using real-time fluorescent quantitative PCR and clone libraries. Our analyses indicated that the diversity of AOA in various habitats was different and could be clustered into five major clades, i.e., estuary sediment, marine water/sediment, soil, hot spring and Cluster 1. Phylogenetic analyses revealed that the structure of AOA communities in similar ecological habitats exhibited strong relation. The canonical correspondence method indicated that the AOA community structure was strongly correlated to temperature, pH, total organic carbon, total nitrogen and dissolved oxygen variables. Assessing AOA amoA gene copy numbers, ranging from 6.84× 10^6 to 9.45 × 10^7 copies/g in dry soil/sediment, and 6.06× 10^6 to 2.41 ×10^7 copies/L in water samples, were higher than ammonia-oxidizing bacteria （AOB） by 1-2 orders of magnitude. However, AOA amoA copy numbers were much lower than AOB in WWTP activated sludge samples. Overall, these studies suggested that AOA may be a major contributor to ammonia oxidation in natural habitats but play a minor role in highly aerated activated sludge. The result also showed the ratio of AOA to AOB amoA gene abundance was positively correlated with temperature and less correlated with other environmental parameters. New data from our study provide increasing evidence for the relative abundance and diversity of ammonia-oxidizing archaea in the global nitrogen cycle.展开更多
The aim of this work is to identify the range of applicability of Arrhenius type temperature dependence for Ammonia Oxidizing Bacteria （AOB） subjected to tem- perature time gradients through continuous titrimetric t...The aim of this work is to identify the range of applicability of Arrhenius type temperature dependence for Ammonia Oxidizing Bacteria （AOB） subjected to tem- perature time gradients through continuous titrimetric tests. An innovative online differential titrimetric technique was used to continuously monitor the maximum biologic ammonia oxidation rate of the biomass selected in a pilot scale membrane bioreactor, as a function of temperature time gradients. The monitoring technique is based on the measurement of alkalinity and hydrogen peroxide con- sumption rates in two parallel reactors operated in non- limiting substrate conditions for AOB; both reactors were continuously fed with mixed liquor and in one of them AOB were inhibited with allylthiourea. The effects of temperature decrease rates in the range 1 to 4℃h^-1 were evaluated by controlling the titrimetric reactor in the temperature range 10℃-20℃. The dependence of growth kinetics on temperature time gradients and the range of applicability of Arrhenius model for temperature depen- dency of AOB growth kinetics were assessed. The Arrhenius model was found to be accurate only with temperature gradients lower than 2℃·h^-1. The estimated Arrhenius coefficients （θ） were shown to increase from 1.07 to 1.6 when the temperature decrease rate reached 4℃.h^-1.展开更多
文摘开展生物法处理金矿含氰废水同步收金技术研究,通过改良缺氧^(-)好氧生物处理工艺,成功驯化增殖了以硫杆菌、特吕珀菌、假单胞菌为主的CN^(-)、SCN^(-)高效降解菌群。在工业应用上,生物法对SCN^(-)、COD、CN^(-)、NH_(3)-N的平均去除率分别为99.99%、97.54%、93.92%和98.92%,处理后的出水各项污染物指标远低于《污水综合排放标准》(GB 8978—1996)一级标准。微生物在降解废水污染物的同时,通过自身的氧化、吸附、絮凝沉降等作用,对起始浓度低的混合含金废水进行金回收,金的回收率可达到91%,富集金品位300~400 g t,不仅深度处理了废水中各项污染物,同时回收了有价金属,是一种环境友好且无公害的含氰废水处理技术。
基金supported by the National Natural Science Foundation of China (No. 50978069)
文摘Ammonia-oxidizing archaea （AOA） are widely considered key to ammonia oxidation in various environments. However, little work has been conducted to simultaneously investigate the abundance and diversity of AOA as well as correlations between archaeal amoA genotypes and environmental parameters of different ecosystems at one district. To understand the abundance, diversity, and distribution of AOA in Pearl River Delta of China in response to various habitats, the archaeal amoA genes in soil, marine, river, lake, hot spring and wastewater treatment plant （WWTP） samples were investigated using real-time fluorescent quantitative PCR and clone libraries. Our analyses indicated that the diversity of AOA in various habitats was different and could be clustered into five major clades, i.e., estuary sediment, marine water/sediment, soil, hot spring and Cluster 1. Phylogenetic analyses revealed that the structure of AOA communities in similar ecological habitats exhibited strong relation. The canonical correspondence method indicated that the AOA community structure was strongly correlated to temperature, pH, total organic carbon, total nitrogen and dissolved oxygen variables. Assessing AOA amoA gene copy numbers, ranging from 6.84× 10^6 to 9.45 × 10^7 copies/g in dry soil/sediment, and 6.06× 10^6 to 2.41 ×10^7 copies/L in water samples, were higher than ammonia-oxidizing bacteria （AOB） by 1-2 orders of magnitude. However, AOA amoA copy numbers were much lower than AOB in WWTP activated sludge samples. Overall, these studies suggested that AOA may be a major contributor to ammonia oxidation in natural habitats but play a minor role in highly aerated activated sludge. The result also showed the ratio of AOA to AOB amoA gene abundance was positively correlated with temperature and less correlated with other environmental parameters. New data from our study provide increasing evidence for the relative abundance and diversity of ammonia-oxidizing archaea in the global nitrogen cycle.
文摘The aim of this work is to identify the range of applicability of Arrhenius type temperature dependence for Ammonia Oxidizing Bacteria （AOB） subjected to tem- perature time gradients through continuous titrimetric tests. An innovative online differential titrimetric technique was used to continuously monitor the maximum biologic ammonia oxidation rate of the biomass selected in a pilot scale membrane bioreactor, as a function of temperature time gradients. The monitoring technique is based on the measurement of alkalinity and hydrogen peroxide con- sumption rates in two parallel reactors operated in non- limiting substrate conditions for AOB; both reactors were continuously fed with mixed liquor and in one of them AOB were inhibited with allylthiourea. The effects of temperature decrease rates in the range 1 to 4℃h^-1 were evaluated by controlling the titrimetric reactor in the temperature range 10℃-20℃. The dependence of growth kinetics on temperature time gradients and the range of applicability of Arrhenius model for temperature depen- dency of AOB growth kinetics were assessed. The Arrhenius model was found to be accurate only with temperature gradients lower than 2℃·h^-1. The estimated Arrhenius coefficients （θ） were shown to increase from 1.07 to 1.6 when the temperature decrease rate reached 4℃.h^-1.
