Spatial and seasonal variations of particulate phosphorus (PP) in a large shallow, eutrophic Lake Taihu with different ecotypes (including a phytoplankton-dominated zone, lake center zone, estuary zone and macrophyte-dominated zone) were investigated. The results showed that particulate organic phosphorus (POP) was the dominant form of PP (>88.0%). The concentration of POP showed higher levels in the bloom-sensitive northwestern zone (phytoplankton-dominated zone and estuary zone) during warm seasons, phytoplankton blooms and input of exogenous particulate matter were the main sources of POP in the lake water. Based on ³¹P nuclear magnetic resonance (³¹P NMR) analysis, orthophosphate (Ortho-P) was the dominant molecular species of PP and positively correlated with soluble reactive phosphorus (SRP) (p < 0.01). This suggested that the release of Ortho-P from suspended particulate matter (SPM) was the main source of SRP in the lake water. Pyrophosphate (Pyro-P), which is regarded as a highly labile species of P compounds, represented a large fraction of PP, and its significant positive correlations with chlorophyll a (Chl a), indicated that the concentration of Pyro-P could be used as an important indicator for the degree of eutrophication of Lake Taihu. These results proved that PP in lake water was a significant factor supporting lake eutrophication and must be controlled.

Increasing attention has been given to the treatment of livestock and poultry wastewater because of its high ammonium nitrogen (NH₄⁺-N) content and low carbon/nitrogen ratio (C/N). Ceramic filter medium (CFM) and dewatered aluminum sludge (DAS), which are products from cast-off materials, are used as small-scale combined biological filters (CFM-DAS) for wastewater treatment. The high and stale removal efficiency of chemical oxygen demand (COD), NH₄⁺-N, and total nitrogen (TN) in the DAS filter indicate that DAS plays a major role in pollutant removal. Although significant differences are found between the composition of nitrifying bacteria in CFM and DAS, the structures of nitrifying communities are evenly distributed in each layer of CFM or DAS irrespective of the running time. Microbial compositions are attributed to the comprehensive effect of various environmental factors such as pH and TN at effluents. In the DAS, Nitrosospira shows significant negative correlation with the concentrations of NH₄⁺-N in effluents, whereas it has positive correlation with NO₃⁻-N, and Nitrososphaera has a significant negative correlation with NO₃⁻-N in effluents. Pearson correlation test reveals that certain genera may be used in estimating or predicting NH₄⁺-N consumption and NO₃⁻-N accumulation in CFM-DAS for treating sewage with a high NH₄⁺-N content.