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.

Organic matter was increased due to the input of plant litter, resulting in changes in the physicochemical properties and enhancement of greenhouse gas (GHG) emissions in water bodies. There are few reports on effects of decomposition of aquatic plants on GHGs emissions. This study investigated the effects of the degradation of two aquatic plants, Potamogeton crispus and Typha orientalis Presl, upon release of CO₂ and CH₄ at the sediment–water interface. During early decomposition, the release of CO₂ and CH₄ at the sediment–water interface was increased by the degradation of the two aquatic plants, and release flux of CO₂ and CH₄ were increased rapidly at first and then decreased. Due to the differences in properties of C, lignin, cellulose and other components of the plants, the Potamogeton crispus group obtained higher abundance of genes relevant to CO₂ and CH₄ metabolism, which leads to the increase of CO₂ and CH₄ emissions compared with that of the Typha orientalis Presl. In addition, dissolved oxygen and pH were decreased due to the decomposition of organic matter in the plant residues at the sediment–water interface, resulting in growth of anaerobic microorganisms. The increase of the relative abundance of anaerobic microorganisms promoted the decomposition of organic matter in the sediment and the enhancement of cell respiration, promoting the release of CH₄ and CO₂ during the decomposition of aquatic plants.

Pesticide adjuvants (PAs) are important components of pesticide. Nonetheless, limited information is available regarding their toxic effects on biota in terrestrial ecosystem. In the present study, the mortality, growth inhibition ratio, and avoidance behavior of Eisenia fetida were examined to investigate the ecotoxicological effects of toluene, xylene, and trichloroethylene and further their mixture. The 24 h median lethal concentration (24 h-LC₅₀) of the three PAs were 300.23, 1190.45, and 5332.36 mg/kg, and the 48 h-LC₅₀ values were 221.62, 962.89, and 4522.41 mg/kg, respectively. The mixture exhibited significant synergistic effect on the E. fetida. There was significant growth inhibition on E. fetida by the tested PAs. The avoidance threshold values of E. fetida for the tested PAs were 1100 mg/kg, 250 mg/kg, 5000 mg/kg, and 25% of the mixture, respectively. The results evaluated the toxic effects of the three PAs and their mixture on E. fetida, provided a basis for ecotoxicological risk assessment of PAs in the soil ecosystem.

Pesticide adjuvants (PAs) denote the general term for auxiliaries in pesticide preparations except for the active components. Toluene, chloroform, and trichloroethylene are the three most commonly used PAs as organic solvents. The residues of the three chemicals in the process of production and application of pesticides may endanger the ecosystem. In the present study, the mutagenicity of toluene, chloroform, and trichloroethylene as well the mixture of the three chemicals was tested by the Salmonella typhimurium reverse mutation test (Ames test) with TA97, TA98, TA100, and TA102 strains in the system with and without rat liver microsomal preparations (S9). The four tester strains have been used for more than 40 years to detect mutagenic compounds in chemicals, cosmetics, and environmental samples. The mutagenicity was detected on tester strains in the separated experiment from the three chemicals. The addition of S9 decreased the mutation ratios of toluene to four strains, except for the TA100 strain, but increased the mutation ratios of chloroform to four strains except for the TA98 strain. Trichloroethylene caused positive mutagenicity to become negative on the TA102 strain. In the mixed experiment, positive effects were detected only on the TA102 strain in the absence of S9. The addition of S9 increased the mutagenicity except for the TA102 strain. The mixture of toluene, chloroform, and trichloroethylene showed antagonism in mutagenicity to tester strains, except for the TA102 strain without S9. However, the mixture showed a synergistic effect to tester strains after adding S9 except for the TA98 strain.