Based on the data collected from the British Geological Survey, European Pollutant Release and Transfer Register, China Statistical Yearbook on Environment, and Annual Statistic Report on Environment in China, the variations of metal production, regional and industrial distributions of heavy metals discharge from industrial wastewater were compared for China and European Union. Although the metal production increased quickly from 1993 to 2014, the total discharge of heavy metals in wastewaters decreased. This is ascribed to the change in production modes, technology innovation, and improvement of wastewater discharge standard. The regional and industry distributions of heavy metals in wastewaters were different for different heavy metals. Whereas, the regional and industrial distributions of heavy metal discharges from industrial wastewaters of European Union change insignificantly from 2007 to 2013. Moreover, the European Union’s experience in policy formulation and supervision will help China learn from it.

Landfill leachate was treated by A/O-coagulation-BDD combined processes, and the organic matters during treatment processes were characterized by UV spectra, fluorescence excitation-emission matrix, GC-MS, and Fourier transform infrared spectra under optimum operating conditions. Aliphatic organic matters, tryptophan-like matters, and some fulvic acid-like organic matters can be easily removed by A/O treatment while humic acid-like organic matters can not. The removal efficiencies of ryptophan-like matters and fulvic acid-like organic matters were better as HRT increasing from 4.0 d to 10.7 d. As sludge recirculation ratio increasing from 3.0 to 3.5, the removal efficiency of ryptophan-like matters was better while the removal efficiency of fulvic acid-like organic matters was worse. Coagulation mainly removed aliphatic organic matters, proteins, and some humic acid-like organic matters, but can’t easily remove fulvic acid-like organic matters, and there were still some aroma organic matter in the effluent. BDD treatment can effectively remove kinds of refractory organic matters.

Landfill leachate was treated by A/O-coagulation-BDD combined processes, and the operation parameters were optimized. The optimal HRT and sludge recirculation ratio was 10.7 days and 3.5 for A/O treatment process. Reaction pH and optimal dose of ferric chloride coagulation treatment was 5.5 and 0.4 g/L. The current density and A/V ratio (anode area/reaction volum) for best performance of BDD was 60 mA/cm² and 4 m^-1. COD_Cr concentration in raw leachte and final effluent were 13375 mg/L and 60 mg/L, with the removal efficiency of 99.5%. TOC concentration before and after treatment by combined treatment process were 6893 mg/L and 12 mg/L, with the removal efficiency of 99.8%. Ammonia nitrogen was completely removed by the combined treatment processes from 1889 mg/L to 0 mg/L. The contribution of A/O, coagulation, and BDD was 59.0%, 32.9%, and 7.6% for COD_Cr removal of total COD_Cr, was 50.5%, 46.1%, and 13.2% for TOC removal, was 84.3%, 2.5%, and 3.2% for ammonia nitrogen removal, respectively.