In order to improve the management level of the environment technology,trial work of compiling a batch of best available techniques(BATs) guidelines were initiated in China in the Eleventh Five-year Plan Period.The current development of BATs in China showed that the investigation work was large,the technical information collected was not comprehensive,it lacked the innovative technologies promotion mechanism,the BATs screened out could not effectively guide the direction of the technology development.The implications of BATs in European Union(EU),the role of BAT reference documents,the implementation process and the information exchange mechanism were analyzed in detail.The role of BATs in laws and regulations,the sources of the technical information,the screening methods of BATs and the incentive mechanisms for innovative technologies in EU were summed up.It was pointed out that,in order to achieve the technology support of BAT for the environmental management,the legal basis for the application of BAT system,the technical information exchange platform,the technical working groups and the expert groups,and the verification mechanism to promote the development of new technologies should be established urgently in China.

Base on the practical operation data, the analysis of the bleaching agent consumption, the reed pulp quality, the reed pulp physical index and the wastewater pollutant with or without xylanase pretreatment in one reed pulp plant were done. The results showed that the per unit bleaching agent consumption could be reduced sharply, one hypochlorite bleaching could be cut down, the pulp brightness stability was enhanced, the reed pulp quality index of drainage, fragility and physical strength could be improved and the pollutant of the bleaching wastewater could be cut down when producing the same brightness reed pulp with xylanase pretreatment under the unchanging operation parameters. It is a practical bleaching process with which the pulp production cost could be decreased and the water environment could be preserved.

In order to promote the field test assessment and improve the environmental technology assessment in China, the problems of current environmental technology management system were deeply analyzed, and the role of field test assessment in the environmental technology assessment discussed. It was pointed out that the field test assessment was indispensable for performing best availability technology (BAT) assessment and environmental technology verification (ETV). Also, the field test assessment could accelerate incubation of new technologies, and promote environmental technology industrialization. The field test assessment was the key approach to build the environmental technology assessment system, and to improve the environmental technology assessment management level in China.

As national requirements of industrial energy conservation and emission reduction becomes more and more strict,the printed circuit board (PCB) industry has to solve the environmental treatment problems before better development.The main pollution sources and treatment status of PCB industry,i.e.the treatment status of PCB wastewater,waste etchant and sludge containing copper,were analyzed.The environmental technology requirements of this industry were put forward,including the wastewater treatment technologies for wastewater containing complex state copper,small and mid-sized enterprise wastewater,and PCB wastewater deep treatment and reuse,the waste etchant technologies in regenerating and recycling,and the recycling,stabilization and harmlessness technologies for the sludge containing copper.Suggestions on better solving the environmental problems and health development of this industry were put forward.

The water quality and concentrations of heavy metals including As,Ni,Pb,Cd,Cu,Zn,Cr,and Hg in surface sediments at eight monitoring sections of the Dongjiang River's main stream,its tributaries,and the Dongguan Canal downstream were examined.The index of geo-accumulation and potential ecological risk evaluation methods were used to evaluate the potential ecological risk of heavy metal pollution downstream of the Dongjiang River.The results show that heavy metals had accumulated in the surface sediments downstream of the Dongjiang River.The enrichment extent of Cd,according to the index of geo-accumulation,was very intense,the enrichment extent of Hg was moderate,and that of Cu and Zn was moderate in the main stream but intense in the tributaries and the Dongguan Canal.The potential ecological risk assessment shows that the ecological risk index was close to or greater than 300 downstream of the Dongjiang River,including the main stream,tributaries,and the canal,indicating that the total potential ecological risk caused by heavy metals was severe.Cd,Hg,and Cu were the main heavy metals contributing to the potential ecological risk,and their hazard ratings were in the following descending order: Cd,Hg,and Cu.The results from water quality monitoring show that the water quality downstream of the Dongjiang River was worrying during the dry period,when the concentration of Hg exceeded the Class Ⅲ standard of the Environmental Quality Standards for Surface Water.