Using polyaluminium chloride (PAC) and chitosan as the main coagulant and coagulant-aid respectively, the high algae-laden water was treated by coagulation/flocculation/dissolved air flotation (C/F/DAF). When the doses of PAC and chitosan were both moderate (7.0~8.4 mg Al2O3/L of PAC and 0.6~1.0 mg/L of chitosan), the removal rates of turbidity, algae cells and TOC were all increased apparently compared with adding PAC alone. Especially, the residual aluminum concentration reduced significantly in treated water with the aid of chitosan. The structrue and strength of flocs formed by coagulation aid of chitosan were improved obviously, which proved that addition of chitosan could enhance the flocculation performance of PAC. So, in C/F/DAF process for removing algae, using chitosan as coagulant-aid can improve the flotation performance and reduce residual aluminum concentration in treated water.

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Beijing-Tianjin-Tangshan- Qinhuangdao area structurally lies in the fault-fold belt before Yanshan orogenic belt. The geothermal springs are divided into two types: the natural outcrop type and the hidden artificial type of heat reservoir, the former of which is controlled by piedmont faulted , extending EW; while the latter of which is controlled by regional structure and geothermal field. Geothermal spring water is low salinity and neutral even low alkaline water, whose chemical type is mainly SO4•HCO3- Na and SO4•Cl•HCO3- Na. As the water is rich in fluoride and multiple heavy metals, it pollutes drinking water, soil, crops in different degree during the development and utilization. H2S and CO2 in the geothermal water also does harm to the atmosphere more or less.

This experiment extracted a halophilic bacteria from the deep sea-bed mud to carry out bioremediation of PCB-contaminated soil under different nitrogen source, permeability, humidity, temperature and salinity. The experimental results showed that during the 20-day soil natural bioremediation, there were little change in the concentration of PCB1260. The PCBs degradation rate was 26.03% in 20d when the soil water content was 60% of field capacity, room temperature, beef extract 0.5g•kg-1, standing, soil salinity 0.2g•kg-1. When the soil temperature increased to 30°C, the PCBs degradation rate was up to 89.21%. After submerging treatment, the degradation rate was 19.45% in 20d. Adding nitrogen-contained nutrition and proper soil stirring aided the growth of B2.6, enhanced the metabolic activities of indigenous microorganisms, and accelerated the natural degradation of soil PCBs. The PCBs degradation rate was up to 38.97% when the soil salinity was 1g•kg-1.

A salt-tolerant PCBs degrading strain B2.6 which can use PCBs as the sole carbon source and energy was isolated from the deep sea sediments of southern Yellow Sea. It was identified as Vibrio splendidus, according to morphological, physiological and biochemical characteristics and 16SrDNA sequence analysis. The experimental results suggested that the optimum conditions for the degradation of PCBs are temperature 30°C, pH 7 to 8, the concentration of NaCl was 150g•L-1. Under the optimum conditions, the PCBs degradation could reach 98.27% in 72h which concentration was below 0.6mg•L-1. The genome was amplified with bacterium 16SrDNA primer. The amplified product was purified and sequenced forphylogenetic analyses with Genbank. The bacterium B2.6 was identified as Vibrio splendidus. RAPD analyses of B2.6 produced stable DNA fingerprint. These studies have provided parameter for the further dynamic resolution of bacterium clusters for the rehabilitation of PCBs contaminated underground water environment with B2.6 PRB method.