Switzerland is the primary “watershed of Europe.” The Swiss Alps feeds all major Central European rivers including the Rhône, Danube, Rhine and Po. The country also plays a very active international role in environmental affairs since many multinational organizations such as the United Nations, the International Union for Conservation of Nature and Natural Resources (IUCN) and the Ramsar Convention are based in Switzerland. In the present paper we give a brief overview of the water policy of Switzerland and provide selected examples of the state and trends of the water environment. The most fundamental principles in water management were formulated in the Water Protection Law in 1991 and subsequently updated in 1991. In it, the protection of groundwater and the maintenance of residual flow in rivers and streams were manifested. Ground water supplies 80 % of the total water consumption of the human population. Local authorities identify groundwater protection areas, and unpolluted wastewater such as storm water is also used to recharge the aquifer. Furthermore, minimum residual flows are calculated to maintain the ecological integrity of rivers and streams. Finally, we compare the Swiss situation with the water conservation policy in Japan.

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In order to remove phosphorus from domestic wastewater, enhanced biological phosphorus removal (EBPR) and the activated sludge process with coagulant addition have been widely used. According to the performance of phosphorus removal in actual existing facilities, it is considered possible to reduce the amount of coagulant added to the aeration tank by combining of the two processes. Therefore the dynamics of phosphorus and coagulants were investigated by examining three existing domestic wastewater treatment facilities. EBPR took place unintentionally in these facilities because of their denitrification operations. The unintentional EBPR was unstable and its performance was poor when denitrification was incomplete. An addition of coagulants to the unintentional EBPR facilities stabilized the performance. The coagulants moved to the activated sludge immediately after their addition. The content of the coagulants in the activated sludge decreased exponentially with a constant rate of 1/SRT after the ceasing of addition. The performacne of phosphorus removal continued to be high and stable while the coagulant content was remained high. Maintaining a high coagulant content of the sludge is effective to keep the performance of phosphorus removal. This indicated a new method of reducing the amount of coagulant addition.

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Sea urchins (fully mature: large, mature: medium and maturing: small) were cultured for 2 weeks in seawater containing nonylphenol (NP). The GT ratio (=100·gonad volume/test volume) was measured for all sea urchin samples that were then classified into five ranks. The grade of maturity of sea urchin gonads was also determined. The graded sea urchin gonads were fixed, sectioned and stained for microscopic observations. The results were compared in terms of size, sex and NP treatment concentration. The average GT ratio decreased with decreasing size, whereas it increased with increasing NP treatment concentrations. The grade of maturity was V or IV in large and medium female and male (probably) sea urchins in the control and treatment groups. The grade was under III in small ones ; the same result for both sexes was observed. On microscopic observation, the acceleration of gametogenesis was observed in treated sea urchins. Hermaphrodite (testis-ova) urchins were also observed.

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Based on the knowledge concerning the chemical reduction of NO₃-N in the presence of Fe²⁺ and Cu²⁺ as a catalyst at a high pH range, the feasibility of an Fe-rich converter slag for NO₃-N reduction in sediments was investigated. Components released from the slag were able to reduce NO₃-N chemically. Magnesia contained in the slag functioned as a substitute for Cu²⁺ which is hardly contained in the slag. The chemical reduction of NO₃-N was suppressed by phosphate. The major product of the chemical reduction of NO₃-N was NH₄-N, and the rates of formation of NO₂-N and N₂O-N were low. Biological reduction of NO₃-N was comparable to the chemical reduction in the sediment amended with the slag in the pH range from 8 to 9. The major product was also NH₄-N, but the denitrifying process became dominant with an increase in the biomass of denitrifiers. The release of NH₄-N and NO₂-N from the sediment amended with the slag was mainly due to chemical reduction of NO₃-N by the slag. Fe²⁺ and Mg²⁺ in sediments as well as those originated in the slag play a significant role in NO₃-N reduction.

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