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本研究では1) 化粧品におけるポリフルオロアルキルリン酸エステル類 (PAPs) の存在実態の把握, 2) 下水処理場におけるPAPsの挙動の検討, 3) 化粧品由来のPAPsの流入負荷量の推定を目的とした。国内外の化粧品を23製品購入し, 2016年8月に5ヶ所の下水処理場を調査した。化粧品中のΣ3 diPAPs (6:2diPAP, 6:2/8:2diPAP, 8:2diPAP) は1, 030～58, 500, 000 ng g-wet⁻¹ であった。下水処理場におけるΣ3 diPAPsの濃度は最初沈殿汚泥で479 ng L⁻¹, 返送汚泥で269 ng L⁻¹ であり, その負荷量は生物反応槽前後で減少する傾向が示された。化粧品由来のΣ3 diPAPsの流入負荷量は67～1, 180 mg day⁻¹ であり, その流入負荷率は14±2％を占め, 化粧品由来のPAPsの負荷割合が明らかになった。The main objectives of this study were to investigate 1） the occurrence of polyfluoroalkyl phosphate esters （PAPs） in cosmetics and 2） the behavior of PAPs in wastewater treatment plants （WWTPs） and 3） to estimate of the inflow load contributed by cosmetics. Cosmetic samples （n =23） were purchased in Japan and other countries, and field surveys in WWTPs （n =5） were conducted in August 2016. The total concentration of three types of diPAPs （6:2diPAP, 6:2/8:2diPAP, 8:2diPAP） detected in cosmetics were in the range of 1, 030 to 58, 500, 000 ng g-wet⁻¹. Fourteen diPAPs were detected in cosmetic samples by liquid chromatography mass spectrometry （LC-MS/MS）. The concentrations of the three diPAPs were 479 ng L⁻¹1 in primary sedimentation tank sludge, 123 ng L⁻¹ in biological reaction tank effluent, and 269 ng L⁻¹ in return sludge. The total mass of the three diPAPs decreased in the biological reaction tank. The inflow load contributed by cosmetics was estimated from information on amount to use and population. The inflow load of Σ3 diPAPs ranged from 67 to 1, 180 mg day⁻¹, which contributed 14±2% of the total load. The findings reported in this study suggested that special attention should be paid to the above kinds of new emerging pollutants.

In the first half of this paper, we describe applicability of the one-dimensional analytical modelof channel process with bank erosion, which was developed in the previous paper2), and a theoreticalconsideration of the stability of channel process by the use of fundamental equations of flow andsedimentation. From comparison between the analytical results and experimental ones undervarious flow and boundary conditions as shown in Table 1, it was concluded that the one-dimensio-nal analytical model is applicable to an uniform and a nonuniform channel widening processwithout meandering pattern by the use of a modified expression of sediment supply due to bankerosion and an assumption on criteria of channel widening at initiation of bed degradation. Theresults of the stability analysis show that the sediment supply due to bank erosion gives no seriousinfluence upon the stability of channel process in the case of the present experiment.In the second half, geometrical and kinematical characteristics of bars in alluvial channels anddevelopment of meandering are discussed on the basis of experimental results. As relationshipsamong width (B), length (LB), height (ZB) and migration velocity (VB) of bars, LB∝B and ZB∝LBwere obtained from those observed here and by other investigators in various alluvial channels andrivers, and VB∝QBLB-2 was derived by the use of the above relations and an expression ofsediment transport rate QB∝BZBVB. Furthermore, relationship on wave length of self-formendmeandering channel to flow discharge was derived in consideration of development and migrationof bars at a given point in the channel and relation between flow and sediment transport rate.

In the first half of this paper, we describe applicability of the one-dimensional analytical modelof channel process with bank erosion, which was developed in the previous paper2), and a theoreticalconsideration of the stability of channel process by the use of fundamental equations of flow andsedimentation. From comparison between the analytical results and experimental ones undervarious flow and boundary conditions as shown in Table 1, it was concluded that the one-dimensio-nal analytical model is applicable to an uniform and a nonuniform channel widening processwithout meandering pattern by the use of a modified expression of sediment supply due to bankerosion and an assumption on criteria of channel widening at initiation of bed degradation. Theresults of the stability analysis show that the sediment supply due to bank erosion gives no seriousinfluence upon the stability of channel process in the case of the present experiment.In the second half, geometrical and kinematical characteristics of bars in alluvial channels anddevelopment of meandering are discussed on the basis of experimental results. As relationshipsamong width (B), length (LB), height (ZB) and migration velocity (VB) of bars, LB∝B and ZB∝LBwere obtained from those observed here and by other investigators in various alluvial channels andrivers, and VB∝QBLB-2 was derived by the use of the above relations and an expression ofsediment transport rate QB∝BZBVB. Furthermore, relationship on wave length of self-formendmeandering channel to flow discharge was derived in consideration of development and migrationof bars at a given point in the channel and relation between flow and sediment transport rate.