Phosphorus dynamics associated with phytoplankton blooms in eutrophic Mikawa Bay,Japan

Changes in the phosphorus components of the particulate matter in seawater were studied in the eutrophicated waters of Mikawa Bay, Japan, during summer 1981. The contents of particulate phosphorus and hot-water extractable intracellular phosphorus displayed remarkable changes associated with phytoplankton blooms caused by wind-induced or upwelling-associated nutrient enrichment from the bottom water layers. Nanoplankton <10 m accounted for much of the particulate phosphorus (70 to 79% in June and July, and 44 to 78% in August and September); the contribution of large-sized phytoplankton >25 m varied from 9 to 49%, the peak values being attained under red-tide conditions. The capacity for phosphorus storage in cells was low in nanoplankton cells, high in large phytoplankton species. Differences in rates of phosphorus storage and growth between nanoplankton and large phytoplankton accounted for fluctuations in particulate phosphorus which were closely associated with fluctuations in phytoplankton blooms in Mikaw Bay.     

Fate estimation of estrogenic substances in an urban river by flux calculation.

This study investigated the fate of estrogenic substances in an urban river receiving discharge from wastewater treatment plants (WTPs) by flux calculation, focusing on the middle reaches of the Tama River in Tokyo, which is one of the most urbanized rivers in Japan. The level of estrogenic activity flux was almost negligibly small at the upstream station. The level was considerably raised after inflows from the WTPs and then the level declined in the lower reaches of the river. When contributions of estrogenic substances to estrogenic activity were estimated, estrone (E1) was the primary contributor to the total estrogenic activity in all the sampling stations, followed by estradiol (E2). The contribution of nonylphenol to estrogenic activity was small. The E1 and E2 accounted for approximately 90% or more of estrogenic activity in the Tama River. As for the total fluxes of the estrogenic substances in the study area in the Tama River, the proportion of flux associated with WTP discharge was approximately 100% of the total fluxes, and the effects of the tributaries flowing into the river were almost negligible. When the reduction ratios of estrogenic activity were calculated by the flux, the ratios were found to increase toward the lower reaches of the river. Similar changes were observed for E1. Meanwhile, the change of reduction ratios for E2 was different from that observed for estrogenic activity.     

Prenatal diagnosis of atelosteogenesis type I at 21 weeks' gestation

We describe prenatal diagnosis in a male fetus at 21 weeks of gestation with atelosteogenesis type I (AO I). Fetal ultrasonography (US) revealed absent or deficient ossification of the posterior neural arches of the thoracic spine, humeri, radii, ulnae, fibulae, and short tubular bones other than the distal phalanges, in addition to extremely short, thick femora. Fetal magnetic resonance imaging (MRI) using an ultrafast imaging sequence depicted dysmorphic features, pulmonary hypoplasia, and large cisterna magna. Postmortem radiographs warranted a diagnosis of AO I. Autopsy corroborated not only pulmonary hypoplasia but also laryngeal stenosis. The chondro-osseous histological findings were consistent with those of AO I. Meticulous evaluation using fetal US and MRI permits a definitive prenatal diagnosis of AO I to be made. Copyright © 2002 John Wiley & Sons, Ltd.     

Generation amount prediction and material flow analysis of electronic waste: a case study in Beijing, China.

The draft legislation on e-waste prepared by the Chinese national government assigns management responsibility to local governments. It is an urgent task for the municipal government to plan an effective system as soon as possible to divert the e-waste flow from the existing informal e-waste recycling processes. This paper presents a case study implemented in Beijing, the capital city of China, with the purpose of predicting the amount of obsolete equipment for five main kinds of electronic appliances from urban households and to analyse the flow after the end of their useful phase. The amount to be handled was 885,354 units in 2005 and is predicted to double by 2010. Due to consumption growth and the expansion of urbanization it is estimated that the amount will increase to approximate 2,820,000 units by 2020: 70% of the obsolete appliances will be awaiting collection for possible recycling, 7% will be stored at the owner's home for 1 year on average and 4% will be discarded directly and enter the municipal solid waste collecting system. The remaining items will be reused for about 3 years on average after the change of ownership. The results of this study will assist the waste management authorities of Beijing to plan the collecting system and facilities needed for management of e-waste generated in the near future.     

Oxygen intrusion into waste in old landfills of low organic content.

Oxygen invasion into old landfills was studied by assuming the installation of gas venting pipes to promote stabilization of waste. In an experiment using a column pack with old incombustible waste, oxygen intrusion was observed and the oxygen consumption rate was estimated. Oxygen diffused into the waste layer very quickly in the initial stage of the experiment, but oxygen concentration increased only gradually due to reduced gradient and decreasing oxygen consumption. The maximum oxygen consumption rate in packed waste was one-third of that in loosely deposited waste in a beaker measured in a respiration test. A mathematical model was created which fitted the experimental data well and a three-dimensional simulation of a full-scale landfill and a sensitivity analysis were performed.     

Degradation of phenol,Asulam and lignin in aqueous solution by Ozonation

Phenol, the herbicide asulam (methylsulfanilyl carbamate) and lignin were degraded by ozonation. The addition of Fe³⁺ did not affect the disappearance rates of phenol and asulam appreciably, whereas UV illumination accelerated the disappearance rate. Fe³⁺ under UV illumination showed only a slight effect on the disappearance rate, but a fairly large effect on TOC elimination. The degradation of the intermediate compounds of asulam including aromatic compounds and organic acids, under UV illumination was accelerated by the addition of Fe³⁺. A possible degradation process of asulam by ozonation was proposed on the basis of intermediate and final products identified.     

Tsunami mitigation by coastal vegetation considering the effect of tree breaking

Damage to vegetation by tsunami moment and reduction of potential tsunami force are discussed based on a numerical simulation. A numerical model based on two-dimensional nonlinear long-wave equations that include drag forces and turbulence-induced shear force due to the presence of vegetation was developed to estimate tree breaking. The numerical model was then applied to a coastal forest where two dominant tropical vegetation species, Pandanus odoratissimus and Casuarina equisetifolia, were considered. The threshold water depth for tree breaking increased with increasing forest width, and the analysis was consistent with the field investigation results that the critical tsunami water depth for breaking is around 80% of the tree height for P. odoratissimus. C. equisetifolia is stronger than P. odoratissimus against tsunami action, but P. odoratissimus can reduce a greater tsunami force than C. equisetifolia due to its complex of aerial root structures. Even if breakage occurs, P. odoratissimus still has high potential to reduce the tsunami force due to its dense aerial root structures. Previous numerical models that do not include the breaking phenomena may overestimate the vegetation effect for reducing tsunami force. The combination of P. odoratissimus and C. equisetifolia is recommended as a vegetation bioshield to protect coastal areas from tsunami hazards.     

Photodegradation characteristics of PPCPs in water with UV treatment

The degradation characteristics of PPCPs commonly found in surface water under UV treatment were examined for 30 kinds of PPCPs using a UV/Lamp1 that emits light at a wavelength of 254 nm and a UV/Lamp2 that emits light at 254 nm and 185 nm in pure water. When a UV dose of some 230 mJ/cm² was introduced to the 30 PPCPs, photodegradation rates of about > 3% (theophylline) to 100% (diclofenac) and about > 15% (clarithromycin) to 100% (diclofenac) were observed for UV/Lamp1 and UV/Lamp2, respectively. This study also showed that UV/Lamp2, which photolyzes water molecules and generates OH radicals, is more effective for PPCP removal than UV/lamp1. It was postulated that the degradation rates of sulfamethoxazole, sulfamonomethoxine, sulfadimethoxine and sulfadimidine, all, including sulfamethoxazole, derived from sulfanilamide, under UV/Lamp1 resulted mainly from the bond-breaking reactions occurring between –SO₂– and its side atoms, the C–S bond and the N–H bond. Some PPCPs with amide bonds, such as cyclophosphamide and DEET, were highly resistant to photodegradation by UV/Lamp1. AOPs (Advanced oxidation processes) such as the UV/H₂O₂ or UV/O₃ processes should therefore be considered for their potential to remove these substances effectively.     

Development of extraction method of pharmaceuticals and their occurrences found in Japanese wastewater treatment plants

In this study, occurrence of 66 PPCPs (pharmaceuticals and personal care products) in liquid and solid phases of sewage sludge was elucidated. The extraction methods for the PPCPs from sludge were newly developed employing Pressurized Liquid Extraction (PLE) and Ultrasonic Solvent Extraction (USE). As an appropriate method, PLE using water (pH2), PLE using methanol (pH4), and USE using mixture of methanol and water (1/9,v/v, pH11) was found most effective because total recovery of most of the PPCPs indicated 40 to 130%. The developed extraction method with previously developed method for liquid phase analysis was applied to field survey at wastewater treatment plants (WWTPs) in Japan. 56 compounds were detected from the primary sludge and 61 compounds were detected from the excess sludge. The concentration was ranged between several ng/g and several μg/g. Solid-water distribution coefficient (Log K_d) ranged between 0.9 L/kg (Caffeine) and 3.7 L/kg (Levofloxacin) for primary sludge and between 1.4 L/kg (Sulpirid) and 4.3 L/kg (Mefenamic acid) for excess sludge.