Japan Institute of Wastewater Engineering Technology

Chitosan hydrogels are effective wound dressings that promote healing through the synergy of chitosan’s inherent biological properties and the moist environment they maintain. We previously developed hydrogel microparticles using a highly biocompatible chitosan derivative with superior therapeutic effects. This study aimed to enhance their clinical translation for Endoscopic Sinus Surgery (ESS) by optimizing preparation conditions to achieve an extrusion force of <20 N, facilitating ergonomic, single-handed administration by surgeons. While reducing the particle size alone was insufficient to lower the extrusion force significantly, the introduction of a mechanical “kneading” process to de-agglomerate microparticle aggregates resulted in a substantial reduction in the required force from 213 ± 80 N to approximately 47 N. By further optimizing the polymer concentration to 5.0% (w/v), we successfully reduced the maximum extrusion force to below 20 N (17 ± 1 N). These results demonstrate that the optimized injectable chitosan gel microparticles achieve the practical usability required for precise surgical maneuvers during ESS.

Antipsychotics are widely used for neuropsychiatric symptoms (NPSs) in dementia including Alzheimer's disease (AD), yet balancing efficacy and safety remains a major clinical challenge. Relevant randomized controlled trials were identified through a comprehensive literature search of CENTRAL, PubMed, CINAHL, and ClinicalTrials.gov. We conducted a dose-response model-based network meta-analysis to evaluate the efficacy as the change in overall NPS severity and the tolerability as treatment discontinuation due to adverse events of aripiprazole, brexpiprazole, risperidone, quetiapine and olanzapine at varying doses in patients with dementia including AD. Twenty trials involving 5844 participants were included. Most of the included antipsychotics exhibited a generally positive dose-response relationship with respect to both efficacy and tolerability, except for olanzapine, which showed a bell-shaped curve in terms of efficacy. Only aripiprazole 10 mg, brexpiprazole 1-2.5 mg, risperidone 1-2 mg, and olanzapine 2.5-5 mg were significantly more effective than placebo. Tolerability did not significantly decrease compared to placebo for aripiprazole up to 10 mg, brexpiprazole up to 3 mg, risperidone up to 1 mg, olanzapine up to 2.5 mg and at 15 mg, and quetiapine up to 200 mg. Furthermore, significant differences in efficacy and tolerability were observed between certain doses of several antipsychotics. Aripiprazole 10 mg, brexpiprazole 1-2.5 mg, risperidone 1 mg, and olanzapine 2.5 mg were both effective and well tolerated, indicating their potential as favorable treatment options. As the present model incorporates several sources of uncertainty, its findings should be interpreted with caution and regarded as a provisional framework to support clinical decision-making.

Liquid-solid two-phase fluidized bed type reactor was operated for struvite recovery for the purpose of developing the reactor that can be applied to wastewater having low PO4-P concentrations. In area-wide sewage sludge treatment plant, the reactor was examined to recover struvite from thickener effluent, whose PO4-P concentration was around 40 mg/L. When the thickener effluent was treated by the reactor without the addition of Mg2+, Ca2+ affected struvite recovery and the Ca contents of the recovery particles increased. In batch tests, it was confirmed that the condition where struvite precipitates prior to calcium phosphate in wastewater requires the condition of [Ca2+]/[Mg2+] < 0.25 in the influent. The inorganic SS flowing into the reactor was also found to affect the recovery in column tests. To prevent this effect by the inorganic SS, the reactor was operated without the influent of fine suspended solids in the wastewater from the melting furnace. The only influent processed was the thickener effluent, and MgCl2 aq. was added using a magnesium resource. Consequently, the recovery rate improved to 62%. In the case that struvite is recovered from wastewater including low PO4-P concentration, the recovery rate of struvite was affected by the coexistent substances in the influent. But if this effect was controlled, this reactor could recover struvite particles passably.

The progress of urbanization has brought a dramatic increase in non-porous surfaces that has caused higher rainwater runoff coefficients. As a result the amounts of rainwater flowing into sewerage systems have become larger. At the same time, problems have arisen for rainwater elimination planning, such as the occurrence of short-duration and localized rainfall in amounts far exceeding expectations. This means that large cities which early framed rainwater elimination plans and moved ahead with rainwater facility provision, are now experiencing difficulty in achieving flood control safety with their initially-planned rainwater facility provision target levels.

In Japan, a combined sewerage system was first introduced to big cities. Because part of untreated wastewater is discharged from a combined sewerage system to public waters on rainy days, there is concern that such untreated wastewater could cause water pollution and other unfavorable effects. To prevent the overflow of untreated wastewater or combined sewer overflow (hereafter called CSO), various countermeasures have been taken until now: increasing the number of water retention pipes and intercepting sewers, improving retention reservoirs, etc. Because such countermeasures cost a great deal and involve extensive work and long work periods, simpler, more effective means to reduce CSO are required. The Japan Institute of Wastewater Engineering Technology (hereafter called JIWET) conducted research on a high-speed, space-saving fiber filter as a means to reduce discharge load and evaluated its practical performance and applicability to a combined sewerage system. Although this fiber filter has track records in industrial water and wastewater treatment and secondary treatment domestic wastewater filtration, it has never been used to process primary treatment wastewater. The results of conducted research show that a high-speed fiber filter can be used to decrease the amount of primary treatment wastewater overflow (overflow water from the first settling basin) on rainy days and that of secondary treatment wastewater overflow on fine days.

Method for measurement of the density of watercourses is developed to know whether people have watercourses in their neighborhood or not.Meshes of 500m*500m unit size are set on Iriegawa-Takinokawa basin in Yokohama city, and measurement of the length of watercourses per unit mesh is performed.Meshes are divided into four grades; A (0m/ha), B (0-10), C (10-20), D (more than 20), and classified as shown in Fig. 2.Most of meshes in Fig.2 are ranked A or B (under 0-10m/ha), and people in these meshes have scarce watercourses in their neighborhood.Renovation of the buried streams and ponds is necessary in these areas.