Palm oil mill effluent (POME) had acidic pH (pH 4.5) and high C/N ratio that was suitable for fungal treatment. Treatment of POME (15 − 51 g/L) by Humicola insolens D2, Thermomyces lanuginosus E4, and Rhizopus oryzae ST29 for 5 days indicated the optimum concentration of 22.5 g/L soluble COD. R. oryzae ST 29 was most efficient in removal of COD (60.0%), oil & grease (98.6%), and total solids (52.9%). The strain grew well (16.9 g-biomass/L) and also produced the highest biopolymer (26.9 mg/g biomass) with the simultaneous removal of solids from POME. The maximum treatment efficiency and enzyme production (814 U/mL CMCase and 1,550 U/mL xylanase) were achieved after 4 days cultivation. R. oryzae ST 29 was selected for optimization studies which revealed the supplementation of 0.025% fertilizer (46% urea) and the initial pH of 4.5. Under the optimum condition, the treatment increased to 80% COD removal with simultaneous increase of biopolymer by about 2 folds (52.2 mg/g biomass). Therefore, bioaugmentation of R. oryzae ST 29 in POME not only enhanced the treatment efficiency but also generated biomass, enzymes, and biopolymer (MW 17,700 Daltons) as bioproducts.

This study uses stable isotope ratios to investigate the influences of terrestrial inputs of organic matter on the water properties and bottom sediments of coastal seas. The carbon stable isotope ratio (δ¹³C) of particulate organic carbon (POC) and the C/N ratio of particulate organic matter (POM) were obtained following a flood event in 2004, and under normal weather conditions in 2005, from the Seto Inland Sea, Japan. The δ¹³C of the bottom sediments was also measured in 2005. Under normal weather conditions, POM was derived mainly from phytoplankton, which sank to the seabed and became incorporated into the bottom sediments. During the flood event, terrestrial POC spread over 60 km from the source, and the extent of the influence was much larger than that seen in other coastal seas in Japan. The salinity distributions, as well as the concentration and stable isotope ratio of POM, indicated that residual currents such as estuarine circulation may play an important role in spreading terrestrial POC. The longitudinal gradient of δ¹³C-POC in the sediments indicated that the terrestrial POC also impacted on the composition of the seabed deposits.

Water sampling was conducted in the coastal area of Tokyo following two rainfall events in October and November 2016. The coastal area receives, through urban rivers, a considerable amount of combined sewer overflow (CSO) pollutants from overflow chambers and pumping stations. Five pharmaceutical and personal care products (PPCPs) including acetaminophen, theophylline, crotamiton, carbamazepine, and caffeine were analyzed and used as chemical sewage markers. In addition, two types of bacteriophage were counted as markers for viral contamination as well as the fecal bacterial indicators Escherichia coli and total coliform. High contamination by PPCPs and microbial fecal indicators was observed after the rainfall events. Five key markers were selected among nine target markers using correlation analysis and were used to express the spatial distribution and temporal change in CSO pollutants. Escherichia coli showed relatively fast die-off behavior and decreased sharply from one day after the rainfall events, while bacteriophages persisted for several days after the events. Somatic coliphage showed more persistent behavior than F-specific bacteriophage. Labile markers such as caffeine also showed high rates of disappearance. In addition, monitoring results suggested that combined analyses of PPCPs and microbial fecal indicators can provide a more informed discussion on the distribution and diffusion of sewage contaminants in coastal waters following rainfall events.