To obtain information that can be used as reference for improving the environment inside and surrounding the open channels receiving johkasou effluent, the formation and correlation of sediment bed bacterial density with water quality were evaluated with multivariate statistical analysis based on measured data for water and sediment samples collected for 8 times from 6 sites of an open channel that receives johkasou effluent in a residential area of Gifu Prefecture, Japan. Statistical analysis included principal component and factor analysis (PCA/FA), cluster analysis (CA) and correlation analysis. The PCA/FA results showed that 3 dominant factors were responsible for the water quality data structure, accounting for 85.12% of the total variance in the dataset. Hierarchical cluster analysis grouped 6 study sites into 3 statistically significant clusters, reflecting different characteristics and pollution levels of the sites. Correlation analysis revealed statistically significant relationships of the sediment bed bacterial density with BOD, total nitrogen and total phosphorus in the water of the channel receiving johkasou effluent.

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The polymerization process with a simple step has become the centre of attention of several researchers. Various polymers have been developed, although in general, they use polymerization with a post-modification method. A quaternary ammonium monolith organic polymer has been prepared using a simple single thermal method in this research. 2-(Methacryloyloxy)-N,N,N-trimethylethanaminium chloride was as the monomer, and ethylene dimethacrylate was as crosslinker. The polymerization proceeded in fused-silica capillary (100 mm, 0.32 mm i.d. x 0.45 mm o.d.) using a one-pot approach method. To achieve the perfect macropores, isopropyl alcohol, PEG 400, and ethanol were used as porogen. Characterization of the surface morphology was carried out using a Scanning Electron Microscope (SEM), and the existence of an amine group was characterized by Fourier Transform Infrared Spectroscopy (FTIR). The distribution size of pores in the polymer was in the range of 1.29 to 3.33 µm.Abstrak: Polimerisasi dengan proses yang sederhana dan simpel menjadi pusat perhatian beberapa peneliti. Berbagai macam polimer telah dikembangkan, akan tetapi pada umumnya menggunakan polimerisasi dengan metode post-modification. Pada penelitian ini, polimer organik yang mengandung amonium kuartener dalam bentuk monolit dengan polimerisasi yang menggunakan suhu tunggal dan sederhana telah dilakukan. 2-(Methacryloyloxy)-N,N,N-trimethylethanaminium chloride digunakan sebagai monomer dan ethylene dimethacrylate sebagai crosslinker. Polimerisasi dilakukan dengan metode one-pot aaproach di dalam kapiler silika (100 mm, 0,32 mm i.d. x 0,45 mm o.d.). Untuk mendapatkan makropori yang sempurna, isopropil alkohol, PEG 400 dan etanol digunakan sebagai porogen. Karakterisasi morfologi permukaan dilakukan dengan menggunakan Scanning Electron Microscope (SEM), dan Fourier Transform Infrared Spectroscopy (FTIR) untuk mengidentifikasi gugus fungsi gugus amina yang terdapat pada polimer. Ukuran distribusi pori pada polimer berkisar antara 1,29 sampai 3,33 µm.

A johkasou system is getting popular as a decentralized wastewater treatment system in low-density communities. Treated waters of the johkasou systems, which are generally discharged into channels within residential areas before entering the local receiving water body, may contain microbial contaminants. To identify the characteristics of fecal indicators in the channels of the johkasou systems, the concentrations of fecal indicators (F-RNA bacteriophages, GIII F-RNA bacteriophages, Escherichia coli, and total coliforms) were examined both in water and sediment in the channels of three johkasou systems. These fecal indicators were always detected at high levels both in water and sediment in the channels of three johkasou systems through the study period. Significant differences in concentrations of fecal indicators were not observed among three johkasou systems in different residential areas. Concentrations of fecal indicators fluctuated in a day mainly due to domestic activities. Significant positive correlations of total coliforms and E. coli in water with total coliforms and E. coli in sediment suggest the potential importance of sediment on microbial dynamics in the channels of the johkasou systems. No significant correlations of F-RNA bacteriophages with total coliforms and E. coli indicate a specific distribution mechanism for F-RNA bacteriophages.

Abstract. Onsite application of oxygen supply in domestic wastewater system may be influenced by several factors that can inhibit the oxidation and nitrification processes. In this study, the influence of aeration rate on the Johkasou performance was focused using two Johkasou facilities serving up to five persons household. In the Johkasou A (JO-A) system, we increased the aeration rate from 30 to 63 L.min -1 whereas, in the Johkasou B (JO-B), it was decreased from 59 to 34 L.min -1 . Water and sludge samples were collected from the anaerobic-anoxic-oxic zones before and after adjustment of the aeration rate measured for organic matters and nitrogen parameters. Increasing the aeration rate in JO-A resulted in a high removal of organic matter (82.5%) and nitrogen (60.3%) compared to decreasing of aeration rate in JO-B (52.0% and 33.0%, respectively). Simultaneous nitrification and denitrification (SND) exhibited a maximum percentage when the aeration rate was increased compared to decreasing of aeration rate. These results indicate that application of a high aeration rate increases removal of organic matter and nitrogen and enhances ammonia transformation. It is therefore recommended to apply high aeration rates in Johkasou system.