This paper describes a highly efficient chemical/biological treatment process for photo-processing waste (PW) . This process has“demonstrated”treatment efficiencies of 96% for total organic carbon (TOC) and chemical oxygen demand (COD), 99% for total nitrogen (T-N), and 98% for total phosphate (T-P) . The process involves the initial treatment of raw PW by peroxide oxidation, followed by dilution (3 to 6 times) and an aerobic biological activated carbon (BAC) treatment. The waste stream is then subjected to biological denitrification using an up-flow anaerobic sludge blanket (UASB) system.
By taking advantage of Fe²⁺, S₂O₃^2-, and SO₃^2- contained in PW, the Fenton reaction was touna to act instantly upon peroxide oxidation without adding Fe²⁺ or adjusting pH levels. Results showed that the oxidation process sharply decreased TOC and COD to 40% and 20%, respectively, while simultaneously improving the biodegradation of refractory compounds. Moreover, by neutralizing the peroxide oxidation solution, 98% of the waste's T-P was removed. In the aerobic BAC system, where the load of ammonium nitrogen and the hydraulic retention time (HRT) were fixed respectively to 0.09 -1.0 kg-N/m³/d and 11.6- 3.7 d, the ammonium nitrogen was nitrified and organic compounds underwent degradation. As a result, the ammonium nitrogen was completely nitrified to nitrate or nitrite, and then denitrified to nitrogen via a biological denitrification process in which the denitrification rate was 99% (operating at the load of 0.39-0.78 kg-N/m³/d (HRT= 4.9-2.4 d) ) .

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To date, it has been financially difficult to control and suppress dioxins generated in all stages of the waste treatment and disposal, largely because the analysis cost of dioxins by GC/MS is more expensive. For this reason, as one easy, rapid and cost-effective screening method, the applicability of Enzyme Immuno Assay (EIA) for 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (2, 3, 7, 8-TCDD) was studied in this report. The sensitivity, reproducibility and concentration dependence in the dioxin EIA were investigated and confirmed. Standard-addition experiments to crude fly ash extract samples suggested something to influence upon EIA. Consequently, an EIA analysis at each stage of the clean-up process was investigated, and showed that there were no significant differences in data between the crude extracts and the refined samples. This indicated that crude extracts could be used for EIA. In the fly ash and stack gas sample EIA results, the data correlated to the TEQ value obtained by GC/MS analysis. However, there were some independent influences from dioxin amounts found in extracts of lower concentration samples. It was concluded that EIA would be a useful screening method for dioxins if rapid and easy extraction methods for removing abstructions were developed.

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The toxicity of municipal solid waste incinerator fly ash leachate, which was prepared via the standard Japanese leaching test, was evaluated by algal assay using Selenastrum capricornutum. The EC 50 was 1/1750 which showed that the toxicity of the leachate was high.
The concentration of heavy metals in the leachate and the EC 50 of each metal was compared in order to determine the major toxic element in the fly ash. The result showed that zinc was the major toxic element. This implied that zinc must be specifically targeted in MWI fly ash treatment and disposal.

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The concern regarding environment pollution by organic solvents such as trichloroethylene, and tetrachloroethylene has increased considerably. The current situation regarding the use and collection of solvents in laboratories at Osaka University were investigated according to the results of a questionnaire and a discussion on the ideal management for solvent handling was undertaken. It was found that there were noticeable differences in the solvent collection practices between laboratories. The reasons for a low collection rate were mainly related to the absence of a solvent management program in the laboratory and a lack of sence of solvent management on an individual level. The kind of solvents used in each laboratory also affected solvent collection. The discharge percentage of solvents into the air and sewage, estimated by combining the results of the interview survey, was more than 70% and less than 30%, respectively. Reflecting the history of the double violation on dichloromethane discharge regulation at the university, even though the sewage discharge percentage of the solvent was low overall (less than 15%), dichloromethane management should be considered much more seriously. The construction of a solid management system to handle the solvent is urgently required to prevent environmental disaster.

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Using the heat from waste incineration to generate electricity requires the addition of generating equipment, and the manufacture, construction, and operation of this equipment also uses energy. In this study, we examined the life cycle energy balance in relation to repowering, which is meant to increase MSW generating efficiency, as well as reburning, which is aimed at limiting both NOx and dioxin emissions. We found that these are effective methods for energy recovery, and that gas turbines combined with waste incinerators for repowering had the optimum size to improve overall efficiency.

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It is difficult to treat film-processing wastewater (FW) only with a single process, because FW contains many refractory chemicals such as EDTA and CD-4s. Fenton's reagents (FR) are known to produce a hydroxyl radical, which is one of the strongest oxidizing agents when ferrous iron is present as a catalyst. It is expected that a chemical and biological treatment process will be promising as a FW treatment. In this study we carried on the experimental degradation of 20 refractory photo-chemicals (metol, etc.) contained in FW to evaluate the effect of the first Fenton process on the biodegradability of chemicals in a second biological process. We also conducted the experimental degradation of the same chemicals using the reverse process, i, e., the biological process followed by the Fenton process. The Fenton oxidation tests showed that the chemicals were degraded by 30% to 50% in dissolved organic carbon (DOC) . The consequent biodegradation test (for 100 hours) resulted in a DOC removal rate of over 90%. On the other hand, the overall DOC removal was rated at about 60% for all chemicals except for EDTA when tested in the reverse processes. This suggested that the refractory chemicals must have been converted into biodegradable substances by FR.

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