Some kind of high concentration wastewater has great potencial for treatment and recovery of energy by means of anaerobic digestion.
A study on thermophilic anaerobic digestion using methanol synthetic wastewater was performed with a membrane separation process. The operation tests were investigated using a fixed-bed reactor packed with porous pumice stone and ultra-filtration (UF) membrane module for microbial retention.
The results of continuous experiments revealed that : 1) the nutrients require were BOD : N : P=100 : 0.7 : 0.1, 2) the hydraulic retention time was 0.56 day 3) the maximum BOD volmetric loading rate was 69.5 g-BOD·l^-1·d^-1, 4) the average BOD removal rate was 99.5%, and 5) the circulated VSS in the bioreactor with a UF membrane was highly concentrated and had a high efficiency of methanol consumption and gas production.

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Effect of phosphorus on water treatment with biological activated carbon (BAC) was studied by evaluating the biodegradation rates of glucose and humic acid with BAC-attached bacteria, the ability of BAC-packed column to remove these organic matters, and the change in the number of bacteria in the water in the presence and absence of phosphorus. Addition of phosphorus to the sample water increased the number of bacteria in BAC and resulted in an improvement of the ability of BAC-packed column to remove glucose. High molecular weight organic phosphorus, DNA, as well as inorganic phosphate, was available as phosphorus source for the bacteria in BAC. The ability of the BAC-packed column to remove humic acid was not improved with phosphorus, because humic acid with high molecular weight was so hard to be utilized as a sole carbon source that the BAC-attached bacteria could not grow. However, humic acid was found to be degraded slowly to lower molecular weight matter depending on the number of bacteria in the BAC-packed column. These results indicated that phosphorus content in sample water was an important factor to control the ability of BAC to remove organic matters.

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Four concentration methods ; XAD resin adsorption, CSP/CHPA resin adsorption, dichloromethane solvent extraction, and blue rayon adsorption were compared for their abilities to concentrate mutagens from leachate samples obtained from a municipal solid waste landfill. The Ames Salmonella/microsome assay was used to evaluate the four methods. The XAD resin adsorption, the CSP/CHPA resin adsorption, and the solvent extraction well recovered mutagens from leachate samples, while the blue rayon adsorption could scarcely recover mutagens, suggesting that polyaromatic hydrocarbons having 3 or more fused aromatic rings in their structures less contribute to the mutagenic activity of landfill leachate. Mutagens were well recovered only after leachate samples were acidified. Therefore, it is likely that predominant mutagens in landfill leachate are acidic compounds. TA98 detected mutagenicity of concentrates better than TA100 and the addition of S9 did not increase the number of revertants.
Judging from these results, the XAD resin adsorption, the CSP/CHPA resin adsorption, and the solvent extraction are suitable for concentrating mutagens from landfill leachate.

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Reactivity or degradation of 135 pesticides was investigated in waters containing residual chlorine and ozone to clarify their behaviors in water purification processes, and discussed with respect to their molecular structures (or functional groups).
The pesticides were divided into two groups according to their reaction behaviors to chlorine and ozone. One group was for pesticides reactive with chlorine and more reactive with ozone, and another included pesticides undegradable by chlorine but easily degradable by ozone. Function groups or chemical structures reactive with both chlorine and ozone were thiophosphoryl, sulfide, dithiocarbamate, thiocarbamate, uracil and phenol. Ether bond such as aliphatic hydrocarbon (Al)-O-Al and aromatic hydrocarbon (Ar)-O-Al and Cl-unsubstituted C=C (double) bond were degraded not by chlorine but by ozone. Ar-O-Ar ether, ClC=C (double) bond, phosphoryl groups, dinitroaniline and dinitrophenol were undegradable by both chlorine and ozone.
With respect to molecular structure, triazine, acid-amide, carbamate and diphenylether were basically stable against both chlorine and ozone. Reactivity of pesticides including any these structure seemed to be derived from inner side-chain(s) with reactive site(s) for chlorine or ozone.
The results showed that there were much more pesticides reactive with ozone than those with chlorine.

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