Organic substances and heavy metals in the incinerated residues and in the leachate were investigated. The reasonable ignition loss of the incinerated residue (600°C, 3hr) except uncombustibles for the operation of the incineration plants was about 5%.

View full abstract

Waste water produced by cooling process of the hot ash from the furnace at the waste water treatment Plant of a municipal refuse was analized, and conditions for hydrogen sulfide formation was investigated. The waste water contained organic carbon and sulfur compounds of high concentrations, and the values of D. C., pH and O. R. P. (oxidation reduction potential) at the treatment tanks except the flight conveyer satisfied the requirement for sulfate bacterial reduction. These facts indicate that the waste water is very liable to liberate hydrogen sulfide of high concentrations. In cultivating experiments of the filtrate of the waste water at the flight conveyer the value of O. R. P. increased at first and then decreased, and when it approched - 200 mV, the value of sulfide ion electrode potential began to decrease, indicating the begining of the sulfate reduction. The GC analysis of lower fatty acids in a cultured solution indicated that along with development of anaerobic digestion, the concentrations of acetic, propionic and n-butyric acids increased and the increasing ratio of propionic acid was the largest among them. The later characteristic was also observed in the waste water in the treatment plant.

View full abstract

Adsorption amounts of arsenite (AsO^3-₃) and arsenate (AsO^3-₄) on eleven samples of soils were determined, and the correlations between the amounts and organic matter, cation exchange capacity (CEC), free Al included in the soils and the immersion period (1-7 days) were investigated.
The results showed that the adsorption amounts of AsO^3-₄ on soils were far great than that of AsO^3-₃ in 1 day immersion period, however the adsorption amounts of AsO^3-₃ markedly increased during the immersion period from 1 to 7 days.
No significant correlation was found between the amounts of adsorbed As and organic carbon or CEC. However, the amounts of adsorbed As, especially adsorbed AsO^3-₄ in 1 day immersion, were positively correlated with free Al resulting from allophane which were extracted with Nacitrate and K-oxalate.
As adsorption isotherm for Zenigamezawa second horizon soil and for charcoal were determined by immersing the sample in AsO^3-₃ and AsO^3-₄ solutions of 0.5-50mg As/l at 30t.
The results showed that adsorption of As obeys the Freundlich isotherm equation, however, adsorpti on of AsO^3-₃ on the soils and AsO^3-₄ on charcoal at 7 days immersion did not obey the equation at the concentration less than 0.4 ppb As.

View full abstract