Air pollutant emissions from incinerations of sewage sludge and municipal refuse are discussed. They are particulated matter, nitrogen oxidase, sulfur oxides, hydrogen chloride, carbon monoxide, hydrocarbons, ammonia, hydrogen cyanide, heavy metals, etc. Emission mechanisms and emission control measure of these substances also are referred to. Detailed explanation is concentrated on the flue gas treatment systems for particulated matter and hydrogen chloride, and in-the-furnace denitrification method developed by the authors.

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Trajectory analysis and divergence analysis are made for the ground level wind data covering Kanto district under the condition of the weak atmospheric pressure gradient in summer season.
It was found that weak wind zone is observed near the western mountain area. In this area wind stagnation and convergence are formed and continue for a long time.

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Principal Component Analysis (PCA) was made for the ground level wind data covering Kanto district under the condition of the weak atmospheric pressure gradient in summer season.
Analyses show that the first principal component denotes wind direction and strength, the second component denotes the circulation of wind, and the third component denotes wind stagnation.
Kanto district divided into some groups using the score value of these principal components.

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A gas collector using membrane filter for simple measurement of pollutant gases in ambient air has been designed and constracted. The membrane filter has special feature of preventing permeastion of absorbent solution but permitting diffusion of gas freely.
In the present investigation, deter mination of NO₂ and NH₃ in ambient air were studied. The collecting coeffient of NO₂ and NH₃ were widely diffrent by the chemical properties between gases and absorbent solution. The absorbing reaction of NO₂ and Saltzman's solution and sodium carbonate solution is comples that two more ion speacis arises in the absorbent solution and only a part of NO₂^- was determined after the color development reaction. Scince, the collection factor of NO₂ was largely affected by concentration and temperature, but not affected by humidity. Then in the limited range less than 0.08 ppm, NO₂ can be determined using the factor calibrated by standard gas.
The absorption mechanism of NH₃ and boric acid solution is simple as acid-base nutralization, Using 0.5% boric acid solution, the concentration of NH₃ is obtained by following experimental equation.
C=0.62×υ/A·T×(273/273+t)^1.75
Where C is the concentration NH3 (ppm) in ambient air at t°C, a is the amount of absorbed NH₃ (μl), A is the effective area of membrane filter (cm₂), T is the exposure time (h) and t is the average temperature (°C).

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A simple and reliable semimicro-method for sulfur dioxide (SO₂) and sulfite ion (SO₃^2-) in small scale samples is developed on the basis of the standard pararosaniline method. The amount of the solution for colorimetry is minimized to one twenty-fifth (1.0ml) by using a microcell (2×10 mm; volume, 0.5 ml). In addition, precisely calibrated ad justable pippettes with pushbutton operation and 2. 5 ml small stoppered test tubes are used for small size solutions and for simplification of the coloring. The precision of this method was about 1% in coefficient of variation; slightly lower than that of the standard method, but it is high enough for general purposes.
The micro-bubbler was devised to transfer SO₂ in gas samples in containers to 0.68 ml absorbing solution (0.04 M potassium tetrachloromercurate, TCM) and the microsyringe (10 or 100 μl) sampling technique was studied out for small size liquid samples. The semimicro-method with these techniques was applied to the analysis of SO₂ of 1 ppm or above in 100 ml gas samples taken in a 200 ml syringe, a gas sampling tube and a Mylar bag and of SO₃^2- of 2μg/ml or above in 10μl rain drops.

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Dissolution of nitrogen oxides (NO and NO₂) into water was studied with regard to the intake process of NO_x by living body. NO_x mixed with N₂ was passed in bubblers at 25°C. NO₂^- and NO₂^-+NO₃^- were analyzed with colorimetric methods. NO dissolves physically in the absence of O₂ and obeys Henry's law. NO₂ (20-80 ppm (v/v)) dissolves and gives rise to equal amounts of NO₂^- and NO₃^- regardless of the existence of O₂. The rate of NO₂ dissolution is proportional to the gaseous concentration of NO₂. The dissolution of NO+NO₂ (NO: 230-630 ppm (v/v)), NO₂: (25-70 ppm (v/v)) produces NO₂^- exclusively in the absence of O₂. The rate depends linearly upon the gaseous concentration of NO₂ irrespective of the concentration of NO. The rate constant of the dissolution of NO+NO₂ approximately equals that of NO₂, which suggests that both reactions proceed with the identical rate determining step. The dissolution of NO in the existence of O₂ (NO: 100-470 ppm (v/v), O₂: 50%) likely proceeds with the gaseous oxidation of NO and the subsequent dissolution of NO+NO₂. The rate constant k of the oxidation of NO with O₂ was calculated according to the above mechanism. The value of k thus obtained agreed well with that reported by Stedman and Niki.

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The Navier-Stokes' equation of forward difference schemes with nonlinear terms and variable coefficients was solved numerically, using Runge-Kutta-Gill's method. A simulation was carried out with the model over a flat surface where thermal condition was uniform horizontally and sulface roughness increased abruptly along wind direction.
The result showed upward wind component in accordance with deceleration of horizontal air current and increased diffusivity in the developing internal boundary layer in just leeward area above the surface roughness gap. The ceiling of internal boundary layear reached to a fixed height which had relations with stability and a new stationary wind profile was reformed in the adapted layer in the leeward in internal boundary layer. If a height normalized with ceiling of the internal boundary layer was introduced, peak of diffusion coefficient was found almost in the same height in any stability category, which suggested that adapted wind profiles satisfied a similarity law.
Supposing an emission of air pollutant at a windward point above the roughness gap, transfer and diffusion were estimated in the internal boundary layer. The result revealed that air pollutant floated over the internal layer in unstable condition and invaded in a long tongue shape into the internal boundary layer in stable condition.
A numerical model of internal boundary layer produced by the irrgular thermal condition of the ground surface will further be required as the next task.

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Atmospheric dibutyl phthalate (DBP) and diethylhexyl phthalate (DEHP) were sampled on a glass fiber filter and two polyurethane foam plugs in series by darwing 35 m³ of an air sample at (11-14) lmin for 48h and determined by a gas chromatograph with an electron capture detector via an extraction technique. The blank values of DBP and DEHP corresponding to 35m³ of air were (3-10) ng/m³ and (1-5) ng/m³, respectively, and were less than one-eighth and one-tenth of the concentrations of DBP and DEHP, respectively, in the ambient air. The relative standard deviation of determined values of DBP in the ambient air was 4. 98% and that of DEHP was 6.48%. In the sampling, DBP tended to pass through the glass fiber filter, and DEHP tended to be trapped in great deal on the filter. The result shows that DBP is abundant in gas phase and DEHP is abundant in particulate phase. Concentrations of atmospheric DBP and DEHP were determined from October 1977 through October 1978 at Environmental Pollution Control Center. The yearly average concentrations of atmospheric DBP and DEHP were 192 ng/m³ and 99. 1 ng/m³, respe ctively. The concentrations of DBP (C_DBP) were highest in the summer and lowest in the winter. The concentrations of DEHP (C_DEHP) were higher in the summer than in the winter. The (C_DBP)/(C_DEHP) and (C_DBP)/concentrations of airborne particulate matter (C_PM) exponentially increased as ambient temperature increased. The yearly average of the (C_DBP)/(C_DEHP) value was 1. 76, and was much higher than the ratio of DBP to DEHP industrially produced in Japan. The correlation coefficient between (C_OBP) and (C_PM) was -0.012. These results suggest that the ambient contamination by DBP is mainly caused by vaporization of DBP from products containing DBP. The (C_DEHP)/(C_PM) value tended to be higher as ambient temperature increased. The correlation coefficient between (C_DEHP) to (C_PM) was 0.721. From these results the ambient contamination of DEHP seemed to be caused by emission from industrial factories, by cutting or abrasion of products containing DEHP and by vaporization of DEHP from products containing DEHP.

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In order to reutilize waste liquor spent for deodorization, decomposition of sodium hypochlorite remaining in it was tried using columns packed with activated carbon (coal-base).
The optimum condition was found to be as follows; temperature: a room temperature, pH of the liquor: around 10, flow rate of the liquor: 6m/h. Under this condition, 400-800 ppm (w/w) of sodium hypochlorite was decomposed almost completely at the decomposing rate of ca. 0.5g NaOCl/g carbon.

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