Extraction of raw sewage sludge containing iron phosphate for phosphorus recovery

The objective of the present study was to establish an alkali extraction technology for FePO₄-containing sewage sludge obtained from a wastewater treatment system that includes phosphorous removal by iron electrolysis. By clarifying the extraction properties of phosphorous, organic matter, and inorganic matter, conditions for alkali extraction were optimized. As a result, it was suggested that unheated phosphorous extraction would be superior for FePO₄-containing sewage sludge. And, extraction methods and sewage sludge properties were also compared, and the noteworthy result that extraction of metals can be suppressed to extremely low amounts with alkali extraction as compared with acid extraction was obtained. A new insight was also gained that, as compared with the use of incinerated ash reported in previous studies, alkali extraction was more efficient when raw sewage sludge was used.     

A GAME-THEORETIC APPROACH TO ACID RAIN ABATEMENT: CONFLICT ANALYSIS OF ENVIRONMENTAL LOAD ALLOCATION1

ABSTRACT: The detrimental impacts of acid rain have become widely publicized, but effective and equitable methods to mitigate the acid rain problem remain to be found. This paper focuses on conflicts involved in allocation of the total emission loads to be reduced to respective pollution sources of acid rain, and proposes a game-theory approach to the resolution of the conflict. With an example abstracted from a hypothetical case study in the United States of America and Canada, a systematic analysis is performed and policy implications of the results examined to assess the applicability of the proposed model.     

土壤渗滤法对典型污染河段河水的净化效果

土壤渗滤法是一种就地污水生态处理技术,它充分利用土壤中的动物、微生物、植物以及土壤的物理、化学特性,能高效去除COD、BOD5以及氮、磷等营养物质,对水源保护和分散型污废水治理的意义重大.就上海虹桥机场围场河典型污染河段进行土壤渗滤法水质生态修复试验,结果表明COD的去除率高达75.8%,TP的去除率高达100%,水体中的溶解氧显著提高,各种有机物也得到相应的降解.同时,结合土壤渗滤法的主要特点及应用前景,对围场河水质生态修复提出了综合性的建议.     

Variation in CO2 assimilation rate induced by simulated dew waters with different sources of hydroxyl radical (*OH) on the needle surfaces of Japanese red pine (Pinus densifora Sieb. et Zucc.)

The hydroxyl radical (*OH) is generated in polluted dew on the needle surfaces of Japanese red pine (Pinus densiflora Sieb. et Zucc.). This free radical, which is a potent oxidant, is assumed to be a cause of ecophysiological disorders of declining trees on the urban-facing side of Mt. Gokurakuji, western Japan. Mists of *OH-generating N(III) (HNO2 and NO2-) and HOOH + Fe + oxalate solutions (50 and 100 microM, pH 5.1-5.4) simulating the dew water were applied to the foliage of pine seedlings grown in open-top chambers in the early morning. Needles treated with 100 microM N(III) tended to have a greater maximum CO2 assimilation rate (Amax), a greater stomatal conductance (g(s)) and a greater needle nitrogen content (Nneedle), suggesting that N(III) mist acts as a fertilizer rather than as a phytotoxin. On the other hand, needles treated with 100 microM HOOH + Fe + oxalate solution showed the smallest Amax, g(s), and Nneedle, suggesting that the combination of HOOH + Fe + oxalate caused a decrease in needle productivity. The effects of HOOH + Fe + oxalate mist on pine needles were very similar to the symptoms of declining trees at Mt. Gokurakuji.     

Styrene dimers and trimers affect reproduction of daphnid (Ceriodaphnia dubia)

The endocrine disruptor activity of styrene in humans and other vertebrates appears to be negligible. However, offspring numbers were reduced in Ceriodaphnia dubia bred in polystyrene cups. Styrene dimers and trimers were found to be eluted from the polystyrene cups by hexane and methanol with gas chromatography-mass spectrometry. Styrene dimers and trimers at concentrations of 0.04-1.7 microg/l affected C. dubia fertility (25% reduction after seven days), suggesting that styrenes have the potential to impair crustacean populations in the aquatic environment.     

Investigation of flow structure with moat acting as a water cushion at the toe of an overflowing levee

Environmental Fluid Mechanics - The principle theme of this study is to introduce a novel countermeasure to reduce the energy of the overflowing floodwater by utilization of a water cushion. For...     

Sexually differentiated functions of female-produced pheromone of the black chafer <Emphasis Type="Italic">Holotrichia loochooana loochooana</Emphasis> (Sawada) (Coleoptera: Scarabaeidae)

Summary. Both male and female Holotrichia loochooana loochooana (Sawada) (Coleoptera: Scarabaeidae) were attracted with female-produced pheromone, anthranilic acid (2-aminobenzoic acid), in the field. Male chafers were observed to apparently directly locate cotton balls impregnated with 1 to 10 mg of pheromone. In contrast, females never directly oriented to the treated balls but landed 0.2-1.5 m away and exposed their abdominal glands in a calling posture, which occasionally resulted in aggregation of both females and males. This suggested the mating aggregation of this species could be primarily induced by pheromone released by females. A hypothesis for adaptability of female aggregation is proposed and discussed.     

Geosmin degradation by seasonal biofilm from a biological treatment facility

Introduction  

Initial geosmin degradation was closely related to water temperature and natural geosmin concentration of sampling environment. Here, for the first time, we evaluated the biodegradation of geosmin by microorganisms in biofilm from biological treatment unit of actual potable water treatment plant.     

Experimental study on flow analysis and energy loss around discontinued vertically layered vegetation

Environmental Fluid Mechanics - Vegetation acts as a natural protection measure as it reduces inundation depth downstream of it and dissipates the energy of flow like flood and tsunami. The present...