Field survey of a sustainable sanitation system in a residential house

Sustainable sanitation is an approach for more ecological and sustainable water resources management. In this paper, we proposed one of the new integrated waste treatment systems： an ＂sustainable sanitation system＂ that includes separation of the black water from water system by a non-flushing toilet （bio-toilet）, and a gray water treatment based on a biological and ecological concept. Sustainable sanitation system also converts the domestic waste to soil conditioners and fertilizers, for farmland use. As one of the case studies, Environmentally Symbiotic Housing in which people actually live using the bio-toilet for the black water treatment and the household wastewater treatment facility for the gray water was introduced. The availability of this system was investigated by analyzing the sawdust used in the bio-toilet and the quality of the effluent in the household wastewater treatment facility. As the result, the water content of the sawdust did not exceed 60% in any of the sampling points and the BOD and COD of the effluent of the household wastewater treatment facility were below 10 and 20 mg/L respectively, due to the low loading. Compared to the pollution load on the water environment created by the conventional system, it was found that the effluent of the house has a lower load than the tertiary treatment and the volume of the water consumption is 75% of the conventional system.     

Anaerobic co-digestion of dairy cow manure and high concentrated food processing waste

Anaerobic co-digestion of dairy manure (DM) and concentrated food processing wastes (FPW) under thermophilic (55 °C) and mesophilic (35 °C) temperatures, and fertilizer value of the effluent were investigated in this study. Two types of influent feedstock were utilized: 100 % DM and a 7:3 mixture (wet weight basis) of DM and FPW. The contents of the FPW, as feedstock were 3:3:3:1 mixture of cheese whey, animal blood, used cooking oil and residue of fried potato. Four continuous digestion experiments were carried out in 10 L digesters. Co-digestion under thermophilic temperature increased methane production per digester volume. However, co-digestion at 35 °C was inhibited. Total Kjeldahl nitrogen (N) recovered after digestion ranged from 73.1 to 91.9 %, while recoveries of ammonium nitrogen (NH₄-N) exceeded 100 %. The high recovery of NH₄-N was attributed to mineralization of influent organic N. The mixture of DM and FPW showed greater recoveries of NH₄-N after digestion compared to DM only, reflecting its greater organic N degradability. The ratios of extractable to total calcium, phosphorus and magnesium were slightly reduced after digestion. These results indicate that co-digestion of DM and FPW under thermophilic temperature enhances methane production and offers additional benefit of organic fertilizer creation.     

Effect of the carbon coating in Fe-C-TiO(2) photocatalyst on phenol decomposition under UV irradiation via photo-Fenton process

Fe-C-TiO(2) photocatalysts which contained the residue carbon (0.2-3.3 mass%) were prepared from a mixture of TiO(2) and FeC(2)O(4) through the heating at 673-1173 K in Ar. These photocatalysts did not show a high adsorption of phenol, but they were active in photo-Fenton reactions during decomposition of phenol under UV irradiation with addition of H(2)O(2). It was proved that Fe(2+) governed the photoactivity of Fe-C-TiO(2) photocatalysts, it decreased with heat-treatment temperature above 773 K. For comparison, Fe-TiO(2) photocatalyst was prepared by heating TiO(2) and FeC(2)O(4) at 823 K in air for 3h. Phenol decomposition was going much slower on Fe-TiO(2) photocatalyst in comparison with Fe-C-TiO(2), of which mechanism was different, on the former phenol was decomposed by the radical reaction, on the latter through a complex reaction with iron and intermediates of phenol decomposition. Therefore carbon-coating TiO(2) was found to be advantageous for mounting iron and its application for the phenol decomposition via photo-Fenton process.     

Predicted distribution of 16 short-chain chlorinated paraffins in air,water, soils and sediments

Environmental Chemistry Letters - Short-chain chlorinated paraffins are industrial contaminants of great concern due to their persistent and toxic characteristics. The predicted distribution of...     

Enantioselective recognition of mono-demethylated methoxychlor metabolites by the estrogen receptor

Metabolites of methoxychlor such as 2-(p-hydroxyphenyl)-2-(p-methoxyphenyl)-1,1,1-trichloroethane (mono-OH-MXC) and 2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane (bis-OH-MXC), have estrogenic activity. Mono-OH-MXC is a chiral compound in which the carbon atom bridging two benzene rings is the chiral centre. In previous studies the estrogenic activity of racemic mono-OH-MXC has been measured, and the activity of each enantiomer of this compound has not yet been elucidated. In this study, we evaluated the estrogen receptor-binding activity of each enantiomer of mono-OH-MXC to clarify the enantioselective recognition by the estrogen receptor. (S)-mono-OH-MXC showed 3-fold higher binding activity than that of the (R) enantiomer. The activity of bis-OH-MXC was only 1.7-fold higher than that of (S)-mono-OH-MXC. This result suggests that the one hydroxy group and the orientation of the CCl3 group of mono- and bis-OH-MXCs are important for the interaction with the estrogen receptor. The result also points out the estrogenic activity of methoxychlor after metabolic activation in vivo, which predominantly produces the (S)-mono-OH-MXC, may be higher than estimated from the in vitro activity of racemic mixtures.     

A pilot and field investigation on mobility of PCDDs/PCDFs in landfill site with municipal solid waste incineration residue

A field investigation by boring was carried out in a landfill site primarily with municipal solid waste incineration residue. From the collected core samples, vertical profiles of homologous content of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs) in the landfill layer were traced and the behavior of PCDDs/PCDFs was examined. In addition, a pilot-scale study was conducted on the PCDDs/PCDFs leached from incineration fly ash and the treated one using large landfill simulation columns (lysimeters) and the leaching behavior of PCDDs/PCDFs was examined. As a result, it was found that the coexistence of dissolved coloring constituents (DCCs), which might be composed of constituents like dissolved humic matters having strong affinity for hydrophobic organic pollutants, could enhance the leachability of PCDDs/PCDFs, thus contributing to the vertical movement and leaching behavior of PCDDs/PCDFs in the landfill layers of the incineration residue. Moreover, it is highly probable that DCCs derive from the unburned carbon in the bottom ash mixed and buried with the fly ash containing a high content of PCDDs/PCDFs.     

A study on forecasting paths of genuine savings and wealth without and with carbon dioxide constraints: development of shadow price functions

This paper has developed a method for forecasting the future paths of genuine savings (GS) with and without carbon dioxide (CO₂) emissions constraints. GS calculations require shadow prices, which can be endogenously determined for variables and constraints in a model. However, in case of a ‘business as usual’ model (BAU), the shadow prices required for calculating GS without constraints show theoretically zero. This research derives the shadow prices required to measure GS for the BAU case as a function of several variables available in the optimal (economically efficient) case. This function is estimated from endogenously obtained variables from a model with environmental constraints. Subsequently, this function is used to calculate shadow prices with and without CO₂ constraints, which are further employed to compute future paths of GS according to two methods applied in the papers by Arrow et al. We successfully estimated GS (or GSnt; GS with changes in population and technology) under the BAU case, however, suggest that GS (or GSnt) measures depend, to a great extent, on the time span under consideration (truncation year) for wealth accounting and the accounting methods by Arrows’ papers used for its estimation. In some cases, especially according to the methodology used by Arrow’s paper in 2004 using adjusted consumption in wealth accounting, the sign of GS (or GSnt) changes from negative to positive when changes in total factor productivity are taken into consideration. These aspects should be explored before measuring (un)sustainability of a particular path based on the GS (or GSnt) indicator.     

Genetic structure and gene flow of eelgrass <Emphasis Type="Italic">Zostera marina</Emphasis> populations in Tokyo Bay,Japan: implications for their restoration

Massive losses of eelgrass Zostera marina beds in Japan have occurred over the past 100 years. Toward their restoration, transplantation of eelgrass has been attempted in some areas, including Tokyo Bay. This study examined population genetic structures and gene flow in eelgrass in Tokyo Bay to establish guidelines for conducting restoration. Genotypes of a total of 360 individuals from 12 beds were determined using five microsatellite markers. The eelgrass beds in inner bay had above-average genetic diversity. A neighbor-joining tree based on F _ST values among beds revealed that a strong gene flow had occurred among six beds in the inner bay. Genetic assignment testing of drifting shoots indicated that those with seeds migrate in both directions between the inner and outer bay. We suggested that the restoration of eelgrass in the innermost part of Tokyo Bay, where natural habitats have been lost, should be conducted using the inner bay beds.     

The seasonal effects of manure management and feeding strategies on hydrogen sulphide emissions from stored dairy manure

Journal of Material Cycles and Waste Management - The influence of temperature and storage time on hydrogen sulphide (H2S) emissions from two different dairy manures was investigated over four...     

Hydrolysis of <Emphasis Type="Italic">Sasa senanensis</Emphasis> culm with dilute sulfuric acid for production of a fermentable substrate

To prepare a substrate for microbial conversion of xylose into xylitol, the culm of Sasa senanensis was hydrolyzed with dilute sulfuric acid. When the reaction temperature was fixed at 121°C, an optimum yield of xylose was obtained by treatment with 2% sulfuric acid for 1 h. An increase in the sulfuric acid concentration or a prolonged reaction time resulted in a decrease in the xylose yield. A fermentable substrate with a relatively high xylose concentration (36.7 g l⁻¹) was obtained by hydrolysis with 2% sulfuric acid with a liquid-to-solid ratio of 5 g g⁻¹. During hydrolysis at elevated temperatures, certain undesired byproducts were also generated, such as degradation products of solubilized sugars and lignin, which are potential inhibitors of microbial metabolism. These compounds were, however, successfully removed from the hydrolysate by treatment with activated char.