In order to investigate the influence of secondary classification mode on waste generation features, this study classified domestic waste generated by 310 rural and urban households at urban areas and Shuigaozhuang Vi...In order to investigate the influence of secondary classification mode on waste generation features, this study classified domestic waste generated by 310 rural and urban households at urban areas and Shuigaozhuang Village of Xiqing District into 3 groups: compostable materials, recyclable materials and toxics on the basis of the constructed secondary classification mode of domestic waste. The study focused on waste generation strength and classification features, compared the waste generation features between rural and urban residents, and analyzed the re- lation between waste generation strength and economic and cultural factors. The re- sults indicated that the average generation speed of urban domestic waste was 423.08 g/(d.capita), and that of rural domestic waste was 629.89 g/(d.capita), there was significant difference between rural and urban compost generation strength (P= 0.00002), while the generation strength of recyclable materials and toxics between rural and urban areas had no significant difference (P=0.471 and P=0.099, respec- tively). Secondary classification mode is an effective source classification mode for domestic wastes and has positive effects on waste reduction and treatment.展开更多
On site composting of organic household wastes is an economical and environmentally tiiendly way to manage municipal wastes. In this manuscript authors evaluated the importance of turning the wastes and of inoculating...On site composting of organic household wastes is an economical and environmentally tiiendly way to manage municipal wastes. In this manuscript authors evaluated the importance of turning the wastes and of inoculating microorganisms and worms in order to unprove the composting process at domestic scale. Four treatments (Control without turning- C-, Control with Turning- CT- inoculated Mountain Microorganism with turning- MM- and Worms without turning- W-) were tested in a random experiment with tour replicates. Sixteen composting bins were fed with 300 kg of organic wastes from a local street market. The process of compostnig lasted 13 weeks after which all the composts were sifted and submitted to a range of chemical, physical and biological analysis. According to the results MM slightly increased the initial temperature and enzymatic activiry. This investigation outcome don't provide of sufficient grounds for a precise recommendation about worms inoculation in compost bins. A decrease between 75% and 80% in the fresh weight of the organic waste was found in the first thirteen weeks after starting the composting process in all the treatments. The quality level of the compost was acceptable, with very low heavy metal content. Turn over helps to keep the product hygienic especially after the inoculation with MM microbial starts. In conclusion and according to the results of this investigation, the use of 320 L compost bins for the organic waste management is strongly advisable.展开更多
The FAs (fulvic acids) belong to natural organic contaminants that are commonly found in different environments. In the process of oxidation and disinfection FAs are precursors of toxic substances, which cause a pro...The FAs (fulvic acids) belong to natural organic contaminants that are commonly found in different environments. In the process of oxidation and disinfection FAs are precursors of toxic substances, which cause a problem in many water treatment plants. In the sewage treatment plants, FAs are not biodegradable and together with purified wastewater and are discharged into surface waters. One of important source of the formation of FAs is the municipal landfill. In this thesis the authors test the amount of soluble fulvic acids present in the leachate of Barycz landfill in Krakow. The extracted FAs were subjected to a detailed analysis for the content of metals and IR spectrum analysis has also been done. Basing on elemental composition the C/O, C/H and C/N ratios have been determined. The obtained data were compared with the characteristics specified in the literature.展开更多
In order to clarify the influence of microbial agents on kitchen waste and rice straw composting, an aerobic composting experiment was conducted by setting three kinds of combined bacterial agents to study the tempera...In order to clarify the influence of microbial agents on kitchen waste and rice straw composting, an aerobic composting experiment was conducted by setting three kinds of combined bacterial agents to study the temperature change in the composting, and pH value, nutrient contents, C/N and heavy metal content after composting through. The three kinds of combined bacterial agents were as follows:B1 with effective strains: Bacillus subtilis, yeast and Trichoderma sp.;B2 with effective strains: Bacillus amyloliquefaciens, yeast and lactic acid bacteria;B3 with effective strains: Bacillus subtilis, yeast and lactic acid bacteria. Results showed that the addition of microbial agents had signifcant effects on temperature change,nitrogen and phosphorus content and C/N of the compost. T1, T2, and T3 treatments lasted for 8, 5 and 4 d in the thermophilic phase above 60℃, respectively. The total nitrogen content of each treatment was 14.90, 15.50 and 13.80 g/kg respectively after composting. The total phosphorus content of each treatment was 4.87, 4.17 and 3.70g/kg respectively at the end of composting. The C/N of each treatment was 20.94,22.63, and 22.65 respectively at the end of composting. The application effect of B1bacteria agent on the composting of kitchen waste and rice straw was better.展开更多
In Mexico, hazardous and non-hazardous urban solid wastes are commonly disposed of in dumps. Inappropriate waste disposal makes solid waste disposal sites potential sources of pollution and health risks. The objective...In Mexico, hazardous and non-hazardous urban solid wastes are commonly disposed of in dumps. Inappropriate waste disposal makes solid waste disposal sites potential sources of pollution and health risks. The objective of the present study was to evaluate the impact of leachate from a dump on surface water systems. Physical, chemical, and bacteriological characteristics and the volume of leachate were measured. The site of study is located in Zinaprcuaro, Michoac^m, Mexico, and was chosen due to the water supplies were in line with the dump, thus conforming a system to test for movement of toxins. Leachate and water from three ponds located at different distances to the dump were sampled during three months of a year to measure physicochemical and bacteriological parameters, according to the standard methods of the American Public Health Association; the concentration of heavy metals was measured by atomic absorption spectrometry. Most characteristics exceed the maximum permissible limits established for the Mexican legislation regarding wastewater discharges and drinking water. Likewise, analysis of variance showed statistically significant differences between concentrations of pollutants in relation to the distance from the dump of sampled sites and with season of sampling, thus confirming the contamination of water by dump leachate.展开更多
In this study, a in vessel aerobic composting method is adopted to investigate the variation rules of various evaluation parameters (temperature, moisture content, pH, organic matter, water soluble ammonia nitrogen, ...In this study, a in vessel aerobic composting method is adopted to investigate the variation rules of various evaluation parameters (temperature, moisture content, pH, organic matter, water soluble ammonia nitrogen, water soluble nitrate nitrogen and germination index) in cocomposting of municipal sludge, kitchen waste and water hyacinth at different proportions. The results show that, in composting, the parameters of moisture content, pH, water soluble ammonia nitrogen and water soluble nitrate nitrogen demonstrate marked dynamic change rules during composting process; the temperature of three groups of compost materials rapidly rise to above 55 ~C within 96h, and last for 3 - 7d, meeting the harmless requirements, and their organic matter degradation rate excess 30%, the GI index is higher than 83%, in line with the requirements on maturity, which proves that the co-composting of municipal sludge, kitchen waste and water hyacinth can realize harmlessness and resource reutilization after composting.展开更多
Biowaste compost can influence soil organic matter accumulation directly or indirectly. A 5-year experiment was conducted to assess the influence of biowaste compost on the process of soil aggregation and soil organic...Biowaste compost can influence soil organic matter accumulation directly or indirectly. A 5-year experiment was conducted to assess the influence of biowaste compost on the process of soil aggregation and soil organic carbon (SOC) accumulation in a Mediterranean vegetable cropping system. The study involved four treatments: biowaste compost (COM), mineral NPK fertilizers (MIN), biowaste compost with half-dose N fertilizer (COMN), and unfertilized control (CK). The SOC stocks were increased in COM, COMN, and MIN by 20.2, 14.9, and 2.4 Mg ha-1 over CK, respectively. The SOC concentration was significantly related to mean weight diameter of aggregates (MWD) (P 〈 0.05, R^2 = 0.798 4) when CK was excluded from regression analysis. Compared to CK, COM and COMN increased the SOC amount in macroaggregates (〉 250 μm) by 2.7 and 0.6 g kg-1 soil, respectively, while MIN showed a loss of 0.4 g kg-1 soil. The SOC amount in free microaggregates (53-250 ttm) increased by 0.9, 1.6, and 1.0 g kg-1 soil for COM, COMN, and MIN, respectively, while those in the free silt plus clay aggregates (~ 53 ~m) did not vary significantly. However, when separating SOC in particle-size fractions, we found that more stable organic carbon associated with mineral fraction 〈 53 μm (MOM-C) increased significantly by 3.4, 2.2, and 0.7 g kg-1 soil for COM, COMN, and MIN, respectively, over CK, while SOC amount in fine particulate organic matter (POM) fraction (53-250 μm) increased only by 0.3 g kg-1 soil for both COM and COMN, with no difference in coarse POM 〉 250 μm. Therefore, we consider that biowaste compost could be effective in improving soil structure and long-term C sequestration as more stable MOM-C.展开更多
A sequencing batch reactor (SBR) seeded with activated sludge was established for landfill leachate treatment. Small bio-aggregates began to appear after 40-d operation, and gradually changed to mature aerobic granu...A sequencing batch reactor (SBR) seeded with activated sludge was established for landfill leachate treatment. Small bio-aggregates began to appear after 40-d operation, and gradually changed to mature aerobic granules, with a mean size of 0.36-0.60 ram. Their sludge volume index at 5 min (SVI5 rain), mixed liquor volatile suspended solids (MLVSS), and wet density were around 35 ml/g, 3.4 g/L, and 1.062 g/cm3, respectively. The settling velocities of the granules in distilled water ranged from 0.3 to 1.3 cm/s, which were faster than those in landfill leachate with a salt content of 1.4% (w/v), and also slightly faster than those predicted by Stokes' law for porous but impermeable particles. Microbial community evolution during the granulation process and stages under different nitrogen loading rates (NLRs) were monitored and analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), cloning, and sequencing of 16S ribosomal RNA (rRNA) fragments. Results revealed that some primary and dominant communities in inoculating activated sludge died out gradually; while a few common bacteria, inhabiting soils, municipal wastewater, or activated sludge systems, dominated in the SBR system throughout. In addition, some other dominant species, associated with the aerobic granulation process, were thought to play a significant role in the formation and growth of aerobic granular sludge. During the stable operation time under low NLR, a few species were present in abundance, and may have been responsible for the high organic removal efficiency at this time.展开更多
基金Supported by Agricultural Scientific and Technological Achievement Transformation and Popularization Project of Tianjin(201003010)~~
文摘In order to investigate the influence of secondary classification mode on waste generation features, this study classified domestic waste generated by 310 rural and urban households at urban areas and Shuigaozhuang Village of Xiqing District into 3 groups: compostable materials, recyclable materials and toxics on the basis of the constructed secondary classification mode of domestic waste. The study focused on waste generation strength and classification features, compared the waste generation features between rural and urban residents, and analyzed the re- lation between waste generation strength and economic and cultural factors. The re- sults indicated that the average generation speed of urban domestic waste was 423.08 g/(d.capita), and that of rural domestic waste was 629.89 g/(d.capita), there was significant difference between rural and urban compost generation strength (P= 0.00002), while the generation strength of recyclable materials and toxics between rural and urban areas had no significant difference (P=0.471 and P=0.099, respec- tively). Secondary classification mode is an effective source classification mode for domestic wastes and has positive effects on waste reduction and treatment.
文摘On site composting of organic household wastes is an economical and environmentally tiiendly way to manage municipal wastes. In this manuscript authors evaluated the importance of turning the wastes and of inoculating microorganisms and worms in order to unprove the composting process at domestic scale. Four treatments (Control without turning- C-, Control with Turning- CT- inoculated Mountain Microorganism with turning- MM- and Worms without turning- W-) were tested in a random experiment with tour replicates. Sixteen composting bins were fed with 300 kg of organic wastes from a local street market. The process of compostnig lasted 13 weeks after which all the composts were sifted and submitted to a range of chemical, physical and biological analysis. According to the results MM slightly increased the initial temperature and enzymatic activiry. This investigation outcome don't provide of sufficient grounds for a precise recommendation about worms inoculation in compost bins. A decrease between 75% and 80% in the fresh weight of the organic waste was found in the first thirteen weeks after starting the composting process in all the treatments. The quality level of the compost was acceptable, with very low heavy metal content. Turn over helps to keep the product hygienic especially after the inoculation with MM microbial starts. In conclusion and according to the results of this investigation, the use of 320 L compost bins for the organic waste management is strongly advisable.
文摘The FAs (fulvic acids) belong to natural organic contaminants that are commonly found in different environments. In the process of oxidation and disinfection FAs are precursors of toxic substances, which cause a problem in many water treatment plants. In the sewage treatment plants, FAs are not biodegradable and together with purified wastewater and are discharged into surface waters. One of important source of the formation of FAs is the municipal landfill. In this thesis the authors test the amount of soluble fulvic acids present in the leachate of Barycz landfill in Krakow. The extracted FAs were subjected to a detailed analysis for the content of metals and IR spectrum analysis has also been done. Basing on elemental composition the C/O, C/H and C/N ratios have been determined. The obtained data were compared with the characteristics specified in the literature.
文摘In order to clarify the influence of microbial agents on kitchen waste and rice straw composting, an aerobic composting experiment was conducted by setting three kinds of combined bacterial agents to study the temperature change in the composting, and pH value, nutrient contents, C/N and heavy metal content after composting through. The three kinds of combined bacterial agents were as follows:B1 with effective strains: Bacillus subtilis, yeast and Trichoderma sp.;B2 with effective strains: Bacillus amyloliquefaciens, yeast and lactic acid bacteria;B3 with effective strains: Bacillus subtilis, yeast and lactic acid bacteria. Results showed that the addition of microbial agents had signifcant effects on temperature change,nitrogen and phosphorus content and C/N of the compost. T1, T2, and T3 treatments lasted for 8, 5 and 4 d in the thermophilic phase above 60℃, respectively. The total nitrogen content of each treatment was 14.90, 15.50 and 13.80 g/kg respectively after composting. The total phosphorus content of each treatment was 4.87, 4.17 and 3.70g/kg respectively at the end of composting. The C/N of each treatment was 20.94,22.63, and 22.65 respectively at the end of composting. The application effect of B1bacteria agent on the composting of kitchen waste and rice straw was better.
文摘In Mexico, hazardous and non-hazardous urban solid wastes are commonly disposed of in dumps. Inappropriate waste disposal makes solid waste disposal sites potential sources of pollution and health risks. The objective of the present study was to evaluate the impact of leachate from a dump on surface water systems. Physical, chemical, and bacteriological characteristics and the volume of leachate were measured. The site of study is located in Zinaprcuaro, Michoac^m, Mexico, and was chosen due to the water supplies were in line with the dump, thus conforming a system to test for movement of toxins. Leachate and water from three ponds located at different distances to the dump were sampled during three months of a year to measure physicochemical and bacteriological parameters, according to the standard methods of the American Public Health Association; the concentration of heavy metals was measured by atomic absorption spectrometry. Most characteristics exceed the maximum permissible limits established for the Mexican legislation regarding wastewater discharges and drinking water. Likewise, analysis of variance showed statistically significant differences between concentrations of pollutants in relation to the distance from the dump of sampled sites and with season of sampling, thus confirming the contamination of water by dump leachate.
文摘In this study, a in vessel aerobic composting method is adopted to investigate the variation rules of various evaluation parameters (temperature, moisture content, pH, organic matter, water soluble ammonia nitrogen, water soluble nitrate nitrogen and germination index) in cocomposting of municipal sludge, kitchen waste and water hyacinth at different proportions. The results show that, in composting, the parameters of moisture content, pH, water soluble ammonia nitrogen and water soluble nitrate nitrogen demonstrate marked dynamic change rules during composting process; the temperature of three groups of compost materials rapidly rise to above 55 ~C within 96h, and last for 3 - 7d, meeting the harmless requirements, and their organic matter degradation rate excess 30%, the GI index is higher than 83%, in line with the requirements on maturity, which proves that the co-composting of municipal sludge, kitchen waste and water hyacinth can realize harmlessness and resource reutilization after composting.
文摘Biowaste compost can influence soil organic matter accumulation directly or indirectly. A 5-year experiment was conducted to assess the influence of biowaste compost on the process of soil aggregation and soil organic carbon (SOC) accumulation in a Mediterranean vegetable cropping system. The study involved four treatments: biowaste compost (COM), mineral NPK fertilizers (MIN), biowaste compost with half-dose N fertilizer (COMN), and unfertilized control (CK). The SOC stocks were increased in COM, COMN, and MIN by 20.2, 14.9, and 2.4 Mg ha-1 over CK, respectively. The SOC concentration was significantly related to mean weight diameter of aggregates (MWD) (P 〈 0.05, R^2 = 0.798 4) when CK was excluded from regression analysis. Compared to CK, COM and COMN increased the SOC amount in macroaggregates (〉 250 μm) by 2.7 and 0.6 g kg-1 soil, respectively, while MIN showed a loss of 0.4 g kg-1 soil. The SOC amount in free microaggregates (53-250 ttm) increased by 0.9, 1.6, and 1.0 g kg-1 soil for COM, COMN, and MIN, respectively, while those in the free silt plus clay aggregates (~ 53 ~m) did not vary significantly. However, when separating SOC in particle-size fractions, we found that more stable organic carbon associated with mineral fraction 〈 53 μm (MOM-C) increased significantly by 3.4, 2.2, and 0.7 g kg-1 soil for COM, COMN, and MIN, respectively, over CK, while SOC amount in fine particulate organic matter (POM) fraction (53-250 μm) increased only by 0.3 g kg-1 soil for both COM and COMN, with no difference in coarse POM 〉 250 μm. Therefore, we consider that biowaste compost could be effective in improving soil structure and long-term C sequestration as more stable MOM-C.
基金Project supported by the National Water Pollution Control and Man-agement Project of China (No. 2009ZX07314-002)the Tianjin Science and Technology Development Program (No. 06YFGZSH06700)the Science and Technology Planning Project of Tianjin Binhai New Area, China (No. 2010-Bk130067)
文摘A sequencing batch reactor (SBR) seeded with activated sludge was established for landfill leachate treatment. Small bio-aggregates began to appear after 40-d operation, and gradually changed to mature aerobic granules, with a mean size of 0.36-0.60 ram. Their sludge volume index at 5 min (SVI5 rain), mixed liquor volatile suspended solids (MLVSS), and wet density were around 35 ml/g, 3.4 g/L, and 1.062 g/cm3, respectively. The settling velocities of the granules in distilled water ranged from 0.3 to 1.3 cm/s, which were faster than those in landfill leachate with a salt content of 1.4% (w/v), and also slightly faster than those predicted by Stokes' law for porous but impermeable particles. Microbial community evolution during the granulation process and stages under different nitrogen loading rates (NLRs) were monitored and analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), cloning, and sequencing of 16S ribosomal RNA (rRNA) fragments. Results revealed that some primary and dominant communities in inoculating activated sludge died out gradually; while a few common bacteria, inhabiting soils, municipal wastewater, or activated sludge systems, dominated in the SBR system throughout. In addition, some other dominant species, associated with the aerobic granulation process, were thought to play a significant role in the formation and growth of aerobic granular sludge. During the stable operation time under low NLR, a few species were present in abundance, and may have been responsible for the high organic removal efficiency at this time.