Earthworm biomass and population structure are negatively associated with changes in organic residue nitrogen concentration during vermicomposting

Vermicomposting is an efficient and environmentally friendly technology to dispose of agricultural organic residues.The efficiency of organic residue decomposition during vermicomposting is directly affected by the biomass and population structure of earthworms.In this study,we investigated how the earthworm biomass and population structure responded to changes in the physicochemical properties of six types of organic residue(cattle dung,herbal waste,rice straw,soybean straw,garden waste,and tea residues)during vermicomposting.Each type of organic residues was placed in a pot with earthworms Eisenia fetida,and the physicochemical properties of the organic residues and earthworm growth dynamics were recorded at 0,30,60,and 90 d of vermicomposting.The biomass and population structure of earthworms were stable or increased in rice straw,garden waste,and cattle dung within 60 d of vermicomposting,whereas in tea residues and herb waste,very little earthworm activity(3 adults and 2 cocoons)was recorded on day 30.Among the physicochemical parameters,the substrate C/N ratio was negatively correlated with earthworm growth dynamics.Decomposing organic residues showed higher NH_(4)^(+)-N and NH_(3)^(-)-N concentrations but a lower total organic carbon content,which negatively affected earthworm growth and reproduction.We recommend that chemical properties of vermicomposting systems should be monitored regularly.At the threshold levels of decomposing organic residue NH_(4)^(+)-N and NH_(3)^(-)-N concentrations,earthworms should be removed and the vermicompost can be harvested.Small-and large-scale farmers thus need to monitor the physicochemical properties of vermicompost to sustain active earthworm populations.

An Experimental Investigation of Fluidized Bed Gasification of Biomass Blended from Wood, Miscanthus, Straw and other Industrial Bioresidues

In order to identify potential wood substitutes for the production of energy by gasification, binary blends （wood/miscanthus, miscanthus/straw and wood/straw） and ternary blends （wood, miscanthus and organic residue） were systematic tested in a laboratory bubbling fluidized bed gasification system. The results of experiments were compared with results of wood gasification. Of the binary blends, wood and miscanthus exhibited great potential as a wood substitute in fluidized bed gasification in terms of process stability and product gas quality. Adding 10 wt. % of organic residues to form ternary blends further improved the product gas quality. Gasification of fuels blended with straw tended to agglomerate in the fluidized bed because of straw＇s low ash melting temperature. This can be counteracted by adding Ca（OH）2 to fuels. Nonetheless, fuels blended with straw with higher percentages of Ca（OH）2 need further study to establish the optimal additive ratio.

Humus Content in Soil and Yield in the Permanent Cotton Cultivated Fields

The article presents the data of a long-term experience on the reproductive capacity of the soil during the permanent cultivation of cotton, which has been carried out for 96 years at the Institute of Breeding, Seed Production and Agrotechnology for Growing Cotton in the Kibray district of the Tashkent region. The article presents the results of analyses by determining the content of humus, from which it can be seen that the decrease in humus was more marked on the control variant without fertilizers, and the amount of humus decreased after 20 years compared to the initial indicator by 11.4 t/ha, after 40 years 16 46 t/ha, after 60 years by 19.05 t/ha, after 80 years by 26.29 t/ha and after 96 years by 29.17 t/ha. It was also determined by the decrease in humus content in option 2, where NPK 250:175:125 kg/ha was applied annually, respectively: 6.487 t/ha;9.225 t/ha;10.09 t/ha;16.95 t/ha;19.65 t/ha;with an annual application of 30 t/ha of manure + 25 kg/ha of P2O in option 1, respectively: 0.335 t/ha;3.683 t/ha;11.40 t/ha;22.44 t/ha;32.58 t/ha. In addition, the article also provides data on the yield of cotton by options for permanent cultivation. It was determined that in the control variant, the yield decreased from 16.8 centners per hectare to 9.9 centners per hectare;in the variant where NPK was applied every year 250:175:125 kg/ha was 31 - 34 c/ha, where 30 t/ha of manure + 25 kg/ha P2O 29 - 32 c/ha were used every year.

Subsoil Natural Physico-chemical Reactor: The Property of Deep Abiogenic Methane-Containing High-Thermobaric Fluid to Form Coal Seams

For the first time,the property of deep abiogenic methane-containing high-thermobaric fluid to decompose organic residues in the Earth’s crust and form coal seams was established.

Effect of Land Use Pattern on Mineralization of Residual C and N from Plant Materials Decomposing Under Field Conditions

Four kinds of plant materials (astragalus, azolla, rice straw and water hyacinth) were allowed to decompose for 10 years in two soils with different mineralogical characteristics in fields under upland and submerged conditions. Greater amounts of C and N from azolla were retained in soils throughout the 10-year experimental period compared to those from the other plant materials. The residual C Of all the plant materials in the two soils under upland conditions mineralized st rates corresponding to half-lives between 4.4-6.6 years,while the corresponding figures for thine under submerged conditions were between 6.5-13.1 years. Minerallization of residual organic N followed the same pattern as residual C. Compared to residual C, however, the mineralization rates of residual organic N in most cases were significantly lower and the percentages of added N regained in sons were higher. More N from plat materials was retained in the yellow-brown soil than in the red soil, but no consistent differences in the amounts of C from plant materials and in the mineralization rates of both residual C and residual organic N between the two soils could be found.

Effects of residual organics in municipal wastewater on hydrogenotrophic denitrifying microbial communities

Hydrogenotrophic denitrification is promising for tertiary nitrogen removal from municipal wastewater. To reveal the influence of residual organics in municipal wastewater on hydrogenotrophic denitrifiers, we adopted high-throughput 16 S r RNA gene amplicon sequencing to examine microbial communities in hydrogenotrophic denitrification enrichments. Using effluent from a municipal wastewater treatment plant as water source, COD,nitrate and p H were controlled the same except for a gradient of biodegradable carbon（i.e., primary effluent（PE）, secondary effluent（SE）, or combined primary and secondary effluent（CE））. Inorganic synthetic water（IW） was used as a control. Hydrogenophaga, a major facultative autotroph, accounted for 17.1%, 5.3%, 32.7% and 12.9% of the sequences in PE, CE,SE and IW, respectively, implicating that Hydrogenophaga grew well with or without organics.Thauera, which contains likely obligate autotrophic denitrifiers, appeared to be the most dominant genera（23.6%） in IW and accounted for 2.5%, 4.6% and 8.9% in PE, CE and SE,respectively. Thermomonas, which is related to heterotrophic denitrification, accounted for 4.2% and 7.9% in PE and CE fed with a higher content of labile organics, respectively.In contrast, Thermomonas was not detected in IW and accounted for only 0.6% in SE. Our results suggest that Thermomonas are more competitive than Thauera in hydrogenotrophic denitrification with biodegradable organics. Moreover, facultative autotrophic denitrifiers,Hydrogenophaga, are accommodating to residual organic in effluent wastewater, thus we propose that hydrogenotrophic denitrification is amenable for tertiary nitrogen removal.

Study on the effects of organic matter characteristics on the residual aluminum and flocs in coagulation processes

Characteristics of organic matter may affect the residual aluminum after the coagulation process. This study reported the results of a survey for one drinking water treatment plant and measured the concentration of residual aluminum species with different molecular weights.Survey results indicated that humic acid or organic matter whose molecular weight was smaller than 1500 Da had significant effects on residual aluminum. All the treatment processes were ineffective in removing dissolved organic matter whose molecular weight was smaller than1500 Da. These results also indicated that the addition of sand or polyacrylamide in the coagulation process could greatly decrease the concentration of humic acid, and the concentration of residual aluminum also decreased. These results revealed that for all water samples after filtration, the majority of total residual aluminum existed in the form of total dissolved aluminum, accounting for 70%–90%. The concentration of residual aluminum produced in bovine serum albumin solutions indicated that when the DOC was larger than4.0 mg/L, there were still significant differences when the solution p H value varied from 4.0 to 9.0.

Removal of residual CuO particles on the post CMP wafer surface of multi-layered copper

This article introduces the removal technology of CuO particles on the post CMP wafer surface of multi-layered copper. According to the Cu film corrosion curve with different concentrations of HEO2 and the effect curve of time on the growth rate of CuO film, CuO film with the thickness of 220 nm grown on Cu a surface was successfully prepared without the interference of CuC12.2H20. Using the static corrosion experiment the type of chelating agent （FA/O II type chelating agent） and the concentration range （10-100 ppm） for CuO removal was determined, and the Cu removal rate was close to zero. The effect of surfactant on the cleaning solution properties was studied, and results indicated that the surfactant has the effect of reducing the surface tension and viscosity of the cleaning solution, and making the cleaning agent more stable. The influence of different concentrations of FA/O I type surfactant and the mixing of FA/O II type chelating agent and FA/O I type surfactant on the CuO removal effect and the film surface state was analyzed. The experimental results indicated that when the concentration of FA/O I type surfactant was 50 ppm, CuO particles were quickly removed, and the surface state was obviously improved. The best removal effect of CuO on the copper wiring film surface was achieved with the cleaning agent ratio of FA/O II type chelating agent 75 ppm and FA/O I type surfactant 50 ppm. Finally, the organic residue on the copper pattern film after cleaning with that cleaning agent was detected, and the results showed that the cleaning used agent did not generate organic residues on the film surface, and effectively removes the organic residue on the water.

Starch/polyvinyl alcohol blended materials used as solid carbon source for tertiary denitrification of secondary efuent

Starch/polyvinyl alcohol （PVA） blended materials for using as a solid carbon source （SCS） were prepared by blending PVA and gelatinized starch in an aqueous solution system, in which PVA served as framework material and starch as carbon source. The optimization of starch content and temperature effects were investigated. It was indicated that higher denitrification efficiency could be achieved with more starch in the materials. The average specific denitrification rates were 0.93, 0.66, 0.37 and 0.36 mg/（g·day） corresponding to starch content of 70%, 60%, 40% and 30% respectively at 37℃. The denitrification rates increased when operating temperature was raised from 23℃ to 30℃ and then 37℃. The mechanism of carbon release was analyzed incorporating the experimental results of abiotic release in deionized water. The organic carbon was mainly hydrolyzed by microbes, and the biological release efficiencies were at the range of 89.2% to 96.0%. A long-term experiment with a continuous flow reactor with SCS material containing 70% starch was conducted to gain some experience for practical application. When the influent nitrate concentration was in the range of 35.2 to 39.1 mg/L, hydraulic retention time of 4 hr, and operating temperature of 30℃, a nitrogen removal efficiency up to 94.6% and denitrification rate of 0.217 kg/（m3.day） was achieved. The starch-based materials developed in this study can be used as a solid carbon source for tertiary nitrogen removal from secondary effluent.

Conocarpus Biochar Induces Changes in Soil Nutrient Availability and Tomato Growth Under Saline Irrigation

Thermally modified organic materials commonly known as biochar have gained popularity of being used as a soil amendment.Little information, however, is available on the role of biochar in alleviating the negative impacts of saline water on soil productivity and plant growth. This study, therefore, was conducted to investigate the effects of Conocarpus biochar(BC) and organic farm residues(FR) at different application rates of 0.0%(control), 4.0% and 8.0%(weight/weight) on yield and quality of tomatoes grown on a sandy soil under drip irrigation with saline or non-saline water. The availability of P, K, Fe, Mn, Zn and Cu to plants was also investigated. The results demonstrated clearly that addition of BC or FR increased the vegetative growth, yield and quality parameters in all irrigation treatments. It was found that salt stress adversely affected soil productivity, as indicated by the lower vegetative growth and yield components of tomato plants. However, this suppressing effect on the vegetative growth and yield tended to decline with application of FR or BC, especially at the high application rate and in the presence of biochar. Under saline irrigation system, for instance, the total tomato yield increased over the control by 14.0%–43.3% with BC and by 3.9%–35.6% with FR. These could be attributed to enhancement effects of FR or BC on soil properties, as indicated by increases in soil organic matter content and nutrient availability. Therefore, biochar may be effectively used as a soil amendment for enhancing the productivity of salt-affected sandy soils under arid conditions.