Publications by authors named "Guo-Di Zheng"

32 Publications

[Spatial Distribution and Risk Assessment of Heavy Metal Pollution in Farmland Soils Surrounding a Typical Industrial Area of Henan Province].

Huan Jing Ke Xue 2021 Feb;42(2):900-908

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

In order to fully explore the spatial distribution of soil heavy metal contaminants in farmland soil surrounding a typical industrial area in Dakuai town, Xinxiang city, Henan Province, the concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn in the surface soil and within the soil profile were determined and assessed. The principal components were also analyzed for source apportionment to provide a theoretical basis for the control and prevention of heavy metal pollution. According to the results, the soils in the study area are severely contaminated by Cd and Cu and moderated contaminated by As due to the battery manufacture and Cu (e.g., pipe and wire) processing. The concentrations of Cd, Cu, and As in soils were (2.56±1.23) mg·kg, (205.58±157.49) mg·kg, and (15.27±4.14) mg·kg, respectively, which exceeds standards by 100%, 89.44%, and 3.40%, respectively. Accounting for the influence of pollution sources, terrain, runoff erosion, and prevailing wind direction, all heavy metal concentrations were higher in the south direction, lower in the north direction. The concentrations of Cd and Cu in soil profile samples decreased with depth, with highest concentrations at the surface, indicating the strong effect of industrial activities. Arsenic concentrations varied little with soil depth due to its strong migration ability in alkaline soil, again suggesting an industrial source. Among them, the soil of study area was severely contaminated by Cd and Cu (Level 5). Cd poses a severe potential ecological risk (Level 5) and Cu poses a medium risk (Level 2) in the study soils, while other heavy metals show low potential ecological risk (Level 1). The order of the risk identified was Cd > Cu > Ni > As > Pb > Cr > Zn. In addition, the combined potential ecological risk of heavy metals in the target area is severe. The principal component analysis showed that the high As, Cd, and Cu contents are mainly derived from industrial areas. Therefore, it is urgent to remediate Cd and Cu soil contamination in this area and implement precautions to limit As contamination.
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http://dx.doi.org/10.13227/j.hjkx.202005321DOI Listing
February 2021

Microbial degradation in the co-composting of pig manure and biogas residue using a recyclable cement-based synthetic amendment.

Waste Manag 2021 Mar 16;126:30-40. Epub 2021 Mar 16.

Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China. Electronic address:

This research investigated a synthetic amendment to improve composting and resource recycling of pig manure and biogas residue. We further examined whether adding a synthetic amendment impacts the microbial ecosystem in the composted materials. Three mixing ratios were used to investigate composting performance: no synthetic amendment (T0), 5% synthetic amendment (T1), and 10% synthetic amendment (T2) (T1 and T2 were measured as a wet weight ratio). There were no significant differences in the fundamental characteristics between composting products in T0 and T1. The moisture content of composting material in T0, T1, and T2 significantly decreased from a baseline of approximately 65% to 35.5%, 37.3%, and 55.9%, respectively. Meanwhile, the germination index significantly increased to 111.6%, 155.6%, and 62.3%, respectively. When an optimal proportion of synthetic amendment was added, T1 showed high degree of humification, lignocellulase activities, and effective biodegradation. Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes were the dominant bacteria, while Ascomycota and Basidiomycota were the dominant fungi in all treatment groups. Amino sugar and nucleotide sugar metabolism, glycolysis, starch, and sucrose metabolism were among the primary pathways in predicted functions. The synthetic amendment can generate a mature composting product and can be reused or recycled to conserve resources.
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http://dx.doi.org/10.1016/j.wasman.2021.02.036DOI Listing
March 2021

Microbial succession and degradation during kitchen waste biodrying, highlighting the thermophilic phase.

Bioresour Technol 2021 Apr 22;326:124762. Epub 2021 Jan 22.

School of Civil and Environmental Engineering, Ningbo University, 818 Fenghua Road, Ningbo 315211, China. Electronic address:

Biodrying in conjunction with compound stone amendment was used to treat kitchen waste, which improved biodrying. After 16 days, the pile moisture content decreased from 68.8% to 23.0%. Lignin, cellulose and hemicellulose concentrations decreased from 104.6 mg g d.b., 322.9 mg g d.b. and 155.9 mg g d.b., respectively, to 74.0 mg g d.b., 224.8 mg g d.b. and 134.5 mg g d.b., respectively. The Shannon index for bacteria increased from 2.5 to 3.1, while for fungi, it decreased from 4.6 to 0.6. The relative abundances of Amino Acid Metabolism and Carbohydrate Metabolism exceeded 7%. The thermophilic phase during the process inactivated the pathogenic microorganisms, increased the bacterial diversity, decreased the fungal diversity, and potentially improved the metabolism of nutrients, including amino acids, carbohydrates, lipids and vitamins. The biomarker analysis and predicated protein sequences provide genetic evidence to elucidate why the thermophilic phase is the peak time for nutrient metabolism.
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http://dx.doi.org/10.1016/j.biortech.2021.124762DOI Listing
April 2021

[Effect of Nutrient Regulation and Control on Cd Accumulation Efficiency of Under Field Conditions].

Huan Jing Ke Xue 2020 Sep;41(9):4226-4233

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

A field experiment with an orthogonally designed experiment L9(3) was designed to investigate the effect of different N, P, and K levels on plant growth and Cd uptake by . The results showed that the biomass of significantly increased with the N application rate. The highest dry weight in the shoot occurred in the treatments with a high level of N (337.5 kg ·hm), which was 0.86-2.00 times higher than the value with no fertilizer treatment. The addition of K contributed to promoting the Cd absorption of , while no effect was observed when N and P were added. Consequently, NPK fertilizers contribute to increasing the Cd uptake of , and the N and K fertilizer play important role in plant growth and Cd absorption respectively. Moreover, the effect of fertilizers on Cd uptake of was in the order of N > K > P, which indicated that N fertilizer was the main factor for promoting the Cd phytoextraction efficiency of by increasing the biomass. Therefore, the application of high levels of N combined with moderate levels of P and K will be an effective approach to improve the Cd phytoremediation efficiency of by promoting its growth, and the Cd uptake can be increased by a factor of 0.9-2.2 compared to no fertilizer treatment condition.
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http://dx.doi.org/10.13227/j.hjkx.202002199DOI Listing
September 2020

sp. nov., isolated from a deep well with oil reservoir water.

Int J Syst Evol Microbiol 2020 Jul;70(7):4339-4344

Key Laboratory of Soil Microbiology, Ministry of Agriculture, Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.

A Gram-stain-negative, rod-shaped bacterium, designated XJ4, was isolated from oil-contaminated water, collected from Xinjiang Province, north-west PR China (45° 1' 27″ N, 85° 6' 14″ E). Growth occurred at 20-45 °C (optimum, 30 °C) and pH 6.0-10.0 (optimum, pH 6.0-7.0). Strain XJ4 could tolerate up to 7 % (w/v) NaCl and grow optimally in the absence of NaCl. Phylogenetic analysis based on comparative sequence analysis of 16S rRNA gene sequences indicated that strain XJ4 belonged to the genus , and that was closely related to cai42 (97.2 %), SP32 (97.0 %) and JA296 (97.0 %). The average nucleotide identity values between XJ4 and three type strains were 77.9, 77.6 and 71.9 %, respectively. The DNA G+C content of strain XJ4 was 69.5 mol%. The sole respiratory quinone was Q-10. The major cellular fatty acid was summed feature 8 (Cω7 and/or Cω6), C and 11-methyl Cω7. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, unidentified phospholipids, an unidentified aminolipid and unidentified lipids. On the basis of phenotypic, chemotaxonomic and phylogenetic analyses, strain XJ4 represents a novel species of the genus , for which the name sp. nov. is proposed. The type strain is XJ4 (=CGMCC 1.13778=LMG 30952).
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http://dx.doi.org/10.1099/ijsem.0.004294DOI Listing
July 2020

Adding a recyclable amendment to facilitate sewage sludge biodrying and reduce costs.

Chemosphere 2020 Oct 10;256:127009. Epub 2020 May 10.

School of Civil and Environmental Engineering, Ningbo University, Ningbo, 315211, China. Electronic address:

Finding an economical amendment, available in a steady supply, is needed to support the biodrying industrialization. This research developed a recyclable biodrying amendment (RBA) to condition the biodrying of sewage sludge. The pilot-scale treatment (T), which included the addition of equivalent weights of RBA and sawdust as amendments, resulted in a higher pile temperature and longer thermophilic phase compared to the control (T), which used only sawdust as an amendment. The final moisture content levels were below 50% with both T and T. The heat use efficiency for water evaporation was 72.2% and 73.0% in T and T, respectively. The activity of α-amylase and cellulose 1,4-β-cellobiosidase increased during the thermophilic phase, while the activity of endo-1,4-β-glucanase and endo-1,4-β-xylanase decreased during the thermophilic phase with both T and T. The fourier-transform infrared spectra indicated that adding the RBA resulted in good biodegradability of the lipids, proteins, and polysaccharides. The humic acid to fulvic acid ratio in T and T increased from 0.33 (T) and 0.35 (T) on day 0-0.46 (T) and 0.45 (T) on day 21, indicating the humification process. The RBA recovery rate was 95.6% and can be reused. These findings highlight that adding RBA showed satisfactory biodrying performance, reduced the amendment cost, and the biodrying product could be incinerated without energy deficit.
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http://dx.doi.org/10.1016/j.chemosphere.2020.127009DOI Listing
October 2020

sp. nov., isolated from a deep well with oil reservoir water.

Int J Syst Evol Microbiol 2020 Apr 10;70(4):2312-2317. Epub 2020 Feb 10.

Key Laboratory of Soil Microbiology, Ministry of Agriculture, Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.

A Gram-stain-negative, non-motile and ovoid bacterial strain, designated 4-2, was isolated from oil-contaminated water which was collected from Xinjiang Province, north-west PR China. The 16S rRNA gene sequence analysis showed that strain 4-2 belonged to the genus . The species with highest similarity to strain 4-2 was YIM 90738 (97.83 %), followed by '' M26 (97.83 %) and SYSUP0003 (97.25 %). The average nucleotide identity values between 4-2 and three type strains were 84.69, 77.88 and 74.07 %, respectively. The genomic DNA G+C content of strain 4-2 was 61.4 mol%. Chemotaxonomical characteristic results showed that the respiratory quinone was ubiquinone Q-10 and the major fatty acids were summed feature 8 (C7 or C6) and C cyclo 8. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, unidentified phospholipids, an unidentified aminolipid and an unidentified polar lipid. The predominant polyamines were putrescine, cadaverine and spermidine. On the basis of phenotypic, chemotaxonomic and phylogenetic inferences, strain 4-2 represents a novel species of the genus , for which the name sp. nov. is proposed. The type strain is 4-2 (=CGMCC 1.13669=LMG 30882).
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http://dx.doi.org/10.1099/ijsem.0.004036DOI Listing
April 2020

[Effect of Fertilizers on Cadmium Uptake and Accumulation by Sunflowers].

Huan Jing Ke Xue 2018 Nov;39(11):5189-5197

Key Laboratory for Monitor and Remediation of Heavy Metal Polluted Soils of Henan Province, Jiyuan 459000, China.

A pot experiment was conducted to assess the phytoextraction potential for cadmium (Cd) of three types of sunflowers (edible, ornamental, and oil sunflowers) and the effects of the application of N, NP, and NPK fertilizers on Cd uptake of the three plants using Cd-contaminated soils collected from northern China. The results showed that fertilization could significantly increase the biomass, aboveground Cd concentrations and accumulation of ornamental and oil sunflowers, and the effect of NPK fertilizer was significantly better than those of other treatments. Cd concentrations of the aboveground parts of edible, ornamental, and oil sunflowers were 6.89, 8.92, 6.97 mg·kg, respectively. Fertilization treatment significantly improved the transport ability of Cd of the three types of sunflowers, and bioconcentration factors of edible, ornamental, and oil sunflowers were 2.63 (control) to 3.10 (NPK fertilizer), 2.80 (control) to 4.02 (NPK fertilizer), and 2.11 (control) to 3.14 (NPK fertilizer), respectively. The results further showed that the metal-enriched granules and cellular debris were the main enrichment sources in the subcellular fraction of the three types of sunflowers (more than 55%). In summary, sunflowers can be considered as plant material for remediation of Cd-contaminated soil. In addition, NPK fertilizers can effectively improve the efficiency of sunflowers.
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http://dx.doi.org/10.13227/j.hjkx.201804031DOI Listing
November 2018

[Sources and pollution characteristics of antibiotic resistance genes and conditional pathogenic bacteria in concentrated swine feeding operation.]

Ying Yong Sheng Tai Xue Bao 2018 Aug;29(8):2730-2738

College of Biological Sciences, China Agricultural University, Beijing 100094, China.

Air in concentrated animal feeding operations contains antibiotic resistance genes and airborne pathogens, with potential threat to human and animal health. In this study, air was sampled in the living area, outside, and inside of a fattening pig house in a pig farm for 24 and 48 hours. Feedstuffs, drinking water additives, and feces in the pig house were collected. Three kinds of antibiotic resistance genes (macrolide, β-lactam, and tetracycline) and seven pathogenic microorganisms (Campylobacter, Clostridium perfringens, Enterococcus, Escherichia coli, Yersinia enterocolitica, Staphylococcus spp., and Streptococcus suis) were detected by polymerase chain reaction (PCR). Six genes with high detection rates were selected, with their concentrations being determined by real-time quantitative PCR (qPCR). Results showed that three macrolide and two tetracycline resistance genes were detected in all air samples. Enterococcus, Escherichia coli, Yersinia enterocolitica, and Staphylococcus spp. were detected in air samples and drinking water additive. The concentrations of most target genes were above 10 copies·m. The gene concentrations near the pig house were much higher than those in the living area. Main sources of antibiotic resistance genes and pathogens in the air were pig manure and drinking water additive. Sampling time of 24 h in the pig farm met the requirements for PCR detection. Sampling time of 48 h had a higher sampling efficiency than that of 24 h in the living area of the pig farm, whereas sampling time of 24 h was more appropriate than that of 48 h in high bioaerosol concentration area such as the pig house.
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http://dx.doi.org/10.13287/j.1001-9332.201808.037DOI Listing
August 2018

Complete genome sequence provides insights into the biodrying-related microbial function of Bacillus thermoamylovorans isolated from sewage sludge biodrying material.

Bioresour Technol 2018 Jul 29;260:141-149. Epub 2018 Mar 29.

College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.

To enable the development of microbial agents and identify suitable candidate used for biodrying, the existence and function of Bacillus thermoamylovorans during sewage sludge biodrying merits investigation. This study isolated a strain of B. thermoamylovorans during sludge biodrying, submitted it for complete genome sequencing and analyzed its potential microbial functions. After biodrying, the moisture content of the biodrying material decreased from 66.33% to 50.18%, and B. thermoamylovorans was the ecologically dominant Bacillus, with the primary annotations associated with amino acid transport and metabolism (9.53%) and carbohydrate transport and metabolism (8.14%). It contains 96 carbohydrate-active- enzyme-encoding gene counts, mainly distributed in glycoside hydrolases (33.3%) and glycosyl transferases (27.1%). The virulence factors are mainly associated with biosynthesis of capsule and polysaccharide capsule. This work indicates that among the biodrying microorganisms, B. thermoamylovorans has good potential for degrading recalcitrant and readily degradable components, thus being a potential microbial agent used to improve biodrying.
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http://dx.doi.org/10.1016/j.biortech.2018.03.121DOI Listing
July 2018

Decomposition of lignocellulose and readily degradable carbohydrates during sewage sludge biodrying, insights of the potential role of microorganisms from a metagenomic analysis.

Chemosphere 2018 Jun 28;201:127-136. Epub 2018 Feb 28.

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing, 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address:

Sewage sludge biodrying is a waste treatment method that uses bio-heat generated from organic degradation to remove moisture from sewage sludge. Lignocellulose and carbohydrate decomposition is important when assessing biodrying performance. This study investigated lignocellulose and carbohydrate decomposition, and the potential microbial functions during biodrying. We determined the lignocellulose and carbohydrate contents, assayed related enzyme activity, performed a complete metagenomic study on sewage sludge biodrying material during the thermophilic phase, annotated potential genetic function involved in the decomposition, and summarized the key metabolic pathways. The results indicated that lignocellulose, readily degradable carbohydrates, and starch, significantly decomposed after biodrying. During the thermophilic phase, the majority of lignocellulose and carbohydrate-related enzymes showed significantly higher activity, and glycoside hydrolases and glycosyl transferases showed higher gene counts and reads. Moreover, the top five microorganisms enriched with carbohydrate-active enzyme genes, i.e., Bacillus, Intrasporangium, Tetrasphaera, Rhodobacter, and Streptomyces, were also among the top ten ecologically dominant genera. These findings highlight the crucial phases for biodrying process, reveal the ecologically functional diversity of biodrying-originated microbial consortia, and suggest potential candidates for optimizing biodrying decomposition.
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http://dx.doi.org/10.1016/j.chemosphere.2018.02.177DOI Listing
June 2018

[Emission Characteristics and Ozone Formation Potential of VOCs from a Municipal Solid Waste Composting Plant].

Huan Jing Ke Xue 2017 May;38(5):1783-1791

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

In Beijing, the chemical composition and component concentrations of volatile organic compounds (VOCs) were investigated during the municipal solid waste composting process using a portable gas chromatograph coupled with a mass spectrometer. The contributions of VOCs to the ozone formation potential were computed using the maximum incremental reactivity (MIR) scale and the propylene-equivalent concentration scale. The results showed that the concentrations of waste discharge in the sorting room, the first fermentation workshop, the second fermentation workshop, the compost product workshop, and the plant boundary were 10302.1, 15484.1, 929.9, 4693.6 and 370.4 μg·m, respectively. The main VOCs of the municipal solid waste composting plant were ethanol, limonene, and acetone. The propylene-equivalent concentrations of waste discharge in the sorting room, the first fermentation workshop, the second fermentation workshop, the compost product workshop, and the plant boundary were 25875.7, 4087.9, 378.0, 747.7 and 296.8 μg·m, whereas the O formation potentials computed using the MIR scale were 26979.3, 21168.3, 1469.3, 6439.6 and 455.8 μg·m. Reducing pollution by controlling the VOCs emission of waste discharge in the sorting room and the first fermentation workshop is important and can decrease the ozone formation potential. Given the accuracy and accessibility of the method, the MIR scale is more suitable for calculating the ozone formation potential of VOCs emitted from the municipal solid waste composting plant.
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http://dx.doi.org/10.13227/j.hjkx.201609210DOI Listing
May 2017

Reduction in greenhouse gas emissions from sludge biodrying instead of heat drying combined with mono-incineration in China.

J Air Waste Manag Assoc 2017 02;67(2):212-218

b Centre of Science and Technology of Construction , Ministry of Housing and Urban-Rural Development of China , Beijing , China.

Sludge is an important source of greenhouse gas (GHG) emissions, both in the form of direct process emissions and as a result of indirect carbon-derived energy consumption during processing. In this study, the carbon budgets of two sludge disposal processes at two well-known sludge disposal sites in China (for biodrying and heat-drying pretreatments, both followed by mono-incineration) were quantified and compared. Total GHG emissions from heat drying combined with mono-incineration was 0.1731 tCOe t, while 0.0882 tCOe t was emitted from biodrying combined with mono-incineration. Based on these findings, a significant reduction (approximately 50%) in total GHG emissions was obtained by biodrying instead of heat drying prior to sludge incineration.

Implications: Sludge treatment results in direct and indirect greenhouse gas (GHG) emissions. Moisture reduction followed by incineration is commonly used to dispose of sludge in China; however, few studies have compared the effects of different drying pretreatment options on GHG emissions during such processes. Therefore, in this study, the carbon budgets of sludge incineration were analyzed and compared following different pretreatment drying technologies (biodrying and heat drying). The results indicate that biodrying combined with incineration generated approximately half of the GHG emissions compared to heat drying followed by incineration. Accordingly, biodrying may represent a more environment-friendly sludge pretreatment prior to incineration.
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http://dx.doi.org/10.1080/10962247.2016.1227282DOI Listing
February 2017

Odor composition analysis and odor indicator selection during sewage sludge composting.

J Air Waste Manag Assoc 2016 09;66(9):930-40

c State Environmental Protection Key Laboratory of Odor Control , Tianjin , People's Republic of China.

Unlabelled: On the basis of total temperature increase, normal dehydration, and maturity, the odor compositions of surface and internal piles in a well-run sewage sludge compost plant were analyzed using gas chromatography-mass spectrometry with a liquid nitrogen cooling system and a portable odor detector. Approximately 80 types of substances were detected, including 2 volatile inorganic compounds, 4 sulfur organic compounds, 16 benzenes, 27 alkanes, 15 alkenes, and 19 halogenated compounds. Most pollutants were mainly produced in the mesophilic and pre-thermophilic periods. The sulfur volatile organic compounds contributed significantly to odor and should be controlled primarily. Treatment strategies should be based on the properties of sulfur organic compounds. Hydrogen sulfide, methyl mercaptan, dimethyl disulfide, dimethyl sulfide, ammonia, and carbon disulfide were selected as core indicators. Ammonia, hydrogen sulfide, carbon disulfide, dimethyl disulfide, methyl mercaptan, dimethylbenzene, phenylpropane, and isopentane were designated as concentration indicators. Benzene, m-xylene, p-xylene, dimethylbenzene, dichloromethane, toluene, chlorobenzene, trichloromethane, carbon tetrachloride, and ethylbenzene were selected as health indicators. According to the principle of odor pollution indicator selection, dimethyl disulfide was selected as an odor pollution indicator of sewage sludge composting. Monitoring dimethyl disulfide provides a highly scientific method for modeling and evaluating odor pollution from sewage sludge composting facilities.

Implications: Composting is one of the most important methods for sewage sludge treatment and improving the low organic matter content of many agricultural soils. However, odors are inevitably produced during the composting process. Understanding the production and emission patterns of odors is important for odor control and treatment. Core indicators, concentration indicators, and health indicators provide an index system to odor evaluation. An odor pollution indicator provides theoretical support for further modelling and evaluating odor pollution from sewage sludge composting facilities.
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http://dx.doi.org/10.1080/10962247.2016.1188865DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5062037PMC
September 2016

Simulation of water removal process and optimization of aeration strategy in sewage sludge composting.

Bioresour Technol 2014 Nov 8;171:452-60. Epub 2014 Jul 8.

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101, PR China.

Reducing moisture in sewage sludge is one of the main goals of sewage sludge composting and biodrying. A mathematical model was used to simulate the performance of water removal under different aeration strategies. Additionally, the correlations between temperature, moisture content (MC), volatile solids (VS), oxygen content (OC), and ambient air temperature and aeration strategies were predicted. The mathematical model was verified based on coefficients of correlation between the measured and predicted results of over 0.80 for OC, MC, and VS, and 0.72 for temperature. The results of the simulation showed that water reduction was enhanced when the average aeration rate (AR) increased to 15.37 m(3) min(-1) (6/34 min/min, AR: 102.46 m(3) min(-1)), above which no further increase was observed. Furthermore, more water was removed under a higher on/off time of 7/33 (min/min, AR: 87.34 m(3) min(-1)), and when ambient air temperature was higher.
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http://dx.doi.org/10.1016/j.biortech.2014.07.006DOI Listing
November 2014

Improvement of salinity in sewage sludge compost prior to its utilization as nursery substrate.

J Air Waste Manag Assoc 2014 May;64(5):546-51

Unlabelled: Soluble salts are enriched in sewage sludge compost because of their inherent derivation. Accordingly, the content of soluble salt in sludge compost is usually much higher than most seedlings can tolerate. To determine whether sludge compost is suitable for use as a nursery substrate, some experiments were conducted. Reduction of the electrical conductivity (EC) value could improve seed germination in saturated extract from sludge compost. In addition, water elution and mixing dilution with raw soil were all shown to be able to alleviate saline inhibition on seed germination and seedling growth, including stem diameter, seedling height, and above-ground weight. Overall, salinity is a crucial problem when sewage sludge compost is reused as a nursery substrate, and some effective and convenient approaches to reduce salt should be served prior to its reuse.

Implications: Sewage sludge after being composted is usually reused as organic fertilizer or plant substrate. However, salt is the main problem during its reclamation. What is the highest salt level the seedling can tolerate? Which types of salts are effective in salinity of sludge-amended substrate? Meanwhile, can the salinity be reduced through water elution or soil mixing dilution? This paper is the first to investigate the salinity and its reduction of sewage sludge compost prior to its use in the development of nursery substrate.
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http://dx.doi.org/10.1080/10962247.2013.872710DOI Listing
May 2014

Application of a recyclable plastic bulking agent for sewage sludge composting.

Bioresour Technol 2014 24;152:329-36. Epub 2013 Oct 24.

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101, PR China.

A recyclable plastic bulking agent (RPBA) that can be screened and reused was developed to improve sludge composting and to reduce costs. Two RPBAs were developed: RPBA35 (35 mm in diameter) and RPBA50 (50mm in diameter). The objective was to study the influence of size and quantity of RPBA on temperature, oxygen content, water removal during sludge composting, and phytotoxicity of the compost. RPBAs of both sizes improved the temperature, oxygen supply, and water removal compared with the treatment with no RPBA, and obtained phytotoxic-free compost. RPBA50 more effectively removed water than RPBA35. Oxygen diffusion rate in the composting pile containing RPBA50 was higher than in the treatment with no RPBA. When the RPBA50: sludge mixture ratio was above 1:1.5, the period over which the temperature exceeded 55 °C was insufficient to meet the harmless treatment requirement. The water evaporation rate was highest at a ratio of 1:2.
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http://dx.doi.org/10.1016/j.biortech.2013.10.061DOI Listing
August 2014

Influence of forced air volume on water evaporation during sewage sludge bio-drying.

Water Res 2013 Sep 18;47(13):4767-73. Epub 2013 Apr 18.

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101, PR China.

Mechanical aeration is critical to sewage sludge bio-drying, and the actual water loss caused by aeration can be better understood from investigations of the relationship between aeration and water evaporation from the sewage sludge bio-drying pile based on in situ measurements. This study was conducted to investigate the effects of forced air volume on the evaporation of water from a sewage sludge bio-drying pile. Dewatered sewage sludge was bio-dried using control technology for bio-drying, during which time the temperature, superficial air velocity and water evaporation were measured and calculated. The results indicated that the peak air velocity and water evaporation occurred in the thermophilic phase and second temperature-increasing phase, with the highest values of 0.063 ± 0.027 m s(-1) and 28.9 kg ton(-1) matrix d(-1), respectively, being observed on day 4. Air velocity above the pile during aeration was 43-100% higher than when there was no aeration, and there was a significantly positive correlation between air volume and water evaporation from day 1 to 15. The order of daily means of water evaporation was thermophilic phase > second temperature-increasing phase > temperature-increasing phase > cooling phase. Forced aeration controlled the pile temperature and improved evaporation, making it the key factor influencing water loss during the process of sewage sludge bio-drying.
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http://dx.doi.org/10.1016/j.watres.2013.03.048DOI Listing
September 2013

Time domain reflectometry measured moisture content of sewage sludge compost across temperatures.

Waste Manag 2013 Jan 22;33(1):12-7. Epub 2012 Oct 22.

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101, China.

Time domain reflectometry (TDR) is a prospective measurement technology for moisture content of sewage sludge composting material; however, a significant dependence upon temperature has been observed. The objective of this study was to assess the impacts of temperature upon moisture content measurement and determine if TDR could be used to monitor moisture content in sewage sludge compost across a range of temperatures. We also investigated the combined effects of temperature and conductivity on moisture content measurement. The results revealed that the moisture content of composting material could be determined by TDR using coated probes, even when the measured material had a moisture content of 0.581 cm(3)cm(-3), temperature of 70°C and conductivity of 4.32 mS cm(-1). TDR probes were calibrated as a function of dielectric properties that included temperature effects. When the bulk temperature varied from 20°C to 70°C, composting material with 0.10-0.70 cm(3)cm(-3) moisture content could be measured by TDR using coated probes, and calibrations based on different temperatures minimized the errors.
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http://dx.doi.org/10.1016/j.wasman.2012.09.014DOI Listing
January 2013

Moisture variation associated with water input and evaporation during sewage sludge bio-drying.

Bioresour Technol 2012 Aug 4;117:13-9. Epub 2012 Apr 4.

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101, PR China.

The variation of moisture during sewage sludge bio-drying was investigated. In situ measurements were conducted to monitor the bulk moisture and water vapor, while the moisture content, water generation, water evaporation and aeration water input of the bio-drying bulk were calculated based on the water mass balance. The moisture in the sewage sludge bio-drying material decreased from 66% to 54% in response to control technology for bio-drying. During the temperature increasing and thermophilic phases of sewage sludge bio-drying, the moisture content, water generation and water evaporation of the bulk initially increased and then decreased. The peak water generation and evaporation occurred during the thermophilic phase. During the bio-drying, water evaporation was much greater than water generation, and aeration facilitated the water evaporation.
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http://dx.doi.org/10.1016/j.biortech.2012.03.092DOI Listing
August 2012

Reducing H2S production by O2 feedback control during large-scale sewage sludge composting.

Waste Manag 2011 Jan;31(1):65-70

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101, China.

Hydrogen sulfide (H(2)S) production patterns and the influence of oxygen (O(2)) concentration were studied based on a well operated composting plant. A real-time, online multi-gas detection system was applied to monitor the concentrations of H(2)S and O(2) in the pile during composting. The results indicate that H(2)S was mainly produced during the early stage of composting, especially during the first 40 h. Lack of available O(2) was the main reason for H(2)S production. Maintaining the O(2) concentration higher than 14% in the pile could reduce H(2)S production. This study suggests that shortening the interval between aeration or aerating continuously to maintain a high O(2) concentration in the pile was an effective strategy for restraining H(2)S production in sewage sludge composting.
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http://dx.doi.org/10.1016/j.wasman.2010.08.020DOI Listing
January 2011

Simulation of substrate degradation in composting of sewage sludge.

Waste Manag 2010 Oct 15;30(10):1931-8. Epub 2010 May 15.

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101, PR China.

To simulate the substrate degradation kinetics of the composting process, this paper develops a mathematical model with a first-order reaction assumption and heat/mass balance equations. A pilot-scale composting test with a mixture of sewage sludge and wheat straw was conducted in an insulated reactor. The BVS (biodegradable volatile solids) degradation process, matrix mass, MC (moisture content), DM (dry matter) and VS (volatile solid) were simulated numerically by the model and experimental data. The numerical simulation offered a method for simulating k (the first-order rate constant) and estimating k(20) (the first-order rate constant at 20 degrees C). After comparison with experimental values, the relative error of the simulation value of the mass of the compost at maturity was 0.22%, MC 2.9%, DM 4.9% and VS 5.2%, which mean that the simulation is a good fit. The k of sewage sludge was simulated, and k(20), k(20s) (first-order rate coefficient of slow fraction of BVS at 20 degrees C) of the sewage sludge were estimated as 0.082 and 0.015 d(-1), respectively.
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http://dx.doi.org/10.1016/j.wasman.2010.04.004DOI Listing
October 2010

Pile settlement and volume reduction measurement during forced-aeration static composting.

Bioresour Technol 2008 Nov 8;99(16):7450-7. Epub 2008 Apr 8.

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, PR China.

In this study, a settlement measurement device was used to track the settlement of different layers in composting piles, and time courses of settlement velocity, bulk density distribution, and effective bulk density were investigated. Settlement is divided into two stages: the physical compressive settlement and the mass loss settlement. At the end of the former stage, bulk density (rho') and pile height (h) follow rho'=Ah(B), where A is a fitting parameter for the initial bulk density of the composting material, and B is the compression parameter. The physical compressibilities of composting mixtures are night-soil sludge and garden refuse (1:1) >sewage sludge and cornstalks (5:4) >night-soil sludge and garden refuse (2:3) >sewage sludge and bark (1:1). Adding the proportion of bulking agent in the proper extent effectively retarded composting settlement. Bark exhibits a better supporting capability than cornstalk does as a bulking agent.
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http://dx.doi.org/10.1016/j.biortech.2008.02.029DOI Listing
November 2008

[Contents and spatial distribution patterns of heavy metals in fFarmland soils of Fuxin City].

Ying Yong Sheng Tai Xue Bao 2007 Jul;18(7):1510-7

Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

A total of 180 farmland soil samples were collected from the suburbs of Fuxin City, Liaoning Province, to investigate the contents and spatial distribution patterns of Cu, Zn, As and Ni, with the effects of mining on their accumulation and spatial distribution in test farmland soils discussed. The results indicated that in study area, farmland soils had an accumulation of Cu, Zn and Ni, with the geometric mean concentrations higher than the background values. Among the soils planted with different crops, vegetable soil had significantly higher contents of Cu, Zn and As than grain crop soil. The spatial distribution of four test metals showed the same pattern of urban > suburban, and the regions with high concentrations of heavy metals were well overlapped with mining areas, suggesting that mining activities might be one of the most important source of heavy metals in the farmland soils. The rapid increase of animal manure also contributed to the import of pollutants to farmland soils to some degree. The potential risks of soil heavy metals pollution should be considered in the arrangement of local agricultural and animal husbandry productions.
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July 2007

Stabilization of nickel and chromium in sewage sludge during aerobic composting.

J Hazard Mater 2007 Apr 8;142(1-2):216-21. Epub 2006 Aug 8.

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, PR China.

The speciation of heavy metals can play a major role in the toxicity of those metals in sewage sludge following land application. Tessier sequential extraction was used to investigate the changes in Ni and Cr speciation in sewage sludge treated by forced-aeration composting. Ni and Cr concentrations increased 30.4% and 36.0%, respectively, during the composting process, with H(2)O and CO(2) volatilization being a major contributor to the change. It was found that the exchangeable, carbonate-bound, Fe-Mn oxide-bound, and organic matter-bound Ni and Cr were transformed to residual fractions. For Cr, the carbonate-bound, Fe-Mn oxide-bound, and organic matter-bound fractions were major contributors, while organic matter-bound Ni was a major contributor to the residual fraction. Composting appeared to reduce Ni and Cr availability by stabilizing the two metals and making them more stable and less mobile.
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http://dx.doi.org/10.1016/j.jhazmat.2006.08.003DOI Listing
April 2007

[Transformation of organic matter during thermophilic composting of pig manure].

Huan Jing Ke Xue 2006 May;27(5):986-90

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

Thermophilic composting of pig manure was studied in an attempt to elaborate upon organic matter transformation during the process and provided parameters for product maturity using chemical method. The following parameters were measured in 11 samples during the 42 days of composting: organic matter, dissolved organic carbon (DOC), degradable organic matter and humic matter (HM). Organic matter decreased during composting process constantly; DOC concentration increased to maximum at 10 days and declined thereafter; degradable organic matter decreased whole composting, but they increased in start of high-temperature stage; The increasing level of HM at various stages of composting indicate the progression of humification; H/F provide information correlating to conventional chemical parameters (organic matter, DOC) of compost maturity. Moreover, H/F has correlating to degradable organic matter and HM.
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May 2006

Changes of Cu, Zn, and Cd speciation in sewage sludge during connposting.

J Environ Sci (China) 2005 ;17(6):957-61

Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

The potential toxicity risks from heavy metals depend on their chemical speciation. The four stages of the Tessier sequential extraction method were employed to investigate changes in heavy metal speciation (Cu, Zn, and Cd) of sewage sludge during forced aeration composting, and then to identify whether the composting process would reduce or enhance their toxicities. Throughout the composting process, the exchangeable, carbonate-bound, Fe-Mn oxide-bound, and organic matter-bound fractions of Cu were converted to the residual Cu fraction. The organic matter-bound Cu fraction greatly contributed to this transformation. Residual Zn fraction was transformed to the Fe-Mn oxide-bound and organic matter-bound fractions after composting. The residual Zn fraction was a major contributor to the organic matter-bound Zn fraction. The availability of Cu and Zn was reduced by composting such that the risk of heavy metal toxicity decreased with prolonged treatment times. Additionally, attention should be paid to the increased availability of Cd in sewage sludge after composting treatment.
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September 2006

[Stratification of free air space and its dynamics in the process of co-composting].

Huan Jing Ke Xue 2004 Nov;25(6):150-3

Center for Environmental Remediation, Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

Co-composting of sewage sludge and pig manure was studied. Free air space (FAS) in the whole composting pile was 26.2% at the temperature rising stage and 42.3% at the stage of high temperature composting. FAS in the upper portion of composting pile was higher than that in the lower, where the air was enough for microorganism to live on for two stages above. The FAS was 52.4% at the stage of the cooling, when the effect of stratification of FAS was significant. The FAS in the upper pile was bigger than that in the middle, which was bigger than that in the lower. At the stageof maturing, FAS was 54.7% and its stratified effect weakened, but the capability of aeration in the upper and in the middle of the pile was larger than that in the lower. At the different stages of composting, the degree of difference of FAS was of the order: the cooling stage > the high temperature stage > maturing stage > the temperature rising stage. The difference in the pile for every stage of composting was as follows: the upper > the middle > the lower. The change of FAS agreed with two-order kinetics.
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November 2004

[Background concentrations of soil heavy metals in Beijing].

Huan Jing Ke Xue 2004 Jan;25(1):117-22

Laboratory of Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

Soil background concentrations of heavy metals are important criterion for the assessment of soil environmental quality. The background concentrations of soil heavy metals, As, Cd, Cr, Cu, Ni, Pb and Zn, were investigated based on an extensive investigation conducted in the whole area of Beijing. About 120 soil samples taken from the area without pollution of heavy metals were selected from the total 803 soil samples. After analyzing the samples with strict quality assure and quality control (QA/QC) procedures, the heavy metal concentrations in the soils were calculated using statistical method. The revised background concentrations of the soils in Beijing are proposed to be 7.09 mg/kg for As, 0.119 mg/kg for Cd, 29.8 mg/kg for Cr, 18.7 mg/kg for Cu, 26.8 mg/kg for Ni, 24.6 mg/kg for Pb, 57.5 mg/kg for Zn, respectively. Compared with the concentrations suggested by China National Environmental Monitoring Center (CNEMC) in 1990, the Cd background concentration suggested in present study is about 125% higher than that of CNEMC, and the As, Cr, Cu, Zn concentrations are 19%-55% lower than those of CNEMC, while the concentrations of Pb and Ni are not obviously different from those of CNEMC.
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January 2004

[Stratification of volatile solid content and its dynamics in the process of co-composting].

Huan Jing Ke Xue 2004 May;25(3):155-9

Laboratory of Environmental Remediation, Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

Co-composting of sewage sludge and pig manure was conducted and it was indicated that, at the stages of temperature starting and high temperature composting, the difference of organic decomposition in the upper portion was largest among three portions of composting pile. The difference was largest in the lower part of the pile and the stratification effect of volatile solid (VS) content was formed at the stage of cooling, while it was largest in the middle and the stratification effect was still remarkable at the stage of maturity. At different stages of composting, the difference of VS content in the pile was of the order: the cooling > or = the maturity > the high temperature > the temperature starting. At each stage of composting, the difference of organic decomposition in the pile was as follows: the upper > the middle > the lower. The change of VS content met with first-order kinetics equation and decomposition rate of VS was 0.3 kg x d(-1) while average loss of VS content was 8.2% in the whole process of composting.
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May 2004