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Characteristics of volatile compounds removal in biogas slurry of pig manure by ozone oxidation and organic solvents extraction

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Journal of environmental Sciences 2013年第9期25卷 1800-1807页

作者： Yujun Wang Lianshuang Feng Xiaosong Zhao Xiulan Ma Jingmin Yang Huiqing Liu Sen Dou Miping Zhou Zhonglei Xie College of resources and environment Jilin Agricultural University Development College Jilin Agricultural University College of environment and resources Jilin University

Biogas slurry is not suitable for liquid fertilizer due to its high amounts of volatile materials being of complicated composition and peculiar smell. In order to remove volatiles from biogas slurry efficiently, the dynamic headspace and gas chromatography-mass spectrometry were used to clear the composition of volatiles. Nitrogen stripping and superfluous ozone were also used to remove volatiles from biogas slurry. The results showed that there were 21 kinds of volatile compounds in the biogas slurry, including sulfur compounds, organic amines, benzene, halogen generation of hydrocarbons and alkanes, some of which had strong peculiar smell. The volatile compounds in biogas slurry can be removed with the rate of 53.0% by nitrogen stripping and with rate of 81.7% by the oxidization and stripping of the superfluous ozone. On this basis, the removal rate of the volatile compounds reached 99.2% by chloroform and n-hexane extraction, and almost all of odor was eliminated. The contents of some dissolved organic compounds decreased obviously and however main plant nutrients had no significant change in the biogas slurry after being treated.

关键词： biogas slurry dynamic headspace removal volatile compounds plant nutrients

Applying a new method for direct collection, volume quantification and determination of N_2 emission from water

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Journal of environmental Sciences 2015年第1期27卷 217-224页

作者： Xinhong Liu Yan Gao Honglian Wang Junyao Guo Shaohua Yan Institute of agricultural resources and environment Jiangsu Academy of Agricultural Sciences College of resources and environmental Science Nanjing Agricultural University

The emission of N2 is important to remove excess N from lakes, ponds, and wetlands. To investigate the gas emission from water, Gao et al.（2013） developed a new method using a bubble trap device to collect gas samples from waters. However, the determination accuracy of sampling volume and gas component concentration was still debatable. In this study, the method was optimized for in situ sampling, accurate volume measurement and direct injection to a gas chromatograph for the analysis of N2 and other gases. By the optimized new method, the recovery rate for N2 was 100.28% on average; the mean coefficient of determination（R2） was 0.9997; the limit of detection was 0.02%. We further assessed the effects of the new method, bottle full of water, vs. vacuum bag and vacuum vial methods, on variations of N2 concentration as influenced by sample storage times of 1,2, 3, 5, and 7 days at constant temperature of 15°C, using indices of averaged relative peak area（%） in comparison with the averaged relative peak area of each method at 0 *** indices of the bottle full of water method were the lowest（99.5%–108.5%） compared to the indices of vacuum bag and vacuum vial methods（119%–217%）. Meanwhile, the gas chromatograph determination of other gas components（O2, CH4, and N2O） was also accurate. The new method was an alternative way to investigate N2 released from various kinds of aquatic ecosystems.

关键词： New method N2 Ebullition collection Direct injection Gas chromatograph

Arsenite oxidation by three types of manganese oxides

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Journal of environmental Sciences 2006年第2期18卷 292-298页

作者： FENG Xiong-han ZU Yan-qun TAN Wen-feng LIU Fan College of resources and environment Huazhong Agricultural University Wuhan 430070 China College of resources and environment Yunnan Agricultural University Kunming 650201 China

Oxidation of As（Ⅲ） by three types of manganese oxides and the effects ofpH, ion strength and tartaric acid on the oxidation were investigated by means of chemical analysis, equilibrium redox, X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Three synthesized Mn oxide minerals, bimessite, cryptomelane, and hausmannite, which widely occur in soil and sediments, could actively oxidize As（Ⅲ） to As（Ⅴ）. However, their ability in As（Ⅲ）-oxidation varied greatly depending on their structure, composition and surface properties. Tunnel structured cryptomelane exhibited the highest ability of As （Ⅲ） oxidation, followed by the layer structured birnessite and the lower oxide hausmannite. The maximum amount of As （Ⅴ） produced by the oxidation was in the order （mmol/kg） of cryptomelane （824.2）〉 bimessite （480.4）〉 hausmannite （117.9）, As pH increased from the very low value（pH 2.5）, the amount of As（Ⅲ） oxidized by the tested Mn oxides was firstly decreased, then negatively peaked in pH 3.0 6.5, and eventually increased remarkably. Oxidation of As（Ⅲ） by the Mn oxides had a buffering effects on the pH variation in the solution. It is proposed that the oxidative reaction processes between As （Ⅲ） and biruessite（or cryptomelane） are as follows：（1） at lower pH condition：（MnO2）x＋ H3AsO3 ＋ 0.5H^＋=0.5H2AsO4^- ＋ 0.5HAsO4^2- ＋Mn〉^2＋（MnO2）x-1 ＋ H2O; （2） at higher pH condition：（MnO2）x ＋ H3AsO3 = 0.5H2AsO4^- ＋ 0.5HAsO4^2- ＋ 1.5H^＋＋（MnO2）x-1. MnO. With increase of ion strength, the As（Ⅲ） oxidized by bimessite and cryptomelane decreased and was negatively correlated with ion strength. However, ion strength had little influence on As （Ⅲ） oxidation by the hausmarmite. The presence of tartaric acid promoted oxidation of As（Ⅲ） by birnessite. As for cryptomelane and hansmannite, the same effect was observed when the concentration of tartaric acid was below 4 mmol/L, otherwise the oxidized As（Ⅲ） decreased. These findings are of great significance in improving our understanding

关键词： oxidation of As(Ⅲ) As(Ⅴ) Mn oxides pH ion strength tartaric acid

Photocatalytic degradation of pesticide residues with RE^(3+)-doped nano-TiO_2

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Journal of Rare Earths 2010年第S1期28卷 353-356页

作者：曾睿王敬国崔建宇胡林慕康国 Department of resources and environment China Agricultural University

The photocatalytic degradation effects of carbofuran solution under concentration of 0.2,0.4,0.8 g/L Re3+-doped nano-TiO2 were *** highest degradation rate of 54.89% was obtained after 4 h degradation when the concentration of nano-TiO2 was 0.4 g/*** field trials of photocatalytic degradation with suspension nano-TiO2 were *** photocatalytic degradation effect of organic phosphorus and carbamate pesticides in tomato leaves and soil with different concentratio catalyst(0,0.2,0.4,0.6,0.8 g/L) were *** results showed that nano-TiO2 could significantly increase photocatalytic degradation rate of pesticide residues in tomato leaves and *** residues degradation rate could be increased by 20%-30% on the tomato leaves and 15%-20% in soil,and the best concentration of photocatalytic degradation was 0.2-0.4 g/L.

关键词： nano-TiO2 photo catalytic degradation pesticide residue organic phosphorus carbonate

Mechanism of Cu(Ⅱ) adsorption inhibition on biochar by its aging process

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Journal of environmental Sciences 2014年第10期26卷 2123-2130页

作者： Yue Guo Wei Tang Jinggui Wu Zhaoqin Huang Jingyu Dai College of resources and environmental Sciences Nanjing Agricultural University College of resources and environment Jilin Agricultural University

Biochar exposed in the environment may experience a series of surface changes, which is called biochar aging. In order to study the effects of biochar aging on Cu（Ⅱ） adsorption, we analyzed the surface properties before and after biochar aging with scanning electron microscopy（SEM） coupled to an energy-dispersive X-ray spectrometer（EDX） and diffuse reflectance infrared Fourier transform spectroscopy（DRIFTS）, and then explored the influence of the aging process on Cu（Ⅱ） adsorption by batch experiments. After the aging process, the oxygen concentration, phenolic hydroxyl groups, aromatic ethers and other oxygen-containing functional groups on the biochar surface increased, while carboxyl groups slightly decreased. Thus, over a range of pH, the cation exchange capacity（CEC） and adsorption capacity of Cu（Ⅱ） on the aged biochar were smaller than those of new biochar,indicating that when biochar is incubated at constant temperature and water holding capacity in the dark, the aging process may inhibit Cu（Ⅱ） adsorption. Meanwhile, the dissociation characteristics of oxygen-containing functional groups changed through the aging process, which may be the mechanism by which the biochar aging process inhibits the Cu（Ⅱ） adsorption. Carboxyl groups became more easily dissociated at low pH（3.3–5.0）,and the variation of maximum adsorption capability（qm） of Cu（Ⅱ） on the old biochar was enlarged. Phenolic hydroxyl groups increased after the aging, making them and carboxyl groups more difficult to dissociate at high pH（5.0–6.8）, and the variation of qmof Cu（Ⅱ） on the aged biochar was reduced.

关键词： Biochar Aging Surface property Adsorption Cu(Ⅱ)

Cadmium-Resistant Oyster Mushrooms from North China for Mycoremediation

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Pedosphere 2018年第6期28卷 848-855页

作者： CHEN Miaomiao ZHENG Xin CHEN Liang LI Xiaofang Key Laboratory of agricultural Water resources Centre for Agricultural Resources Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences environment centre Sustainable Minerals Institute The University of Queensland

Macrofungi have been advocated to be a promising remediation material for heavy metal pollution. This study aimed to screen for cadmium(Cd)-tolerant oyster mushroom strains which may be used as biomaterials for Cd remediation in North China. To this end, 43 oyster mushroom strains were collected across North China and subject to Cd inhibition test. Phylogenetic affiliation of the tolerant strains was identified using molecular fingerprinting, and representative Cd-tolerant strains were characterized in terms of their Cd sorption capacity. Two strains, JINONG21 and SUYIN6 affiliated with Pleurotus ostreatus, were found to be highly tolerant to Cd, with a minimal inhibitory concentration of 4 mg L^(-1) Cd and a maximal tolerant concentration of 80 mg L^(-1) Cd under the test conditions. Meanwhile, JINONG21 and SUYIN6 were able to absorb up to 676 mg kg^(-1) and 970 mg kg^(-1) Cd in their mycelia in the culture medium with 20 mg L^(-1) Cd, respectively. In conclusion, the P. ostreatus strains identified in this study presented an outstanding capacity of Cd tolerance and sorption and could be promising biomaterials for Cd remediation in North China.

关键词： bioaccumulation heavy metal macrofungi maximal tolerant concentration Pleurotus ostreatus remediation sorption capacity tolerant strain

Cultivation Ages Effect on Soil Physicochemical Properties and Heavy Metal Accumulation in Greenhouse Soils

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Chinese Geographical Science 2018年第4期28卷 717-726页

作者： WANG Jun MI Wenkui SONG Peipei XIE Hui ZHU Lusheng WANG Jinhua College of resources and environment Key Laboratory of Agricultural Environment in Universities of Shandong Shandong Agricultural University

The intensive management practices in greenhouse production may alter the soil physicochemical properties and contribute to the accumulation of heavy metals(HMs). To determine the HM concentrations in vegetable soil in relation to soil physicochemical properties and cultivation age, we conducted a soil survey for typical greenhouse soils in Shouguang, China. The results indicated that Cd is a major HM pollutant in the tested soils, as the only HM element exceeding the allowed limit for vegetable soil. The surveyed data was analyzed with regression analysis, correlation analysis and canonical correspondence analysis(CCA). A positive correlation is observed between HM pollution level and cultivation age. CCA results suggest that the HM pollution level and distribution in soil are significantly affected by soil physicochemical properties, which was a function of years of cultivation as revealed by regression analysis. In summary, cultivation age is an important factor to affect soil physicochemical properties(organic matter and inorganic nutrients) as well as HM contamination.

关键词： heavy metal greenhouse soil cultivation age physicochemical property canonical correspondence analysis (CCA)

Crop Yield and Soil Properties in the First 3 Years After Biochar Application to a Calcareous Soil

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Journal of Integrative Agriculture 2014年第3期13卷 525-532页

作者： LIANG Feng LI Gui-tong LIN Qi-mei ZHAO Xiao-rong College of resources and environment China Agricultural University

It remains unclear whether biochar applications to calcareous soils can improve soil fertility and crop yield. A long-term field experiment was established in 2009 so as to determine the effect of biochar on crop yield and soil properties in a calcareous soil. Five treatments were： 1） straw incorporation; 2） straw incorporation with inorganic fertilizer; 3）, 4） and 5） straw incorporation with inorganic fertilizer, and biochar at 30, 60, and 90 t ha-l, respectively. The annual yield of either winter wheat or summer maize was not increased significantly following biochar application, whereas the cumulative yield over the first 4 growing seasons was significantly increased. Soil pH, measured in situ, was increased by a maximum of 0.35 units after 2 yr following biochar application. After 3 yr, soil bulk density significantly decreased while soil water holding capacity increased with adding biochar of 90 t ha^-1. Alkaline hydrolysable N decreased but exchangeable K increased due to biochar addition. Olsen-P did not change compared to the treatment without biochar. The results suggested that biochar could be used in calcareous soils without yield loss or significant impacts on nutrient availability.

关键词： biochar calcareous soil crop yield soil pH long-term effect

Effects of Long-Term Groundwater Management and Straw Application on Aggregation of Paddy Soils in Subtropical China

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Pedosphere 2015年第3期25卷 386-391页

作者： YIN Li-Chu ZHANG Lei YI Ya-Nan LUO Lan-Fang College of resources and environment Hunan Agricultural University

Soil organic carbon （SOC） and iron （Fe）-oxides are important contributors of aggregate stability in highly weathered soils, and they are influenced by groundwater management and straw application. A 30-year plot experiment with early rice （Oryza sativa L.）-late rice-winter fallow rotations was conducted using a upland clay soil in cement pools under shallow groundwater table at a depth of 20 am （SGT） aud deep groundwater table at a depth of 80 cm （DGT） to simulate the groundwater tables of two types of important paddy soils, gleyed paddy soils and hydromorphic paddy soils, respectively, in subtropical China. Soil redox potential （Eh） was measured in situ, and 0-20 cm soil samples were collected for the analyses of soil Fe-oxides, SOC, and aggregates under SGT or DGT with different straw application treatments, in order to evaluate the interaction of groundwater management and straw application on paddy soil aggregation and the relative importance of SOC or Fe-oxides on soil aggregation. The results showed that soil Eh was restricted by irrigation, and its variation was more significant under DGT than under SGT. The decreased soil Eh or reduced drying and wetting cycles under SGT resulted in more SOC accumulation with the straw application, had no effect on soil free Fe-oxides （Fed）, significantly increased the amorphous Fe-oxide （Feo） and complex Fe-oxide contents, but decreased the crystalline Fe-oxide content （Fed-Feo）. The soils under DGT had more macroaggregates than those under SGT, but the difference decreased with the straw application. It could be concluded that soil Fe-oxides were the principal contributing factor to the aggregation of paddy soils in subtropical China and SOC was also an important contributing factor.

关键词： groundwater table Fe-oxides long-term experiment rice soil organic carbon