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771.
772.
Adsorption of Ammonium by Graphene Oxide-Based Composites Prepared by UV Irradiation and Using as Slow-Release Fertilizer 总被引:1,自引:0,他引:1
Chengyi Wu Xu Zhang Cong Li Chao Cheng Yin Zheng 《Journal of Polymers and the Environment》2018,26(12):4311-4320
A novel sodium alginate-grafted poly(acrylic acid)/graphene oxide (NaAlg-g-PAA/GO) composite hydrogel was prepared via ultraviolet irradiation, and characterized by infrared spectroscopy spectrometer. X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. It was employed to adsorb NH4+ from aqueous solution and used as slow-release nitrogen fertilizers (SNFs). Result indicated that the adsorption process for NH4+ reached equilibrium within 50 min, with the adsorption capacity of 6.6 mmol g?1 even if 30 wt% GO was incorporated. The results of adsorption kinetic and isotherm were well described by the pseudo-second-order and Freundlich model. The thermodynamics analysis showed the adsorption process was spontaneous. The study indicated excellent water-holding ratio of soil with 2 wt% SNFs was 81.2%, and nitrogen release was up to 55.1% within 40 days in soil. Overall, NaAlg-g-PAA/GO could be considered as an efficient adsorbent for the recovery of nitrogen with the agronomic reuse as a fertilizer. 相似文献
773.
774.
Optimization of low-temperature drying of laying-hen manure using response surface methodology 总被引:1,自引:0,他引:1
Xuanyang Li Weichao Zheng Qin Tong 《Journal of the Air & Waste Management Association (1995)》2020,70(2):206-218
ABSTRACTManure-drying system using exhausted air from laying hen houses or ambient air has been extensively used in China to dewater the manure for easy transportation and to reduce pathogen levels prior to land application. Due to the climate influence or inappropriate setting of technological parameters, there are some issues in this manure-drying system, such as low dehydration rate, high energy consumption, and high ammonia emission. A purpose-designed experimental drying apparatus was set up to simulate the commercial manure drying system. Drying experiments were carried out to assess the impacts of hot air temperature (15–35°C), air velocity (0.6–1.8 m/s) and manure layer thickness (60–140 mm) on fan’s energy consumption, dehydration rate, and nitrogen loss rate. The response surface analysis method and sub-stepping method was used to analyze the relationships between the response variables and the influence factors. The drying curves were drawn, and the quadratic regression mathematical models that described the relations between the experimental indices and the influence factors were established. The optimal combination of technological parameters for drying laying-hen manure was obtained through conducting a multi-objective function optimization by function-expected optimization. The optimal parameters are as follows: hot air temperature of 35°C, air velocity of 1.60 m/s, and manure layer thickness of 85 mm. The results also indicate that raising the hot air temperature increased the value of synthesis objective function when the hot air temperature was in 26–35°C. The results can provide a theoretical basis for low-temperature drying of laying-hen manure in actual production.Implications: A large amount of poultry manure is produced yearly in China, which has become a tremendous pressure on the environment when it cannot be utilized as resources. A more sustainable solution using the residual heat from the poultry house ventilation or ambient hot air has been widely used in China. This drying method can significantly reduce energy consumption compared to the traditional way. However, due to the influence of climate or inappropriate setting of technological parameters, issues such as high energy consumption and high ammonia emission still exist in this method. It is necessary to optimize the low-temperature drying process of laying-hen manure, to reduce energy consumption and nitrogen loss rate. 相似文献
775.
Xinyan Guo Lv Xiaojun Aiguo Zhang Zheng Yan Siyi Chen 《Journal of environmental science and health. Part. B》2020,55(3):193-209
AbstractThe occurrence and distribution in the aquatic environment of Nanjing of 49 antibiotics from seven therapeutic classes were investigated using an improved analytical method developed for multiclass target analysis. The results showed that these antibiotics are widely present in the water bodies of this city, with a total concentration of up to 1.958?μg L?1. The most abundant class was tetracyclines, contributing 43.7% to the total antibiotic burden. Lincomycin was detected in all samples, and the detection rate of clindamycin was 90.5%. An exploratory analysis of the data points was performed by unsupervised pattern recognition (hierarchical cluster analysis, HCA) in an attempt to clarify the pollution level in different sampling areas, and robust cluster solutions grouped the data according to their different antibiotic contaminant profiles. The safety of drinking water resources was emphasized, and the rivers, as the main receiving water body for treated and untreated wastewater in this city, were more seriously contaminated than the surrounding lakes and reservoir, not only in concentration but also in detection frequency, in our study as well as in similar research studies. A correlation analysis between the presence of antibiotics and the environmental factors was conducted, and it was found that antibiotic contamination and water quality were closely connected; the better the water quality, the lower the antibiotic contamination. Positive correlations existed between the antibiotics and tested heavy metals, as well as between antibiotics and boron and arsenic. However, whether these correlations resulted from their reaction or a common source was difficult to determine, and the mechanism requires further exploration. 相似文献
776.
Ma Yuhui Zheng Peiru Dai Wanqing Zheng Xiangyong He Shengbing Zhao Min 《Environmental science and pollution research international》2020,27(34):42571-42581
Environmental Science and Pollution Research - Constructed ditch wetland (CDW) is a combination of idle ditch and constructed wetland, which is typically used in rural areas to remove pollutants... 相似文献
777.
Yan Fei-Long Wang Yi Wang Wen-Huai Zhang Heng Zheng Yu-Cong Kou Xiao-Mei Wu Shi-Zhang Shao Tian 《Environmental science and pollution research international》2021,28(32):43402-43416
Environmental Science and Pollution Research - Two sets of hybrid constructed wetlands (HCWs) with the first-stage aeration were used to treat actual domestic sewage in this paper, where the... 相似文献
778.
Lyu Yucai Yang Tao Liu Herong Qi Zheng Li Ping Shi Ziyao Xiang Zhen Gong Dachun Li Ning Zhang Yaoping 《Environmental science and pollution research international》2021,28(16):19866-19877
Environmental Science and Pollution Research - Chromium (Cr) is one of the most widely used heavy metals in industrial processes, resulting in water and soil pollution that seriously threaten... 相似文献
779.
汉江流域秦巴山区中药材资源优势与持续发展 总被引:1,自引:0,他引:1
郑远昌 《长江流域资源与环境》1997,6(4):329-333
汉江流域秦巴山区生态环境复杂,生物多样性突出,中药材资源丰富,具有很大优势,主要表现在:种类多;产量大;多名优特种类。中药材生产对山区经济发展起重要作用。中药材生产持 拟采取下列措施或途径;建设专门化生产基地;进行综合性经营;加强对野生资源保护性利用;加强科研工作。 相似文献
780.
自然资源代际转移模型研究 总被引:4,自引:2,他引:2
代际均衡发展是可持续发展的核心内容之一,而代际均衡的实现在目前情况下有赖于代际主动财富转移改策实施。政府的宏观调控是实施这一政策的有力手段。具体的措施可开征“资源代际补偿税”以建立专项基金制度 相似文献