Novel fertilizers have emerged as viable alternatives to conventional fertilizers, effectively enhancing agricultural productivity-especially in paddy soils. However, their application may introduce emerging contaminants including antibiotic resistance genes (ARGs). In this study, we systematically evaluated the impacts of three types of fertilizers-conventional chemical (CC), organic-inorganic composite (OI), and slow-and controlled-release (SC) fertilizers-on soil fertility, microbial communities, and ARGs in paddy fields of Xiong'an New Area, China. SC had the greatest effect on soil fertility, increasing nitrogen, phosphorus, and organic matter levels by 5.25 %-23.15 %. The abundance of ARGs varied with different treatments. Higher levels of ARGs, at 0.28 copies per 16S rRNA gene copy, were found in the surface soils of the CC and OI treatments, whereas lower levels, at 0.26 copies per 16S rRNA gene copy, were observed in the rhizosphere soil of the OI treatment. OI showed the highest abundance of top five subclasses ARGs in rhizosphere soil, indicating enhanced risk of ARG generation, especially in the rhizosphere. Additionally, OI resulted in higher microbial diversities, with key genera including Streptomyces (4.3 %-5.2 %), Bradyrhizobium (2.4 %-2.9 %), and Sphingomonas (2.1 %-2.7 %) showing positive correlattions with most ARGs. Redundancy analysis, network plots, and Mantel test indicated that nutrients explained 58.45 % of the variation in ARGs followed by soil properties. This study demonstrates that SC fertilizers represent a promising alternative for sustainable agriculture, effectively enhancing soil fertility while minimizing ARG dissemination risks. Our findings underscore the importance of implementing stringent contaminant management protocols when substituting conventional fertilizers with novel alternatives.

Potential risk identification of agricultural nonpoint source pollution (ANPSP) is essential for pollution control and sustainable agriculture. Herein, we propose a novel method for potential risk identification of ANPSP via a comprehensive analysis of risk sources and sink factors. A potential risk assessment index system (PRAIS) was established. The proposed method was used to systematically evaluate the potential risk level of ANPSP of Yichang City, Hubei Province. The potential risk of ANPSP in Yichang City was 18.86%. High-risk areas account for 4.95% and have characteristics such as high nitrogen and phosphorus application rates, large soil erosion factors, and low vegetation coverage. Compared with the identification results of the Diffuse Pollution estimation with the Remote Sensing (DPeRS) model, the area difference of the same risk level calculated by the PRAIS was reduced by 33.9% on average. This indicates that PRAIS has the same level of accuracy as the DPeRS model in identifying potential risks of ANPSP. Thus, a rapid and efficient identification system of potential risks of regional ANPSP was achieved.

Urban non-point source (NPS) pollution has gradually become one of the important factors affecting the urban water environment. The quantitative evaluation of urban NPS pollution is the priority to identify key control area of urban NPS pollution. Current model applied in China is mainly focused on small-scale area, large-scale spatial continuous simulation is lacking. In this study A spatial continuous evaluation method coupled with high-resolution remote sensing data has been established and the method was applied to Tongzhou, China. With the spatial distribution of land-use type and built-up area which were been obtained by remote sensing technology, the accumulative and wash-off load of urban NPS nitrogen and phosphorus were estimated for the prominent problems of nitrogen and phosphorus nutrient pollution in the rivers in the study area. The main sources of urban NPS Nitrogen and phosphorus pollution are roof and road rainfall runoff respectively. Compared to other urban NPS pollution models, the method developed in this study can quickly realize spatial visualization assessment of urban NPS pollution and provide a means to estimate urban NPS loads in entire city or urban agglomeration, it is applicable for common urban NPS pollutants and also has advantages in areas without data.

Storage temperature is a key factor in determining gas emissions from slurry storage. The reactive nitrogen related gas (NH3, N2O, and NO) emission characteristics and resulting mechanisms from digested pig slurry stored under different temperatures of 5 (A5), 15 (B15), 25 (C25), and 35 degrees C (D35) were investigated in this study. Results showed that the temperature increase from 15 to 25 degrees C was crucial for the changes in the total chemical characteristics of slurry, the increase of gas emissions, and the nitrifiers and denitrifiers accumulation in the slurry. Chemical oxygen demand, total nitrogen (TN), and total ammonia nitrogen content of the slurry decreased while pH increased significantly during storage under C25 and D35, while no obvious changes can be found under A5 and B15. NH3, N2O, and NO emissions increased by 284%, 451%, and 454%, respectively, when the storage temperature increased from 15 to 25 degrees C. The highest emissions of NH3, N2O, and NO were observed in D35, with the emission factor being 42.3% +/- 9.0%, 2.26% +/- 0.96%, and 0.11% +/- 0.03% of initial TN, respectively; while the lowest emission factor was 4.2% +/- 0.2%, 0.04% +/- 0.01%, and 0.0003% +/- 0.0001% for NH3, N2O, and NO in A5, respectively. The high temperature caused the increased abundance of Nitrosomonas, leading to the high N2O emission in D35. Vulcanibacillus and Thauera were the dominant denitrifiers in the microbial communities, and their increased abundance was another possible explanation for increased N2O emission on C25 and D35. Therefore, regulating slurry temperature to lower than 15 degrees C can effectively limit the NH3 and N2O emissions, and thus contributed to the air pollution reduction and global warming control. Meanwhile, compared with the cool temperature conditions, extra mitigation options were suggested to be applied to control the gases emissions when slurry was stored under hot conditions such as in summer.

在综合分析农业面源污染风险源汇因子的基础上,筛选出影响海河流域农业面源污染的8个主要因子(年降水量、溶解态面源污染物入河系数、吸附态面源污染物入河系数、年植被覆盖度、坡度、土壤可侵蚀性因子、农田氮表观平衡量和农田磷表观平衡量),建立了农业面源污染潜在风险识别指标体系,采用多因子综合分析法对海河流域农业面源污染潜在风险等级进行评价,并与DPeRS模型风险识别结果进行偏差分析.结果 表明,海河流域有61.91％的区域存在农业面源污染潜在风险,集中分布在流域的中部和南部地区,高风险区主要分布在北京市东南部、天津市中部、流域山东段东北部和河南段南部等区域;与DPeRS模型识别结果对比验证,显示同一风险等级面积相差不超过12％,且高风险级别面积相差仅为0.12％,97.17％以上的区域均为偏差小或无偏差,表明该识别方法具有与DPeRS模型法同等水平的农业面源污染潜在风险识别精准度,可实现区域农业面源污染潜在风险的快速、高效识别.

Broiler and layer productions are important ammonia (NH3) emission sources in the livestock industry. Here, we present the first meta-analysis and integrated assessment of NH3 emissions and mitigation potentials for typical broiler litter manure management system (MMS) and layer manure belt MMS based on data from 96 studies. A total of 10 integrated NH3 emission factors (EFs) and the NH3 mitigation efficiencies (MEs) of 14 available options were provided. The estimated NH3 emissions from the baseline scenarios of the broiler litter MMS and the layer manure belt MMS were 84.1 +/- 5.9 kg AU(-1) yr(-1) and 53.5 +/- 15.8 kg AU(-1) yr(-1), respectively. The NH3 mitigation for the broiler litter MMS should be focused on the in-house stage, while the mitigation in the layer manure belt MMS should be focused on the outdoor and land application stages. The recommended NH3 mitigation options for the in-house stage, the outdoor stage and the land application stage were acid scrubber (-92.5%), compost biofilter (-71.9%) and changing the manure surface application to incorporation (-83.0%), respectively. The recommended mitigation combinations of low crude protein (LCP) diet, acid scrubber, compost biofilter and manure incorporation achieved the highest NH3 mitigation efficiency from both broiler litter MMS and layer manure belt MMS, by 89.3% and 84.8%, respectively. The results of this study have important implications for developing sustainable poultry production systems from the viewpoint of NH3 mitigation. The environment issues such as the other reactive nitrogen emissions and the greenhouse gas (GHG) emissions should also be considered in the future. (C) 2019 Elsevier Ltd. All rights reserved.

Bioventing is an in-situ forced oxidative soil remediation technology,which combined soil vapor extraction (SVE) technology with biodegradation.It has broad application prospect for soil contamination caused by underground tank leakage due to its higher-performance,lower treatment cost and tail gas treatment cost,compared with SVE.In this paper,a sand-box experiment was conducted to simulate the bioventing technology for repairing diesel contaminated sandy soil.The main conclusions were as follows:The original equilibrium state and the sand adsorption of diesel was broken under the vacuum extraction from extraction well on the top of sand box;diesel contaminants in the soil (mainly volatile components) showed migration and diffusion in horizontal and vertical direction,and the vertical migration and diffusion was more obvious.Intermittent ventilation made the position of TPH high value area in sand box change continuously.

Beef cattle production systems are the largest contributors of greenhouse gas (GHG) and ammonia (NH3) emissions in the livestock industry. Here, we present the first meta-analysis and integrated assessment of gaseous emissions and mitigation potentials for a typical beef cattle feedlot system, including methane (CH4), nitrous oxide (N2O), and NH3 losses from enteric fermentation and manure management based on data from 104 studies. A total of 14 integrated emission factors (EF) and the mitigation efficiencies (ME) of 17 available options were provided. The estimated GHG and NH3 emissions from the baseline feedlot system were 2786 ± 108 kg carbon dioxide equivalents (CO2-eq) per animal unit (AU) per year and 49.1 ± 1.5 kg NH3 AU-1 year-1, respectively. Enteric CH4 fermentation and manure on the feedlot contributed 67.5% and 80.8% of the total system GHG and NH3 emissions, respectively. The highest ME values were found for lipid additives for enteric CH4 fermentation and urease inhibitor additives (UI) for NH3 emissions from manure on the feedlot, being -14.9% ( p < 0.05) and -59.5% ( p < 0.001), respectively. The recommended mitigation combinations of a low-crude-protein (CP) diet and a UI additive for manure on the feedlot could reduce the GHG of the system by 4.9% and NH3 by 50.9%. The results of this study have important implications for developing sustainable beef cattle feedlot systems from the viewpoint of GHG and NH3 mitigation.

畜禽养殖的氨气(NH3)和颗粒物(particulate matter,PM)排放已成为危害人畜健康,并可能造成环境风险的重大问题.该文选择北京郊区一典型规模化蛋鸡养殖舍,对典型冬季条件下蛋鸡舍的NH3和PM排放进行了连续8 d的监测;并根据二氧化碳平衡原理,对NH3及PM的排放通量进行了估算.研究结果表明,蛋鸡舍出风口处NH3平均质量浓度为(4.58±3.29)mg/m3,每只鸡NH3排放通量为(32.2±12.5)mg/d.蛋鸡舍出风口处PM2.5、PM10和总悬浮颗粒物(total suspended particulates,TSP)质量浓度为(0.13±0.06)、(0.81±0.16)、(3.28±1.32)mg/m3,每只鸡PM2.5、PM10和TSP排放通量分别为(0.7±0.4)、(6.3±1.4)、(27.6±12.5)mg/d.氨气以及PM的排放均随着舍内1次/2 d的机械清粪频率呈现2 d的周期变化趋势.除清粪作业、鸡群日间活动等影响外,舍内PM2.5浓度一定程度上受舍外环境本底值影响.舍内PM2.5与PM10的比例在10.4％～20.4％之间.舍内PM2.5颗粒上所含的K+、Mg2+含量均显著高于舍外环境本底PM2.5(P<0.05).同时舍内及舍外PM2.5颗粒上解析出来的阳离子所带的电荷量均高于阴离子.研究结果可为畜禽养殖NH3和PM排放清单的编制提供基础参数;同时对畜禽舍PM的组分研究,可为后续开展二次无机气溶胶形成机理以及颗粒物源解析的研究提供支撑.

Livestock houses are an important ammonia ( NH3 ) emission source, understanding the ammonia e-mission characteristics and mitigation technologies is of high importance to the livestock healthy production to-gether with achieving high environmental benefits.The NH3 emission characteristics of three major livestock houses, including pig, poultry and cattle houses were reviewed in this paper, and the key influencing factors for NH3 emission in each livestock house also were discussed and compared.The commonly used in-house NH3 mitigation technologies were summarized in this review.The mitigation technologies included the feed optimiza-tion on source, using the manure additive after manure being excreted, and the air cleaning infrastructures and the exhaust air filtering devices, to build a comprehensive mitigation system for livestock house NH3 emission. The result of this study was of high importance for understanding the NH3 emission characteristics from live-stock houses, and also for a reasonable choice of mitigation technologies for livestock house NH3 emission.

宁夏黄灌区是我国商品粮生产基地之一,农业高强度和化肥高投入对灌区水环境和黄河水安全造成了严重威胁.农田退水中氮素迁移流失的网室土柱模拟实验表明:①每次施肥1～2 d后(穗肥是1周后),田面水中全氮量均出现峰值,不断下降后逐渐趋于稳定,全氮量随时间的变化符合对数衰减规律;②3次施肥后,种植水稻的土柱各土层渗漏水中的全氮量高于未种植水稻的土柱,水稻根系的发育,一定程度上促进了氮素向下迁移,加剧了氮素流失的风险,水稻收获前控制氮的渗漏损失尤为重要.

The aim of study is to get main pollutants and spatial distribution in the upstream rivers in Miyun Reservoir, Beijing.210water samples were collected from fourteen river sections in every month in 2012to study spatial distribution of nitrogen and phosphorus.The results showed the same orders of the content of TN,TP,NO3-N and NH3-N were Chao RiverQingshui RiverBai River.The average measured concentration of TN,TP,NO3-N and NH3-N of Chao River were 4.63,0.024,4.41and 0.17mg/L,separately.The spatial distribution of concentration of TN,NO3-N,NH3-N were gradually decreased from upstream to the sections near the reservoir in Chao River,and maybe associated with the water conservancy project,the river self-purification and dilution.According to the national environmental water quality standards,the concentration of NH3-N,TP of three rivers were classified to level II,but TN exceed the quality standard of level V,also,the concentration of TN of thirteen river sections exceeded the standard of level V(2.0mg/L).Single contamination index method applied to evaluate water quality on the annual average TN,TP and NH3-N,it showed that TP and NH3-N classified into no pollution,but TN being heavy pollution indicating that the Nitrogen pollution cannot be ignored in upstream rivers to Miyun reservoir.

Groundwater samples were collected from intensive agricultural regions of 13 districts in Beijing from 2005 to 2012 to determine the status of nitrate nitrogen(N)contamination in groundwater. The results indicated that the mean concentration of nitrate-N of all samples analysed in Beijing was 6.34 mg NO-3-N·L-1 . There were 19.36% of the samples exceeding 10 mg·L-1 , and 6.73% of the samples exceeding 20 mg·L-1 . The annual average concentration of nitrate-N varied from 5.85 mg·L-1 to 6.93 mg·L-1 , which met the category III national water quality standard. Nitrate leaching was enhanced by rainfall and higher concentrations of nitrate-N in groundwater were observed after rainy seasons. The nitrate-N concentration in groundwater was affected by the land use system in the following order:vegetable fieldarable croppingother land usesorchards, with the mean nitrate-N concentration being 7.66 mg·L-1 , 6.15 mg·L-1 , 5.58 mg·L-1 and 4.97 mg·L-1 , respectively. The nitrate-N concentration in groundwater decreased with increasing groundwater depth, and the average concentration within 30 m was 12.71 mg·L-1 , exceeding the WHO drinking water guideline.

Bioventing is an in situ forced oxidative soil remediation technology which combined soil vapor extraction with biodegradation. It has broad application prospects of soil contamination caused by underground storage tank leakage. Orthogonal experiment as a high efficiency, rapid and economical experimental design method has been widely used in many research. In order to enhance bioventing and shorten the cycle of pollution control,it is necessary to study the mechanism of the interaction among the different factors to quantify the interaction and accelerate the degradation rate. In this study, five factors (initial diesel concentration, venting mode, pore volume number during soil venting, soil moisture content and the ratio of carbon, nitrogen and phosphate) which influence bioventing was chosen to conduct orthogonal experiment of the remediation of diesel contaminated soil by enhancing bioventing. The results show that: 1)Initial diesel concentration and soil moisture content have main effects on the remediation of diesel contaminated soil by bioventing, then the ratio of carbon, nitrogen and phosphate and pore volume number during soil venting. Venting mode has the weakest effect. 2)When 40mg oil/g soil of diesel concentration, air injecting from the bottom of column, 4 vk·d-1 of the pore volume number during soil venting, 100:20:1 of the ratio of carbon, nitrogen and phosphate and soil water content for 20% of the maximum of soil water holding capacity, that would reach a larger removal rate.

Bioventing is an in situ forced oxidative soil remediation technology which combined soil vapor extraction with biodegradation. It has broad application prospects of soil contamination caused by underground storage tank leakage. In this paper, soil column experiment which was used to simulate diesel contamination was conducted. The law of balance distribution of residual TPH (Total Petroleum Hydrocarbon) concentration at different time and the changes of diesel amount in soil at different depths, together with total diesel amount of the entire column were analyzed. The results showed that: (1) The initial soil moisture content affects the distribution and changes of TPH content during the natural attenuation and enhancing bioventing. (2) Gravity diffusion and migration was the main causes for the changes of TPH content of entire column in the early days of natural attenuation, within one month. Approximately 2 months' venting later, extraction was prominent to maintain stable changes of the diesel concentration in the upper of soil column.

Bioventing is an in situ forced oxidative soil remediation technology which combines soil vapor extraction with biodegradation.It has broad application prospects of soil contamination caused by underground storage tank leakage.In this paper,soil column experiment,which was used to simulate diesel contamination,was conducted.The law of balance distribution of residual TPH at different times and the change of diesel quantity in soil at different depths,together with total diesel quantity of the whole column were analyzed.The results showed that:(1) The profile distribution difference of residual TPH was influenced largerly by the initial loading conditions of soil column.(2) The diesel in soil was removed mainly by volatilization and biological degradation for the column which the balance distribution curves of residual TPH was bimodal.(3) Volatilization was mainly influenced by pore volume number during soil venting and soil moisture content,and gravity was mainly influenced by initial diesel concentration,soil moisture content and the ratio of carbon,nitrogen and phosphate.In addition to venting mode,the other factors affect the biodegradation.(4) For the soil column 8 and 11,which the initial diesel concentration were higher and the soil moisture content were both less,the biodegradation was the most significant and the removal effect of diesel in soil column was the best.The results could provide a theoretical basis for the enhancement of bioventing process.

Taking 0# diesel oil as the sole carbon source,four diesel-degrading strain(B-1,B-2,B-3 and B-4)are selected from the sand box of diesel contaminated soil.The results of morphological observation and identification of molecular biology show that these strains belong to Microbacterium sp.,Brevundimonas sp.,Pseudomonas sp.,Pseudomonas sp.,respectively.And strain B-3 is a new diesel-degrading strain first found in Kashmir orchard soil in 2005.In addition,strain B-3 and B-4 have preferentially accessed to the logarithmic growth phase than the other two strains through comparing the growth curve of each strain.It is significant for accelerating the biodegradation of diesel oil.

Bioremediation technology has great application prospects for soil contamination caused by diesel.The effects of environmental factors(temperature and pH value) on the growth status of indigenous diesel-degrading strains,which were enriched,separated,screened from the sandbox device of simulating diesel-contaminated soil remediation,were studied.The degradation performances were also primarily evaluated in this paper.The results showed that the strains could grow within 10～35℃,and the best cultural temperature of strain B-1,B-2,B-3 and B-4 was 30℃,30℃,25℃ and 25℃,respectively.The optimum pH value of the strains was 7.0～7.5.The degradation rate of strain B-3 was obviously higher than that of strain B-4 for different initial volume fraction of diesel.Especially,when the initial volume fraction of diesel was 1.5%,the degradability was the strongest and the degradation rate of diesel for strain B-3 was 60.98%,increased by 23.8% than that for strain B-4.And the degradability of strain B-4 was gradually weakened with the increasing of initial volume fraction of diesel.Studying these diesel-degrading strains in depth could lay a theoretical foundation for enhancing the bioremediation effect of diesel contaminated soil.