剩余污泥水解酸化液中营养元素与有机质的回收

为回收剩余污泥水解酸化液中的营养元素与有机质,构建了白云石-水解酸化液钙镁溶出体系,获得富含钙镁的溶出液,控制溶出液反应pH和反应时间进行第1阶段回收,以回收后的上清液进一步作为钙镁源从水解酸化液中进行第2阶段回收。结果表明,钙镁溶出的适宜条件为酸化pH 4.0~4.5、白云石颗粒50~80目、固液比3∶100(每100mL水解酸化液中投加3g筛分后白云石)、溶出时间10h;第1阶段回收适宜的反应pH为8.5,氮(以氨氮计)回收率、磷(以可溶性正磷酸盐(以P计)计)回收率分别为10.24%和95.89%;第2阶段回收适宜的镁磷摩尔比为0.60、反应pH为9.0,此时氮、磷回收率分别为14.60%和83.91%;傅立叶红外变换(FTIR)和电感耦合等离子直读光谱(ICP)分析表明,回收产物主要由无机养分和有机质组成,重金属含量极少。利用白云石提供钙镁源能经济有效地回收剩余污泥水解酸化液中的氮、磷等营养元素,同时回收有机质,回收产物品质符合《有机-无机复混肥料》(GB 18877—2009)中Ⅰ型肥料要求。     

Static yields and quality issues: Is the agri-environment program the primary driver?

The Finnish agri-environmental program (AEP) has been in operation for 20 years with >90 % farmer commitment. This study aimed to establish whether reduced nitrogen (N) and phosphorus (P) use has impacted spring cereal yields and quality based on comprehensive follow-up studies and long-term experiments. We found that the gap between genetic yield potential and attained yield has increased after the AEP was imposed. However, many contemporary changes in agricultural practices, driven by changes in prices and farm subsidies, also including the AEP, were likely reasons, together with reduced N, but not phosphorus use. Such overall changes in crop management coincided with stagnation or decline in yields and adverse changes in quality, but yield-removed N increased and residual N decreased. Further studies are needed to assess whether all the changes are environmentally, economically, and socially sustainable, and acceptable, in the long run. The concept of sustainable intensification is worth considering as a means to develop northern European agricultural systems to combine environmental benefits with productivity.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0637-9) contains supplementary material, which is available to authorized users.     

利用巨大芽孢杆菌制备高硫煤矸石肥料

高硫煤矸石的大量堆积对环境造成了严重污染,为了开发利用高硫煤矸石,对巨大芽孢杆菌处理高硫煤矸石生产煤矸石肥料进行了研究,包括煤矸石的粒径、体系p H、温度、接菌量、培养时间、振荡等因素条件对制备煤矸石肥料的影响,得到制备煤矸石肥料的最佳条件。研究表明,当煤矸石的粒径为60目、体系p H 7.0~8.0、接菌量为2.5×1014~5.0×1014cfu/g、30℃下培养5 d时煤矸石中的碱解氮、有效磷和速效钾的含量分别比原样提高了26.84倍、65.71倍和10.55倍;有效硫、有效钙和有效硅的含量分别比原煤矸石中提高2.70倍、1.27倍和1.07倍。     

Sustaining food self-sufficiency of a nation: The case of Sri Lankan rice production and related water and fertilizer demands

Rising human demand and climatic variability have created greater uncertainty regarding global food trade and its effects on the food security of nations. To reduce reliance on imported food, many countries have focused on increasing their domestic food production in recent years. With clear goals for the complete self-sufficiency of rice production, Sri Lanka provides an ideal case study for examining the projected growth in domestic rice supply, how this compares to future national demand, and what the associated impacts from water and fertilizer demands may be. Using national rice statistics and estimates of intensification, this study finds that improvements in rice production can feed 25.3 million Sri Lankans (compared to a projected population of 23.8 million people) by 2050. However, to achieve this growth, consumptive water use and nitrogen fertilizer application may need to increase by as much as 69 and 23 %, respectively. This assessment demonstrates that targets for maintaining self-sufficiency should better incorporate avenues for improving resource use efficiency.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0720-2) contains supplementary material, which is available to authorized users.     

秦巴山区水稻油菜配方施肥效益分析

为了解陕南秦巴山区主要农作物水稻、油菜测土配方施肥实施效果,更好地指导农户科学合理施肥。依据2009~2013年连续5 a测土配方施肥试验中主要农作物水稻、油菜3种不同施肥处理(农民习惯施肥、推荐施肥和不施肥处理)的326个试验数据,同时结合连续2 a调查数据,对陕南秦巴山区主要农作物施肥经济效益评价。结果显示,与农民习惯施肥相比,水稻施肥量为:氮(N)159±32 kg/hm~2,磷(P2O5)79±20 kg/hm~2,钾(K2O)86±26 kg/hm~2;油菜:氮(N)154±25 kg/hm~2,磷(P2O5)77±13 kg/hm~2,钾(K2O)65±21 kg/hm~2条件下作物分别增产703、341 kg/hm~2,增产率分别为8.3%和14.9%,纯收益增加0.12万元/hm~2和0.10万元/hm~2。肥料贡献率分别提高了5.2、7.1个百分点;农学效率每kg分别提高了0.5、0.6 kg。农户习惯施肥中作物产量、纯收益、肥料贡献率并未随肥料投入量的增大而增产增收。     

光电技术在大气氮氧化物检测中的应用

介绍了大气中氮氧化物的组成,综述了激光诱导荧光法、光纤传感法、激光雷达探测法和化学发光法测定大气中氮氧化物的原理和特点,指出光电技术已在大气氮氧化物检测中得到了广泛的应用,并具有良好的发展前景。     

Precipitation as the Primary Driver of Variability in River Nitrogen Loads in the Midwest United States

Nitrogen (N) losses from agricultural lands in the Midwest United States are contributing to the expansion of the hypoxic zone in the Gulf of Mexico. This study evaluated the importance of inter‐annual variability in precipitation, land cover, and N fertilizer use on NO₃ + NO₂‐N loads in seven United States Midwestern Rivers using the backward stepwise regression analysis. At the annual scale, fluctuations in the current and previous years’ precipitations explained much of the variation in streamflow, baseflow, and N‐load. Previous years precipitation effects were associated with fillable soil porosity. In some years, higher residual soil N from previous dry years also contributed to an increase in N‐load. Area under soybean production (SOY), a surrogate for replacement of prairies and small grains was generally not a significant explanatory variable. Fertilizer use from 1987 to 2012 was also not a significant explanatory variable in the annual analysis. Precipitation in both the current and previous months and previous year were important in explaining variation in monthly streamflow, baseflow, and N‐load. SOY was significant in one or two months from June to August, but had a higher p‐value than precipitation. We conclude recent increases in river N‐loads are primarily due to wet climate and minimally due to the changes in land cover or N fertilizer use. Under current cropping systems and agronomic N application rates, tile water remediation will be necessary to reduce river N‐loads.     

A^2/O-MBR组合工艺运行优化与氮磷深度控制的分析

为了遏制水环境不断恶化的趋势,应加强对氮、磷超标的治理工作,促进水生态环境平衡发展。本文采用A^2/O-MBR作为主体工艺,后续辅以化学除磷和以深床滤池为反硝化单元的组合工艺,确保最终出水满足天津市《城镇污水处理厂污染物排放标准》(DB12/599-2015)A标准排放要求。     

浅析成都市机动车保有量的增加对大气污染物中二氧化氮浓度的影响

本文利用成都市城区近4年的环境空气二氧化氮浓度资料,结合成都市机动车保有量,分析了成都市机动车保有量的增加对空气中二氧化氮浓度的影响。分析表明,成都市机动车保有量的增加对空气中二氧化氮浓度有明显影响,尤以交通干道附近最为显著,二氧化氮浓度较非交通干线分别偏高12.0%～47.8%,成都市采取的高污染车限行等措施对二氧化氮浓度的控制起了重要作用。     

Biomonitoring of traffic-related nitrogen oxides in the Maurienne valley (Savoie, France), using purple moor grass growth parameters and leaf N/N ratio

Effects of traffic-related nitrogenous emissions on purple moor grass (Molinia caerulea (L.) Moench) transplants, used here as a new biomonitoring species, were assessed along 500 m long transects orthogonal to roads located in two open areas in the Maurienne valley (French Alps). Leaves were sampled during summer 2004 and 2005 for total N-content and ¹⁵N-abundance determination while nitrogen oxides (NO and NO₂) concentrations were determined using passive diffusion samplers. A significant and negative correlation was observed between plant total N-content, and ¹⁵N-abundance and the logarithm of the distance to the road axis. The strongest decreases in plant N parameters were observed between 15 and 100 m from road axis. They were equivalent to background levels at a distance of about 800 m from the roads. In addition, motor vehicle pollution significantly affected vegetation at road edge, as was established from the relationship between leaf ¹⁵N-abundance, total N-content and road traffic densities.