晋江西溪流域茶园降雨径流产污特征

在野外模拟降雨条件下,开展了晋江西溪流域茶园和裸地的径流产沙及氮磷养分流失过程对比实验,研究结果表明,在相同降雨强度下,3种下垫面径流和产沙量顺序均为:裸地＞2年茶园＞4年茶园,径流量与产沙量之间呈显著正相关.对地表径流水相而言,2年茶园、4年茶园和裸地的TN流失量分别为:461.29、129.38和107.86 mg/m2;NO3-N流失量分别为:286.42、98.58和103.00 mg/m2,均占TN流失量的60％以上;NH4-N流失量分别为:48.67、16.19和4.42 mg/m2;Tp流失量分别为:34.71、16.47和23.88 mg/m2.对径流泥沙相而言,2年茶园、4年茶园和裸地的TN流失量分别为:379.28、44.81和747.16 mg/m2,占流失总量的比重在25.72％～87.93％之间;TP流失量分别为:27.94、4.17和58.85 mg/m2,占流失总量的比重在53.42％ ～68.36％之间.茶园的N、P主要随径流流失,而裸地以泥沙迁移为主.这说明茶叶种植具有一定的水土保持效应,且种植年限较长的茶园可显著减少随径流泥沙进入水体中的N、P元素.     

沛沿河流域农田地表径流氮流失的模拟研究

在室内人工模拟降雨条件下,选择沛沿河流域最具代表性的3种土地利用类型,研究暴雨过程中农田地表径流氮的流失规律。结果表明,在暴雨条件下,3种土地利用类型的地表径流量大小顺序为水稻田林地果地;地表径流氮流失量随土地利用类型表现出明显差异,暴雨条件下3种土地利用类型的地表径流水相TN流失量大小顺序为果地林地水稻田,地表径流水相颗粒态氮(PN)占水相TN的比例在67%以上,地表径流沉积物相TN流失量大小顺序为林地水稻田果地,地表径流氮流失均以水相为主;3种土地利用类型的累积地表径流量与累积氮流失量的相关系数都在0.99以上。     

施肥方式对东北玉米种植区氮磷流失的影响

研究不同施肥方式下东北玉米单作种植体系氮磷流失规律,可为该地区农田面源污染防控及生态保护提供技术参考。试验设置农民习惯处理、优化施肥处理、秸秆还田处理和有机肥化肥混施处理,采用自然降雨条件室外模拟方法,分析不同施肥处理对东北玉米种植区径流淋溶氮磷流失的影响。结果表明,在东北地区玉米单作模式下,多雨年份优化施肥处理与农民习惯处理相比可降低15.8%的总氮流失负荷,降低7.3%的总磷流失负荷;秸秆还田处理可明显降低22.9%的总氮流失负荷及15.1%的总磷流失负荷;有机肥化肥混施处理降低总氮流失负荷13.6%,但增加总磷流失负荷13.9%;氮磷流失负荷以泥沙流失为主,淋溶流失其次。结合作物产量,在多雨年份,优化施肥处理和秸秆还田施肥处理是防控东北玉米区农田面源污染和保证作物产量的理想施肥方式。     

渗排植被浅沟应用于处置路面径流案例分析

针对非点源径流污染问题,在对渗排植被浅沟的构造、场地布置原则、设计流量、水力计算及主要参数等分析的基础上,以廊坊市大皮营渠沿线雨洪控制利用工程中新型植被浅沟处理路面径流为例,从水质净化及径流削减两方面考察了浅沟的运行效果。结果表明,渗排浅沟对小降雨事件能发挥较好的径流削减效果,其径流削减百分比随进水流量的增加减小。相比于传统传输型植被浅沟,径流中SS、TP得到了有效去除,COD、NH+4-N则由于其溶解性较强而去除率提升幅度不高。     

不同类型透水砖对雨水径流水量的控制效果

透水铺装是目前海绵城市建设中应用较广泛的技术措施之一,对雨水径流的促渗减排发挥着重要作用。选择2种不同类型透水砖为研究对象,采用人工模拟降雨实验方法,研究了降雨重现期分别为1、3、5、10 a条件下,2种不同类型透水砖对雨水径流总量控制、峰值削减和峰值延迟等方面的控制效果。结果表明：在降雨重现期小于10 a的条件下,构造透水砖和普通透水砖的场次降雨总量控制率平均值均超过95%;峰值流量均随着重现期的增加而增大,构造透水砖的峰值削减效果优于普通透水砖,平均峰值削减率提高了8.6%;构造透水砖和普通透水砖的出流延迟时间平均值分别为11.3 min和13.8 min,平均峰值延迟时间分别为6.3 min和16.3 min。构造透水砖对径流总量、峰值流量的控制效果要优于普通透水砖,因此,在透水铺装应用中,应结合项目设计目标和当地的水文地质条件,宜优先考虑采用构造透水砖铺装方式。     

降雨入渗与地表径流污染减量模拟试验研究

针对造成水体污染的城市降雨地表径流问题,建立模拟降雨系统,选用聚合物与功能材料,改良土壤结构,提高土壤对雨水的渗透性,削减地表径流及径流携带污染物对纳污水体的污染.结果表明,复合施用PAM与沸石使降雨径流过流体土壤结构被改良,对降雨径流的削减作用明显,对土壤的降水渗透有显著的促进.数据表明,沸石与PAM配施对削减降雨地表径流与提高降雨土壤入渗的效果有协同作用.在36、72和108 mm/h不同降雨强度下,处理土壤水的入渗较对照分别提高了35%～76%、32%～66%和18%～47%,降雨后土壤的含水量较对照可提高1～5倍.     

降雨入渗与地表径流污染减量模拟试验研究

针对造成水体污染的城市降雨地表径流问题,建立模拟降雨系统,选用聚合物与功能材料,改良土壤结构,提高土壤对雨水的渗透性,削减地表径流及径流携带污染物对纳污水体的污染.结果表明,复合施用PAM与沸石使降雨径流过流体土壤结构被改良,对降雨径流的削减作用明显,对土壤的降水渗透有显著的促进.数据表明,沸石与PAM配施对削减降雨地表径流与提高降雨土壤入渗的效果有协同作用.在36、72和108 mm/h不同降雨强度下,处理土壤水的入渗较对照分别提高了35%～76%、32%～66%和18%～47%,降雨后土壤的含水量较对照可提高1～5倍.     

基于SWMM模型的万州龙宝河片区径流污染控制研究

为评价重庆万州龙宝河片区海绵城市改造的径流污染控制效果，运用SWMM模型模拟该片区的径流过程，研究不同重现期下绿色屋顶、透水铺装、生物滞留带等低影响开发(LID)设施对污染物的控制效果。结果表明：当重现期为1～50 a时，LID设施对悬浮固体(SS)、化学需氧量(COD)、总磷(TP)、总氮(TN)的总量削减率分别可达47%～72%、56%～70%、48%～64%、43%～66%;对上述污染物峰值浓度的削减率分别为31.31%～41.05%、25.12%～38.93%、22.50%～31.38%、13.39%～21.76%,并能延迟峰现时间2～11 min。由此可见，海绵城市改造能够有效缓解径流污染，但随着重现期增加，控制效果会变差，说明海绵城市更适用于低降雨强度的径流污染控制。     

城市绿地土壤渗透性改良对雨水径流污染的削减效果及去除规律

为考察土壤渗透性改良后的径流污染削减效果和去除规律,以上海浦东某已建居住社区绿地土壤特性为样本,采用中粗砂和沸石进行渗透性改良并开展径流污染削减实验。结果表明:改良后土壤渗透性能明显提高,具有较好的截留和净化污染物作用;通过土壤成分、污染负荷、流量负荷和渗滤深度对COD、TN、TP和NH_4~+-N去除效果的影响分析,提出了不同径流污染特征下可采用不同的土壤渗透性改良方案,实现对特征污染物更有效的削减效果。研究结果可为改良城市居住社区绿地土壤渗透性,缓解初期雨水径流污染提供参考和借鉴。     

生物滞留池对地表径流中常规污染物及全氟化合物的去除效果

生物滞留系统是实现城市地表径流水量调控和水质净化的新型绿色生态系统,但其对全氟化合物的去除效能尚不清楚。本文构建了将传统填料与2~4 mm沸石(体积占比10%)或2~4 mm的改良煤质颗粒活性炭(体积占比10%)混合的2种柱形生物滞留系统,通过动态实验探究了此系统对地表径流中常规污染物和全氟化合物去除效果,分析了系统近1 a的运行效果。结果表明,生物滞留系统的水量削减率随运行时间的增长呈现下降的趋势,平均削减率为(29.8±8.2)%。改良煤质颗粒活性炭生物滞留池对COD、TN、TP、TOC、$ {\mathrm{N}\mathrm{H}}_{4}^{+} $-N的平均去除率分别为67.49%、84.78%、76.43%、80.28%、65.43%,优于以沸石为填料的滞留池。6种目标全氟化合物PFPeA、PFHxA、PFHpA、PFOA、PFOS、PFNA的去除率保持在80%以上。滞留池内污染物空间分布特征表明,PFBA主要集中于种植层,而PFPeA、PFHxA、PFHpA、PFOA、PFOS、PFNA则更集中于填料层。     

小花南芥与玉米间作对Pb化学形态及富集特征的影响

间作植物根与根之间的相互作用影响根际土壤理化性质。目前关于超富集植物与作物间作根际土壤pH是否引起Pb赋存形态的变化,不同赋存形态与超富集植物和作物富集Pb的差异机理尚不清楚。设置不同Pb处理浓度,小花南芥和玉米间作、单作为对照的土培实验。随着Pb处理浓度增加,间作小花南芥生物量显著增加,范围为19.00%~181.08%,Pb富集系数为2.78,显著增加74.02%,转运系数为1.46,变化不显著,其中Pb含量显著增加25%。Pb赋存形态主要以难溶态果酸盐、蛋白质和磷酸盐结合态存在,约占总量的50%,间作显著降低小花南芥根际土壤溶液、根和茎叶中的pH;间作玉米生物量随着Pb处理浓度先显著增加后降低,增加范围为18.59%~49.48%,Pb富集系数平均为0.53,显著降低34.57%,转运系数平均为0.56,显著降低12.51%,Pb赋存形态以草酸盐结合态存在,约占30%,间作显著增加玉米根际土壤溶液、根和茎叶中的pH。揭示间作改变2种植物根际土壤溶液、根和茎叶中pH,从而引起Pb化学形态不同,这是导致超富集植物小花南芥吸收富集Pb,降低玉米体内Pb的主要原因。     

Nitrate in waters from sewage-sludge amended lysimeters

Nitrate nitrogen was measured in runoff and tile-drainage during two years of operation of instrumented, large-scale lysimeters planted to corn (Zea mays L.) and amended with sewage sludge which was applied at rates supplying total N amounting to 2292 kg ha(-) in 1972 and 3286 kg ha(-1) in 1973. Other lysimeters were amended with inorganic fertiliser at the rate of 336 kg N ha(-1) year(-1). Annual losses in runoff and tile-drainage from sludge treatments were 0.9 and 5.1 and 371 and 663 kg NO(3)(-)-N ha(-1). Losses from lysimeters treated with inorganic fertiliser were 1.1 and 3.3 kg NO(3)(-)-N ha(-1) year(-1) in runoff and 31 and 79 kg NO(3)(-)-N ha(-1) year(-1) in tile-drainage. Given the nitrogen inputs accounted for in the study design, unaccounted for losses of 1800 to 2400 kg ha(-1) year(-1) were calculated for sludge and 277 kg ha(-1) year(-1) for inorganic fertiliser treatments. For one year there was a 300 kg ha(-1) increase in N in the lysimeters receiving inorganic fertiliser. Median NO(3)(-)-N concentrations ranged from 8.9 to 14.0 mg litre(-1) in runoff from sludge-treated lysimeters and 3.6 to 5.9 mg litre(-1) in runoff from lysimeters receiving inorganic fertiliser. In tile-drainage the median NO(3)(-)-N concentrations were 148 to 223 mg litre(-1) and 24 to 44 mg litre(-1) for sludge and inorganic fertiliser treatments, respectively. Highest runoff levels occurred in early summer storms, whereas highest tile-drainage concentrations occurred in late winter and early spring.     

Surface runoff and nitrogen (N) loss in a bamboo (Phyllostachys pubescens) forest under different fertilization regimes

Nitrogen (N) losses from agricultural fields have been extensively studied. In contrast, surface runoff and N losses have rarely been considered for bamboo forests that are widespread in regions such as southern China. The thriving of bamboo industries has led to increasing fertilizer use in bamboo forests. In this study, we evaluated surface runoff and N losses in runoff following different fertilization treatments under field conditions in a bamboo (Phyllostachys pubescens) forest in the catchment of Lake Taihu in Jiangsu, China. Under three different fertilization regimes, i.e., control, site-specific nutrient management (SSNM), and farmer's fertilization practice (FFP), the water runoff rate amounted to 356, 361, and 342 m³?ha^?1 and accounted for 1.91, 1.98, and 1.85 % of the water input, respectively, from June 2009 to May 2010. The total N losses via surface runoff ranged from 1.2 to 1.8 kg?ha^?1. Compared with FFP, the SSNM treatment reduced total nitrogen (TN) and dissolved nitrogen (DN) losses by 31 and 34 %, respectively. The results also showed that variations in N losses depended mainly on runoff fluxes, not N concentrations. Runoff samples collected from all treatments throughout the year showed TN concentrations greater than 0.35 mg?L^?1, with the mean TN concentration in the runoff from the FFP treatment reaching 8.97 mg?L^?1. The loss of NO₃ ^?–N was greater than the loss of NH₄ ⁺–N. The total loss of dissolved organic nitrogen (DON) reached 23–41 % of the corresponding DN. Therefore, DON is likely the main N species in runoff from bamboo forests and should be emphasized in the assessment and management of N losses in bamboo forest.     

山地城市暴雨径流污染特性及控制对策

为了解山城重庆的暴雨径流污染特性,充实国内仍然薄弱的基础资料,对4种用地类型的4场暴雨进行了监测,测试指标包括TSS、COD、TP、TN和NH3-N。结果表明,对于坡度2.5%的交通干道和坡度30%的校园人行道,从污染物浓度降幅的角度考虑初期径流的控制量应分别为2～3 mm和1.8 mm。随降雨时间的延长,路面污染物浓度迅速降低,坡度越大,降低速率越快。对于平均浓度,校园屋顶和草坪的各污染物浓度均达到地表水环境质量Ⅴ类标准(总氮和氨氮除外)。交通干道和校园人行道的总磷平均浓度也满足地表水环境质量Ⅴ类标准,但2种下垫面的COD、TN和氨氮平均浓度分别超出地表水环境质量Ⅴ类标准的2～8倍、1.9～3.1倍和1.9～4.3倍。对于交通干道,场次降雨径流的总氮、总磷和氨氮平均浓度与初期浓度的比值和污染物浓度20 min降幅接近(分别为0.5～0.53和50%～55%)接近,而COD和TSS平均浓度与初期浓度的比值和污染物浓度20 min降幅相近(分别为0.35～0.37和78%～84%)。对于校园人行道,污染物浓度20 min降幅均达到90%以上(90%～96%),场次降雨径流的总氮、总磷、氨氮、COD和TSS的平均浓度与初期浓度的比值接近(0.3～0.4)。研究结果为山地城市暴雨径流的污染控制提供了参考。     

Nutrient losses by surface run-off following the application of organic manures to arable land. 1. Nitrogen

Research was conducted on nitrogen (N) surface run-off losses following organic manure applications to land, utilising a purpose-built facility on a sloping site in Herefordshire under arable tillage. Different rates and timing of cattle slurry, farmyard manure and inorganic N and phosphorus (P) fertiliser were compared, over a 4-year period (1993-97). P losses from the same studies are reported in a separate paper. The application of cattle slurries to the silty clay loam soil increased the loss of solids and NH4(+)-N in surface water flow compared to control plots receiving inorganic fertiliser only, or no treatment, but had little effect on NO3(-)-N losses by this route. Results were consistent with other observations that rainfall events immediately after manure applications are particularly likely to be associated with nutrient run-off losses. Losses via subsurface flow (30 cm interflow) were consistently much lower than via surface water movement and were generally unaffected by treatment. Increasing slurry application rate and, in particular, slurry solids loading, increased solids and NH4(-)-N losses via surface run-off. The threshold, above which the risk of losses via surface run-off appeared to be greatly increased, was ca. 2.5-3.0 t/ha slurry solids, which approximates to the 50 m3/ha limit suggested for slurry within UK 'good agricultural practice'. Sealing of the soil surface by slurry solids appears to be a possible mechanism by which polluting surface run-off may occur following slurry application on susceptible soils. Total losses of NH4(+)-N and NO3(-)-N during the 4-year monitoring period were insignificant in agronomic terms, but average soluble N concentrations (NH4(+)-N + NO3(-)-N) in run-off, ranging from ca. 2.0 mg/l, up to 14.0 mg/l for the higher rate slurry treatments. Peak concentrations of NH4(+)-N > 30 mg/l, are such as to be of concern in sensitive catchments, in terms of the potential for contribution to accelerated eutrophication and adverse effects on freshwater biota.     

大豆、龙葵单作和间作对芘污染土壤的修复

土壤多环芳烃(PAHs)污染控制是当前土壤污染防治与保护的热点问题.采用室内盆栽实验,选择PAHs中具有代表性的四环化合物芘(Pyrene)作为研究对象,研究了大豆、龙葵单作和间作对不同浓度芘污染土壤的修复效果.结果表明:低浓度的芘(10 mg/kg)在一定程度上促进了大豆的生长,而高浓度的芘(250 mg/kg)则对大豆的生长有抑制作用;龙葵的生长没有受到芘污染(10~250 mg/kg)的影响;间作对大豆、龙葵的生长均有不同程度的促进作用.污染物芘在大豆和龙葵(成熟期)中的分布情况是:地下部分>地上部分;间作并未对大豆、龙葵中的芘含量造成显著影响.同一污染水平下,不同种植模式的修复效果为:大豆-龙葵间作> 大豆单作 >龙葵单作> 无植物对照.因此,大豆-龙葵间作是一种既能有效修复芘污染土壤,又能充分利用污染土地资源的修复模式.     

Fate of nitrogen during composting of chicken litter

Chicken litter (a mixture of chicken manure, wood shavings, waste feed, and feathers) was composted in forced-aeration piles to understand the changes and losses of nitrogen (N) during composting. During the composting process, the chemical [different N fractions, organic matter (OM), organic carbon (C), and C:N ratio], physical, and microbial properties of the chicken litter were examined. Cumulative losses and mass balances of N and organic matter were also quantified to determine actual losses during composting. The changes in total N concentration of the chicken litter piles were essentially equal to those of the organic N. The inorganic N concentrations were low, and that organic N was the major nitrogenous constituent. The ammonium (NH(4)(+))-N concentration decreased dramatically during first 35 days of composting. However, the rapid decrease in NH(4)(+)-N during composting did not coincide with a rapid increase in (NO(3)(-)+NO(2)(-))-N concentration. The concentration of (NO(3)(-)+NO(2)(-))-N was very low (<0.5 g kg(-1)) at day 0, and this level remained unchanged during the first 35 days of composting suggesting that N was lost during composting. Losses of N in this composting process were governed mainly by volatilization of ammonia (NH(3)) as the pile temperatures were high and the pH values were above 7. The narrow C:N ratio (<20:1) have also contributed to losses of N in the chicken litter. The OM and total organic C mass decreased with composting time. About 42 kg of the organic C was converted to CO(2). On the other hand, 18 kg was lost during composting. This loss was more than half (59%) of the initial N mass of the piles. Such a finding demonstrates that composting reduced the value of the chicken litter as N fertilizer. However, the composted chicken contained a more humified (stabilized) OM compared with the uncomposted chicken litter, which would enhance its value as a soil conditioner.     

添加腐熟污泥对生活垃圾堆肥氮素转化与损失的影响

研究添加腐熟污泥对垃圾好氧堆肥过程中氮素转化与损失的影响,实验设置生活垃圾与腐熟污泥质量比分别为1∶1、2∶1和4∶1,以单独生活垃圾为对照,主要监测堆肥过程中固相（TN、氨氮、硝态氮和亚硝态氮）和气相（NH3和N2O）中氮素转化规律。结果表明：与单独生活垃圾相比,生活垃圾与腐熟污泥比例为1∶1和4∶1时,有机氮与TN损失明显减少;至堆肥结束4组堆体铵态氮与硝态氮相较于堆肥初期均有不同程度提高,其中4∶1组铵态氮与硝态氮提高最多,分别为32.3%和86.1%;亚硝态氮含量在整个堆肥过程中一直处于下降趋势;腐熟污泥的添加使物料堆肥过程中氨气和N2O的释放量随着腐熟污泥添加量的增加而减小。总体而言,由于腐熟污泥对氨气良好的吸附性能和其含有的大量亚硝酸盐氧化菌,加入堆肥后减少反硝化途径N2O的产生,从而减少生活垃圾堆肥过程中氮素损失和温室气体的释放。     

Ammonia emission factors for N fertilizers applied to two contrasting grassland soils

Ammonia volatilization from nitrogen (N) fertilizer applied throughout the year to two soil types was measured using a system of small wind tunnels. Losses from urea ranged from 12 to 46% of the applied N. Small losses, averaging <1%, were measured from ammonium nitrate (AN) and calcium nitrate applications. Factors influencing these losses are discussed. Using these results and those from other workers, emission factors for urea and AN applications to grassland in the UK were determined as 23.0 and 1.6% of the applied N, respectively. Emission factors for these fertilizers when applied to arable land were estimated as 11.8 and 0.8%, respectively. The emission factor for all other applied N (as straight and compound fertilizers) was assumed to be similar to that for AN. Calculations showed that fertilizer applications to agricultural land in the UK contributes 34 kt NH3-N per year, equivalent to 17% of the total annual NH3 emission.