磷在富营养化湖泊沉积物-水界面的循环

沉积物中部分固定的磷可通过分解或溶解作用而释放磷酸盐到沉积物间隙水中;再生的磷可能释放到上覆水体中,或在沉积物中作为一种自生相而再沉淀,或被沉积物的其它组分所吸附。本文描述了磷在沉积物-水界面的迁移过程,并对影响磷循环的因子及其磷自沉积物释放的机制作一简要概述。     

岱海表层沉积物中影响氨氮释放的模拟研究

以北方半干旱地区典型内陆封闭湖泊岱海为研究对象,采用室内模拟实验方法,开展了温度、pH、溶解氧及水生植物对湖泊沉积物中NH4^＋—N释放的影响研究。结果表明,温度升高,中性条件,厌氧条件均有利于NF4^＋-N的释放。狐尾藻对上覆水NH4^＋-N含量的有效控制作用是其抑制底泥释放、同化吸收作用和增强上覆水氧化条件等综合作用的结果,植物修复是控制湖泊富营养化水平的有效措施。     

不同水动力下湖泊沉积物重金属释放通量

为探讨不同水动力下湖泊沉积物重金属释放通量,该文在室内可循环式水槽试验中模拟了动水条件下沉积物的运动,试验时通过控制闸门开关改变水槽内水体流速,探讨了不同水动力下沉积物的悬浮与释放规律。以鄱阳湖沉积物为水槽试验沉积物,通过分析沉积物中Cu、Zn、Cd、Pb浓度的变化,建立了当沉积物粒径为50~200μm时,沉积物中Cu、Zn、Cd、Pb释放通量与流速的关系式。结果表明:释放通量随水体流速增大呈指数增长,当流速分别为15、35、65 cm/s时,Cu释放通量分别为45.82、65.18、127.16 mg/(m~2·d);Zn为104.35、139.82、220.5 mg/(m~2·d);Cd为0.116、0.163、0.28 mg/(m~2·d);Pb为4.78、6.72、11.57 mg/(m~2·d),鄱阳湖水体重金属浓度计算值与实测值误差在5%~20%范围内。研究结果可为湖泊重金属污染控制及治理提供科学依据。     

磷和硅在湖泊沉积物上的释放特征及形态变化研究

以乌梁素海（WLSH）和岱海（DH）表层沉积物为吸附剂,开展了磷硅在2个湖泊沉积物上的释放实验研究,同时采用连续提取法探讨了释放后的磷硅形态变化。结果表明,磷和硅在2个湖泊沉积物上的释放行为均可用Elovich方程描述;0～20min为磷的快速释放阶段,此时段内约有75%的吸附磷迅速从沉积物上解吸并释放至上覆水中;0～2h为硅的快速释放阶段,此阶段内约有40%的吸附硅从沉积物上解吸并释放至上覆水中;总体上,沉积物中Ex-P、Al-P、Fe-P及IEF-Si、CF-Si具有较强的释放潜力。     

哈素海表层沉积物中内源磷的释放研究

以浅水湖泊哈素海为研究对象,开展了上覆水质、温度、pH、溶解氧、扰动和光照等环境要素对湖泊沉积物内源磷释放的影响试验研究。结果表明,温度升高、碱性条件、厌氧和强烈的扰动作用等均有利于内源磷的释放,而照度则间接地限制了沉积物释磷对上覆水中磷浓度的影响。HSH-2、HSH-5和HSH-6等3个站位TP的最大释放量在自然光照条件下分别为1.53、1.39和1.27 mg·kg^-1,避光条件下分别为1.77、1.52和1.52 mg·kg^-1;静置条件下分别为1.42、1.38和1.68 mg·kg^-1,R=60 r·min^-1时分别为1.75、1.50和2.00 mg·kg^-1,R=120 r·min^-1时分别为2.52、2.64和4.02 mg·kg^-1;在pH=11时释放量最大,分别为10.82、6.83和16.68 mg·kg^-1。各环境因子中,以pH和扰动对哈素海沉积物内源磷的释放影响最大。哈素海为浅水湖泊,在湖水咸化程度逐渐增高的条件下,将会导致湖泊沉积物内源磷的大量释放,从而将进一步加剧水体的富营养化。     

藻类生长对滇池沉积物磷释放影响的研究

室内对滇池沉积物进行藻类生长模拟试验,结果表明,以沉积物作为唯一P源进行培养,滇池藻类依然可以正常生长;沉积物在藻类生长的影响下,具有较强的P释放潜力,释放速率可达19.2mg/(m2·d);藻类生长对P的大量需求,是通过OH-对沉积物Fe结合态P阴离子置换,和对金属离子Fe的有机蝥合以增加被结合态P的解吸两种主要途径获得的,藻吸收利用沉积物中P的形态主要为Fe结合态P。     

环境条件变化对滇池沉积物磷释放的影响

在实验室控制条件下,以滇池表层新鲜沉积物和湖水为材料,研究了氧化还原状况、水体扰动、pH值等环境因子对沉积物P释放的影响。结果表明,与好氧条件相比,厌氧状态大大促进沉积物中P的释放,最大释放量为3.96mg。随着湖水pH值的升高,沉积物的释P量明显增加,碱性条件下P释放量是中性条件的几百倍。水体扰动对沉积物P释放的影响不大。不同环境因子相比,湖水在碱性条件下(pH10.5)P的释放速率最大,高达68.04mg/(m2·d),厌氧条件次之,变化在7.73~8.91mg/(m2·d),对照和扰动条件下P释放速率很低。湖水pH值增加和氧化还原电位降低是滇池沉积物释P的主要机制。     

不同腐殖酸组分对湖泊沉积物中重金属释放的影响

腐殖酸作为湖泊沉积物中有机质的主要成分．对重金属具有强烈的富集能力，从而影响湖泊沉积物中重金属向水中的释放。本文深入探讨了腐殖酸的不同组分对沉积物中Cu、Zn、Pb、Cd向水中释放的影响。结果表明：腐殖酸的添加使沉积物中重金属的释放置明显受到影响。Cu、Zn、Pb、CA4种重金属随着胡敏酸和富里酸的添加．释放量逐渐增加，并且两种腐殖酸的用量越大．重金属的释放量越大。向沉积物中加入同等量的胡敏酸、富里酸，两种腐殖酸对重金属释放的促进作用胡敏酸〉富里酸。向沉积物中加入不同用量的富里酸FA，沉积物中Cu、Zn、Pb、Cd的释放率分别为73％～80％，18．5％～22％，7．5％～10％．97％～99％；而在相同条件下，向沉积物中加入不同用量的胡敏酸HA，对以上4种重金属的释放率分别为66．5％～72％，15．5％～19．5％．6％～8．5％，96％～98．5％。在腐殖酸用量相同的情况下，溶液的pH对沉积物中重金属的释放也会产生影响。即随着pH值上升．释放量逐渐减少。当pH=8时，释放量基本上已不再发生变化，说明此时沉积物中的重金属基本上与腐殖酸的羧基反应完毕。     

水生植被原位恢复对底泥磷释放的影响

选取太湖五里湖水生植被生态重建大型围隔(105 m2)为试验区,进行了水质和沉积物内源释放2a的同步跟踪监测。结果表明,围隔内挺水植物区和沉水植物区PO34-—P和NH4+—N的年平均浓度分别比围隔外对照区下降了54.6%,46.7%和17.1%,13.8%;围隔内水质得到明显的改善。通过室内静态模拟不同实验区沉积物中磷酸根的释放实验,发现围隔内沉水植物区和挺水植物区PO34-—P的释放速率的年平均释放速率分别为0.23±0.42mg/(m2.d)和-0.38±0.65mg/(m2.d),明显低于围隔外对照区﹝1.13±1.31mg/(m2.d)﹞。因此重建和恢复湖泊水生植物系统能有效抑制内源磷酸盐向水体的释放。     

去除有机质对城市浅水湖泊氮磷释放特征的影响

[目的] 分析南昌市浅水湖泊象湖表层沉积物的释放特征及有机质对氮、磷释放的影响,为城市内浅水湖泊治理中富营养化控制提供理论依据。[方法] 通过释放动力学试验以及释放潜能试验研究了城市浅水湖泊氨氮（NH₄⁺-N）和溶解性活性磷（SRP）的释放特征,以及与通过H₂O₂去除有机质后的释放特征进行了对比。[结果] 去除前后的氮磷的释放速率都是先由一个较快的过程逐渐变慢最后趋于稳定达到最大释放量（Q_max）。去除有机质后NH₄⁺-N的释放平衡时间缩短,SRP则几乎不变。去除有机质后,NH₄⁺-N的最大释放量（Q_max）与有机质含量呈显著正相关,而SRP与有机质无显著相关性。[结论] 影响沉积物氮磷释放的因素多样,其中高等水生植物丰富的区域对磷的释放有明显的抑制作用。沉积物有机质的含量越高沉积物氮的最大释放量（Q_max）也越高,磷的的最大释放量（Q_max）则受有机质含量、活性、组成成分、吸附与结合的铁铝磷含量等因素共同影响。     

添加剂在猪粪堆肥过程中的作用研究

添加剂是指为了加快堆肥进程和提高堆肥产品质量,在堆肥物料中加入的微生物、有机或无机物质。本文通过室内培养与室外堆肥试验,研究不同添加剂对猪粪发酵过程中臭味及氮素损失的影响。结果表明,使用本研究中所采用的添加剂与发酵工艺,可以减少猪粪发酵中氨的挥发、氮素损失与猪粪的恶臭。75%含水量的猪粪经过20d的发酵,可达基本腐熟程度。添加剂可以优化堆肥过程的环境条件,提高微生物活性;加快堆肥的腐熟;减少氮素损失,保持养分含量;调节堆肥中各种营养元素的含量,提高堆肥质量。     

环境条件变化对瓦埠湖沉积物磷释放的影响

拟议中的“引江济淮”调水工程涉及到长江、淮河两大河流，瓦埠湖为其中的一个重要湖泊，其水质是否受到调水的影响为该工翟关注的环境问题之一。分析了外界环境因子变化对瓦埠湖底泥在不同环境条件下以及干、湿沉积物样品磷释放的差异，环境因子分别选取了不同磷浓度的上覆水、光照、pH、温度、DO、微生物、水体扰动等。结果表明：湿样释磷能力明显高于风干样品；上覆水体磷的浓度对底泥释磷能力有较强的调节作用；光照对底泥释磷影响不明显，但温度对底泥的释磷有较明显的影响，磷的最大释放量与之呈正相关；水动力条件的改变可在短期内使底泥达到最高的释放量．而DO、pH的改变也可不同程度地增加底泥的释磷能力。综合瓦埠湖底泥的释磷特征与湖泊水文状况，认为调水工程使得底泥释磷的地球化学行为较易实现。     

多源沉积物对地表水中磷铜锌浓度的影响

受多来源沉积物污染影响的水体中可溶性P,Cu,Zn实际浓度常明显低于按各自沉积物的比例与释放量计算的理论值。沉积物之间的性质差异越大,实际测定值与计算值之间的差异也越大。多来源沉积物水体中可溶性P,Cu,Zn的浓度主要受P,Cu,Zn释放能力最强或对P,Cu,Zn吸持能力最强的沉积物比例控制。     

Reactions of phosphorus with sediments in fresh and marine waters

Abstract. The interactions of P with soils and sediments are examined in the context of transport processes from land, through rivers to estuaries and coastal waters. In soil erosion, selective size fractionation and preferential sorption to finer solids is crucial in the transport of P to water courses. Problems in quantifying the sorption affinity and equilibrium phosphate concentration (EPC) of mixtures of different soils and sediments are identified. Riverine transport of P by suspended solids is usually very important and examples of the changes in the amount and composition of particulate P (PP) concentration during storm events are discussed. Increased P content of solids during the first autumn storms, probably reflect the resuspension of accumulated stream bed-deposits. The fate of P in estuaries and their importance as possible long-term sinks of P are discussed. The relatively high concentrations of dissolved P associated with riverine inputs are to some extent buffered by the relatively high concentrations of suspended sediments resulting from tidal flows. Phosphorus may be released during transport to the sea due to decreases in the EPC, increases in salinity and release from bottom sediments as a result of low oxygen conditions.     

Phosphorus Retention and Release Characteristics of Sewage-Impacted Wetland Sediments

Sediment deposited in traps positioned along a sewage-impacted wetland receiving phosphorus (P)-retaining reactants from natural wetland water was fractionated into different particle sizes, and the amount of P retained in these particle sizes was investigated. Subsamples of the sediments collected from different sites along the wetland system were also equilibrated with water at different water:sediment ratios and equilibration periods to investigate the extent of P released from these sediments under aerobic and anaerobic conditions. Results obtained showed that most of P deposited in sediments is in fine fractions (<16 µm), particularly in sediments collected from confluence sites where water inflow from the natural wetland provides P-retaining reactants and from sites immediately below these confluence sites (postconfluence sites). The extent of P release from sediments depended on the aerobic-anaerobic conditions of the sediments, equilibration period, water:sediment ratio and the position of sites within the wetland. The rate of P released from sediments associated with an increase in equilibration period tended to be higher under aerobic than anaerobic conditions. Water:sediment ratio was found to be a more important factor in controlling the release of P from sediments under anaerobic than aerobic conditions. The amount of P released from the confluence and postconfluence sites was higher than that from other sites over a range of equilibration periods and water:sediment ratios under aerobic and anaerobic conditions.     

砂质土壤磷素的组成特点与释放规律研究

砂质土壤磷素主要以可提取态形式积累,有很高的释放潜力。该类土壤磷素的释放受土壤pH、土水作用时间和土壤溶液化学组成等的影响。土壤酸化、土壤溶液中Na+浓度的提高及土壤与水的作用时间增加可促进土壤磷素的释放。用淋洗方法和平衡提取等2种方法对土壤磷素的释放评价表明,淋洗方法测得的P量较小,可代表土壤短期内P释放强度;而平衡提取法提取的P数量较大,可代表土壤P长期释放的容量。     

Effects of Hydrilla Verticillata on Phosphorus Retention and Release in Sediments

Submerged macrophytes are commonly used for the environmental engineering of the controlling of shallow lake eutrophication, and are also an effective and valid alternative for the remediation of eutrophic water bodies, not only under experimental conditions but also under natural conditions. Therefore, the effects of submerged macrophytes on the improvement of shallow lake water quality have been intensively investigated. But the mechanism was not well understood, especially the mechanism of the effects of submerged macrophytes on the exchange of nutrients at sediment–water interface in shallow lakes. This study selected a familiar submerged macrophyte Hydrilla verticillata in China and evaluated the effects of H. verticillata on the phosphate retention and release at the lake sediment–water interface in a simulated condition. The effects of H. verticillata on the phosphate sorption isotherm, phosphorus (P) availability were investigated and the subsequent kinetics of P release was also measured by repeated extraction with CaCl₂ solution. Exchangeable Ca and ammonium oxalate-extractable Fe (Fe_ox) and Al (Al_ox) of the sediments were also determined. The results show that the contents of organic matter, cationic exchange capacity (CEC), Ca, Fe, Al, exchangeable Ca, Fe_ox and Al_ox of the sediments with H. verticillata were higher than those of the control sediments, and the contents of total phosphorus (TP), Olsen-P and reactive dissolve phosphorus (RDP) were lower. The sediments with H. verticillata had stronger P sorption ability and weaker ability of P release. H. verticillata did not significantly affect the trends of the sorption isotherms and kinetics of the released P on the sediments. H. verticillata can significantly increase the ability of P sorption, decrease in the ability of P desorption on sediments was one of the mechanism that maintained lower P levels of the overlying water through affecting the contents of organic matter, CEC, Ca, Fe, Al, exchangeable Ca, Fe_ox and Al_ox in sediments.     

Effects of floating Azolla on phosphorus fluxes and recovery from former agricultural lands in wetland microcosms

The long-term fertilization results in accumulation of phosphorus especially in the top layer of the soils. Inundation of agricultural lands leads to a switch to anaerobic soil condition, causing reduction of iron and leaching of phosphate simultaneously. From the ecological and environmental perspective, high nutrients flux especially phosphorus will increase the possibility of eutrophication in aquatic system. The fern Azolla had a good potential to adsorb phosphorus, it also has distinctive nitrogen-fixing capacity. We conducted a 10-week aquarium experiment to investigate the phosphorus release capacity from two agricultural soils in the Netherlands with different Fe and P concentrations but comparable Fe/P ratios. Besides, the research questions rose to whether Azolla could use the mobilized phosphate released from the soils for growth. We also tried to find an effective indicator to estimate the actually phosphate mobilization from sediment to water layer. Results showed that the soils with high Fe and P concentrations had higher phosphate release rate compared with the soil with low Fe and P concentrations. Pore water Fe: PO₄^3? ratios were valid to identify P release to surface water, when the Fe: PO₄^3? ratios less than 8 mol mol^?1 substantial phosphorus mobilization occurred. The conclusions showed that the actual mobilization of phosphate is more important than the phosphorus retained in the sediments for the internal PO₄^3? fluxes. From 10-week experimental results, we found that Azolla can reuse the phosphate retained in soils thus removed the mobilized phosphate in a moderately low surface water nutrient loading.     

不同土壤磷的固定特征及磷释放量和释放率的研究

通过加入不同浓度的P(水土比为 2 0∶1 )并利用连续提取法 ,对三种土壤P的固定特征以及磷的释放进行了研究。结果表明 ,红壤对P的固定能力高于潮土 ,而潮土高于水稻土 ,在加入P量为 2 97gkg- 1土壤的条件下 ,三种土壤对P的固定量分别为 2 84gkg- 1、2 5 3gkg- 1和 2 0 8gkg- 1。三种土壤对P的固定率则随着加入P量的增加而降低。在P的释放研究中 ,随着提取次数的增加 ,P的释放量减少 ,并在提取 8次后 ,以后各次P的释放量不发生显著变化。三种土壤中 ,水稻土P的最大释放量 (1 2 4 0 7mgkg- 1)显著高于红壤 (60 46mgkg- 1)和潮土 (1 9 74mgkg- 1) ,水稻土P的总释放量 (1 6次 )也大于红壤和潮土 ,三种土壤P的总释放量分别为 2 0 6 0 2 (1 98gkg- 1土壤P处理 )和 2 71 91mgkg- 1(2 97gkg- 1土壤P处理 )、1 0 0 48和2 60 5 3mgkg- 1、1 1 6 0 6和 1 3 1 91mgkg- 1。三种土壤P的释放率随着提取次数的增加而增加 ,并逐渐达到稳定。水稻土的释放率显著高于红壤和潮土。水稻土和潮土中 ,1 98gkg- 1土壤P处理的土壤P的释放率高于2 97gkg- 1土壤P处理的土壤 ,红壤则相反