改性炉渣处理低浓度含磷废水试验研究

[目的]探讨改性炉渣处理低浓度含磷废水的最佳工艺条件.[方法]利用盐酸改性的炉渣处理低浓度含磷废水,分析溶液pH、改性炉渣投加量、反应时间、温度等因素对除磷效果的影响,并对改性锅炉炉渣的除磷机理进行了初步探讨.[结果]当溶液pH为8,改性炉渣的投加量为2.0g,反应时间为60 min,温度为35℃时,磷的去除率最高,达96.59％.[结论]该研究为低浓度含磷废水的处理提供了理论参考.     

浮水植物对富营养水体的作用研究

[目的]研究3种浮水植物对富营养化水体中营养盐的去除能力。[方法]选择采自鄱阳湖3种不同的浮水植物(凤眼莲、水浮莲和槐叶萍),利用软隔离小区试验研究了它们对富营养化水体的净化作用效果。[结果]浮水植物处理进行150 d时,3种浮水植物对水体中总氮的去除率分别为槐叶萍(70%)>凤眼莲(67%)>浮水莲(61%);对TP的去除率分别为凤眼莲(56%)>水浮莲(53%)>槐叶萍(49%)。凤眼莲和槐叶萍处理围区的水质净化效果较好,这与植物自身吸收同化污染水体中氮素、磷素的能力大小及植物根系微生物的作用都有关。凤眼莲和槐叶萍在提高水体透明度方面效果也较好。[结论]凤眼莲和槐叶萍的长势最佳,生长周期长,对水体中总氮和总磷的去除效果最好,对其他水质指标的改善效果也最好。     

鱼类对浅水湖泊生态系统及其富营养化的影响

鱼类群落结构影响着湖泊的水质和水体的自净能力。分析了鱼类在浅水湖泊生态系统的作用,以及对富营养化的影响,并提出了基于富营养化控制的鱼类群落管理对策,即通过放养滤食性、肉食性鱼类以及减少食浮游动物和杂食性鱼类等方式,对湖泊鱼类群落进行调控,以优化湖泊生态系统结构,增强水体自净能力和改善水质。     

湖泊底泥氮营养释放特征研究

通过模拟培养,研究了底泥氮营养的释放及上覆水体中氮营养的浓度变化特征。结果表明,在扰动下,底泥向上覆水体明显地释放氮营养,而消亡的水华更可以激发底泥中有机氮的释放,底泥中有机氮的矿化释放与沉积到底泥表层的水华量密切相关。释放进入上覆水体中氮首先以铵氮存在,并快速向亚硝氮转化,此后才向硝氮转化。水中铵氮浓度高,存在时间长,是比较主要的氮形态。     

Soil Sample Depth in Pasture Soils for Environmental Soil Phosphorus Testing

Phosphorus (P) in runoff from agricultural land is a major contributor to eutrophication of surface waters. This study investigated the relationship between dissolved P in surface runoff and soil-test P measured at different sample depths (0–2 and 0–10 cm). Soil at these depths was collected from 136 sites in southeast New South Wales, Australia, under pastoral agriculture, covering a wide range of soil types and land-use intensity, from native pasture to intensive dairying. Bicarbonate-extractable soil P concentrations at these two depths were curvilinearly related over a very wide range of P (r² = 0.91). Small-plot rainfall simulations were conducted at 14 of these locations, for which the relationship between the sampling depths was even closer (r² = 0.95). After dividing the soils into two groups based on parent material (basalt and nonbasalt), linear relationships were found between extractable soil P and runoff dissolved reactive P, with more of the variance being accounted for with the sedimentary soils (r² = 0.89, 0–10 cm; 0.91, 0–2 cm) compared with basalt soils (r² = 0.63; 0–10 cm; 0.57, 0–2 cm). The results suggest that agronomic soil P testing in pastoral soils (typically 0–10 cm depth) is sufficient for estimating the potential for losses of P in runoff and that there is no need to collect shallow soil samples especially for this purpose.     

Assessing extractable soil phosphorus methods in estimating phosphorus concentrations in surface run‐off from Calcic Hapludolls

Understanding soil test phosphorus (STP) and surface run‐off phosphorus (P) relationships for soils is necessary for P management. The objective of the study was to evaluate the efficacy of various soil test indices to predict P losses in surface run‐off. Selected sites were subjected to in situ rainfall simulations according to the protocol of the National Phosphorus Research Project ( NPRP, 2001 ). P from a composite of twenty‐four 2.0‐cm‐diameter core soil samples (0–5 cm) was extracted using the Olsen, Bray–Kurtz, Mehlich III, distilled water and 0.01 m calcium chloride procedures. All of these P extraction methods explained a significant amount of variability in surface run‐off total dissolved P [TP (<0.45)] (r² ≥ 0.67; P ≤ 0.01), where 0.45 is the filter pore diameter in microns. Multiple regression models showed extractable P to be the best soil predictor of surface run‐off TP (<0.45) among the studied soils. Despite extraction method or soil type, extractable P was the best soil predictor of surface run‐off TP (<0.45). Either agronomic (0.92 ≤ r² ≤ 0.96) or environmental (0.94 ≤ r² ≤ 0.96) soil tests were effective in estimating surface run‐off TP (<0.45) in select Mollisols.     

惠州西湖生态恢复中营养盐和浮游生物监测

惠州西湖是典型的热带浅水富营养化湖泊,于2004年底建立示范区,进行了鱼类调控和水生植被修复。2005年1～10月的调查结果表明:示范区总磷、悬浮物、叶绿素a的含量分别比未修复的平湖低64.0%、80.0%、63.5%,水体透明度提高了3倍以上;示范区浮游植物优势种趋向贫-中营养种类,以硅藻为主,平均密度和生物量比未修复的平湖分别低98%和93%;示范区浮游动物种类增加,丰度显著减少,优势种趋向清水态种类,大型种类增多。说明生态修复改善富营养化水质取得了良好的效果。     

水培蔬菜对藕田富营养化水体的净化研究

[目的]研究生菜和油菜对富营养化水体N、P和有机物的净化效应及其处理后的品质。[方法]以生菜和油菜为试验材料对藕田富营养化水体进行生物净化试验。[结果]生菜和油菜生长体系对水体中总磷(TP)的去除率分别为95.30%和96.38%,对水体中氨氮(NH4+-N)的去除率分别为97.18%和98.05%,对总氮(TN)的去除率分别为82.94%和87.64%,对化学需氧量(CODcr)的去除率分别为24.03%和27.76%;水培生菜和油菜可食部分的重金属含量和硝酸盐含量均低于国家相关标准,生菜和油菜对富营化水体的净化效果较好。[结论]试验所用生菜和油菜对富营养化水体具有一定的耐受能力,在试验条件中生长良好,并能有效地降低水体中的TP、NH4+-N及TN的浓度。水培生菜和油菜可食部分符合食用标准,具有一定的推广应用价值。     

象山港中部养殖海区营养盐的季节变化及富营养化

根据2014年11月,2015年1月、3月和7月在象山港中部养殖海区开展的海洋调查所获得的海水营养盐数据,分析了该海域营养盐含量的季节变化,评价了海水的富营养化状况。结果显示,该海域无机氮平均含量秋季最高,春季次之,冬季最低;活性磷酸盐平均含量秋季最高,夏季次之,冬季最低。对不同养殖区域分析,宁海海藻养殖区和西沪港海带养殖区的无机氮浓度除冬季1个站位点外均劣于国家海水四类水质标准(0.50 mg/L),活性磷酸盐浓度在春、秋两季劣于国家海水四类水质标准(0.045 mg/L)。全年各水层的N/P比值均高于Redfield比值,磷相对缺乏。根据富营养化评价模式,象山港中部养殖海区营养水平属于磷中等限制潜在性富营养型。     

三峡库区长江干流和支流富营养化研究

长江上游重庆段人口密集,由于历史的原因,环境方面基础设施落后,大量未经处理的工业废水、城市生活污水、船舶污染物和大面积的农田地表径流汇入长江及次级河流。特别是三峡大坝建成蓄水之后,主河道和支流水体流动明显变缓,加之长距离回水,部分次级河流自2003年起明显富营养化,并有逐渐加重的趋势。本文综合了2002～2009年对长江三峡水库入库河流营养状态的研究,得出了次级河流水体综合营养状态的评价,并结合三峡库区现有污水和垃圾处理设施处理能力与实际排放量的分析,对于库区支流富营养化趋势进行预测。最后,通过总结国内外已提出的许多行之有效的富营养化防治措施,对三峡库区的富营养化防治提出一些建议。