大薸对奶厅废水主要污染物的去除效果研究

为探索低成本高效率的奶厅废水处理新技术,本研究以大薸（Pistia stratiotes）为研究对象,选择某奶牛养殖场奶厅废水原水、厌氧处理后和好氧处理后的废水开展室内试验,重点研究大薸对奶厅废水中主要胁迫盐分的耐受浓度阈值,以及大薸对奶厅废水中基础养分（TN、TP、COD等）和阴离子盐（SO₄^2-、Cl^-等）的去除效果。结果表明：当奶厅废水的电导率未超过2 193~2 527 μS·cm^-1时,大薸对奶厅废水中的盐分具有耐受性。但当奶厅废水中两种主要阴离子盐SO₄^2-和Cl^-含量分别超过5 mmol·L^-1和15~25mmol·L^-1时,大薸抗氧化酶活性受到抑制。在净化三类奶厅废水的过程中,大薸对水体COD的削减作用最为明显,减少了65.51%~86.75%,TN、NH₄⁺-N和TP含量分别降低了69.46%~87.52%、64.00%~96.59%和30.73%~66.02%,而SO₄^2-和Cl^-分别被大薸吸收了16.37%~18.04%和22.02%~35.83%。此外,大薸处理时间为23 d时,对奶厅废水原水和厌氧处理后的废水中多种污染物的去除效果最好。奶厅废水经厌氧处理后,大薸对多种污染物的削减作用更为明显,对水体中TN、NH₄⁺-N、TOC、SO₄^2-和Cl^-的去除效果较原水分别提升了9.60%、42.83%、40.94%、2.00%和13.81%。研究表明,大薸对奶厅废水中盐分具有耐受性,且奶厅废水经厌氧处理后大薸可以更为有效地降低其中主要污染物含量。     

栅条式清杂装置机理分析与优化试验

残膜清杂是残膜回收的重要环节,现有机型的清杂装置存在清杂效果差及工作不可靠的缺点。为此,结合夹指链式残膜回收装置的改进设计与试验,提出了一种基于倾斜栅条的清杂装置。通过对该装置清杂机理进行分析,采用Box-Behnken响应面试验设计方法建立起清杂率与栅条间距b、栅条角度α、栅条长度L间的二次回归模型。通过分析模型响应曲面,寻得最优方案,确立了栅条式清杂装置的结构与尺寸。田间试验表明:当栅条间距为75mm、栅条角度为51°、栅条长度为870mm时,清杂率达85.35%。由此证明了优化方案的可行性,可为相关残膜清杂装置的研究提供理论依据。     

齿盘式秸秆移位装置设计与试验

针对江苏地区油菜免耕播种机作业时存在易堵塞、种床清洁率低等问题,设计一种齿盘式秸秆移位装置,通过运动力学分析确定秸秆移位的重要影响因素,使用离散元仿真软件进行仿真试验,得出秸秆移位装置工作时的最佳参数组合,最后进行台架试验验证仿真试验准确性。仿真试验结果表明秸秆清除率与位移偏角以及前进速度均呈现正相关的关系,当前进速度一定时,位移偏角越大,装置的秸秆清除效果越好;当位移偏角一定时,前进速度越大,装置的秸秆清除效果越好。当前进速度为0.6 m/s、位移偏角为30°时,秸秆清除率达到最大值64.70%。台架验证试验表明,当机具前进速度为0.6 m/s、齿盘位移偏角为30°时秸秆清除效果较好,此时秸秆清除率为60.69%。试验结果表明齿盘式秸秆移位装置的设计基本满足油菜播种的要求。     

凤眼莲动态模块化治理湖泊污染的设计

指出了环境生态工程采用生态学理论,强调将环境问题于系统内解决,使受污染的环境能够适时与周边的大自然友好和谐地融为一体,注重经济效益和生态效益的高度统一,已经逐步发展为最受欢迎的修复水体的技术之一。凤眼莲是修复污染湖泊的良好先锋植物,但其易泛滥成灾和含水量甚高的特性限制了人们对其大规模的使用。本着环境生态工程的理念,建立了凤眼莲动态模块化的浮床装置,利用风能为浮床装置提供电能,结合装置内的螺旋桨动力结构使浮床移动,通过旋转吊臂滑轮和底部尼龙网结构使凤眼莲机械化原位去水。此设计在实现低廉、高效治理水体富营养化和重金属等污染问题的同时,也有效解决了凤眼莲可能泛滥成灾的隐患,达到生态效益、经济效益和景观效益的协调统一。     

Zr-ATP复合吸附剂的制备及其吸附除磷效果探究

指出了磷是导致水体富营养化的核心元素之一,利用碱酸复合改性凹凸棒石（ATP）,经成型处置制备了一种新型ZrATP复合吸附材料,考察了其对水中磷酸根的吸附性能。结果表明：成型的Zr—ATP复合吸附剂在常温、常压下进行静态除磷实验,除磷效率达99％,吸附容量达7．7mg／g,是值得进一步深化研究的富营养化修复剂。     

油酸酰胺去除蓝藻水华的野外围隔原位试验

利用油酸酰胺进行野外围隔原位除藻试验。结果表明,在整个试验周期内(31 d),投放油酸酰胺后水体叶绿素a含量均低于对照,而水体透明度均高于对照;投放油酸酰胺后的第1~10 d,水体氨氮含量较对照有所降低,但是在第10 d以后与对照相比无明显差异;投放油酸酰胺后,水体总磷含量在第3~17 d低于对照,到第31 d时却高于对照。水体微囊藻毒素检测结果显示,投放油酸酰胺对水体微囊藻毒素含量没有明显影响。这说明油酸酰胺能有效解除蓝藻水华危机,是一种具有除藻应用潜力的杀藻物质。     

壳聚糖吸附去除水中腐殖酸的研究

研究了壳聚糖对溶液中腐殖酸的去除效果,探讨反应进行时间、pH值、壳聚糖初始浓度、腐殖酸初始浓度、各金属离子浓度等因素对壳聚糖去除溶液中腐殖酸效果的影响。结果表明,pH值是影响壳聚糖吸附腐殖酸的重要因素,适宜pH值是6;初始吸附过程非常快,壳聚糖的浓度为20mg·L-1,吸附20 min时去除率即达到84.9%。在一定浓度范围内(25～150 mg·L-1),Ca2+、Na+、K+的存在对壳聚糖吸附性能的影响是比较微小的。     

膜式氧合器不同解吸方式对水产养殖水体中氨氮去除效果的影响

研究了膜式氧合器3种不同解吸方式，即：O2对流法、真空抽取法和酸吸收法去除水产养殖水体中氨氮的影响因素，并比较对其氨氮的去除效果。结果表明，氨氮初始浓度和pH是氨氮去除率的主要影响因素；当pH＞9时，O2对流法和真空抽取法对氨氮去除效果比pH＜9时要高，而酸吸收法不论pH高低时比其它2种方法都能获得较高的氨氮去除率。     

Phosphorus removal in a marine prototype, recirculating aquaculture system

Phosphorus dynamics were examined in a prototype, zero-discharge, marine-recirculating system. Operation of the system without discharge of water and sludge was enabled by recirculation of effluent water through two separate treatment loops. Surface water from the fish basin was pumped over a trickling filter in one loop, while bottom-water was recirculated through a sedimentation basin followed by a fluidized bed reactor in the other treatment loop. Ammonia oxidation to nitrate in the trickling filter and organic matter digestion together with nitrate reduction in the sedimentation basin and fluidized bed reactor were the main biological features of this treatment system. Orthophosphate concentrations did not exceed 15 mg PO₄–P/l in the culture water during more than 1 year of system operation. Much of the phosphorus was retained within the sedimentation basin and fluidized bed reactor. In these treatment stages, the phosphorus content of organic matter was as high as 17.5% and 19%, respectively. High concentrations of total phosphorus and low concentrations of soluble orthophosphate were measured in the initial stages of sedimentation under oxic and anoxic conditions, suggesting that most of the phosphorus was associated with organic matter. Depletion of oxygen and nitrate in the sludge layers of the sedimentation basin coincided with sulfate reduction to sulfide and a release of soluble orthophosphate. The observed phosphorus dynamics in this marine system supported findings from previous studies in which it was demonstrated that denitrifiers underlie phosphorus immobilization under these conditions.     

Effect of Manually Preheparinized Syringes on Packed Cell Volume and Total Solids in Blood Samples Collected from American Alligators (Alligator mississippiensis)

The hemodilution effect of manually preheparinized syringes was determined by evaluating the packed cell volume (PCV) and total solids (TS) from blood samples collected from 50 American alligators (Alligator mississippiensis). A volume of 0.2 mL of blood was drawn into 3 syringes of 1 mL: control with no heparin sodium, heparin sodium drawn to 0.1 mL and then expelled, and heparin sodium drawn to 0.2 mL and then expelled. PCV and TS values were determined from each syringe immediately after collection. Mean PCV and TS values were compared between the control and heparin groups using linear mixed modeling. The syringes coated with heparin resulted in a significantly lower mean PCV and TS values when compared with controls, with no significant difference between the heparin groups. This dilution effect was also found to be inconsistent and not accurate from one syringe to another. An adjunct method of obtaining 0.5 mL from already-collected blood samples into 1-mL syringes that were coated with heparin drawn to 0.2 mL and then expelled also showed a significant decrease in PCV and TS values when compared with the control samples, although to a lesser extent. As a result, it cannot be recommended to manually preheparinize syringes when collecting small volume of blood samples from American alligators because significant and unpredictable hemodilution is likely to occur.