添加氮损失抑制剂对蓝藻泥堆肥质量的影响

对脱水蓝藻进行大型生产性堆肥实验。研究堆肥过程中,氮损失抑制剂过磷酸钙的添加对堆肥物料各类理化性质的影响。研究结果表明,过磷酸钙加入的处理组与未加过磷酸钙的对照组堆制37 d后堆肥物料均可腐熟,且堆肥肥效均符合NY525-2002的相关要求。添加过磷酸钙处理组有机质含量为490 g/kg,全N、全P和全K含量分别为20.75、10.02和11.32 g/kg,总养分含量达到9.77%,堆肥品质明显优于对照处理。同时,在微生物的作用下,对照组中微囊藻毒素MC-RR与微囊藻毒素MC-LR去除率分别达到89.8%与78.3%。值得一提的是,添加过磷酸钙后,MC-RR和MC-LR的去除率得到进一步提高,分别达到了92.96%和100%,较好地保证了蓝藻堆肥农用的安全性,为脱水蓝藻好氧堆肥化提供了可行性依据。     

电吸附对水中盐类、氨氮、COD的去除效果分析

电吸附技术作为高效、环境友好型的除盐、除氨氮技术,可应用与水的深度处理领域内。为了使污水回用达到工业用水的水质标准,对电吸附去除水中盐类、氨氮、COD的效果进行分析,结果表明,电吸附设备处理不同氨氮浓度的废水,对中低浓度的氨氮去除效果稳定,当进水氨氮浓度低于20 mg/L时,处理后出水氨氮浓度低于5 mg/L,COD浓度小于25 mg/L,达到回用标准;随着进水盐浓度的增大电吸附处理效果逐渐变差,在电导率低于2 500 μS/cm时除盐率在75%左右,氨氮去除率达到70%左右,COD去除率达到60%左右。经电吸附处理后的低氨氮浓度废水,TDS、氨氮浓度均可达到工业回用水标准。     

水泥窑协同处置过程中Pb、Cd的挥发特性

对铅、镉2种重金属的氧化物开展了热重实验、熟料煅烧以及熟料消解实验,以重金属的挥发率为主要指标,研究了水泥窑协同处置过程中铅、镉在等温条件下随时间的挥发特性。结果表明,2种重金属的挥发率均是随温度的升高,时间的增加而增大。Pb的挥发率为96%,Cd的挥发率达到98%,根据等温动力学及阿累尼乌斯方程,对Pb,Cd的挥发率随时间变化的规律进行动力学模拟,得到较好的线性拟合效果,其中,Pb挥发反应的表观活化能E为88.73 kJ/mol,Cd挥发反应可以分2个部分：1 200℃以下的表观活化能E为61 kJ/mol;1 250℃以上的表观活化能E为184.6 kJ/mol。     

Temperature-dependent sorption of polycyclic aromatic hydrocarbons on natural and treated sediments

In aqueous environment temperature is considered to play a significant role in the sorption process of polycyclic aromatic hydrocarbons (PAHs) and its influence on the sorption equilibrium is indicative of sorption energies and mechanisms. In this study, sorptions of five PAHs on three heterogeneous sorbents including one river sediment (YHR), one estuary sediment (YRD) and one treated sediment with organic matter removed (IM) were carried out at a range of temperature from 5 °C to 35 °C. Stronger sorptions were observed at lower temperatures, with the equilibrium sorption coefficient K_d increasing 2-5 times as the temperature decreases 30 °C. The increase of K_d value was attributed primarily to the change of PAH water solubility, which predicted 40-75% of the increase of K_d in the sorption process. To provide insight into the sorption mechanism, enthalpy change (ΔH_S) for the sorption process was calculated and the values were observed to be negative for all of the interactions, suggesting that the exothermal sorption of PAHs inversely dependents on temperature. Based on the values of ΔH_S, van der Waals forces were inferred as the main sorption mechanism for the PAHs, especially on the YHR sediment which contained more organic matter. For sorption of larger size PAHs on the sorbents with low organic matter, specific interactions were deduced to contribute to the overall sorption.     

MBR工艺中溶解性有机物的分子量和EEM解析

采用凝胶过滤色谱(GFC)分子量测定技术和三维荧光(EEM)光谱技术,对平板膜-生物反应器工艺应用于餐饮废水和粪便污水处理的工程实例进行研究,对比分析2套工艺中的调节池水和出水的溶解性有机物(DOM)及污泥胞外聚合物(EPS)的性质变化.研究表明,餐饮废水处理过程的调节池水DOM中大分子(＞100 kDa)物质比例为6...     

水力条件对复合人工湿地处理城市受污染河水效果的影响

通过对水力负荷、水力停留时间等水力条件的控制,观察其对复合垂直上行流人工湿地处理城市受污染河水效果的影响.一年多来的运行结果表明:水力条件对复合垂直上行流人工湿地去除其他污染物的影响显著,但对总氮去除的影响不大.水力停留时间的延长可提高总磷、氨氮、COD的去除效果;随着水力负荷的增加,总磷、氨氮、COD去除率都有所增加...     

固定化微生物法去除模拟渗滤液中氨氮的研究

采用固定化微生物曝气生物滤池（I-BAF）技术成功处理了模拟垃圾渗滤液,探讨了pH和溶解氧（DO）对系统脱氮性能的影响。结果表明,固定化微生物曝气生物滤池反应系统启动迅速,运行稳定,可以有效去除模拟垃圾渗滤液中的有机物和氨氮,其去除率分别达到97.1%和99.9%。在pH为7.5～8.5之间,DO 4.0 mg/L左右的条件下对模拟垃圾渗滤液中氮的去除最为有利,同步硝化反硝化效率以及总氮去除率均达到最高,分别为96.2%和94.3%。这主要是由于I-BAF系统中大孔载体提供了厌氧-兼氧-好氧的微环境,使硝化和反硝化反应在同一个反应器内发生,共同作用实现模拟垃圾渗滤液中总氮的去除。     

PVA降解混合菌系生长和产酶的营养条件分析

研究碳源、氮源以及不同金属离子对PVA降解混合菌系生长和产酶的影响。结果表明,混合菌系生长过程中无机氮源优于有机氮源;补充碳源可促进混合菌系的生长,但酶活比不添加时稍有降低。金属离子对酶活影响的正交实验表明Mg2＋浓度影响最大,其次是Fe2＋和K＋浓度,Ca2＋、Mn2＋、Zn2＋和Cu2＋浓度影响较小;最佳浓度分别为Mg2＋0.05 g/L、Fe2＋0.04 g/L、K＋2 g/L和Ca2＋0.05 g/L。     

Distribution characteristics of organochlorine pesticides in surface and vertical sediments from the Zha Long Wetland, China

Introduction

The Zha Long Wetland, the first water bird conservation area in China, lies on the northern bank of the Song Nen Plain with an area of 2,100 km². In many areas of the Zha Long Wetland, water pollution has led to a decrease in the wetland??s ecological function, vegetation degradation, a decrease in the number of bird species, and the depletion of fish resources.

Materials and methods

The sediments used in this study were collected from the surface sediment of seven sites and from different depths in three types of marshes in the Zha Long Wetland in northeast China in late October 2006. The levels and distribution patterns of 17 organochlorine pesticides (OCPs; ??-HCH, ??-HCH, ??-HCH, ??-HCH, p,p??-DDE, p,p??-DDD, p,p??-DDT, endosulfan I, endosulfan II, endosulfan sulfate, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, endrin aldehyde, and methoxychlor) in surface sediments as well as hexachlorocyclohexane (HCH) and 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) in vertical sediments were investigated.

Results and discussion

The concentrations of HCHs, DDTs, endosulfans, heptachlors, aldrin, and methoxychlor in surface sediments ranged from 10.44 to 41.97 ng/g, nd (undetectable levels) to 211.88 ng/g, nd to 69.89 ng/g, nd to 28.10 ng/g, 9.81 to 623.83 ng/g, and from nd to 3.99 ng/g, respectively. The highest levels of OCPs were detected in Tangtugangzi at a total concentration of 727.72 ng/g, where the dominant compound was endrin at a concentration of 483.04 ng/g. In the vertical sediments, the HCHs and DDTs were in the ranges of nd?C136.00 and nd?C214.06 ng/g, respectively.

Conclusions

Different distributions of HCHs, DDTs, and other OCPs indicated that they originated from different contamination sources. Composition analyses in surface sediments indicated recent OCP usage or discharge at some sample sites in the Zha Long Wetland.     

磷酸铵镁碱促(Mg(OH)_2)热解产物氨氮去除性能

磷酸铵镁热解循环技术可以有效降低磷酸铵镁结晶技术的药剂费用。同时,在磷酸铵镁热解过程中添加Mg(OH)2碱促媒介,能阻止磷酸氢镁向焦磷酸镁的转化,并降低热解产物氨氮去除过程中上清液磷酸盐的残留。在Mg(OH)2∶NH+4摩尔比为1∶1,热解温度为110℃条件下,热解产物沉氨效率接近84%,上清液磷酸盐残留量为0.02 mg/L。