基于优质碳源提供的CAMBR复合工艺短程硝化-反硝化除磷研究

挥发性脂肪酸(VFA)是反硝化除磷过程可以利用的优质碳源,为此本研究结合厌氧折流板反应器(ABR)微生物相分离和膜生物反应器(MBR)出水水质优良的特性,构建了CAMBR复合工艺,并通过优化ABR水力停留时间(HRT)等运行条件以提供优质碳源,实现高效反硝化除磷.研究表明,当ABR的HRT为4.8 h时,可获得充足的VFA作为优质碳源,并实现消耗VFA的量为56.1 mg·L~(-1)的同时获得10.43 mg·L~(-1)的释磷,即释放1 mg磷需要的VFA量为5.38 mg,同时实现12.35 mg·L~(-1)的吸磷,而MBR池的吸磷为1.33 mg·L~(-1).短程硝化除磷过程中,缺氧消耗1 mg PO_4~(3-)-P需要0.62 mg的NO-x-N,吸收1 mg PO_4~(3-)-P所需NO_2~--N的量为1.67~2.04 mg.系统出水水质稳定,COD、TN和溶解性PO_4~(3-)-P的平均去除率分别为91%、84%和93%,出水平均浓度分别为30、7.15和0.55 mg·L~(-1),表明CAMBR复合工艺生在处理生活污水过程中可获得稳定高效的反硝化除磷效果.     

碱性过硫酸钾氧化-紫外分光光度法测水体总氮

碱性过硫酸钾氧化--紫外分光光度法所用消化剂K2S2O8在220nm处有很强的吸收峰，在消解过程中应确保其分解完全，否则即使其只有总量1%的残余，仍足以构成对比色测定的严重干扰。NaOH溶液在220nm处也有吸光度，但加盐酸中和后即减弱。消煮液的残余碱度对比色的干扰也可以同法消除。     

Plant uptake and dissipation of PBDEs in the soils of electronic waste recycling sites

Plant uptake and dissipation of weathered PBDEs in the soils of e-waste recycling sites were investigated in a greenhouse study. Eighteen PBDE congeners (tri- through deca-) were detected in the plant tissues. The proportion of lower brominated PBDEs (mono- through hexa-) in plant roots was higher than that in the soils. A concentration gradient was observed of PBDEs in plants with the highest concentrations in the roots followed by the stems and lowest in the leaves. Reduction rates of the total PBDEs in the soils ranged from 13.3 to 21.7% after plant harvest and lower brominated PBDEs were associated with a higher tendency to dissipate than the higher brominated PBDEs. This study provides the first evidence for plant uptake of weathered PBDEs in the soils of e-waste recycling sites and planting contributes to the removal of PBDEs in e-waste contaminated soils.     

实际污水与模拟污水活性污泥系统的特性差异

实验中经常采用人工配置的模拟生活污水,为了研究其与实际生活污水活性污泥系统的特性差异,采用2个序批式间歇反应器(SBR)进行平行实验(厌氧、好氧方式运行),系统地考察了在进水主要组分和运行参数相同的情况下,不同原水对活性污泥系统脱氮、除磷、比好氧速率、污泥絮体形态和出水水质等方面的影响。结果表明,模拟污水系统的硝化活性强于实际污水系统,两者的平均硝化速率分别为7.43 mg NH4+-N/(L.h)和5.55 mg NH4+-N/(L.h)。在前置厌氧段,模拟污水系统的释磷量比实际污水系统高出36.45%。两者在后续好氧阶段都能够充分吸磷。模拟污水系统的平均比好氧速率(SOUR)高达64.54 mg O2/(g MLSS.h),而实际污水系统的则只有32.81 mg O2/(g MLSS.h)。模拟污水系统的污泥絮体疏松,粒径小,形状不规则,沉降性差,沉后出水平均悬浮物浓度(SS)为20 mg/L;而实际污水系统的污泥絮体则密实、粒径大,沉降性好,沉后水十分清澈,SS几乎检测不出。     

Phosphorus accumulation by bacteria isolated from a ontinuous-flow two-sludge system

In this article, polyphosphate-accumulating organisms （PAOs） from a lab-scale continuous-flow two-sludge system was isolated and identified, the different phosphorus accumulation characteristics of the isolates under anoxic and aerobic conditions were investigated. Two kinds of PAOs were both found in the anoxic zones of the two-sludge system, one of them utilized only oxygen as electron aeceptor, and the other one utilized either nitrate or oxygen as electron aeceptor. Of the total eight isolates, five isolates were capable of utilizing both nitrate and oxygen as electron acceptors to uptake phosphorus to some extent. And three of the five isolates showed good phosphorus accumulative capacities both under anoxic or aerobic conditions, two identified as Alcaligenes and one identified as Pseudomonas. Streptococcus was observed weak anoxic phosphorus accumulation because of its weak denitrification capacity, but it showed good phosphorus accumulation capacity under aerobic conditions. One isolates identified as Enterobacteriaceae was proved to be a special species of PAOs, which could only uptake small amounts of phosphorus under anoxic conditions, although its denitrification capacity and aerobic phosphorus accumulation capacity were excellent.     

Immobilization of activated sludge using improved polyvinyl alcohol （PVA） gel

The microbial immobilization method using polyvinyl alcohol(PVA)gel as an immobilizing material was improved and used for entrapment of activated sludge.The oxygen uptake rate(OUR)was used to characterize the biological activity of immobilized activated sludge.Three kinds of PVA-immobilized particles of activated sludge,that is,PVA-boric acid beads,PVA-sodium nitrate beads and PVA-orthophosphate beads were prepared,and their biological activity was compared by measuring the OUR value.The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media (containing 250 mg/L COD and 25 mg/L NH_4~ -N).The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation.With respect of the bioactivity and the mechanical stability,the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization.     

基于QUAL2K模型的鹤壁卫河水质模拟预警研究

水质预报预警对于防范水污染、降低水污染风险及其带来的损失、保障用水安全及水环境质量等具有重大意义。提出了一种基于QUAL2K模型的水质模拟预警方法,包括水质模拟预测、预警指数计算和警情确定,以海河流域鹤壁市卫河为例进行实证研究。研究结果表明:基于QUAL2K模型模拟精度分别为COD 97.7%、NH_3-N 98.5%,水质模拟效果较好;所选河段预警时段内COD基本处于无警和轻警2个级别,氨氮大多是巨警,浓度严重超标,是导致监测断面预警指数高的主要原因。