Modeling Nutrient Transports and Exchanges of Nutrients Between Shallow Regions and the Open Baltic Sea in Present and Future Climate

We quantified horizontal transport patterns and the net exchange of nutrients between shallow regions and the open sea in the Baltic proper. A coupled biogeochemical-physical circulation model was used for transient simulations 1961-2100. The model was driven by regional downscaling of the IPCC climate change scenario A1B from two global General Circulation Models in combination with two nutrient load scenarios. Modeled nutrient transports followed mainly the large-scale internal water circulation and showed only small circulation changes in the future projections. The internal nutrient cycling and exchanges between shallow and deeper waters became intensified, and the internal removal of phosphorus became weaker in the warmer future climate. These effects counteracted the impact from nutrient load reductions according to the Baltic Sea Action Plan. The net effect of climate change and nutrient reductions was an increased net import of dissolved inorganic phosphorus to shallow areas in the Baltic proper.     

Influence of dissolved humic substances on the mass transfer of organic compounds across the air-water interface

The effect of dissolved humic substances (DHS) on the rate of water-gas exchange of two volatile organic compounds was studied under various conditions of agitation intensity, solution pH and ionic strength. Mass-transfer coefficients were determined from the rate of depletion of model compounds from an apparatus containing a stirred aqueous solution with continuous purging of the headspace above the solution (dynamic system). Under these conditions, the overall transfer rate is controlled by the mass-transfer resistance on the water side of the water-gas interface. The experimental results show that the presence of DHS hinders the transport of the organic molecules from the water into the gas phase under all investigated conditions. Mass-transfer coefficients were significantly reduced even by low, environmentally relevant concentrations of DHS. The retardation effect increased with increasing DHS concentration. The magnitude of the retardation effect on water-gas exchange was compared for Suwannee River fulvic and humic acids, a commercially available leonardite humic acid and two synthetic surfactants. The observed results are in accordance with the concept of hydrodynamic effects. Surface pressure forces due to surface film formation change the hydrodynamic characteristics of water motion at the water-air interface and thus impede surface renewal.     

硅藻土强化混凝去除微污染原水中的有机物

研究了联用硅藻土与聚合氯化铝（PAC）强化混凝对有机微污染原水中不同性质溶解性有机物的去除效果。采用超滤膜和XAD系列树脂对微污染原水中溶解性有机物进行分级表征,物理分级表明分子量〈4 kD的溶解性有机物占50%以上,化学分级表明原水中以憎水酸（HoA）和亲水物质（HiM）为主。硅藻土助凝去除溶解性有机物,实验结果表明,当PAC投加量30 mg/L,硅藻土投加量0.5 g/L时,溶解性有机碳去除率由22.5%提高到26.3%。     

铁盐和铝盐混凝对印染废水生化出水中溶解性有机污染物的去除特性

以三氯化铁和硫酸铝为混凝剂,印染废水二级生化出水为研究对象,并利用XAD-8/XAD-4吸附树脂联用技术将印染废水生化出水中溶解性有机物分为疏水酸、非酸疏水物质、弱疏水物质及亲水物质4类有机物,通过小试实验探讨了2种混凝剂对生化出水中各类溶解性有机物的去除效果及特点。实验结果表明,对于该印染废水的生化出水,溶解性有机物的主要成分是疏水性物质,以DOC表征时占总DOC的75%,其中疏水酸约占41%,疏水性物质也是引起色度的主要物质,所占比例以ADMI7.6表征时为89%,其中以非酸疏水物质的贡献最大,达到52%,并且非酸疏水物质中不饱和双键或芳香环有机物的含量较高。在三氯化铁和硫酸铝各自最佳的混凝条件下,均能够有效去除由疏水性物质（疏水酸和非酸疏水物质）引起的色度,但三氯化铁对弱疏水性物质以及亲水物质的去除率高于硫酸铝,这使得三氯化铁对印染废水生化出水中的溶解性有机物的去除效果优于硫酸铝。并且三氯化铁和硫酸铝混凝工艺均能明显降低生化出水的毒性。     

The effect of greenhouse vegetation coverage and area on the performance of an earth-to-air heat exchanger for heating and cooling modes

The underground temperature at a depth of about 3–4 m is almost constant all the year round. In summer, the underground temperature is lower than the ambient temperature, but in winter it is vice versa. This potentiality is considered for greenhouse cooling and heating by using an earth-to-air heat exchanger (EAHE). This paper considers the effects of two parameters as independent variables including the area of greenhouse and the percentage of vegetation coverage inside the greenhouse on the performance of an EAHE system during both cooling and heating modes. The inside temperature, the thermal energy exchange and the coefficient of performance (COP) of the system were considered as dependent variables. The results showed that both greenhouse area and the percentage of vegetation coverage inside the greenhouse had significant effects on the performance of the EAHE system during both cooling and heating modes. However, the COP of the EAHE system was higher in the cooling mode (4.32) than during the heating mode (1.01). The percentage of vegetation coverage negatively affected the performance of the EAHE system in the cooling mode. However, the performance of the EAHE system improved with the increase in the percentage of vegetation coverage during the heating mode.     

树脂法去除并回收富营养化河涌水中的磷

磷作为一种重要的元素而被广泛应用于农业与工业中,然而磷的过量排放已成为许多封闭半封闭水体富营养化和沿海赤潮频繁发生的原因之一.去除水体中的营养盐特别是磷酸盐,是有效控制水体富营养化的关键.广州市某河涌水含总磷2.6 mg/L,采用并选择DS离子交换树脂对水中磷进行动态吸附和去除,可使水中的磷降至排放标准以内,解决河涌水含磷高的富营养化问题.由DS树脂所吸附的磷,通过淋洗可得到含磷富集液,使磷从水体中完全分离出来并获得回收.DS树脂的再生能力强,经6次吸附-解吸-再生后,树脂对河涌水中磷的去除率仍可达到90％以上.     

HZ-16型大孔树脂吸附处理含RDT-8废水

采用HZ-16型大孔树脂对含三（三溴苯氧基）三嗪（RDT-8）废水进行吸附及脱附处理。实验结果表明：在废水流量为4.0 BV/h的条件下,树脂最佳吸附工艺条件为出水体积88.0 BV,此条件下出水COD小于291 mg/L,挥发酚质量浓度小于0.08 mg/L;在脱附液流量为0.5 BV/h的条件下,树脂最佳脱附工艺条件为脱附液体积3.0 BV,此条件下脱附液中挥发酚质量浓度为30.6 mg/L,挥发酚脱附率高达76.4%。在最佳吸附-脱附工艺条件下,连续进行10次动态吸附-脱附实验,吸附出水中COD为137~294 mg/L,COD去除率为72.5%~89.1%,挥发酚质量浓度稳定在0.05 mg/L以下,挥发酚去除率为99.8%~100%,说明HZ-16型大孔树脂的吸附-脱附性能稳定。     

螯合树脂去除丙烯酸丁酯废水中的二价阳离子

采用氨基膦酸螯合树脂C-900去除丙烯酸丁酯废水中的二价阳离子,考察了吸附温度和废水流量对树脂动态吸附性能的影响,并用Thomas模型进行动态吸附数据的拟合分析。实验结果表明,在吸附温度为35℃、废水流量为15SV的条件下,处理后出水中3种二价阳离子总质量浓度为1.0mg/L时的穿透体积为240BV,达到穿透体积时树脂对Ca²⁺,Mg²⁺,Cu²⁺的去除率分别为100%,99.2%,99.8%。     

NaCl改性沸石去除水中低浓度铅的研究

实验研究了NaCl改性沸石去除水中铅的效果,比较了沸石改性前后对铅的静态平衡吸附量变化,着重考察了吸附时间、pH值、竞争离子以及有机物对去除铅效果的影响。结果表明:NaCl改性沸石吸附铅速度快,对铅有很好的去除效果,平衡吸附量由改性前的28.57mg/g提高到了32.26mg/g。pH值对NaCl改性沸石去除水中铅的效果有较大影响,在pH=6～7时,去除效果最佳。水中竞争阳离子和有机物的存在,在一定程度上会降低铅的去除效果;随干扰物质浓度的升高,NaCl改性沸石对铅去除率出现了明显的下降,但当干扰物质和水样中铅浓度相当时,NaCl改性沸石可对铅保持很高的去除率。     

黑龙江省东部煤电化基地经济与生态环境协调发展评价研究

构建东部煤电化基地是继哈大齐工业走廊启动建设后,黑龙江省做出的一项重大战略部署。基地建设要求深入贯彻科学发展观,大力发展煤化工产业,实现全面、协调、可持续发展。全面协调发展不仅是经济的发展,同时也要考虑生态环境的保护。运用层次分析法和协调发展度模型,研究黑龙江东部煤电化基地经济和生态环境的协调发展程度表明,黑龙江东部煤电化基地经济和生态环境协调发展水平处于中等协调状况。针对评价结果,提出了相应的对策和建议。