金山湖底泥重金属稳定化处理效果及机制研究

采用氧化钙和过氧化钙及二者混合物对底泥中的重金属进行稳定化试验,研究了稳定化后底泥中重金属迁移情况,并对底泥重金属稳定化技术的机制进行初步探讨.酸雨淋溶试验结果表明,底泥经CaO、CaO CaO2、CaO2稳定化后, pH=2.9时, Zn迁移到第3层,其首层迁移量分别为96、97和93mg/kg,而空白试验中Zn迁移至第6层,首层迁移量为128mg/kg; pH:5.0时, Zn迁移到第3层,其首层迁移量分别为87、90和89mg/kg,而空白试验中Zn迁移至第5层,首层迁移量为112mg/kg,这说明稳定化底泥中Zn的迁移速度和首层迁移量均有降低,3种稳定化药剂能够降低其在土壤中的迁移能力;淋溶液pH值对Zn的迁移能力有影响, pH较高能够减缓Zn在土壤中的迁移速度,降低其首层迁移量; Ni和Cd的酸雨淋溶试验也可得出同样结论.重金属稳定化机制试验结果表明,经上述3种药剂稳定化处理后,底泥pH值由6.76分别上升到8.33、8.15和8.21, TOC含量分别降低5%、10.9%和13.1%; Zn、Ni和Cd的稳定态含量分别增加10.6%、1.7%和4.5%,这是导致重金属迁移能力下降的主要原因;由此可见,3种药剂对同一金属的稳定化作用无明显差异;从不稳定态向稳定态转化的比例来看,稳定化药剂对不稳定态金属的稳定能力次序为: Zn>Cd>Ni.     

二次富集气相色谱法测定环境中的痕量磷化氢

本文研究了富集柱类型、富集温度和色谱操作条件等因素对二次富集气相色谱法测定环境中痕量PH3的影响,并将其应用于青岛大气和东海陆架沉积物中PH3的测定,取得了较为满意的结果.该方法具有操作简单、灵敏度高、分析速度快、干扰少等优点,其检测限为0.02 pg、精密度2.0%、线性范围为0.56 pg～5.6 ng.用此方法测定了冬季东海大陆架表层沉积物中PH3含量为(0.51～23.10)×10-9,其分布明显受到人类活动的影响,研究结果还表明东海沉积物中的PH3是海洋中磷的潜在来源之一;青岛崂山大气中PH3日变化趋势说明大气中PH3明显受光照的影响.     

施用牛粪肥和复混肥对碳酸盐岩试片溶蚀作用影响的室内模拟研究

农业施肥影响土壤的理化性质,影响土壤碳酸盐风化动力学,以至影响碳循环系统。本研究通过土柱模拟试验,结合底部埋置碳酸盐岩试片,依据淋滤液的水化学对比分析,研究了施用牛粪肥及复混肥对土下碳酸盐岩试片溶蚀作用的影响。结果表明,施用牛粪肥后,淋滤液中的HCO-3、C1^～、NH4＋、耗氧量（COD）、K＋、Ca2＋、Mg＋、N...     

基于卫星遥感的广东地区对流层二氧化碳时空变化特征

利用瓦里关全球本底站和番禺气象局地面观测的CO2浓度资料对SCIAMACHY反演得到的对流层CO2产品进行验证.结果显示:SCIAMACHY产品能较好地反映对流层CO2的分布状况,在珠三角地区反演和观测的残差为1.29×10-6,相关系数为0.69,可用于分析区域对流层CO2的时空分布特征.利用2003~2009年SCIAMACHY观测资料分析研究显示:广东地区对流层CO2柱浓度最高值出现在春季,最低值出现在夏季,浓度年均值和年增长率分别为384.84′10-6和1.53′10-6/a,大于全球和我国同期的观测结果;粤东、粤西、粤北和珠三角地区的浓度均在春、冬季显著高于夏季、秋季 ,相同季节内各区域之间的差异不显著;粤西地区CO2柱浓度的年增长率最高,为1.82′10-6/a,珠三角和粤东地区的年增长率相当,分别为1.65,1.64′10-6/a,粤北地区的年增长率最低,为1.61′10-6/a.     

Al13形态的凝胶层析分离及分离级分特性对比

采用聚丙烯酰胺凝胶柱层析法分离纯化聚合氯化铝(PAC)中的Al₁₃形态,并采用Al- Ferron逐时络合比色法、透射电镜(TEM)和ZATESIZER测定仪对分离纯化过程中所得3个级分进行了分析表征和电荷特性的研究;采用烧杯实验法对3个级分处理实际和模拟水样的混凝效果进行了对比性研究.Al- Ferron逐时络合比色法和TEM结果表明,在层析法分离中级分随着洗脱时间延长按分子的大小依次洗脱下来,因此截取中间组分即可得到含量95 %左右的纳米Al₁₃形态;电荷特性和混凝效果研究结果表明,第3个级分其他两者具有更好的除浊、除腐殖酸和脱色效果,并且具有更强的电中和能力,因此Al₁₃形态是一种具有较高正电荷和较高的水解稳定性以及宽的pH适用范围,在给水和废水处理中是一种较为有效的Al形态.     

贵州高原红枫湖水库季节性分层的水环境质量响应

为了揭示贵州高原深水水库水体的垂直分层结构及其水环境质量响应特征,于2008年8月~2009年10月对红枫湖水库5个采样点进行了45次采样,对水文、营养盐等湖沼学变量季节动态和分布进行了分析,探讨了季节性水质恶化事件的发生机制.结果表明,红枫湖水库水体呈单循环混合模式,在4~9月形成分层,但没有典型分层湖泊的温跃层变化,这种不显著的分层导致了水化学的分层.叶绿素a、总磷、总氮和氨氮平均值分别为13.6mg/m3,0.063mg/L,1.22mg/L,0.347mg/L;透明度为1.9m.指示该水库处于中-富营养状态.分层期底层溶解氧在0.3~6.9mg/L之间、平均为2.6mg/L,氮磷质量比在8~104之间,表明红枫湖水库是一个底层滞留带季节性缺氧的高氮、磷限制型水库.贵州高原深水水库季节性水质恶化事件与水体分层结构失稳有关,是富营养化水库在气温骤降时发生“翻湖”所导致的结果,也是贵州高原深水水库富营养化的另一种表现形式.     

Removal of congo red and basic violet 1 by chir pine (Pinus roxburghii) sawdust,a saw mill waste: batch and column studies

The efficiency of chir pine sawdust (CPS) for adsorptive removal of the dyes, congo red (CR) and basic violet 1 (BV), from aqueous solution was evaluated using batch and column studies. The equilibrium was attained in 60 min for CR and 45 min for BV. The adsorption of BV obeyed the Langmuir isotherm model while the Freundlich isotherm fitted the equilibrium data of CR adsorption. The Langmuir monolayer adsorption capacities (Q_o) of CPS for BV and CR were 11.3 and 5.8 g kg^?1, respectively. The kinetic data for CR were best fitted to the Lagergren pseudo-first-order model and for BV to the pseudo-second-order model. The intra-particle diffusion was found to be the rate-controlling step for CR adsorption, while the adsorption kinetics of BV were controlled by both intra-particle and liquid-film diffusion. The thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic in nature. The adsorption activation energy (E_a) for CR (124 kJ mol^?1) implied chemical adsorption while that for BV (5.4 kJ mol^?1) indicated physical adsorption. An increase in the Thomas model constant (K_Th) with increasing flow indicated that for both dyes the mass transport resistance decreased during adsorption. Thus, CPS may be an efficient low-cost adsorbent for decolorization of dye-containing wastewaters.     

It's a dirty job but someone has to do it: The role of marine benthic macrofauna in organic matter turnover and nutrient recycling to the water column

Benthic macrofaunal populations through their feeding, bioturbation, burrow construction and sediment irrigation activities have profound influences on organic matter inputs to marine sediments (biodeposition) and on the vertical distribution of deposited organic matter within the sediment. These effects in turn influence the rates and pathways of organic matter mineralisation, and element cycles. Similarly, bioturbation, burrow construction and burrow irrigation are major determinants of sediment-water column fluxes of oxygen and nutrients.

In this review, I discuss the influences of the different benthic macrofaunal feeding (functional) groups on mineralisation processes and sediment-water column fluxes of particulate and dissolved nutrients. How these effects influence diagenic processes, the balance between aerobic and anaerobic processes, and the redox status of the surficial sediments. Finally, I discuss some of the limitations of the predominantly laboratory techniques which have been used to study “macrofaunal effects” and how this hinders the inclusion of the effects in quantitative sediment biogeochemical models.     

Transport of Sewage Sludge in a Mixed Water Column

Abstract

Sewage sludge from four publicly-owned treatment works was sampled and characterized in terms of parameters affecting transport at the 106-mile deep ocean disposal site as part of the US Environmental Protection Agency's site monitoring programme. Samples from treatment plants in Passaic Valley, Rahway, and Elizabeth, New Jersey and New York City were characterized in terms of dynamic size distribution, suspended solids and density. the transport characteristics of sludge particles were measured using a 2 metre computer-interfaced laboratory settling column. Experiments were conducted at constant salinity (35 ppt) while varying hydrodynamic mixing, sludge type and concentration using a modified factorial experimental design. Hydrodynamic power dissipation was varied so that the vertical dispersion and rms fluid shear rate ranged between 0-6 cm²S^?1 and 0-30s^?1 respectively. Results indicate that at least 80% of suspended sludge particles will eventually settle under mixed conditions. the average settling velocities ranged between 0.05-4.05 × 10^-3 cm ^s-1. Shear rates above 15 s^?1 inhibited sludge settling due to aggregate breakup and boundary effects, but at a lower shear rate, differential settling and fluid shear were the dominant transport mechanisms. Sludge dilution (1/500-1/5000) had a limited effect on the settling rate. Results from this study can be used to calibrate particle transport models to determine the fate of sludge disposed at an ocean disposal site.     

Spatial distribution of copper in relation to recreational boating in a California shallow-water basin

The overall effect of the number of boats on the copper (Cu) levels in the water column and sediment, along with their spatial variability within Shelter Island Yacht Basin (SIYB), San Diego Bay, California was examined. We identified a horizontal gradient of increasing dissolved Cu and Cu in sediment from outside to the head of SIYB which was coincident with the increasing number of boats. Spatial models of Cu distribution in water and sediment indicated the presence of ‘hotspots’ of Cu concentration. From outside to the head of SIYB, dissolved Cu ranged from 1.3 μ g L^?1 to 14.6 μ g L^?1 in surface water, and 2.0 μ g L^?1 to 10.2 μ g L^?1 in bottom water. Cu in sediment exceeded the Effect Range Low of 34 mg kg^?1 (i.e. where adverse effects to fauna may occur), with a peak concentration of 442 mg kg^?1 at the head of the basin. Free Cu⁺⁺ in surface water was several orders of magnitude higher than in sediment porewater. High-resolution data of Cu species together with probability maps presented in this paper will allow managers to easily visualise and localise areas of impaired quality and to prioritise which areas should be targeted to improve Cu-related conditions.