Vijayaraghavan K, Joshi Umid Man, Ping Han, Reuben Sheela, Burger David F
a Singapore-Delft Water Alliance , National University of Singapore , Singapore.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2014;49(10):1176-86. doi: 10.1080/10934529.2014.897535.
In this study, in situ hybrid sand filters were designed to remove dissolved and suspended contaminants from eutrophic pond. Currently, there are no attempts made to eradicate dissolved as well as suspended contaminants from eutrophic water system in a single step. Monitoring studies revealed that examined pond contain high chlorophyll-a content (101.8 μg L(-1)), turbidity (39.5 NTU) and total dissolved solids concentration (0.04 g L(-1)). Samples were further exposed to extensive water quality analysis, which include examining physicochemical parameters (pH, conductivity, total dissolved solids, salinity, turbidity and chlorophyll-a), metals (Na, K, Ca, Mg, Al, Fe, Cu, Cd, Pb, Zn, Cr, and Ni) and anions (NO3, NO2, PO4, SO4, Cl, F and Br). To tackle pollutants, filtration system was designed to comprise of several components including fine sand, coarse sand/sorbent mix and gravel from top to bottom loaded in fiberglass tanks. All the filters (activated carbon, Sargassum and zeolite) completely removed algal biomass and showed potential to decrease pH during entire operational period of 20 h at 120 L h(-1). To examine the efficiency of filters in adverse conditions, the pond water was spiked with heavy metals (Cu, Cd, Pb, Zn, Cr, and Ni). Of the different filter systems, Sargassum-loaded filter performed exceedingly well with concentrations of heavy metals never exceeded the Environmental protection agency regulations for freshwater limits during total operational period. The total uptake capacities at the end of the fifth event were 24.9, 20.5, 0.58, 5.2, 0.091 and 2.8 mg/kg for Cr, Ni, Cu, Zn, Cd and Pb, respectively.
在本研究中，设计了原位混合砂滤器以去除富营养化池塘中的溶解污染物和悬浮污染物。目前，尚未有人尝试在一步操作中从富营养化水系统中根除溶解和悬浮污染物。监测研究表明，所检测的池塘中叶绿素-a含量高（101.8μg L⁻¹）、浊度高（39.5 NTU）且总溶解固体浓度高（0.04 g L⁻¹）。对样品进行了进一步的广泛水质分析，包括检测物理化学参数（pH值、电导率、总溶解固体、盐度、浊度和叶绿素-a）、金属（钠、钾、钙、镁、铝、铁、铜、镉、铅、锌、铬和镍）以及阴离子（硝酸根、亚硝酸根、磷酸根、硫酸根、氯离子、氟离子和溴离子）。为了处理污染物，过滤系统设计为由几个组件组成，包括从上到下装入玻璃纤维水箱的细砂、粗砂/吸附剂混合物和砾石。所有过滤器（活性炭、马尾藻和沸石）在120 L h⁻¹的20小时整个运行期间都完全去除了藻类生物量，并显示出降低pH值的潜力。为了检验过滤器在不利条件下的效率，向池塘水中添加了重金属（铜、镉、铅、锌、铬和镍）。在不同的过滤系统中，装有马尾藻的过滤器表现极为出色，在整个运行期间重金属浓度从未超过美国环境保护局规定的淡水限值。在第五次事件结束时，铬、镍、铜、锌、镉和铅的总吸收量分别为24.9、20.5、0.58、5.2、0.091和2.8 mg/kg。
