Review of emerging issues in sediment treatment

Abstract

Sediment treatment options include dredging, physical and chemical capping, and in situ sediment treatment. In our studies, in situ sediment treatment has been used to oxidize sediment sulphides, control eutrophication and bioremediate organic contaminants. Sediment contamination of various types was studied in 22 sites from six countries in North America, Europe and Asia. In Hong Kong, field testing of sediment treatment oxidized 99% of sulphide and controlled odours. In Lake Biwa, Japan, where excess nutrients in sediments enhanced growth of toxin producing algae, sediment treatment with calcium nitrate blocked growth of these algae. Oxidation of sulphide in Lake Biwa sediments precipitated > 80% of the porewater phosphorus. Oxidation of sulphides and addition of nutrients biodegraded more than half of the organic contaminants in Hamilton Harbour, Canada. The biotreatability of polynuclear aromatic hydrocarbons is very site specific and is faster in sites with higher concentrations of oil.

Effectiveness and Mode of Action of Calcium Nitrate and Phoslock® in Phosphorus Control in Contaminated Sediment, a Microcosm Study

“…Sediment dredging is a simple way to remove internal nutrients but the outcomes were found controversial (Jing et al 2013;Liu et al 2015;Zhang et al 2010). In addition, high cost and problems associated with the treatment and disposal of the dredged sediment prevent the wide application of sediment dredging (Murphy et al 1999). In situ treatment, which can considerably reduce the cost and cause less disturbance to the sediment, becomes a more attractive solution.…”

Large-scale utilization of water hyacinth for nutrient removal in Lake Dianchi in China: The effects on the water quality, macrozoobenthos and zooplankton

“…Seriously, bloom cyanobacteria produces toxins, which have been considered responsible for human illnesses (Chorus and Bartram, 1999). Therefore, various strategies to improve water quality have been proposed, such as sediment dredging (Desprez, 2000), sediment curing (Murphy et al, 1999), and macrophyte restoration (Lauridsen et al, 2003). Sediment dredging is not only high cost, but may significantly reduce benthos (Desprez, 2000).…”

“…Sediment curing is often using some chemicals or special materials, which are often associated with changes in salinity or pH. It may risk the life in the lake (Murphy et al, 1999). Also, there were few successful examples about submerged or emerging macrophyte restoration in large lakes.…”

Effects of engineered application of Eichhornia crassipes on the benthic macroinvertebrate diversity in Lake Dianchi, an ultra-eutrophic lake in China

“…Eutrophication can result in serious problems in lakes, such as reduced water quality, decreased biodiversity, induced toxic cyanobacterial bloom, and even though threatened the drinking water safety. Thus, various strategies to control eutrophication in lakes have been proposed, such as control of external nutrient loading, sediment dredging, sediment curing, and phytoremediation (Murphy et al 1999;Desprez 2000;Ye et al 2011). Among these, phytoremediation is very attractive and widely used because of its low cost and easy management (Sun et al 2009).…”