title: Hierarchical eco-restoration: a systematical approach to removal of COD and dissolved nutrients from an intensive agricultural area.
abstract: A systematical approach based on hierarchical eco-restoration system for the simultaneous removal of COD and dissolved nutrients was proposed and applied in a complex residential-cropland area in Kunming, China from August 2006 to August 2008, where the self-purifying capacity of the agricultural ecosystem had been lost. The system includes four main parts: (1) fertilizer management and agricultural structure optimization, (2) nutrients reuse, (3) wastewater treatment, and (4) catchment restoration. The results showed that the average removal efficiencies were 90% for COD, 93% for ammonia, 94% for nitrate and 71% for total dissolved phosphorus (TDP) when the hierarchical eco-restoration agricultural system was in a relatively steady-state condition. The emergence of 14 species of macrophytes and 4 species of zoobenthos indicated that the growth conditions for the plankton were improved. The results demonstrated that this promising and environmentally benign hierarchical eco-restoration system could decrease the output of nutrients and reduce downstream eutrophication risk.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 Beijing East Road, Nanjing 210008, PR China. yhwu@issas.ac.cn
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Wu
authors.forename: Zhengyi
authors.initials: Z
authors.lastname: Hu
authors.forename: Linzhang
authors.initials: L
authors.lastname: Yang
mesh_terms: D000383:Agriculture; D000641:Ammonia / Q000032:analysis; D057919:Biological Oxygen Demand Analysis; D017753:Ecosystem; D005618:Fresh Water / Q000737:chemistry; D009566:Nitrates / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis*; D010710:Phosphates / Q000032:analysis; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D009566:Nitrates; D009930:Organic Chemicals; D010710:Phosphates; D012722:Sewage; D014874:Water Pollutants, Chemical; D000641:Ammonia