Carbon và nhu cầu oxy sinh học • DIC carbon vô cơ hòa tan (thường bao gồm cacbonat, CO2, và bicarbonate) • TOC tổng carbon hữu cơ (bao gồm các hình thức giải thể và đình chỉ tất cả) • DOC hòa tan cacbon hữu cơ • NDOC nondissolved carbon hữu cơ • carbon hữu cơ dễ bay hơi VOC (hợp chất) đất hoặc sinh khối , các mẫu bị đốt cháy, giải thể, tiếp theo là phân tích carbon tổng. | Carbon and Biochemical Oxygen Demand Carbon compounds interact strongly with wetland ecosystems. The carbon cycle in wetlands is vigorous and typically provides carbon exports from the wetland to receiving ecosystems. Many internal wetland processes are fueled by carbon imports and by the carbon formed from decomposition processes. Treatment wetlands frequently receive large external supplies of carbon in the added wastewater. Any of several measures of carbon content may be made with biochemical oxygen demand BOD being the most frequent in the treatment of municipal wastewater. Degradable carbon compounds are rapidly utilized in wetland carbon processes. At the same time a variety of wetland decomposition processes produce available carbon. The balance between uptake and production provides the carbon exports. In general the amounts of carbon cycled in the wetland are comparable to the quantities added in domestic wastewater. The growth of wetland plants requires carbon dioxide CO2 for photosynthesis. A variety of organisms release CO2 as a product of respiration. Many pathways lead to the microbial production of CO2 as well as methane CH4 . Both gases dissolve in water to a limited extent so there are active transfers of carbon to and from the atmosphere. In terms of treatment it is therefore not surprising to find good carbon reductions for the added wastewater accompanied by nonzero background levels of various carbon compounds and the related BOD. For purposes of wetland design for BOD removal the challenge is to find relatively simple design tools despite the enormously complex set of wetland functions. WETLAND CARBON SPECIATION AND PROCESSING A wide spectrum of carbon compounds exists in either dissolved or particulate forms in aquatic systems. The usual dividing line is a filter. The following distinctions are made as a result of analytical methods TC total carbon includes all dissolved and suspended forms PC particulate carbon includes organic
