Impacts of aquatic macrophytes configuration modes on water quality

Abstract

Constructed wetland technology is regarded as an important ecological restoration technology and used widely in sewage disposal. In order to give them a wider scope of application and to improve their performance in water restoration, the current experiment was designed. Four aquatic macrophytes (dwarf cattail (TM), yellow-flowered iris (WI), water shallot (ST) and watermifoil (MS)) were picked and planted in artificial floating islands (AFIs) in different configurations (TM + WI, ST + MS and TM + WI + MS) and two patterns, radiation pattern (RP) and annular pattern (AP), for a 60-day experiment. Then, water quality and growth were monitored every 10 days. The results indicate that the different configurations performed diversely on waste water purification. First, a composite plant configuration removed more pollutant than a single one with the same total increment of biomass. Second, the plant configuration of MS + ST was most effective in total nitrogen (TN), total phosphorus (TP) or PO4(3-) removal, and TM + IW + MS was good at chemical oxygen demand (COD) and NO3(-) removal. However, different patterns comprised from the same species had a certain effect on absorption of pollutants. Generally speaking, plant configurations with a RP were better than an AP in purification. Accordingly, these provided the methods for the pollution wetland restoration.

Ecological Restoration of Habitats Based on Avian Diversity and Landscape Patterns—A Case Study of Haining Mining Pit Park in Zhejiang, China

“…Inside the floating island, we suggest selecting water-resistant shrubs and deciduous trees, we suggest planting Chinese cork oak (Quercus acutissima Carruth), burning bush (Euonymus maackii Rupr), golden rain tree (Koelreuteria paniculata), and Amur honeysuckle (Lonicera maackii) to provide hiding spots for birds [47]. The green area distribution for these three types of plants is 25%, 45%, and 30%, respectively [42,48] (Figure 5). (3) Planting Scheme for Restoration-Oriented Floating Island…”

“…According to the role of plants in supporting birds, their adaptability to the environment, and their impact on the surroundings, a selection of herbaceous wetland plants, aquatic plants, water-resistant shrubs, and deciduous trees was made [2,[47][48][49]. Their roles for birds were categorized into providing food, concealment, and habitat; their adaptability to the environment was assessed in terms of cold resistance and water toler- (3) Planting Scheme for Restoration-Oriented Floating Island According to the role of plants in supporting birds, their adaptability to the environment, and their impact on the surroundings, a selection of herbaceous wetland plants, aquatic plants, water-resistant shrubs, and deciduous trees was made [2,[47][48][49]. Their roles for birds were categorized into providing food, concealment, and habitat; their adaptability to the environment was assessed in terms of cold resistance and water tolerance; and their environmental impact was considered in terms of nutrient control in water and counteracting water alkalization [46].…”

“…The plant selection is divided into inner and outer circles. For the inner circle, species such as sweet flag (Acorus calamus L.) and bulrush (Scirpus validus Vahl) were chosen, constituting approximately 37% of the entire floating island, to improve water nutrient levels [42,48]. The outer circle includes plants like oriental cattail (Typha orientalis Presl) and nutgrass (Cyperus rotundus L.), also making up about 37% of the entire floating island, to mitigate water alkalization [42,48,49] (Figure 3).…”

“…Secondly, habitat-type floating islands are established in the core experimental area for bird conservation to provide a suitable habitat for bird growth and development. Outside the bird conservation area, restorationtype floating islands can be established, and around these islands, plants like rrowhead (Sagittaria sagittifolia) and lotus (Nelumbo SP) can be grown, while snails and clams can be introduced to purify the water [48]. Concurrently, mechanisms for bird protection from natural predators are implemented, such as constructing complex nesting structures to safeguard the young birds and prohibiting bird hunting.…”

Influence of Sediment, Plants, and Microorganisms on Nitrogen Removal in Farmland Drainage Ditches

“…The current understanding of the mechanism of nitrogen transport and transformation by plants is mainly achieved through in situ monitoring experiments, such as the screening and planting of aquatic plants [15,16]. Studies on microbial purification mechanisms are mostly conducted through nitrification and denitrification mechanisms, as well as the addition of microbial strains.…”