Does Typha spp. Contribute to Wetland Waterloss and Health Risk: A Case Study of Hadejia Nguru Wetlands (HNW) System NE Nigeria

The role of Typha spp. on water loss and public health has been uncertained and relatively poorly reported in Hadejia Nguru wetlands. This study investigated the extent to which Typha spp. contributed to evapotranspirative water loss and the level at which it provides suitable habitat for mosquito breeding. A comparative analysis between Typha swamp and open water was made to determine the evapotranspiration water loss and mosquito larva load accounted for by Typha swamp in the wetland. Maximum and minimum temperatures were measured and recorded daily for the months of January, March and June in 2013. Blaney-Criddle equation was used to estimate the evapotranspiration from Typha swamp (Site A) while piche evaporimeter was used to measure direct evaporation from the adjacent open water (Site B). Water samples were collected in Sites A and B using 100 ml beaker at random and the number of mosquito larvae in the sample was counted. T test was used to evaluate differences in water loss and larva load between open water and Typha swamp in the wetland. The findings revealed that there was no significant difference in water loss at p < 0.05 between Typha swamp and open water in the wetland. However, the Typha swamp was found to harbor more mosquito larvae than the open water at p < 0.05 which was considered a public health risk.

Temporal variability of iron concentrations and fractions in wetland waters in Sanjiang Plain, Northeast China

Chemical forms, reactivities and transformation of iron fractions in marshy waters were investigated with cross-flow filtration technique to study the iron environmental behavior. Iron fractions were divided into four parts： acid-labile iron （pre-acidification of unfiltered marshy water samples, 〉 0.7 μm）, high-molecular-weight iron （0.7-0.05 μm）, medium-molecular-weight iron （0.05-0.01 μm）, and low-molecular-weight iron （〈 0.01μm）. The cross-flow filtration suggested that iron primarily exist in both the 〉 0.7 μm and 〈 0.01 μm size fractions in marshy waters. Rainfall is the key for rain-fed wetland to determine fate of iron by changing the aquatic biochemical conditions. By monitoring the variation of iron concentrations and fractions over three years, it was found that dissolved iron and acid-labile iron concentrations exhibit a large variation extent under different annual rainfalls from 2006 to 2008. The seasonal variation for iron species proved that the surface temperature could control some conversion reactions of iron in marshy waters. Low- molecular-weight iron would convert to acid-labile iron gradually with temperature decreasing. The photochemical reactions of iron fractions, especially low-molecular-weight iron had occurred under solar irradiation. The relative proportion of low-molecular-weight in total dissolved iron ranging from 28.3% to 43.2% were found during the day time, which proved that the observed decreasing concentration of acid lability iron was caused by its degradation to low molecular weight iron.

Microtopographic modification conserves urban wetland water quality by increasing the dissolved oxygen in the wet season

Microtopography affects hydrological processes and forms different microhabitats.Our previous study uncovered that riparian zone microtopography created various microhabitats with different soil environments and runoff-infiltration patterns.However,how riparian microtopography and microtopography within the water area(waterfall and tributary)affects downstream water quality remains unclear.Therefore,water samples were taken almost monthly in both the main stream and the tributary,before and after waterfalls,and near the bottom of three microtopographic types from June 2016 to March 2017.Compared with the dry season,the fact that water quality worsened in the wet season and that there were positive correlations for nitrate(NO3-)between water and the corresponding soil samples suggested that the riparian-soil environment affected the adjacent water quality mainly in the wet season.Nevertheless,riparian microtopography did not influence water quality downstream because of the low rainfall frequency and the weak leaching process due to plant interception.In the wet season,both the tributary and the waterfall increased the dissolved oxygen in the water body and,therefore,lowered the risk of eutrophication.The tributary has two pathways for improving the water quality,by increased disturbance and flow velocity,while the waterfall only has the former.However,such effects were not significant in the dry season.We conclude that the application of microtopographic modification is useful in maintaining urban wetland water quality in wet seasons.

Phytosynthetic bacteria (PSB) as a water quality improvement mechanism in saline-alkali wetland ponds

The efficiency of phytosynthetic bacteria (PSB) to improve the water quality in saline alkali ponds was studied, the result showed that (1) PSB application could increase the content of DO, NO\+-\-3\|N and effective phosphorus (EP) in ponds; (2) the changes of COD were not evident, just effective in later period after PSB application; (3) PSB application could decrease the contents of NH\+-\-4\|N (NH\-3\|N), NO\+-\-2\|N ; (4) PSB application could improve the structure of the effective nitrogen (EN) and EP, stimulate the growth of phytoplankton, and increase primary productivity, and finally increase the commercial profits of ponds because of the increase of EP and the decrease of EN contents; (5) the effect exerting speed of PSB was slower, but the effect sustaining time was longer; (6) the appropriate concentration of PSB application in saline alkali wetland ponds was 10×10 -6 mg/L, one time effective period was more than 15 days. So PSB was an efficient water quality improver in saline alkali ponds.

Distribution characteristics of dissolved organic carbon in annular wetland soil-water solutions through soil profiles in the Sanjiang Plain,Northeast China

Overwhelming evidence reveals that concentrations of dissolved organic carbon （DOC） have increased in streams which brings negative environmental impacts. DOC in stream flow is mainly originated from soil-water solutions of watershed. Wetlands prove to be the most sensitive areas as an important DOC reserve between terrestrial and fluvial biogeosystems. This reported study was focused on the distribution characteristics and the controlling factors of DOC in soil-water solutions of annular wetland, i.e., a dishing wetland and a forest wetland together, in the Sanjiang Plain, Northeast China. The results indicate that DOC concentrations in soilwater solutions decreased and then increased with increasing soil depth in the annular wetland. In the upper soil layers of 0-10 cm and 10-20 cm, DOC concentrations in soil-water solutions linearly increased from edge to center of the annular wetland （R^2 = 0.3122 and R^2 = 0.443）. The distribution variations were intimately linked to DOC production and utilization and DOC transport processes in annular wetland soil-water solutions. The concentrations of total organic carbon （TOC）, total carbon （TC） and Fe（II）, DOC mobility and continuous vertical and lateral flow affectext the distribution variations of DOC in soil-water solutions. The correlation coefficients between DOC concentrations and TOC, TC and Fe（II） were 0.974, 0.813 and 0.753 respectively. These distribution characteristics suggested a systematic response of the distribution variations of DOC in annular wetland soil-water solutions to the geometry of closed depressions on a scale of small catchments. However, the DOC in soil pore water of the annular wetland may be the potential source of DOC to stream flow on watershed scale. These observations also implied the fragmentation of wetland landscape could bring the spatial-temporal variations of DOC distribution and exports, which would bring negative environmental impacts in watersheds of the Sanjiang Plain.

Characteristics of the main inorganic nitrogen accumulation in surface water and groundwater of wetland succession zones

Based on the observation of a complete hydrological year from June 2014 to May 2015, the temporal and spatial variations of the main inorganic nitrogen (MIN, referring to NO3^--N, NO2^--N, NH4^+-N) in surface water and groundwater of the Li River and the Yuan River wetland succession zones are analyzed. The Li River and the Yuan River are located in agricultural and non-agricultural areas, and this study focus on the influence of surface water level and groundwater depth and precipitation on nitrogen pollution. The results show that NO3^--N in surface water accounts for 70%-90% of MIN, but it does not exceed the limit of national drinking water surface water standard. Groundwater is seriously polluted by NH4^+-N.Based on the groundwater quality standard of NH4^+-N, the groundwater quality in the Li River exceeds Class III water standard throughout the year, and the exceeding months' proportion of Yuan River reaches 58.3%. Compared with the Yuan River, MIN in groundwater of the Li River shows significant temporal and spatial variations owing to the influence of agricultural fertilization. The correlation between the concentrations of MIN and surface water level is poor, while the fitting effect of quadratic correlation between NH4^+-N concentration and groundwater depth is the best (R^2=0.9384), NO3^--N is the next (R^2=0.5128), NO2^--N is the worst (R^2=0.2798). The equation of meteoric water line is δD =7.83δ^18O+12.21, indicating that both surface water and groundwater come from atmospheric precipitation. Surface infiltration is the main cause of groundwater NH4^+-N pollution. Rainfall infiltration in non-fertilization seasons reduces groundwater nitrogen pollution, while rainfall leaching farming and fertilization aggravate groundwater nitrogen pollution.

Effects of Anthropogenic Disturbance on Sediment Organic Carbon Mineralization Under Different Water Conditions in Coastal Wetland of a Subtropical Estuary

The changes in soil organic carbon(C) mineralization as affected by anthropogenic disturbance directly determine the role of soils as C source or sink in the global C budget. The objectives of this study were to investigate the effects of anthropogenic disturbance(aquaculture pond, pollutant discharge and agricultural activity) on soil organic C mineralization under different water conditions in the Minjiang River estuary wetland, Southeast China. The results showed that the organic C mineralization in the wetland soils was significantly affected by human disturbance and water conditions(P < 0.001), and the interaction between human disturbance activities and water conditions was also significant(P < 0.01). The C mineralization rate and the cumulative mineralized carbon dioxide-carbon(CO_2-C)(at the 49th day) ranked from highest to lowest as follows: Phragmites australis wetland soil > aquaculture pond sediment > soil near the discharge outlet > rice paddy soil. This indicated that human disturbance inhibited the mineralization of C in soils of the Minjiang River estuary wetland, and the inhibition increased with the intensity of human disturbance. The data for cumulative mineralized CO_2-C showed a good fit(R^2 > 0.91) to the first-order kinetic model C_t = C_0(1 – exp(–kt)). The kinetic parameters C_0, k and C_0 k were significantly affected by human disturbance and water conditions. In addition, the total amount of mineralized C(in 49 d) was positively related to C_0, C_0 k and electrical conductivity of soils. These findings indicated that anthropogenic disturbance suppressed the organic C mineralization potential in subtropical coastal wetland soils, and changes of water pattern as affected by human activities in the future would have a strong influence on C cycling in the subtropical estuarine wetlands.

Employing Constructed Wetlands to Sustainably Manage Nutrient-Bearing Water: A Review with an Emphasis on Soil Behavior and Effluent Nutrient Reduction

Constructed wetlands are engineered structures designed to simulate processes of natural wetlands to mitigate anthropogenic organic and inorganic materials to shelter soil and water resources. This review focuses on the global interest in constructed wetland application to sustain soil health and water quality and water abundance. Engineering criterion remains a function of nutrient chemistry and load with suitability factors including the local soil and hydrogeology constraints, climate, vegetation selection, the degree of required influent improvement, and reactor types and sizes. Future research needs to focus on: 1) reactor designs criteria, 2) the biology of the microbial community, 3) selection criteria for native vegetation, and 4) criteria to reapply treated water to foster land productivity, especially for region’s experiencing water deficiencies.

Exploitation of groundwater resources and protection of wetland in the Yuqia Basin

In Yuqia Basin, the climate is arid and the ecologic environment is fragile, and shortage of water resources has seriously restricted the sustainable development of local economy. In order to meet the needs of industrial and domestic water in the Yuqia Basin, numerical simulation was used to evaluate the groundwater resources and potential for exploitation. The results showed that the mathematical model and calculation parameters used were mainly in accordance with practical situation. The calculated value of the underground water level is consistent with measured value during the period of identification and validation. The total recharge of groundwater resources was 22.02×10~4 m^3/d, and the total drainage was 21.95×10~4 m^3/d at present. The Yuqia River leakage is the main supply source of groundwater. There is no significant effect on area of wetland when water source place exploited by 2.5×10~4 m^3/d at alluvial-diluvial fan of Yuqia River. After long-term exploitation, the spring flow reduces from 1.42×10~4 m^3/d to 1.01×10~4 m^3/d and wetland area reduces by 32.7% of original area. The calculation of water balance shows that it is safe to the Yuqia Basin, Da Qiadam Lake, the Mahai Basin at downstream of Yuqia River and wetland under the condition of water source place exploited by 2.5×10~4 m^3/d.

Constructed Wetland Systems as a Methodology for the Treatment of Wastewater in Bucaramanga Industrial Park

Effluent discharges from municipal, industrial, and agricultural activities constitute major sources of pollution on land and water bodies. During the 1990s, large-scale application of Constructed Wetlands (CWs) as a remediation option drew much attention globally from the public and green groups alike. The most common application of CWs is for flow management in river system and little is documented on using CWs for treating polluted river water. This article goes beyond constructed wetlands as a stand-alone methodology to propose an integrated remediation system incorporating constructed wetlands in Bucaramanga Industrial Park S.A., Santander (Colombia), which will form part of an innovation park. In addition to pollution abatement, the project is projected to provide other environmental benefits to the entire Oro River Sub-basin. Other benefits of the project include mitigation of environmental impacts, improvement in water quality, landscape amenity, as well as tourism and recreational benefits.

Influence of Wetland Self-purification Capacity on the Utilization of Water Resources——A Case Study of the Project for Recycling Yanshan River Water

[ Objective] The study aims to resolve water resource problem availably. [ Method] On the basis of wetland self-purification capacity, Yanshan River water was purified by Xixi Wetland, and the feasibility of using treated Yanshan River water for urban greening and watering road was analyzed. [Result] Compared with direct utilization of tap water, it is more economic to recycle Yanshan River water purified by Xixi Wetland for urban greening and watering read, with obvious economic, ecological and social benefits, so it is an effective method to address shortage of water resources and is worth spreading. [ Conclusion] It is feasible to use Yanshan River water purified by Xixi Wetland for urban greening and watering read.

Constructed Wetlands as a Natural Resource for Water Quality Improvement in Malaysia

Tropical wetlands have numerous natural functions, one of which is the filtration of wastewater for water quality improvement. The aim of this paper is to investigate the performance of constructed wetlands in Universiti Sains Malaysia for water quality treatment of stormwater runoff. A total of 17 sampling stations were selected from different sections of possessing different compositions, characteristics and plant species. Weekly physico-chemical and biological parameters were analysed during the one year period starting from December 2010 to December 2011. The results exhibited significant improvement of water quality as the concentration of nitrate, nitrite, ammoniacal-nitrogen, orthophosphate, TSS, BOD and COD decreased after the water passed through the macrophyte and micropool zones before being discharged to the wetland outlet. The concentration of nitrite was significantly reduced (80%);nitrate (61.56%), ammoniacal-nitrogen (51.49%), orthophosphate (60.98%), TSS (67.86%), BOD (27.7%) and COD (46.43%). The decrease in the concentrations of the above pollutants showed that the improvement of water quality was performed in the wetland. Most of the concentrations fall in Class IIA and IIB based on National Water Quality Standards for Malaysia and Department of Environment (DOE) Water Quality Index Classification. Biological measurement showed high diversity of species. Based on the results obtained, the macrophyte zone showed a high number of species and percentage distribution of phytoplankton and zooplankton, starting from the Wetland 1and 2 until the outlet wetland (14.6% - 14.9% until 3.5%). While for fish distribution, Oreochromis niloticus was the dominant fish species from the others seven species found in the constructed wetland. Overall, the results from this study demonstrate that constructed wetlands significantly improve water quality of stormwater runoff, and that they are a good natural resource for the sustenance and maintenance of biodiversity.

Impact of Land Use and Aquatic Plants on the Water Quality of the Sub-Tropical Alpine Wetlands in India: A Case Study Using Neuro-Genetic Models

The suspended and dissolved waste in the incoming storm water of wetlands largely depends on the adjacent land use which can influence the quality of the water body. The micro- and macro-floral population of a wetland can absorb, convert, transform and release different organic or inorganic elements, which can also change or impact the overall quality of the wetland water. The present study investigates the influence of the land use and the plant species in the waterbed on the water quality of a high-altitude, sub-tropical wetland in India. The estimation capabilities of neuro-genetic models were utilized to identify the inherent relationships between the Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), chlorine (Cl) and Chemical Oxygen Demand (COD) with the land use and wetland zoology. A thematic map of the quality parameters was also generated based on the identified relationship to observe the influence that the morphological and biological diversity in and around the study area has on the quality parameters of the wetland. According to the results, the BOD, COD and Cl were found to vary with differences in land use and the presence of different plant species, whereas the DO was found to be largely invariant with changes in these parameters. The reasons may be contributed to the impact of uncontrolled eco-tourism activities around the wetland.

Agricultural Soil and Water Quality Assessment and CO₂Storage on Wetland Reserve

In this paper, investigations on agricultural and forestry soil and on water quality assessment were carried out in a natural wetlands reserve, at valley of a mountain, near at the sea and under hydraulic risk (the coast of the Etruschis), in central Italy;Physical-chemical parameters were measured by taking samples of soil on two fields cultivated with an artichoke bed and respectively managed with organic and conventional techniques adjacent the natural wetlands reserve and destined to a controlled development of the agriculture, to protect the reserve. These parameters were also measured on forestry soil inside the reserve and CO2 storage on soil was evaluated. The water chemical analysis of the two ponds inside the reserve was also carried out. The soil managed with organic farming has showed higher chemical fertility. Both organic and conventional field showed high level of soil compaction susceptibility evidenced by high values of penetration resistance and shear strength;while porosity and hydraulic conductivity presented low values. The research highlights that the ecological land use can influence and improve the environmental quality. In fact thanks to the higher organic matter content into the soil, the average values of stored CO2 show that the organic (ΔCOT = 1200 kg·ha–1) and forestry (ΔCFT =2200 kg·ha–1·year–1) treatments have stored higher amount of organic carbon in the soil with respect to the conventional one. Organic matter and dry bulk density can be considered good indicators of the soil quality. The results of the water chemical analysis show a good quality of the brackish water of the ponds situated in the wetlands reserve.

Assessment of Irrigation Water Quality Parameters of Nyandungu Wetlands

The present paper sought to assess some physico-chemical parameters above permissible guidelines of irrigation water standard, the study was carried during establishment of Ecotourism Park. The field survey design was used and it was accompanied by laboratory tests to analyze the levels of physico-chemical parameters in both seasons (dry season and wet seasons) for water bodies as well as groundwater. The physical chemical parameters analysed were Sodium Adsorption Ratio (SAR), Soluble Sodium Percentage (SSP) Magnesium Adsorption Ratio (MAR) Kelly Index (KI) Total Hardness (TH), pH, the Electric conductivity (EC), Total Dissolved Solids (TDS). Our analyzed samples fall into permissible limit of irrigation water quality, the mean values of electrical conductivity were high. The knowledge from this study will be used in establishment of Nyandungu recreation park irrigating with water quality on gardens surrounding recreation park and local community.

Water Quality, Contamination, and Wetlands in the Croton Watershed, New York, USA

The Croton Watershed (New York State, USA) is a semi-urban region that provides 10% of the drinking water for the City of New York. Nonpoint source contamination in the watershed is a major concern for managers because the water supply is currently unfiltered water. Results are reported from three synoptic studies of surface water quality from 98 wetland-containing sub-catchments in the Croton Watershed designed to broadly characterize, at a reconnaissance level, the geochemical controls on water quality, in particular as it relates to wetlands. Total dissolved organic carbon concentrations in surface waters draining wetlands correlated well (average R2 of 0.93) with standard Gelbstoff (g440) color measurements, although there is very little correlation between dissolved organic carbon concentrations and wetland areas in the sub-catchments. This may be a potential indication of other sources of colored organic material. Concentrations of dissolved sodium and chloride, while related to road length, stochiometrically had more chloride than expected for pure road-salt dissolution. This offset is likely due to cation exchange and sorbtion of sodium by wetlands in the Croton watershed. The results show contamination in the Croton hydrologic system that should addressed in ongoing management policies and decision-making.

Dynamic Variation of Land-use Types of the Constructed Wetland before and after Oil-field Water Irrigation Based on 3S Technology

[Objective] The study aimed at analyzing the dynamic variation of land-use types of the constructed wetland before and after oil-field water irrigation based on 3S technology. [Method] At semi-arid and arid areas in the west of Jilin Province, water resource balance between the amount of oil-field water supply and ecological water requirement in the constructed wetland irrigated by oil-field water during 2001-2010 was investigated firstly. Afterwards, based on 3S technology, the partition and dynamic variation of land-use types of the constructed wetland before and after oil-field water irrigation in 2001, 2006, 2008 and 2010 were analyzed. [Result] The annual ecological water requirement of the constructed wetland from 2003 to 2010 varied from 1.62×106 to 2.24×106 m3, and the annual amount of oil-field water supply in the region changed from 2.12×106 to 2.84×106 m3, which showed that the supply amount of oil-field water could meet the basic ecological water requirement of the constructed wetland. Meanwhile, compared with 2001, the areas of water region and paddy field in 2010 increased by 2.3 and 10.0 times, and the areas of forest and marsh rose by 40.15% and 29.5.0% respectively. [Conclusion] Water shortage and ecological environment problem of arid and semi-arid areas had been improved by oil-field water irrigation.

Rain Water Utilizing System Combing Artificial Wetland and Urban Drainage System

The method of utilizing rain water has been well developed in foreign countries to realize the sustainable development of water recourse while the method is still at the initial level in China. When considering the increasing of water shortage and urban flood, the awareness of utilizing rain water, as an inevitable trend, has been applied to various engineering technologies. This article has analyzed the principle of conventional road drainage system and the application of artificial wetland technology, also proposed to combine the road drainage system and artificial wetland, as a complex drainage system, to utilize the urban rain water, decrease urban flood pressure, and improve urban micro environment. The calculation principle and method for the complex drainage system are included as well.

Application of a Stereo Constructed Wetland Mode to the Treatment of Slightly Polluted Source Water

[Objective] The study aimed to discuss the application of a stereo constructed wetland to the treatment of slightly polluted source water. [Method] In this study, a new stereo constructed wetland mode was put forward, and a pilot project of water ecological purification in Xinsheng River, the diversion channel of Shijiuyang Waterwork in Jiaxing City, were analyzed. Afterwards, the impact factors of water purification by the technology were discussed from water quality and quantity, season and climate, species configuration, management and maintenance. [Result] Under three different hydraulic loading conditions, the pilot project effectively improved water SD and DO level, and reduced SS, CODCr, NH3-N, TN and TP significantly in summer and autumn, so that effluent water quality reached surface water standard at Grade III. [Conclusion] The stereo constructed wetland mode composed of constructed wetland and underwater forest used to treat slightly polluted source water is feasible and has a good promotion prospect.

Application of Wild Water-wet Herbs in the Construction of Wetland Parks in Hefei

The plant resources of Chaohu Lake coast, Binhu Wetland Park, Xiaoyaojin Park and other places along Dongpu Reservoir surrounding Hefei Botanical Garden were investigated, from which 70 species of wild water-wet herbs with promising application prospects were selected. These wild wet-water herbs are a dominant group that adapts to local growth through long-term natural selection. They have strong resistance, low maintenance cost and broad application prospects. However, at present, these plants are basically in the natural growth state, and have not been developed artificially. This study aims to provide reference for the design of wetland parks and to show the local characteristics of Hefei through the investigation of wild water-wet herbs in Hefei area.