In recent years, many construct wetlands in Taiwan have been built for the purposes of wastewater treatment, river water purification, and ecology conservation. To evaluate the effectiveness of constructed wetlands on water purification, frequent water quality monitoring is needed. In this study, the multivariate statistical analysis was applied to evaluate the contaminant removal efficiency in a constructed wetland, and the time series method was then used to predict the trend of the indicative pollutant concentration in the wetland. Multivariate statistical analysis simplifies the original data into representative factors, or hive off the similarity between data to cluster, and then identify clustering outcomes. In this study, an artificial wetlands at the site around an old bridge locates at the Kaoping River Basin was used as the study site. The statistical software SPSS 12.0 was used to perform the multivariate statistical analysis to evaluate water quality characteristics of its. Results from this study show that the removal efficiency for the total coliforms (TC) of System A and B was 98%, 55% for biochemical oxygen demand (BOD), 53% for chemical Oxygen demand (COD), 55% for ammonia nitrogen (NH3-N), and 39% for total nitrogen (TN). Moreover, suspended solids (SS) couldn¡¦t be removed in both A and B systems. The box-and-whisker plot indicates that the water quality of inflow was unstable and variable; however, outflow was turning stable with its flow direction. The major pollutant indicators, except SS, were all in a decreasing tendency. The paired t-test shows p value of each item were lower than 0.05, except total phosphorus (TP) in System A, nitrate nitrogen (NO3-N) and Chlorophyll a (Chl-a) in System B. The correlation parameters from TN, nitrogen oxides (NOx), NO3-N and nitrite nitrogen (NO2-N) and so on were all higher than 0.7. The factor analysis of SPSS shows that 17 water-quality items of the study site could obtain four to six principal components, including nitrate nutrition factor, phosphorus nutrition factor, eutrophication factor, organic factor, and environmental background factor, the major influencing components are nutrition factor and eutrophication factor. The ponds of the study site were classified into two or three clusters depend on in-and-out flow location. This study attempted to establish a forecasting model of wetland pollutants concentration through the time series (ARIMA), results show that the outcome of the B7 pond was better than others. Results indicate that the ARIMA model can be used to simulate the trend of treatment efficiency using the wetland system. Experience and results obtained from this study would provide solutions for water quality control.

In Taiwan, more than 20% of the major rivers are mildly to heavily pollute by domestic, industrial, and agricultural wastewaters due to the low hook-up rate of public underground sewerage systems in rural areas. Thus, constructed or engineered wetlands have been adopted as the major alternatives to cleanup polluted rivers. Constructed wetlands are also applied as the tertiary wastewater treatment systems to polish the secondary wastewater effluents to meet water reuse standards with lower operational costs. The studied Kaoping River Rail Bridge Constructed Wetland (KRRBCW) is the largest constructed wetland in Taiwan. It is a multi-function wetland and is used for polluted creek water purification and secondary wastewater polishment before they discharge into the Kaoping River. Although constructed wetlands are feasible for contaminated water treatment, wetland sediments are usually the sinks of organics and metals. In this study, water, sediment and macrophytes samples were collected from the major wetland basins in KRRBCW. The quarterly investigation (from 2007 to 2009) results show that more than 97% of total coliforms (TC), 55% of biochemical oxygen demand (BOD), and 30% of nutrients [e.g., total nitrogen (TN), total phosphorus (TP)] were removed via the constructed wetland system. However, results from the sediment analyses show that wetland sediments contained high concentrations of metals (e.g., Cu, Fe, Zn, Cr, and Mn), organic contents (sediment oxygen demand = 1.7 to 7.6 g O2/m2-d), and nutrients (up to 18.7 g/kg of TN and 1.22 g/kg of TP). Thus, sediments should be excavated periodically to prevent the release the pollutants into the wetland system and causing the deterioration of wetland water quality. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal that an increase in microbial diversities in the wetland systems was observed. Results from the DGGE analysis indicate that all sediment samples contained significant amounts of microbial ribospecies, which might contribute to the carbon degradation and nitrogen removal. Gradually disappearing of E. coli was also observed along the flow courses through the natural attenuation mechanisms. The factor analysis of SPSS 12.0 shows that 17 water-quality items of the study site could obtain four to six principal components, including nitrate factor, phosphorus factor, eutrophication factor, organic factor, and environmental background factor, the major influencing components are nutrition factor and eutrophication factor. The ponds of the study site were classified into two or three clusters depend on in-and-out flow location. This study attempted to establish a forecasting model of wetland pollutants concentration through the time series (ARIMA), results show that the outcome of the B7 pond was better than others. Results indicate that the ARIMA model can be used to simulate the trend of treatment efficiency using the wetland system. Experience and results obtained from this study would provide solutions for water quality control. Thus, the wetland system has a significant effect on water quality improvement and is capable of removing most of the pollutants from the local drainage system before they are discharged into the downgradient water body. Other accomplishments of this constructed wetland system include the following: providing more green areas along the riversides, offering more water assessable eco-ponds and eco-gardens for public, and rORPabilitating the natural ecosystem. The Kaoping River Rail Bridge Constructed Wetland has become one of the most successful multi-function constructed wetlands in Taiwan. The experience obtained from this study will be helpful in designing similar natural treatment systems for river water quality improvement and wastewater treatment.

A constructed wetland was built in southern Taiwan in 2007 for local stream water purification and ecosystem improvement. The inflow rate was approximately 1,350 m3/day. The wetland influents were mainly from the local streams containing secondary wastewater from hog farms located in the upper catchment of the wetland and drainage water from the farmlands. The influent water contained organic contaminants and nutrients, which needed to be removed. The mean measured hydraulic loading rate, hydraulic retention time, water depth, and total volume of wetland system were 0.1 m/day, 5.5 days, 0.7 m, and 7,800 m3, respectively. In this study, water, sediment, and plant samples were collected and analyzed quarterly for each wetland basin during the two-year investigation period. Results show that more than 77% of total coliforms (TC), 78% of biochemical oxygen demand (BOD), 88% of total nitrogen (TN), and 96% of ammonia nitrogen were removed via the constructed wetland system. Thus, the wetland system has a significant effect on water quality improvement and is able to remove most of the pollutants from the local stream through natural attenuation mechanisms. Results from the ecological investigation show that more than 50 different plant species and 45 different animal species were observed in the wetland system although this wetland had been created for less than four years. Except for stream water quality improvement and rehabilitating the natural ecosystem, this wetland also offered more water assessable eco-ponds and eco-gardens for public. This constructed wetland has become one of the most successful multi-function constructed wetlands in Taiwan.

In the process of pursuing economic growth as the national target for a long time, Taiwan has created an economic miracle but sacrificed ecological environmental sources. With increasing higher living standards, more living space is demanded such that providing clean and green spaces along riverbanks in addition to offering security becomes another important mission. In recent years, the global thinking of sustainable development has demanded more ecological and environmental protection such that efficient management of waters along river, drainage and seacoast will be emphasized tasks of watershed management. The main objective of pollution investigation and quantity estimation in Chiang-Chun River watershed is to effectively comprehend the sources of pollution to assist in establishing the water quality model to be used in simulation. The QUAL2E model developed by the US EPA is used to carried out estimating the carrying capacity of Chiang-Chun River, and drafting pollution control measures and waste reduction strategies so that the objective of improving Chiang-Chun River¡¦s water quality can be achieved. Chiang-Chun River has long been subjected to pollutions from industrial and domestic waste discharges resulting in serious water quality deterioration. Additionally the waste discharge from manufacturing plants along the creek has made the pollution even worse. Hence, various environmental protection authorities have actively promoted the checking and controlling industrial and pig-farming wastewater discharges and established a mechanism encouraging local residents to participate in the watershed pollution prevention and control. These measures will not only alleviate the water pollution in Chiang-Chun River with limited resources but also achieve the purpose of communing local residents and the river. V The livestock wastewater is currently treated in three-stage system including solid-liquid separation, anaerobic treatment and aerobic treatment. With good management, the effluent is expected to meet discharge standards. However, since most pig farmers, who may try to save costs, have not efficiently managed the treatment facility so that the treated effluent does not meet the standards. If directly discharged into surface bodies, the improperly treated effluent will cause serious pollution problems. A natural treatment and water purification system is currently being promoted. If implemented in the three-stage treatment system, the natural system (aquatic treatment system) will achieve energy savings, lower the difficulty to operate the treatment system and reduce the operation and maintenance costs. Additionally, effluent quality can be improved such that the possibility of water reuse is also expected. Providing adequate treatment for domestic wastewater requires the construction of sewage system, which is costly and may take a long time to complete. Additionally, since most residents are scattered in the watershed, the construction of conventional sewage system to collect domestic wastewater is not cost-effective. Hence, the natural system, e.g. constructed wetland, is proposed as the major method for treating the wastewater discharged from communities and for achieving water reuse such that multiple-functional benefits can be reached. Additionally, the concept and tasks of water pollution prevention and control can be deeply rooted in the community development so that a community possessing the capability of water self-purification and sustainable application is developed.

Constructed wetlands have been widely accepted as a natural ecotechnology for wastewater treatment. Constructed wetland system is a treatment system, while it utilizes intertine relationship among water, plants, soils, microorganism and atmosphere in natural environment, and applies natural physics, chemistry and biochemical actions to remove pollutions natural. In addition, the constructed wetland can also to increase the areas to attract more wild animals as their habits. In this study, we analyzed quality of Koping River Old Railroad Bridge constructed wetlands to understand the remove efficiencies for different pollutions. The analytical results showed that A system of the constructed wetlands because some other sewage of A system flowed into the system. However, the treatment system were still better than those in B system. The average removal efficiencies of BOD5 ,COD ,NH3-N ,TP in A system equal to 81.93¢H,50.98¢H,74.89¢H,46,70¢H,respectively. However the average removal efficiencies of SS and Chlorophyll-a were increased for both A and B systems, which might because algae can grow vigorously in summer. Resulting in an increase for both Chlorophyll-a and SS. Besides, in autumn the litter effect of wetland plants might cause the concentrations of nutrients increased. In addition, in this study we also utilized emergy analysis to evaluate the economical values while comparing with a sewage treatment plant. The analytical results showed that the constructed wetlands could remove more pollutants than of the sewage treatment plant. However, the constructed wetland system could still increase the biodiversity. If they could reach steady treatment efficiencies under proper operation and maintenance. It is concluded that the constructed wetland system can provide advantages in both ecology and economics systems.

Abstract A system with the combination of upflow anaerobic sludge blanket (UASB) reactor and constructed wetlands (CWLs) has not yet been applied for cleaning river water polluted by sewage and swine wastewaters. In this study, a pilot system with an UASB reactor (effective working volume 4.0 m3) combined with two CWL reactors (effective working volumes 4.8 and 5.4 m3 for CWL-1 and CWL-2, respectively) was used to test the feasibility for treating wastewater sampled from the Wu-Luo River. The river is located in Ping-Tong County of southern Taiwan and has long been polluted by untreated domestic and partially treated swine wastewaters and is among the most polluted rivers in Taiwan. A control system without the UASB reactor and with the CWL-1 and CWL-2 was also tested in parallel to the test system. In the test system, the UASB reactor was seeded with an anaerobic sludge for sewage treatment and CWL-1 and CWL-2 of both the test and control systems were planted with emergent macrophyte (Typha angustifolia L.) and floating macrophyte (Pistia stratiotes L.), respectively. In general, it requires hydraulic retention times (HRT) of 1-5 days for polluted waters in CWLs to obtain clarified ones. In the present study, HRT of the test water in the system was reduced from around 34 to 11 hours to examine the clarification effect. Results indicated that the influent water has the following average qualities (unit in mg/L): total COD (CODt) 61, BOD 14, suspended solids (SS) 156, total-N 24, ammonia-N 12, nitrate-N 3.9, nitrite-N 0.92, and total-P (TP) 41. Results also indicate with a total HRT of 11.3 hrs, the test system (UASB-CWL1-CML2) could achieve average removals of 62% CODt, 56% BOD, 75% SS, 37% TN, 44% ammonia-N, 54% nitrate-N, 47% nitrite-N, and 61% TP from the influent water. The effluent water has the following average qualities (unit in mg/L):CODt 19, BOD 6.1, SS 15, TN 15, ammonia-N 7.5, nitrate-N 1.8, nitrite-N 0.49, and TP 1.7. The study indicates that the UASB could act as a preliminary device for sedimentation of most of the influent suspended solids and hence preventing the accumulation of sludge in the following CWLs.

Abstract Constructed wetlands can be treated as a imulated natural treatment system,which use solar adiation as the source of energy. By analogy with some removalmechanisms in natural wetlands, constructed wetlands are able to transform and remove pollutants from the wastewater. Other features provided by the constructed wetland include wildlife support, hydrologic odification, erosion protection, and open space and aesthetics. It has been applied for domestic wastewater purification for decades. The goal of this study was to evaluate the ffectiveness of using constructed wetlands on industrial wastewater treatment. In this study, grit chamber and furnace waste from steel-making were used as the media for plant growth. Two -tank (dimension for each tank: 4L ¡Ñ1W ¡Ñ1H) system was designed and constructed to simulate the constructed wetland. Reed and cattail were planted in the first and second tanks, respectively. In the system, media in the first and second tanks were filled to a height of 0.4 m (furnace waste from steel-making) and 0.1 m (waste grit), respectively. The depth of water was maintained at 0.3 m. The hydraulic retention time was approximately 5 days. The following parameters were analyzed during the operational period: nutrients, chemical oxygen demand (COD), suspended solids (SS), and biochemical oxygen demand (BOD). The calculated removal rates (g/m2/day) in the first tank were¡GCOD 5.92¡Ó0.64¡BBOD 3.48¡Ó0.95¡BSS (suspended solids) 3.42¡Ó1.44¡BTKN (total kjedal nitrogen, TKN) 0.94¡Ó0.26¡BTP (total phosphorus) 1.33¡Ó0.2¡CThe removal rates (g/ m2/day) in the second tank were: COD 5.17¡Ó0.62¡BBOD 3.21¡Ó0.92¡B SS 2.92¡Ó1.29¡BTKN 0.59¡Ó0.21¡BTP 0.66¡Ó0.15. Results from this study indicate that the media and plants in both tanks created a biofiltration system for microbial growth and pollutant removal. Sorption and biodegradation were the two major pollutant removal mechanisms in the system. During the operational period, the average removal efficiencies (%) in the first tank were: COD 55~62, BOD 73~90, SS 66~84, TKN 36~66, TP 28~39. The average removal efficiencies (%) in the first tank were: COD 49~54, BOD 73~83, SS 45~69,TKN 15~43, TP 9~24.

The frequency of on-site systems for treatment of domestic wastewater is increasing with new residential development in both rural and low-density suburban areas. Subsurface flow constructed wetlands (SFCW) have emerged as a viable option to achieve advanced or secondary treatment of domestic wastewater. The pollutant removal efficiency in SFCW depends on design parameters. Many of these factors have been investigated while others such as aspect ratio, design of water inlet structure and method of dosing the wetland have yet to be fully examined. This study examined the effect of aspect ratio and header design on BOD5 removal efficiency as well as the impact of flow rate on flow distribution in a SFCW. An aspect ratio of 4:1 achieved 10% greater removal of organic matter than a 1:1 ratio. Tracer studies demonstrated that wetlands loaded at a constant rate of 3.8 L/min and 7.6 L/min experienced preferential flow. In addition, tracer studies showed wetlands with leaching chambers as headers failed to achieve equal flow distribution. An improvement in effluent water quality was achieved by replacing the leaching chamber for a perforated manifold as the inlet structure. This study demonstrated the importance of the careful selection of aspect ratio and means by which water is introduced to the wetland in the design of SFCW.

The Dapeng Bay National Scenic Area will be planned as an interna-tional level tourism site. In order to improve the water quality in bay area, the administration authority has removed oyster farm. However, sewage and aquaculture wastewater from the communities and fish ponds around the bay area were still discharged continuously. After careful assessment, The Dapeng Bay National Scenic Area Administration authority decided to use constructed wetlands to treat such kinds of wastewater. In this study, the treatment efficiencies of Datan Constructed Wetland Park were investigated. According to the experimental results, we found that the remove efficiencies of SS, Chl-a, and TOC were not good enough, while the other parameters, such as OP, TP, NO2-, and NO3- their all re-moval efficiencies were all above 40¢H.The removal efficiencies of NH3, TKN and TN were all above 60%. However, the removal efficiencies of turbidity and BOD were found equal to 30%. Generally, TN was removed by the process as of nitrification and denitrification, but the nitrification of the subsurface flow¡]SSF¡^part of wetland was perforated worse, which caused the org-N and NH4+-N was not availably to become the NH3, NO2- and NO3-. Because of this reason, the removal effect of Org-N was not very significant. The parameter of TOC was affected by the fixation of CO2 through photosynthesis of autotrophs, and the respiration and denitrification of heterotrophs. The sediment also could provide organic carbon source for denitrification. Photosynthesis and carbon source would cause the re-moval efficiency of TOC become worse than synthesis. In the wetland, the decrease rate of salinity was found above 20¢H.

Constructed wetland (CW) system is one natural purifying process. Using the CW systems to treat industrial wastewater or domestic sewage has been extensively application in many countries. Constructed wastewater treatment wetland must depend on the optimal operation parameters to achieve the best treatment efficiency. The objective of this research was to evaluate the effectiveness of Kaoping River Rail Bridge Constructed Wetland (KPCW) on contaminated river water treatment. The major influents came from the treated industrial wastewater from a paper mill [Yuen Foong Yu paper manufacturing company (System A)] and local drainage system (Chu Liao River) containing untreated domestic wastewater (System B).Results from this study show that the measured flow rates for Systems A and B systems were 10,968 and 13,147 m3/day, respectively. The hydraulic loading rates (HLR) and hydraulic retention time (HRT) for Systems A and B were 0.085 and 0.096 m/day, and 5.4 and 10.7 d, respectively. The average removal efficiencies for both systems ranged from 63.4-71.7% for biochemical oxygen demand (BOD), 39.5-44.4% for chemical oxygen demand (COD), 28.1-39.5% for ammonia nitrogen (NH4-N), 17.1-40.3% for total nitrogen (TN), 5.4-45.5% for total phosphorus (TP), and 91.1-98.7% for total coliform (TC). Reduction in suspend solid (SS) concentration was ineffective in both systems. This was due to the irregular harvest of the plants in the wetland. Results from the effluent probability method (EPM) evaluation indicate that the removal efficiency increased with the increase in influent pollutant concentration. Moreover, variations in pollutant loading rate (PLR) would affect both the removal rates and effluent concentrations. The experience obtained from this project will be helpful in designing similar natural water treatment systems for river water quality improvement for other river basins.