The USEPA has identified the excess release of nutrients as one of the top 5 causes of water quality “impairment” of rivers and streams in the U.S. along with pathogens, habitat alteration, organic enrichment, and unknown-impaired biota. Phosphorus enters natural waters as a result of point source and non-point source pollution. Point sources are primarily discharges from wastewater treatment plants , and non-point sources come from diffuse, difficult-to-identify, intermittent sources of pollutants such as urban and agricultural runoff. Agricultural soils obtain P from livestock, mineral fertilizers, and municipal sludges and waste waters resulting in a decrease of the soil’s capacity to retain P. The decreased P retention capacity of the soil can accelerate the loss of P into the watershed when there is heavy rainfall and runoff. Unlike point source P loads which are typically treated through physical, chemical, and biological processes including adsorption and precipitation using alum, ferric chloride, and lime at wastewater treatment plants, non-point source P loads are largely controlled through “Best Management Practices ”, economical and technically feasible ways to minimize P movement. Because of the tendency for phosphorus to sorb to soils, P usually moves with the soil or sediment during significant rainfall events. Research has shown that within a landscape, 50 to 95 percent of P transports through moving sediments, recognized as the largest pollutant in our waters by volume and mass. Sediments are released into water bodies via bed and bank erosion,aeroponic tower garden system and overland erosion and therefore erosion control is a key method for decreasing non-point source P inputs to water bodies.
However, erosion control by itself will not be completely effective since a significant fraction of P is still in a colloidal or dissolved form particularly when high source loads decrease or eliminate the adsorption capacity of the soils and sediments. River bank stabilization and reactive stream stabilization are both effective BMPs for reducing and preventing phosphorus from entering the watershed. RBS can be installed alone or installed with RS2 to achieve additional amounts of phosphorus and nitrogen removal. The RS2 is a system that is designed to stabilize the stream and minimize release of agricultural non-point pollutants from farms, waste sites, and animal feed lots to the stream through erosion. The RS2 diverts groundwater and surface water runoff through materials in the reactive barrier that enhance microbial and physical nutrient removal. The nutrient removal efficiency of the RS2 system has been demonstrated by Watson’s 2003 to 2006 study at the Colorado State University Engineering Research Center . Watson et al. found that the RS2 structure utilizing water treatment residual as the reactive barrier material had the best phosphorus removal efficiency among the 3 evaluated materials; sawdust, WTR, and zero-valent iron . WTR is an aluminum based media that is the residual from the coagulation and settling processes in a water treatment system and it has the capability of adsorbing large amounts of phosphorus.When sand amended with 15% WTR was used as the reactive barrier, 98% phosphorus removal and greater than 90% nitrate reduction was measured. Based on the results of the field study at CSU, a RS2 structure was installed at a site along a stream bank of the Little Bogue Creek in Elliott, Mississippi in November 2008 . The scope of the research was to assist in design and installation of a field scale RS2 structure and to conduct assessment of the initial nutrient removal performance of the system. For this research, the objectives that were established given the time frame of the project were: 1) Assist in design and installation of field scale RS2 structure. 2) Document construction of RS2 structure and evaluate adherence to construction design parameters. 3) Provide initial data collection and evaluation of RS2 performance for limiting P and N transport to stream.
To evaluate design parameters of RS2, concentrations of alum and total organic carbon in the RS2 test barrier and surrounding areas were analyzed to determine if enough of them are in the barrier to remove nutrients as it was designed. After RS2 installation, soil and water samples were collected to begin understanding the structure’s nutrient removal effectiveness. Sampled soils were classified and total phosphorus , Mehilch-3 P, TOC, total nitrogen and aluminum were measured for soil concentrations and TP, dissolve reactive phosphorus , TN, nitrate and TOC were determined for water concentrations. A schematic diagram of the sampling sites is shown in Figure 2. Two sampling campaigns were conducted in 2009 with soil and water samples being collected along the Little Bogue Creek in Elliot, Mississippi . Little Bogue creek is a well-suited place to study a RS2 system because it is surrounded by agricultural areas and the only expected source of nutrients in the stream is the nearby agricultural lands since there are no upstream WWTPs. For the first sampling campaign, five soil samples were collected from both the lower bank of the barrier , upper bank of the barrier near the agricultural field and ten additional soil samples were taken from the reactive barrier at two different depths; 16 inches and 36 inches to observe differences and accumulation of P. For the second sampling, five soil samples were collected from the lower bank of the barrier , upper bank of the barrier near the field and the 16 inches deep reactive barrier . Each soil sample was collected in a labeled plastic zip bag. A well sampler was used to collect water samples from previously installed observation wells. The well sampler used was a rod-shape device 5 feet long that could be lengthened by 10 feet to reach ground water in the monitoring well. A volume of 0.5 L was taken from the monitoring wells LB2, LB3, LB4, LB5 and LB6, and four surface water samples were collected from upstream, adjacent to RS2 and downstream of the testing sites. Stream samples were collected from the center of the stream in clean, one liter Nalgene bottles. After sampling, all of the samples were placed in ice bags to maintain low temperature while they were transfered to the laboratory for analysis. Soil samples were air-dried, ground and passed through a 2-mm sieve before being transferred to a freezer. Water samples were filtered through Whatman No.42 filter paper then preserved in a refrigerator to avoid further reactions that could affect later measurement of the samples. All samples were measured within 28 days. The RS2 was designed according to previous field tests at the ERC of CSU from 2003 to 2006.
For these tests, a mixture of 15% of WTR with sand was used in the reactive barrier and 98% phosphorus removal was achieved through the barrier. From the result of the test, 10 to 20 % volume fraction of WTR and 15 to 20 % of volume fraction of mulch were targeted for the RS2 reactive barrier in the Little Bogue watershed.Eucalyptus mulch was applied as a source of organic matter to provide electron donors for denitrification in the 150 ft long reactive barrier. A 75 ft long area adjacent to the barrier was used as a control section and it had no added aluminum or organic matter. Construction of the RS2 was completed in November, 2008 in a location where bank stabilization in the form of longitudinal peak stone toe protection already existed. A 150 foot long, 4 foot deep and 1 foot wide trench was dug with a mini-excavator. Each 1.5 cubic foot bag of eucalyptus mulch was mixed with two 0.81 cubic foot bags of aluminum sulfate and native soils in the trench . Since the weight fraction of aluminum was the main design criterion of the RS2 design for P adsorption, calculating the weight concentration of aluminum in the barrier was critical. Since the volume of trench was approximately 600 cubic feet, the volume percentage of OM and alum in trench were 18.7% and 20.2%, respectively, and the corresponding weight percentage of aluminum should be 1.7%. This weight percentage of aluminum was equivalent to 18% v/v of WTR since the weight fraction of aluminum in WTR is 0.094. After mixing alum and mulch with the native soils in the trench, poles of river birch, sycamore and willow were planted in increments of each 25 feet along the test trench and the rest of 75 feet of the trench remained without pole planting. To enhance infiltration of rain and surface runoff into the barrier, dutch buckets for sale a small berm was built stream-side of the trench and a gully on the top bank was restored. Excessive soils on the barrier, the berm and the repaired gully were removed and top soils were flattened and then seeded with winter rye grass and mulched hay. Six monitoring wells were installed in January, 2009. Three of them were placed on the stream-side bank and three on the field side of the reactive barrier to monitor nutrients in the ground water passing through the barrier. Five months after the RS2 construction, the first sampling campaign was conducted in the test and control areas. Water samples were collected from the installed monitoring wells and the up-, mid- and down-stream sections of the creek. Soil samples were taken from the barrier and the stream bank on both the field-side and stream-side of the barrier.
The second sampling campaign was carried out in July, 2009. Public signs refer to all characters and figures used to inform, instruct, compel or warn something that is closely related to our ordinary life and production. Usually, public signs are short and brief, normative, unified, conspicuous, with simple structure, plain meaning and proper style. Due to their specific functions , public signs act as a carrier of a city’s image and have great impact on the tourists’ experience. Researches on the public signs boomed after 2003, featured by a hurried start, sharply increasing demand, short history and lacking of precedent. With the development and prosperity of tourism industry in China, cites at different scales are striving to explore their knock-out tourism product with marked local features. Meanwhile, most famous scenic areas have provided bilingual or multilingual translations of the public signs to improve their service, facilitate the tour and attract more foreign tourists. Yibin is located in the south of Sichuan Province, lying to Yunnan and Guizhou to its south, where Jinshajiang, Minjiang and Yangtze River meet. It is considered the richest southwestern city in ancient China and the first city on the Yangtze River. Yibin is both rich in natural tourism resource and human culture resource, and therefore is honored as one of the famous national historic and cultural cities and the favorable tourist cities. As the birthplace of Luzhou-flavor liquor and one of the world famous liquors—Wuliangye, Yibin is hailed as the Capital of Liquor in China. The majestic Wuliangye Ten-Mile City is built due to the rapid development of liquor industry, which is not only filled the gap of enterprise architecture culture but also became the invaluable treasure of the Chinese architecture art. Thousands of admiring tourists from home and abroad were attracted every year. However, flaws still exist in the Chinese-English translation of public signs, which will not only bring inconvenience to foreign tourists but also have negative impact on the images of the scenic area, the enterprise and even the city. Thus, it is an urgent and non-negligible task to remove those flaws in the translation of public signs in order to promote the transmission of Wuliangye’s liquor culture.Translation principles refer to the rules a translator should abide by, and they are regarded a necessary basis to generate qualified translation and meanwhile to restrict over-translation. Chinese scholars have conducted in-depth research on the translation of the public signs, and proposed several principles from different views or based on several theories, which provided guidelines for translators. The following principles have been universally accepted by domestic scholars: 1) Accurate Being accurate and unified means that there should be no mistakes and flaws in the translation, and the translation should convey all the information provided by original text. Only accurate translation can play its informing, indicating, compelling, warning and servicing functions.