Synthesis and application of lignin-based copolymer LSAA on controlling non-point source pollution resulted from surface runoff

In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safety were studied.The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants.The runoff quantity was decreased by 16.67%-47.00%and the loads of total suspended solids (TSS),chemical oxygen demand (COD),total nit...

GIS and L-THIA Based Analysis on Variations of Non-point Pollution in Nansi Lake Basin,China

Non-point source （NPS） pollution is the main threat to regional water quality, and the estimation of NPS pollution load has become an important task for NPS pollution control in China. Combined with geographical information system （GIS）, the long. term hydrologic impact assessment （L-THIA） model was used to evaluate the temporal.spatial changes of chemical oxygen demand （COD）, total nitrogen （TN） and total phosphorus （TP） in Nansi Lake basin from 2000 to 2010. The results show： 1 ） the estimated COD, TN and TP loads in 2010 are 260017.5, 111607. 7 and 6372.0 t with the relative errors of 2.1%, 2. 0 % and - 8.8 % respectively, and more than 90% concentrated in the raining period from June to September; 2） cultivated land and construction land take up more than 80% of the whole Nansi Lake basin, and the proportions of the three kinds of NPS pollution loads coming from cultivated land and construction land are more than 98%; 3 ） during 2000- 2010, the COD, TN and TP loads increase by 8801. 6, 180.3 and 71.9 t respectively, and become the main impact factors on the water quality of Nansi Lake.

Approach to estimating non-point pollutant load removal rates based on water environmental capacity: a case study in Shenzhen

An innovative approach based on water environmental capacity for non-point source NPS pollution removal rate estimation was discussed by using both univariate and multivariate data analysis.Taking Shenzhen city as the study case a 67% to 74% NPS pollutant load removal rate can lead to meeting the chemical oxygen demand COD pollution control target for most watersheds.In contrast it is hardly to achieve the ammonia nitrogen NH4-N total phosphorus TP and biological oxygen demand BOD5 pollution control target by simply removing NPS pollutants. This highlights that the pollution control strategies should be taken according to different pollutant species and sources in different watersheds rather than one-size-fits-all .

Factors Influencing Runoff P Losses from Farmlands of the Dianchi Lake Watershed in Yunnan, China

Effects of factors such as slope, surface soil textuie, fertilization andcrop cover with different rainfall intensities on phosphorus (P) losses in farmland runoff of theDianchi Lake Watershed in Yunnan Province of China were studied through a rainfall simulation testusing a red soil, one of the most widely distributed soils of the study area. Results showed thatthe runoff concentrations of total phosphorus (TP) and P losses differed with the slope, beinghighest when the slope was 18 deg. At twodifferent rainfall intensities, the runoff TP and P losseshad a similar decreasing trend as the surface soil texture became coarser, therefore applying thegrit would decrease P in runofi from soils of farmland on slopes with heavier textures. With wheatas a crop cover the runoff TP concentrations and P losses were significantly lower than those of thebare soil. This showed that plant cover would greatly decrease P in runoff from the farmland of thestudy area. The TP concentration in runoff from the soil two days after fertilization doubled whencompared with that from the non-fertilized soil, indicating that fertilization could mean a dramaticrise in P runoff if irrigation or heavy rainfall occurred immediately after application and that nofertilization before a rain and no irrigation immediately after fertilization would reduce runoff Ploss from the farmland of the study area.

Field test of best management practice pollutant removal efficiencies in Shenzhen,China

This paper presents a study on the use of best management practices(BMPs)for controlling nonpoint pollution in the Xikeng Reservoir watershed located in Shenzhen,China.A BMP treatment train design,including a pond,a wetland,and a buffer strip placed in series was implemented at the reservoir location.A separate grass swale was also constructed at the site.Low impact development(LID)BMPs,namely a planter box and bioboxes,were used at the parking lot of the reservoir’s Administration Building.Samples were collected during storm events and were analyzed for total suspended solids(TSS),biochemical oxygen demand(BOD5),ammonia nitrogen(NH3-N),and total phosphorus(TP).The removal efficiencies of both BMP systems were evaluated using the Efficiency Ratio(ER)method based on the event mean concentration(EMC)data.In summary,the pond/wetland treatment train removed 70%–90%of TSS,20%–50%of BOD5,and 30%–70%of TP and NH3-N.The swale removed 50%–90%of TSS,30%–55%of BOD5,–10%–35%of NH3-N,and 25%–70%of TP.For the planter box and biobox,the ranges of removal rates were 70%–90%,20%–50%,and 30%–70%for TSS,BOD5,and ammonia and phosphorus,respectively.

Zoning of rural water conservation in China:A case study at Ashihe River Basin

With the effective control of point source(PS)pollution accomplished,water pollution problems caused by non-point source(NPS)pollution have increased in recent years.The worsening agricultural NPS pollution has drawn the attention of the Chinese Government and researcher scientists and has resulted in the often mentioned“three red lines”on water resources management.One of the red lines is to control water pollution within a rational range.The Agricultural NPS pollution,which includes pollution from housing,and from livestock and crop production,is the main source.Based on the NPS pollution statutes,an index system for integrated evaluation of water quality,and a zoning scheme for rural water conservation were established.Using the method of one-dimensional Euclidean distance,this country is divided into 9 sub-zones at the provincial level,which are the first level zones.The zoning themes include natural resources,socio-economic development,water use efficiency,and pollutants emission intensity.According to pollution types of livestock,agriculture,or both,the first level zones are divided into 25 second level zones.The third class zoning is divided also based on pollution intensity of total nitrogen(TN),total phosphorus(TP),ammonia nitrogen(NH3-N),chemical oxygen demand(COD),and biochemical oxygen demand(BOD).On the basis of the second level zoning,there were formed 70 rural water conservation third level zones.This case study in the Ashihe river watershed indicated that the main pollution sources are consistent with the zoning research result,and this zoning has shown a good way to guide the agricultural NPS pollution control in not only the wide rural area of China but also other parts of the world.&2015 International Research and Training Center on Erosion and Sedimentation and China Water and Power Press.Production and Hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).

Mortality rates of pathogen indicator microorganisms discharged from point and non-point sources in an urban area

This research measured the mortality rates of pathogen indicator microorganisms discharged from various point and non-point sources in an urban area. Water samples were collected from a domestic sewer, a combined sewer overflow, the effluent of a wastewater treatment plant, and an urban river. Mortality rates of indicator microorganisms in sediment of an urban fiver were also measured. Mortality rates of indicator microorganisms in domestic sewage, estimated by assuming first order kinetics at 20℃ were 0.197 day^-1, 0.234 day^-1, 0.258 day^-1 and 0.276 day^-1 for total coliform, fecal coliform, Escherichia coli, and fecal streptococci, respectively. Effects of temperature, sunlight irradiation and settlement on the mortality rate were measured. Results of this research can be used as input data for water quality modeling or can be used as design factors for treatment facilities.