Hydraulic Performance of the Denitrification Bioreactor

Denitrification bioreactors, also known as woodchip bioreactors, are a new strategy for improving drainage water quality before these flows arrive at local streams, rivers, and lakes. A bioreactor is an excavated, woodchip-filled pit that is capable of supporting native microbes that convert nitrate in the drainage water to nitrogen gas. The idea of these edgeof-field treatment systems is still relatively new, meaning it is important for investigations to be made into how to design these “pits” and to determine how drainage water moves through the woodchips. Because the bioreactor at the ISU Northeast Research Farm (NERF) is one of the best monitored bioreactor sites in the state, it provided an ideal location to not only monitor bioreactor nitrate-reduction performance, but also to investigate design hydraulics.

(Table 1) Cation exchange capacity and other characteristics of soils common in Lower Saxony, Germany

The chemical and biochemical processes associated with the filtration of rainwater through soils, a step in groundwater recharge, were investigated. Under simulated climatic conditions in the laboratory, undisturbed soil columns of partly loamy sands, sandy soils and loess were run as lysimeters. A series of extraction procedures was carried out to determine solid matter in unaltered rock materials and in soil horizons. Drainage water and moisture movement in the columns were analysed and traced respectively. The behaviour of soluble humic substance was investigated by percolation and suspension experiments. The development of seepage-water in the unsaturated zone is closely associated with the soil genetic processes. Determining autonomous chemical and physical parameters are mineral composition and grain size distribution in the original unconsolidated host rock and prevailing climatic conditions. They influence biological activity and transport of solids, dissolved matter and gases in the unsaturated zone. Humic substances, either as amorphous solid matter or as soluble humic acids play a part in diverse sorption, solution and precipitation processes.

Calibration of WAVE in irrigated maize: fallow vs. cover crops.

Nitrate leaching decreases crop available N and increases water contamination. Replacing fallow by cover crops (CC) is an alternative to reduce nitrate contamination, because it reduces overall drainage and soil mineral N accumulation. A study of the soil N and nitrate leaching was conducted during 5 years in a semi-arid irrigated agricultural area of Central Spain. Three treatments were studied during the intercropping period of maize (Zea mays L.): barley (Hordeum vulgare L.), vetch (Vicia villosa L.), and fallow. Cover crops, sown in October, were killed by glyphosate application in March, allowing direct seeding of maize in April. All treatments were irrigated and fertilised following the same procedure. Soil water content was measured using capacity probes. Soil Nmin accumulation was determined along the soil profile before sowing and after harvesting maize. Soil analysis was conducted at six depths every 0.20m in each plot in samples from 0 to 1.2-m depth. The mechanistic water balance model WAVE was applied in order to calculate drainage and plant growth of the different treatments, and apply them to the N balance. We evaluated the water balance of this model using the daily soil water content measurements of this field trial. A new Matlab version of the model was evaluated as well. In this new version improvements were made in the solute transport module and crop module. In addition, this new version is more compatible with external modules for data processing, inverse calibration and uncertainty analysis than the previous Fortran version. The model showed that drainage during the irrigated period was minimized in all treatments, because irrigation water was adjusted to crop needs, leading to nitrate accumulation on the upper layers after maize harvest. Then, during the intercrop period, most of the nitrate leaching occurred. Cover crops usually led to a shorter drainage period, lower drainage water amount and lower nitrate leaching than the treatment with fallow. These effects resulted in larger nitrate accumulation in the upper layers of the soil after CC treatments.

An intensive survey of the Big Muddy main stem from Rend Lake to the Mississippi River Summer 1988 /

"IEPA/WPC/91-56."--Cover.

Effects of substrate type on plant growth and nitrogen and nitrate concentration in spinach

Abstract The effects of three commercial substrates (a mixture of forest residues, composted grape husks, and white peat, black peat and coir) on plant growth and nitrogen (N) and nitrate (NO3) concentration and content were evaluated in spinach (Spinacia oleracea L. cv. Tapir). Spinach seedlings were transplanted at 45 days after emergence into Styrofoam boxes filled with the substrates and were grown during winter and early spring in an unheated greenhouse with no supplemental lighting. Each planting box was irrigated daily by drip and fertilized with a complete nutrient solution. The NO3 content of the drainage water was lower in coir than in the other substrates. However, shoot NO3 concentration was not affected by substrate type, while yield and total shoot N and NO3 content were greater when plants were grown in peat than in the mixed substrate or the coir. Leaf chlorophyll meter readings provided a good indication of the amount of N in the plants and increased linearly with total shoot N. Keywords Spinacia oleracea; chlorophyll meter; coir; peat; soilless culture systems

Effects of substrate type on plant growth and nitrogen and nitrate concentration in spinach.

The effects of three commercial substrates (a mixture of forest residues, composted grape husks, and white peat, black peat and coir) on plant growth and nitrogen (N) and nitrate (NO3) concentration and content were evaluated in spinach (Spinacia oleracea L. cv. Tapir). Spinach seedlings were transplanted at 45 days after emergence into Styrofoam boxes filled with the substrates and were grown during winter and early spring in an unheated greenhouse with no supplemental lighting. Each planting box was irrigated daily by drip and fertilized with a complete nutrient solution. The NO3 content of the drainage water was lower in coir than in the other substrates. However, shoot NO3 concentration was not affected by substrate type, while yield and total shoot N and NO3 content were greater when plants were grown in peat than in the mixed substrate or the coir. Leaf chlorophyll meter readings provided a good indication of the amount of N in the plants and increased linearly with total shoot N.

Water and salt movements in simultaneous flood-irrigation and well-drainage operations

This paper describes a new technology for solonchak soil reclamation in which surface flood irrigation of fresh water and pumped wells drainage of salty groundwater are combined. The comprehensive investigation of water and salt movement has been conducted through field test, laboratory simulation and numerical calculation. The dependence of desalination on irrigation water quantity, drainage quantity, leaching time and other parameters is obtained based on the field tests. The entire desalination process under the flood-irrigation and well-drainage operations was experimentally simulated in a vertical soil column. The water and salt movement has been numerically analysed for both the field and laboratory conditions. The present work indicates that this new technology can greatly improve the effects of desalination.

The Affects of acid mine drainage on the water quality, and benthic macroinvertebrate and fish population in streams in Maryland

The purpose of this study was to measure and evaluate relationships between populations of benthic macroinvertebrates and fish, as well as variations in water quality in streams affected by acid Mine drainage. (PDF contains 21 pages)

Lessons learnt about water use, harvesting, recycling and drainage

This Information Paper is the third in a four-part series that looks at the lessons learnt from the BRE Innovation Park concerning compliance with the Code for Sustainable Homes published in November 2006. It focuses on water use, harvesting, recycling and drainage. The other parts deal with: building fabric; energy sources, overheating and ventilation; architecture, construction and sourcing.

The four national taps of Singapore: a holistic approach to water resources management from drainage to drinking water

 Water resources in Singapore are managed following the principles of a closed loop hydrologic cycle by one agency, the Public Utility Board (PUB), which promotes its management philosophy through the Four National Taps of Singapore program. The four national taps are: water from local catchment areas; imported water (from Malaysia); reused water (known as NEWater); and desalinated water. Given the uncertainty of water imports, the remaining three national taps have become increasingly important and this paper begins with a general overview of the innovative programs implemented by PUB in support of these three taps. Stormwater runoff is captured from two-thirds of Singapore’s land area and stored in reservoirs for subsequent use. Stormwater management is an important component of the catchment area tap and extensive low impact development (LID) implementation has become a priority through the ABC (Active, Beautiful, Clean) Waters Program. Examples of several ABC Waters projects are discussed. NEWater currently supplies 30% of the country’s demand and this is projected to increase to 50% by 2060. NEWater plants take treated wastewater through the additional steps of microfiltration, reverse osmosis and ultraviolet treatment for use primarily in industry, although a portion also is blended into the municipal reservoirs. Singapore’s single desalination plant currently meets 10% of its demand, with a second plant to be completed in 2013 that will more than double production. Also discussed are the results of recently completed pilot projects related to stormwater management including testing of E. coli in runoff from high density residential areas, a blind taste test and survey on acceptance of NEWater, and a survey of Singaporean understanding about stormwater management issues.Water resources in Singapore are managed following the principles of a closed loop hydrologic cycle by one agency, the Public Utility Board (PUB), which promotes its management philosophy through the Four National Taps of Singapore program. The four national taps are: water from local catchment areas; imported water (from Malaysia); reused water (known as NEWater); and desalinated water. Given the uncertainty of water imports, the remaining three national taps have become increasingly important and this paper begins with a general overview of the innovative programs implemented by PUB in support of these three taps. Stormwater runoff is captured from two-thirds of Singapore’s land area and stored in reservoirs for subsequent use. Stormwater management is an important component of the catchment area tap and extensive low impact development (LID) implementation has become a priority through the ABC (Active, Beautiful, Clean) Waters Program. Examples of several ABC Waters projects are discussed. NEWater currently supplies 30% of the country’s demand and this is projected to increase to 50% by 2060. NEWater plants take treated wastewater through the additional steps of microfiltration, reverse osmosis and ultraviolet treatment for use primarily in industry, although a portion also is blended into the municipal reservoirs. Singapore’s single desalination plant currently meets 10% of its demand, with a second plant to be completed in 2013 that will more than double production. Also discussed are the results of recently completed pilot projects related to stormwater management including testing of E. coli in runoff from high density residential areas, a blind taste test and survey on acceptance of NEWater, and a survey of Singaporean understanding about stormwater management issues.

Metal fluxes at the sediment-water interface in rivers in the Turvo/Grande drainage basin, So Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)