Interactions between soil texture and placement of dairy slurry application: II. Leaching of phosphorus forms

Managing phosphorus (P) losses in soil leachate folllowing land application of manure is key to curbing eutrophication in many regions. We compared P leaching from columns of variably textured, intact soils (20 cm diam., 20 cm high) subjected to surface application or injection of dairy cattle (Bos taurus L.) manure slurry. Surface application of slurry increased P leaching losses relative to baseline losses, but losses declined with increasing active flow volume. After elution of one pore volume, leaching averaged 0.54 kg P ha(-1) from the loam, 0.38 kg P ha(-1) from the sandy loam, and 0.22 kg P ha(-1) from the loamy sand following surface application. Injection decreased leaching of all P forms compared with surface application by an average of 0.26 kg P ha(-1) in loam and 0.23 kg P ha(-1) in sandy loam, but only by 0.03 kg P ha(-1) in loamy sand. Lower leaching losses were attributed to physical retention of particulate P and dissolved organic P, caused by placing slurry away from active flow paths in the fine-textured soil columns, as well as to chemical retention of dissolved inorganic P, caused by better contact between slurry P and soil adsorption sites. Dissolved organic P was less retained in soil after slurry application than other P forms. On these soils with low to intermediate P status, slurry injection lowered P leaching losses from clay-rich soil, but not from the sandy soils, highlighting the importance of soil texture in manageing P losses following slurry application.     

Interactions between soil texture and placement of dairy slurry application: I. Flow characteristics and leaching of nonreactive components

Land application of manure can exacerbate nutrient and contaminant transfers to the aquatic environment. This study examined the effect of injecting a dairy cattle (Bostaurus L.) manure slurry on mobilization and leaching of dissolved, nonreactive slurry components across a range of agricultural soils. We compared leaching of slurry-applied bromide through intact soil columns (20 cm diam., 20 cm high) of differing textures following surface application or injection of slurry. The volumetric fraction of soil pores >30 microm ranged from 43% in a loamy sand to 28% in a sandy loam and 15% in a loam-textured soil. Smaller active flow volumes and higher proportions of preferential flow were observed with increasing soil clay content. Injection of slurry in the loam soil significantly enhanced diffusion of applied bromide into the large fraction of small pores compared with surface application. The resulting physical protection against leaching of bromide was reflected by 60.2% of the bromide tracer was recovered in the effluent after injection, compared with 80.6% recovery after surface application. No effect of slurry injection was observed in the loamy sand and sandy loam soils. Our findings point to soil texture as an important factor influencing leaching of dissolved, nonreactive slurry components in soils amended with manure slurry.     

Chemical and microbiological examination of well and Nile water

The chemical composition and microbiological contamination of well water and Nile River water used for drinking were investigated in localities around Khartoum, Sudan, to present baseline data. The chemical analyses results obtained indicated that public health hazards due to pH, Ca⁺⁺, CO₃^??, HCO₃^?, and NO₃^? are unlikely in all the samples studied, while Na⁺ and Cl^? ions concentrations in well water warrant some attention. Contamination from organic matter and suspended material is also negligible. Microbial contamination with coliform and fecal coliform is high in surface wells and in the Nile River, but negligible in deep bores, tap water, and mineral water. The logarithm of the colony count ranges from zero for mineral water to 6.8 for water from the White Nile. In addition to drawing further attention to the well water and Nile water used for drinking by a wide sector of the population, the microbial count data for water from the Nile disagreed with the generally held belief that the Nile, being one of the largest rivers of the world, carries no detectable fecal contamination. Our data also did not support the belief that the White Nile is more contaminated than the Blue Nile.     

Will ASEAN countries be a potential choice for the export of pollution intensive goods?

Environmental Science and Pollution Research - China, being the world’s largest exporter, has now certain environmental commitments such as to achieve carbon neutrality before 2060. These...     

Electrochemical reduction of carbon dioxide into valuable chemicals: a review

Environmental Chemistry Letters - Global warming is partly caused by massive emissions of carbon dioxide (CO2), a greenhouse gas, in the atmosphere by industrial and other human activities....     

Cost-effective treatment of sludge conditioning using supernatant fluid polyelectrolyte

Environmental Science and Pollution Research - Treatment of activated sludge using pure polyelectrolyte and its supernatant fluids for sludge dewatering was examined. The supernatant was used for...     

Radiant Domestic Combustion Stove System: Experimental and Simulated Study of Energy Use and Thermal Comfort

A steady-state space radiant heat model and a stove combustion model are developed to simulate the heat exchanges between various surfaces in the room and the stove and stack surfaces, assuming stiochiometric combustion inside the stove and the exhaust gases flow out through the stack by natural convection. The space heat model calculates the fuel consumption, the stove, stack temperatures, and the mass flow rate of exhaust gases, and provides an opportunity to study the energy efficiency of the stove, while satisfying the constraints of thermal comfort. Fanger (1982) Fanger, P. O. 1982. Thermal Comfort Analysis and Applications in Engineering, 156–198. New York: McGraw Hill.  [Google Scholar] model and a radiation exchange model between various surfaces of the space, the thermal building energy balance, and stove combustion process is applied to determine the mean radiant temperature (MRT) and the extent of thermal comfort as determined by predicted mean vote (PMV).

The overall model is validated by performing experiments in a room placed inside a controlled outdoor environment. The room is heated using a domestic stove common for rural areas of Lebanon and the MRT, the room air temperature, the walls and window temperatures are measured at two stove positions. The measured MRT, the average room temperature, and the wall surface temperatures agreed within ±7% of values predicted by the numerical model.

A parametric study is performed to optimize the stove and occupant locations in the room where adequate comfort level can be maintained at lower fuel consumption levels. The values of MRT and PMV depend strongly on the position of the radiant stove heater and stack with respect to the cold window and the occupant location. It is shown that it is possible to save up to 15% in stove fuel consumption by changing the stove position in the room with respect to the window and to the person, while maintaining the same level of comfort.     

Carbon, nitrogen, and phosphorus distribution in particle size-fractionated separated pig and cattle slurry

Solid liquid separation of animal slurry is a method to reduce the excess nutrient loads from intensive livestock production. Five different separation technologies (sedimentation, centrifugation, pressurized filtration, polymer flocculation and drainage, and iron chloride addition + polymer flocculation and drainage) were applied to pig and cattle slurry in a laboratory study. Separation efficiencies of mass, dry matter (DM), N, and P were measured. Particle size fractionation of the solid fractions was performed by subjecting them to wet fractionation and C, organic N (N(org)), and P contents were subsequently measured. Chemical pretreatment with polymer before gravity drainage separated DM, total N, and P from raw pig and cattle slurry with the highest efficiencies. Sedimentation and centrifugation separated P from pig and cattle slurries with higher simple separation efficiencies (0.77 and 0.70, respectively) compared with pressurized filtration (0.15 and 0.37). Pressurized filtration transferred the lowest masses (14 and 18%) to the solid fractions. Solid fractions from pig slurry generally contained higher concentrations of P and C compared with cattle slurry solid fractions. The majority of C in solid fractions was present in particles > 25 microm, whereas N and P were present in larger proportions in particles < 25 microm. Chemical pretreatment increased the capture of smaller N(org)- and P-rich particles into larger particles between 25 and 1000 microm.     

Do voluntary pollution reduction programs (VPRs) spur or deter environmental innovation? Evidence from 33/50

We study whether a government-sponsored voluntary pollution reduction program (VPR) promotes or deters the development of new environmental technologies that yield future emission reduction benefits. Using a panel of 127 U.S. manufacturing industries defined by 3-digit SIC classifications over the 1989–2004 period, we estimate impacts of industry-level participation in the 33/50 program, a VPR initiated by government regulators in 1991, on industry-level rates of environmental patenting. We find that higher rates of 33/50 program participation are associated with significant reductions in the number of successful environmental patent applications five to nine years after the program ended.     

Particulate matters and gaseous pollutants in indoor environment and Association of ultra-fine particulate matters (PM1) with lung function

Environmental Science and Pollution Research - Real-time particulate matters (PM1, PM2.5, PM4, PM7, PM10, and TSP) with AEROCET 531S (USA), gaseous pollutants (NO2 and TVOC) with Aeroquel 500 gas...