The development of alum rates to enhance the remediation of phosphorus in fluvial systems following manure spills

Following the remediation of animal manure spills that reach surface waters, contaminated streambed sediments are often left in place and become a source for internal phosphorus (P) loading within the stream in subsequent flow. The objective of this study was to develop treatment rates and combinations of alum and CaCO(3) to mitigate P from contaminated sediments of different particle size distributions following a manure spill. Sediment specific alum and CaCO(3) treatment rates were developed based upon the resultant alum treatment ranges established for each sediment type. Clay loam sediments required 54% more alum to mitigate P desorption relative to sediments that contain at least 60% sand. Amending sediments with the highest rates of alum/alum + CaCO(3), resulted in a 98-100% reduction in P desorption and a similar water column pH for all sediments types. Observations from this study demonstrated the effectiveness of alum/alum + CaCO(3) to increase P retention in sediments following a manure spill.     

Control of Organic Emissions from Surface Coating Operations

ABSTRACT

Step tracer tests were carried out on lab-scale biofilters to determine the residence time distributions (RTDs) of gases passing through two types of biofilters: a standard biofilter with vertical gas flow and a modified biofilter with horizontal gas flow. Results were used to define the flow patterns in the reactors. “Non-ideal flow” indicates that the flow reactors did not behave like either type of ideal reactor: the perfectly stirred reactor [often called a "continuously stirred tank reactor" (CSTR)] or the plug-flow reactor.

The horizontal biofilter with back-mixing was able to accommodate a shorter residence time without the usual requirement of greater biofilter surface area for increased biofiltration efficiency. Experimental results indicated that the first bed of the modified biofilter behaved like two CSTRs in series, while the second bed may be represented by two or three CSTRs in series. Because of the flow baffles used in the horizontal biofilter system, its performance was more similar to completely mixed systems, and hence, it could not be modeled as a plug-flow reactor. For the standard biofilter, the number of CSTRs was found to be between 2 and 9 depending on the airflow rate. In terms of NH₃ removal efficiency and elimination capacity, the standard biofilter was not as good as the modified system; moreover, the second bed of the modified biofilter exhibited greater removal efficiency than the first bed. The elimination rate increased as biofilter load increased. An opposite trend was exhibited with respect to removal efficiency.     

State and Local Air Pollution Control Agency Salary Levels—1971

This paper is an examination of the range of salary levels of state, local, and multijurisdictional air pollution control agencies for specific occupational categories. It is based on a manpower and training survey of such agencies conducted by the Office of Air Programs of the Environmental Protection Agency during 1971. Since inadequate salaries have been identified as a primary obstacle in staffing air pollution control agencies, an analysis of salary levels was among the focal points for the survey.

Salaries were found to vary according to occupational category, type of agency, and size of agency. In most instances, salary levels increase as the size of the agency increases. Mean starting salaries have risen significantly since 1968, and salaries for chemists and engineers are becoming more competitive with salaries in private industry.     

Soiling of Building Materials

Six building materials were exposed at five sites in Birmingham, Alabama, to determine the rates of soiling by different levels of suspended particulate. The exposed materials were (1) painted cedar siding, (2) concrete block, (3) brick, (4) limestone, (5) asphalt shingles, and (6) window glass. Suspended particulate levels ranged from an annual geometric mean of 60 μg/m³ at the clean site to 250 μg/m³ at the most polluted site.

Degrees of soiling were determined by measuring reflectance from the opaque surfaces and haze through the glass. Excellent dose-response relationships were obtained for the white surfaces— painted cedar siding and asphalt shingles. The degree of soiling of the paints was directly proportional to the square root of the suspended particulate dose. The shingle soiling was directly proportional to the dose. These regression equations can account for from 74 to 92% of the variability in reflectance measurements.

Similar regressions for brick can account for from 34 to 50 % of the variability. Poor correlations were obtained for concrete, limestone, and window glass.     

Isokinetic Sampler for Continuous Airborne Aerosol Measurements

For aerosol measurements, especially those concerned with the aerosol particle size distribution, it is important to sample in isokinetic conditions. Most available instrumentation for aerosol measurements is intended for use on the ground under light wind conditions; intake air speeds rarely exceed a few meters per second. If the same instrumentation is used onboard an aircraft, the air must be decelerated 60 or more m/sec before It is sampled by individual instruments.

On The Pennsylvania State University Meteorology research aircraft, the air for all aerosol instruments is decelerated in a single isokinetic sampler located above the roof of the cabin outside the aircraft boundary layer. The air enters the sampler through a carefully designed circular intake. Its velocity is reduced as the cross section increases along a 7° conical diffuser. The expansion cone terminates in a cylindrical chamber in which the air velocity is 1/16 the aircraft speed. Behind the sampling chamber the air is accelerated in a second conical section to an end exhaust port. Exhaust porf "pumping" is used to compensate internal losses and, thus, helps preserve the isokinetic nature of the sampler.

Tubes leading to individual instruments are located in the sampling chamber and may be individually adapted to match the air sampling velocity with the local air speed inside the sampling chamber. The level of turbulence (u_rms/û) in the sampling section is =^0.05.

The sampler has been thoroughly wind tunnel and flight tested and successfully used in August and November, 1974, for field programs in the St. Louis and Tucson metropolitan areas, respectively.     

Fine Particulate Organic Material in the Los Angeles Basin - I: Assessment of the High-Volume Brigham Young University Organic Sampling System,BIG BOSS

ABSTRACT

A multi-system, high-volume, parallel plate diffusion dénuder Brigham Young University Organic Sampling System (BIG BOSS) was tested using collocated samplers at the Pico Rivera Monitoring Station of the South Coast Air Quality Management District, South Coast Air Basin, in September 1994. Six-hr daytime and 9-hr nighttime samples were collected with a flow of about 200 L/min through each of the three systems designed to collect particles smaller than 2.5, 0.8, and 0.4 mm in a diffusion denuder sampler. Efficiency for the removal of gas phase organic compounds by the diffusion denuder was evaluated using both theoretical predictions and field measurements. Both measured and calculated data indicate high denuder efficiency for the removal of gas phase aromatic and paraffinic compounds. The precision of the BIG BOSS was evaluated using collocated samplers. The precision of determination of total carbon and elemental carbon retained by a quartz filter or of semi-volatile carbonaceous material lost from particles during sampling averaged ±7%. The precision of determination of individual organic compounds averaged ±10%. An average of 42 and 62% of the particulate organic material was semi-volatile organic compounds (SVOCs) lost from particles during sampling for daytime and nighttime samples, respectively. This “negative” sampling artifact was an order of magnitude larger than the “positive” quartz filter artifact due to adsorption of gas phase organic material. Daytime concentrations of fine particulate elemental carbon and nonvolatile organic carbon were higher than nighttime concentrations, but nighttime fine particles contained more semi-volatile organic material than daytime.     

Odor Determination Techniques for Air Pollution Control

Abstract

An airborne lidar was used to study the smoke plume from the burning of a controlled oil spill on the ocean. The ratio of the amount of light (at a wavelength, λ, of 0.532 u.m) backscattered by the smoke to the amount of light extinguished by the smoke was determined by measuring the strength of a laser beam after it had passed through the smoke plume, been reflected from the ocean, and passed through the smoke plume again, and comparing this to the strength of the laser beam reflected directly from the ocean. The optical depth of the smoke (at λ = 0.532 µm) was typically between 0.2 and 0.5. The mass fluxes of smoke particles that passed through four vertical cross sections of the (nonsteady state) smoke plume were estimated from lidar measurements to be 142, 175, 423, and 414 g ^s-1, compared to an average smoke mass production rate of ~770 g s^-1. The spatial distribution of smoke mass along the long axis of the plume was also estimated from the lidar measurements; derived smoke mass concentrations were generally <300 µg ^m-3, with a few isolated values up to ~800 µg ^m-3.     

Sorption influenced transport of ionizable pharmaceuticals onto a natural sandy aquifer sediment at different pH

The pH-dependent transport of eight selected ionizable pharmaceuticals was investigated by using saturated column experiments. Seventy-eight different breakthrough curves on a natural sandy aquifer material were produced and compared for three different pH levels at otherwise constant conditions. The experimentally obtained K_OC data were compared with calculated K_OC values derived from two different log K_OW-log K_OC correlation approaches. A significant pH-dependence on sorption was observed for all compounds with pK_a in the considered pH range. Strong retardation was measured for several compounds despite their hydrophilic character. Besides an overall underestimation of K_OC, the comparison between calculated and measured values only yields meaningful results for the acidic and neutral compounds. Basic compounds retarded much stronger than expected, particularly at low pH when their cationic species dominated. This is caused by additional ionic interactions, such as cation exchange processes, which are insufficiently considered in the applied K_OC correlations.     

Elevated biogenic sulphur dioxide concentrations over the North Atlantic

Elevated biogenic SO₂ from the oxidation of dimethylsulphide (DMS) in the marine atmosphere was measured over the North Atlantic Ocean in spring and summer 2003. Stable isotope apportionment was used to distinguish between anthropogenic and biogenic SO₂ in the marine atmosphere south of Greenland. Atmospheric DMS measurements were within range of previous studies. Biogenic SO₂ concentrations were as high as 82 nmol m^?3 (spring geometric mean: 4 nmol m^?3, σ = 17; summer geometric mean 7 nmol m^?3, σ = 19) and are the highest reported values for marine biogenic SO₂ in the literature. Elevated biogenic SO₂ was found in air masses influenced by anthropogenic pollutants during the summer. This indicates that anthropogenic pollutants may affect the fate of oceanic emissions of sulphur compounds in the atmosphere favoring the formation of cloud condensation nuclei.