Bioremediation of residual fertilizer nitrate: II. Soil redox potential and soluble iron as indicators of soil health during treatment

The prospect of using wastewater containing high loads of soluble organic matter (OM) for removing residual agricultural chemicals (fertilizer, pesticide, or herbicide) in farm soil, although promising, could have adverse effects on soil agricultural quality as a result of development of redoximorphic features in the soil profile. In this study, the effect of organic carbon supplement for bioremediation of residual fertilizer nitrate on soil properties, redox potential (Eh), pH, and metal ion mobilization was studied using sandy soils packed in columns. The study was included in a general project, described elsewhere (Ugwuegbu et al., 2000), undertaken to evaluate use of controlled water table management (WTM) systems to supply organic carbon for creating a reduced environment conducive to denitrification of residual fertilizer nitrate leaching from the farm to subsurface water. The columns were subjected to subirrigation with water containing soluble organic carbon in the form of glucose. The work was carried out in two experimental setups and the long-term effect of a range of glucose concentrations on the Eh, pH, and soluble levels of Fe and Mn was investigated. From the results obtained, it could be concluded that excessive organic carbon supplement to soil can have adverse effects on soil quality and that Eh and soluble Fe are the two most practical parameters for monitoring soil health during treatment of farm chemicals.     

Considerations for the design of organic mulch permeable reactive barriers

Organic mulch consists of insoluble carbon biopolymers that are enzymatically hydrolyzed during decomposition to release aqueous total organic carbon (TOC). The released TOC is utilized by microorganisms as an electron donor to transform electrophilic contaminants via reductive pathways. Over the last decade, organic mulch permeable reactive barriers (PRBs), or biowalls, have received increased interest as a relatively inexpensive slow‐release electron donor technology for addressing contaminated groundwater. To date, biowalls have been installed to enhance the passive bioremediation of groundwater contaminated with a variety of electrophilic compounds, including chlorinated solvents, explosives, and perchlorate. In addition, several mulch biowall projects are currently under way at several U.S. Department of Defense facilities. However, at the present time, the guidelines available for the design of mulch PRBs are limited to a few case studies published in the technical literature. A biowall design, construction, and operation protocol document is expected to be issued by the Air Force Center for Environmental Excellence in 2007. In this publication, three technical considerations that can have a significant impact on the design and performance of mulch PRBs are presented and discussed. These technical considerations are: (1) hydraulic characteristics of the mulch bed; (2) biochemical characteristics of different types of organic amendments used as mulch PRB fill materials; and (3) a transport model that can be used to estimate the required PRB thickness to attain cleanup standards. © 2007 Wiley Periodicals, Inc.     

The variability in nutrient composition of Anaerobic Digestate granules produced from high shear granulation

This study investigates the production of organic fertilizer using Anaerobic Digestate (as a nutrient source) and limestone powder as the raw materials. A two-level factorial experimental design was used to determine the influence of process variables on the nutrient homogeneity within the granules. Increasing the liquid-to-solid ratio during granulation resulted in increased granule nutrient homogeneity. Increasing the processing time and the impeller speed were also found to increase the nutrient homogeneity. In terms of nutrients release into deionized water, the granules effectively released both potassium and phosphate into solution.     

Prenatal DNA Sequencing: Clinical,Counseling, and Diagnostic Laboratory Considerations

Clinical diagnostic laboratories are producing next-generation sequencing-based test results that are becoming increasingly incorporated into patient care. Whole genome and exome sequencing on fetal material derived from amniocytes, chorionic villi, or products of conception is starting to be offered clinically in specialized centers, but it has not yet become routine practice. The technical, interpretation, and ethical challenges are greatest in the area of prenatal medicine because the fetus has a limited health history, and the physical examination is only indirectly available via prenatal sonography. Here, we provide an overview of these challenges and highlight the clinical utility, reporting, and counseling issues associated with prenatal DNA sequencing. Future considerations are also discussed. © 2017 John Wiley & Sons, Ltd.     

Measurement of soil radioactivity levels and radiation hazard assessment in southern Rechna interfluvial region, Pakistan

Rechna interfluvial region is one of the main regions of Punjab, Pakistan. It is the area which is lying between River Ravi and River Chenab, alluvial-filled. Radioactivity levels in soil samples, collected from southern Rechna interfluvial region, Pakistan, have been estimated by using gamma-ray spectrometric technique. ²²⁶Ra, ²³²Th, the primordial radionuclide ⁴⁰K, and the artificial radionuclide ¹³⁷Cs have been measured in the soil of the study area. The mean radioactivity levels of ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs were found to be 50.6 ± 1.7, 62.3 ± 3.2, 662.2 ± 32.1, and 3.1 ± 0.3 Bq kg^???1, respectively. The mean radium equivalent activity (Ra_eq), outdoor radiation hazard index (H _out), indoor radiation hazard index (H _in), and terrestrial absorbed dose rate for the area under study were determined as 190.8 ± 8.7 Bq kg^???1, 0.52, 0.65, and 69.8 nGy h^???1, respectively. The annual effective dose to the general public was found to be 0.43 mSv. This value lies well below the limit of 1 mSv for general public as recommended by the International Commission on Radiological Protection. The measured values are comparable with other global radioactivity measurements and are found to be safe for the public and the environment.     

Targeting vulnerability after the 2005 earthquake: Pakistan's Livelihood Support Cash Grants programme

The 7.6 magnitude (Richter scale) earthquake that struck northern Pakistan on 8 October 2005 was devastating. This paper gauges success in targeting vulnerable families during the transition from relief to reconstruction through cash assistance provided by the Livelihood Support Cash Grants (LSCG) programme. Families without a male member, with a disabled male member aged between 18 and 60 years or with more than five children, defined as vulnerable, were provided with USD 50 per month for six months via a bank transfer. The LSCG scheme enrolled around 750,000 families and selected 267,402 vulnerable families to whom it disbursed a total of USD 86.95 million. Using a community‐based survey, this paper assesses leakage and under‐coverage (exclusion). Approximately 30 per cent of families received the cash grant. However, only one in two was eligible for the benefit, and one in two deserving families was excluded. This is a matter of grave concern.     

Leachability and phytoavailability of nitrogen, phosphorus, and potassium from different bio-composts under chloride- and sulfate-dominated irrigation water

Concerns over increased phosphorus (P) application with nitrogen (N)-based compost application have shifted the trend to P-based composed application, but focusing on one or two nutritional elements does not serve the goals of sustainable agriculture. The need to understand the nutrient release and uptake from different composts has been further aggravated by the use of saline irrigation water in the recent scenario of fresh water shortage. Therefore, we evaluated the leachability and phytoavailability of P, N, and K from a sandy loam soil amended with animal, poultry, and sludge composts when applied on a total P-equivalent basis (200 kg ha(-1)) under Cl(-) (NaCl)- and SO4(2-) (Na2SO4)-dominated irrigation water. Our results showed that the concentration of dissolved reactive P (DRP) was higher in leachates under SO(4)(2-) than Cl(-) treatments. Compost amendments differed for DRP leaching in the following pattern: sludge > animal > poultry > control. Maize (Zea mays L.) growth and P uptake were severely suppressed under Cl(-) irrigation compared with SO4(2-) and non-saline treatments. All composts were applied on a total P-equivalent basis, but maximum plant (shoot + root) P uptake was observed under sludge compost amendment (73.4 mg DW(-1)), followed by poultry (39.3 mg DW(-1)), animal (15.0 mg DW(-1)), and control (1.2 mg DW(-1)) treatment. Results of this study reveal that irrigation water dominated by SO4(2-) has greater ability to replace/leach P, other anions (NO3(-)), and cations (K+). Variability in P release from different bio-composts applied on a total P-equivalent basis suggested that P availability is highly dependent on compost source.     

Particleboard manufacturing: an innovative way to recycle paper sludge

This paper presents the results on a study to use paper mill sludge for particleboard production. Single-layer board and three-layer board, with paper sludge on the surface, were fabricated. Four levels of mixing ratios of paper sludge to wood particles (0:100, 15:85, 30:70, and 45:55) were used. The boards were produced with 3% and 4% methylene diphenyl diisocyanate (MDI), and 10% and 12% urea-formaldehyde (UF) adhesives. The bending and shear strengths, water absorption, and thickness swelling of the boards were investigated. The results indicated that the mechanical properties of the boards were negatively affected by the paper sludge amount. Overall, UF-bonded particleboards gave superior mechanical performance, water resistance, and thickness swell than MDI-bonded particleboards. The strengths of the UF-bonded board decreased much more than those of MDI-bonded board as paper sludge content increased. The three-layer boards made from 15% paper sludge with 12% UF satisfied fully the minimum requirements set by EN, ASTM D 1037-99, and ANSI A208.1 standards for general uses.