James Rodgers

Immobilization of heavy metal ions (CuII, CdII, NiII, and PbII) by broiler litter-derived biochars in water and soil.

Chars, a form of environmental black carbon resulting from incomplete burning of biomass, can immobilize organic contaminants by both surface adsorption and partitioning mechanisms. The predominance of each sorption mechanism depends upon the proportion of organic to carbonized fractions comprising the sorbent. Information is currently lacking in the effectiveness of char amendment for heavy metal immobilization in contaminated (e.g., urban and arms range) soils where several metal contaminants coexist. The present study employed sorbents of a common biomass origin (broiler litter manure) that underwent various degrees of carbonization (chars formed by pyrolysis at 350 and 700 degrees C and steam-activated analogues) for heavy metal (Cd(II), Cu(II), Ni(II), and Pb(II)) immobilization in water and soil. ATR-FTIR, (1)H NMR, and Boehm titration results suggested that higher pyrolysis temperature and activation lead to the disappearance (e.g., aliphatic -CH(2) and -CH(3)) and the formation (e.g., C-O) of certain surface functional groups, portions of which are leachable. Both in water and in soil, pH increase by the addition of basic char enhanced the immobilization of heavy metals. Heavy metal immobilization resulted in nonstoichiometric release of protons, that is, several orders of magnitude greater total metal concentration immobilized than protons released. The results suggest that with higher carbonized fractions and loading of chars, heavy metal immobilization by cation exchange becomes increasingly outweighed by other controlling factors such as the coordination by pi electrons (C=C) of carbon and precipitation.

Near Infrared Measurement of Cotton Fiber Micronaire by Portable Near Infrared Instrumentation

In the U.S.A., cotton is classed (primary quality parameters) by the Uster ® High Volume Instrument (HVI), which must be maintained under tightly controlled laboratory environmental conditions. Improved and fast response quality measurement systems and tools are needed to rapidly assess the quality of cotton. One key area of emphasis and need is the development and implementation of new fast-response quality measurements that can be used not only in the laboratory but which also can be adapted to field and at-line quality measurements. A program was implemented to determine the ability of portable near-infrared (NIR) instrumentation to monitor critical fiber properties of cotton samples in the laboratory, at-line, and in the field, with initial emphasis on the laboratory measurement of cotton fiber micronaire. Micronaire is a key cotton property, and it is an indicator of the fiber’s maturity and fineness. Distinct NIR spectral differences between samples with varying micronaire were observed. A comparative evaluation was performed to determine optimum instrumental conditions for laboratory cotton micronaire measurements. The comparative evaluation established that the optimum instrumental conditions for laboratory measurements of micronaire was obtained with the use of a glass-covered sampling port and increased instrumental gain, with high R 2 values, low residuals, and with ≤ 12% outliers. For a NIR measurement with potential for multiple simultaneous analyses and non-laboratory measurements, the micronaire measurement was fast (< 3 min per sample) and easy to perform. The rapid and accurate laboratory measurement of cotton fiber micronaire with portable NIR instrumentation was demonstrated.

A rapid measurement for cotton breeders of maturity and fineness from developing and mature fibers

The Cottonscope simultaneously measures a cotton fiber’s maturity and fineness using a small amount of fiber sample. A program of testing was devised to establish the potential and capabilities of the Cottonscope to rapidly and accurately measure maturity and fineness of small quantities of near-isogenic cotton lines (NILs), and to examine the use of the Cottonscope maturity distributions for breeder applications. Cottonscope measurements were performed on mature and immature fibers of varying days post-anthesis (DPA) from two pairs of NILs (MD 52ne versus MD 90ne; TM-1 versus the low maturity im). The patterns of cotton maturity and fineness during cotton fiber development of each NIL measured by the Cottonscope were compared to those measured by more conventional methods (e.g. the Advanced Fiber Information System (AFIS), an older and currently more widely used method). The Cottonscope maturity and fineness results were much more responsive to increasing DPA than the AFIS results, and the patterns of Cottonscope maturity values were consistent with those of the Fibronaire micronaire. Comparisons of the Cottonscope maturity distributions among the NILs demonstrated that the maturity distribution for im was very different and exhibited much lower maturity values compared to the distributions of other lines. The results demonstrated that the Cottonscope is an efficient instrument for cotton breeders to monitor fiber maturity and fineness of developing and mature cotton fibers.

Understanding the influence of fiber length on the High Volume Instrument™ measurement of cotton fiber strength

An earlier study confirmed the influence of cotton fiber length characteristics on the High Volume Instrument™ (HVI) strength measurement and devised a quantitative correction factor to compensate for the effect. The current paper investigated the validity of two important assumptions utilized in the previous study. Firstly, single fiber testing confirmed that the particular sample preparation method used to generate samples of different fiber length characteristics from a common cotton sliver did not introduce any inherent damage to the fibers (and so this could not be the explanation for the observed trend in measured fiber strength as a function of fiber length). Secondly, the positioning of the jaws relative to the beard in the HVI strength measurement was explored. This positioning was found to be quite variable for replicate measurements on the same cotton being a function of the size of each individual beard. The average positioning between the different samples was found to be similar and this validated the assumption and approach used previously for deriving the correction factor for that particular sample set. Characterizing the position of the jaws was extended using a wider range of cotton samples. The HVI positioning algorithm appears to not simply be a function of the size of the beard (i.e. the ‘amount’ parameter), but is also dependent on fiber length characteristics. It was also observed that the reported HVI elongation values displayed both a significant bias due to fiber length and also a dependence on the size of individual beards tested.

New Approaches for Field Analyses of Cotton Quality by Means of Near-IR Spectroscopy Supported by Chemometrics

There is a strong economic interest in routine measurements of cotton quality as production processes and final products depend on it. An important cotton property is “micronaire,” a parameter that is indicative of the fibers maturity and its fineness. Currently, micronaire is normally measured in laboratories with equipment that prohibits routine field analyses. The goal of this study is a proof-of-principle demonstrating that cotton quality as determined via fiber micronaire is correlated to fiber properties and that these properties can be determined by near-infrared (NIR) reflection spectroscopy using portable instrumentation in conjunction with Principal Component Regression for micronaire prediction. A set of 191 cotton samples was acquired from over 100 different upland cotton varieties, and initial spectroscopic studies confirmed the feasibility of NIR spectroscopy to measure cotton micronaire in the laboratory with portable NIR instrumentation. Sample reproducibility was an issue which has been resolved with two approaches, that is, model spectral artifacts, mainly baseline shifts, by means of chemometric calibrations or application of second derivative spectroscopy to suppress baseline drifts. Results from this study demonstrated in up to 90% of the test samples that the micronaire values fall into the acceptance range. Thus, a promising new approach for field analyses is on the horizon and has been assessed in this study. Further, the acceptance range could be reduced to ±0.2 m.u. and still ≥70% of the samples fell inside the restricted acceptance range. Up to 60% of the samples fell inside an acceptance range of ±0.1 m.u.

Preliminary evidence of oxidation in standard oven drying of cotton: attenuated total reflectance/Fourier transform infrared spectroscopy, colorimetry, and particulate matter formation:

Currently, oven drying in air is often utilized to generate the percentage of moisture in cotton fibers. Karl Fischer Titration, another method for cotton moisture measurement, has been compared to the oven drying method. The percentage of moisture as generated by the oven method tracks those of Karl Fischer Titration, but there are differences between the two. In fact, a bias exists in the measured moisture loss employing the standard oven drying method. In addition, the moisture data collected via Karl Fischer Titration demonstrates smaller variances than those data collected in the oven. The aim of this study is to determine what is causing those differences. In the current report, particulate matter formation and browning of oven-treated cotton samples have been observed, suggesting visible indirect evidence that cotton oxidation may be occurring. It is noteworthy that three types of oxidation processes may be occurring during the current study: heating in air, scouring and bleaching, and periodate-driven processes. The first two oxidative processes yield non-specific products, whereas the periodate-driven oxidative products are well-defined in the literature. Thus, a method was needed to gain direct evidence for this postulated cotton oxidation that may be contributing to the bias in the standard oven drying method used to calculate moisture loss in cotton. Thus, this preliminary study employed Attenuated Total Reflectance/Fourier Transform Infrared spectroscopy to determine if direct evidence for oxidation can be observed for oven-treated cotton samples.

Preliminary study of relating cotton fiber tenacity and elongation with crystallinity

A fundamental understanding of the relationship between cotton fiber strength (or tenacity)/elongation and structure is important to help cotton breeders modify varieties for enhanced end-use qualities. In this study, the Stelometer instrument was used to measure the bundle fiber tenacity and elongation properties of different cotton fibers. This instrument is the traditional fiber strength reference method and could be still preferred as a screening tool owing to its significant low cost and portability. Fiber crystallinity (CIIR) and maturity (MIR) were characterized by the previously proposed attenuated total reflection (ATR)-based Fourier transform infrared protocol that has microsampling capability and is suitable for the tiny Stelometer breakage specimens (2u2009∼u20095u2009mg), which cannot be readily analyzed by a conventional X-ray diffraction pattern. Relative to the distinctive increase in fiber tenacity with either CIIR or MIR for Pima fibers (Gossypium barbadense), there was an unclear trend between the two for Upland fibers (G. hirsutum). Although fiber elongation increases with elevated CIIR and MIR for Pima fibers, it generally decreases as CIIR and MIR increase for Upland fibers. Furthermore, small sets of Upland fibers with known varieties and growth areas were examined, and their responses to both CIIR and MIR are discussed briefly.