The present paper deals with the simultaneous removal of Pyridine (Py), $\alpha$ -picoline $\left(\alpha \text{Pi}\right)$ , and $\gamma$ -picoline $\left(\gamma \text{Pi}\right)$ from aqueous solutions by sorption onto rice husk ash (RHA) and granular activated carbon (GAC). Optimal design of experiments using Taguchi’s methodology has been applied to study the effects of various parameters, viz adsorbent dose, initial pH, contact time, initial concentrations, and temperature on the simultaneous removal of Py, $\alpha \text{Pi}$ , and $\gamma \text{Pi}$ . $3^{13}$ orthogonal array of Taguchi design has been used for parameter optimization for the sorption $\left(q_{\text{tot}}\right)$ of Py, $\alpha \text{Pi}$ and $\gamma \text{Pi}$ , by RHA and GAC. The ANOVA shows that the initial concentration of $\alpha \text{Pi}$ is the most significant parameter with 27.6% and 27.8% contribution to the $q_{\text{tot}}$ for raw and signal-to-noise (S/N) ratio data, respectively, for RHA. For GAC, the adsorbent dose $\left(m\right)$ is the most significant parameter with 32.2% and 17.5% contribution to the $q_{\text{tot}}$ for raw and S/N ratio data, respectively. The interactions between initial concentrations also contribute significantly to the overall sorption. Using the optimum conditions obtained by Taguchi’s experimental design, the respective percent removal of Py, $\alpha \text{Pi}$ , and $\gamma \text{Pi}$ was found to be $\sim 49$ %, $\sim 71$ %, and $\sim \mathrm{88\%}$ by RHA, and $\sim 42\%$ , $\sim 61\%$ , and $\sim 71\%$ by GAC. The spent RHA and GAC can be used as fuels in furnaces.

Phytoextraction is an ecofriendly technology through which plants are used for removing heavy metal contaminant from polluted sites. The effective implementation of this cost effective emerging technology requires a conceptual insight of soil and plant processes that control the uptake of targeted contaminant from the problematic area. Most of the current research deals with the plants grown in heavy metal contaminated soils and analyzed experimentally to determine their capacity to remove them from the soil. However, the prediction of the metal uptake by plants through mathematical modeling has received very little attention so far due to the complexity of the soil-plant-atmosphere continuum. In this study, a mathematical model is developed to investigate the removal of a heavy metal, lead (Pb), by maize at different growth stages of the plant. The model comprised of two parts: (1) moisture flow prediction and (2) contaminant uptake simulation. The first part predicts the actual water uptake by plant and computes the hydraulic regime of the soil profile for different moisture conditions. Through the second part of the model, the lead extraction kinetics is simulated using the water uptake data and plant root biomass accumulation. The model yields a set of partial differential equations which are solved numerically by the finite difference technique for varying boundary conditions. The moisture flow simulation is validated using the literature of field data for maize and the metal extraction simulation is performed based on this prediction for a characteristic example to remediate a lead contaminated site.

Large quantities of coal ashes are being produced by coal fired thermal power plants all over the world. Because of some of their inherent properties, the coal ashes are proving to be potential hazardous materials causing environmental pollution. The need of the day is to have practical engineering applications which involve the safe disposal of such so considered hazardous materials. Coal ashes have been shown to have advantageous properties such as low specific gravity, lower compressibility, higher rate of consolidation, high strength, high California Bearing Ratio, high volume stability, water insensitiveness to compaction, and pozzolanic reactivity. Coal ashes can be used as better alternative materials of construction in addition to their bulk use in the field of Geotechnical Engineering. Geotechnical Engineering Practice helps in the safe and effective disposal of coal ashes in bulk in a more ecofriendly way.

Methods for the measurement and analysis of asbestos and other fibers in air, water, dust, and bulk materials vary by type of scenario and according to applicable laws and rules. Two surveys and a focus group were used to identify the most important information gaps in asbestos exposure assessments. The highest priority gaps were identifying analytical procedures and counting rules needed for asbestos detection; comparing the efficiency of 0.45-micron pore size filters versus 0.8-micron pore size filter media; rating the efficiency of polycarbonate versus mixed cellulose ester filters, and the need for bench-level testing of filters to evaluate fiber collection performance of these filter media. Other key responses included the need for consistency of analytical procedures and counting rules to determine suitable procedures for asbestos detection and quantitation in bulk samples, air, settled dust, and soil for field monitoring and risk analysis; need to identify underlying factors and physical dynamics that lead to aerosolization of fibers from bulk materials in various exposure pathways. The pore size of filters used in collecting fibers was identified as a key asbestos measurement uncertainty. Thus, a study is recommended to compare postpreparation asbestos fiber retention on mixed cellulose ester and polycarbonate filters.

Full-scale high-density polyethylene pipes of external diameter 0.05 and 0.1 m, and internal diameter 0.04 and 0.08 m, were permeated with leachate to characterize the changes in select leachate constituents within the pipes for three different flow rates (0.25, 0.55, and 1.2 L/s). Chemical oxygen demand of 10 to 25% and calcium removal of 25 to 50% occurred within the pipes for each flow rate tested. After 5 months of operation, clog material accumulated within the pipe contained on average 40 and 45% of volatile and inorganic solids, respectively, indicating that biological and mineral solids contributed to pipe clogging. Hydromagnesite $\left({\text{Mg}}_5{\left({\text{CO}}_3\right)}_4{\left(\text{OH}\right)}_{2}4{\text{H}}_2\text{O}\right)$ was the mineral component of the inorganic solids. For all other conditions being generally equal, after 5 months of operation, the 0.08-m internal diameter pipes accumulated more clog mass than the 0.04-m internal diameter pipes. However, the 0.04-m diameter pipes experienced a greater reduction in cross section area for fluid flow than the 0.08-m diameter pipes. Thus, smaller diameter pipes may experience quicker reduction in hydraulic performance than larger pipes for all other conditions being equal.

Thermoplastic rejects are unrecyclable plastics that are often burned causing harmful emissions. Foundry sand waste is a hazardous waste that poses significant health risks. This paper investigates the mechanical and environmental properties of thermoplastic rejects reinforced with foundry sand waste. The thermoplastic rejects were reinforced with foundry sand waste at different percentages of 10, 20, and 30% reinforcement. Regular sand was also used as a reinforcing material to be compared with the properties of foundry sand waste at these percentages. It was shown that thermoplastic rejects reinforced with foundry sand waste at 10% reinforcement had significant improvements to the mechanical properties of the material. Two different machining methods of milling and rolling were analyzed and found that the rolling method allowed for better tensile strengths of approximately 42% better values and higher ductility. The environmental tests showed that the material did not produce any leachate, and would not corrode under chemicals of high corrosivity. This composite material has increased strength and may be used in suitable applications such as manhole covers, speed bumps, and pavement blocks.

The chitosan-based biocoagulant was developed and applied to reduce the turbidity of superturbid drinking water. After a serial experiment on jar tester and a continuous flow pilot plant it was concluded that the residual turbidity of the treated water can meet the regulated value, i.e., 5 nephelometric turbidity unit easily under an economical condition. In addition to turbidity reduction, an acute oral toxicity study was conducted to evaluate the toxicity of biocoagulant itself and the water after treatment in imprinting control region mice by oral gavage. The experimental results show that no death and treatment-related clinical signals were found in animals within the 14-day study period. There were no differences in bodyweights among all treated and control mice. The results indicate that the developed biocoagulant prevailed over the current chemical coagulants not only on treatment efficiency, but also on biosafety. By applying dual coagulants operation model, the superturbid water can be treated efficiently and economically, under which the water deficiency during typhoon period can be eliminated completely.

Increasing population and advancing technology have been continually consuming natural resources to cause global warming and depletion of water resources. How to raise the efficiency and eliminate unnecessary wastes will assist in conserving precious resources. As the water resource is concerned, water leaking from a single faucet may not be much but considering the number of faucets being used globally, the total amount of water wasted is significant. The objective of this study is to target leaking water faucets in a school for developing a model that can be implemented to evaluate water wasting through leaking faucets. Indices for evaluating the characteristics of leaking faucets are first established; the statistical significance is based for proposing the evaluating procedures followed by developing a set of evaluating model based on the 6-sigma standard deviation measure, analyze, improve and control model for conducting detailed analyses. A leaking loss analysis diagram is then developed according to the leaking evaluation and leaking stability indices in order to facilitate the application of the evaluation process. These two indices are then used to propose a total leaking loss index for evaluating the quality of the evaluation results and improving the evaluation efficiency. Combining the leaking quantity evaluation index, leaking stability index, and leaking frequency index, a three-dimension water saving analysis diagram can be constructed. Through the subsequent analyses, improvement and control, suggestions on the regional quality of leaking loss analyses and experts’ recommendations for improvement can be established for references by schools and public or private sectors to improve water leaking situation. Finally, a control diagram is proposed to improve the accuracy and precision of water leaking improvement for achieving the objective of curbing faucet water leaking. The model proposed in this research can provide guidelines for schools and offices to implement the improvement and evaluate the efficiency of implementing the improvement for achieving savings of energy.