Application of Tabu Search Algorithm With a Coupled AnnAGNPS‐CCHE1D Model to Optimize Agricultural Land Use1

Abstract: A principal contributor to soil erosion and nonpoint source pollution, agricultural activities have a major influence on the environmental quality of a watershed. Impact of agricultural activities on the quality of water resources can be minimized by implementing suitable agriculture land‐use types. Currently, land uses are designed (location, type, and operational schedule) based on field study results, and do not involve a science‐based approach to ensure their efficiency under particular regional, climatic, geological, and economical conditions. At present, there is a real need for new methodologies that can optimize the selection, design, and operation of agricultural land uses at the watershed scale by taking into account environmental, technical, and economical considerations, based on realistic simulations of watershed response. In this respect, the present study proposes a new approach, which integrates computational modeling of watershed processes, fluvial processes in the drainage network, and modern heuristic optimization techniques to design cost effective land‐use plans. The watershed model AnnAGNPS and the channel network model CCHE1D are linked together to simulate the sediment and pollutant transport processes. Based on the computational results, a multi‐objective function is set up to minimize soil losses, nutrient yields, and total associated costs, while the production profits from agriculture are maximized. The selected iterative optimization algorithm uses adaptive Tabu Search heuristic to flip (switching from one alternative to another) land‐change variables. USDA’s Goodwin Creek experimental watershed, located in Northern Mississippi, is used to demonstrate the capabilities of the proposed approach. The results show that the optimized land‐use design with BMPs using an integrated approach at the watershed level can provide efficient and cost‐effective conservation of the environmental quality by taking into account both productivity and profitability.     

Cadmium adsorption and desorption behaviour on goethite at low equilibrium concentrations: effects of pH and index cations

The transport and bioavailability of cadmium is governed mainly by its adsorption-desorption reactions with minerals such as goethite--a common iron oxide mineral in variable charged and highly weathered tropical soils. Soil factors such as pH, temperature, solution Cd concentration, ionic strength and ageing affect Cd adsorption on goethite. The desorption behaviour of Cd from goethite at low concentrations is not fully understood. This study investigates the adsorption-desorption of Cd at low Cd concentrations (Cd adsorbed on goethite from 20 to 300 microM Cd solutions) in Na and Ca nitrate solutions of 0.03 M nominal ionic strengths. Synthetic goethite prepared by ageing a ferric hydroxide gel at high pH and room temperature was used for Cd adsorption and desorption studies. For desorption experiment 10 successive desorptions were made for the whole range of initial Cd concentrations (20-300 microM) in the presence of 0.01 M Ca(NO3)2 or 0.03 M NaNO3 solutions. Cadmium adsorption was found to be higher in Na+ than Ca2+ probably due to the competition of Ca2+ ions with Cd2+ ions for adsorption sites on the surfaces of goethite. The effect of index cation on Cd adsorption diminished with increase in pH from 5.0 to 6.0. Cadmium desorption decreased with increase in pH from 5.0 to 6.0 in both Na and Ca systems. After 10 successive desorptions with 0.03 M NaNO3 at the lowest initially adsorbed Cd approximately 45%, 20% and 7% of the adsorbed Cd was desorbed at pH 5.0, 5.5 and 6.0, respectively. The corresponding desorptions in the presence of 0.01 M Ca(NO3)2 were 49%, 22% and 8%, respectively. The Freundlich parameter, k, based on each progressive step of desorption at different adsorbed concentration increased with increasing desorption step, which may indicates that a fraction of Cd was resistant to desorption. Low Cd desorbability from goethite may be due to its specific adsorption and/or possibly as a result of Cd entrapment in the cracks or defects in goethite structure.     

Efficient removal of tetracycline by CoO/CuFe2O4 derived from layered double hydroxides

Environmental Chemistry Letters - Health concerns have been raised over the excessive occurrences of antibiotics such as tetracycline in aquatic environments. Adsorption is a simple and cheap...     

Ecosystem service lens reveals diverse community values of small-scale fisheries

The ocean provides benefits to coastal communities around the world, however, the depth and complexity of people’s interactions with marine ecosystems are not well represented in many marine management initiatives. Many fisheries are managed to maximize provisioning value, which is readily quantified, while ignoring cultural values. An ecosystem services approach that includes both provisioning and cultural services will enable managers to better account for the diverse values marine fisheries provide to coastal communities. In this study, we assess community values related to a top fished species, the Mexican chocolate clam, Megapitaria squalida, in Loreto, Baja California Sur, Mexico. We conducted an exploratory analysis based on 42 household surveys, and found that community members perceive multiple provisioning and cultural benefits from the clam, including community economic, historical, and identity values. Despite reporting infrequent harvest and consumption of clams, participants perceive the species as an important part of community identity, highlighting the role of Mexican chocolate clams as a cultural keystone species in the Loreto region. Fisheries management that recognizes the full range of ecosystem services a species contributes to coastal communities will be better equipped to sustain these diverse values into the future.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01405-w) contains supplementary material, which is available to authorized users.     

Effect of Se sources and concentrations on performance,antioxidant defense,and functional egg quality of laying Japanese quail (Coturnix japonica)

Environmental Science and Pollution Research - The study aimed to investigate the effect of Se sources and concentrations on performance, thyroid activity, antioxidant defense, and functional egg...     

Bioleaching metal-bearing wastes and by-products for resource recovery: a review

The global transition to a circular economy calls for research and development on technologies facilitating sustainable resource recovery from wastes and by-products. Metal-bearing materials, including electronic wastes, tailings, and metallurgical by-products, are increasingly viewed as valuable resources, with some possessing comparable or superior quality to natural ores. Bioleaching, an eco-friendly and cost-effective alternative to conventional hydrometallurgical and pyrometallurgical methods, uses microorganisms and their metabolites to extract metals from unwanted metal-bearing materials. The performance of bioleaching is influenced by pH, solid concentration, energy source, agitation rate, irrigation rate, aeration rate, and inoculum concentration. Optimizing these parameters improves yields and encourages the wider application of bioleaching. Here, we review the microbial diversity and specific mechanisms of bioleaching for metal recovery. We describe the current operations and approaches of bioleaching at various scales and summarise the influence of a broad range of operational parameters. Finally, we address the primary challenges in scaling up bioleaching applications and propose an optimisation strategy for future bioleaching research.

     

Assessment of elemental distribution and heavy metals contamination in phosphate deposits: potential health risk assessment of finer-grained size fraction

The concentrations and chemical distributions of heavy metals (Cd, Cr, Ni, Zn, U, and V) in the Al-Jiza phosphate ores were investigated. Typically, the mean concentration values of Cd, Cr, Ni, U, and Zn are 15 ± 8, 109 ± 21, 34 ± 6, 211 ± 55, 142 ± 55, and 161 ± 57 mg kg^?1, respectively. On the other hand, the encountered average concentration values of Cd, Cr, Ni, Zn, U, and V in the phosphate dust particles (<0.053) were found to be 22 ± 5, 179 ± 5, 67 ± 11, 441 ± 14, 225 ± 58, and 311 ± 9 mg kg^?1, respectively. The contamination factors of U and Cr are greater than 1, indicating that these heavy metals could be potentially hazardous, if released to the environment. Multivariate statistical analysis allowed the identification of three main factors controlling the distribution of these heavy metals and the other chemical constituents. The extracted factors are as follows: francolite mineral factor, clay minerals factor, and diagenesis factor. Health risk assessments of non-cancerous effects in finer-grained size fraction that might be caused by contamination with the heavy elements have been calculated for both children and adults. The risk assessments in case of children for non-cancerous effects showed that U has values greater than the safe level of hazard index (HI = 1). In case of adults, the value of risk for U is also higher as compared to those of Cd, Ni, Cr, and Zn where it lies within the safe range of hazard index (HI < 1). Child health risk assessment indicates that children are more vulnerable to contaminants from phosphate mining than adults.     

Bioclimatic characteristic of oak species Quercus macranthera subsp. syspirensis and Quercus petraea subsp. pinnatiloba in Turkey

This study was carried out to determine some bioclimatic characteristics such as humidity category (Q2), winter variant (m), the length of the dry season (LDS) and the dry season water deficit (DSWD) of naturally growing two endemic oak taxa, Quercus macranthera subsp. syspirensis and Q. petraea subsp. pinnatiloba, living in Turkey. Our findings showed that bioclimatic tolerance range of Q. macranthera subsp. syspirensis possess 7 different types of Mediterranean bioclimate while Q. petraea subsp. pinnatiloba had 8 of them. Although Q. macranthera subsp. syspirensis was ranging among the semiarid, freezing and very cold, Q. petraea subsp. pinnatiloba was among sub-humid, freezing and very cold ambient. It was briefly established that Q. macranthera subsp. syspirensis prefers semi-arid and very cold/freezing conditions and Q. petraea subsp. pinnatiloba prefers sub-humid and cold/very cold climatic conditions.     

A conceptual framework of agricultural land use planning with BMP for integrated watershed management

Land use planning is an important element of the integrated watershed management approach. It not only influences the environmental processes such as soil and stream bed erosion, sediment and nutrient concentrations in streams, quality of surface and ground waters in a watershed, but also affects social and economic development in that region. Although its importance in achieving sustainable development has long been recognized, a land use planning methodology based on a systems approach involving realistic computational modeling and meta-heuristic optimization is still lacking in the current practice of integrated watershed management. The present study proposes a new approach which attempts to combine computational modeling of upland watershed processes, fluvial processes and modern heuristic optimization techniques to address the water-land use interrelationship in its full complexity. The best land use allocation is decided by a multi-objective function that minimizes sediment yields and nutrient concentrations as well as the total operation/implementation cost, while the water quality and the production benefits from agricultural exploitation are maximized. The proposed optimization strategy considers also the preferences of land owners. The runoff model AnnAGNPS (developed by USDA), and the channel network model CCHE1D (developed by NCCHE), are linked together to simulate sediment/pollutant transport process at watershed scale based on any assigned land use combination. The greedy randomized adaptive Tabu search heuristic is used to flip the land use options for finding an optimum combination of land use allocations. The approach is demonstrated by applying it to a demonstrative case study involving USDA Goodwin Creek experimental watershed located in northern Mississippi. The results show the improvement of the tradeoff between benefits and costs for the watershed, after implementing the proposed optimal land use planning.