Microplastics in the benthic invertebrates from the coastal waters of Kochi,Southeastern Arabian Sea

This study examined microplastic particles present in the benthic invertebrates Sternaspis scutata, Magelona cinta (deposit feeders) and Tellina sp. (suspension feeder) from the surface sediments of off-Kochi, southwest coast of India. The microplastic particles and thread-like fibres detected in these organisms were identified to be polystyrene by using DXR Raman microscope. Examination of the microplastic particle in Sternaspis scutata by epifluorescent microscopy showed fragmentation marks on the surface suggesting that the microplastic particle was degraded/weathered in nature. The study provides preliminary evidence of the presence of microplastics in benthic fauna from the coastal waters of India. However, further studies are required to understand the sources, distribution, fate and toxicity of the different types of microplastics in benthic invertebrates in order to identify any potential threats to higher trophic level organisms.     

LivestockPlus: Forages,sustainable intensification,and food security in the tropics

The increased use of grain-based feed for livestock during the last two decades has contributed, along with other factors, to a rise in grain prices that has reduced human food security. This circumstance argues for feeding more forages to livestock, particularly in the tropics where many livestock are reared on small farms. Efforts to accomplish this end, referred to as the ‘LivestockPlus’ approach, intensify in sustainable ways the management of grasses, shrubs, trees, and animals. By decoupling the human food and livestock feed systems, these efforts would increase the resilience of the global food system. Effective LivestockPlus approaches take one of two forms: (1) simple improvements such as new forage varieties and animal management practices that spread from farmer to farmer by word of mouth, or (2) complex sets of new practices that integrate forage production more closely into farms’ other agricultural activities and agro-ecologies.     

大气二氧化硫浓度的光学测定方法

介绍了测定二氧化硫浓度的几种光学方法 ,指出了目前一些化学方法的局限性 ,特别对紫外荧光法的原理、二氧化硫的吸收光谱以及荧光光谱进行分析探讨 ,设计了实验分析系统 ,得出该方法具有操作简单、灵敏度高、可实时在线的智能化优点 ,将会成为今后研究的主导方向。     

Co-present Pb(II) accelerates the oxidation of organic contaminants by permanganate: Role of Pb(III)

• Simultaneous removal of organic contaminants and Pb(II) was achieved by Mn(VII). • Pb(II) enhanced Mn(VII) oxidation performance over a wide pH range. • Pb(II) did not alter the pH-rate profile for contaminants oxidation by Mn(VII). • Mn(VII) alone cannot oxidize Pb(II) effectively at pH below 5.0. • Pb(III) plays important roles on enhancing Mn(VII) decontamination process. The permanganate (Mn(VII)) oxidation has emerged as a promising technology for the remediation and treatment of the groundwater and surface water contaminated with the organic compounds. Nonetheless, only a few studies have been conducted to explore the role of the heavy metals (especially the redox-active ones) during the Mn(VII) oxidation process. In this study, taking Pb(II) as an example, its influence on the Mn(VII) decontamination performance has been extensively investigated. It was found that, with the presence of Pb(II), Mn(VII) could degrade diclofenac (DCF), 2,4-dichlorophenol, and aniline more effectively than without. For instance, over a wide pH range of 4.5–8.0, the dosing of 10 μmol/L Pb(II) accelerated the DCF removal rate from 0.006–0.25 min⁻¹ to 0.05–0.46 min⁻¹ with a promotion factor of 1.9–9.4. Although the UV-vis spectroscopic and high resolution transmission electron microscopy analyses suggested that Mn(VII) could react with Pb(II) to produce Mn(IV) and Pb(IV) at pH 6.0–8.0, further experiments revealed that Pb(II) did not exert its enhancing effect through promoting the generation of MnO₂, as the reactivity of MnO₂ was poor under the employed pH range. At pH below 5.0, it was interesting to find that, a negligible amount of MnO₂ was formed in the Mn(VII)/Pb(II) system in the absence of contaminants, while once MnO₂ was generated in the presence of contaminants, it could catalyze the Pb(II) oxidation to Pb(IV) by Mn(VII). Collectively, by highlighting the conversion process of Pb(II) to Pb(IV) by either Mn(VII) or MnO₂, the reactive Pb(III) intermediates were proposed to account for the Pb(II) enhancement effect.     

Modeling watershed-scale effectiveness of agricultural best management practices to reduce phosphorus loading

Planners advocate best management practices (BMPs) to reduce loss of sediment and nutrients in agricultural areas. However, the scientific community lacks tools that use readily available data to investigate the relationships between BMPs and their spatial locations and water quality. In rural, humid regions where runoff is associated with saturation-excess processes from variable source areas (VSAs), BMPs are potentially most effective when they are located in areas that produce the majority of the runoff. Thus, two critical elements necessary to predict the water quality impact of BMPs include correct identification of VSAs and accurate predictions of nutrient reduction due to particular BMPs. The objective of this research was to determine the effectiveness of BMPs using the Variable Source Loading Function (VSLF) model, which captures the spatial and temporal evolutions of VSAs in the landscape. Data from a long-term monitoring campaign on a 164-ha farm in the New York City source watersheds in the Catskills Mountains of New York state were used to evaluate the effectiveness of a range of BMPs. The data spanned an 11-year period over which a suite of BMPs, including a nutrient management plan, riparian buffers, filter strips and fencing, was installed to reduce phosphorus (P) loading. Despite its simplicity, VSLF predicted the spatial distribution of runoff producing areas well. Dissolved P reductions were simulated well by using calibrated reduction factors for various BMPs in the VSLF model. Total P losses decreased only after cattle crossings were installed in the creek. The results demonstrated that BMPs, when sited with respect to VSAs, reduce P loss from agricultural watersheds, providing useful information for targeted water quality management.     

MODELING PREVENTION ALTERNATWES FOR NONPOINT SOURCE POLLUTION AT A WELLFIELD IN FLORIDA1

ABSTRACT: Agricultural and urban activities in the West Wellfield Interim Protection Area (WWIPA), located in West Dade County in South Florida, have the potential to impact both the environmentally sensitive Everglades and the Biscayne Aquifer. The Hydrological Simulation Program-FORTRAN (HSPF) is used to simulate surface runoff, ground water recharge, and transport of sediments, nutrients, and pesticides in the WWIPA, as a basis to quantify impacts and evaluate alternatives. Presented are four model test runs that consider current conditions, the effect of future urbanization of the agricultural land, as well as two preventive actions to minimize pollution levels. Preventive actions include application of minimum required rates of fertilizers and replacement of fertilizers by sewage sludge. Model results show that under current practices, sediments, nutrients, and pesticides are present in surface runoff and nutrients enter the ground water, and that both urbanization and preventive actions result in pollutant reductions.     

Mutatox test: a new test for monitoring environmental genotoxic agents

In this study, Yamaska River water and Milli-Q water and organically extracted sediment extracts were used to evaluate the sensitivity of a new genotoxicity screening test, the Mutatox test. Also in this study, the samples were tested for acute and chronic toxicity using the following screening test procedures: Microtox, Daphnia magna, Ceriodaphnia reticulata and ATP-TOX Systems. The Mutatox test is based on the use of a dark mutant strain of Photobacterium phosphoreum and is sensitive to chemicals which are (1) DNA damaging agents (2) DNA intercalating agents, (3) DNA synthesis inhibitors and (4) direct mutagens. In this study, the Mutatox test was found to be a simple-to-perform sensitive procedure which added greater scope to the battery of tests approach. Preliminary indications are that this procedure may prove to be one of the more responsive and valuable tests in the 'battery of tests' approach to environmental screening.     

The use of marine sponge, Haliclona tenuiramosa as bioindicator to monitor heavy metal pollution in the coasts of Gulf of Mannar, India

The results of the present research study indicate that the heavy metal accumulation in the marine sponges provide evidence as an excellent bioindicators for monitoring heavy metal pollution between near and offshore environments of Mandapam coast of "Gulf of Mannar (GoM), India". The heavy metal concentrations in sea water and accumulation in the tissues of Haliclona tenuiramosa were analyzed by ICP-MS (inductively coupled plasma-mass spectrometry). The concentrations of metals in the coastal waters of nearshore (< 0.5 km from shore) were always higher than those in the offshore waters (2-5 km away from shore). Likewise, sponges living in the nearshore accumulated greater concentrations of heavy metals (As, Cd, Co, Cu, Fe, Mn and Ni) ranging from 2 to 17 times higher concentration than the sponges located away from the shore. A positive correlation between concentration levels in water and bioaccumulation in tissues was observed. The bioaccumulation of heavy metals in sponge tissue were in order of Fe > Mn > Ni > Cu > As > Co > Cd in both the near and offshore stations. The present results justified that a more comprehensive monitoring of presence of heavy metals in H. tenuiramosa of surrounding GoM, is necessary to help a better mitigation of the problem.     

Assessment of Groundwater Quality in a Structurally Deformed Granitic Terrain in Hyderabad, India

Geochemical study of groundwater from a structurally deformed granitic terrain near Hyderabad (India) was carried out to understand and evaluate the hydrogeochemical processes and quality of groundwater. Several trace elements (Fe, Mn, Be, Al, V, Cr, Co, Ni, Cu, Zn, As, Sr, Mo, Cd, Sb, Ba, Pb, U) along with major ions and minor elements were precisely estimated in shallow and drilled wells to know the suitability of water for drinking and irrigation purposes. Analytical data shows that pH and major ion chemistry in dug wells and bore wells do not vary significantly, while some trace elements (Fe, Mn, Al, Be, Co, Pb, U and Zn) vary in dug wells and bore wells, which can be attributed to differential mineral weathering and dissolution/precipitation reactions along fractures/joints. Although the water is not potable, it was found to be suitable for irrigation with little danger in the development of harmful level of exchangeable sodium. It is inferred that the chemical composition of the groundwater in this region is likely to have its origin from silicate weathering reactions and dissolution/precipitation processes supported by rainfall and groundwater flow.     

Sub-lethal effect of chlorpyrifos on protein metabolism of the food fish Clarias batrachus and monitoring of recovery

The effect of sub-lethal concentrations of chlorpyrifos on protein metabolism in physiological important tissues, namely gills, kidney, liver, and muscle of the freshwater fish, Clarias batrachus, was studied. Fish were exposed to 1/20th and 1/10th of 96?h LC₅₀ concentrations for 7, 14, 21, and 28 days. After 28 days of exposure, fish were released into fresh water and kept in the same for 21 days in order to study the recovery. Fish were sacrificed at the stipulated periods and gills, kidney, liver, and muscle tissues were used for the estimation of total protein, amino acids, ammonia, urea, glutamine, protease, transaminases, and phosphatases. Total protein, amino acid, and ammonia contents were decreased in all tissues for 28 days and recovery was observed during the recovery period. Urea and glutamine levels were elevated, except in kidneys, and recovered at the end of the recovery period. The activities of protease, alanine, and aspartate aminotransferases, and acid and alkaline phosphatases were elevated in the tissues for 28 days exposure at both concentrations. Recovery of these enzymes activities was noticed during depuration.