Open Access Minireview Article

Hydrocarbon Spill Site Characterization by Electrical Resistivity Tomography and Ground Penetrating Radar Methods - a Review

Oki Austin Oyinkuro, Kigighe Alvan Wariebi

Asian Journal of Environment & Ecology, Page 1-9
DOI: 10.9734/AJEE/2017/36742

Assessment of the source and geometry of contaminated soils by hydrocarbon spills is the first step towards designing an effective remediation programme. Electrical Resistivity Tomorgraphy and Ground Penetrating Radar are shown in this review to easily delineate spills under certain conditions. On a 2D-geoelctric profile of the subsurface, recent hydrocarbons spills are reflected as highly resistive anomalous zones, as biodegradation occurs spills become more conductive and may be masked by conductive soil. On a radargram fresh hydrocarbon spills are observed in zones of saturation where resistive fresh hydrocarbon spills displaces conductive water in pore spaces creating anomalous zones. Accurate interpretation of geoelectric profiles and radargrams in the Niger Delta requires knowledge of the lithology of the site of contamination which could easily be obtained by shallow drilling or pitting.

 

Open Access Original Research Article

Rubber Effluent Bio-Analyses and Its Impacts on the Microbial Community Structure of the Soil in Calabar, Nigeria

A. A. Brooks, M. L. Iyakndue, A. A. Unimke, B. E. Agbo

Asian Journal of Environment & Ecology, Page 1-9
DOI: 10.9734/AJEE/2017/35292

The study was carried out by artificially polluting an agricultural soil in Calabar with varying concentrations (0 ml, 250 ml, 500 ml, 1000 ml and 2000 ml) of rubber effluent, in which 0 ml served as control, with the aim of assessing their effect on soil microflora and fertility. The polluted soil was analysed in terms of the following parameters; microbial population, soil pH organic matter, total nitrogen, available phosphorus, electrical conductivity, calcium, magnesium, potassium, sodium, effective cation exchange capacity, exchangeable acidity and  base saturation. In the polluted soils, the total heterotrophic bacteria, total heterotrophic fungi and total heterotrophic actinomycetes increased significantly (p<.05) with a decrease in the concentration of pollutants. The total heterotrophic bacteria and total heterotrophic actinomycetes showed significant reduction with an increase in the length of pollution while total heterotrophic fungi did not show difference (p>.05) over the duration of pollution. Microbial species isolated from the polluted soil were Pseudomonas sp., Bacillus sp., Staphylococcus sp., Micrococcus sp. Flavobacterium sp., Mucor spp., Fusarium spp., Penicillum spp., Aspergillus spp., Rhizopus spp., and Streptomyces spp. In the polluted soil, pH, organic matter, total nitrogen, potassium, available phosphorus, magnesium and sodium, showed significant differences (p<.05) in their values with the control, while calcium, electrical conductivity, base saturation, effective cation exchange capacity, and exchangeable acidity did not show significant difference (p>.05) with that of the control. The results of this study revealed that light application of rubber effluent could enhance microbial proliferation and thus, increases soil fertility, while a heavy application inhibits the same.

 

Open Access Original Research Article

Extrapolation of Total Species Richness from Incomplete Inventories: Application to the Gastropod Fauna Associated to Coral Reefs in ‘Mannar Gulf Biosphere Reserve’, India

Jean Béguinot

Asian Journal of Environment & Ecology, Page 1-14
DOI: 10.9734/AJEE/2017/36831

Tropical coral reefs are known to harbor considerable biodiversity, especially among invertebrates. Gastropod fauna, as an important component of this biodiversity, yet remains poorly surveyed across most tropical reefs. Moreover, the few published inventories are generally far from being exhaustive, as is almost inevitable in practice with species-rich faunas. Hence the necessity of implementing a numerical extrapolation of species accumulation, providing both (i) estimates of the total species richness of the partially sampled sites and (ii) a way to predict the additional sampling effort needed to achieve a given additional gain in sampling completeness. Such numerical extrapolations were applied here to three partial inventories of Gastropod fauna associated to coral reefs in ‘Mannar Gulf Biosphere Reserve’. To ensure the maximal possible accuracy for extrapolations, a newly derived procedure was implemented, designed to select the least-biased among nonparametric estimators of the number of still unrecorded species. The total species richness of Gastropods at each site was estimated between 49 and 53 species according to sites. Accordingly, the completeness of the reported inventories was estimated between 71% and 78%. This, in turn, calls for further effective sampling but, also, immediately raises the question of how far to extend the extra effort with, in return, a reasonable expected benefit, in terms of the ratio between the expected number of newly recorded species and the corresponding additional sampling effort required. The least-biased extrapolation of species accumulation curves proves a convenient tool for rationally addressing this important question.

 

Open Access Original Research Article

Analysis of the Protective Measures for Workers of Tea Industry in Pakistan

Munazah Tayyab, Sana Rafiq, Sana Saeed, Maham Rafiq, Hamnah Tayyab

Asian Journal of Environment & Ecology, Page 1-5
DOI: 10.9734/AJEE/2017/36418

Tea is used almost all over the world and is brewed from the tea plant Camellia sinensis. Manufacturing of tea involves several labor intensive processes. The main risks posed are from unguarded machinery, chemical, and biological agents as well as unfavorable working conditions like high temperatures. This research study is an attempt to examine the preventive and protective measures relating to health and safety of the workers adopted in Tea industry in Pakistan.

Objectives of Study: To assess the preventive measures adopted for the workers and to make recommendations for their better occupational safety.

Materials and Methods: It was a cross-sectional descriptive study.

Results: Our results show that the mean age of workers was 31.22 ± 8.55 SD years and all of them were literate. Stress at work was noted in 11 (17.2%) workers. Among all respondents, 37 (57.8%) were using face masks and gloves while 25 (39.1%) were using only face masks. Only one person was using ear plugs.

Conclusion and Recommendations: Generally, the workers were not taking adequate measures to prevent themselves from occupational hazards. Hence, there is an urgent need to look into the matters by the management to improve the working conditions.

 

Open Access Original Research Article

Highly Efficient Treatment of Shrimp Farm Wastewater by Using the Horizontal Subsurface Flow (HSSF) Constructed Wetlands with Phragmites australis Plant

Tuan Dinh Phan, Nga Thi Dinh

Asian Journal of Environment & Ecology, Page 1-9
DOI: 10.9734/AJEE/2017/37021

Aims: This study aimed to investigate the treatment of synthetic wastewater (low salinity) followed by actual shrimp farm wastewater (high salinity) and laboratory scale of constructed wetlands (CWs).

Study Design: A horizontal subsurface flow (HSSF) constructed wetlands, which filled by layers of sand and soil, Phragmites australis was grown as wetland vegetation for the model. The dimensions of model is 1.2 m length x 0.4 m width x 0.35 m height, that devised into three zones: inlet zone and outlet zone are 0.15m filled by soil (∅= 10 – 20 mm); the treatment zone is filled by 0.25 m of soils (∅= 5 – 10 mm) at the bottom and 0.1 m of sand at the top.

Place and Duration of Study: Environmental laboratory, Department of Environment, Hochiminh City University of Natural Resources and Environment, from January 2015 to November 2015.

Methodology: The investigation was carried out in two phases: Phase 1 was run by synthetic wastewater at two levels of loading rate; the purpose of this phase is to check the performance of wetland model at low total dissolved solids (TDS) concentration.  Phase 2 was run by actual shrimp farm wastewater at low loading rate, this phase aimed to investigate the effect of high TDS concentration on the performance of constructed wetland system treating actual shrimp farm wastewater. Samples of influent and effluent were taken and analyzed such parameters of COD, TN, TP, NH4+-N, TDS by following the procedure of APHA to determine the performance of model.

Results: As a result, the average removal efficiency of COD, TN, and TP in constructed wetland model was 92.7; 95.9; and 92.77%, respectively during the phase 1. The removal efficiency of phase 2 for COD, TN, and TP was 89.39; 94.61, and 89.36%, respectively.

Conclusion: The model performed stably for treatment of both types of wastewater. The constructed wetlands model could achieve better removal efficiency in synthetic wastewater than that of shrimp farm wastewater.