Neelam Patel

Comparative performance evaluation of multi-metal resistant fungal strains for simultaneous removal of multiple hazardous metals

In the present study, five fungal strains viz., Aspergillus terreus AML02, Paecilomyces fumosoroseus 4099, Beauveria bassiana 4580, Aspergillus terreus PD-17, Aspergillus fumigatus PD-18, were screened for simultaneous multimetal removal. Highest metal tolerance index for each individual metal viz., Cd, Cr, Cu, Ni, Pb and Zn (500mg/L) was recorded for A. fumigatus for the metals (Cd, 0.72; Cu, 0.72; Pb, 1.02; Zn, 0.94) followed by B. bassiana for the metals (Cd, 0.56; Cu, 0.14; Ni, 0.29; Zn, 0.85). Next, the strains were exposed to multiple metal mixture (Cd, Cr, Cu, Ni, Pb and Zn) of various concentrations (6, 12, 18, 30mg/L). Compared to other strains, B. bassiana and A. fumigatus had higher cube root growth (k) constants indicating their better adaptability to multi metal stress. After 72h, multimetal accumulation potential of B. bassiana (26.94±0.07mg/L) and A. fumigatus (27.59±0.09mg/L) were higher than the other strains at initial multimetal concentration of 30mg/L. However, considering the post treatment concentrations of individual metals in multimetal mixture (at all the tested concentrations), A. fumigatus demonstrated exceptional performance and could bring down the concentrations of Cd, Cu, Ni, Pb and Zn below the threshold level for irrigation prescribed by Food and Agriculture Organization (FAO).

Hydrochemical evaluation and identification of geochemical processes in the shallow and deep wells in the Ramganga Sub-Basin, India

Groundwater samples were collected from 44 wells in the Ramganga Sub-Basin (RSB), India, and analysed for major ions, nutrients and trace metals. The primary goal of this study is to evaluate the hydrochemistry and to identify the geochemical processes that govern the water chemistry in the shallow and deep tube wells in the study area using geochemical methods. The knowledge of changes in hydrochemistry of the aquifers is important for both groundwater recharge and use in the region. This study found that there are substantial differences of water chemistry between shallow and deep wells. In the shallow wells, the average concentrations of total dissolved solid (TDS), Na, K, Ca, Mg, HCO3, Cl, SO4, NO3, PO4, F, Cu, Mn, Fe and Cr are twofold higher than the deep wells. The concentrations of dissolved silica in the groundwater do not vary with the depth, which implies that the variation in the water chemistry is not due to mineral dissolution alone. Major ion ratios and saturation indices suggest that the water chemistry is predominantly controlled by dissolution of carbonate minerals, silicate weathering and ion exchange reactions. Thermodynamic evaluation (ion activity ratios and stability filed diagrams) indicates that the kaolinite and gibbsite controlled the water chemistry in the both shallow and deep wells. In addition, the groundwater chemistry in the shallow wells is affected by the vertical infiltration of contaminated water from surface contamination sources and nitrification process. In the deep wells, absence of NO3 and low concentrations of Cl, SO4, PO4 and F imply the role of regional flow and denitrification in the groundwater. Results concluded that proper management plan is necessary to protect the shallow aquifer in the RSB since shallow aquifer pumping is less expensive than the deeper one.

Low-Cost Remediation and On-Farm Management Approaches for Safe Use of Wastewater in Agriculture

As freshwater sources become scarcer, wastewater use has become an inevitable and attractive option for conserving and expanding available water supplies worldwide. In low-income countries where urban agriculture provides livelihood opportunities and food security, irrigation is the most prominent and the most rapidly expanding use of wastewater. Even though the opportunities like reliable resource for supporting livelihoods and improving living standards for the urban poor are coupled with wastewater irrigation, still some risks cannot be neglected. Wastewater is a serious source of contamination for natural resources and disproportionally affects farmers and consumers due to microbial and chemical health risks. By adopting strategic risk assessment and management, framework allows reducing risks associated with wastewater irrigation. A combination of management and treatment measures which are low cost, low tech, and eco-friendly along with strategically focused policies and action plans needs to be formulated for safe and sustainable use of wastewater.

Performance evaluation of gypsum block wireless sensor network system for real time irrigation scheduling

Abstract Majority of farmers in India are irrigating their crops without using any irrigation scheduling criteria. Consequently, the application of excess irrigation water causes water logging, wastage of precious water resources, plant diseases, soil salinity as well as the lack of water results into crop water stress. In the present research work an automated Wireless Gypsum Block Sensor Network System (WSN) was developed to automate irrigation scheduling. The developed gypsum blocks sensors were interlinked with Global System for Mobile (GSM) Module with a microcontroller unit. The sensor performed well in the range of 10–19% volumetric moisture content. These sensors were reliable in the range of 30–90 kPa. The sensors highly correlated with coefficient of determination R 2 = 0.93 with slope 0.13 and small relative root mean square error (RRMSE) for given soil moisture potential at depth of 30–45 cm. The microcontroller starts the pump when soil moisture content reaches below the field capacity (FC) and stops when field reaches at FC of a given threshold rage 15–18. The field information is received by the user through mobile via transmitters and receiver using text messages. The system saves the water an average up to 7%.