M. Vikram Reddy

Risk Assessment of Heavy Metals Contamination in Paddy Soil, Plants, and Grains (Oryza sativa L.) at the East Coast of India

Heavy metals known to be accumulated in plants adversely affect human health. This study aims to assess the effects of agrochemicals especially chemical fertilizers applied in paddy fields, which release potential toxic heavy metals into soil. Those heavy metals get accumulated in different parts of paddy plant (Oryza sativa L.) including the grains. Concentrations of nonessential toxic heavy metals (Cd, Cr, and Pb) and the micronutrients (Cu, Mn, and Zn) were measured in the paddy field soil and plant parts. Mn and Cd are found to be accumulated more in shoot than in root. The metal transfer factors from soil to rice plant were significant for Pb, Cd, Cu, Cr, Mn, and Zn. The ranking order of bioaccumulation factor (BAF) for heavy metals was Zn > Mn > Cd > Cu > Cr > Pb indicating that the accumulation of micronutrients was more than that of nonessential toxic heavy metals. The concentrations of heavy metals were found to be higher in paddy field soils than that of the nearby control soil but below permissible limits. The higher Health Index (HI) values of rice consuming adults (1.561) and children (1.360) suggest their adverse health effects in the near future.

Nutrient Status of Vermicompost of Urban Green Waste Processed by Three Earthworm Species—Eisenia fetida, Eudrilus eugeniae, and Perionyx excavatus

Major nutrient status of vermicompost of vegetable market waste (MW) and floral waste (FW) processed by three species of earthworms namely, Eudrilus eugeniae, Eisenia fetida, and Perionyx excavatus and its simple compost were assessed across different periods in relation to their respective initiative substrates. Their physical parameters—temperature, moisture, pH, and electrical conductivity—were also recorded. The nutrients—nitrogen, phosphorus, potassium, calcium, and magnesium—increased in the vermicompost and compost while the organic carbon, C/N and C/P ratios decreased as the composting process progressed from 0 to 15, 30, 45, and 60 days. The nutrient statuses of vermicomposts of all earthworm species produced from both the wastes were more than that of the compost and that of their respective substrates. Moreover, the vermicompost produced by E. eugeniae possessed higher nutrient contents than that of E. fetida, P. excavatus, and compost. The MW showed higher nutrient contents than the FW. Thus, vermicomposting is the paramount approach of nutrient recovery of urban green waste.

Impact of pharmaceutical industry treated effluents on the water quality of river Uppanar, South east coast of India: A case study

The water quality of a river that received pharmaceutical industrial effluents is evaluated through the analysis of two indices to describe the level of pollution of the river, in this paper. The indices have been computed from December 2009 to June 2011 at four sampling stations—outlet, outfall, upstream, and downstream in the Uppanar River located at Cuddalore (South east coast of India). The results were compared with the guidelines of Bureau of Indian standards for drinking water specifications (BIS 10500).The study also identifies the pollutants of pharmaceutical industrial effluents before and after treatment that affects the river water quality. Data on spatial and temporal changes in dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, pH, temperature, color, electrical conductance, total dissolved solids, total suspended solids, calcium, magnesium, hardness, sodium, and chloride were collected. The water quality indices used, Bascarón (1979) adapted Water Quality Index (WQIBA) and the Canadian Council of Ministers of the Environment-Water Quality Index 1.0 (CCME WQI), which is a well-accepted and universally applicable computer model for evaluating the water quality index. Both the indices presented similar trends, and were considered adequate for evaluating the impacts of industrial effluent on the river water bodies.

Heavy metals remediation from urban wastes using three species of earthworm (Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus)

Remediation of Cadmium (Cd), Lead (Pb), Zinc (Zn), Copper (Cu) and Manganese (Mn) by the three earthworm species - Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus from three different urban wastes (Municipal Solid Waste (MSW), Market Waste (MW) and Flower Waste (FW)) through the vermicomposting process carried out for sixty days was investigated. The metals concentrations increased gradually from the initial stage till end (P Zn > Pb > Cu > Mn) implied that Cd accumulation in earthworm tissue was more than that of substrate whereas the reverse was true for other metals.

Assessment of seasonal effects of municipal sewage pollution on the water quality of an urban canal--a case study of the Buckingham canal at Kalpakkam (India): NO3, PO4, SO4, BOD, COD and DO.

The seasonal effects of untreated and treated municipal sewage on the nutrients—nitrate (NO3), phosphate (PO4), sulphate (SO4), and the biochemical oxygen demand (BOD), chemical oxygen demand (COD) and dissolved oxygen (DO) of the receiving urban canal, the Buckingham canal at Kalpakkam (Tamil Nadu, India) was monitored monthly during pre- monsoon—2005 to post-monsoon—2006. The NO3, PO4 and SO4 contents were higher in the downstream than that of the upstream of the outfall points of treated as well as untreated sewage, of the canal. The NO3 and PO4 contents were higher during summer than that of monsoon; however the SO4 was higher during winter and lower during summer in the canal water. The BOD and COD were lower and DO was higher at the upstream than that of downstream of the canal. The concentrations of BOD and COD were higher during summer season, which decreased during monsoon season, while the DO decreased during the summer season and increased in monsoon season in the canal water. Cluster analysis applied to the six sampling points of the canal, has grouped them based on the water quality similarities.

Remediation of heavy metals from urban waste by vermicomposting using earthworms: Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus

This study revealed that three earthworm species, viz., Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus , through vermicomposting remediated heavy metals – Pb, Zn, Cd, Cu and Mn from the urban waste – organic fraction of Municipal Solid Waste [M(O)SW], vegetable Market Waste (MW) and Floral Waste (FW). The concentrations of Zn, Cd and Cu were 36.1, 50.9 and 70.2% higher in M(O)SW compared with that of MW, while the concentrations of Pb and Mn were 96.5% and 80.1% higher in MW than that of M(O)SW, respectively. Of the vermicomposts and the composts of the wastes, FW and its vermicompost possessed lower concentrations of the Cd, Pb, Zn, Cu and Mn by 72.2, 55.7, 73.6, 78.2 and 48.2% and 58.0, 77.4, 64.1, 63.0 and 71.2% compared with that of M(O)SW and MW, respectively. The concentrations of these metals were significantly lowered in the vermicompost produced by the earthworm species compared to that of the respective substrates. Their concentrations showed significant decrease across different time intervals during vermicomposting process. The removal efficiency of the heavy metals was more in the vermicompost produced by E. eugeniae than that of E. fetida and P. excavatus , and the compost ( P < 0.05).

Accumulation and mobility of heavy metals in fenugreek (Trigonella foenum-graceum L.) and tomato (Lycopersicum esculentum Mill.) grown in the field amended with urban wastes, and their composts and vermicomposts

Accumulation of cadmium (Cd), lead (Pb), zinc (Zn), copper (Cu) and manganese (Mn) in roots, stems and leaves of fenugreek and tomato grown on lateritic soil amended with municipal solid waste, market and floral waste, and their composts and vermicomposts prepared using three earthworm species, were assessed. The heavy metal accumulation in the plant parts showed significant correlations with that of their respective inputs (p root > leaf in case of Cd; root > stem > leaf in case of Zn, Pb and Cu; and leaf > stem > root in case of Mn in both the plants. The Bioaccumulation Coefficient was less than a unity for the metals in tomato and fenugreek. However, the Bio-Transfer Coefficient was more than a unity in Cd and Mn while it was reverse for Pb, Zn and Cu for both the plants.

Municipal solid waste – waste to energy conversion in India: an overview

Municipal solid waste (MSW) is generated in enormous quantities, in India, causing environmental problems. It is collected primarily by sweeping in India and dumped on the outskirts of urban areas, which pollute the environment. Such MSWs also release methane and carbon dioxide, which are important greenhouse gases. MSW comprises biodegradable material. The MSW disposal methods in India mainly include land filling, separating waste and composting, biomethanation, incineration, and conversion to refuse derived fuel (RDF). MSW can be converted to non-conventional energy (WtE). Otherwise, the MSW disposal in India open dumping facilitates breeding of ensuing serious environmental health problems. The WtE conversion is going to become important in thickly populated cities. The biodegradable waste can be processed by aerobic composting including vermicomposting and by anaerobically, biomethanation. The non-biodegradable waste such as plastic can be processed for recovering energy. There are 16 such clean development mechanisms projects recovering energy from MSW in India, of which 11 are RDF-based and a few are biomethanation-based. However, landfill gas recovery projects were not successful in India. However, there are successful small projects in Tamil Nadu (India) deriving the CH4 gas from human-waste biomethanation units generating electricity lighting street lights.

Microbial characterisation of vermicompost and compost of urban waste processed by three earthworm species – Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus

Species diversity of bacteria, fungi and actinomyctes of vermicompost and compost of the organic fraction of municipal solid waste, vegetable market waste and flower waste were assessed using pour plate technique. Of the total 91 entities, 62 were bacteria and 29 were actinomycetes in MW, followed by that of MSW and FW, with 59 and 55 bacterial; 25 and 22 actinomycetes entities, respectively. The biodiversity of bacteria and actinomycetes were significantly higher in the vermicomposts produced by Eudrilus eugeniae followed by that of Eisenia fetida and Perionyx excavates and that of composts (p < 0.05). The bacterial count was found to be significantly higher in the substrates compared to the fugal count (p < 0.05). Actinomycetes not found at the beginning appeared at the end of vermicomposting and composting. Actinomycetes count was significantly more than that of fungal and of bacterial count at end of processing (p < 0.05).