Synergistic optimization of electrocoagulation process parameters using response surface methodology for treatment of hazardous waste landfill leachate.

Leachate treatment is an essential and integral part of solid waste management system, and its efficient treatment becomes more crucial when the leachate is produced from industrial or hazardous waste landfills (HWLs), as it is multi-fold more toxic than the leachate produced from municipal solid waste landfills (MSWLs). Electrocoagulation has appeared to be a promising technology for treating complex wastewater including MSWL leachate, but specific treatability studies dedicated to HWL leachate are rarely available, and thus pose a demand for fundamental and advance research in this area to bridge the existing gap. The current study delves into systematic design of experiments to check the treatability of HWL leachate through electrocoagulation, considering reduction (maximum) in chemical oxygen demand (COD) as a response variable. Response Surface Methodology (RSM) was used for design of experiments and process optimization and three-dimensional surface response was also created to understand the relationship among process parameters and response variables. After extensive experimental trials and data analysis, it was observed that electrocoagulation can be used as a potential treatment technology for leachate with Galvanized Iron (GI) as preferable electrode material and it resulted up to 90% reduction in COD under optimized condition. Significant reduction in other parameters was also observed with a removal efficiency of 58.1%, 63.6%, 42.4%, 52.5%, 54.7% and 84% for cadmium, zinc, phenolic compounds, lead, TOC, and colour, respectively. The results showed that Electrocoagulation can be used as a replacement of currently practised energy extensive treatment technologies like multiple effect evaporators, which are used by landfill operators for managing their HWL leachate. The methodology and results from this research may be utilized by the researchers and operators of HWL landfills to decide the treatment trail for HWL leachate.

E-waste management and its effects on the environment and human health.

Challenges in managing electronic waste (E-waste) arise from a lack of technical skills, poor infrastructure, inadequate financial support, and inactive community engagement. This study provides a systematic review of efforts to overcome these challenges in the context of inappropriate recycling protocols of E-waste and their toxic effects on human health and the environment. An inventory of end-of-life electronic products, which can be established through the creation of an environment friendly regulatory regime for recycling, is essential for the proper control of E-waste. An approach has been articulated to help implement effective management of E-waste in both developed and developing countries. Enforcement of systematic management measures for E-waste in developing countries coupled with best practices is expected to minimize adverse impacts while helping maintain a sustainable and resilient environment.

GABAergic effect of valeric acid from Valeriana wallichii in amelioration of ICV STZ induced dementia in rats

ABSTRACT Valeriana wallichii DC., Caprifoliaceae, is used to have anti-ulcer, anti-spasmodic, anti-epileptic, memory enhancer, anti-anxiety, anti-rheumatic, sedative, anti-asthmatic and diuretic activities. V. wallichii is reported to contain valpotriates, valeric acid, valerenic acid, valechlorine, valerianine, resins and alkaloids. Valeric acid, found in V. wallichii appears similar in structure to the neurotransmitter GABA. Valeric acid also acts as an NMDA-receptor antagonist. The aim of present study was to investigate the neuroprotective effect of V. wallichii containing valeric acid and its possible mechanism of action in amelioration of intracerebroventricular streptozotocin induced neurodegeneration in Wistar rats. The rhizomes of V. wallichii were powdered coarsely and extracted by percolation method using dichloromethane. Wistar rats (220–250 g) of either sex were divided into 5 groups, comprising 6 animals each. Valeric acid was isolated from plant extract and characterized using FT-IR. Picrotoxin (2 mg/kg) was used as GABA-A antagonist. Intracerebroventricular streptozotocin administration caused significant (p < 0.05) increase in escape latency, retention transfer latency on morris water maze on 17th, 18th, 19th and 20th day and elevated plus maze on 19th and 20th day respectively, as compared to normal untreated rats. Treatment with V. wallichii extract 100 and 200 mg/kg and valeric acid 20 and 40 mg/kg significantly decreased the escape latency and retention transfer latency, as compared to intracerebroventricular-streptozotocin group. Plant extract and valeric acid also decreased the level of lipid peroxidation and restored glutathione level in rat brains. Administration of picrotoxin significantly reversed the effects produced by plant extract and valeric acid in intracerebroventricular-streptozotocin treated rats. The findings may conclude that valeric acid present in V. wallichii has significant GABAergic effect in amelioration of experimental dementia.