Issue 10 (in progress)

Municipal solid waste [MSW] has gained prominence in recent years as the rate of its generation has increased significantly. The serious problem of MSW management exists in almost all regions of India. This study aims to generate energy from MSW by selecting a suitable MSWM technology with the help of MSW characterization of Haridwar city. The suitable technique chosen was anaerobic digestion (AD) by physical and chemical characterization of MSW. The organic fraction of municipal solid waste (OFMSW) of 96 sub-samples with two different inoculums i.e., livestock dung and anaerobic sludge were used for AD experiments. A total of eight batch-type laboratory-scale anaerobic reactors were used in mesophilic conditions with different subtract-inoculum ratios (1/3, 1/2, 1/1, and 2/1). The S/I ratio of 1/1 was optimum for both inoculums. In this situation, the average cumulative biogas and methane yields for livestock dung were 461 NmL/g OM and 440 NmL/g OM, respectively, compared to 628 NmL/g OM and 474 NmL/g OM for anaerobic sludge. The anaerobic sludge inoculum was found to be better than livestock dung, with cumulative biogas production and methane yield being 3.5% and 4.2% higher, respectively.

Clean water and its requirement are one of the emerging needs in recent days. Water pollution creates more amount of toxic nature to the clean water and it increases the accumulation of poisonous contaminants in the water sources. Heavy metal ions are the type of toxic pollutant released from textile industrial effluent, changes the natural color of clean water. In this study, Adsorption behavior with activated biochar Gracilaria Edulis as adsorbent was investigated under batch mode for removing detecting elevated levels of metallic cations in aqueous solutions. The biochar adsorbent was prepared with chemical synthesis process and their surface area analyzed using N2 adsorption process. The presence of targeted heavy metal ions was confirmed using SEM and EDX analysis. The maximum adsorption efficiency of 99.9% of Cr, 97.37% of Ni and 92.73% of Zn heavy metal ions was achieved using the biochar adsorbent. The endothermic reaction in between adsorbent and adsorbent was confirmed using the thermodynamic studies and maximum amount of spent adsorbent was recovered by using desorption process by adding strong hydrochloric acid with 0.3 N.

In this study, an attempt is made to understand the effectiveness on initial treatment of coconut shell on the strength of concrete. The coconut shell materials obtained from the agricultural wastes are used as a replacement for coarse aggregate in conventional concrete. From the particle size distribution graph, the CS aggregates follow a similar trend of smooth grain distribution when compared to conventional aggregates. Coconut shell aggregates were treated using different method with the solutions of sodium silicate, calcium hydroxide, polyvinyl alcohol and with heat. Treated coconut shells were tested for water absorption and their resistance to crushing and impact. Water absorption of PVA treated aggregates was reduced from 17.7% to 4.0% portraying the effectiveness of pre-treatment procedure. Compared to the untreated coconut shell aggregates, the impact and crushing values of heat treated ones reduced by 75.8% and 87.8% respectively. Coconut shell concrete specimens were tested for 28-day compressive strength, split tensile strength and flexural strength. The results of treated coconut shell concrete were compared with untreated coconut shell concrete. Compressive and split tensile strengths of CS concrete also increased with heat treatment whereas the flexural strength improved due to the calcium hydroxide treated aggregates. Micro-structural characterisation using Scanning Electron Microscope (SEM) analysis showed the presence of strong interface between the aggregate particles and concrete.

Microplastics were discovered in soil samples taken from fields in Tamil Nadu, India's Ponneri, Redhills, and Thirumazhisai where the fields had been amended with compost made from biowaste. The soil sample taken from agricultural field in Ponneri had the highest microplastic level, which was determined to be 3.28±0.8 g/kg. The duration of compost addition has a big impact on how microplastics are distributed. When compared to Redhills (5 years’ compost amendment) and Thirumazhisai (3 years’ compost amendment), the agricultural fields of Ponneri had greater microplastic concentration after 8 years of biowaste compost amendment. The Scanning Electron Microscope (SEM) analysis revealed the presence of multiple forms of microplastics in the study area, including fragments, fibres, and pellets. SEM research confirmed that the surface topography of microplastics exhibited cavities and cracks as a result of weathering activity. Fourier transform infrared (FTIR) spectroscopy analysis confirmed that polypropylene type microplastic was present in the study area. Additionally, the presence of microplastics in the biowaste compost had no impact on the bacterial population or microbial activity in the soil.