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In this review article, discuss the many ways utilized by the dairy sector to treat pollutants, emphasizing their influence on the quality and efficiency with which contamination is removed. It focuses on biotechnology possibilities for valorizing dairy waste in particular. The findings revealed that dairy waste may be treated using physicochemical, biological, and biotechnological techniques. Notably, this article highlighted the possibility of dairy waste being used as a feedstock not only for the generation of biogas, bioethanol, biohydrogen, microbial fuel cells, lactic acid, and fumaric acid via microbial technology but also for the production of biooil and biochar by pyrolysis. In addition, this article critically evaluates the many treatment techniques available for recovering energy and materials from dairy waste, their combinations, and implementation prospects. Valorization of dairy waste streams presents an opportunity to extend the dairy industry's presence in the fermented functional beverage sector.

Abstract Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy demand of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (Note: 35 Rs approximates to $US 1.)

Human milk is considered as a complete food since it constitutes all the major essential nutrients, minerals, and vitamins to sustain the life. Human milk is responsible for the evolution of an efficient immune system and organ development as well as acts as a protective barrier against inflammation and infection. In addition, it is known to be a good source for polyunsaturated fatty acids (PUFAs) which are indispensable for brain and retinal development as well as growth of a child. The amount of PUFAs in the human milk varies depending on several factors such as lactation stage, maternal diet, external environment, and maternal health. In this work, we demonstrate the optimization of a detection method for estimating PUFAs in the human milk using a UV–Visible spectrophotometer. For this purpose, fatty acids were extracted from the human milk using three different types of methods, namely Hara and Radin method (HR), Bligh and Dyer (BD) method, modified Bligh and Dyer (MBD) method. Further, we compared the efficacy of all three methods on the basis of the yield of fatty acids obtained and the solvents used for extraction. The outcomes indicated that modified BD method could be the best choice amongst the three methods tested for fatty acid extraction from the human milk. In addition, the study exploited docosahexaenoic acid (DHA) in its pure form as a standard candidate of PUFA and revealed its absorption spectrum using a spectrophotometer. A sharp absorbance peak at a wavelength of 205 nm was observed to be characteristic of DHA. Also, the height of the absorbance peak was found to be varying depending upon the concentration of DHA; revealing the linear relationship between absorbance and concentration. Therefore, we characterized the absorbance plot of fatty acids extracted from the various samples of human milk at 205 nm and noticed a trend similar and well correlated with that of DHA. Thus, we anticipate that the optimized method could be utilized as a preliminary routine test to examine the PUFA content in the human milk. Keywords: Docosahexaenoic acid (DHA), Fatty acids, Human milk, Health, UV–Visible spectrophotometer

Abstract Developing efficient and cost effective solar dryer with thermal energy storage system for continuous drying of agricultural food products at steady state and moderate temperature (40–75 °C) has become potentially a viable substitute for fossil fuel in much of the developing world. Solar energy storage can reduce the time between energy supply and energy demand, thereby playing a vital role in energy conservation. The rural and urban populations, depend mainly, on non-commercial fuels to meet their energy needs. Solar drying is one possible solution but its acceptance has been limited partially due to some barriers. A great deal of experimental work over the last few decades has already demonstrated that agricultural products can be satisfactorily dehydrated using solar energy. Various designs of small-scale solar dryers having thermal energy storage have been developed in the recent past, mainly for drying agricultural food products. Therefore, in this review paper, an attempt has been taken to summarize the past and current research in the field of thermal energy storage technology in materials as sensible and latent heat in solar dryers for drying of agricultural food products. With the storage unit, agricultural food materials can be dried at late evening, while late evening drying was not possible with a normal solar dryer. So that, solar dryer with storage unit is very beneficial for the humans and as well as for the energy conservation.

Abstract As atmospheric CO2 is rising alarmingly, focused research on microalgal based bio-mitigation of CO2 has become relevant. With the aim of single-objective maximization, response surface methodology (RSM) study was employed through central composite design (CCD) for the phototropic cultivation of Nannochloropsis sp. using Flue gas and synthetic fertilizer (NPK-10:26:26). Influence of crucial external factors such as light, salinity, carbon content and nutrients were investigated along with their interactions on three objectives such as Biomass, Lipid, and carbon bio-fixation rate. Using fertilizer assisted RSM optimized media, an enhancement of 43, 31, and 79% was observed in three responses over standard f/2 medium. Variation in carbon content (32%) and C/N ratio (100%) was observed, that validated diversion of metabolism under stress. The multi-objective optimization was carried out by genetic algorithm. A carbon supply strategy was employed that enhances biomass growth. Carbon sequestration was calculated first time precisely. Light intensity was concluded as a dominant external inducer to carbon-sequestration and lipid accumulation. Carbon sequestration rate was revealed to enhance in conditions that favor both good growths and induce stress. Single and multi-objective optimization data in this study can help in commercial decision making required in large scale-cultivations for biotechnological gains.

Abstract Algae are fast-growing, microscopic, and eukaryotic organisms that can perform photosynthesis, and simultaneously fix atmospheric CO2. Algal cells contain high quantity of biofuel precursors such as starch and lipid granules. In the past decades, microalgal biomass has emerged as a potential feedstock for bioenergy generation. In the current scenario, it is being extensively explored to produce liquid (bioethanol, biodiesel) and gaseous (biomethane, biohydrogen) fuels. Algal technology has four crucial aspects including strain selection and its cultivation, harvesting techniques, conversion routes, and pretreatment of biomass. The quality and quantity of biomass, available media source, cultivation system as well as environmental conditions collectively help in the selection of the specific algal strain. Despite several in-depth attempts, there are various hurdles and limitations to make algal biofuel technically and economically viable. To meet the operational and economic feasibility, a collective approach is desirable. The present state-of-the-art review deals with all four crucial aspects of algal technology. The manuscript especially covers the significant methods of harvesting, energy conversion, and pretreatment. Moreover, it also revels the advantage of biological agent mediated harvesting, energy conversion and the pretreatment of algal biomass for sustainable biofuel recovery. The prime objective of this review is to give an insight into the aspects of algal technology to promote collective research in the area of algal biofuel.

An analytical study of a controlled-environment agricultural system for the hot and dry climate of Delhi has been carried out in terms of design parameters to provide favourable environmental conditions for the optimal growth of plants. The effect of water flow over the greenhouse has also been incorporated in the thermal analysis. It is observed, analytically and numerically, that the flowrate of the water should be large to achieve minimum thermal flux into the controlled-environment agricultural system.

Enormous quantity of water is used for coal beneficiation and accordingly huge amount of effluents are being generated. In this study an attempt was made to evaluate the potential of this effluent water for irrigation. Water samples were collected from three different points (a) feeding point, (b) thickening point, and (c) outlet point of coal washery, and from Damodar River for monitoring the water quality. The samples were analyzed for various parameters and compared with prescribed standard, which revealed that the total suspended solids of thickening point and Damodar River were higher. A pot experiment with maize was conducted to study the suitability of this coal washery water for irrigation. Pots were irrigated with water from the three points of washery and Damodar River in two concentrations (100% and 50% dilution with distilled water); pure distilled water was used for control. There was 100% germination in all the treatments. The plant growth, chlorophyll content and soil quality parameters were significantly better in washery and Damodar River water treated pots. The Damodar River water and washery water from feeding and outlet point could be successfully used for irrigation. In general mixing with good quality water has shown better results.

Abstract Biomass, which is available in plenty, plays an important role in meeting the energy needs of the rural areas in most of the developing countries. Different crop residues were screened for optimum utilization. Cauliflower residues can be used as an unconventional fodder because of their nutritive value, while bhindi and tomato residues can be used for biogas production and mustard residues for charcoal production.