This report deals with converting the agriculture waste (rice straw) to environmental cleaner materials (biochar) using airless pyrolysis followed by eco-friendly activation. The biochar (p-Biochar) obtained after pyrolysis step (poorly active material) was activated using wet attrition method to give m-Biochar (highly active materials). The both p-Biochar and m-Biochar were characterized in detail and utilized for MB and CV dye removal from aqueous solution. Various parameters affecting the adsorption process such as dye concentration, adsorbent dose, contact time, temperature, NaCl dose and pH were investigated. The adsorption isotherm was well fitted using Langmuir isotherm, and the maximum adsorption capacity is 90.91 and 44.64 mg/g, for MB and CV dyes, respectively. The contact time data obtained showed that the two dyes were poorly adsorbed over p-Biochar. The equilibrium was reached quickly in 15 min for MB dye and 20 min for CV dye using the m-Biochar, and removal percent was 94.45 and 92.70% for MB and CV dyes, respectively. Moreover, the kinetic isotherm presented very well fitted by pseudo-second-order model. In addition, the adsorption percent increases with further increasing the pH value. Finally, we observed that m-Biochar highly adsorbs the MB dye compared with the CV dye over all experimental conditions.

Opuntia spp. are crops well adapted to adverse environments and have great economic potential. Their constituents, including fruits, cladodes, and flowers, have a high nutritional value and are rich in value-added compounds. Cladodes have an appreciable content in dietary fiber, as well as bioactive compounds such as kaempferol, quercetin, and isorhamnetin. Fruits are a major source of bioactive compounds such as phenolic acids and vitamin C. The seeds are mainly composed of unsaturated fatty acids and vitamin E. The flowers are also rich in phenolic compounds. Therefore, in addition to their traditional uses, the different plant fractions can be processed to meet multiple applications in the food industry. Several bakery products have been developed with the incorporation of cladode flour. Pectin and mucilage obtained from cladodes can act as edible films and coatings. Fruits, fruit extracts, and fruit by-products have been mixed into food products, increasing their antioxidant capacity and extending their shelf life. Betalains, obtained from fruits, can be used as food colorants and demonstrate promising applications as a sensor in food packaging. This work reviews the most valuable components of the different fractions of this plant and emphasizes its most recent food applications, demonstrating its outstanding value.

Brewer’s spent grain represents approximately 85% of the by-products generated by the beer industry. It is acidic and rich in organic matter and nutrients. In Egypt, spent grain has no value and is available at no cost all year. Incubation and germination experiments were conducted to assess the potential of using spent grain and compost to increase soil fertility and squash (Cucurbita pepo L.) growth in a calcareous soil. Amendments were two rates of spent grain (13.5, 26.7gkg−1), two rates of compost (24.7, 49.4gkg−1), a blend of lowest rates of compost and spent grain and a control. Treatments were mixed with calcareous soil, placed in pots and incubated anaerobically under field conditions for one month. After incubation 15 squash seeds were planted in the soil pots. Highest rate of spent grain most effectively increased soil water holding capacity, organic matter, macronutrients, micronutrients, germination parameters, and reduced soil pH. Mixing compost with spent grain was more effective than high rate of compost in increasing water holding capacity, soil nutrients, and decreasing soil pH. While both treatments were equally effective in enhancing squash germination and increasing soil organic matter. Spent grain is more effective than compost in improving properties of calcareous soils, and is much less expensive

This review article discusses humic substances – specific organic compounds, which are the substantial part of the bioenergy matrix of the food chains of living creatures and the essence of the exchange interaction of those media. The dead organisms (mostly plants) are transformed into humic substances. A prerequisite for creating the monograph was a steady interest in humic substances from humus specialists (soil scientists, agricultural chemists, coal chemists, etc.) and biologists, physicians, and workers in agriculture, forestry, and communal services. At the same time, monographs are quite rare in the literature, where humic substances are described quite fully. Based on our experience in studying humic substances, we have attempted to characterize humic substances comprehensively. Collecting disparate information and analyzing it made it possible to obtain a more or less holistic view of such a unique natural object as humic substances. Much attention is paid to the colloidal properties of these specific compounds. We must not forget that humic substances are a necessary and mandatory component of all metabolic processes in the biosphere.