• Energy Research
• 6. Clean water close

Indiscriminate and injudicious application of inorganic fertilizers and irrigation, respectively, cause declines in crop productivity as well as environmental pollution. Therefore, judicious use of organic manures and proper scheduling of irrigation are required for sustainable production of wheat crops. A two-year (2014–2015 and 2015–2016) study was conducted to determine the wheat nutrient uptake, soil moisture, and grain yield as a result of organic manures and irrigation schedule. The experiment was set up with four treatments of organic manure in four subplots with repellents and five irrigation planning treatments in the main plot. The results showed that an irrigation/water ratio of 0.9 irrigation water depth/cumulative pan evaporation (I2) increased grain yield, soil moisture content, and nutrient uptake of wheat (I3) compared to 0.6 IW/CPE during the vegetative period and 0.8 IW/CPE during the reproductive period. According to statistics, it was found that the vegetative period is maintained at 0.8 IW/CPE, and the reproductive period is maintained at 1.0 IW/CPE (I5). Applying 7.5 Mg ha−1 of farmyard manure (FYM) plus 3 Mg ha−1 of vermicompost while employing organic manure increases grain output, soil moisture content, and nutrient content and absorption compared to the control treatment. Therefore, it is concluded that irrigation either at I2 or I5 + FYM at 7.5 Mg ha−1 + vermicompost at 3 Mg ha−1 could be recommended for enhancing grain of wheat cultivation, particularly in the semiarid regions of northwestern India.

The treatment of heavy metal-contaminated water is challenging. The use of nanomaterials from many environmental wastes is promising for removing metals and contaminants from aqueous solutions. This study is novel in using nanobiochar of water hyacinth (WH) and black tea waste (TW) as a promising approach to water decontamination owing to its unique properties that play an effective role in metal adsorption. The mono- and multi-adsorption systems of cadmium (Cd), chromium (Cr), and nickel (Ni) on biochar and nanobiochar of water hyacinths (BWH and NBWH) and black tea waste (BTW and NBTW) were investigated in this study as potential low-cost and environmentally friendly absorbents for the removal of previously mentioned heavy metals (HMs) from aqueous solutions. The WH and TW were collected from the locality, prepared, and kept until used in the experiment. Nanobiochar was prepared by grinding, characterizing, and storing in airtight containers until used. A batch experiment was designed in mono- and competitive systems to study the adsorption equilibrium behavior of HMs on biochar and nanobiochars. The Freundlich and Langmuir isotherm models were fitted to the mono- and competitive-adsorption equilibrium results. The Freundlich isotherm model provided a better fit. Furthermore, it was noticed that NBWH and NBWT efficiently removed the Cd in the mono-system by ≥99.8, especially in the smaller concentration, while NBWT and BTW removed ≥99.8 and 99.7% in the competitive system, respectively. In the mono- and competitive systems, the nanobiochars of NBTW removed more than 98.8 of Cr. The sorbents were less efficient in Ni removal compared to Cd and Cr. However, their effectiveness was very high also. The results revealed that Cd was the highest metal removed by sorbents, nanobiochars were better than biochars to remove the HMs, and the results also indicated that co-occurrence of multi-metals might fully occupy the adsorption sites on biochars and nanobiochars.