Assessing the arsenic-saturated biochar recycling potential of vermitechnology: Insights on nutrient recovery, metal benignity, and microbial activity

Biochar mediated pollutant removal is gaining attention because of high efficiency of the process. However, effective recycling avenues of the pollutant-saturated biochars are scarce in the knowledge base; while such materials can be a new source of long-range contamination. Therefore, potential of vermitechnology for eco-friendly recycling of pollutant-loaded biochar was assessed by using arsenic-saturated native (NBC) and exfoliated (EBC) biochars as feedstocks for the first time. Interestingly, the bioavailable arsenic fractions (water soluble and exchangeable) considerably reduced by 22–44 % with concurrent increment (~8–15 %) of the recalcitrant (residual and organic bound) fractions in the biochar-based feedstocks. Consequently, ~2–3 folds removal of the total arsenic was achieved through vermicomposting. The earthworm population growth (2.5–3 folds) was also highly satisfactory in the biochar-based feedstocks. The results clearly imply that Eisenia fetida could compensate the arsenic-induced stress to microbial population and greatly augmented microbial biomass, respiration and enzyme activity by 3–12 folds. Moreover, biochar-induced alkalinity was significantly neutralized in the vermibeds, which remarkably balanced the TOC level and nutrient (N, P, and K) availability particularly in EBC + CD vermibeds. Overall, the nutrient recovery potential and arsenic removal efficiency of vermitechnology was clearly exhibited in NBC/EBC + CD (12.5:87.5) feedstocks. Hence, it is abundantly clear that vermitechnology can be a suitable option for eco-friendly recycling of pollutant-saturated sorbing agents, like biochars

Impact of N fertilization on C balance and soil quality in maize-dhaincha cropping sequence

Excess N fertilization to achieve high crop yield is a grand old practice in developing countries. However, inorganic nutrient sources considerably replenish soil organic C (SOC). In the present study, we applied six different levels of N keeping P and K constant for maize, grown under maize (Zea mays) - dhaincha (Sesbania aculeata) cropping sequence. We recorded high crop yield, profuse root biomass and SOC stock with increasing N fertilization. Moreover, water holding capacity, microbial biomass carbon and particulate organic carbon improved significantly with increasing levels of N. Conversely, bulk density, mineral associated organic carbon and pH decreased with increasing application of inorganic N. Furthermore, a significant positive correlation was recorded between root biomass and soil organic carbon. A study of the sensitivity index showed particulate organic carbon and microbial biomass carbon to be good indicators of nutrient management practices. Dhaincha cultivation accelerated C and N mineralization in soil, which is reflected in increased biomass and crop yield. Hence, we conclude that inorganic N fertilization rate (7280 kg ha-1) in maize-dhaincha cropping sequence successfully maintains the SOC balance and optimize N stock in soil

Outbreaks and sporadic cases of japanese encephalitis in the state of Odisha, India: Outcome of 7 years of laboratory surveillance

Acute encephalitis syndrome (AES) is a major public health challenge in India. We report here the epidemiology of sporadics and outbreaks of Japanese Encephalitis (JE) in Odisha state during 2012–2018. A total of 4235 AES cases (sporadics – 3394, outbreak cases – 841) recorded including 42 outbreaks; majority (n = 18) of which were during 2016. Overall JE virus (JEV) positivity was 11.78% (outbreak cases – 24.5%, sporadic cases – 8.6%). Age ≤15 years were largely affected during outbreaks, while 16–60 years population was dominant among sporadics. The major outbreak (2016) involved 336 patients from a tribal dominated district, spread over 173 villages. JEV seropositivity was high (43.45%) with 28.57% mortality. Epidemiological linkage with pig rearing was documented through JEV neutralizing antibodies in 50% of pig serum samples. Although the postvaccination period (2017–18) showed increase in AES case reporting but low JE proportion. Ongoing surveillance and preparedness of the health system would be of importance, especially in tribal-dominated districts

Self-Aggregation of MEGA‑9 (<i>N</i>‑Nonanoyl‑<i>N</i>‑methyl‑d‑glucamine) in Aqueous Medium: Physicochemistry of Interfacial and Solution Behaviors with Special Reference to Formation Energetics and Micelle Microenvironment

Self-aggregation of MEGA-9 (<i>N</i>-nonanoyl-<i>N</i>-methyl-d-glucamine), a nonionic sugar-based surfactant, was studied with respect to the effect of salt (NaCl) and ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) on its critical micelle concentration (cmc), aggregation number, hydrodynamic dimensions, energetics of micellization, and micellar microenvironment. Fluorimetry (both steady state and time resolved) was used to understand the microenvironments under the influence of additives. NaCl was found to decrease cmc, increase aggregation number (<i>N</i>), increase micellar size, and decrease enthalpy of micelle formation; the IL effect on the parameters was mostly opposite. The microscopic properties of micelles were probed using two fluorophores: one nonpolar C-153 (2,3,5,6-1<i>H</i>,4<i>H</i>-tetrahydro-8-trifluormethylquinolizino-(9,9<i>a</i>,1-<i>gh</i>)­coumarin) and the other fairly polar ANS (8-anilinonaphthalene-1-sulfonate); they delivered information on the palisade layer and the peripheral region of the micelle interface, respectively. Energy of activation and entropy of activation of the dynamics of the probes were evaluated from their decay time, lifetime, and rotational movements in the regions of residency in the micelles. Density functional theory (DFT) calculations showed that the ternary combination MEGA-9/IL/H₂O had the maximum interaction energy compared to any of the binary combinations. Thus, the ionic liquid reduced MEGA-9 self-association to a large extent