Fabrication of efficient and low-cost adsorbents through enzyme induced carbonate precipitation (EICP) of sand embedded with binding agents for sulfathiazole (STZ) removal is reported for the first time. Sand enriched with biochar (300 °C, 500 °C, and 700 °C), xanthan gum, guar gum, bentonite, or sodium alginate (1% w/w ratios) was cemented via EICP technique. Enrichment with binding agents decreased the unconfined compressive strength, improved the porosity, and induced functional groups. Biochar enrichment reduced the pH, and increased the calcite contents and electrical conductivity. Fixed-bed column adsorption trials revealed that biochars enrichment resulted in the highest STZ removal (64.7–87.9%) from water at initial STZ concentration of 50 mg L⁻¹, than the adsorbents enriched with other binding agents. Yoon–Nelson and Thomas kinetic models were fitted well to the adsorption data (R² = 0.91–0.98). The adsorbents embedded with 700 °C biochar (BC7) exhibited the highest Yoon–Nelson rate constants (0.087 L min⁻¹), 50% breakthrough time (58.056 min), and Thomas model-predicted maximum adsorption capacity (4.925 mg g⁻¹). Overall, BC7 removed 168% higher STZ from water than pristine cemented sand. Post-adsorption XRD and FTIR analyses suggested the binding of STZ onto the adsorbents. π–π electron-donor-acceptor interactions, aided-by electrostatic interactions and H-bonding were the main STZ adsorption mechanisms.

Vertical translocation/leaching of sulfamethoxazole (SMZ) through manure-amended sandy loam soil and significance of biochar application on SMZ retention were investigated in this study. Soil was filled in columns and amended with manure spiked with 13.75 mg kg⁻¹ (S1), 27.5 mg kg⁻¹ (S2), and 55 mg kg⁻¹ (S3) of SMZ. Jujube (Ziziphus jujube L.) wood waste was transformed into biochar and mixed with S3 at 0.5% (S3-B1), 1.0% (S3-B2), and 2.0% (S3-B3) ratio. Cumulative SMZ leaching was lowest at pH 3.0, which increased by 16% and 34% at pH 5.0 and 7.0, respectively. A quicker release and translocation of SMZ from manure occurred during the initial 40 h, which gradually reduced over time. Intraparticle diffusion and Elovich kinetic models were the best fitted to leaching data. S3 exhibited the highest release and vertical translocation of SMZ, followed by S2, and S1; however, SMZ leaching was reduced by more than twofold in S3-B3. At pH 3.0, 2.0% biochar resulted in 99% reduction in SMZ leaching within 72 h, while 1.0% and 0.5% biochar applications reduced SMZ leaching to 99% within 120 and 144 h, respectively, in S3. The higher SMZ retention onto biochar could be due to electrostatic interactions, H-bonding, and π-π electron donor acceptor interactions.

Application of manure and compost can result in the accumulation of veterinary antibiotics in soil, subsequently posing ecological risks. The occurrence and potential ecological risk assessment of nine antibiotics (4 tetracyclines, 3 sulfonamides, and 2 macrolides) residues in soil, manure, and compost samples collected from Al-Kharj, Saudi Arabia are reported in this study. A total of 36 samples (20 soil, 8 manure, and 8 compost) were collected and their physiochemical characteristics were analyzed. Large variabilities were observed in organic matter, pH, electrical conductivity, and nutrient status. In the soil samples obtained, three textural groups were identified: sandy loam, loamy sand, and loam. Overall, the mean concentrations of all detected antibiotics measured were lower (<50 μg kg⁻¹) in all matrices (soil, manure, and compost). However, the mean concentrations of tetracycline (TC), doxycycline (DC), oxytetracycline (OT), and sulfamethoxazole (SMZ) were 97.96, 183.29, 101.24, and 69.58 μg kg⁻¹, respectively, in manure samples, and 49.59, 93.26, 74.21, and 18.32 μg kg⁻¹, respectively, in compost samples. The concentrations of antibiotics were highest in manure samples, then compost, and finally soil. The calculated risk quotient (RQ) values for the majority of the studied antibiotics were <0.1, indicating no to low adverse ecological effects. However, the higher RQ values for OT and DC suggested possible adverse ecological effects of these compounds in soil.

Millions of human pathogenic viral particles are shed from infected individuals and introduce into wastewater, subsequently causing waterborne diseases worldwide. These viruses can be transmitted from wastewater to human beings via direct contact and/or ingestion/inhalation of aerosols. Even the advanced wastewater treatment technologies are unable to remove pathogenic viruses from wastewater completely, posing a serious health risk. Recently, coronavirus disease 2019 (COVID-19) has been urged globally due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which has resulted in >4.1 million deaths until July 2021. A rapid human-to-human transmission, uncertainties in effective vaccines, non-specific medical treatments, and unclear symptoms compelled the world into complete lockdown, social distancing, air-travel suspension, and closure of educational institutions, subsequently damaging the global economy and trade. Although, few medical treatments, rapid detection tools, and vaccines have been developed so far to curb the spread of COVID-19; however, several uncertainties exist in their applicability. Further, the acceptance of vaccines among communities is lower owing to the fear of side effects such as blood-clotting and heart inflammation. SARS-CoV-2, an etiologic agent of COVID-19, has frequently been detected in wastewater, depicting a potential transmission risk to healthy individuals. Contrarily, the occurrence of SARS-CoV-2 in wastewater can be used as an early outbreak detection tool via water-based epidemiology. Therefore, the spread of SARS-CoV-2 through fecal-oral pathway can be reduced and any possible outbreak can be evaded by proper wastewater surveillance. In this review, wastewater recycling complications, potential health risks of COVID-19 emergence, and current epidemiological measures to control COVID-19 spread have been discussed. Moreover, the viability of SARS-CoV-2 in various environments and survival in wastewater has been reviewed. Additionally, the necessary actions (vaccination, face mask, social distancing, and hand sanitization) to limit the transmission of SARS-CoV-2 have been recommended. Therefore, wastewater surveillance can serve as a feasible, efficient, and reliable epidemiological measure to lessen the spread of COVID-19.

The development of a simple method to synthesize highly efficient and stable magnetic microsphere beads for sulfathiazole (STZ) removal from contaminated aqueous media was demonstrated in this study. Conocarpus (Conocarpus erectus L.) tree waste (CW) derived biochar (BC) was modified to fabricate chitosan-BC (CBC) and magnetic CBC (CBC-Fe) microsphere beads. Proximate, chemical, and structural properties of the produced adsorbents were investigated. Kinetics, equilibrium, and pH adsorption batch trials were conducted to evaluate the effectiveness of the synthesized adsorbents for STZ removal. All adsorbents exhibited the highest STZ adsorption at pH 5.0. STZ adsorption kinetics data was best emulated using pseudo-second order and Elovich models. The equilibrium adsorption data was best emulated using Langmuir, Freundlich, Redlich–Peterson, and Temkin models. CBC-Fe demonstrated the highest Elovich, pseudo-second order, and power function rate constants, as well as the highest apparent diffusion rate constant. Additionally, Langmuir isotherm predicted maximum adsorption capacity was the highest for CBC-Fe (98.67 mg g⁻¹), followed by CBC (56.54 mg g⁻¹) and BC (48.63 mg g⁻¹). CBC-Fe and CBC removed 74.5%–108.8% and 16.2%–25.6% more STZ, respectively, than that of pristine BC. π-π electron-donor–acceptor interactions and Lewis acid-base reactions were the main mechanisms for STZ removal; however, intraparticle diffusion and H-bonding further contributed in the adsorption process. The higher efficiency of CBC-Fe for STZ adsorption could be due to its magnetic properties as well as stronger and conducting microsphere beads, which degraded the STZ molecules through generation of HO^• radicals.

Elevated levels of doxycycline (DC) have been detected in the environment due to its extensive utilization as a veterinary antibiotic. Sorption–desorption behavior of DC in soil affects its transport, transformation, and availability in the environment. Thus, sorption–desorption behavior of DC was explored in three soils (S1, S2, and S3) after manure application with and without mesquite wood-waste-derived biochar (BC) pyrolyzed at 600 °C. Sorption batch trials demonstrated the highest DC sorption in soil S1 as compared to S2 and S3, either alone or in combination with manure or manure + BC. Chemical sorption and pore diffusion were involved in DC sorption, as indicated by the kinetic models. Soil S1 with manure + BC exhibited the highest Langmuir model predicted sorption capacity (18.930 mg g⁻¹) compared with the other two soils. DC sorption capacity of soils was increased by 5.0–6.5-fold with the addition of manure, and 10–13-fold with BC application in a soil–manure system. In desorption trials, manure application resulted in 67%, 40%, and 41% increment in DC desorption in soil S1, S2, and S3, respectively, compared to the respective soils without manure application. In contrast, BC application reduced DC desorption by 73%, 66%, and 65%, in S1, S2, and S3, respectively, compared to the soils without any amendment. The highest DC sorption after BC application could be due to H bonding, π–π EDA interactions, and diffusion into the pores of BC. Hence, mesquite wood-waste-derived BC can effectively be used to enhance DC retention in contaminated soil to ensure a sustainable ecosystem.

Purpose

The Kingdom of Saudi Arabia is continuously in search of environment-friendly farming practices since mass-scale agriculture was initiated. It is imperative to gauge to the level of awareness of the farmers on the agricultural practices causing environmental issue in order to devise new agricultural extension programs. This research aims to identify the attitudes of farmers towards agriculture and environment in Al-Ghat area of Saudi Arabia.

Methodology

A simple random sample of 110 farms truly representing the farming community was drawn to meet the objectives of the study. Data were collected by using the pre-tested questionnaire during the face-to-face interviews. In order to understand the message of study, data were analyzed for percentages, arithmetic average and standard deviation in addition to the simple Pearson correlation coefficient.

Results

The results showed that the high proportion (87.3%) of farmers was interested in continuing to work farm and 77.3% of farmers did not consider adopting agriculture their main occupation. The findings of the survey reveal that some 55.5% of the respondent farmers were aware of the agricultural practices and their relation to the environment. Some 57.3% of the surveyed farmers are aware of potential benefits of enhanced utilization of agricultural organic wastes. However, main profession, farm employment (as the independent variables) showed a significant positive correlation with the attitudes of farmers towards their working in agriculture (as a dependent variable). Also a significant negative relationship between the educational levels and the attitudes of the farmers towards working in agriculture was noticed. The study also indicated a significant correlation between education and the degree of awareness of agricultural practices related to the environment and maximizing the optimum utilization of agricultural waste i.e. organic residues.

Conclusions

The study suggested the need for new awareness and orientation programs to educate farmers and extension workers, highlighting the environment- friendly agricultural practices.

Recommendation: There is need to offer incentives and facilities to keep the farmers stay in the farming business. Extension staff must keep educating them on beneficial features of organic farm waste and crop residues as organic fertilizers.

Fifty

HEstimation of Heterosis and Combining Ability Effects on Grain Yield and Some Agronomic Traits of Sorghum under Three NPK Fertilizers Levels
M.A. Sayed# and M.T. Said
Agronomy Department, Faculty of Agriculture, Assiut University, Assiut, Egypt.
ETEROSIS and combining ability for grain yield and some …….agronomic traits were studied among thirty F1 grain sorghum crosses and their elven parents under three NPK levels during 2014 and 2015 seasons. Significant differences among genotypes were found for all studied traits, indicating wide genetic diversity. The interaction of genotypes with each of years and NPK levels were significant in most studied traits. The analysis of variance for combining ability revealed that the mean square due to entries, parents, parents vs. crosses, crosses, lines, testers, lines × testers turned up significant for all studied characters and suggesting that the experimental materials possessed considerable variability that both general and specific combining ability were involved in the genetic expression of these characters. The female line ICSB610 showed significant and negative general combining ability (GCA) effects for days to 50% heading and panicle length and positive for grain yield and plant height. It may be used to develop high yielding, early flowering, and tall hybrids with short panicles. For specific combining ability (SCA), effects, the crosses ICSA613 × ICSR89028 and ICSA20 × ICSR53 gave positive and highly significant SCA effects which indicated that these crosses can be considered desirable combiners. These crosses had also high grain yield per se and one of the parents with highest GCA effects. The observations on portioning of combining ability variance into additive and dominance variances indicated the role of both additive and dominance gene action. The magnitude of non-additive variance was higher than the additive variance by many folds for all studied traits.