Uso de resíduos industriais na remediação de solo contaminado com cádmio e zinco

This study aimed to evaluate the use of two types of industrial waste to reduce availability of zinc and cadmium in contaminated soil. The experiment was conducted in a greenhouse at the Universidade Federal Rural do Rio de Janeiro during 225 days, using a substrate contaminated with zinc and cadmium, collected from the yard of the Itaguaí Port Mining Industry, and near the site of disposal of hazardous waste from two industries, Cia Mercantil and Industrial Inga in Itaguaí. The substrate was treated with two inerting agents: an industrial residue with characteristic alkaline (Slag of Melt Shop) in two doses, 4% and 6%, and a high content of iron oxide as adsorbent (lamination of scale) in a single dose of 1%. After planting the seedlings of Eucalyptus urophylla, substrate was collected from each experimental unit to determine the bioavailable and unavailable fractions (extracted with MgCl2). The substrate, untreated, had a high content of cadmium and zinc in the bioavailable fraction. The treatments caused a reduction in the availability of these elements in the soil, as evidenced in the differential absorption by plants. Due to the increased availability of cadmium and zinc in the soil without the addition of inerting agents, plants did not survive the high levels of these elements, and died 30 days after implantation of the experiment. The dry matter yield was positively influenced by the application of inerting agents, showing better response at higher slag. The highest dose also gave the lowest concentrations of elements in plants without causing nutrient deficiency of zinc and cadmium, maintaining levels that are not toxic to the species of eucalyptus. Although showing lower concentrations of cadmium at 6% Melt Shop Slag, this dose resulted in greater extraction of this element by plants.Este trabalho teve como objetivo avaliar a utilização de dois resíduos industriais na redução de disponibilidade de zinco e cádmio em solo contaminado. O experimento foi conduzido em casa de vegetação na Universidade Federal Rural do Rio de Janeiro por 225 dias, utilizando-se um substrato contaminado com zinco e cádmio, coletado no pátio de minério do Porto de Itaguaí, e próximo ao local de disposição de resíduo perigoso da Cia Mercantil e Industrial Ingá em Itaguaí, RJ. O substrato foi tratado com dois agentes inertizantes, assim descritos: um resíduo industrial com característica alcalina (Escória de Aciaria) em duas doses 4 e 6%, e outro com alto teor de óxido de ferro como adsorvente (Carepa de Laminação), em dose única de 1%. Após o plantio das mudas de Eucalyptus urophylla, foram feitas coletas do substrato em cada unidade experimental para determinação das frações biodisponíveis (extraído com MgCl2) e a não disponível. O substrato não tratado apresentava alto teor de cádmio e zinco na fração biodisponível. Os tratamentos causaram uma redução na disponibilidade desses elementos no solo, evidenciado na absorção diferenciada pelas plantas. Por causa da maior disponibilidade do cádmio e zinco no solo sem adição dos inertizantes, as plantas não resistiram aos altos teores desses elementos e morreram 30 dias após a implantação do experimento. A produção de massa seca foi influenciada positivamente pela aplicação dos agentes inertizantes, apresentando melhor resposta na maior dose de escória de aciaria. A maior dose também propiciou as menores concentrações dos elementos nas plantas, sem provocar deficiência do micronutriente zinco e mantendo o cádmio a níveis não tóxicos para as espécies de eucalipto. Apesar de apresentar menores concentrações de cádmio na dose de 6% de Escória de Aciaria,essa dose resultou na maior extração desse elemento pelas plantas

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Agroecological management in production of radish fertilized with cow urine

Many consumers have been looking for increasingly safe foods, without agrochemicals, as those produced in organic systems. An alternative to this is the use of techniques that minimize the use of agrochemical inputs. Thus, this study aimed to evaluate the effect of cow urine application on the performance of radish crops. The experiment was carried out in Tangará da Serra, Mato Grosso, Brazil. The experimental design was a randomized block with five treatments and four replications. The treatments employed were: Organomineral leaf fertilizer (Platon-25®) and four doses of cow urine (0 mL; 35 mL; 70 mL and 105 mL). The variables evaluated were: tuberous root diameter, tuberous root length, shoot fresh mass, root fresh mass, tuberous root weight, root length. Application of cow urine, regardless of dose, influenced significantly radish development. At the 70 mL dose of cow urine, the plants showed the same development as those that received the application of organomineral fertilizer. Cow urine provided better radish performance when compared to organomineral fertilizer for most of the variables analyzed, showing that for the conditions of the study, the 105 mL dose of cow urine can be used as a foliar biofertilizer in the radish crop.Muitos consumidores têm buscado alimentos mais seguros, sem agroquímicos, como aqueles produzidos em sistemas orgânicos, uma alternativa para isso é a utilização de técnicas que minimizem o uso de insumos agroquímicos. Dessa forma, objetivou-se com este trabalho avaliar o efeito da aplicação da urina de vaca sobre o desempenho da cultura do rabanete. O experimento foi realizado no município de Tangará da Serra, Mato Grosso, Brasil. O delineamento experimental utilizado foi em blocos casualizados, com cinco tratamentos e quatro repetições. Os tratamentos empregados foram: fertilizante foliar organomineral (Platon-25®) e quatro doses de urina de vaca (0 mL; 35 mL; 70 mL e 105 mL). Foram avaliadas as variáveis: diâmetro da raiz tuberosa, comprimento da raiz tuberosa, massa fresca da parte aérea, massa fresca das raízes, peso da raiz tuberosa, comprimento das raíz. Verificou-se que a aplicação da urina de vaca, independentemente da dose, influenciou significativamente o desenvolvimento do rabanete. Na dose de 70 mL de urina de vaca as plantas apresentaram desenvolvimento igual as que receberam a aplicação do fertilizante organomineral. A urina de vaca proporcionou melhor desempenho do rabanete quando comparada ao fertilizante organomineral para a maioria das variáveis analisadas, mostrando que, para as condições do estudo, a dose de 105 mL de urina de vaca pode ser utilizada como biofertilizante foliar na cultura do rabanete

Absorção de bário por plantas de arroz (Oryza sativa L.) e mobilidade em solo tratado com baritina sob diferentes condições de potencial redox

Two parallel tests were carried out to evaluate barium solubility in soils treated with barite under reducing conditions: one in leaching columns and another with potted plants cultivated with rice. Soils were treated with three doses of barite and kept at two humidity levels. The reduction (-200 mV) condition promoted an increase in barium in the geochemical fraction of higher liability, higher concentrations of barium in the leached extracts, and higher absorption by rice plants. As a result of increased uptake and accumulation of barium, the plants showed stunted growt

Mobilidade de bário em solo tratado com sulfato de bário sob condição de oxidação e redução

In order to evaluate possible solubility of BaSO4 in soils under reducing conditions, column leaching assay was settled down, where the soil received three doses of BaSO4 (100, 300 and 3000 mg kg-1) at two humidities. After reaching an Eh of -200 mV rainfall of 200 mm per day-1 was simulated. The condition of reduction led to the increased levels of barium in the fractions of higher lability and the highest levels of barium in the leachate extract, which were above the potability standards. Only 0.05% of barium in the column that received the highest dose was removed by leaching

Toxicity of Drilling Waste from Oil Wells on Oligochaeta

<div><p>ABSTRACT The most abundant and critical elements in residues from well drilling and prospecting are barium and sodium. Ecotoxicological tests have been used to evaluate the toxicity caused by toxic substances present in the soil. The objective of the present study was to verify the effect of the application of drilling residue from oil wells on Oligochaeta activity. After incubation of the soil with residue doses – BaSO4 and NaCl – three ecotoxicological tests were performed in which the species Eisenia andrei was used as a bioindicator. The avoidance behavior test showed that there was a negative effect of the application of the residue at a dose of 234 t ha-1 on Oligochaeta activity. However, the application of BaSO4 alone did not show damage to the earthworms, unlike what was observed for NaCl application. These results indicate that sodium was the element that most restricted the activity of these organisms.</p></div

EDTA-induced phytoextraction of lead and barium by brachiaria (B. decumbens cv. Basilisk) in soil contaminated by oil exploration drilling waste

The phytoextraction of heavy metals using chelating agents has been widely studied for the remediation of contaminated soils. To evaluate the efficiency of EDTA-induced phytoextraction of Ba and Pb using Brachiaria decumbens for the remediation of soil contaminated by oil well drilling and exploration waste, an experiment was conducted by applying a single dose (6 mmol EDTA kg-1 soil) and split doses of EDTA (three applications of 2 mmol EDTA kg-1 soil). The samples were subjected to sequential extractions using the method proposed by Ure et al. (1993) as modified by Rauret et al. (1999).The application of EDTA did not influence the distribution of Ba in various chemical fractions of the soil. The dry matter production did not differ significantly between the treatments and the control, thereby demonstrating the tolerance of plants to the experimental conditions. The absorption of Pb by plants was influenced by the application of EDTA. The application of a single dose of EDTA influenced the absorption of Pb and its translocation to the aerial plant parts. The application of split doses favoured higher accumulation of Pb in roots. Because of its tolerance to heavy metals and EDTA, B. decumbens has the potential to be used in phytostabilisation

Reducing conditions on barium absorption in rice plants cultured in BaSO4-enriched soil doi: 10.4025/actasciagron.v36i1.17539

To evaluate the possible solubilization of barium sulfate in soils under reducing conditions and its effects on barium bioavailability, an Oryza sativa pot trial was established. Increasing barium doses and two redox potential conditions were evaluated. The geochemical fractionation data demonstrated that reducing conditions led to an increase in the levels of more labile forms of barium and a reduction in more stable forms. Furthermore, higher doses of barium were found to have a negative impact on grain production. The highest levels of barium accumulation in the leaves, roots, and grains were observed with the highest barium dose under reducing conditions. These results demonstrate that reducing conditions increased barium bioavailability and absorption by rice plants.