Resumo O experimento foi realizado em manga cv. Dusehri para investigar o efeito dos fertilizantes N, P e K no crescimento vegetativo, reprodutivo, produtividade e de qualidade do fruto. Foram utilizadas oito combinações diferentes de fertilizantes: T1 (controle), T2 (N), T3 (P), T4 (K), T5 (NP), T6 (NK), T7 (PK) e T8 (NPK). Cada tratamento de N (1.000 g), P (750 g) e K (750 g) foi aplicado duas vezes durante a estação de crescimento em fevereiro e agosto. Todos os tratamentos influenciaram significativamente o crescimento vegetativo, floração, frutificação, produtividade e outros atributos físico-químicos da manga em relação ao controle. Menos efeito foi observado com a aplicação individual de fertilizante, enquanto os tratamentos combinados aumentaram a maioria dos parâmetros investigados. Especialmente as características qualitativas mostraram diferenças não significativas entre mangueiras tratadas e não tratadas. No entanto, entre os diferentes tratamentos, T8 (NPK) apresentou significância para aspectos de frutificação, como tamanho máximo de folgas de crescimento (177,51 mm), número total de panículas/árvore (845), número total de flores/panícula (974), razão sexual (69,18%), retenção de frutos (13,85%), número total de frutos/árvore (379), produção (82 kg/árvore), peso do fruto (197,5 g) e peso da polpa (135,5 g), além de parâmetros físico-químicos, como TSS (24,53), vitamina C (57,63 mg/100 mL) e açúcar total (20,84%). Em geral, a aplicação combinada de NPK (T8) foi a mais eficaz no aprimoramento dos aspectos de frutificação, produtividade, características físico-químicas, além da melhoria da qualidade dos frutos das mangueiras.

Abstract The experiment was carried out on mango cv. Dusehri to investigate the effect of N, P and K fertilizers on vegetative, reproductive growth, yield and fruit quality. Eight different fertilizer combinations such as T1 (control), T2 (N), T3 (P), T4 (K), T5 (NP), T6 (NK), T7 (PK) and T8 (NPK) were used. Individual or combine fertilizer application of N (1000 g), P (750 g) and K (750 g) were applied during growing season in February and August. All the treatments significantly influenced on vegetative growth, flowering, fruiting, yield and other physiochemical attributes of mango as compared to control. Least effect was observed with individual fertilizer application while combine fertilizer treatments enhanced most of the investigated parameters. Especially, qualitative traits showed non-significant differences between treated and untreated mango trees. However, among the different treatments T8 (NPK) showed significance for fruiting aspects such as maximum size of growth flushes (177.51 mm), total number of panicles/tree (845), total number of flowers/panicle (974), sex ratio (69.18%), fruit retention (13.85%), total number of fruits/tree (379), yield (82 kg/tree), fruit weight (197.5 g), pulp weight (135.5 g) and physiochemical parameters namely TSS (24.53), Vit. C (57.63 mg/100 mL) and total sugar (20.84%). In general, combine application of NPK (T8) were the most effective in enhancing fruiting aspects, yield, physiochemical characteristics as well as improved fruit quality of mango trees.

The biosorption of lead(II) and chromium(VI) on groundnut hull was investigated. Batch biosorption experiments were conducted to find the equilibrium time and biosorption capacity. Effect of parameters like pH, temperature and initial metal concentration was studied. The maximum biosorption capacity of lead(II) and chromium(VI) was found to be 31.54 ± 0.63 and 30.21 ± 0.74 mg g-1, respectively. The optimum pH for lead(II) and chromium(VI) removal was 5 ± 0.1 and 2 ± 0.1, respectively. The temperature change, in the range of 20 - 45ºC affected the biosorption capacity. The maximum removal of lead(II) was achieved at 20 ± 2ºC, where as maximum uptake of chromium(VI) was observed at 40 ± 2ºC. The biosorption data was fitted to the Langmuir and the Freundlich isotherm models. The Langmuir model showed better representation of data, with correlation coefficient greater than 0.98. The kinetics of biosorption followed the pseudo second order kinetics model. The thermodynamics parameters were evaluated from the experimental data.

Presence of heavy metals in the aquatic systems has become a serious problem. As a result, there has been a great deal of attention given to new technologies for removal of heavy metal ions from contaminated waters. Biosorption is one such emerging technology which utilized naturally occurring waste materials to sequester heavy metals from industrial wastewater. The aim of the present study was to utilize the locally available agricultural waste materials for heavy metal removal from industrial wastewater. The wastewater containing lead and hexavalent chromium was treated with biomass prepared from ficus religiosa leaves. It was fund that a time of one hr was sufficient for sorption to attain equilibrium. The equilibrium sorption capacity after one hr was 16.95 ± 0.75 mg g-1 and 5.66 ± 0.43 mg g-1 for lead and chromium respectively. The optimum pH was 4 for lead and 1 for chromium. Temperature has strong influence on biosorption process. The removal of lead decreased with increase in temperature. On the other hand chromium removal increased with increase in temperature up to 40ºC and then started decreasing. Ion exchange was the major removal mechanism along with physical sorption and precipitation. The biosorption data was well fitted to Langmuir adsorption model. The kinetics of biosorption process was well described by the pseudo 2nd order kinetics model. It was concluded that adsorbent prepared from ficus religiosa leaves can be utilized for the treatment of heavy metals in wastewater