In the present world, climate change is a mass talked issue. Because of climate change, humans and animals are under the risk of threatening. The scientist has pointed out that main reasons for climate change are waste. Waste is generated from household chores and industries, factories etc. that are affecting the balance of the environment in many ways. This waste may be of various types such as solid, liquid, gaseous etc. Therefore, the study was taken to assess the chemical components contain in wastewater in Dinajpur Sadar, Bangladesh. This study was aimed to evaluate the chemical compositions of the generated wastewater including comparison with the groundwater. The data concerning to the rice mill waste water in Dinajpur, Bangladesh was obtained from individual field visits by interviewing with owner and worker in the rice mills. The wastewater samples were collected randomly from different rice mills. A laboratory experiment was performed to determine the chemical constituents of the wastewater sample. The wastewater contained of pH(6.11-6.18), EC(181.47-185.23 µScm-1), Na(26.19-28.89 mgl-1), Ca(45.41-51.26 mgl-1), Mg(47.12-49.8 mgl-10), K(184.7-191.3 mgl-1), TDS(45.94-47.96 mgl-1), HT(306.7-332.33 mgl-1), S(11.05-13.25 mgl-1), Cl-(522.45-526.182 mgl-1), HCO3-(5.12-6.99 mgl-1), DO(0.46-0.53 mgl-1), P(17.01-21.54 mgl-1). The obtained concentration of Ca, EC, pH, Na and HCO3- were within the reported range of groundwater in Dinajpur, Bangladesh. The concentration of Cl-, K, P, Mg and hardness in the wastewater were above the concentration of reported groundwater in Dinajpur, Bangladesh. On the other hand, the concentration of TDS in the wastewater was less than the reported concentration of groundwater in Dinajpur, Bangladesh.

La Planta de Tratamiento de Aguas Residuales de Cañaveralejo -PTAR-C de Cali- Colombia, produce alrededor de 100 t/día de biosólidos que, aunque no tienen restricción por metales pesados, son clase B por el nivel de microorganismos patógenos y parásitos. En un diseño completamente al azar, conformado por seis tratamientos con su respectivo duplicado, se evaluó la estabilización alcalina con dosis del 9% peso a peso de cal viva e hidratada, aplicada a pilas de 0.5 t de biosólidos húmedos (66.5%) y secos a temperatura ambiente (25 - 31°C) durante 72 h (humedad 50.1%). Con la estabilización alcalina el pH aumentó a valores superiores a 12 unidades durante el tiempo suficiente para garantizar la reducción de patógenos y parásitos, alcanzando un material clase A; sin embargo, el biosólido seco facilitó la formación de grumos que dificultaron las labores de homogenización del sustrato con los alcalinizantes, factor indeseable para la eficiente reducción de patógenos. | The Cañaveralejo wastewater treatment plant (PTAR-C) based in Cali-Colombia, produces almost 100 t-day-1 of biosolids. Although do not have heavy metals restrictions, it is class B for high contents of pathogens microorganisms and parasites. The alkali stabilization was done with a 9% of dose (w/w) of quicklime and hydrated lime applied to different 0.5 ton piles of wet biosolids (66.5% humidity) and dry biosolids an environmental temperature (25-31°C) for 72 hours (50.1% humidity). The experiment had a completely randomized design and it was composed by 6 treatments with their respective duplicated. With the alkali stabilization, the pH increments above 12 units during enough time to assure pathogens and parasites reduction in order to achieve a class A material level. On the other hand, the dry biosolids facilitate the conditions for lumps formation that reduce the homogenization of the substrate with the alkali material, which it is and undesirable factor for pathogen reduction.

La Planta de Tratamiento de Aguas Residuales de Cañaveralejo -PTAR-C de Cali- Colombia, produce alrededor de 100 t/día de biosólidos que, aunque no tienen restricción por metales pesados, son clase B por el nivel de microorganismos patógenos y parásitos. En un diseño completamente al azar, conformado por seis tratamientos con su respectivo duplicado, se evaluó la estabilización alcalina con dosis del 9% peso a peso de cal viva e hidratada, aplicada a pilas de 0.5 t de biosólidos húmedos (66.5%) y secos a temperatura ambiente (25 - 31°C) durante 72 h (humedad 50.1%). Con la estabilización alcalina el pH aumentó a valores superiores a 12 unidades durante el tiempo suficiente para garantizar la reducción de patógenos y parásitos, alcanzando un material clase A; sin embargo, el biosólido seco facilitó la formación de grumos que dificultaron las labores de homogenización del sustrato con los alcalinizantes, factor indeseable para la eficiente reducción de patógenos.