Abstract Quality of groundwater is threatened due to pollution by industrial, domestic and agricultural waste. A large number of populations are residing in rural areas which are unable to afford high cost water purifiers due to their low income as well as limited awareness. However, limited availability of fresh water has become a critical issue in developing countries. Around 1.2 billion population is deprived of affordable and safe water for their domestic need. Additionally, chemical coagulants which are nowadays being used for water purification pose severe and numerous health hazards to human. Thus utilization of easily accessible natural coagulant for water purification might offer a sustainable, practical and cost effective solution to the current alarming situation in developing countries. Several experimental findings have shown strong efficiency of Moringa oleifera plant extracts obtained from different solvents in the improvement of water quality parameters including physicochemical (such as pH, hardness, turbidity, metallic impurities, total dissolved solid) and biological (E.coli count) parameter. We have also highlighted the limitations and advantages of chemical coagulation in water purification. Altogether, this review summarizes one such miracle tree which has shown significant potential as a natural coagulant and its associated underlying mechanism in water purification process. industrial waste awareness However countries 12 1 2 1. need Additionally human sustainable pH hardness turbidity impurities solid E.coli Ecoli E coli count parameter Altogether process

Cadmium, a high toxicity element, is a potential threat to plant and human health, and a dangerous pollutant in the environment. Uptake and accumulation by crops represent the main entry pathway for potentially health-threatening toxic metals into human and animal food. Crops and other plants take up Cd from the soil or water and may distribute it in their roots and shoots. Soil and/or water are usually contaminated with Cd through natural sources, industrial effluent, and anthropogenic activities. In this review, the sources of Cd contamination, evaluation of the phytotoxic effects on plants, and mode of action of Cd toxicity, were summarized. Plant defensive strategies upon excess Cd are also considered in this review. Cd-induced effects include oxidative stress, disintegration of the photosynthetic apparatus, reduction in gas exchange parameters, nutrient imbalance, and subcellular organelle degradation. In addition, Cd severely impairs biomolecules such as DNA, protein, and lipids. Although plants are sessile in nature, they are equipped with certain mechanisms to cope with unfavorable conditions. These mechanisms include synthesis of metal-chelating proteins, expression of enzymatic and non-enzymatic antioxidants, organic acids, and plant root-mycorrhiza association. The built-in system of plant tolerance to Cd can be further enhanced by the application of exogenous organic and inorganic metal sources. This review will broaden the knowledge about the Cd accumulation in plants and the responses to metal exposure, as well as our understanding of metal tolerance and overcoming this serious issue for sustainable agriculture and human health worldwide.

El Cadmio, con su alta tasa de toxicidad, constituye una amenaza potencial para la salud humana y las plantas, es un contaminante peligroso en el medio ambiente. La absorción y acumulación en los cultivos representan la principal vía de entrada de metales tóxicos en alimentos para humanos y animales, potencialmente peligrosos para la salud. Los cultivos y otras plantas absorben Cd del suelo o del agua y pueden distribuirlo en sus raíces y brotes. El suelo y/o el agua se contaminan con Cd generalmente a través de fuentes naturales, efluentes industriales y actividades antropogénicas. En esta revisión, se resumieron las fuentes de contaminación de Cd, la evaluación de los efectos fitotóxicos en las plantas y el modo de acción de la toxicidad. Además, las estrategias de las plantas para protegerse del exceso de Cd. Los efectos inducidos por Cd incluyen el estrés oxidativo, la desintegración del aparato fotosintético, la reducción de los parámetros de intercambio de gases, el desequilibrio de nutrientes y la degradación de los orgánulos subcelulares. Además, el Cd deteriora gravemente las biomoléculas como el ADN, las proteínas y los lípidos. Aunque las plantas son de naturaleza sésil, están equipadas con ciertos mecanismos para hacer frente a condiciones desfavorables. Estos mecanismos incluyen la síntesis de proteínas quelantes de metales, la expresión de de la planta y la micorriza. El sistema incorporado de tolerancia de plantas al Cd puede mejorarse aún más mediante la aplicación de fuentes orgánicas e inorgánicas de metales exógenos. Esta revisión ampliará el conocimiento sobre la acumulación de Cd en plantas y las respuestas a la exposición a metales, así como la comprensión de la tolerancia al metal y la superación de este grave problema para la agricultura sostenible y la salud humana en todo el mundo.