पुढील उतारा वाचून त्यावर आधारित प्रश्नांची उत्तरे द्या :
सांडपाणी व्यवस्थापन आणि भूमी शुद्धीकरण (Sewage Land Treatment)
जेव्हा सांडपाणी जमिनीवर पडते तेव्हा मातीत असणारे जीवाणू त्यावर आक्रमण करतात आणि सांडपाण्यातील घटकांचे वनस्पतींना उपयुक्त अन्नात रूपांतर करतात. वनस्पती नंतर ते आपल्या मुळांद्वारे शोषून घेतात. सांडपाण्यात असणारे सेंद्रिय पदार्थ एरोबिक आणि नॉन-एरोबिक (ऑक्सिजनजीवी व विना-ऑक्सिजनजीवी) जीवाणूंद्वारे अपघटित होतात, परंतु जमिनीमार्फत होणारी एरोबिक अपघटन क्रिया अधिक फायदेशीर असते. एरोबिक अपघटनासाठी आवश्यक असणारा ऑक्सिजन हा जमिनीच्या विविध थरांमध्ये उपलब्ध असतो. अपघटनामुळे तयार होणारा कार्बन डायऑक्साइड हा जमिनीकडून वातावरणास दिला जातो व त्या बदल्यात वातावरणातील ऑक्सिजन शोषून घेतला जातो. ही ऑक्सिजन आणि कार्बन डायऑक्साइडची देवाणघेवाण वाऱ्याचे वहन, तापमानातील बदल, बदलणारा दाब, मातीचे गाळप इत्यादी प्रक्रियांमुळे होते. जेव्हा सांडपाणी जमिनीवर टाकले जाते तेव्हा ऑक्सिडेशन रासायनिक प्रक्रिया सुरू होते त्यामध्ये सांडपाण्यातील सेंद्रिय घटकांचे जमिनीतील जीवाणू ऑक्सिडेशन करतात. गाळणाचे तत्त्व हे भौतिक प्रक्रियेचे जमिनीमार्फत होणाऱ्या सांडपाण्याच्या शुद्धीकरण प्रक्रियेचे मुख्य तत्त्व आहे. जेव्हा सांडपाणी जमिनीच्या विविध थरांतून संक्रमित होते, तेव्हा त्याचे विविध कण जमिनीच्या थरांमधील सूक्ष्म छिद्रांमध्ये अडकवून ठेवले जातात. नंतर पुरेशा हवेच्या सानिध्यात एरोबिक जीवाणू त्यांचे ऑक्सिडेशन करतात. ही भौतिक प्रक्रिया मुख्यत्वे जमिनीच्या प्रकारावर अवलंबून असते. सरंध्र मोकळ्या, कणीदार, मृदू जमिनीमध्ये ही गाळण प्रक्रिया अधिक उत्तम आणि समाधानकारक असते. जड आणि चिकट माती ही गाळण प्रक्रियेसाठी फारशी उपयुक्त नसते तर खडकाळ जमीन ही गाळण प्रक्रियेसाठी पूर्णतः निरुपयोगी असते.
सांडपाण्यामध्ये पाण्याचे प्रमाण खूप जास्त असते जे सिंचन प्रक्रियेसाठी वापरले जाऊ शकते. सांडपाण्यामध्ये नायट्रोजन, पोटॅशियम, फॉस्फेट्स आणि सेंद्रिय आम्ले इत्यादी असतात म्हणून त्यांचे पोषणमूल्य जास्त असते, या घटकांमुळेच सांडपाण्याचा वापर वनस्पती स्वतःच्या वाढीसाठी त्वरित करू शकतात. याचाच अर्थ सांडपाण्यामुळे जमिनीचे पोषणमूल्य वाढते व तिचा पोत सुधारतो. सदर जमिनीवर कोणते पीक घ्यायचे हे प्रामुख्याने त्यामध्ये असणाऱ्या सांडपाण्याच्या प्रमाणावर आणि दर्जावर निर्धारित असते.
सांडपाण्याच्या जीवाणूंमार्फत होणाऱ्या एरोबिक अपघटनाच्या प्रक्रियेत _______.
(a) आवश्यक असलेला ऑक्सिजन हा सरळ वातावरणातून घेतला जातो.
(b) तयार झालेल्या कार्बन डायऑक्साइडची अदलाबदल वातावरणातील ऑक्सिजनबरोबर होते.
(c) मातीच्या विविध थरांत उपलब्ध असलेला कार्बन डायऑक्साइड वापरला जातो.
पर्यायी उत्तरे :
EN
Read the following passage and answer the questions:
Sewage Land Treatment & Soil Purification When sewage is dropped on land, the bacteria present in the soil attack on it and convert the content of sewage into plant food. The latter gets utilized by the roots of the plants or crops. The organic matter present in sewage undergoes decomposition by aerobic and non-aerobic bacteria, but it is profitable to provide aerobic conditions for the disposal of sewage by land treatment. The oxygen that is required for aerobic decomposition, is present in different layers of the soil. The CO2 produced as a result of decomposition is given by the soils and in turn, atmospheric oxygen is absorbed. This interchange of oxygen and carbon dioxide takes place by wind movements, difference in temperature and pressure, drainage of soils and many other processes. When sewage is applied on land, the chemical process of oxidation takes place in which organic matter of the sewage is oxidised by bacteria. Filtration is the principal physical action that is involved in the purification of sewage by land treatment. Sewage as it passes through the layers of the soils gives out suspended particles which are retained by the voids of the soil. In presence of sufficient aeration, these particles are oxidised by aerobic bacteria. This physical action mainly depends on the nature of the soil. Most suitable and satisfactory filtration takes place in porous, loamy or sandy soils. The heavy soils such as clay are not very suitable for filtration, while rocky soils are most unsuitable for filtration. The major portion present in sewage is water, and it can be used for irrigation. Sewage also contains nitrogen, potash, phosphate, organic acids etc and so it has a good fertilizer value, because these constituents present in sewage can be directly used by the plants for their growth. In this way, sewage increases the fertility of the soils and also improves the condition of the soil. The type of crop that can be grown, mainly depends on the quality of sewage and health regulations concerning the use of sewage on crops. During the aerobic decomposition of sewage by bacteria, _______ : (a) The required oxygen is directly taken from the atmosphere.
(b) The produced carbon dioxide is interchanged with atmospheric oxygen.
(c) The carbon dioxide present in different layers of soil is used. Answer Options :
Sewage Land Treatment & Soil Purification When sewage is dropped on land, the bacteria present in the soil attack on it and convert the content of sewage into plant food. The latter gets utilized by the roots of the plants or crops. The organic matter present in sewage undergoes decomposition by aerobic and non-aerobic bacteria, but it is profitable to provide aerobic conditions for the disposal of sewage by land treatment. The oxygen that is required for aerobic decomposition, is present in different layers of the soil. The CO2 produced as a result of decomposition is given by the soils and in turn, atmospheric oxygen is absorbed. This interchange of oxygen and carbon dioxide takes place by wind movements, difference in temperature and pressure, drainage of soils and many other processes. When sewage is applied on land, the chemical process of oxidation takes place in which organic matter of the sewage is oxidised by bacteria. Filtration is the principal physical action that is involved in the purification of sewage by land treatment. Sewage as it passes through the layers of the soils gives out suspended particles which are retained by the voids of the soil. In presence of sufficient aeration, these particles are oxidised by aerobic bacteria. This physical action mainly depends on the nature of the soil. Most suitable and satisfactory filtration takes place in porous, loamy or sandy soils. The heavy soils such as clay are not very suitable for filtration, while rocky soils are most unsuitable for filtration. The major portion present in sewage is water, and it can be used for irrigation. Sewage also contains nitrogen, potash, phosphate, organic acids etc and so it has a good fertilizer value, because these constituents present in sewage can be directly used by the plants for their growth. In this way, sewage increases the fertility of the soils and also improves the condition of the soil. The type of crop that can be grown, mainly depends on the quality of sewage and health regulations concerning the use of sewage on crops. During the aerobic decomposition of sewage by bacteria, _______ : (a) The required oxygen is directly taken from the atmosphere.
(b) The produced carbon dioxide is interchanged with atmospheric oxygen.
(c) The carbon dioxide present in different layers of soil is used. Answer Options :