Waste water agriculture Threats, challenges and remedies


Raw city effluent represents the untreated sewage or waste water which normally contains plant


nutrient, toxic chemicals, organic and inorganic pollutants and pathogens. The frequency and


volume of effluents are increasing day by day due to unplanned and unchecked urbanization.


The mushroom growth of urban population and industries has absorbed the major share of fresh


water and dispose it into drains in the form of waste water. In Pakistan the bulk quantities of


effluents are mixed in nature contributed by municipal, industrial, hospital and agricultural


sectors. Composition of waste water varies depending upon the source, industries in a particular


area and living standards of inhabitants. Municipal waste effluents are constituted by the


discharge from the households, institutions and commercial buildings trash or garbage while


industrial effluents contain wastewater from industries like Tanning, Textile, Sugar, Vegetable


ghee and cooking oil, Cement, Chemical and Fertilizer industry etc. The composition of


industrial effluent contains dyes, solids, organic chemicals, heavy metals, oils, sulphates and


cyanide pollutants. Hospital effluents contain wastewater from surgical operations and


pharmaceutical disposals like diagnostic tissues, used needles and syringes, medical devices,


blood and liquid medicines while the agriculture field operation and routine operation at animal


farms are the constitute of agriculture effluent.


In Pakistan the total quantity of waste water produced 9.6 x 10 5 million gallons (4.39 x 109


m 3 /yr). The estimated volume of wastewater discharge (cusec) from different cities of Pakistan


like Lahore (3304), Faisalabad (1278), Gujranwala (312), Multan (235), Rawalpindi (171),


Sargodha (99), Sialkot (92), Gujrat (42), Shiekhupura (416), Jhang (21) and others cities


(421.60) in 2010. The Faisalabad city generates approximately 280 Million Gallons of waste


water per Day more as compared to all others cities. Annually sewage water and the total


capacity of waste water treatment plant (Chakera) contain approximately 20 Millions of Gallons


per Day. The total volume of wastewater produced by the industrial, commercial, residential


and agriculture sector is about 395, 266, 4687 and 1036 x 10 6 m 3 yr -1 respectively. Collection of

interesting reading:  Tick repellents & Remedies to stay safe against Tick bites


effluents and its safe disposal is the responsibility of the Water and Sanitation Agencies


(WASAs) in major cities and the Tehsil Municipal Administrations (TMAs) in developing cities


but they have failed in managing such a large quantity of uncontrolled effluents in many cities


of Pakistan like Faisalabad, Islamabad and Karachi where about less than 20% of its generated


sewerage is being treated. In Pakistan, water bodies and agricultural land are acting as the major


dumping sites of this hazardous waste water.


In Pakistan, agriculture is the biggest sector which greatly influences the socio-economic


conditions of rural community. Agriculture adds 20.9% to Gross domestic product (GDP) in


Pakistan. Water acts as the backbone of agriculture but uneven and industry tilted distribution of


fresh water has created acute shortage of good quality water. Beside this curse high prices of


fertilizers and unavailability of proper nutrients at proper time and at proper stage of crops are


also the limiting factors for the traditional agriculture. To combat with these problems, the


nutritional value and around the clock availability of wastewater has grabbed the attention of


the farmers, opting wastewater for agriculture purpose. From total waste water produced almost


30% is used for irrigating an area of about 32,500 hac in Pakistan.


This practice is reducing the cost of production of agricultural commodities, lessening the


fertilizer and water expenses. The most striving contaminants in waste water are heavy metals


sourced from different anthropogenic activities and having agriculture lands as their final


destination. These metals are non-biodegradable, having great persistence in soils. The major


portion of heavy metals remains phyto-available and has high risk to enter food chain via plants


grown on these contaminated agricultural lands. These heavy metals are carcinogenic and


patients in bulk have been reported in cancer hospitals due to outrageous heavy metals exposure


directly or indirectly. Moreover, stomach diseases, skin allergies, malaria, mental disorders and


kidney failure are other curses of this contamination. Soil contamination with heavy metals

interesting reading:  1LINK starts 24/7 SOC handling cyber security threats


through wastewater irrigation largely affects the biological and physical properties of soil.


Various biochemical and physiological disorders of plants are also the result heavy metals


toxicity. Disposal of untreated waste water into fresh water bodies is causing serious threat such


water borne diseases in Pakistan like diarrhea, salmonellosis, typhoid, shigellosis and gastric


ulcers. Variety of salts of nitrates and heavy metals has been reported to leach down into ground


water. Once ground water may get contaminated it is impossible to remediate it. Ground


water of the Faisalabad city is not suitable for domestic, irrigation and industrial purpose which


is creating extra pressure on utilization of fresh water. By drinking such type of contaminated


water diseases like hepatitis in Samundri, Gastroenteritis in Lahore, typhoid, kidney and


stomach problems in Faisalabad have been reported.


As water scarcity is the major issue all over the world, the survival only lies in the utilization of


fresh water wisely and in an appropriate way. Follow “more crop per drop” in all stack holder


sectors of fresh water including agriculture sector. The first step is the implementation of


existing laws and policies to giant industries to replace or make the existing treatment plants


functional. The waste water and sewerage water can be reused for agriculture sector by


remediating it using bio-sorbents, chemi-sorbents and phytoremediation. Bio-sorption is a


physiochemical method that takes place naturally in certain biomass that concentrates and binds


the solid wastes onto its cellular structure. This method makes use of peelings of vegetables,


eggshells, bones and peat etc. to act as bio-sorbents that remove the heavy metals from the


contaminated water. Scientists believe that it is an economic and environment friendly


technique to remove the heavy metals from waste water. Besides bio-sorbents, various


chemicals are being in use to treat the wastewater.


The different chemical processes such as chemical coagulation, chemical precipitation,


chemical oxidation and advanced oxidation, ion exchange and chemical neutralization and


stabilization are used to decontaminate the waste water and make it reusable. Phytoremediation

interesting reading:  1LINK starts 24/7 SOC handling cyber security threats


is the use of plants for the remediation purposes that act as the hyper accumulators such as


bamboo, kikar, shahtut/ mulberry, popular, neem and dharaik. In Pakistan, about 26% of


national vegetable production is irrigated with waste water. Instead of growing vegetables with


sewerage water cultivation of trees that accumulate the heavy metals will act as constrain for the


entry of heavy metals into food chain. These trees could be use for the fuel and energy


production purposes instead of food production. There is increasing understanding of “treating


to fit the purpose” and other treatment options related with water usage and water quality


objectives.


The management of wastewater through treatment has two major objectives: 1) To protect the


environment by reducing the pollution of fresh water resources, productive lands and hence


reducing health hazards. 2) To mobilize this available water resource for mitigating water


scarcity and improving crop production. Other simple option for farmers includes changes in


irrigation methods which can have low levels of risks. Using micro irrigation techniques to


irrigate vegetables, which can greatly reduce the risk of pathogenic contamination compared to


flood or furrow irrigation. The use of sewage in urban and peri-urban agriculture can also


improve water use efficiency in cities with limited water resources. Properly treated sewage


effluent can be used for ground water recharge, aquaculture and irrigation of lawns and urban


recreational parks and other non-potable uses. The best approach will need to balance both


farmers livelihood needs, and public health concerns. In future, water shortage and waste water


handling would be a major challenge in Pakistan. The result of increased attention to this issue


is expected to improve the health, economic and agricultural factors of developing community


in relation to waste water treatment and its re-use in agriculture sector.

Web Team
Author: Web Team

Technology Times Web team handles all matters relevant to website posting and management.

Support us by sharing this content :)
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  

Web Team

Technology Times Web team handles all matters relevant to website posting and management.

Leave a Reply