An Assessment on Different Solids, Dissolved Oxygen in Industrial Effluents and Its Impact on Public Health

Rapid industrialization is adversely impacting the environment globally. The study was carried out to evaluate the biophysical properties of samples contaminated by unplanned industrialization in terms of Effluent Treatment Plant (ETP) efficiency, availability and to evaluate the present scenario of water and air pollution by industrial discharges in order to create public awareness and its impact on public health. The study area was the second largest metropolis of Bangladesh, Chittagong. The study was carried out in 10 industries as a sampling station before and after treatment of industrial discharges and covered mainly two seasons, winter and dry seasons from November 2017 to June 2019. More than six parameters of effluents were analyzed. They are for total dissolved solids, total suspended solids, Total solids, dissolved oxygen, Chemical Oxygen Demand, Biochemical Oxygen Demand test etc. Collection, preservation and analysis of the samples were carried out in accordance with standard procedures. During analysis all precautions were taken in consideration. The ranges of results of waste water obtained were 25-453 mgL -1 for total suspended solids (TSS), 2128- 5,573mgL -1 for total dissolved solids (TDS), 2283-5709mgL -1 for Total solids, 2.25-7.01mgL -1 for dissolved oxygen, 27- 403mgL -1 for Biochemical Oxygen Demand (BOD), 80-1436 mgL -1 for Chemical Oxygen Demand (COD).Here almost all the parameters of industrial discharges are out of range prescribed by the Department of Environment (DoE),Bangladesh which is so much frightening for us. So, the properly untreated industrial discharges mainly heavy metals are deposited in our bodies through food cycle and through inhalation particulate matters which impacts on our body. In this research work, around 100 workers and neighbors of those selected industries has been studied and found to face different health problems like skin problem, vomiting, convulsion, eye irritating problem, headache, loss of IQ, diarrhea, nausea, decrease in memory and other health problems etc .

lead to serious environmental consequences [5]. This will also undoubtedly deteriorate soil productivity and adversely affect crop production in the surrounding land area. Industrial effluents had remarkable changes in the distribution of ions and their concentrations in wheat and bean plants [6]. The quality of dissolved minerals in water depends upon the source of water and its path before use [7]. As a consequence, pollution sources increase with the development of cities and it affects the environment in different ways by discharging the large amount of effluent as waste water in the surrounding water bodies, causing the serious problems to environment [8]. Due to deficiency of properly equipped plants and hygienic dumping sites controlled within the necessitated criteria, the industrial wastewater is discharged in an unplanned way to the environment. When the waste flow generally comprises a complex concoction of toxic matters preponderantly natural and synthetic organic contents, metals, and heavy elements, like wise as pathogens from industrial sectors enter into rivers, watercourses and other water bodies, they get dissolved or lie suspended in water bodies or lie suspended in water or get deposited on the bed [9]. This results in the pollution of water whereby the quality of the water deteriorates. Currently, only about 10% of the effluent generated is being processed; the rest is discharged as it is into our water bodies. Various categories of industries include garments, textile, spinning, pharmaceutical, food manufacturing industry but it is dominated by textile manufacturers, including dyeing and printing units moreover only a few of them have installed effluent treatment plant (ETP). Indiscriminate discharge of liquid waste by the industries has ruined fertility of agricultural land. Industrial liquid wastes have increased the sufferings of the villagers [10]. The DoE identified many polluting industries across the country, which have no treatment facilities for effluents and wastes. These heavily toxic effluents were discharging directly to adjacent soils and rivers [11]. The existing propensity of industrialization and urbanization diminishes the non-renewable resources and interrupts both the soil and surface water quality through promiscuous disposition of industrial effluents, solid wastes and other toxic wastes, which are the major environmental issues posing threats to the existence of human being [12]. Water pollution due to discharge of untreated industrial effluents into water bodies is a major problem in the global context [13]. The problem of water pollution is being experienced by both developing and developed countries. Human activities give rise to water pollution by introducing various categories of substances or waste into a water body [14]. The more common types of polluting substances include pathogenic organisms, oxygen demanding organic substances, plant nutrients that stimulate algal blooms, inorganic and organic toxic substances [15].

Materials and Methods
The study was carried out through experimental method. The sample was analyzed through experiment. Effluents from different industrial area, Chittagong and was compared with the standard level of wastewater quality parameters of DOE. Experimental data was collected and processed very carefully, and the experiments were performed at least three times to minimize analytical error.

Used Instruments
Water samples were analyzed for total dissolved solids (TDS) (by Combo meter) and metal test (by Hach DR 5000 metal test meter). Collection, preservation and analysis of the samples are carried out in accordance with standard procedures.

Study Area
Chittagong, the second largest metropolis of Bangladesh and the economic gateway of the country, is situated on the right bank of the river Karnaphuli. In this research work, nine sampling industries have been selected to collect the wastewater for laboratory analysis. Samples were collected from inlet wastewater and outlet water of different industries. A large amount of industrial effluent is discharged from different industries. During analysis all precautions were taken in consideration. The study was carried out in 10 industries as a sampling station before and after treatment of industrial discharges and covered mainly two seasons, winter and dry seasons between November 2017 to June 2019.

Sampling Techniques
Samples were collected in 100 ml Plastic bottles. All samples for laboratory analysis had been pre-washed with 10% nitric acid and rinsed with distilled water before use. Each bottle was rinsed

Dissolved Oxygen (DO)
reading was taken and finally the bottle was placed inside the refrigerator at 200°C of temperature for 5 days. After 5 days, the data was taken again trough the multi meter and the result was obtained.

Chemical Oxygen Demand (COD)
Turned on the reactor and preheated to 150°C. Hold the vial at 45-degree angle and 2ml of sample. Then the sample was mixed by inverting the vial. The sample was heated for two hours with a strong oxidizing agent. After the vial was placed inside, the spectrophotometer and compared it with the blank vial. Thus, the result was obtained.

Total Dissolved Solid (TDS)
TDS were measured after collection of samples within 5-10 minutes at the sampling spot by using Combo meter.

Total Solid (TS) and Total Suspended Solid (TSS)
100 ml of water sample was taken in a beaker or glass dish and evaporated to dryness in an oven at 103-105 0 C then cooled in a desiccator and weighed. Water that contains more than 1000 mg/L of dissolved solids usually contains minerals that give it a distinctive taste or make it unsuitable for human consumption. A maximum TDS value of 400 mg/L is permissible for diverse fish production.    As usual, there is no significant variation between dry and winter season due to industrial indoor analysis of sample (Figure 3a, 3b).
Comments: As we know that TS can be obtained by TSS plus TDS which are also reflected from the     (2.25 mg/L) of Olympic Paint industry is too low than acceptable limit of DoE which is so alarming for aquatic existence. Because, DO levels below 1 mg/L will not support fish; below 2 mg/L may lead to the death of most fishes. DO content should be above 6.0 mg/L for drinking water and more than 5.0 mg/L is suggested for fisheries and irrigation [6]. Adequate dissolved oxygen is necessary for good water quality. Oxygen is a necessary element to all forms of life. inorganic materials such as sulfides, ferrous ions and reduced forms of nitrogen. We know DO is inversely proportional to BOD. So, when DO level decreases then BOD will be increased and different types of microorganism will be formed, that's why water gets polluted.
From the Table 11, we observe that the discharging effluents of almost every industry contains high BOD level which ranges from 27 to 403 mg L -1 .

Health Problems of industrial effluents and emissions
Pollution is the largest environmental cause of disease and premature death in the world today. Diseases caused by pollution were responsible for an estimated 9 million premature deaths in 2015, 16% of all deaths worldwide, three times more deaths than from AIDS, tuberculosis, and malaria combined and 15 times more than from all wars and other forms of violence. In the most severely affected countries, pollution-related disease is responsible for more than one death in four [2].

Affected by Effluents
In this study, 100 workers and neighbors of that selected industries were under investigation from November 2015 to June 2019 aged between 18 to 60 years were enumerated and they informed, they must face frequently following health problems due to industrial degradation. It was descriptive type of crosssectional study with one step satisfaction.
It was an open question on predominant health problems in the selected industries. The respondents mentioned that skin diseases, diarrhea, gastric ulcers, and respiratory illnesses like common cold, asthma were the most common health problems amongst the workers and neighbors in the area. In addition, people also suffer from indigestion, hypertension, conjunctivitis, pneumonia, malaria, tuberculosis etc.
Most of the people (age between 41 to 60 years) involved in this study reported that they were suffering from mainly skin diseases, diarrhea, gastric ulcers or other gastric problems at the time that the research was taking place (Table 1).

5.
Health concern bodies to closely monitor the effluents from industries.
So, in these situations only practicable alternatives that must be maintained are dumping location should be properly managed to minimize its effects on the environment, proper laws should be strongly preserved and maintained, suitable distance from the surrounding water body should be maintained, appropriate laws on dumping of industrial effluents should be set up as well as some lessening measures should be taken for example, alertness should be also built up among the people about the environment degradation due to the discharging of industrial effluents. Our mass media should also come forward to aware people against this environment degradation. So, formal and informal methods of education might be adopted through local media, seminars, celebrations, workshops, walks and student competitions to aware the people regarding the process of environment degradation.